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An elevated thunderstorm hail event occurred in Chenzhou and its vicinity in the Nanling region during March 22-23, 2023. A wide range of hail with diameters reaching up to 20 mm was reported, which was rare in elevated convection. In order to enhance the capability of forecasting and early warning of such hail events, this paper uses conventional meteorological observation data and SA-band dual-polarization radar products to analyze its weather conditions and dual-polarization radar echo characteristics. The results are as follows. (1) This event occurred in the cold area on the north side of the surface front, which was a typical elevated thunderstorm process. The hail-falling area was located 140 km to the north side of the surface front, and the large hail of 20 mm in diameter was caused by a supercell storm. (2) The storms that caused large hail in southern Chenzhou can be divided into four stages, which are the initial stage, the rapid development stage, the hail-falling stage, and the weakening stage. During the rapid development stage, the strong echo center increases rapidly and the vertical cumulative liquid water content (VIL) increases sharply. The differential reflectivity (ZDR) column extends to 4~5km above the 0 ℃ layer. A stronger updraft provides favorable conditions for hail development. During the hail-falling stage, with the rapid decrease of the strong echo center, the weak echo region (WER) disappears, and the height of the ZDR column decreases significantly. The values of ZDR and specific differential phase (KDP) gradually increase as the melting hail falls toward the ground. While the footprints of KDP correspond well with the hail-falling region. (3) The three-body scattering (TBSS) characteristics of large hail showed that the ZDR value at the root was large, which then decreased rapidly with the increase of radial distance, and the cross-correlation coefficient (CC) was significantly low. The sidelobal echo features of large hail indicate a low ZDR and low CC signature. These dual polarization features are key concerns for the large hail warning.

Radiation environments such as galactic cosmic rays，solar cosmic rays and radiation belts produce various space radiation effects on the components and astronauts，threaten the normal operation of spacecraft and life and health of astronauts. Material shielding is currently one of the most effective radiation protection measures and plays an important role in ensuring the smooth progress of aerospace missions. The research progress of space radiation shielding materials in different scenarios for three typical objects：components，astronauts，and aircraft platform protection is reviewed in this paper. Also the development direction of space radiation shielding materials such as metal composite materials and polymer materials is explored.

Investigating the moisture migration during the wood drying process can help improve wood utilization. Single-sided nuclear magnetic resonance (NMR) technology facilitates such investigation with its advantage in conducting one-dimensional measurements along different directions of wood, allowing for the detection of moisture transfer at different depths along the axial and transverse directions during the wood drying process. This research focused on Pinus sylvestris var.mongolica wood, on which a glue sealing technique was employed to ensure that the moisture only transfers along the axial or transverse axis, and the apparent transverse relaxation time (T2app) was utilized to delve into the changes of moisture content at various depths during the drying process. The results showed that at the first 2 hours of the drying process, there was a little free water near the evaporation surface of Pinus sylvestris var.mongolica wood, followed by a scarcity of free water during the drying process, and a noticeable moisture content gradient was observed near the evaporation surface. When the moisture transferred along the axial direction, the farther the moisture was away from the evaporation surface, the more uniform the moisture distribution was. When the moisture transferred along the tangential direction, the farther the moisture was away from the evaporation surface, the more obvious the moisture difference in each layer was. By single-sided NMR technology, it is possible to ascertain the moisture content of wood at various depths, thereby offering a theoretical framework for revealing the migration mechanism of water within wood.

During metal injection molding (MIM), water-soluble polyethylene glycol (PEG) and polymethyl methacrylate (PMMA) binder system usually lead to the formation of a large number of holes. The time spent in injection demolding increases with the size increasing of the parts for the poor thermal conductivity of the binder system. Poly (β-hydroxybutyrate)(PHB) was used as a PEG crystallization inhibitor to solve this problem. The effects of PHB content on the thermal conductivity, crystallization behavior, rheological properties of the binder, injection holding time and microstructure of the green body were studied by thermal conductivity meter, DSC, rheological experiments and fourier transform infrared spectroscopy (FTIR). The results show that in PHB / PEG blends, with the increase of PHB content, the crystallization temperature decreases from 55.18 ℃ (pure PEG) to 51.4 ℃ (25% PHB modified, mass fraction, the same as below). With the increase of PHB content from 0%-25%, the melting enthalpy and thermal conductivity of PEG blends gradually increase from 79.5 J/g to 107.6 J/g and from 0.2433 W·m-1·K-1 to 0.3469 W·m-1·K-1, respectively. The increasing of binder crystallinity leads to the improvement of thermal conductivity. Due to the complex hydrogen bond interaction in the PEG/PHB/PVAc ternary system, the crystallization temperature of the binder decreases from 50.07 ℃ of pure PEG to 43.3 ℃ of PEG with 25% PHB. The relationship between the viscosity and shear rate of the feedstock prepared with 15% PHB modified PEG binder conforms to the law of power-law fluid. And the shear thinning index of the feedstock prepared with 15% PHB modified PEG binder decreases from 0.77 of pure PEG to 0.62 at 120 ℃.Under the same injection conditions, the injection demolding time is significantly shortened from 100 s (unmodified) to 50 s of PEG with 15% PHB. Meanwhile, the injection green body, with smooth surface, few and uniform distribution internal holes can be obtained using 15% PHB modified PEG binder.

Oxide eutectic ceramics have excellent high specific strength, high temperature resistance, corrosion resistance, oxidation and creep resistance, and so on, which are considered to be the promising materials to be used in ultra-high temperature oxidation, corrosion and other extreme environments. It shows great application prospects in the new generation of high thrust-to-weight ratio aero-engine for high-temperature hot-end structural components. Laser additive manufacturing technology has become one of the most promising cutting-edge technologies for the preparation of high-performance complex structural components in recent years. Crack defect is easy to occur in the process of laser rapid solidification of ceramics, which seriously affects the quality and performance of the oxide eutectic ceramics components. So, it has become a key factor restricting the engineering application. Two typical laser additive manufacturing technologies for ceramics including laser engineered net shaping and laser power bed fusion were briefly summarized. The crack morphology characteristics of different shaped components formed by the above two technologies were analyzed and compared. The formation mechanism of cracks in laser additive manufacturing of oxide ceramics was explored from the perspectives of microstructure characteristics, stress state. Further, a systematic summary was presented focusing on the improvement of microstructures and the reduction of thermal stress to inhibit crack formation through optimization of process parameters, compositional design, and outfield assistance. Finally, it is pointed out that the future development trends and breakthrough directions of oxide eutectic ceramics by laser additive manufacturing in terms of powder properties, forming primary and secondary factors, and forming technology research.

On the afternoon of 4 April, 2023, an intense downburst event (referred to as the '4.04' strong downburst) occurred in Hengyang, Hunan, causing serious disasters. This study analyzes the key warning indicators and environmental conditions for extreme strong winds using conventional meteorological observations, Doppler weather radar, and NCEP 1°×1° reanalysis data. The results are as follows: (1) The '4.04' strong downburst occurred under a 'baroclinic frontogenesis' weather system configuration, with a surface cold front providing the triggering conditions. The Skew-T plots clearly showed characteristics of high-level dryness and low-level moisture, unstable atmospheric convective parameters, and corrected convective available potential energy (CAPE), along with strong vertical wind shear, all conducive to the occurrence of extreme strong winds. (2) A mesoscale convective system (MCS) with bow echoes swept through Hengyang, causing regional downbursts. Extreme strong winds occurred when the corresponding storm cells moved rapidly, with maximum reflectivity factors reaching 60 dBz. The vertical integrated liquid water content and centroid height rapidly decreased. The reflectivity factors displayed a noticeable tilted structure, with clear features of bow echoes, rear-inflow jets, and radial velocity ambiguity. The low elevation asymmetric high-speed regions and velocity convergence are key warning indicators for extreme strong winds. (3) The strong downburst exhibited significant convective potential, with strong low-level moisture flux convergence and high specific humidity. There were conditions of thermal instability and vertical upward motion, along with low-level convergence and upper-level divergence. Cold air played an important role in the occurrence and development of this downburst event.

