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BackgroundIn recent years, the rising number of e-cigarette users among adolescents and the surging cases of lung injury related to e-cigarette use have attracted the attention of researchers in various fields.ObjectiveTo identify the research hotspots and trends of e-cigarette or vaping product use associated lung injury (EVALI) worldwide from 2013 to 2022 by bibliometric and visual analysis. MethodsWeb of Science Core Collection was selected to obtain literature related to EVALI from 2013 to 2022 across the world, statistics were calculated by country/region, institution, author, journal, cited literature, keyword, etc. CiteSpace 6.2.R1 was used for visual analysis to draw diagrams of publication trend, author cooperation network, co-citation clustering time distribution, and keyword cluster. ResultsA total of 888 EVALI-related papers published between 2013 and 2022 were retrieved. The number of publications was gradually increased, with a significant increase in 2020 and a decrease from 2021, but the number of citations was increased year by year. The most active country was the United States (631 articles). European and American countries cooperated closely and the centrality was prominent. Among the publishing institutions, the University of California system topped the list with 103 articles. Rahman I (27 articles) published the most articles and had a high degree of centrality; Goniewicz M L was the most cited author; and the network analysis diagram showed relatively weak collaboration between authors. The American Journal of Respiratory and Critical Care Medicine was the journal with the highest number of publications (94 articles). The top 5 cited articles were all cited more than 300 times. The leading high-frequency keywords of EVALI-related studies were nicotine (149 times), exposure (118 times), and oxidative stress (80 times). The cluster of key nodes in the co-citation network and the clustering time distribution diagram indicated youth e-cigarette addiction received widespread attention from society. From the top 25 keywords with the strongest bursts, the focus of research on the pathogenesis of EVALI gradually shifted from the oxidative stress damage associated with e-cigarette vapor to the oxidative effect of flavoring chemicals in the process of lung injury. The current research interests in this field were mainly the mechanisms of various chemicals in e-cigarettes and the heating elements that led to damage to the lungs. ConclusionEVALI is receiving continuous attention from researchers in government, medical institutions, and other organizations. A variety of e-cigarette ingredients such as flavoring chemicals may lead to varying degrees of cytotoxicity, inflammation, and lung damage. However, the pathophysiology of EVALI remains unclear. In the future, more Chinese scholars should be encouraged to participate in this field.

Since its inception by Dr. Kabat-Zinn, Mindfulness-Based Stress Reduction (MBSR) has led to various mindfulness interventions and gained positive feedback in many fields. This paper extracts the shared mindfulness mechanisms emphasized by Kabat-Zinn’s MBSR and the Buddhist “Four Foundations of Mindfulness,” assesses their applicability to mindfulness education, and compares their differences in objectives and skills, serving as a reference for the future development of mindfulness education in Taiwan. The study finds that mindfulness education in Taiwan mainly follows Kabat-Zinn’s guidance, focusing on basic practices of “body, feelings, and mind,” with less involvement in higher-level psychological insights. In the aspect of “dharmas,” Kabat-Zinn incorporated Zen concepts, a practice that has seen limited attention and utilization in Taiwan, which also rarely addresses goal-oriented elements. This paper suggests that mindfulness education in Taiwan should emphasize the guidance of “impermanence and non-self” and the systematic thinking of “dharmas,” striving to present these concepts in accessible language to mitigate concerns over religiosity. To enhance mindfulness education in Taiwan, two key areas should be addressed: first, the scope of mindfulness research and practice should expand to include “higher-level psychological qualities”; second, government authorities should consolidate resources to establish a mindfulness research and teacher training center, aiming to develop a comprehensive and practical pedagogical framework. Only with solid academic research and institutional support can mindfulness education in Taiwan be truly strengthened, thereby enhancing public well-being and promoting holistic development.

In the 1920s, the statistician Ronald Fisher introduced a statistical theory system based on probability calculations and evaluations. Fisher coined the term “p-value” to denote the probability of observing the obtained results, assuming that the independent variable is not influenced or manipulated. This calculation helps evaluate the likelihood of such results within the research context. Later, Neyman and Pearson proposed the concepts of null hypothesis and alternative hypothesis, advocating for the inclusion of both in the hypothesis testing. While the two approaches to testing statistical hypotheses were different, these approaches were later integrated into what is now known as null hypothesis significance testing, with the p-value as a standardized measure for statistical analysis. In recent years, however, the academic community has identified a concerning trend known as “p-hacking,” where researchers misuse or abuse data analysis to achieve misleading statistical significance. Then, researchers claim to have speciously successful experiments and publish the implausible research results in journals. This paper focuses on p-hacking within quantitative educational research, exploring its origins, definition, technique, impact, and how journals prevent the manipulation of p-hacking. Finally, this paper reinstates the correct perception of p-value with recommendations for preventing p-hacking, including providing evidence of practical significance while presenting statistical significance, ensuring replicability of research results, stating the structure and details of statistical analysis, and judicious selection of appropriate analytical techniques.

Silicon carbide (SiC) is an important material for shielding nuclear fission products in tri-structural isotropic (TRISO) particles for high-temperature gas-cooled reactors. It has an important influence on the safety performance of TRISO particles. Therefore, it is necessary to study the irradiation behaviors and mechanical properties of the SiC layer of TRISO particles. The irradiation process and nanoindentation process can be described accurately by molecular dynamics simulations. It is helpful to analyze the irradiation behavior and mechanical properties of materials. In this paper, molecular dynamics simulations were used to study the irradiation behavior of equiaxed polycrystalline and long-axis polycrystalline SiC layers obtained from experiments. The calculated theoretical values of the irradiation swelling degree and mechanical properties of the SiC layer are in good agreement with the experimental values. It shows the strong applicability of the potential functions and other simulation system parameters used in this paper. The irradiation behavior of the SiC layer was studied in detail by swelling degree, density, atomic structure type, and point defect evolution. The results show that the grain structure of the SiC layer has no significant effect on its irradiation swelling and amorphization. The amorphization is not directly converted from the crystal structure to the amorphous structure during the irradiation process. The crystal structure is converted into an intermediate state structure and then converted into an amorphous structure. The point defects are mainly C vacancies, Si interstitial atoms, and C antisite atoms in the early stage of irradiation. The difference between the ratio of C point defects and Si point defects gradually disappears after the irradiation dose tends to be saturated. The evolution of amorphization and point defects tends to start nearby the grain boundaries. Irradiation reduces the mechanical properties of SiC layers. It no longer has a significant effect on the mechanical properties of the SiC layer after the irradiation dose tends to be saturated. The changes in the mechanical properties of the SiC layer before and after irradiation were analyzed by load-depth curve and stress & strain. The results show that the decrease in mechanical properties of the SiC layer is closely related to the mechanical behaviors under external force. For example, the bearing capacity and plastic deformation degree decrease, and the stress & strain distribution are disordered. The results provide a quantitative explanation for the irradiation behavior of the SiC layer of TRISO particles and the change of mechanical properties under irradiation. It is helpful to understand the irradiation behavior and relationship between the irradiation behavior and mechanical properties of the SiC layer.

The mathematical model of a radio frequency (RF) system incorporates crucial characteristic parameters of an RF cavity, including the cavity bandwidth, the resonant frequency, and Lorentz force detuning factors, which is very important for the cavity performance evaluation, the control system simulation, and the optimization of low-level control algorithms. A network analyzer is usually used to measure scattering parameters and subsequently construct mathematical models of a RF system. However, the measurement steps are tedious and fail to identify the system model online. Therefore, an advanced online identification algorithm was described for RF cavity systems in this paper, which simulated the operational principles of a network analyzer. This algorithm was integrated within a digital low-level RF (LLRF) system and consisted of a high-precision numerically controlled oscillator, a frequency control word generator module, an amplitude-phase calculation module, and a sweep frequency amplitude-phase processing module. With the assistance of the Matlab/Simulink platform, which provides an ideal environment for simulation and analysis, the deployment of this algorithm was ultimately realized on the field-programmable gate array (FPGA) chip of the low-level system, accomplishing the online identification of RF systems. Then, the sweeping algorithm was verified on a superconducting cavity of the China Accelerator Driven System Front-end Demo Linac at the Institute of Modern Physics. During the verification process, the half-bandwidth of all cavities in CM1 was accurately measured using an online identification algorithm, and the half-bandwidth of all cavities corresponding to CM1 was also measured utilizing a network analyzer. The results of half-bandwidth measured by the two methods are in good agreement, strongly supporting the validity of the online identification algorithm for cavity system models proposed in this paper. Furthermore, we successfully measured the distortion curve of cavity frequency response caused by Lorentz force detuning. Finally, the influence of Lorentz force detuning variation on the measurement of the critical cavity parameters was discussed in this paper. As the RF peak electric field increases, the radiation pressure within the cavity rises proportionately, leading to a corresponding increase in Lorenz force detuning. This article demonstrates that when the RF peak electric field of the cavity operating is less than 16 MV/m, Lorenz force detuning has a relatively limited impact on the bandwidth measurement of the cavity. Conversely, once the peak acceleration electric field surpasses this threshold, Lorenz force detuning exerts an unnegligible effect on the measurement of the half-bandwidth of the cavity. The specific mechanisms of the Lorenz force detuning’s influence on the half-bandwidth of the cavity will be further studied in future research.

Purposes As the "world's oldest overpass", the Flying Bridge across Fish Ponds in Jinci Temple highlights the cultural characteristics of ancient buildings in Shanxi. Methods In this paper, the compressive strength of the stone pillars of the Flying Bridge across Fish Ponds in Jinci Temple was tested with the rebound meter. AutoCAD software was used for three-dimensional modeling according to the mapping paper, and Abaqus finite element analysis software was used to simulate and analyze the overall stability under static load and seismic action. Findings The results show that under static action, for the Flying Bridge across Fish Ponds, the stress of the components is much less than the allowable value, and the settlement of the foundation is small and tends to be stable. Under the action of earthquake, the structural force is uniform and symmetrical, the top surface displacement is the largest, the third main stress of the stone column is mainly concentrated on the foot and the top of the column, and along the seismic wave loading direction, the oblique section develops, the stress is also less than the allowable value, and has good seismic stability. The results of this work can provide a reference for future conservation work of the Flying Bridge across Fish Ponds.

Deoxynivalenol (DON) is a toxic secondary metabolite produced by Fusarium spp. that mainly contaminates wheat, corn, and other food crops, and has posed serious threats to food safety. Currently, enzymatic detoxification of DON shows promising application prospects. This paper provided an overview of the latest domestic and international research on the types of biotransformation enzymes, degradation mechanisms, structural features, detoxification enzyme mining strategies, and molecular modifications of DON. Additionally, the paper explored research trends in molecular design of mycotoxin detoxification enzymes assisted by artificial intelligence, which aimed to provide a reference for the development of bio-detoxification technology of DON in food and feed.

