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Oxygen supply and bacterial viability are crucial for efficient calcium carbonate precipitation in concrete crack healing processes. However, the open deliverance of oxygen-releasing compounds (ORCs) and bacterial spores during concrete mixing and casting poses a threat to spore viability and limits oxygen availability. To address these challenges, we developed an innovative approach integrating an oxygen self-supply strategy with bacterial strain B6. As such, B6 spores, along with Ca(OH)2 and CaO2 as oxygen sources and essential nutrients, were embedded within cement-shell microcapsules to build a microbial self-healing system. The result shows that in the presence of oxygen source and nutrients, B6 group (BPN) exhibits successful crack repair, achieving a repair ratio of approximately 100% after 30 days, while other control groups show less effective repair rates (20–60%). Moreover, water permeability significantly improves in the BPN specimens after crack repair, reaching 0 ml/cm−2·min, highlighting the efficacy of the developed self-healing system. Encapsulating the healing agent within cement shell effectively mitigates the reactivity between ORCs (CaO2) and water, thereby facilitating stable oxygen supply and safe delivery of microbial agents during crack healing. Furthermore, in-situ micromorphology and composition identification of crack repair materials affirm the presence of calcium carbonate precipitation to seal the concrete cracks. The encapsulation of healing material within cement shell stands out as an innovative approach, demonstrating an efficient self-healing process of concrete cracks. These findings might unveil new possibilities for bio-concrete to be used in sustainable and resilient construction practices, particularly in environments prone to cracking and water ingress.

Objective Hydrogen energy becomes one of the solutions for energy transition in rail transit due to its characteristics such as abundant reserves, ecological friendliness, and efficient transition. At the initial stage of hydrogen energy application in rail transit vehicles, it is necessary to analyze the existing research status and put forward application suggestion. Method The application background and characteristics of hydrogen energy are described, and the application status of hydrogen energy in rail transit vehicles at home and abroad is introduced. On this basis, the key technical challenges of hydrogen energy application in the field of rail transit are extracted, and their research status is analyzed. Then, according to the application and research status, the urgent problems to be solved and overcome in the application of hydrogen energy in the field of rail transit are summarized, and relevant suggestions are put forward. Result & Conclusion Driven by both the application promotion and the technological innovation, hydrogen energy has a broad application prospect in the field of rail transit. The industrial policy, standard system and application technology should be continuously promoted for the further application of hydrogen energy in rail transit field, helping energy transition in rail transit.

ObjectiveTo understand the utilization of preconception healthcare services and the influencing factors among the women expecting additional childbirth in Jiading District, Shanghai, and to provide references for promoting the utilization of preconception healthcare services under the new population policy.MethodsA questionnaire survey on the utilization of preconception healthcare services and related influencing factors was carried out among 682 women expecting additional childbirth across six subdistricts in Jiading District, Shanghai. The results were statistically analyzed.ResultsThe average age of the women was (31.7±4.5) years, 30.2% of whom were ≥35 years old. The proportion of women having their third or subsequent children was low, at 16.4%. A significant majority, 92.4%, were found to have various risk factors during initial pregnancy screening. The utilization rate of preconception healthcare services among women seeking additional childbirth was relatively low at 26.7%. Awareness of the free preconception check-up program in Jiading District was also low at 28.6%, and the utilization rate for these services was even lower at 7.69%. Unplanned pregnancies were the primary reason for not utilizing preconception healthcare services, accounting for 63.6%. The results of multifactorial binary logistic regression analysis showed that the utilization rate of preconception healthcare services before the current pregnancy was higher for women aged between 35 and 39 compared to women aged ≤29 years old (OR=1.789, 95%CI: 1.033‒3.099). Women with planned pregnancies had a higher utilization of preconception healthcare services prior to this pregnancy (OR=4.164, 95%CI: 2.627‒6.602). Women who had received preconception care prior to their first birth had a higher utilization rate of preconception care prior to the current pregnancy (OR=7.534, 95%CI: 4.954‒11.456). Women without a family history of chronic diseases had a higher utilization rate of preconception healthcare services (OR=1.903, 95%CI: 1.083‒3.345).ConclusionUnder the context of three-child policy, the proportion of women seeking three or more children in Jiading District is low. Most of these women have risk factors identified during initial pregnancy screenings. The utilization rate of preconception healthcare services and the awareness of the free preconception screening program in Jiading District are both low. Unplanned pregnancies remain the primary reason for failing to receive timely preconception healthcare services. Age, whether the pregnancy was planned, whether the women had received preconception healthcare services before their first baby and family history of chronic diseases are the main factors affecting the utilization of preconception healthcare services. Relevant departments should enhance the promotion of preconception healthcare service programs, especially for women of childbearing age who have not yet given birth, so as to improve the utilization rate of preconception health care services.