[Objective] In order to provide a reference for the formulation of sectoral water conservation strategies for the Haihe River Basin, it is urgent to systematically identify the leading driving factors for changes in water consumption by sector in the Haihe River Basin economic system and quantify their driving effects. [Methods] First, a set of input-occupancy-output tables with water resources of 49 sectors of the the Haihe River Basin at constant price in 2007, 2012 and 2017 were compiled. Based on these tables, a structural decomposition analysis model of changes in sectoral water consumption with 11 driving factors was constructed. [Results] (1) From 2007 to 2017, the improvement of economic development level was the main reason for the increase of total water consumption, but its driving effect weakened with time. The decrease of industrial production water intensity and the change of final demand structure of sectoral products were the main reasons for the decrease of total water consumption during 2007-2012 and 2012-2017, respectively. (2) Irrigation water intensity and the final demand structure of sector products were the most important factors for the decrease in water consumption of agriculture during 2007-2012 and 2012-2017, respectively. (3) The driving effect of production water intensity on the change of water consumption in the industrial sectors weakened over time. The growth of final demand for products of industrial sectors continued to drive the increase of water consumption in the industrial sectors. (4) The change of the production technology level and the total final demand structure had a stronger driving effect on the increase of water consumption in the service sectors than in the agricultural sector and the industrial sectors. [Conclusion] From 2007 to 2017, the reduction of total water consumption in the Haihe River Basin showed a trend of change from being mainly driven by water conservation technology to being mostly driven by final demand structure. From the perspective of inter-industrial comparison, the main driving factors of water consumption change in different industries had obvious sectoral characteristics. We recommend to formulate water conservation measures for each industry based on its main drivers of water consumption change.

Background A megawatt-class nuclear power system has been developed by coupling a heat pipe reactor with a supercritical carbon dioxide (S-CO2) Brayton cycle. This system offers advantages in terms of high safety, power density, and compactness. Purpose This study aims at the operation characteristics of this power system with high efficiency and compactness. Methods The coupling code of a self-developed heat pipe reactor transient analysis code, Transient Analysis code for heat Pipe and AMTEC power conversion space Reactor power System (TAPIRS), and supercritical carbon dioxide Brayton cycle transient analysis code (SCTRAN/CO2) were utilized to analyze the open-loop dynamic characteristics under conditions of reactivity disturbance, load disturbance, cooling water temperature disturbance, and cooling water mass flowrate disturbance. Then, the control system was designed. On this basis, three load variation operation conditions, i.e., linear load variation, stepped load variation, and load rejection, were simulated and analyzed. Results The simulation results show that the rotational speed of the new nuclear power system is sensitive to the disturbances and needs to be controlled. The bypass flowrate increases under low load conditions, hence the flowrate of the compressor needs to be controlled as well. The system can adjust the load from 0% to 100% at a rate of 6% FP (full power)·min-1. It is capable of implementing stepped load changes, although it experiences slightly more pronounced fluctuations. Under load rejection conditions, the stabilization time might be prolonged, but it will eventually stabilize with all parameters remaining within safe limits. Conclusions This study provides a reference for the conceptual design of new nuclear power systems with high efficiency and compactness.

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.

Nanoscale zero-valent iron（nZVI） is a kind of widely-concerned environmental remediation material，which expands the application scope of iron-based materials in site remediation and pollutant removal because it has both the reactive activity of nanoscale materials and the reductive property of zero-valent iron. Although nZVI is more effective，the more complex preparation process leads to increased environmental footprint and production costs，the preparation method of nZVI is becoming a key constraint to its development. The paper introduced the development of nZVI and carded the various preparation methods and characteristics of nZVI from the perspective of sustainable development. Furthermore，this paper examined the potential environmental consequences resulting from the preparation process of nZVI. On this basis，the sustainability of typical nZVI preparation was assessed，and potential unsustainable factors were quantified，highlighting the dependence of the preparation process on electrical energy sources. Based on the existing researching，the large-scale and potential methods of preparation of nZVI were prospected，such as laser ablation. Moreover，it illustrated the importance of choosing reasonable preparation method，emphasizing the indispensable position of the sustainability assessment of nZVI in the future development. It is hoped to provide a reference for researchers and policy makers in the selection and improvement of nZVI preparation methods.

The steep slopes on both sides of the hydropower station in the southwestern mountainous region develop a multitude of dangerous rock formations. The rolling, collapsing and falling of these hazardous rocks have profound implications on the normal operation of the dam, main buildings, factories, roadways, and slope support systems. At present, the prediction and protection measures against rockfall disasters are predominantly reply on the two-dimensional Rockfall method, which ignores the spatial geometry of these dangerous rocks. In reality, falling rockfalls exhibit three-dimensional motion, and their threat zone extends throughout a three-dimensional geographical space. In view of this, this study is based on the hazard assessment results of the hidden danger investigation in a specific hydropower station of Yunnan Province. It employs field investigations, airborne LiDAR remote sensing measurement technology, and unmanned aerial vehicle (UAV) oblique photography technology to obtain high-precision laser radar point cloud data for the study area. This data is used to constrct detailed rock mass models and authentic three-dimensional scene models. The analysis includes historical rockfall distribution characteristics, rock mass structural characteristics, characteristics of hazardous rock masses in collapse source areas, and unstable modes. Furthermore, the study utilizes Unity3D three-dimensional rockfall analysis methods to simulate the motion characteristics of dangerous falling rocks after collapse. This enables the determination of the trajectory of dangerous falling rocks, as well as parameters such as bounce height, impact energy, and rolling area at different locations. The results indicate that for the right bank dangerous rock area of the hydropower station, a typical dangerous rock mass can achieve a maximum bounce height of up to 7.92 meters, with an impact range of approximately 145 meters. Most of these rocks roll towards the dam, which has multiple levels of passive protection nets and does not pose a threat to important facilities within the power plant. In the case of the right bank dangerous rock area two, after the collapse of dangerous rocks masses, the impact range of the falling rocks is approximately 120 meters, and some of the falling rocks may roll along the road embankment onto the road, potentially posing a threat to the main traffic artery. On the left bank, dangerous rock area one has a massive and unstable typical rock mass, with a maximum bounce height of up to 9.02 meters, ultimately falling into the reservoir storage area. Hazardous rock area two on the left bank has a dense distribution of hazardous rock masses, with a significant quantity, and after collapse, the impact range is approximately 380 meters. However, due to the dense vegetation cover on the slope, most of the falling rocks accumulate on the slope surface, posing a certain threat to pedestrians and vehicles. The related research results can provide valuable insights for the identification of hazardous rock masses and simulation of rockfall events in similar hydropower facilities.

The multi-cell storm stage and squall line stage of a severe convective weather process over the Dongting Lake on 15 May 2021 in this study are analyzed mainly based on S-band dual-polarized doppler weather radar data. The study focuses on the analysis of the supercell storm I2 in the multi-cell storm stage. The results are as follows. (1) During the initial period of the I2, the strong echo area (the horizontal reflectivity factor, ZH > 55 dBz) and the differential reflectivity factor (ZDR) column (ZDR > 2.5 dB) extend to Wet Blub Zero (WBZ) level, corresponding to the areas with large specific differential phase (KDP) (> 1.7 °·km-1) and large correlation coefficient (CC) (0.9-0.99). It indicates that during this period, the precipitation phase is dominated by water condensate mingled with large raindrops, and these supercooled raindrops provide hail embryos for the later hail development. (2) During the hail colliding-growth period of the I2, ZH intensity and height increase rapidly, and vertically integrated liquid water content (VIL) shows an obvious leap increase. The strong-echo center (ZH > 60 dBz) extends to the level of above -10 ℃. In the corresponding regions, the ZDR drops below 0, the ZDR column (ZDR> 2.5 dB) extends to the level of -10 ℃, CC drops, and a "hole" appears in the KDP value area. These indicate that the precipitation during this period is dominated by solid particles and these solid particles are in an increasing period. (3) During the mature hailfall period of the I2, the bottom of the ZH intensity center (ZH > 60 dBz) drops below the WBZ level and the CC is locally as low as 0.8. There are ZDR negative areas and KDP voids in the corresponding area. These means that the dragging effect of the falling hail further weakens the strength of the updraft, which means that the hail is about to land. Then comes the squall line stage. (4) Unlike the multi-cell storm stage, the squall line stage has anomalously large KDP values and ZDR values greater than 1. (5) Before the occurrence of extreme gales of the squall line stage, the areas with strong echo greater than 55 dBz and velocity larger than 27 m·s-1 extend below 1 km, and the KDP in the strong echo area is obviously large, corresponding to the strong downdraft. Besides, the strong precipitation dragging effect caused by the melting of descending precipitation particles intensifies the generation of extreme gales.