The liquid metal cooled fast reactor has significant strategic significance for the innovative development of nuclear energy, and the development of fuel performance analysis programs suitable for liquid metal cooled fast reactors is of great significance for the design and safety analysis of fast reactors. Fuel elements are one of the most fundamental components of nuclear reactors, and analyzing their performance is one of the most challenging tasks in reactor development. The fuel element performance analysis program LoongCALF based on the multi-physics coupling platform MOOSE was developed in this paper. This program aimed to simulate the long-term service performance evolution of fuel elements under steady-state conditions, providing scientific basis for the design, service life prediction, and safety evaluation of LMFR fuel elements. The program was aimed at metal cooled fast reactor fuel elements, and based on finite element method and JFNK method, solved the thermal mechanical coupling equation of nuclear reactor fuel, and obtained the spatial distribution and temporal variation of physical quantities such as temperature, stress, strain, and fission gas release. The program used a 1.5-dimensional modeling method to perform multi-physics field coupling calculations on fuel rods. In addition, the program supported one-dimensional, two-dimensional, and three-dimensional mesh modeling calculations to meet the construction requirements of fuel element models of different sizes and shapes. The program adopted a modular design with separate material modules. Currently, the fuel types supported by the program include UO2 and MOX, the cladding materials include HT9 and 1515Ti, and the coolant materials supported sodium, lead, and lead bismuth. To verify the accuracy of the program, two benchmark examples were designed for numerical simulation and calculation in this paper. Example 1 used UO2 as the core material and 1515Ti as the cladding material; Example 2 used MOX as the core material and HT9 as the cladding material. By comparing and calculating with the Fiber-Oxide program of the Chinese Institute of Atomic Energy, it is found that the two programs show good consistency in key parameters such as core cladding temperature, displacement, stress, and fission gas release fraction. Although there are certain differences in the handling of repositioning and fracture models, resulting in some deviation in the initial calculation results, considering the limitations of the empirical models used in fuel performance analysis programs, this difference is still within an acceptable range. In summary, the LoongCALF program can accurately simulate the fuel behavior and key parameter evolution inside fuel elements under steady-state operating conditions of liquid metal cooled fast reactors. In the future, we will rely on more practical measurement cases to conduct deeper verification and optimization of the LoongCALF program, to ensure its accuracy and reliability in fast reactor design and safety analysis.

The deterministic two-step method for the fast reactor neutronics calculation, composed of cross-section homogenization and diffusion or transport core calculations, was widely applied in the fast reactor engineering design and analysis field. The homogenized cross-section calculation method based on Monte Carlo with continuous-energy and fine geometry can provide high-precision cross-sections for advanced fast reactors. The current development status and trends of coupling Monte Carlo-generated homogenized cross-sections with diffusion and transport core calculations were briefly reviewed in this paper. The methods discussed include the Monte Carlo flux-volume homogenization method, the superhomogenization equivalence technique (SPH), and the Monte Carlo flux-moment homogenization method (MHT). The MET-1000 metal fuel fast reactor is used as a benchmark. The SPH equivalent techniques are widely used to preserve the reaction rates of a reference heterogeneous model and a homogenous model. In this paper, the SPH was applied to the control rods' cross-section address to improve the diffusion core calculations. This equivalence technique reduces the overestimation of the control rod worth using the diffusion core solver from 13.5% to 0.35% and improves power distribution prediction accuracy. With SPH correction, the MC/diffusion in this work exhibits about

The method of characteristics has very strong geometric adaptability and can be used to solve the 3-D whole core problem of high temperature gas-cooled pebble-bed reactor. However, it suffers from the disadvantages of thousands of iterations and slow calculation speed. At present, there have been some attempts to reduce calculation time for method of characteristics, including coarse mesh finite difference (CMFD), general coarse mesh rebalance (GCMR) and general coarse mesh finite difference (GCMFD). The CMFD method is applied to realize the acceleration of regular region like squares. Furthermore, to break through the limitation of macroscopic regular geometry for the numerical acceleration method, researchers successively propose the GCMR method and the GCMFD method, but these methods are very complex to implement in irregular geometries and some approximation factors must be introduced. Based on the analysis of more dense tracks are arranged for the 3-D model, the sparse macro-track transport acceleration method was proposed, which greatly reduces the calculation amount of the acceleration equation and obtains a very good acceleration efficiency without reducing the accuracy. The 2-D method of characteristics divides the angular space into M azimuthal angles and P pole angles. The 3-D method of characteristics generally uses a level symmetric quadrature set. In 2-D geometry, the angle is relatively more dense at the poles. As a result, the 2-D macro-track transport acceleration can select a small number of azimuth angles with reflection symmetry and one pole angle as the solution directions of the acceleration equation. The sparse macro-track transport acceleration method implemented in this paper used the same angles as the method of characteristics. The number of tracks for 3-D problems is an order of magnitude higher than for 2-D problems. That is why reducing the number of 3-D tracks is a promising method for reducing the amount of accelerated equation calculation. This paper applied the macro-track transport acceleration method to 3-D whole core problem of high temperature gas-cooled pebble-bed reactor to solve the problem of irregular geometric numerical acceleration. The sparsity, macro-track length limit, and the maximum iteration step limit of the macro-track method are the main factors that affect the acceleration performance. The selection method of acceleration parameters was studied through two benchmark problems. Excellent speedup ratio can be obtained by setting the sparsity to 3-5, the macro-track length to around 2.0 cm, the acceleration iteration steps limit to 20-60. The results of 3-D small light water reactor benchmark and simplified pebble-bed reactor core model show that about 7 times the time speedup ratio and about corresponding 20 times the iterative step speedup ratio can be achieved.

In this paper, the main literature related to 4DCT imaging and reconstruction techniques over the past 20 years is reviewed, and the contents are summarized. This paper provides a systematic and comprehensive introduction to 4DCT research from five perspectives: the concept of 4DCT, scanning mode and imaging method, reconstruction algorithm, application, research status, and future development expectations. In this study, five types of reconstruction algorithms are summarized, and the advantages, disadvantages, and research difficulties of each algorithm are briefly evaluated. Finally, we conduct a brief statistical analysis on the cited works from the perspective of reconstruction methods, revealing the research progress and future research trends of 4DCT reconstruction algorithms.

ObjectivesIn order to effectively broaden the beam width of the 3 dB axis ratio of a Beidou antenna, this paper proposes a slotted laminated microstrip patch antenna loaded with parasitic elements. MethodsThe Beidou dual frequency band feature is realized through a two-layer substrate structure. The bandwidth is widened by slotting. Circular polarized radiation is achieved by cutting corners at the edge of the patch. At the same time, L-shaped parasitic elements are loaded around the patch to broaden the 3 dB axial ratio beam width of the antenna.ResultsThe measured and simulated results are in good agreement. The relative bandwidths of the antenna in the Beidou B1 and B2 bands are 3% and 7.5%. The beam width of the 3 dB axis ratio can reach 180° and 176°, and the maximum gain can reach 6 dBi. In the Beidou receiver test, the number of antenna satellites can reach more than 17, and the positioning accuracy is within meters. ConclusionsThis paper proposes and validates a high-precision positioning dual band Beidou navigation antenna with wide axis ratio beam width. The results can provide references for the design of small Beidou navigation antennas.

Lagerstroemia is a native plant in China, which has been cultivated for more than 1 500 years. It is an excellent summer flower woody plant, and is widely used in urban landscaping because of its beautiful color, long flowering period and the advantage of purifying air. The germplasm resources of Lagerstroemia indica are extremely rich. There are about 60 species of Lagerstroemia in the world, 40% of which are in China. The results of national and regional investigations have laid a good foundation for the study of L. indica. In recent years, the cultivation and application of new cultivars have been increased in various regions. The breeding method is mainly traditional breeding, and many new cultivars with good characters and high market value have been cultivated. With the rapid development of breeding technology and molecular biology, a breakthrough has been made in the researches on molecular assisted breeding of L. indica. In this paper, the classification research, germplasm resources, breeding research and introduction and application of L. indica were reviewed. We systematically sorted out the germplasm resources of L. indica in China, including 24 wild species and 350 cultivars, discussed the research process and development trend of breeding of L. indica at home and abroad, and summarized the current situation of introduction and application research. In regard to the current research status of L. indica, this paper offered reflections on future research directions to enhance investigations of L. indica, improve germplasm resource banks, and establish information sharing channels; efforts on breeding should be expanded beyond flower color, fragrance, plant type, resistance and extension of flowering period; and biological and intelligent technologies should be leveraged to strengthen breeding techniques and accelerate innovation in L. indica germplasms. Continuous application forms for L. indica resources should be developed according to local conditions to fully realize their value.

BackgroundThe development of railways has a long history, but there is limited research on the health of railway workers at home and abroad. China's high-speed railway development has attracted worldwide attention in recent years, and it is of great significance to study how to promote the health of this occupational population to ensure the safety of railway transportation. ObjectiveTo identify development trends and hotspots in the field of railway workers' health at home and abroad. MethodsThe research literature related to the health of railroad workers dated from January 1, 1973 to December 31, 2022 was searched using the China Knowledge Network Infrastructure (CNKI) and Web of Science Core Collection (WoS) databases. After screening and cleaning, the included literature was subjected to bibliometric analysis by applying CiteSpace 6.1R6 software to visualize and analyze literature co-citation, keyword emergence, and keyword timeline graphs, and by VOSviewer 1.6.19 to visualize and analyze country/region collaboration, keyword co-occurrence, and keyword clustering. ResultsDuring the period from 1973 until 2022, a total of 273 Chinese literature and 165 English literature were found to report studies related to the health of railway workers. The Chinese literature began to grow rapidly in 2009 and peaked in 2015, and the number of English literature published in a relatively flat state over the studied period. The country with the most papers indexed by Science Citation Index (SCI) was the United States (58 papers), which also presented the richest international collaborations. The document with the highest domestic citation frequency was published in the Chinese Journal of Mental Health in 1994, and the document with the highest SCI citation frequency was published in the American Journal of Epidemiology in 1994. The keyword co-occurrence analysis showed that the included Chinese literature mainly focused on health checkups, health management, hypertension, mental health, and chronic diseases and their prevalence; the included English literature focused on mortality, lung cancer, epidemiology, and diesel engine exhaust and its exposure. The analysis of emergent words showed that health management, frontline workers, and occupational stress were the topics of interest in Chinese literature in the last five years, while occupational stress, diesel exhaust emissions, and noise exposure were the topics of interest in English literature in the last ten years. The results of the timeline graph analysis suggested that the recent research directions in Chinese literature were health intervention, humanistic care, staff canteens, etc. There were few English-language articles related to this area after 2010. ConclusionThe research hotspots of railroad practitioners' health will keep changing with the development of high-speed railways in countries around the world. The outstanding rise of Chinese literature issued in the last decade has been in striking contrast to the slow progress and decreasing of English literature. The Chinese literature has gradually expanded the hotspots from chronic diseases to health management, occupational stress, and sleep disorders.

The nuclear reactor system is complex and the operating environment is harsh, resulting in the complex phenomena of multi-physics coupling. The multi-physics coupling codes developed in the early stage shows limitations on codes' scalability and generality. Therefore, it is of great significance to build a multi-physics coupling framework and conduct research on key technologies in coupling problems, which may accelerate the development process of autonomous multi-physics coupling platform in China. In this paper, the multi-dimensional and multi-physics coupling finite element analysis platform for nuclear reactor developed by XJTU-NuTHeL was introduced. The main work consisted of the development of thermal-hydraulic model, the research of fuel performance analysis technology and the establishment of multi-physics coupling framework. In terms of thermal-hydraulic calculation, XJTU-NuTHeL conducted a series of studies on pressurized water reactors and advanced reactors grounded in the advanced multi-physics coupling framework, and developed the nuclear reactor system safety analysis code, NUSAC. In addition, a subchannel analysis model tailored for liquid metal fast reactors was established, and the fully coupled subchannel transient analysis code, FLARE, was developed. NUSAC and FLARE were then verified against relevant codes and experimental data. In the realm of fuel performance analysis, considering the wide application of finite element method in solid mechanics and its versatile modeling capabilities, XJTU-NuTHeL developed a fuel performance analysis code, BEEs, based on finite element method. The code could not only conduct multi-physics coupling analysis for traditional rod fuels under steady and transient conditions, but also extends its applicability to accident tolerant fuels and other fuels with diverse geometric shapes. This paper focused on the study and analysis of coated particle dispersed fuel and plate type fuel. The multi-scale simulation results of coated particle dispersed fuels, as well as the thermomechanical and corrosion behavior of plate type fuels were shown. In the context of multi-physics coupling analysis, the efficiency and accuracy of different mesh grid mapping schemes were studied and a multi-physics coupling framework was established. An example of the framework was then presented, showcasing the integration of the fuel performance code BEEs, the Monte Carlo neutron physics code OpenMC, and reactor system safety analysis code NUSAC. The keys parameters of mechanics, thermal-hydraulic and neutronics were obtained and analyzed through the coupling different codes. The multi-dimensional and multi-physics coupling finite element analysis platform built in this paper can provide a strong support for the high-fidelity numerical simulation of nuclear reactor multi-scale and multi-physics coupling.