The coaching program with outstanding achievements has indeed been implemented based on the objectives of the coaching itself and the critical factors contained in a program. Factors from an organizational system that is not good can also affect achievement results. With appropriate stages and fulfilling these factors, it is hoped that achievement will be more easily achieved. Looking at the introduction above, it is clear that Indonesian floorball still has many obstacles in its sports management system. Still needs to be developed in all regions of Indonesia. Besides that, Indonesian floorball athletes' performance is considered less able to match Asian countries. Hence, this study aims to evaluate the sports organization system and the implementation of floorball athletes in the Indonesian Floorball Association. The objects of this research include the Chairperson of Floorball at the central and regional levels, the Secretary, the Treasurer, the Coach, and 96 athletes who competed in the big eight rounds of the national floorball championship in Jakarta. Data was collected using the mixed method by administering a CIPP questionnaire and giving physical test items to floorball athletes. The output of this research is an evaluation of the sports organization system in which policymakers can improve and create a good formula so that the future organization can be better so that floorball athletes' achievements can increase.

AIM: To compare the binocular and monocular accommodation among normal group, premyopia group and mild myopia group, and to study the characteristics of accommodation in the premyopia group, thus providing clinical evidence for the delay/prevention of myopia and the effective decrease of the incidence of myopia.METHODS: Cross-sectional descriptive study. A total of 179 children who had abnormal/high-risk visual acuity indicated by the vision screening in school from October 2021 to February 2023 were selected, including 92 males and 87 females, aged from 6 to 12(mean 8.55±1.66)years old, then they were referred to the Juvenile Myopia Prevention and Control Center in Cuizu Community Health Service Center. They were divided into normal group(+0.75 D0.05). Monocular AF had significance between the normal group and the premyopia group(P0.05); The monocular AA had significance among the three groups(P

Underground gas storage plays an important role in the strategic reserve, peak shaving and stable supply of natural gas. Due to the complex geological conditions in China, very limited sites are available for the construction of gas storage. Thus, it is a good choice to build gas storage in the abandoned coal mine with rich resources. For this purpose, it is particularly important to establish an evaluation method for abandoned coal mine type gas storage. Hence, the factors affecting the conversion of abandoned coal mines into gas storage were summarized and analyzed based on the research results of gas storage site selection at home and abroad from the five aspects of hydrogeology, caprock tightness, geologic structure, influencing factors of abandoned coal mine, and other safe and economic factors. Then, a fuzzy comprehensive evaluation model based on hierarchical analysis was established and a comprehensive evaluation table of storage sites was prepared to evaluate the sites of abandoned coal mines. Besides, the evaluation model was applied to the site evaluation of a coal mine in Shaanxi. The evaluation results show that the coal mine is at an excellent grade and has the potential to be transformed into gas storage. Generally, the evaluation method has certain guiding implications for China to develop abandoned coal mine type gas storage.

ObjectiveTo investigate the impact of edible vegetable varieties， temperatures， and inoculation sites on the survival of Listeria monocytogenes （L. monocytogenes）， providing a theoretical foundation for risk assessment and key control measures of L. monocytogenes in edible vegetables.MethodsFreeze-dried quantitative L. monocytogenes served as the strain source， with the surfaces and sections of five edible vegetables （colored pepper， onion， cucumber， virgin fruit and lettuce） used as inoculation sites. The strain was cultured at both 4 ℃ and 25 ℃ for 7 days. Regular monitoring of the L. monocytogenes quantity in each sample was conducted， and growth was analyzed.ResultsThe quantity of L. monocytogenes freeze-dried in different bottles was uniform （F=1.923， P