This is an essay in the field of mineral processing engineering. This work investigates the effects of two cationic collectors, dodecyl amine (DDA) and dodecyl trimethylammonium chloride (DTAC), on flotation of quartz. Based on micro flotation tests, adsorption measurement, zeta potential measurement and infrared spectrum analysis, the author studied the recovery of quartz, the adsorption of the two kinds of collectors on quartz and the changes of zeta potential of quartz influenced by the collectors at different pH condition and concentration. The results of the experiments show that the recovery of quartz can be increased to approximately 100% by both dodecyl amine and DTAC, with 1×10-4 mol/L concentration, at neutral pH condition， however, at much lower pH condition, neither of the collectors can get a decent recovery of quartz. Additionally, in this concentration, the isoelectric point of quartz is able to be pushed to almost pH value 4 from around pH value 3 by both of the collectors; at neutral pH condition, with the concentration of either of the two collectors climbing, the zeta potential of quartz can be turned from negative to positive; at strong alkaline conditions, due to the disparities of the molecular structures, the types of the adsorptions are not exactly similar.

In this study, time-domain nuclear magnetic resonance (TD-NMR) technology was employed to explore the moisture state and spin-spin relaxation (T2) characteristics of polymethyl methacrylate (PMMA) wood-plastic composites during the moisture absorption and water absorption process. The moisture resistance and water repellency of PMMA wood-plastic composites were compared and analyzed. The experimental samples were PMMA wood-plastic composite material produced by impregnated methyl methacrylate (MMA) monomer polymerization. Firstly, the NMR T2 test was carried out on the dry PMMA wood-plastic composite, and then the moisture absorption and water absorption experiments were carried out respectively, and the mass of the specimen and its T2 signal were measured at intervals. The results showed that the moisture absorption rate and water absorption rate of PMMA wood-plastic composite were lower than those of untreated wood, and PMMA had good moisture resistance and water resistance. When the impregnation concentration of MMA was 100 % and the impregnation time reached 24 h, the moisture absorption rate of wood-plastic composites was lower than 15% under the constant temperature of (40±0.2)℃ and relative humidity of (96.4±0.4)%, and the water absorption rate of water-absorbing specimens at room temperature was lower than 30%. At the same impregnation time, with the increase of impregnation concentration of MMA, the moisture absorption rate and water absorption rate of PMMA wood-plastic composites decreased significantly, and the T2 peak area decreased gradually. This indicates that the PMMA inside the wood-plastic composite material contributes to preventing water from entering.

Objective This study aims to reveal the distribution patterns and characteristics of co-seismic geological hazards in earthquake swarms, clarify the differences in induced geological hazards by different types of earthquakes, further understand the seismic risks around and within the Bayan Har Block, and provide efficient guidance for the prediction and prevention of secondary geological hazards induced by earthquakes. Methods We take the co-seismic geological hazards of the Maerkang MS 6.0 earthquake swarm in 2022 as the research focus. Through systematic data and results analysis on earthquake swarm sequence, regional tectonic environment, regional crustal deformation, and post-earthquake short-term geological hazard, the regional and deep structural environment of the Maerkang MS 6.0 earthquake swarm and the main controlling factors of co-seismic geological hazards are revealed. Results The results show that the Maerkang MS 6.0 earthquake swarm is a deep-seated sticky-slip earthquake that occurred on a secondary fault in the active strong earthquake zone within the Bayan Har block, a region with extremely strong peripheral boundary activity. The earthquakes with similar magnitudes may be the result of ruptures of secondary faults of the Songgang fault and the successive ruptures of the barriers between them. The earthquake has resulted in 83 newly discovered geological hazard risks, exacerbating deformation in 106 existing hazard spots and triggering multiple high-altitude landslides and a series of fractured mountain slopes. The areas of extreme, high, and medium geological hazard risk in Caodeng Town, the epicenter area after the earthquake, account for 1.62%, 4.80%, and 12.37%, respectively. The occurrence of secondary geological hazards following earthquakes exhibits a positive correlation with the earthquake magnitude, with the number increasing linearly as the magnitude rises. Conclusion The significant differences in the GPS horizontal velocity field and vertical velocity field on both sides of the Darlag–Songgang–Fubianhe fault zone are key factors contributing to the activity of this fault and triggering the recent earthquake.The main controlling factors of co-seismic geological hazards induced by earthquakes are, from primary to secondary, the ruptured fault and its associated faults, seismic magnitude and energy attenuation, terrain slope and altitude difference, and rock mass structure and density of structural surfaces. Significance This study predicts a high risk of future strong earthquakes in the intersection area of the Songgang fault, which triggered this earthquake, and the Longriba active fault. The surrounding area of the seismogenic fault and its associated faults are at a high risk of geological hazards during earthquakes. The findings provides a reference for predicting and controlling the risk of co-seismic geological hazards in this area.

The study of carbon economics theory and its evolutionary laws in the context of carbon peaking and carbon neutrality is crucial for advancing global carbon emission reduction efforts and understanding the interaction between carbon markets and complex socioeconomic systems. Carbon markets play a significant role in reducing greenhouse gas emissions through the implementation of a theoretical carbon trading mechanism. This paper proposes a theoretical framework based on the concepts of “externality” and public goods theory, focusing on Pigouvian tax, Coase theorem, and the distribution of carbon emission rights through quotas. It also explores the underlying economic principle of the “green premium”. Carbon financing is expected to support future advancements in carbon-neutral technologies. Therefore, this paper summarizes the theory and examines the relationship between carbon trading and carbon finance markets. The mechanism of the carbon market operates based on supply and demand dynamics, and now the market is witnessing gradual expansion in which other evolutionary laws also play parts, such as carbon price fluctuations,improvements to the regulatory system, and the diversification of market participants. The main instruments in the carbon market include carbon taxes, trading, and offsets, with governments, businesses, and individuals playing different roles. This paper provides a systematic analysis of theoretical innovations and practical achievements in carbon market economics, serving as a valuable reference for strategic decision-making and technological innovation in the pursuit of carbon peaking and neutrality goals.

Lumbar spinal stenosis (LSS) is a common disease in orthopedics. The American Society of Pain and Neuroscience (ASPN) published a new version of minimally invasive treatment practice guidelines in 2022 to improve the clinical efficacy of LSS. A total of seven treatments for LSS were included in the guidelines, including percutaneous image-guided lumbar decompression (PILD), interspinous spacers (ISP), interspinous fusion (ISF), intrathecal drug delivery systems (IDDS), spinal cord stimulation (SCS), epidural steroid injections (ESI) and open decompression. Based on the guidelines, this paper summarizes and discusses the research progress of minimally invasive treatment of LSS in the context of the clinical situation, aiming to provide a reference for clinicians and further related researches.