To prevent severe safety accidents caused by primary coolant leakage in pressurized water reactors (PWRs), it is necessary to monitor the leakage rate of key parts of the reactor coolant pressure boundary (RCPB) in order to take timely countermeasures. The primary coolant of PWRs is usually high-pressure supercritical water containing boron, which can produce 18F in the high neutron flux environment of the reactor. The leak rate of the RCPB can be inferred by measuring the activity concentration of the radioactive 18F aerosol produced by the coolant leaking into the containment. A measurable sample source is usually obtained by extracting sample gas containing 18F aerosol from the containment and filtering it in the monitor. The measurement method used by the monitor is to screen the γ signal by using the β signal as the gate signal, which is actually a γ relative measurement method using the coincidence method to reduce the background. The electronic design of the monitor prevents the β-channel signal from being recorded, which makes it impossible to achieve the absolute measurement as with conventional coincidence methods. To ensure the accuracy of the monitoring results, the 18F aerosol monitor needs to be calibrated. In this paper the monitor was calibrated using a standard 18F surface source produced by the intermittent spot method on a filter paper base. By means of the decay of the 18F source and the automatic recording function of the monitor, the indication number of the monitor was measured at six source activities of different orders of magnitude, i.e. the count of the energy spectrum at the position of the 511 keV γ-window. The data were used to obtain the activity response and uncertainty of the monitor's readings and to verify the feasibility of such a calibration scheme on the monitor. Two standard point sources of 22Na and 68Ge/68Ga were also used to calibrate the monitor to verify the feasibility of using long-lived nuclides to make alternative sources for calibration. Sets of 511 keV γ-window count data from γ and coincidence channels were recorded to investigate the effect of the γ coincidence additive effect and different β emission spectra on the activity response, and to determine which long-lived positron nuclides should be used in the field calibration. Calibration with a standard 18F surface source shows that the monitor can give stable and reliable readings of this type of standard source over different orders of magnitude within the range. The extended uncertainty (k=2) of the displayed activity response is 6.0%, which meets manufacturing requirements. And the calibration of the long-lived positron nuclide standard point sources shows that the positron spectrum has a great influence on the activity response of the monitor, and the γ coincidence additive effect is not very significant. Therefore, it is recommended to use 22Na with β energy close to 18F to make point sources or surface sources for field calibration.

The focal spot size of X-ray tube is one of the key factors affecting the imaging resolution, and it is also an important index to characterize the working performance of the X-ray source. Typically, after the X-ray tube is manufactured, the focal spot size must be measured and marked. Nowadays, the most widely used measurement standards for X-ray tube focal spot size in the world are IEC 60336, EN 12543, and ASTM E1165. Between various standards, there are differences in the focal spot size measurement methods, scope of application, loading factors and imaging equipment. Among these, the slit method of EN 12543 standard is mostly utilized in industrial X-ray tubes. However, due to its complex and precise design requirements, the test equipment, i.e., the slit camera, is difficult to produce and process, and the cost is high, which is not conducive to promotion and application. This paper studied the influence and variation of the measurement of the focal spot size at different slit sizes by using double tungsten alloy cylinders instead of slit camera. Based on the calibration of distance and position parameters in the cylinder method, the measurement equipment was conveniently positioned, and the distance between the focal spot and the translation mechanism was measured simultaneously, which improves the position accuracy of the focal spot size measurement. Additionally, the formula for determining the focal spot size in the slit method was improved, so that the slit method can be applied to a wide range of slit widths. In particular, the geometric magnification of the system can be measured directly when the slit width is large, skipping the step of measuring the distance between the focal spot and the translation mechanism. The experiment scheme has low requirements on the centering conditions of the equipment and the distribution of the X-ray source. In the data processing process, dark field correction and bright field correction were used to eliminate the problem of inconsistency in the response characteristics of each detector pixel, and the Wiener Filtering was performed on the signal output by the detector to deal with Gaussian noise and uniformly distributed noise. The experiment results show that relatively accurate measurement values can be obtained by measuring MXR-225HP/11 with double tungsten alloy cylinders with the same spacing as the focal spot size. The measurement relative error is less than 10%. According to international standards, when the measurement results are within plus or minus 10% of the theoretical value, it can be used as a method to determine the focal spot size. Therefore, the improved method in this paper is reliable and does not require high testing equipment, allowing it to be widely used. In addition, the geometric magnification of the focus measurement device can be directly calculated when the slit width is larger than the focal spot size, and the calculation results are consistent with the results measured in the cylinder method.

This paper proposes a radar signal transceiver framework that combines single-bit sampling and time division multiplexing receivers to satisfy the application requirements of low-cost lightweight radars. Firstly, this paper explains the advantages of saving the number of receivers by introducing the working principle of the framework. From the perspective of radar resource allocation, the importance of single-bit sampling in this framework was analyzed; additionally, the proposed framework can achieve better performance than a classical linear frequency modulation continuous wave radar using time and space exchange. Subsequently, the formulas for range, velocity and angle measurement were derived, along with the Cramér-Rao bound for estimating target parameters. Accordingly, the performance advantages of the proposed framework were verified, and the signal-to-noise ratio conditions for its stable operation were determined. Finally, this paper verifies the accuracy of the target acquisition principle of the proposed framework and the reliability of the performance analysis by using a velocity dimensional pairing algorithm based on single-bit two-dimensional multiple signal classification.

With the growing demand for radar target detection, Sparse Recovery (SR) technology based on the Compressive Sensing (CS) model has been widely used in radar signal processing. This paper first outlines the fundamental theory of SR and then introduces the sparse characteristics in radar signal processing from the perspectives of scene sparsity and observation sparsity. Subsequently, it explores these sparse properties to provide an overview of CS applications in radar signal processing, including spatial domain processing, pulse compression, coherent processing, radar imaging, and target detection. Finally, the paper summarizes the applications of CS in radar signal processing.

Orthogonal Frequency Division Multiplexing (OFDM) waveform design is one of the key physical layer technologies for achieving joint radar-communication. OFDM waveforms usually have issues with high Peak to Average Power Ratio (PAPR) and high waveform autocorrelation sidelobe levels. This paper proposes an integrated waveform design method based on data distortion to address the communication rate degradation problem of existing joint PAPR and autocorrelation sidelobe reduction methods. The paper also takes the Error Vector Magnitude (EVM) of communication data as one of the optimization objectives, reducing the communication bit error rate caused by data distortion. Firstly, an optimization model was constructed to minimize the Integrated Sidelobe Level Ratio (ISLR) and EVM under PAPR constraints. Secondly, based on the characteristics of the modulation constellation, the multi-objective high-dimensional non-convex optimization problem is transformed into two single objective optimization subproblems by using the data distortion of outer constellation modulation and all modulation data distortion. Convex relaxation operation and Alternating Direction Method of Multipliers (ADMM) are respectively used to solve the simplified subproblems, resulting in low ISLR waveform and low EVM waveform under PAPR constraint. The simulation results show that the integrated waveform designed by the proposed method can meet the requirements of PAPR, and has good sensing and communication performance.

Time Domain Coding Metasurface (TDCM) is an emerging technology enabling dynamic modulation of electromagnetic waves. In response to the control characteristics of this technology, this paper presents a radar jamming method based on TDCM intrapulse and interpulse coding optimization. First, optimization models are established in fast and slow time domains. By optimizing intrapulse and interpulse phase coding, the energy redistribution of targets is achieved, thereby generating deceptive interference on the range-Doppler two-dimensional plot. Subsequently, a genetic algorithm is employed to solve this discrete optimization problem. Furthermore, this paper analyzes the effect of various modulation factors on interference effectiveness in terms of TDCM coding strategies, providing guidance for achieving optimal strategies for deceptive interference.

Data governance capability is fundamental to coal mine intelligence construction. It could accelerate the intelligent construction of coal mines and promote the digital transformation of the coal industry so as to building a modern energy system in digital China. This paper therefore discusses the theory and methods of improving data governance capability for intelligent coal mines. Specifically, this study analyzes its strategic demands of intelligent coal mine construction on data governance and offers a working definition for data governance capability for intelligent coal mines. Then an evaluative system is proposed for the evaluation of data governance capability for intelligent coal mines. Further, by drawing on capability maturity theory, this study establishes a maturity model that specifies the improvement path of data governance capability for intelligent coal mines. Finally, based on the PDCA cycle theory, this paper puts forward strategies for improving data governance capability for intelligent coal mines, in order to 1)supplement existing theories of data governance capability enhancement, and 2)provide references for future practices of data governance.

ObjectiveKnowledge services in agricultural scenarios have the characteristics of long periodicity and prolonged activity time. Traditional recommendation models cannot effectively mine hidden information in agricultural scenarios, in order to improve the quality of agricultural knowledge recommendation services, agricultural contextual information based on agricultural time should be fully considered. To address these issues, a Time-aware and filter-enhanced sequential recommendation model for agricultural knowledge (TiFSA) was proposed, integrating temporal perception and enhanced filtering.MethodsFirst, based on the temporal positional embedding, combining the temporal information of farmers' interactions with positional embedding based on time perception, it helped to learn project relevance based on agricultural season in agricultural contexts. A multi-head self-attention network recommendation algorithm based on time-awareness was proposed for the agricultural knowledge recommendation task, which extracted different interaction time information in the user interaction sequence and introduced it into the multi-head self-attention network to calculate the attention weight, which encoded the user's periodic interaction information based on the agricultural time, and also effectively captured the user's dynamic preference information over time. Then, through the temporal positional embedding, a filter filtering algorithm was introduced to adaptively attenuate the noise in farmers' situational data adaptively. The filtering algorithm was introduced to enhance the filtering module to effectively filter the noisy information in the agricultural dataset and alleviate the overfitting problem due to the poorly normalized and sparse agricultural dataset. By endowing the model with lower time complexity and adaptive noise attenuation capability. The applicability of this method in agricultural scenarios was improved. Next, a multi-head self attention network with temporal information was constructed to achieve unified modeling of time, projects, and features, and represent farmers' preferences of farmers over time in context, thereby providing reliable recommendation results for users. Finally, the AdamW optimizer was used to update and compute the model parameters. AdamW added L2 regularization and an appropriate penalty mechanism for larger weights, which could update all weights more smoothly and alleviate the problem of falling into local minima. Applied in the field of agricultural recommendation, it could further improve the training effect of the model. The experimental data came from user likes, comments, and corresponding time information in the "National Agricultural Knowledge Intelligent Service Cloud Platform", and the dataset ml-1m in the movie recommendation scenario was selected as an auxiliary validation of the performance of this model.Results and DiscussionsAccording to the user interaction sequence datasets in the "National Agricultural Knowledge Intelligent Service Cloud Platform", from the experimental results, it could be learned that TiFSA outperforms the other models on two different datasets, in which the enhancement was more obvious on the Agriculture dataset, where HR and NDCG were improved by 14.02% and 16.19%, respectively, compared to the suboptimal model, TiSASRec; while on the ml-1m dataset compared to the suboptimal model, SASRec, HR and NDCG were improved by 1.90% and 2.30%, respectively. In summary, the TiFSA model proposed in this paper has a large improvement compared with other models, which verifies verified the effectiveness of the TiFSA model and showed that the time interval information of farmer interaction and the filtering algorithm play an important role in the improvement of the model performance in the agricultural context. From the results of the ablation experiments, it could be seen that when the time-aware and enhanced filtering modules were removed, the values of the two metrics HR@10 and NDCG@10 were 0.293 6 and 0.203 9, respectively, and the recommended performance was poor. When only the time-aware module and only the augmentation filtering module were removed, the experimental results had different degrees of improvement compared to TiFSA-tf, and the TiFSA model proposed in this paper achieved the optimal performance in the two evaluation metrics. When only the multi-head self-attention network was utilized for recommendation, both recommendation metrics of the model were lower, indicating that the traditional sequence recommendation method that only considered the item number was not applicable to agricultural scenarios. When the augmented filtering module was introduced without the time-aware module, the model performance was improved, but still failed to achieve the ideal recommendation effect. When only the time-aware module was introduced without the augmented filtering module, there was a significant improvement in the model effect, which proved that the time-aware module was more applicable to agricultural scenarios and can effectively improve the model performance of the sequence recommendation task. When both time-aware and augmented filtering modules were introduced, the model performance was further improved, which on the one hand illustrated the dependence of the augmented filtering module on the time-aware module, and on the other hand verified the necessity of adopting the augmented filtering to the time-aware self-attention network model.ConclusionsThis research proposes an agricultural knowledge recommendation model that integrates time-awareness and augmented filtering, which introduces the user's interaction time interval into the embedded information, so that the model effectively learns the information of agricultural time in the agricultural scene, and the prediction of the user's interaction time and the object is more closely related to the actual scene; augmented filtering algorithms are used to attenuate the noise in the agricultural data. At the same time, the enhanced filtering algorithm is used to attenuate the noise in the agricultural data, and can be effectively integrated into the model for use, further improving the recommendation performance of the model. The experimental results show the effectiveness of the proposed TiFSA model on the agricultural dataset. The ablation experiments confirm the positive effect of time-awareness and enhanced filtering modules on the improvement of recommendation performance.