Quasi-static axial compression experiments were conducted on the composite thin-walled C-channels with different flange widths. The axial compression failure modes and failure mechanisms were analyzed through CT scanning，and the effects of different flange widths on the axial compression energy-absorption characteristics of C-channels were evaluated by using the energy-absorption indexes. The single-layer shell model and multi-layer shell model of composite C-channel were established，and the finite element models were verified by comparing the failure modes，load-displacement curves and energy-absorption indexes. The results show that the flange width has a significant effect on the axial compression failure modes and energy-absorption characteristics of C-channels. The C-channels with flange widths of 25 mm and 30 mm are failed in the stable and asymptotic manner under the axial compression loads and have good energy-absorption characteristics. The deviation of mean crushing force，energy absorption and specific energy absorption obtained by the multi-layer shell model is within 5%，while that obtained by the single-layer shell model is within 8%，which indicating that the multi-layer shell model of C-channel has the higher simulation accuracy.

Association standardization of oil and gas pipeline network in China has been in progress for quite a period. However, it is urgent to further accelerate its standardized and high-quality development facing the new requirements, such as high-quality development of the industry, autonomy enhancement, extensive international oil and gas cooperation, etc. In attempt to assist achieving the goal, this research analyzed the data pertaining to association standards for oil and gas pipeline network published in China, focusing on its quantitative change, subject content, field distribution, and drafting units, and employed a complex network algorithm to illustrate the present state of association standardization efforts with a diagram. Based on the aforementioned work, this research found out that there are three main operational modes for association standards organizations, that is professional organizations in this field being totally committed, organizations in relevant field being largely involved and others participating occasionally. The analysis results demonstrate that many problems exist in current association standardization work of oil and gas pipeline network, such as lacking of energy and systematic planning, insufficient in the number of standards, especially of high-quality standards, and the implementation of supervision by industry authorities. The research, in dealing with these problems, promoted several countermeasures, including(1) to establish a correct recognition of the importance of association standardization;(2) to build a national organization to promote coordinated development;(3) leveraging the role of Pipe China to promote openness and integration;(4) to develop a multi-level working mechanism to improve the overall quality; and(5) to refine the responsibilities of the supervising authorities to facilitate high-quality development, etc.

A method for measuring the docking pose of large components based on the draw-wire displacement sensor is proposed. In this method, coordinate systems and measurement points are established on the docking surfaces of fixed and moving components. The draw-wire displacement sensor is used to measure the distances between these measurement points. A mathematical model based on the distances between the measurement points is established, and the three-sphere rendezvous positioning principle is optimized to obtain the spatial positions of the measurement points. Consequently, the pose deviations of the fixed and moving components in all six degrees of freedom (6DOF) are determined. A simulation analysis of the measurement uncertainty of the obtained pose deviations is performed, resulting in a composite standard uncertainty obtained from the measurement standard uncertainties of different sensors. The simulation results show that the composite standard uncertainty is most affected in the x-axis translation direction and least affected in the x-axis rotation direction. With this method, only the distances between the measurement points need to be measured to determine the corresponding pose relationships. The cost of the equipment is low, and it is not easily affected by external factors such as the environment.

Lift capacity is the key performance of the launch vehicle, and high chemical energy bi-propellants are commonly used for the modern large liquid rockets. The residual unburned propellant has a strong effect on the lift capacity and the lift efficiency, especially for the orbital stages. In this paper, the bias residual control of high mixture ratio propellant is studied, three models, including equal-probability depletion model (EPDM), equal-mass residual model(EMRM) and optimum residual model(ORM) are analyzed. Comparing with the traditional equal-probability depletion, the bias residual control of bi-propellants, especially for LOX and LH2, is benefit to the lift capacity. The effect between EMRM and ORM on the residual unburned propellant is negligible, and the EMRM is preferred in engineering.

As knowledge information becomes specialized, segmented, and complex, the construction of knowledge systems in the field of education management in colleges and universities becomes more and more difficult. The article extracts the knowledge in the field of education management through the entity relationship extraction model based on a convolutional neural network and then systematizes and summarizes the knowledge of education management by the knowledge network theory method to further build the framework of education management knowledge system. The centrality of the knowledge points in the education management system is calculated by the mediated centrality method and Dijkstra’s algorithm centrality calculation method, in which the centrality of the knowledge point k5 is the largest at 6.34. In the statistical analysis of high-frequency words in the knowledge system of education management, the vocabulary in the statistical table reaches the total number of 5,600 times, and the selected high-frequency words are able to reflect the main direction of the education management, which verifies the rationality of the knowledge system of education management proposed in this paper. The rationality of the proposed knowledge system for educational management.