Bionic coatings with excellent properties such as wear resistance and corrosion resistance can be used in harsh environments such as marine， petroleum， and chemical industries.Hence， it is of great significance for the preparation of advanced bionic coatings to study the bionic structure of natural biological materials， preparation methods and quality control methods of bionic coatings.In this work， the research statuses of bionic coatings prepared by high-energy beam cladding technology were introduced from two aspects: the preparation of bionic coatings and the quality control of bionic coatings by high-energy beam cladding technology.In terms of preparing bionic coatings by high-energy beam cladding technology， according to the classification of different bionic mechanisms， the strengthening mechanism of bionic coatings and the research status of coatings using high-energy beam preparation methods were reviewed.In terms of quality control of bionic coatings， the role of process optimization and numerical simulation in the preparation process in regulating the performance of bionic coatings prepared by high-energy beam cladding technology was explained.Finally， the shortcomings in the current research were summarized， which could provide reference directions and prospects for subsequent researches.

SiCp/AZ91D magnesium matrix composites are widely used in the aerospace field, but there is less report on the distribution of SiCp particles in SiCp/AZ91D magnesium matrix composites by ultrasonic testing methods at home and abroad. In this paper, SiCp particle reinforced magnesium matrix composites with volume fractions of 0%, 2%, 4% and 6% were prepared by squeeze casting. In order to study the particle distribution in composite materials, ultrasonic velocity method, ultrasonic attenuation method, ultrasonic characteristic scanning imaging method and nonlinear ultrasonic testing method were used to study the dispersion of SiCp particles. The relationship between various acoustic parameters and SiCp volume fraction, and the difference of detection ability of different detection methods for SiCp particle distribution were explored and verified by experiments. The results show that ultrasonic characteristic scanning detection and ultrasonic velocity method can quantitatively detect SiCp macro agglomeration, ultrasonic attenuation method can have a good effect on characterizing both micro agglomeration and macro agglomeration, and nonlinear ultrasonic detection method is more sensitive to detecting SiCp micro agglomeration. When the particles are uneven, the mechanical properties are most affected, and the tensile strength is greatly reduced.

The effect of γ-aminobutyric acid (GABA) treatment on chilling injury in cold-stored kiwifruit and its relationship with reactive oxygen species (ROS) metabolism were investigated. Postharvest kiwifruit were treated with 2.0 mmol/L GABA solution for 20 min and stored at (4 ± 1) ℃ and (85 ± 5)% relative humidity. Chilling injury development was evaluated and the changes in the dynamic balance between the production and removal of ROS were analyzed. The results showed that compared with the control group, GABA treatment could delay the increases in the chilling injury index, cell membrane permeability and malondialdehyde (MDA) content of cold-stored kiwifruit, inhibit the rate of superoxide anion radical production and the increase in hydrogen peroxide content, and increase and maintain superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), glutathione reductase (GR), monodehydroascorbate reductase (MDHAR) and dehydroascorbate reductase (DHAR) activities. Moreover, GABA treatment slowed down the decrease in the contents of ascorbic acid and glutathione, which contributed to higher antioxidant capacity levels in the fruit. The above findings indicated that exogenous GABA treatment could maintain dynamic redox balance, attenuate membrane lipid peroxidation and preserve cell membrane integrity in cold-stored kiwifruit by inhibiting the accumulation of ROS, and increasing the activities of the enzymatic and non-enzymatic ROS systems, thereby enhancing cold stress resistance and ultimately delaying chilling injury.

Objective To explore the clinical application effect of a pharyngeal swab samples collection device in nucleic acid testing. Methods A total of 120 hospital staff members who conducted nucleic acid testing were randomly divided into the control group and study group, with 60 cases in each group. The control group adopted regular method of pharyngeal swab samples collection, while the study group used the new type device for pharyngeal swab samples collection. The time cost in sample collection was recorded. The degree of comfort and satisfaction in objects of sample collection were measured. Results The time spent in sample collection was (22. 84±2. 57)s in the study group, which was shorter than that in the control group (P＜0. 05). The degree of comfort and satisfaction in objects of sample collection were higher than in the study group than those in the control group (P＜0. 05). Conclusion The new type of pharyngeal swab samples collection device is effective to improve the efficiency of sampling in nucleic acid testing. (目的 探讨一种新型咽拭子采集装置在核酸检测中的应用效果。方法 选取核酸采集点进行采样的医务人员120人, 随机分为试验组和对照组, 各60人。对照组采用常规咽拭子采集方法, 试验组采用新型咽拭子采集装置采集。记录两组咽拭子采集时间, 评价被采集对象的舒适度和满意度。结果 试验组咽拭子采集时间(22. 84±2. 57)s, 短于对照组(27. 56±2. 44)s, 差异有统计学意义(P＜0. 05)。试验组舒适度和满意度均高于对照组, 差异有统计学意义(P＜0. 05)。结论 新型咽拭子采集装置能有效提高采样效率。)

Seed rain can affect species composition, forest community diversity, and plant population and community renewal. Studying the characteristics of seed rain is of great significance for in-depth research on regeneration strategies and restoration of plant population. In order to explore the basic characteristics of seed rain in fragmented habitats, this study used monthly seed rain data collected from 2015 to 2020, and used the Kruskal-Wallis test to analyze the annual difference of the seed rain density of woody plant, and to analyze the monthly difference of the seed rain density of species with different dispersal syndromes. Then we used linear mixed-effect models to test the relationships among island spatial attributes (i. e., island area, the distance to the mainland, and the distance to the nearest island), climatic factors (i. e., accumulated temperature above 0 degrees, precipitation) and seed rain density of woody plant and species with different dispersal syndromes. The results were as follows: (1) During the six years of 2015-2020, a total of 877 178 mature seeds of woody plant were collected from 240 seed traps in 29 study islands, belonging to 26 families, 40 genera and 52 species. (2) Zoochory was the major dispersal syndrome in the Thousand Island Lake, there were great differences in the temporal dynamics of seed rain in different dispersal syndromes. (3) The annual density of seed rain of woody plant was significantly positively correlated with island area and annual accumulated temperature, and significantly negatively correlated with annual precipitation. (4) The monthly density of seed rain of autochory was significantly positively correlated with the distance to the nearest island, while that of zoochory was significantly positively correlated with the distance to the mainland, and that of anemochory was significantly positively correlated with the monthly accumulated temperature. In conclusion, habitat fragmentation affect the temporal dynamics of the seed rain of woody plant through island spatial attributes.

In order to stably exert the best obstacle-surmounting performance of the wheel-track compound robot, a new wheel-track compound robot that can switch multiple motion modes according to the environment is developed. The robot can switch between the upright motion and the crawler motion mode, and the position of the center of gravity of the robot can be greatly adjusted by the rotation of the swing arm, which has better obstacle-surmounting performance. On the basis of gait planning and motion mechanism analysis of the robot, kinematics and dynamics analysis of the typical step crossing motion process are carried out, which verifies the feasibility of the robot mode switching, and calculates the maximum theoretical value of the step height that the robot can climb. Finally, using the simulation software, according to the theoretical values obtained by the calculation, the simulation test of the robot's step climbing process is carried out. The results verify the accuracy of the calculated values and the obstacle-surmounting performance of the robot.

On 26 June 2023, a catastrophic debris flow occurred in the Banzi Catchment in Wenchuan county of Sichuan province. This debris flow event is a viscous debris flow triggered by short duration heavy rainfall. The volume of debris which transported out of the catchment by debris flow is more than 8.3×105 m3, and the debris flow blocked the Minjiang River. The river blockage formed a barrier lake with an area of about 0.4 km2. To reveal the formation mechanism of the occurrence of the extremely large debris flow events 15 years after the Wenchuan earthquake, This paper adopts a comprehensive method of field investigation, image interpretation, topographic superposition and calculation of forced vortex. This paper also analyzes the formation mechanism of debris flow and the characteristics of river blocking. Based on the results, this paper gives some suggestions of investigation and prevention of debris flow in the Banzi catchment. The research results show that (1) the triggering rainfall is characterized by short duration and high intensity. The main initiation positions are in the channel. The main debris supply is from the debris deposition along the channel. (2) The peak discharge of debris flow is as high as 755.5 m3/s, which is the main cause of river blockage. (3) Since the Wenchuan earthquake, the debris flow activity of the Banzi Catchment has the characteristics of lag and long-term because of the coupled transport of debris on the slope and along the channel. (4) The volume of the debris source which can be eroded along the channel should be paid more attention in subsequent investigation and prevention. The research results are helpful in better understanding of the activity evolution of the post-seismic debris flow. They can also provide scientific references for the prevention of the post-seismic debris flow..