This paper aims to comprehensively analyze the Alfven instability observed in the high βN discharge of EAST, considering both experimental observations and simulation studies. There are two purposes of this paper, the first one is to observe the AE activity in EAST, the second one is to apply and validate the FAR3d code in EAST. In the experimental analysis, the presence of a strong instability is detected using magnetic probes and electron cyclotron emission diagnostics. Two kinds of modes are observed:one's frequency ranging from approximately 70 kHz to 100 kHz, exhibiting an upward frequency sweep, and another frequency at around 60 kHz. These instabilities are found to destabilized near ρ=0.46 with a toroidal mode number of 2 calculated by toroidal Mirnov probe array. Complementing the experimental findings, simulations were performed using the eigensolver method of the FAR3d code. This is the first time that FAR3d code was applied on EAST, so the model needed to be validated by reproducing the AE activity. The simulation results successfully identify the dominant mode, toroidal Alfven eigenmode (TAE), occurring at ρ=0.45 with a frequency of 87 kHz, toroidal and poloidal number n/m=2/3, 2/4. Additionally, a sub-dominant mode, energetic particle mode (EPM), is identified at ρ=0.55 with a frequency of 62 kHz, n/m=2/4. The agreement between the simulation and experimental results confirms the accuracy of the simulation model in characterizing the instability types, as well as providing consistent location and frequency information. Furthermore, the FAR3d code is employed to evaluate the influence of the finite Larmor radius (FLR) effect. The simulation results demonstrate that the FLR effect has minimal impact on identifying low toroidal mode number (n) instability modes in the high βN discharge of EAST. Consequently, the FLR effect can be neglected during the mode identification process, allowing for accelerated calculations. While, in the simulation of high toroidal mode number, the FLR effects should be considered. In conclusion, this study presents a comprehensive analysis of the Alfven instability in the high βN discharge of EAST. By combining experimental observations with simulation results, the types of instabilities, their locations, and frequencies are successfully identified and found to be in good agreement. Additionally, the study confirms that the FLR effect has little influence on identifying low n instability modes, enabling faster calculations by excluding FLR effects during mode identification. These findings contribute to a better understanding of the Alfven instability in high βN discharges and provide valuable insights for future research in fusion plasma physics.

The diffusion coefficient of oxygen in zirconium alloy oxide film and matrix is an important parameter in corrosion kinetics of zirconium alloys. At present, there are some reports on the diffusion coefficient of oxygen in zirconium and oxide film, but the numerical values in the literature are quite different. In this paper, zirconium alloy was corroded in pure water to obtain a sample with an oxide film thickness of 1 μm. Through vacuum annealing test, the oxygen concentration distribution of the oxide film at four different temperatures was obtained, the diffusion coefficient of oxygen in zirconium alloy matrix was calculated, and the Arrhenius relation of the diffusion coefficient in this temperature range was obtained by fitting. Compared with the literature data, the trend is similar, but the values are different. The main reasons may be the following two aspects:One is the measurement deviation of oxygen concentration distribution curve, including spatial position deviation and concentration error, and the other is the different grain size of samples. The diffusion coefficient of oxygen in zirconium metal without irradiation obtained in this work can be mutually verified with the literature data, which has high reliability. Based on the corrosion weight gain curves of two zirconium alloys at four different temperatures, the diffusion coefficient of oxygen in the zirconium alloy oxide film was estimated by the equivalent diffusion model of the oxide film and the corrosion weight gain curve before the corrosion transition. It is found that the diffusion coefficient of oxygen in the zirconium alloy oxide film increases obviously with the increase of temperature, and the diffusion speed of atoms is significantly affected by the microstructure of the diffusion medium except temperature. Based on the research of two parts, it is found that the diffusion coefficient of oxygen in the oxide film is greater than that in zirconium metal when the temperature is below 440℃, and the diffusion coefficient of oxygen in the oxide film is more than twice that in zirconium metal when the temperature is below 400℃, which shows that the diffusion of oxygen in the oxide film of zirconium alloy is main at the interface at lower temperature (440℃ in this paper), and further shows that grain boundaries, pores and microcracks in the oxide film play a very important role in the corrosion behavior of the alloy. The above research provides important calculation parameters and basic research theory for the corrosion kinetic model of zirconium alloy. The results show that the diffusion coefficient of oxygen in Zr-Sn-Nb matrix follows a relationship as DZr(cm2/s)=0.18·exp(-180 000/RT). The diffusion coefficient of oxygen in oxide film, which follows a relationship as Dox(cm2/s)=3×10-7exp(-101 550/RT), is also evaluated by the weight gain profile in pre-transition stage.

The monolithic scintillation crystal detector has the ability to position the three-dimension interaction location of the gamma ray in the detector depending on accurate acquisition of scintillation light distribution. Depth estimation of light field can be solved by a lens array in light field technology. A new detector model was designed in the paper which introduced a lens array for positioning the interaction in the monolithic detector. The scintillation light is focused by each lens unit in the lens array. Photons in some discrete pixels of the photon counter array where the scintillation light is focus on are detected to form an image of multiple focus points instead of the scintillation light distribution detection based on continuous crystal. The position of the scintillation light source in the crystal can be reconstructed from the focus image through optical path inversion. The detector model consisting of a monolithic crystal, a lens array and a multi-pixel photon counter was established in the paper. The monolithic scintillator was a lutetium-yttrium silicate (LYSO) scintillator with dimensions 48 mm×48 mm×45 mm. The lens was hemispherical with a radius of 15 mm supposed to be uniformly distributed in 3×3 array and the material was as same as the crystal. The crystal and the lens array were considered as a whole in the simulation. The multi-pixel photon counter was set at 44.4 mm from the crystal surface. The pixel size of the photon counter array was 3 mm and the quantum efficiency was 30%. The axis of symmetry of the three parts was same. The reconstruction algorithm was based on optical path inversion from multiple focus points for locating the 3D position of gamma-ray interaction. The intersection points of the inverted optical paths and the set z plane with different depths in the crystal was calculated in the reconstruction process. When the intersection points converged towards the same point in the z0 plane, the depth of interaction was z0 and the intersection point in the z0 plane was the interaction point. The reconstruction results were analyzed to evaluate the performance of the monolithic scintillation crystal detector based on the lens array. The x/y resolution is better than 1.54 mm and the z resolution is better than 3.13 mm. The two interaction points when coincidence occurs are reconstruced in the condition that the energy is the same. The detector is feasible for the positioning of two interaction points by the reconstruction results of three groups of selected positions. The monolithic scintillation detector based on a lens array has both good positioning ability and position resolution. The detector is suitable for the position reconstruction of multiple interaction points.

Existing studies have clearly demonstrated that people eating more whole grains have reduced risks of many chronic metabolic diseases compared to those eating less. In the past 20 years, the whole grain industry has developed so rapidly in major developed countries and regions. In recent years, whole grains have also attracted extensive attention in our country. The research and development efforts of the whole grain standards in China have been strengthened. This paper introduced the progress of the global definition consensus of whole grain and whole grain food, summarized the international development status of whole grain raw materials and whole grain food related standards in many countries and institutions, such as the Working Group of ISO Whole Grain, the United States, Canada, the Netherlands, Codex Alimentarius Commission, and so on. This paper also reviewed the present situation of definition of the whole grain and whole grain food related standards in China. More than 20 relevant raw materials, food related standards and production technical regulations and the publishment situation of other whole grain standards in China, including national standards and industry standards and local standards and group standards, were summarized, and some whole grain related standards under formulation were also introduced. Finally, the paper puts forward the development direction and suggestions for the construction of whole grain standard system in China, including fully combining with the actual production situation of China’s whole grain food industry, integrating with international standards, and combining standard testing and certification. On the whole, the gradual improvement of the standard system of the whole grain food industry will help guide and regulate the high-quality and healthy development of the whole grain industry in China, and promote the creation of a diversified and healthy grain food ecology, and provide a technical basis for the development of the whole grain industry.

The probabilistic safety assessment of nuclear containment under internal pressure is the key evaluation content for guaranteeing nuclear power plant safety, and the fragility assessment of the containment under internal pressure is the most crucial step in the probabilistic safety assessment of nuclear containment. At present, the internal pressure fragility assessment of the containment mostly adopts the simplified lognormal distribution model, which lacks a rigorous theoretical analysis. There are multiple uncertainty issues affecting structural responses of nuclear containment in the fragility analysis and the results of the fragility analysis should be on the basis of a rigorous capacity-demand model. Meanwhile, load parameters (i.e. internal pressure) are usually used as key information to assess the internal pressure failure probability of containment. However, damage and failure of containment are more intensively correlated to structural response parameters (e.g. structural acceleration, structural displacement, and damage indices) compared with load parameters. For this reason, this paper proposed an internal pressure fragility assessment method based on Bayesian theory for nuclear containment and a form of damage ratio was used as a parameter for fragility assessment of containment. The damage ratio was realized by defining the ratio of the damage area to the full area of the containment concrete. Specifically, the fragility assessment method first established a deterministic demand model for the containment under internal pressure, and then corrected the demand model by adding correction terms. After that, Bayesian estimation was used to gradually filter the correction terms, resulting in an accurate probabilistic demand model. Finally, a fragility assessment result was obtained by establishing a limit state equation for the containment. On this basis, the probabilistic model under internal pressure was introduced to realize the probabilistic safety assessment of the containment, and the results of probabilistic safety assessment were compared with those of conventional fragility assessment. The results show that the cumulative containment failure probability (CCFP) of the containment decreases gradually with the increase of the damage ratio and the coefficient of variation of the CCFP is obviously smaller than that of the conventional fragility assessment method. In this paper, Bayesian estimation is introduced for probabilistic safety assessment of internal pressure in containment, and the damage ratio is used as a key parameter for fragility assessment of containment, which can provide more accurate and conservative results for probabilistic safety assessment of internal pressure in containment.