In order to meet the changing educational needs, this paper collects the factors related to the teaching mode through the method of multilevel fuzzy evaluation and establishes a multilevel fuzzy evaluation system including the factors of teaching methods, textbook selection, learning resources and so on. To obtain quantitative satisfaction results, fuzzy numbers are employed to calculate the satisfaction evaluation of teaching programs. Establish a judgment matrix using triangular fuzzy numbers and hierarchical analysis to assign weights to different indicators. The evaluation results of each factor are synthesized to obtain the evaluation results for the timeliness of the English teaching method. The results show that although there is not much difference in the basic level of English between the experimental class and the control class, the experimental class, after using the method of this paper, has a measure of qualitative data higher than the standardized metric of 71.195, and the academic grade reaches a full score of 10. It is further verified that by using the method based on multilevel fuzzy evaluation, universities can optimize their teaching mode in a more targeted way to adapt to the increasingly changing educational environment.

With the development of aircraft demand, and emerging of new material and new process, the test and validation technology of aircraft structure strength will also face new challenges. As the key measures of networking and intelligentization, 5G technology will promote the innovation and reform of strength test technology effectively. Firstly, the present situation and development trend of structural strength test technology for full-scale aircraft is introduced briefly, and one new idea of structure strength test for full-scale aircraft based on 5G technology is proposed through the research of the demand of full-scale aircraft strength test. Secondly, the incidence matrix of test and 5G technology is formulated through the analysis of advantages and features of 5G technology for strength test of aircraft, the typical test scenarios based on 5G technology are planned. Finally, the development and application of inspection and monitor system based on 5G technology is carried out for fatigue test of an aircraft. The results show that the intelligent facilities based on 5G technology can improve the level of test significantly, which is of important significance for intelligentization of test.

To study the stability of the over-pressure reinforcement effect of the copper tube at room temperature, the burst tests for the small diameter soft TP2 copper tube at room temperature during the natural aging time of 0, 6, 12 and 24 months were carried out respectively. These results indicated that: the mean of the measured burst pressure did not change significantly for small diameter soft TP2 copper bare tube and rifled tube at the same pretreatment pressure during the natural aging time of 0, 6, 12 and 24 months, respectively. The standard deviation was gradually smaller and the over-pressure strengthening effect was obvious. The measured burst pressure was different obviously for small diameter soft TP2 copper tube at the pretreatment pressure was 4.60 MPa and 16.50 MPa respectively during the same natural aging time, the mean was significantly larger and standard deviation was significantly smaller for measured burst pressure with the increase of pretreatment pressure, the results showed that pretreatment pressure had a great influence on strengthening effect, and higher pretreatment pressure could get better strengthening effect. The burst pressure conforms to the normal distribution for the same small diameter soft TP2 copper tube at the same over-pressure reinforcement during the natural aging time shall not exceed 24 months. Over-pressure reinforcement at room temperature was a suitable method to increase burst pressure of soft TP2 copper tube, and the method could be used in engineering.

Based on the job demands-resources model, the mechanism and boundary conditions of leader-member exchange social comparison on employee innovative behaviors were tested with self-efficacy and role load as mediating variables and error management climate as moderating variables. Based on the empirical analysis of 452 questionnaire data collected in two stages, it is found that self-efficacy and role load play a partial mediating role in the relationship between leader-member exchange social comparison and employee innovative behavior. Error management climate positively moderates the relationship between leader-member exchange social comparison and self-efficacy, and positively moderates the mediating role of self-efficacy in the relationship between leader-member exchange social comparison and employee innovative behavior. Error management climate negatively moderates the relationship between leader-member exchange social comparison and role load, and negatively moderates the mediating role of role load in the relationship between leader-member exchange social comparison and employee innovative behavior.