To investigate the effects of different concentrations of antimicrobial peptide from marine Bacillus subtilis on the quality changes of freshly squeezed cucumber juice during the storage period (5 d) at room temperature. Sensory evaluation, physicochemical analysis (pH, stability coefficient, total sugar content, total bacteria count), and electronic nose technique (principal component analysis, radar plot, corresponding values of primary flavor components sensors) were used to comprehensively evaluate the effect of freshness preservation. The results showed that the concentration of antimicrobial peptide was positively correlated with various physicochemical indexes. And 2×MIC concentration of antimicrobial peptide had the best effect, with the highest sensory score (7.03), pH (4.97), stability factor (32.86%), total sugar content (5.11 mg/mL), and the best antibacterial effect (0.88 log CFU/mL). Principal component analysis (PCA) showed that the flavor characteristics of cucumber juice in each antimicrobial peptide treatment group were similar, while the flavor characteristics of cucumber juice in the control group and the potassium sorbate treatment group were similar. The radar plot revealed that the flavor components of cucumber juice in each antimicrobial peptide treatment group increased at the later stage of storage (5th d), while the flavor components of cucumber juice in the control and potassium sorbate treatment groups remained unchanged basically during the storage period. The analysis of the response values of the flavor component sensors showed that the antibacterial peptide from Bacillus subtilis BBW1542 had a certain impact on the volatile flavor compounds in freshly squeezed cucumber juice. In conclusion, the preservation effect of antimicrobial peptide from B. subtilis BBW1542 was significantly better than that of the chemical preservative group (P

Background The occurrence and development of osteoporosis experience a long process, therefore, attention should be paid to bone health throughout the whole life cycle of human, early prevention and treatment of osteoporosis is of positive significance. There is a relative lack or insufficiency of research on TCM symptom assessment in the high risk population of osteoporosis in Ling-nan region.Objective To conduct expert questionnaire analysis on the assessment of TCM symptoms in high risk population of osteoporosis in Ling-nan region and form expert consensus opinions.Methods Based on the previous literature review and the first round of "Questionnaire for TCM symptom assessment in high risk population of osteoporosis in Ling-nan region", the Delphi method was adopted to optimize the second round of expert questionnaire from October 2021 to September 2022, in combination with the expert opinions of the first academic conference of Ling-nan bone and joint disease in December 2021 and the expert group of Guangdong Provincial Association of Chinese Medicine concerned Specialist Committee on Bone and Joint Degeneration and Injury. The experts in the department of orthopedics in Ling-nan region were consulted for their opinions, and the data of the investigation results were statistically analyzed.Results 192 experts with solid theoretical knowledge and clinical diagnosis and treatment skills in TCM or Chinese and western integrative medicine were selected from various provinces and cities in the Ling-nan region. The research fields of the surveyed experts included orthopedics and traumatology of Chinese medicine, orthopedics and traumatology of Chinese and western integrative medicine and clinical rehabilitation, etc. involving TCM clinical practice, Chinese and western integrative medicine clinical practice and scientific research, etc. Among them, there were 115 male experts, 77 female experts, 31 experts with senior professional titles, 76 experts with associate senior professional titles and 85 experts with intermediate professional titles, with the duration of carrying out specialty not less than 6 years. The expert positive coefficient was 100%, and the average authority coefficient was (0.81±0.04) . The concentration and coordination degree of the surveyed experts' opinions were relatively higher, that is, the sample mean±coefficient variation of the TCM symptom items of high risk population of osteoporosis in Ling-nan region included " humpback deformity" (88.93±13.46, 15.14%) , "generalized bone pain" (89.45±14.56, 16.28%) , "fracture occurred in recent 5 years" (85.68±17.44, 20.36%) , "low back pain" (84.51±15.27, 18.07%) , "shortened height" (82.94±16.14, 19.46%) , "heavy joints unable to bend or extend" (80.21±14.43, 17.99%) , "heavy body trapped" (76.17±17.22, 22.60%) , "tiredness" (75.26±14.69, 19.52%) , "tooth shaking and hair loss" (74.87±15.87, 21.20%) , etc.Conclusion The motivation and professionalism of experts surveyed by "Questionnaire for TCM symptom assessment in high risk population of osteoporosis in Ling-nan region" are good with a wide distribution region and good representation. The preferred items of TCM symptoms of high risk population of osteoporosis in Ling-nan region were "humpback deformity" , "generalized bone pain" , "fracture occurred in recent 5 years" , "low back pain" , "shortened height" , "heavy joints unable to bend or extend" , "heavy body trapped" , "tiredness" , "tooth shaking and hair loss" , etc. The recommendations of experts in this field on the TCM symptoms assessment in high risk population of osteoporosis in Lingnan region can be better summarized based on Delphi method, which can provide references for the subsequent early diagnosis of osteoporosis and the development of the assessment scale.

Early diagnosis of frailty is of great value in helping the elderly to regain their health, as it is a non-specific state of reduced physiological reserve, resistance to disease and ability to recover from stress caused by the impairment in homeostasis maintained by multiple systems with sarcopenia as the basic characteristic. Recent developments in multiomic techniques provide new approaches to the detection of potentially specific, stable and reliable biomarkers of pre-frailty. We collected and reviewed recent advances in multiomic techniques for identifying frailty biomarkers, involving genomics, transcriptomics, proteomics and metabolomics, which can assist in assessing the risk of frailty, exploring potential mechanisms of frailty and developing targeted interventions to support healthy aging.

This article summarizes the experience of Traditional Chinese Medicine(TCM) nursing appropriate techniques for a diabetic patient with back carbuncle treated with vacuum sealing drainage (VSD) technology. Efforts have been made to enhance the continuous vacuum sealing drainage. Based on the TCM theory, nursing appropriate techniques such as auricular acupoint pressing, intradermal needling, TCM oral care, TCM five-tone therapy were carried out for management of blood pressure and diabetes mellitus, reduce the incidence the infection and improve the wound healing. (本文总结1例负压封闭引流技术(VSD)联合中医适宜护理操作技术治疗糖尿病合并背部外痈患者的护理经验。术前做好充分准备, 术后做好VSD持续引流的观察与护理。基于中医基础理论, 采用耳穴刺激、皮内针刺激、中药漱口液清洁口腔、中医五音疗法等中医护理适宜技术, 有效控制高血压、糖尿病等基础疾病, 降低感染风险, 促进创面的愈合。)

In order to explore the responses of growth, photosynthetic characteristics and nutrient accumulation of Cunninghamia lanceolata container seedlings to different amounts of slow-release fertilizer application. In this paper, the effects of different amounts of slow-release fertilizer application treatments (0, 200, 400, 800, 1 000 and 1 200 g·m-3) on the growth of seedlings height, ground diameter, biomass, photosynthetic pigment content, chlorophyll fluorescence characteristics and nutrient content of C. lanceolata seedlings were investigated. Moreover, subordinate function value method was also employed to comprehensive evaluate the growth and physiology indexes of seedlings under different fertilization treatments, and screening suitable slow-release fertilizer levels for the growth of C. lanceolata seedlings, which providing reference for the efficiency cultivation of high quality C. lanceolata seedlings. The results were as follows: (1) Compared with the control, the slow-release fertilizer application could promote the growth of seedling height, ground diameter and the accumulation of total biomass of C. lanceolata seedlings to varying degrees. (2) The slow-release fertilizer treatments could significantly increase the contents of chlorophyll and carotenoid in leaves of C. lanceolata compared with control. In addition, slow-release fertilizer treatments also increased the values of maximum fluorescence(Fm), variable fluorescence(Fv), maximum photochemical efficiency of PS Ⅱ(Fv/Fm), potential photochemical efficiency of PS Ⅱ(Fv/Fo) and actual quantum yield(QY) to varying degrees compared with control. (3) The slow-release fertilizer treatments could promote the nutrient accumulation in seedlings of C. lanceolata to varying degrees, among which the contents of Mn, Fe and Zn were found to be changed most significantly. (4) The results of subordinate function value method showed that when the amount of slow-release fertilizer application was 1 000 g·m-3, its membership value was the largest, which indicated that the comprehensive growth of seedlings under this treatment was the best. In conclusion, the amount of 1 000 g·m-3 slow-release fertilizer application is the most suitable treatment for the cultivation of high quality seedlings of C. lanceolata in the present study, under this treatment, the growth of C. lanceolata seedlings can be improved by increasing the accumulation of nutrient elements closely related to photosynthesis, thus increasing the contents of photosynthetic pigment in leaves, which in turn enhance the PS Ⅱ photosynthetic efficiency and electron transfer rate, further enhance the efficiency of light energy capture and utilization of leaves, and ultimately improve seedling growth.