While artificial intelligence has achieved considerable maturity in lung nodule detection, research on growth prediction remains limited. Accurate growth prediction aids clinical decision-making, informing patient follow-up strategies. This paper proposes a novel nodule growth prediction network model that generates high-quality lung nodule images at specific time intervals. The model employs a two-branch structure for feature extraction. One branch, leveraging a displacement field prediction mechanism, models the shape transformation of pulmonary nodules through voxel-level future displacement estimation. The other branch, empowered by a three-dimensional U-Net, focused on learning texture changes within the nodules. A coordinate attention mechanism that emphasizes informative features within the extracted high-dimensional feature map. Subsequently, the outputs of both branches are fused and fed into the feature reconstruction module to generate the final lung nodule growth prediction image. Furthermore, a time interval coding module is introduced to incorporate the desired time interval into the network, enabling the generation of prediction images for different future time points.

The physical properties of carbonate rocks play a crucial role in the exploration and development of oil and gas. Carbonate rocks are characterized by multiple types of porosity, and the complex porosity types result in a highly discrete relationship between porosity and elastic parameters. In this paper, a method based on rock physics models for substituting the physical property parameters of carbonate rocks is proposed. Initially, rock physics modeling is conducted on carbonate rock reservoirs, and inversion of the equivalent pore aspect ratio in the model is performed. During the substitution, all other parameters are kept constant, and only one of the porosity, calcite content, water saturation, or volumetric fraction of pore shapes is changed. In combination with amplitude versus offset (AVO) theory, forward modeling simulations are performed. The simulations reveal that the impacts of changes in porosity and pore shapes on seismic response are more significant, far exceeding the influences of variations in calcite content and water saturation, which have a weaker effect on seismic response. Application of actual data demonstrates that the method for substituting the physical property parameters of carbonate rocks proposed in this article can effectively analyze the impact of changes in physical property parameters and pore shapes, characterize the physical properties of rocks, and determine the types of rock porosity.

The need for school counselor intervention is crucial for victims of bullying. However, fews studies focus on guidance strategies used by school counselors. The present study aims to explore the frequency and perceived effectiveness of various guidance strategies from the perspective of school counselors. A total of 164 school counselors from northern, central, southern, and eastern Taiwan participated in the study by completing the paper surveys, while 53 school counselors completed online surveys. The results of multidimensional Rasch analysis identified: seven common and effective strategies, including learning to seek help, using body language, expressing thoughts and feelings, discussing problems, and recognizing and accepting emotions; five common yet ineffective strategies, including understanding the impact of bullying, practicing communication skills, maintaining physical boundaries, saying “no” to bullies, and focusing on the present; seven rare but effective strategies, including understanding definition and causes of bullying, empathic listening, staying calm, speaking assertively, recognizing behavioral pattern, and progressive muscle relaxation; six rare and ineffective strategies, such as identifying types of bullying, maintaining suitable posture, setting counseling goals, strategizng against bullying, exploring new approaches to handling bullying, and cognitive regulation. These results contribute to the evaluation of the effectiveness of different guidance strategies. For practical application, it is recommended that councelors remain conscious of their intentions and actions, tailoring their approach based on the needs of the victim. Counselors can refer to the results of this research to adapt and apply various strategies flexibly.

In recent years, heavy ion accelerator technology has been rapidly developing worldwide and widely applied in the fields of space radiation simulation and particle therapy. Usually, a very high uniformity in the irradiation area is required for the extracted ion beams, which is crucial because it directly affects the experimental precision and therapeutic effect. Specifically, ultra-large-area and high-uniformity scanning are crucial requirements for spacecraft radiation effects assessment and serve as core specification for beamline terminal design. In the 300 MeV proton and heavy ion accelerator complex at the Space Environment Simulation and Research Infrastructure (SESRI), proton and heavy ion beams will be accelerated and ultimately delivered to three irradiation terminals. In order to achieve the required large irradiation area of 320 mm×320 mm, horizontal and vertical scanning magnets are used in the extraction beam line. However, considering the various requirements for beam species and energies, the tracking accuracy of power supplies (PSs), the eddy current effect of scanning magnets, and the fluctuation of ion bunch structure will reduce the irradiation uniformity. To mitigate these effects, a beam uniformity optimization method based on the measured beam distribution was proposed and applied in the accelerator complex at SESRI. In the experiment, the uniformity is successfully optimized from 75% to over 90% after five iterations of adjustment to the PS waveforms. In this paper, the method and experimental results were introduced.

Subcooled flow boiling contains complex bubble behaviors and interactions. Accurate prediction and analysis of the subcooled flow boiling are of great significance for the safe operation and economy of the nuclear reactors. The bubble-layer-based model is a new theoretical model in predicting the flow boiling, which divides the flow filed into two regions in the radial direction, which are the bubble layer region and the core region. Bubble behaviors in each region, mass and energy exchanges between different regions, and variations of parameters in the axial direction are analyzed and reflected through a set of two-dimensional steady-state conservation equations of mass, momentum and energy. Therefore, this model can provide more detailed information of the flow field than current one-dimensional models. However, this bubble-layer-based model for the subcooled flow boiling has only been verified in conventional tubes. When the channel type and sizes change, the accuracy of the model is still uncertain. Considering that rectangular channels are widely encountered in multiphase flow equipment, this paper aims to further extend this model to the prediction of the subcooled flow boiling in rectangular channels. Firstly, several flow boiling experiments in both conventional rectangular channels and narrow rectangular channels were selected. The working conditions are 0.1-8 MPa for pressure, 211-1 700 kW/m2 for heat flux, 240-2 200 kg/(m2·s) for mass flux, 4.42×103-3.72×105 for liquid Reynold number and 0.83-1.76 for Prandtl number. Then, variations of void fraction obtained by this model were compared with these experimental data. The results show that this bubble-layer-based model shows high accuracy when it is applied to both conventional rectangular channels and narrow rectangular channels, which reflects that the channel size and shapes have limited impact on the accuracy of this model. In addition, to further verify the accuracy of this model, one of the existing models (Cai model) in predicting the void fraction in subcooled flow boiling was also selected for comparison. The results show that the bubble-layer-based model shows higher accuracy than Cai model, with the relative error of 32.7% and 52.6% respectively. Finally, this model was applied to the analysis of the flow boiling in one narrow rectangular channel. It describes the variations of several two-phase flow parameters, such as the void fraction, pressure, velocity and temperature. These results not only provide a better understanding of the mechanism of subcooled flow boiling, but also provide basic data for the thermal physical coupling analysis of the rectangular fuel elements in nuclear reactors.

The spacer grid models are important models for simulating the thermal-hydraulics phenomena during reflooding process. The spacer grid pressure drop model, wall heat transfer enhancement model, interfacial heat transfer enhancement model, droplet breakup model, spacer grid re-wet model and grid temperature model are integrated in COSINE multiphase sub-channel code. In this paper, the typical rod bundle heat transfer (RBHT) reflooding tests were selected to assess the spacer grid model in the code. The calculation results show that the spacer grid models can significantly enhance the code predicted heat transfer capacity, accelerate the quench rate and reduce the peak cladding temperature (PCT) during the reflooding process, and the calculated results are in good agreement with the experimental measurements. In addition, the deviation of the PCT predicted by the code is reduced from 10% to 7% due to the adoption of the spacer grid models. The spacer grid models have the ability to enhance the interfacial heat transfer between vapor and droplet, therefore the calculated results with the spacer grid models show a significantly faster decrease in vapor temperature than that without the spacer grid models. And the calculated vapor temperatures with spacer grid models are in good agreement with the experimental measurements. The trend of the code predicted spacer grid temperature agrees well with the experimental results, but the code predicted spacer grid temperature is slightly higher than the experimental measurements. Furthermore, the early wetting of the temperature probe located on the spacer grid in the experiment results in a rapid decrease in the spacer grid temperature, however，the code predicted spacer grid temperature does not show as sharp a decrease as the experimental results due to the interpolation method in the calculation of the spacer grid temperature. The spacer grid models adopted in the code can simulate the breakup of droplets across the spacer grid, the diameter ratio of the shattered droplets predicted by the code is in good agreement with the experimental measurements, and the calculation results of the Cheung model are more accurate than those of the Paik model in the test case 7151. In addition to this, the code can predict the trend of droplet velocity near the spacer grid during reflooding process, but the calculated droplet velocity decreases significantly faster than the experimental measurements, and it needs more work in future. In general, the calculated results with the spacer grid models are in good agreement with the experimental results, and the spacer grid models adopted in the code are reasonable and reliable.

Containment cooling capability verification test (COCOVET) is conducted to confirm air baffle removal code for passive nuclear power plant. The shrink ratio of passive containment cooling system (PCS) air passage between the test body and the prototype is 1∶4. In the COCOVET air convection heat transfer test, the flow around and separation of air at the tail end of the baffle are observed within the operating parameters of the PCS system, and the test working condition matrix is determined within the parameter range to study the mixed convective heat transfer characteristics of air and the containment wall. COCOVET air cooling test conditions were selected in this paper, and particle image velocimetry (PIV) was used to visualize the air flow in the containment annulus. By comparing the test data and code simulation results, the mixed convection heat transfer phenomenon of forced and natural air convection coexisting in the containment annulus was studied, the applicability of the safety analysis code of the containment was verified, the response of the containment after the accident was simulated, the cooling capacity of the containment was evaluated, and the feasibility of the optimization scheme of the baffle was demonstrated. The research results show that after the air reaches the tail area of the air baffle, most of the air in the descending section of the containment annulus enters the rising section 180° and flows upward along the baffle, while a small amount of air continues to flow downward along the cooling surface. In the area without baffle, the heat transfer mode of heating surface is mainly natural convection type, and the heat flux of heating surface is basically unchanged along the height direction. In the area with baffle, there is an obvious inlet effect in the rising section of the containment annulus, and the heat flux on the heating surface increases rapidly and then decreases. By using the lumped parameter and three-dimensional parameter modeling method and the mixed convective heat transfer empirical equation, the calculated values of the safety analysis code of the containment are in good agreement with the experimental values, which is suitable for simulating the mixed air convective heat transfer process. The containment pressure response analysis of the optimal scheme of the air baffle shows that the peak pressure of the containment is less than the design pressure of the containment and has a certain margin, which meets the requirements of the safety analysis of the containment. The research results verify the feasibility of the optimization scheme of the baffle in passive nuclear power plants, and enrich the research content of air mixed convection heat transfer.

During a postulated accident in water-cooled nuclear reactors, such as loss-of-coolant accident, the reactor core can be partially or completely uncovered from coolant and consequently becomes overheated. The cold liquid is reinjected into the nuclear reactor core to effectively cool the superheated fuel rods. In this process, the quenching boiling will be encountered in the fuel rod surface. The reflooding quenching boiling of nuclear fuel rod is an important accident mitigation measure to avoid the core melting after the loss-of-coolant accident of the core of pressurized water reactor. In this work, quenching experiments of Zr-4 alloy with different roughness were performed in subcooled distilled water pool at atmospheric pressure. The surface of Zr-4 was polished by abrasive paper with different mesh numbers. The effects of Zr-4 surface roughness and coolant subcooling degree on cooling rate and boiling heat transfer during the quenching boiling were studied. The visualization experiments of quenching boiling were carried out on different surface roughness test sections, and the internal temperatures of test sections were measured at the same time. The image processing technique was used to obtain the evolution of vapor film thickness during quenching boiling of fuel rod and the inverse heat conduction problem was employed to obtain the surface temperature and heat flux during the quenching. The experimental results show that the surface roughness has little effect on the film boiling heat transfer. However, the surface with higher roughness triggers the surface-liquid contact earlier and strengthens the quenching boiling. When the roughness is small, the effect of roughness on quenching boiling is weak. When the roughness is further reduced, the duration of quenching boiling increases due to the increase of the surface contact angle. In addition, with the increase of the liquid subcooling, the vapor thickness of film boiling decreases, the minimum film boiling temperature to maintain stable vapor film increases, and the quenching rate increases. Based on the experimental data, the relationship between the minimum film boiling temperature (Tmin) and the coolant subcooling degree (Tsub) is established with the average error of 2.4%. This study provides a theoretical basis for the boiling heat transfer mechanism during the reflooding process of nuclear reactor core at a loss-of-coolant accident.