Particle therapy utilizes high-energy protons and carbon ions to treat patients, leveraging their unique Bragg peak and superior relative biological effectiveness. This treatment modality shows great promise in improving disease cure rates and minimizing treatment side effects. However, its adoption in China is limited by the high cost associated with this advanced radiotherapy technique, highlighting a substantial demand for particle therapy equipment in the country. This report conducts a comparative analysis of cyclotron and synchrotron accelerators, prevalent in clinical particle therapy institutes. We examine their beam parameters and provide detailed insights into the techniques and functionalities associated with each accelerator type. Specifically, we elucidate the processes of beam injection, acceleration, and extraction, highlighting operational intricacies at each phase of the cycle. Furthermore, we present beam intensity and energy modulation for both accelerators in three-dimensional dose delivery. In summary, the synchrotron offers adjustable energy levels and the ability to produce high-energy multi-ions, while maintaining a high beam transmission rate. Conversely, the cyclotron provides continuous beams with rapid intensity modulation and an energy degrader on the beam transport line for energy variation, leading to activation near the degrader. Therefore, when selecting the most suitable accelerator for clinical institutes, factors such as cost, maintenance requirements, treatment efficiency, and clinical needs must be carefully considered.

In China, tight sandstone gas reservoirs are widely distributed, yet their development is hindered by issues such as low extraction efficiency and a monotonous extraction approach. To enhance the efficiency of tight sandstone gas extraction, this study investigates the internal fracture network characteristics of sandstone and its correlation with chemical solutions. Employing the sandstone acid fracturing technique, an experimental setup under gravitational conditions is established. Through this apparatus, fracturing experiments are primarily conducted on rocks utilizing the acid fracturing technique. The experimental findings suggest that the acid-fracturing coupling approach effectively induces rock fracturing. Uniaxial compression tests also indicate a noticeable alteration in the elastic-plastic behavior of rock samples after chemical solution corrosion, becoming more pronounced with increasing duration. The research demonstrates that this experimental setup significantly enhances the fracturing of sandstone and consequently improves the extraction of tight sandstone gas, holding crucial reference value.

Objective To investigate the efficacy of a holistic approach for postoperative pain management in children receiving dental treatment under general anesthesia in day-surgery operating room. Methods A total of 120 children, aged 3-7 years, of American Society of Anesthesiologists physical status Ⅰ or Ⅱ, with ≥ 10 treated teeth, receiving comprehensive dental treatment under general anesthesia from January 2020 to August 2020 were enrolled in this trial and randomly allocated into the holistic approach group (group H, n=60) and including preemptive analgesia, instructions to parents for pain management and web-based assessment system (assessment pain by scanning the quick response code 4, 6, and 24 hours postoperatively) and the control group (group C, n=60) only scanning the quick response code. Pain, face, legs, activity, cry and consolability (FLACC) scale was used to assess the level of pain 2 h postoperatively and the parents postoperative pain measure (PPPM) was used to assess the level of pain 4, 6, and 24 h postoperatively in two groups. Results The FLACC scores of group H 2 h postoperatively were significantly lower than group C (P

Mixing and homogenization in anaerobic digesters are affected by the flow curve of sludge. The aim of this study is to mathematically express the flow curve of dense anaerobically digested sludge behaving as thixotropic and pseudoplastic fluids. Time-dependent changes in two pseudoplastic parameters, i.e., consistency index (µ p) and pseudoplastic index (n), by shear are modeled using a second-order kinetic equation with a coefficient that includes the power function of the shear strain rate. The calculated results are consistent with the experimental results. The kinetic parameters that yielded the ultimate values after shearing were associated with the sludge concentration, unlike the other kinetic parameters.

High myopia is a common ocular genetic disease in the world. The study sought to investigate the effect of the Insulin-like growth factor-1 (IGF-1) and Matrix metalloproteinase-9 (MMP-9) genes polymorphisms on high myopia in a Han population of China. This study recruited 216 unrelated Han Chinese subjects, including 103 cases with high myopia and 113 controls. Four tagging single nucleotide polymorphisms (SNPs) of IGF-1 and MMP-9 genes were genotyped using the Sequenom MassARRAY method. The chi-square test showed that the family history was significantly correlated with myopia. The SNP genotypes were all in Hardy–Weinberg equilibrium (P > 0.05). Among the four SNPs, there were statistically significant differences in the genotype and allele frequencies of rs2236416 between the groups (P = 0.024). The significant associations of rs2236416 between cases and controls also appeared after Bonferroni multiple correction (P = 0.024). Then, there were significant differences in the genotypes dominant model and codominant model of rs2236416 between groups (P = 0.007 and P = 0.004, respectively). rs5742632 showed a significant difference between the cases and the controls in the recessive model (P = 0.037). Our findings indicated that rs2236416 of MMP-9 was associated with myopia in the population. The result suggested MMP-9 gene locus may play a role in myopia.