In order to study the source of typical gelatin in different types of Ejiao products, nine common Ejiao products on the market including three kinds of Ejiao cake, Ejiao oral liquid and Ejiao granule, were selected as the research objects. Moreover, 1% bovine gelatin and porcine gelatin were added in Ejiao products, respectively. High-performance liquid chromatography-mass spectrometry (HPLC-MS/MS) was used to identify the characteristic peptides of typical gelatin including donkey gelatin, bovine gelatin, and porcine gelatin. The results showed that different characteristic peptides of typical gelatin were detected in nine kinds of Ejiao products. Through further analysis, it was found that the common characteristic peptides of donkey gelatin, bovine gelatin, and porcine gelatin shared by these 9 Ejiao products were 25, 3, and 14, respectively, where the unmodified characteristic peptides were 7, 2, and 3 in turn. Among them, 22, 2, and 5 common characteristic peptides were derived from the α1 chain, respectively. Meanwhile, 3, 1, and 9 common characteristic peptides were derived from the α2 chain, respectively. These common characteristic peptides could be used as the basis for the identification of gelatin sources in complex systems by HPLC-MS/MS, and give guiding significance in gelatin identification for different Ejiao products.

Based on the conventional meteorological observation data, the NCEP reanalysis data, the dual-polarization radar data, wind pro? filer radar data, and other datasets, the environmental conditions and dual-polarization radar characteristics of the phase transformation of precipitation in a rain and snow event in Hunan in late December 2021 is studied. The results are as follows: (1) The disappearing of dry lay? er, the thickening of wet layer, the whole-layer wet bulb temperature below 0 ℃, and the saturated stratification in the cold pad under the in? version layer before the snowfall favored the further cluster growth of falling snowflakes, resulting in the further enhancement of snowfall. (2) That the southwest jet exits at 700hPa and the strong water vapor convergences at 600-800 hPa, combined with the significant vertical up? draft at the middle and lower layers, provided sufficient moisture for the snowstorm. (3) The intermittent light rain (snow) in the evening of the 25th is closely related to the transit of short-wave trough frequently. In the morning of the 26th, the southwesterly wind turned to the westerly wind, which led to a short-term weakening of snowfall in Changsha. Furthermore, the warm-humid southwesterly flow strengthened over the cold pad, and the southeast wind in the cold pad turned to the northeast wind, which corresponded to the two peaks of snowfall in Changsha on the 26th. (4) There are certain differences in the correlation coefficient (CC), differential reflectance (Zdr), and horizontal reflectance factor (Zh) of different phases of precipitation. The dual-polarization products have a certain indication effect on the identification of rain and snow phases of this case. (5) The low-level"zero-velocity-level"is straight, and has the characteristics of wind-speed convergence, enhanced southwest jet core, and downward extension, etc., indicating that the dynamic climbing of warm-humid airflow over the cold pad would increase, and the snowfall could be maintained for a long time and would increase gradually. However, with the appearance of divergence of wind field, the snowfall gradually weakened. The findings of this study provide helpful criteria for the development, maintenance, and weak? ening of snow, which can be applied to the operational work of snowstorm nowcasting and forecasting.

The existing wireless communication technologies in wireless blind spot coverage have challenges in non-line-of-sight scenarios in coal mines. In order to solve the above problems, a solution approach is proposed to introduce intelligent reflecting surface (IRS) into the wireless communication system in coal mines to achieve blind compensation of wireless signal coverage. This paper analyzes the causes of wireless coverage blind spots in coal mines, including closed mine environments characteristics, common non-line-of-sight scenarios, and safety constraints on transmission power and antenna settings. However, traditional wireless coverage blind spot solutions for underground coal mines have limitations in hardware deployment, maintenance costs, and technical implementation. They cannot truly meet safe and efficient communication needs of specific mining scenarios. IRS has significant performance advantages in achieving coverage blind compensation due to its low cost, low power consumption, easy deployment, and scalability. This paper introduces IRS technology from three aspects: hardware structure, auxiliary channel model and typical application scenarios (precise positioning, signal and energy simultaneous transmission, UAV communication, edge computing and physical layer security). This paper proposes the use of IRS technology to optimize underground wireless blind spot coverage. By deploying IRS reasonably in coal mines, it reduces the absorption and scattering of main signal components by walls, and utilizes the adjustable reflection characteristics of IRS to optimize signal propagation. It significantly improves signal strength and coverage range. The future research directions of IRS technology in underground wireless communication in coal mines are pointed out. The directions include energy management of IRS-aided coverage and blind compensation systems, IRS-aided underground communication based on artificial intelligence, application of new IRS technology, and flexible deployment of IRS.

Aiming at the problems of insufficient curvature of the tooth profile of the wheel of the high reduction hypoid (HRH) gear, and high twist of the tooth surface of the pinion with a large helix angle, a method of using a tool to modify the wheel to realize the point contact of the tooth surface is proposed; the pinion adopts the general hobbing method, which simplifies the machining parameters of the machine tool. Three-dimensional models of wheels and pinions and Ease-off topological surfaces are established; the contact performance parameters of tooth surfaces, such as the contact path, differential curvatures, transmission error, etc. are analyzed. The contact areas of the tooth surface before and after modification are compared by 3D motion simulation，and the edge contact is avoided after modification, and the contact area is located in the middle of the tooth surface near the small end, which is consistent with the actual contact spot of the gear. The dynamic performance test of HRH gear reducers has been completed, the gear meshing transmission performance is excellent, and the meshing quality is stable, which verifies the reasonable control of the designed HRH gear modification amount, and the correct theoretical calculation and motion simulation.

To further understand the role of low-energy N+ implantation in the phylogenetic evolution and characterization of drug resistance in Escherichia coli (E.coli), this study used low-energy N+ ion implantation to screen for drug resistant E.coli. The 16S rRNA gene sequences were obtained through de novo genome sequencing, and the drug resistance characteristics of mutant strains were assessed using the K-B method. Twenty-five drug-resistant strains were obtained by mutagenesis. The 16S rRNA in five mutant strains had a point mutation (A257C) or a gene deletion in C1, V1, V2, V6-V9, and C6-C9 regions, respectively. GC content increased and the mutation rate reached 0.4%-0.6%. The results indicate that low-energy N+ ion implantation could trigger mutations and drive 16S rRNA gene evolution in E.coli., which could accelerate development of antibiotic resistance in E.coli.