In the event of core disassembly accident (CDA) in a sodium-cooled fast reactor (SFR), the molten material from the core migrates and interacts with the low-temperature coolant in the lower plenum, resulting in the formation of core debris that eventually settles to forms a debris bed. Improper placement and inadequate cooling of the debris bed can result in the failure of the pressure vessel. To efficiently disperse the core debris and minimize contact between the lower head of the pressure vessel and the molten material, a core catcher was specifically designed as a passive preventive and mitigating device. The structure of the core catcher directly impacts the shape and distribution of the debris bed, which subsequently affects its re-criticality and long-term decay heat removal capability. This study aims to perform a numerical investigation to optimize the structural design of the core catcher, with a specific focus on the mechanisms and laws of the chimney structure of the core catcher on the formation and distribution of the debris bed. The improved discrete element method (DEM), which is based on dimensionless stiffness and dimensionless damping coefficients, was employed to numerically simulate the formation process of the debris bed on the core catcher. This method incorporates source terms into the momentum equation of debris particles to account for the influence of coolant on their motion. Validation experiments were conducted to verify the capability of the numerical simulation algorithm used in optimizing the design of the core catcher. In this paper, the effects of three factors on particle motion and debris bed formation mechanisms were investigated by varying the vertical projection side length of the chimney cover, inclination angle of the cover, and spacing between chimneys. The research findings suggest that the selection of appropriate values for these parameters has a substantial impact on the shape and distribution of the debris bed. Therefore, it is recommended to establish reasonable chimney design parameters to achieve optimal performance in practical applications. Furthermore, this study reveals that during the formation of the debris bed, the debris particles demonstrate a secondary scattering effect, which plays a vital role in enhancing the uniformity of the debris bed. This study will provide valuable engineering references for optimizing the design of the core catcher.

Miniaturization of nuclear energy systems will be a promising direction for nuclear industry development in the future, in which micro lead-cooled fast reactors (LFRs) are a type of technical route in relevant. During the R&D of micro LFRs, transient thermal-hydraulic safety analysis is one of the important research fields, which can not only verify the safety of the design, but also provide optimization reference for the follow-up design of the reactor. SMILE is a megawatt-level micro LFR with high safety and compactness, designed by State Power Investment Corporation Research Institute. For SMILE, pure lead is applied as the coolant. The fuel adopts UO2, while the cladding and structural materials use independently developed wide oxygen-controlling corrosion-resistant materials, which can simplify or even omit complex oxygen measurement and control systems. Its core is designed for long-life without refueling, eliminating complex refueling devices. Its reactivity is controlled by external drums. The main system employs a compact design scheme, using a pool-type integrated compact layout, with an integrated main pump and main heat exchanger structure. The secondary system uses a compact water steam cycle or S-CO2 Brayton cycle, along with a non-passive residual heat removal system. Due to the advanced concepts of lead-cooled fast reactor designs, there has not been a mature unified thermal-hydraulic safety criterion. Based on SMILE’s design characteristics and a literature review, some key parameters’ performance criteria for thermal-hydraulic safety are proposed, including flow velocity of the coolant, coolant temperature, temperature of the fuel cladding, etc. During reactor operation, various abnormal events deviating from normal operating ranges may occur, potentially leading to accident conditions. For SMILE, unprotected loss of flow (ULOF), unprotected transient over-power (UTOP), unprotected loss of heat sink (ULOHS), were deeply investigated in the present paper. ATHLET (analysis of thermal-hydraulics of leaks and transients) is a best-estimate one-dimensional system safety analysis program developed by Gesellschaft für Anlagen-und Reaktorsicherheit (GRS), which is applicable to analyzing various reactor types such as pressurized water reactors, boiling water reactors, graphite-water-cooled reactors, and CANDU reactors, for both benchmark and beyond-benchmark accident analyses. With the development of Gen-Ⅳ nuclear energy systems, GRS has extended the applicability of ATHLET, incorporating properties of metals and liquid metal heat transfer relationships, enabling to be applied for analyzing the thermal-hydraulic characteristics of lead-cooled fast reactors. Through analysis, it is found that under normal conditions, the results obtained from ATHLET are in good agreement with the design values, thus AHTLET program is capable of analyzing the transient features of SMILE. Under typical unprotected transient accident conditions, SMILE shows a good natural circulation performance and thermal characteristics, in particular given it inherent safety features. However, according to simulation results, in the event of an ULOF transient accident, the cladding temperature of the fuel exceeds the maximum temperature limit, which could potentially threaten the reactor’s safe operation. Therefore, in the future high-temperature corrosion-resistant materials will be developed, for eliminating or mitigating its impact on the system’s safe operation.

Division 5 of the ASME code section Ⅲ (referred to as ASME-Ⅲ-5) provides design-by-analysis methods and evaluation criteria for Class 1 nuclear components working at high temperatures. It has a long history and is the main international design code for high temperature nuclear equipment. It took the lead in adopting the idea of stress classification and first introduced the concepts of primary stress, secondary stress and peak stress, which had a far-reaching impact on the development of subsequent other high temperature design codes. However, with the rapid development of computational methods, high-performance computer technology, commercial finite element software and high temperature inelastic analysis methods, the results derived from elastic analysis and the evaluation of stress classification used by ASME as a mainstream method exist the limitation of overly conservatism and thus insufficient design economy. This paper first introduced the definition of high temperature condition and the insignificant creep temperature, as well as the design loads, failure mechanisms, design-by-analysis methods, and evaluation criteria of ASME code for nuclear Class 1 components at high temperature. Then, by comparing the analysis methods and criteria of primary load limit and deformation control limit of ASME with other high temperature codes, such as R5, RCC-MRx and MONJU (with or without consideration of the time dependence of creep), the advantages and limitations of ASME analysis methods and criteria were explored. Each code has its distinct characteristic. British R5 code focuses on the reference stress method and the application of limit analysis. French RCC-MRx code is in the same lineage with ASME, but distinguishes between significant/insignificant creep and significant/insignificant irradiation effects. Japanese MONJU code distinguishes the long-term load from short-term load, such as seismic load. Long-term loads and short-term loads adopt different limits to avoid overly conservatism. It is concluded that the elastic analysis based on the stress classification traditionally adopted by the ASME code is excellent, but it cannot perfectly cope with the all the code-considered failure mechanisms due to its inherent characteristics. Therefore, several methods are proposed as alternative methods for the ASME-Ⅲ-5 improvement. The pointed-out directing improvement aspects of ASME-Ⅲ-5 enable to enhance the advancement, economy and safety of the development and use of ASME, with the scientific integration of the traditional design of pressure vessels and the new era of computational analysis technology. At the same time, this study also has important guiding value for the development and construction of Chinese independent design code in nuclear Class 1 high temperature pressure-bearing components.

By dispersing the fuel particles in an inert metal matrix, the dispersion nuclear fuel element has the advantages of high burnup, high thermal conductivity, great safety and strong designability, etc. It has been successfully applied in the test reactors. Within a dispersion nuclear fuel element, the failure of fuel meat is significantly influenced by the particle agglomeration behavior, including the agglomeration extent, the location of agglomeration region, fuel particle spacing, etc. The present study investigates the crucial factors influencing the failure behavior in the dispersion nuclear fuel meat, focusing on the particle agglomeration effect on the failure of fuel meat. By developing a script for parametric modeling and numerical calculations of the representative volume element in the dispersion nuclear fuel element, the Mises stress field of dispersion nuclear fuel meat incorporating with different particle agglomeration characteristics was simulated in this paper. Numerical modeling was performed by considering the damage layer at the fuel-matrix interface, irradiation-induced fuel particles swelling and the environmental pressure outside the cladding. The effects of particle agglomeration volume fraction, location of the agglomerate fuel particles, ambient hydro-static pressure and matrix material properties on the failure of dispersion nuclear fuel meat were analyzed systematically. The fuel particles in agglomeration region were geometrically modeled through dense stacking, while the local particle agglomeration volume fraction was defined by the minimum particle spacing. The results show that the failure behavior in dispersion nuclear fuel meat is enhanced with the increasing of particle agglomeration volume fraction. The environmental pressure outside the cladding can inhibit the stress concentration in the dispersion fuel meat, but this influence declines with the extent of local fuel agglomeration increasing. Furthermore, the particle agglomeration location between the upper and lower cladding layers of the thin plate indicates little effect on the maximum Mises stress in the dispersion nuclear fuel meat. However, compared to the dispersion meat adjacent to the surrounding cladding, fuel particles agglomerating in central meat (i.e. only constrained by the upper and lower cladding) are more sensitive to environmental pressure. The local fuel particle agglomeration has a shortest stave effect on the failure of dispersion nuclear fuel meat. The volume fraction of agglomeration will seriously exacerbate the stress concentration, and the agglomeration location in the interior of dispersion fuel meat will fail first. Therefore, it is concluded that the extent of fuel particle agglomeration, the location of agglomeration region within the dispersion nuclear fuel meat, and the environmental pressure are crucial factors influencing the failure behavior of fuel meat. The fuel particle agglomeration region is the onset location for the local macroscopic failure, and the environmental pressure outside the cladding can decrease the plastic stress concentration in the dispersion fuel meat to improve the safety of reactor core. This work provides an analytical approach and numerical reference for the failure condition prediction, the reliability evaluation, and the structural optimization design of the plate dispersion nuclear fuel element.

Limited by the characteristics of the boron neutron capture therapy (BNCT) treatment beam, it is difficult to measure the γ ray energy spectrum of the source term. There are few relevant work has been carried out. Up to now, only the γ energy spectrometer directly measured the source term γ rays, but the spectrometer was not been calibrated and unfold. In order to obtain an accurate γ energy spectrum of the source term, it is necessary to calibrate the γ energy spectrometer and establish the reliable response function of the system. This paper briefly introduces the γ energy spectrometer designed for BNCT treatment beam, and mainly introduces the calibration method suitable for this spectrometer. The spectrometer consists of a high purity germanium (HPGe) detector and a shield system. Since the entire spectrometer is designed for high intensity neutron/γ mixed fields, the shield effect of the spectrometer is so effective, and it is impossible to calibrate the γ response of the entire spectrometer system through experimental methods. By analyzing the spectrometer system, the dead layer distribution of the HPGe detector is the main influence factor, and other structures can be accurately obtained through X-ray radiography and geometric measurements. Therefore, the calibration method of the spectrometer is as follows: obtain an accurate model of the HPGe detector by X-ray radiography and calibration; use precision measurements, fine geometric measurement and material analysis to obtain an accurate model of the shield, and establish a calculation model of the spectrometer; acquire the response function of the spectrometer system through Monte Carlo N particle transport code (MCNP) calculation, and the energy spans from 0.1 MeV to 1 1 MeV with an energy interval of 10 keV. Among them, the HPGe detector dead layer distribution can be confirmed using the following steps. The efficiency of the HPGe detector was calibrated utilizing standard γ sources and high-energy γ reference radiation fields. The dead layer distribution of the HPGe detector was adjusted using MCNP to ensure agreement between calculated and measured efficiencies, thereby determining the geometric distribution of the dead layer. Therefore, using a combination of Monte Carlo simulation and experimental methods, the results can be traced to the corresponding national or national defense standards, ensuring the accuracy and reliability of the key parameters of the spectrometer, and laying the foundation for subsequent spectrum unfold work.