Two novel nonpneumatic tires named Tweel-2, designed based on the commercial Tweel model, and Saddle with hyperbolic paraboloid spokes are proposed in this study. Four nonpneumatic tire samples were successfully prepared with the 3D printing technology to measure and analyze and compare their properties. The results of quasi-static compression experiments showed that with the same relative density, the vertical bearing capacity of Tweel-2 tire was 1.4 times that of Tweel tire, while the vertical bearing capacity of the saddle tire was 4 times and 2.4 times that of Tweel and honeycomb tires, respectively. The finite element simulation method was used to explore the mechanism of improvement in vertical bearing capacity and energy absorption of the Tweel-2 and saddle design. The so-called circumferential unit in Tweel-2 and honeycomb tires enhances the deformation coordination between the spokes of Tweel-2 and increases the critical bearing capacity of the spokes by shortening the length of the deformation zone, so that more external work can be consumed under the same vertical deformation. The spatial configuration of the hyperbolic paraboloid can optimize the spatial stress distribution of the saddle tire and makes sure that a bigger amount of material deforms and participates in energy absorption, thus improving the overall strain energy level of the spokes.

It is essential to analyze the dynamic characteristics of regional groundwater levels and their driving factors for the rational development of groundwater in irrigated areas. This article explores the spatial distribution characteristics of the amplitude of groundwater level change in the Shihezi irrigated area by using the ArcGIS interpolation method and contrast coefficient variance method and analyzes the influence factors of dynamic change of groundwater levels by integrating the grey relational degree and path analysis methods and obtaining the sensitivity of each influencing factor to changes in groundwater levels and the relative importance of the influencing factors. The following results are obtained: (1) the groundwater level of the Shihezi irrigated area showed an overall increasing trend from 2012 to 2019, with a fluctuation range of 12.26–14.14 m. The groundwater level in the southeast of the irrigated area showed an upward trend, while the groundwater level in the northwest area showed a downward trend. (2) The groundwater level in the irrigated area first increased, then decreased, and then increased again. The variance of the contrast coefficient in the irrigated area ranged from 0.04 to 11.31, and the fluctuation range of the groundwater level in the central area was higher than that in the northern and southern areas. (3) The irrigated area of cultivated land and evaporation are the main factors affecting groundwater level change in the Shihezi irrigated area. The grey relation analysis shows that the irrigated area of cultivated land has the highest grey correlation degree with the evolution of the groundwater level, which is 0.947, and the average grey correlation index is between 0.74 and 0.95. Path analysis showed that the irrigated area of cultivated land, surface water usage, and evaporation were the main factors affecting groundwater levels. Human activities are one of the main driving forces of groundwater level change, and the research results provide a theoretical basis for the rational utilization and sustainable development of groundwater resources in the Shihezi irrigation area.

ObjectiveTo analyze the risk of food additives in Hubei Province, provide a basis for relevant departments to formulate management measures, and reduce the potential risk.MethodsIn the paper, the crystal ball software and Monte Carlo simulation method were used to evaluate the average daily exposure and risk probability of sodium cyclamate and acesulfame in foods in Hubei Province.ResultsThe average daily exposure and risk entropy of sodium cyclamate in pickled vegetable products were the highest, which were 3.98E-4 g/kg BW/d and 0.0372, respectively. In addition, there are significant differences in the risk probability of additives in different foods. The risk probability ranking of acesulfame in foods was pickled vegetable products > canned > beverage > pastry, and that of sodium cyclamate was pickled products > beverage > pastry > canned food.ConclusionThe health risk of residents in Hubei Province who ingest two sweeteners through diet was generally low, and the risk of sodium cyclamate was slightly higher than that of acesulfame, both at an acceptable level.