Using S-band dual-polarization radar data and other observation data, a supercell storm that caused a large hail in Changsha, Hunan Province on 10 May, 2021 was analyzed. The results show as below. (1) This process takes place under the synoptic condition of low-level warm advection, high energy, and convective instability. Besides, wet bulb 0 ℃ (WBZ) is obviously lower than the height of 0℃, which provided favorable conditions for the formation and maintenance of large hail supercell storms. (2) The area of strong center (horizontal reflectivity (Zh) ≥60 dBz) and the maximum horizontal reflectivity increase significantly. The vertical integrated liquid water content increases significantly, and the height of mass center develops to reach the effective growth layer of hail, which can be used as a criterion of major hail formation and development. (3) The evolution of differential reflectivity (Zdr) column, correlation coefficient (CC), and specific differential phase (Kdp) provides the important basis for distinguishing the changes in the cloud physical process of hail. In the early stage of storm development, the appearance of Zdr column corresponds to the updraft zone, which extends above WBZ. The supercooled raindrops in the Zdr column provide hail embryos for the development of hail. The Zdr-hole (< 0 dB) corresponds to the downdraft area and expands to near the ground. Small CC and Kdp-hole indicate the appearance of dry large hail. (4) The dual-polarization monitoring and identification model of hail supercell is constructed and which shows that due to the occlusion of precipitation echo, Zh does not show the characteristics of three body scatter spike (TBSS). The polarization TBSS characteristics of significantly negative Zdr and small CC and non-uniform beam filling can be used as an important criteria for identifying hail and hail scales.

Because of mining activities, a large amount of mine water was pumped to the surface, caused serious waste of water resources and environmental pollution. This paper took samples of mine water from different sources in Zhangji Coal Mine of Huainan coalfield, and selected 7 ion contents of Ca2+, Mg2+, Na++K+, Cl−, SO4 2−, CO3 2−, HCO3 −, added pH, TDS, EC, TH to 11 chemical indexes as the basis of water quality detection. Then, the hydrochemical characteristics of mine water had been studied such as ion composition, dynamic change, correlation, afterwards, the water quality evaluation would been carried out. Finally, according to the relationship between sodium adsorption ratio (SAR) and EC, the risk levels of salinization and sodium toxicity of mine water in Zhangji Coal Mine were divided, and the ways of resource utilization of mine water in study area were determined. It is concluded that the TDS content of well water in Zhangji Coal Mine was 255.47-7 291.74 mg/L, with an average of 2 346.60 mg/L, which was seriously over standard. The highest contribution of TDS ion composition was Na+ and K+; The results of water quality classification showed that the proportion of mine well water of class V in the study area was as high as 81%; The relationship between sodium adsorption ratio (SAR) and EC showed that 79.3% of the water samples were distributed in S3-E4 AND S4-E4 areas. The mine water in Zhangji Coal Mine had high risk of salinization and sodium toxicity and was not suitable for agricultural use. The mine water area could only be used as general industrial water area, indirect contact entertainment water area or general landscape water area.

Due to several advantages of the Multi-Input Multi-Output (MIMO) system in terms of waveform, space diversity, and multiplexing, the MIMO Dual Function Radar and Communication (DFRC) system, which is responsible for target detection and securing the communication by sharing the software and hardware resources, has attracted great attention. This paper addresses the MIMO DFRC system based on permutation matrix modulation and proposes a DFRC signal matrix design method based on the Alternation Direction Method of Multipliers (ADMM). By maximizing the Peak Mainlobe to Sidelobe level Ratio (PMSR) of the beampattern with the constraints of the reference codebook for both users and eavesdroppers, the system guarantees excellent detection performance along with protecting the communication information from interception. Aiming at the communication demodulation of the permutation matrix, a permutation learning demodulation method based on the Alternating Direction Penalty Method (ADPM) is proposed to improve the demodulation efficiency of the co-use waveform. Numerical simulations verify the effectiveness of the proposed methods to achieve dual function, capable of realizing multiuser communication and deriving higher PMSR compared with the existing counterparts.

Human milk, which provides personalized, comprehensive, and balanced nutrients, and immune protection, is the best nutritional source for 0~6 month-old infants, and it is the gold standard for infant food. A cohort study of human milk omics is a necessary prerequisite for comprehensively analyzing the composition and characteristics of Chinese human milk, establishing Chinese infant food norms and standards, developing infant nutrition guidelines, and creating infant foods. This article presents the research progress of the National Engineering Research Center of Dairy Health for Maternal and Child pertaining to the China Maternal and Infant Nutrition Health Birth Cohort Study (MINC) in terms of breast milk lipidomics, glycomics, proteomics, and microbiomics detection techniques, composition characteristics, differences from bovine milk, and industrial applications in infant food. This will lay a science and technical support for the omics research of Chinese human milk and provide the necessary data and demonstration for industrial application.

There were two rare 6 cm hailstones under the background of low-level warm advection forcing in Huaihua of Hunan Province on March 21 and May 4, 2020. Based on the meteorological stational data and the Doppler weather radar data, the structures of intensity and dynamic fields of the supercell storms for these two events are analyzed. Results are showed below. (1) Both cases occur under the background of low-level warm advection forcing. Moderate-intensity convective effective potential energy, large deep vertical wind shear, and high energy helicity favored the organizational development and maintenance of storms, and the ground convergence line is the main trigger factor of severe convection weather. (2) The 6-cm hails in the two cases both occurred in the early mature stage of supercell storm, which are caused by the "supercell-like" storm without the characteristics of mesocyclone, but with the characteristics of hook echoes, sidelobe echoes, three-body scattering spike, and echo overhangs. (3) In the intense development stage, the vertical dynamic fields of the storms are both featured by the structure of low-level convergence, the double-vortex-tube rotating structure of cyclonic rotation and anticyclonic rotation in the middle level (referred to as double vortex) and high-level divergence. (4) The maximum reflectivity and the cells-vertical integrated liquid both reach 67 dBz and 69 kg·m-2.The decrease of height top and the strongest-shear height reflect hail falling.

Dense-repeated jamming is highly related to the radar-transmitted signal, and it has suppression and deception jamming effects, which makes detecting the real target difficult for a radar system and seriously threatens the operational capability of radar. To solve this problem, an intelligent suppression method based on the Support Vector Machine (SVM) is proposed in this paper. The optimal SVM model is obtained through offline training on a random sample set to intelligently identify and classify targets and interference. Then, the interference sidelobe in the target range unit is further suppressed by smoothing filtering. Finally, high-resolution two-dimensional reconstruction is performed based on Compress Sensing (CS) theory to estimate the target parameter information. Simulation experiments and measured data processing results reveal that the proposed algorithm can effectively suppress dense-repeated jamming and accurately detect real targets in different scenarios.

In recent years, environmental problems have been a hot topic of social concern, such as heavy metal pollution in the atmosphere, soil and sediment, which are closely related to our life.To solve the heavy metal pollution in environment, the key is to determine the source of pollution.With the rapid development of stable isotope tracer technology, further achievements have been made in the study of the traceability of heavy metal pollution. Meanwhile, isotope tracer technology has become an important means in the traceability of heavy metal pollution.To better understand the isotope tracer technology application in environmental pollution sourcing, having the copper isotope as an example, the basic properties of copper, isotope fractionation in the geochemical process, processing and purification different types of samples, isotope analyze technique, tracer technique, the meta model has carried on the brief summary.This paper further describes the end members(natural input source and artificial input source), pollution path and pollution degreeof river pollution, smelter pollution and atmospheric particulate pollution. Finally, the application of isotope tracer is summarized and prospected.

Objective To observe the regulation of miR-504 in mouse models and the biological behavior of breast cancer cells, find the key target genes of miR-504 in the regulation process, and explore the working mechanism of miR-504 in breast cancer. Methods A mouse model of breast cancer was established and the effect of miR-504 on tumor growth was observed. Target genes of miR-504 were screened by Target Scaning and confirmed by double luciferase reporter gene assay. RT-qPCR and Western blot were used to detect proteasome activator complex subunit 3(PSME3) expression in breast cancer and adjacent tissues. The effects of miR-504 and PSME3 on proliferation, cycle and migration of human breast cancer cell line MCF-7 were determined by CCK8 assay, flow cytometry and Transwell assay. Results It was found that miR-504 inhibited tumor growth in nude mouse xenograft model of breast cancer(PPSME3 was a target gene of miR-504, and its expression in breast cancer tissues was significantly increased. Up-regulation of miR-504 expression could inhibit the expression of PSME3 (PPConclusions miR-504 may play an anti-cancer role in breast cancer by targeting PSME3 regulation.