With a half-life of 7.2 h, the decay of 211At produces α particles that have a limited range in tissues (55-80 μm), equivalent to approximately 6-8 cell widths. Its LET value of 98.84 keV/μm is very close to the optimal LET value (100 keV/μm) for effective internal radiation therapy, exhibiting strong cytotoxicity. Consequently, 211At is considered the most suitable α emitting isotope for targeted internal radiation therapy. It is also used as an alternative internal radiation source for α irradiation studies involving extractants and similar substances, replacing long-lived nuclides such as 238/239Pu and 241Am. However, due to the limitations in 211At yield, the maximum irradiation dose is difficult to increase, imposing constraints on irradiation dosage. Hence, it becomes crucial to enhance the radiochemical separation yield of 211At, whether for tumor-targeted therapy or α irradiation investigations. The production of 211At is typically accomplished using a cyclotron through the 209Bi(α,2n)211At reaction. And the radiochemical separation techniques employed for purification 211At primarily involve wet and dry distillation methods. Nonetheless, the current dry distillation methods have certain drawbacks, including unstable yield and the requirement for physically stripping irradiated bismuth from the target substrate, which poses a risk of nuclide escape. To solve these issues, a dry distillation process for production of 211At with an integrated semi-automatic dry distillation separation equipment was designed and optimized in this paper. The main influencing factors on dry distillation separation were determined using iodine as a simulation for astatine due to their similar chemical character, and feasible steps for the 211At dry distillation separation process were improved. It is found that once the furnace temperature is capable of vaporizing the target product, the key factors influencing the dry distillation process revolve around carrier gas velocity, holding time, and vacuum conditions. The results of 211At dry distillation separation show that when the α beam intensity of accelerator is 20 μA, α energy is 28.5 MeV, and the Bi target is bombarded for 4 h, the 211At yield of separated by the equipment for single run can reach more than 17.87 mCi (6.61×108 Bq). The nuclear purity of the prepared 211At is more than 99.9%, and free of impurities such as Bi and Cu. The integrated semi-automatic equipment has a recovery rate of over 98% for 211At in a separation time of 45-60 min.

Air pollution is a global issue that threatens human health. In recent years, more and more studies have found that air pollution is closely related to the occurrence of depression. As a serious neuropsychiatric disorder whose incidence is rising rapidly year by year, depression has become an invisible killer of public health. At present, studies on the correlation between air pollution and depression are still very limited, and the underlying molecular mechanisms by which air pollution affects depression are not clear. Based on existing epidemiological and toxicological studies, this paper provided a review of the relationship between air pollution and depression and the possible biological mechanisms, with a focus on the relationship between air pollution and depression indicators and the possible factors affecting depression such as types of air pollutants, exposure time, age and health status of study subjects. In addition, the potential roles of neuroinflammation, oxidative stress, neurogenesis, and apoptosis in the process of air pollution-induced depression were also discussed in order to provide a scientific basis for the prevention and treatment of air pollution-induced depression.

Knowledge graph is an indispensable part of cognitive intelligence research.Aiming at the problem that the traditional analysis method of stope mine pressure hazard events has insufficient expression of the stress time and space evolution process and the relationship between hazard evolution and risk prevention and control in the coal mining process, this paper proposes a knowledge graph representation method that based on the entire life cycle of stope for mining pressure hazard events.Firstly, from the perspective of geological disasters, the dynamic characteristics of stress and distribution in stope were analyzed.The dynamic correlation of various nodes in mine pressure geological disasters was established, and a knowledge graph representation method for mine pressure geological disasters considering spatiotemporal processes was proposed.Secondly, from the perspective of accidents, the evolution of hazard and the process of risk prevention and control in mine pressure accidents were analyzed.The evolution of hazard and preventive measures were integrated into the knowledge graph representation model.Finally, Neo4j was used to build the knowledge graph of mine pressure hazard events.The results indicate that the knowledge graph constructed based on this representation method not only depicts the spatiotemporal evolution processes of different objects in disaster events but also describes the coupling evolution process of hazards and corresponding risk prevention and control measures.This provides an intelligent research pathway for the prevention and control of mining pressure hazards in intelligent mining.

Using aeolian sand(AS)for backfilling can realize local material extraction and turn waste into treasurethe, and realize coordination of green mining and AS control.The AS filling mining is mainly applied to the backfilling of goaf under Highway, backfilling mining of coal mine and metal mine.Grouting and sand injection in the goaf, solid backfilling mining, high water backfilling mining and cemented backfilling mining are developed.Long wall backfilling mining, strip backfilling mining and roadway backfilling mining are adopted.The research on the properties of cemented AS backfilling materials focused on slurry fluidity and backfill strength.In this paper, the rheological properties of cemented AS slurry with different proportions and curing times are analyzed, and cemented AS backfills are toughened by using polypropylene fiber.The results showed that the rheological parameters of cemented AS slurry increased with the curing time, and the addition of fiber significantly improved the brittleness characteristics of cemented AS backfills.

Mine filling and tunnel spraying projects pose high requirements on the rheological properties of cement-based materials.The types, conditions of fine sands and the exposed environment have significant effects on the rheological properties.In this light, this paper uses coal gangue sand instead of quartz sand as the fine aggregate of cement-based material and investigates the effect of temperature and aggregate prewetting on the rheological properties of mortar and its mechanism.Results show that the shear stress-shear rate relationship of coal gangue mortar conforms to the characteristics of Herschel-Bulkley(H-B)model, with higher rheological index(higher than 1)and higher consistency than that of quartz sand mortar.The apparent viscosity of coal gangue mortar decreases with increasing temperature, but the effect of aggregate prewetting is not significant.The yield stress of coal gangue mortar at 30 ℃ is 2.99 Pa, 1.45 times higher than that at 10 ℃, and 2.13 times higher after prewetting.The thixotropic ring area of coal gangue mortar is higher than that of quartz sand mortar, and the thixotropic ring area of pre-wetting coal gangue mortar is 398.4 Pa/s, while that of dry coal gangue mortar is 283.3 Pa/s.The obtained results are expected to provide evidence for the rational utilization of coal gangue sand and the design and preparation of rheological materials served in complex environment.

China's intelligent mine construction is still in the early stage of development, which is seriously constrained by data trust problems such as low credibility of mine data, lack of trust mechanism in the data sharing process and the risk of data security and privacy leakage.To this end, this paper proposes an intelligent mine data trust model by drawing on the holistic approach to national security.Specifically, this study 1) offered a working definition of this model and proposed its underlying conceptions; 2) designed its technical architecture and analyzed the core technologies involved; 3) proposed the implementation strategies of the intelligent mine data trust model based on blockchain technology.This may lay the foundation for blockchain technology to empower intelligent mines and comprehensively enhance its efficiency and productivity, thus promoting the high-quality development of the coal industry.

In the process of mariculture, a large number of toxic and harmful substances such as organic matter, ammonia, and nitrite are produced during the metabolism of cultured organisms and the decomposition of feed residuals. If such maricultural wastewater is discharged without purification treatment, it will aggravate the occurrence of eutrophication in the receiving sea area. Constructed wetlands (CW) have received widespread attention due to their low operating costs, simple maintenance, and management advantages. Using CW to treat maricultural wastewater has great prospects. Nitrogen removal is one of the main tasks of constructed wetlands. The characteristics of high salinity and low C/N of maricultural wastewater result in the unique treatment environment and operating mechanism of CW. The substrate can adsorb nitrogen in the constructed wetlands, and nitrogen-cycling microorganisms such as nitrifying bacteria and denitrifying bacteria can attach to the surface to form biofilms. The selection of suitable substrate materials, in addition to zeolite, cinder, sand, and other commonly used water purification materials, can strengthen water purification. Given the low C/N characteristics of maricultural wastewater, materials with slow-release carbon sources can be selected as the filling substrate of constructed marine wetlands. For example, biological carbon sources such as corncob and wood chips, and polymer materials such as PCL and PLC, have recently been used as substrates to fill constructed wetlands and release carbon sources. Meanwhile, substrates that can drive the autotrophic denitrification process of microorganisms such as sulfur autotrophic, hydrogen autotrophic, and iron autotrophic have also been used as a solution. Plants are an important component of constructed marine wetlands, supporting nitrogen removal in four aspects: Nitrogen absorption, oxygen transport, carbon source secretion, and root enrichment of microorganisms. The high salinity environment determines that the wetland plants should be salt-tolerant, and the screening of salt-tolerant plants is a key step in constructed marine wetlands. Currently, Spartina alterniflora, Suaeda salsa, Salicornia bigelovii, Kandelia candel, and similar plants are chosen as candidate plants for constructed marine wetlands. The selection of plants should also consider local conditions, choosing salt-tolerant plants suitable for growing in the local environment. The nitrogen cycle of microorganisms is the main path of biological nitrogen removal in CWs. Various nitrogen-metabolizing bacteria cooperate and restrict each other in CWs, including autotrophic and heterotrophic bacteria, as well as aerobic and anaerobic bacteria. In the process of nitrogen removal in constructed wetlands, dissolved oxygen (DO) is an important environmental factor affecting the distribution and functioning of nitrogen-removing microorganisms. The relatively high DO in the upper layer of the constructed wetland favors the growth and reproduction of aerobic microorganisms, promoting the traditional nitrification process dominated by AOA, AOB, and NOB. The relatively low DO in the bottom layer is more conducive to the growth and colonization of anoxic and anaerobic microorganisms, favoring anaerobic denitrification, Anammox, and DNRA. The occurrence of Comammox can be driven under low nutrient and low oxygen conditions. These bacteria with nitrogen metabolism functions are distributed in different areas, cooperating and restricting each other, forming a complex nitrogen cycle network. Clarifying the basic path of the nitrogen cycle in seawater constructed wetlands is the fundamental basis for regulating the operating parameters of constructed wetlands. The low C/N of mariculture wastewater is not favorable for denitrification by microorganisms. Carbon sources can be supplemented with additional liquid carbon sources, solid carbon sources, and plant litter. DO is the key control index of constructed marine wetlands. The dissolved oxygen content in constructed wetlands is significantly correlated with the community composition of denitrification microorganisms. Therefore, oxygen supply regulation modes, such as continuous aeration, intermittent aeration, and tidal flow, may be effective measures for mariculture wastewater constructed wetlands to improve the overall nitrogen removal performance of wetlands. Accurate regulation of the oxygen supply mode and oxygen supply in constructed wetlands and optimization of dissolved oxygen distribution in different times and spaces within the system are the development trends of nitrogen removal technology in constructed wetlands in the future. The hydraulic operation conditions of CW play an important role in its nitrogen removal effect. Too high or too low indices will affect the efficiency of nitrogen removal in wetlands. Therefore, the optimal control values of hydraulic retention time (HRT), hydraulic loading rate (HLR), and other hydraulic parameters of constructed wetlands also need to be studied. The hydraulic conditions of constructed wetlands also have a significant impact on plant growth, affecting the purification efficiency of plants. In this paper, recent research progress and perspectives on constructed wetlands for the purification of maricultural wastewater and its biological nitrogen removal process were reviewed from four aspects: Selection of substrate, screening of salt-tolerant plants, nitrogen cycling microorganisms, and operation regulation. It is expected to provide a theoretical basis and support for regulating the actual operation of maricultural wastewater constructed wetlands and improving the technical level of maricultural wastewater treatment.