In order to investigate the mechanical properties of Zhanjiang structured clay in the three-dimensional stress state and the influence of structure on its strength criterion, a series of undrained true triaxial tests of different intermediate principal stress ratios, b-values, with equal mean principal stress, p-values, and undrained plane strain tests was carried out. The results are as follows. When p is less than or greater than the yield stress of the structure, the q- curves are strain softening and mild strain hardening type in general. The q- curves of true triaxial tests with different b-values are similar in shape. As b-value increases, the large principal strain corresponding to the q peak point shows the decreasing trend. Under different b-values, the effective cohesion decreases with increasing b-values, while the effective friction angle increases with increasing b-values. The effective cohesion and friction angle for the plane strain compression tests are between the effective cohesion and friction angle corresponding to b=0.25 and b=0.50. Influenced by the structure of clay, the strength criterion on π plane is applicable to the Lade-Duncan criterion when p-values are less than the yield stress of structure, while it is more applicable to the generalized nonlinear strength theory based on Mises criterion and Lade-Duncan criterion when p-values are greater than the yield stress of structure. For plane strain tests, the b-values of Zhanjiang clay under plane strain loading and unloading conditions are between 0.18 and 0.29 at failure, and the strength at failure can be approximated by the generalized plane strain strength criterion based on the general Mises and Lade-Duncan plane strain strength criterion.

BACKGROUND The south of Jiangxi Province is a typical geographical distribution area of selenium deficiency. However, some research results in recent years indicate that the rice has high selenium content. The reasons for inconsistency about selenium enrichment between soil and rice is still not clear. It is important to discuss the characteristics of selenium content in soil and crops for the utilization of selenium-enriched land resources and the development of selenium-enriched agricultural products. OBJECTIVES To understand the reasons of inconsistency about selenium content between soil and crops in Qingxi area, Ganxian County. METHODS Samples of 1734 topsoil, 57 sets of rice and corresponding root soil were collected from Qingxi area. The content of selenium and its speciation geochemistry in these samples were determined by inductively coupled plasma-mass spectrometry and inductively coupled plasma-optical emission spectrometry. The selenium content and distribution characteristics in soil and rice were systematically analyzed, and the influencing factors of selenium bioavailability in root soil were discussed. RESULTS The topsoil in the area was dominated by selenium-enriched soil and selenium-sufficient soil. The selenium content in soil were closely related to soil parent rocks. The rules of soil selenium content in different parent-rock areas were as follows: Paleozoic metamorphic rocks>Mesozoic granite>Neoproterozoic metamorphic rocks>Mesozoic terrigenous clastic rocks>Cenozoic quaternary. The selenium content in root soil were lower than 0.4mg/kg, and selenium-enrichment rate of rice was 64.91%, indicating that it had a high capacity to enrich selenium in the soil (enrichment coefficient was 20.05%). When the selenium content in root soil was more than 0.25mg/kg, the rate of selenium-enrichment reached up to 70.83%, and would produce high-quality selenium-enriched rice stably. The form of selenium was the main factor to influence selenium bioavailability in soil. When the content of total selenium in soil was low, water-soluble, ion-exchangeable and carbonate-bound selenium accounted for a high proportion, which enhanced the bioavailability of selenium. The weak ability of selenium adsorption by low content organic matter was also an important factor for the high bioavailability of selenium. CONCLUSIONS Selenium content in soil, soil physical and chemical index and the influence of selenium form on bioavailability of selenium in soil should be comprehensively considered when exploiting selenium-enriched soil and selenium-sufficient soil in Qingxi area, Ganxian County. It is beneficial to scientifically guide the delimitation of natural selenium-enriched land and develop selenium-enriched rice.

It is still one of the significant solutions to treat saline wastewater with thermal desalination technology, especially falling film evaporators. To improve the performance of the falling film evaporator, a numerical study on the gas–liquid two-phase flow characteristics of saline wastewater in the vertical pipe was conducted using the VOF model. The results showed that the inlet velocity of the saline wastewater increased under the same operating conditions, resulting in the thickening of the liquid film and the increase of the average convective heat transfer coefficient. Increasing the inlet temperature of the working liquid reduced the temperature difference, which led to a decrease of the average convective heat transfer coefficient. In addition, as the inlet concentration of the working liquid increased, the film flow rate and the average convective heat transfer coefficient first decreased and then increased slightly. The experimental results verified the accuracy of the numerical simulation, and the average error was 9.27%. HIGHLIGHTS The study of fluid microflow combined with heat transfer was proposed.; The distribution of heat transfer coefficient based on numerical simulation.; The distribution of heat transfer coefficient is correctly verified by experiments.; The effects of the various operating parameters on the heat and mass transfer processes are studied.;