The Namjag Barwa syntaxis is in the eastern Himalayan syntaxis area with the most intensive neotectonic activity. There are many late Quaternary active fault belts and strong seismicities. The tectonic stability of these active fault belts, such as the Jiali, Dongjiu-Milin, and Motuo fault belts, may influence the project's construction. In-situ stress is a critical parameter for estimating regional tectonic stability. Currently, there is a lack of abundant in-situ stress results about the Namjag Barwa syntaxis. It is challenging to assess geological safety risks for major projects. Based on focal mechanism solutions, the paper reveals the orientation of the maximum principal stress surrounding the Namjag Barwa syntaxis using the stress tensor inversion method. According to the critical condition of fault instability, the magnitudes of principal stresses around the Namjag Barwa syntaxis are also estimated by combining the inversion of the stress shape ratio and the frictional coefficient. The results indicate that the maximum principal stress direction in the Namjag Barwa syntaxis area is NE-NNE. The maximum and minimum horizontal principal stresses increase linearly with depth at a gradient of 0.032~0.0355 MPa/m and 0.0227~0.0236 MPa/m, respectively. Heterogeneous features of the in-situ stress field still exist. Generally, the results estimated in this study are in good concordance with the in-situ stress measurements. They can provide reliable in-situ stress parameters for evaluating the tectonic stability in the Namcha Barwa region.

Background and purpose: Exosomes are important messengers that mediate the crosstalk between cancer cells and recipient cells in the tumor microenvironment; however, the role of extracellular exosomal long non-coding RNA (lncRNA) in the cell-cell communications of glioma stem cells (GSCs) and glioma cells remains unclear. This study investigated the effects of exosome-derived lncRNAs on proliferation, migration, invasion and stemness in glioma. Methods: The datasets containing low-grade glioma (LGG) and high-grade glioma (HGG) lncRNA expression data were downloaded from the Chinese Glioma Genome Atlas (CGGA) and the Cancer Genome Atlas (TCGA) databases. Differentially expressed lncRNA (DelncRNA) between LGG and HGG tissues was identified, and the relationship between HOXA-AS2 levels and overall survival (OS) of glioma patients was analyzed. GSCs were isolated from human glioma cell line SHG44, and CD133+ enriched cells were detected by flow cytometry. The expression levels of stem cell-related proteins (CD133, SOX2 and OCT4) were detected by Western blot. Exosomes derived from SHG44-GSCs were extracted and identified, and labeled with PKH26 cell membrane dye. Then SHG44-GSCs transfected with Cy3-labeled HOXA-AS2 were indirectly co-cultured with SHG44 cells. The levels of HOXA-AS2 in SHG44-GSCs and SHG44-GSC-derived exosomes were detected by real-time fluorescence quantitative polymerase chain reaction (RTFQ-PCR). The plVX-IRES-PURO HOXA-AS2 lentivirus plasmid and lentivirus shRNA containing targeting HOXA-AS2 plasmid were used for lentivirus transfection. The effect of HOXA-AS2 derived from SHG44-GSC on the proliferation and invasion of SHG44 cells was detected by cell counting kit-8 (CCK-8) and transwell assays. Results:HOXA-AS2 was highly expressed in gliomas, and was associated with worse OS in patients (P

Alzheimer’s disease is known as one of the “top ten killers in the world”. Due to lack of effective therapy at present， early pathological changes have captivated widespread attention. Axonal transport dysfunction has been reported as an early pathological feature of many neurodegenerative diseases. However， multiple factors can cause axonal transport dysfunction. In this article， the relationship between axonal transport dysfunction caused by kinesins， microtubules and mitochondria and Alzheimer’s disease was discussed， aiming to provide new ideas for the prevention and treatment of Alzheimer’s disease by in-depth study on axonal transport mechanism of neure.

The characteristics of anonymous communication, such as difficulty in node discovery, service positio-ning, communication relationship confirmation, and user monitoring, make the darknet built on it full of various illegal and criminal activities of anonymous abuse. To this end, the academic community has carried out a series of targeted research around anonymous communication and darknet. Accordingly, on the basis of systematically intro-ducing the development history of anonymous communication, anonymous mechanisms and typical systems, this paper focuses on combing, summarizing and inducing related research in this field by combining key technologies of anonymous communication, anonymity measurement, anonymous attack, anonymous enhancement, anonymous communication performance evaluation and improvement and darknet space comprehensive governance. Mean-while, this paper focuses and analyzes the development trend of anonymous communication research in the future and the challenges and countermeasures faced by the darknet space comprehensive governance.

In recent years, the corona virus disease 2019 (COVID-19) pandemic has had a huge impact on the global medical, political and economic fields. Since the beginning of the COVID-19 epidemic, our understanding of the impact of COVID-19 has grown exponentially. Recently, the COVID-19 epidemic has changed rapidly in China, and there has been controversy over how to carry out surgical operations for patients with lung neoplastic lesions. Some studies have shown that lung cancer patients undergoing surgery are more likely to experience respiratory failure and perioperative death after contracting COVID-19 than the general population, however, delays in cancer treatment are also associated with increased mortality among these patients. In particular, the novel coronavirus Omikron variant has a higher transmissibility and may escape the immunity obtained through the previous novel coronavirus infection and vaccination. In order to minimize the risk of novel coronavirus infection in surgical patients, it is necessary to develop new treatment guidelines, expert consensus and preventive measures. However, the current rapid change of the epidemic situation has led to insufficient time and evidence to develop guidelines and consensus. Therefore, thoracic surgeons need to evaluate specific patient populations at higher risk of severe complications before surgery and weigh the benefit of surgical treatment against the risk of novel coronavirus infection. We try to give some recommendations on lung surgery during the current domestic epidemic situation based on the guidelines and consensus of oncology and thoracic surgery organizations in different regions on lung surgery.

In order to study the role of alloying element Mo in the Fe-Cr-B wear-resistant surfacing alloy,plasma arc welding surfacing was used to prepare Fe-Cr-B wear-resistant surfacing alloy layer with different Mo contents on the surface of Q235 by adjusting the amount of molybdenum iron powder in the surfacing alloy powder.Scanning electron microscopy,XRD and other analysis and testing methods were used to study the effect of the change of Mo content on the microstructure and properties of Fe-Cr-B surfacing alloy.Results showed that when no molybdenum iron powder was added into the surfacing alloy,the surfacing alloy consisted of M2B and (Fe,Cr) phases.When the content of Mo in the surfacing alloy reached 2% (mass fraction),a new phase FeMo2B2 precipitated in the surfacing alloy.In such case,the surfacing alloy consisted of M2B,FeMo2B2 and (Fe,Cr) phases;and the Rockwell hardness of the surfacing alloy depended on the volume fractions of M2B,FeMo2B2 and (Fe,Cr).With the increase of Mo content,the Rockwell hardness and wear resistance of the surfacing alloy gradually increased.Compared with the surfacing alloy without Mo,the wear resistance of surfacing alloy with 8% (mass fraction) Mo was improved by 1.2 times.

Major depressive disorder is a serious disease that impacts human health worldwide. Traditional antidepressant medications are limited by the delayed onset of therapeutic effects and the unacceptable side effects. Recently, the rapid antidepressant effect of ketamine, which decreases depressive symptoms within hours, has been a very attractive finding in the field, but the underlying mechanisms mediating this rapid response remain unclear. Besides, the clinical application of ketamine still carries risks, such as addiction and deleterious side effects. In May 2022, Rawat et al. reported that the acute activation of adult-born immature granule neurons (ABINs) in the dentate gyrus played a key role in the rapid antidepressant effects of ketamine. This commentary reviews the important findings of this research and looks forward to the future work.