針對國民教育的教科書內涵及選用，強調素養導向的十二年國民基本教育核心理念已有調整，加上COVID-19疫情肆虐，教師選書模式的改變值得關注。本研究以國語教科書為例進行實證調查，探討疫情下教師選書之影響因素。研究以國小教師為對象進行問卷調查，獲得1,264份有效問卷。經分析發現，教師選書的主觀規範及選用規準的五種屬性對其決策皆有影響；教師選書主觀規範對發行屬性有正向影響、對內容屬性呈現更嚴格的檢核標準，顯見主觀規範影響愈大，對選書決策內容屬性要求愈高；另社群媒體平臺在發行屬性和選書決策間具有調節效果。依結果推論，傳統的選書程序因防疫而有新的變革，社群媒體平臺的使用可增加教師對教科書的瞭解、吸收教科書相關訊息，並提高選書決策信心。 Purpose Allowing teachers to select their own textbooks promotes the diversification, specialization, and democratization of education, encourages publishers to develop higher-quality materials, and enables teachers to select the materials that best meet their instructional needs. A policy of allowing instructors to choose their textbooks strengthens teachers’ professional growth and enhances the quality of education they provide. Numerous studies have identified the features that influence textbook selection, including policies and writing processes, evaluation criteria, visual design, content compilation, psychological factors, and disciplinary conceptual frameworks. However, the practices traditionally used to select standardized textbooks for national education have been subject to challenges and criticism owing to politically motivated changes in the content and selection of textbooks approved by Taiwan's Ministry of Education, the emphasis on a competency-oriented core in the compulsory 12-Year Basic Education, and the disruption caused by the COVID-19 pandemic. Physical book selection and public briefings have been replaced by the online interactive texts and noncontact instructional modes required by the pandemic. Research on the factors influencing teachers when selecting their textbooks is lacking. The present study sought to address this critical research gap by examining the textbook selection criteria of elementary school Mandarin Chinese teachers. Methodology This study adopted a quantitative survey method. First, a literature review examined textbook selection practices to clarify how textbooks have historically been selected in terms of policies, institutional practices, and criteria. Second, studies were reviewed, and items were selected to develop a survey instrument. Third, six experts and scholars in textbooks, education, questionnaire design, and educational administration were invited to review and revise the questionnaire’s content and wording, thus ensuring expert inter-rater validity. This evaluation process resulted in a preliminary questionnaire titled “Questionnaire on Factors Influencing the Selection of Mandarin Chinese Textbooks in Elementary Schools,” which consisted of items in nine dimensions: environmental factors, textbook selection factors, teaching factors, content factors, physical factors, distribution factors, skill factors, social media factors, and usage factors. Fourth, the preliminary questionnaire was distributed to 129 participants for pilot testing, and item analysis and construct validity were examined. This process resulted in a formal questionnaire comprising 48 items. Fifth, convenience sampling was used to invite Taiwanese elementary school Mandarin teachers to participate; 1,264 valid responses were obtained. Sixth, descriptive statistics were used to understand the sample characteristics and the influence of the research factors. Seventh, confirmatory factor analysis was conducted using structural equation modeling. Finally, hierarchical regression analysis was employed to test the research hypotheses. Findings The reliability and validity of the questionnaire were examined using the data collected from the formal survey. Confirmatory factor analysis was conducted to test each item’s standardized factor loading estimates, which were all greater than 0.500, indicating acceptable reliability. An assessment of convergent validity indicated the favorable convergent validity of the scale, and the results also confirmed the discriminant validity of the instrument through significant factor loadings. Subsequent regression analysis revealed that environmental factors significantly influenced five groups of factors in the textbook selection criteria: teaching, content, physical, distribution, and skill factors. These results indicated that the COVID-19 pandemic substantially affected teachers’ textbook selection criteria. Selection factors were positively associated with content factors and distribution factors. This result suggested that both content and availability strongly influenced selection factors. Regarding selection criteria, three types of factors— content, physical, and distribution factors—were positively associated with selection factors. This result indicated that content, availability in nonphysical editions, and distribution influenced the teachers’ textbook selection decisions. Additionally, social media factors were found to have a significant moderating effect between distribution factors and selection factors. This finding suggested that when distribution factors were favorably reviewed in social media factors, teachers were more confident in their selection decisions. The results of this study’s analysis revealed that the content factors of the 108 Curriculum heavily influenced teachers’ textbook selection decisions, whereas skill factors did not. One reason skill factors may not have influenced textbook selection is that teachers trust that the 108 Curriculum textbooks align with the standards mandated by Taiwan’s Ministry of Education and that these textbooks are composed by experts in their fields. However, environmental factors during the pandemic strongly affected selection factors. Teachers considered online information a vital tool in making selection decisions when the pandemic prevented them from traveling to bookshops. Moreover, environmental factors were positively associated with all five dimensions of the selection criteria. Physical factors and distribution factors were positively associated with selection factors, suggesting that teachers prioritized readability in layout, font size, correspondence between text and illustrations, color arrangement, glare-free paper quality, and binding quality. Additionally, teachers who relied on social media platforms felt more confident in the quality of the textbooks they selected, whether they were available online, as physical copies only, or both. Social media platforms, including Line and Facebook, significantly influenced textbook selection decisions during the COVID-19 pandemic beyond merely increasing teachers’ confidence in their choices. Originality/Value This study provides empirical research on the factors influencing textbook selection during the COVID-19 pandemic. The research sample consisted of elementary school teachers throughout Taiwan, ensuring the study’s objectivity and specificity. This study proposes textbook selection factors and decision-making patterns distinct from those found in marketing and procurement decision-making models in business contexts. The differences have arisen from the unique needs of Taiwan’s elementary school Mandarin Chinese teachers, which differ substantially from those of teachers in previous studies on textbook selection.

青銀世代對數位遊戲的使用動機具差異性，而數位遊戲的開發或設計往往無法為所有年齡層量身定做，例如長者對於規則太複雜、時間太緊湊的遊戲設計有負面的認知，但年輕人反而追求遊戲的效率。此外，過去探討不同世代數位遊戲設計及功能評估的研究，大多為受試者自陳、觀察和訪談方法蒐集主動意識層面的資料，較少透過語意聯想這類的結果探究。 據此，本研究欲以數位遊戲認知的語意聯想測驗（Word Association Test, WAT）蒐集多元的資料以探討世代間之異同。本研究以便利取樣招募178位不同年齡層的對象，包含年輕人組73位（女性占78%，年齡介於15-27歲）、中高齡者組50位（女性占80%，年齡介於46-64歲）和高齡者組55位（女性占65%，年齡介於65-92歲）。參與者被邀請以紙筆方式進行測驗，並須回答當提到數位遊戲時，他們會想到什麼詞彙，參與者最多可填答12個詞彙。研究結果共測得962個詞彙，年輕人組、中高齡者組以及高齡者組分別測得640、180以及142個詞彙，後以本研究建構之數位遊戲聯想編碼架構歸納資料。三組參與者的聯想詞彙在不同編碼類目中的分布各有異同，包含：在數位遊戲使用的負面動機中，年輕人組較傾向聯想與心理有害相關之內容，中高齡者與高齡者組則較會聯想到與生理有害相關的部分；在正面動機的部分，年輕人組與中高齡者組較傾向聯想到娛樂性，高齡者組則是聯想到有用性；三組樣本皆出現的重複詞彙有：「動腦」、「有趣」、「打發時間」與「沉迷」。本研究期能啟發數位遊戲相關學術與實務工作者，在未來重視不同世代對數位遊戲的認知異同，且積極扭轉各世代對於玩數位遊戲後所產生的負面印象。 Introduction Digital technologies have driven innovation and changes in information dissemination, consumption, entertainment, and social welfare. The ability to use this innovation is often based on age, with younger generations significantly more comfortable than are older generations. This “digital divide” poses a challenge to societies such as Taiwan’s, where the National Development Council estimated that 14% of the population was above the age of 65 years in 2018 and estimated that this number would reach 20% by 2025, making Taiwan a superaged society. In such superaged societies, scholars suggest, digital technologies can be used to promote social welfare and the mental and physical health of older individuals. Digital gaming, which has the potential to bridge the gap between users of different generations, is a helpful tool for promoting the well-being of young and old alike. The perception of digital games among users of different generations may influence their motivation for playing games and their overall attitude to digital gaming. To collect diverse data from various age groups, this study employed the Word Association Test (WAT) to determine participants’ underlying cognition and emotions. Thus, the aim of this study was to investigate differences in cognitive perceptions and approach-avoidance conflict of digital games among users of different generations. The stimulus word “digital games” was used in the WAT to investigate the cognitive perceptions of different age groups regarding digital games. The study began by considering the applications of digital gaming and then reflected on the differences in the perception of digital games between young-adult, middle-aged, and older groups. Subsequently, the intergroup similarities and differences in perceptions of digital gaming were evaluated.. Method Convenience sampling was employed to recruit participants from different generations and living in Taipei, Taiwan. The young-adult participants included college students, graduate students, nearby residents, and high school students from a certain campus. The older-adult participants were recruited from neighborhoods, community centers, and locations near the aforementioned college. After invalid samples (those without age information) were excluded, 178 valid samples remained. To capture inter-age-group differences in cognitive perceptions of digital games, the participants were divided into three groups: the young-adults group, middle-aged and older-adults group, and advanced age group. The age classifications for the two older groups followed the age categories of the Ministry of Labor in Taiwan: 45 years and above and 65 years and above, respectively. The young-adults group comprised 73 participants [22% male, age of 15-27 years, mean (SD) = 20.18 (2.24)], the middle-aged and older-adults group comprised 50 participants [20% male, age of 46-64 years, mean (SD) = 59.40 (4.45)], and the advanced age group comprised 55 participants [35% male, age of 65-92 years, mean (SD) = 70.69 (4.94)]. The primary research method employed in this study was content analysis of associations with digital game vocabulary. The objective was to systematically categorize and describe data in accordance with predetermined coding categories to obtain structured and quantifiable information about content. Through the literature review conducted for this study, three coding themes were identified in cognitive perceptions of digital games: (1) neutral, (2) positive, and (3) negative game perceptions. The study’s WAT was conducted in paper-and-pencil format, and the aim was not to measure how many words the participants could provide within a set time frame. Instead, the participants were encouraged to answer with as many words as possible. The WAT was concluded when the participants indicated they could not think of any more words or when they had provided 12 words. Finally, the participants’ responses were transcribed verbatim, and the number of words provided by each participant and the summarized themes were calculated. Results The distribution of vocabulary in the three participant groups for neutral, positive, and negative game perceptions revealed that the young-adults group and the middle-aged and older-adults group gave the highest number of responses that were coded as positive game perceptions, whereas the advanced age group gave the most responses coded as neutral game perceptions. This indicated that the younger individuals may have had more positive perceptions of digital games than the older individuals did. In the coding theme of neutral game perceptions, the types of words most commonly provided by the young-adults group were those relating to game types; the three most commonly used words were competitive, simulation, and interaction. The types of words most commonly provided by the middle-aged and older-adults group were those relating to game titles, with the three most widely used words being “Mahjong,” “Candy Crush,” and “Su doku”. The types of words most commonly provided by the advanced age group were also those relating to game titles; the three most often recurring words were “Happy Farm,” “Candy Crush,” and playing cards. Interestingly, “Candy Crush” was a common word for both the middle-aged and older-adults group and the advanced age group, suggesting that this digital game is commonly played by middle-aged and older individuals in Taiwan but not by young adults. No other words were shared by the three groups in this coding theme. In the coding theme of positive game perceptions, the types of words most commonly provided by the young-adults group were those relating to entertainment, with the three most commonly used words being stress relief, fun, and happiness. The middle-aged and older-adults group gave similar responses to the young-adults group; their two most frequently used terms were fun and stress relief. The types of words most commonly provided by advanced age group were coded as utility, with the most often used terms being brain exercise, passing time, preventing dementia, and learning. Three terms were common to the three groups: passing time, brain exercise, and fun, indicating that the different age groups had similar positive perceptions of playing digital games. In the coding theme of negative game perceptions, the types of words most commonly provided by the young-adults group were those relating to psychological harm, with the most common term being addiction. The types of words most commonly provided by the middle-aged and older-adults group and the advanced age group were related to physical harm, with the often used term being eye discomfort. Notably, addiction was common to all three groups, suggesting that individuals from all generations perceive digital games as addictive. However, the middle-aged and older-adults group appeared to worry more that digital games were harmful to their eyes than that they were addictive. Conclusion This study examined and coded responses regarding perceptions of digital gaming of individuals in three distinct age groups and discovered specific differences between the groups’ responses.