The study on influence of loading rate on mechanical behavior of Zhanjiang clay, which is a kind of sensitive clay with high yield strength, could be noteworthy. In order to study the loading rate effects on intact mechanical properties of Zhanjiang clay, the self-boring pressuremeter tests (SBPT) under five different loading rates have been carried out. The influence of stress rate on undrained shear strength, linear stiffness and non-linear degradation of shear modulus of the soil have been discussed. It is shown that the greater stress rate results in higher undrained shear strength, proposing strong linear correlation between two variables, and that behaves differently from the results of tests controlling strain rate given in literature. The linear secant shear modulus Gur increases with stress rate and the undrained shear strengths varies within a class with small width after normalized by corresponding Gur, which indicates little effect caused by loading rate on the strain corresponding to the peak strength. The significant degradation of tangential shear modulus Gt, at higher gradient and the steeper Gt-γ decay curve have been observed when at higher stress rate. The value of shear strain where Gt decreases to less than Gur is about 0.1% for all stress rate conditions. The loading rate significantly affects the amplitude and the gradient of the decay of Gt in the corresponding class. The smaller the stress rate leads to the lower strain level where the decay of Gt mainly occurs. It is recognized that the special microstructure could account for the loading rate effects of Zhanjiang clay and this comment is preliminarily proved by super-mini-penetration tests conducted on both undisturbed and remolded samples. It is recommended that special attention should be paid to both the loading rate effects on in-situ mechanical properties and the influence of “loading rate history” on creep behavior of soils.

【Background】 Sweet sorghum has emerged as a crop with multiple usage ranging from feeding animals to being used for biofuel to sugar production. The large diurnal temperature variation in arid areas in northwest China is suitable for sweet sorghum growth, and its marginal lands including saline-alkali lands and sandy lands have become a main sweet sorghum production base in China. However, there is a lack of understanding about its optimal fertilization and irrigation. 【Objective】 This paper is to fill this gap by experimentally studying how irrigation and fertilization combine to affect growth and yield of sweet sorghum in these regions. 【Method】 The experiment was conducted in a desert oasis on the edge of Hexi corridor. It compared three irrigation amounts: 6 000 m3/hm2 (W1), 7 200 m3/hm2 (W2) and 8 400 m3/hm2 (W3), and three nitrogen fertilizations (N-P2O5-K2O with mass fractions of N, P and K all being 15%): 450 kg/hm2 (F1), 600 kg/hm2 (F2) and 750 kg/hm2 (F3). Overall, there were nine treatments which were arranged randomly in the field. In each treatment, we measured the growth traits and ultimate yield of the sorghum. 【Result】 ①The irrigation amount did not show significant effects on plant height, stem thickness and biological yield, but the fertilization did, with irrigation and fertilization combining to affect plant height and biological yield at significant level. ②W1F3 was optimal in terms of increasing plant height (to 333.1cm), stem thickness (to 22, 63 cm), biological yield (to 29.35 t/hm2) and water productivity (to 3.80 kg/m3), where were 12.16%, 11.29%, 30.82% and 87.19% up, respectively, compared to those in W3F3; its associated yield income, net income and production-to-investment ratio was 26 418.84 Yuan/hm2, 15 850.73 Yuan/hm2 and 2.50% respectively, increasing by 30.84%, 88.17% and 45.35%, compared with that in W3F3. ③Plant height, stem thickness, the number of internodes and leaves, leaf dry mass, stem dry quality, ear dry quality and stalk juice sugar hammer were all positively correlated with biological yield. In addition to juice yield, other traits including the stem thickness, plant height, leaf number and stem quality, were also found to positively affect biological yield. 【Conclusion】 Irrigation of 6 000 m3/hm2 coupled with 750 kg/hm2 of nitrogen fertilization is optimal for growth and ultimate yield of the sweet sorghum in northwestern China.

Energy harvesting is the process of converting external environmental energy into electrical energy. This technology has certain development potential in realizing self-powered low-power wireless sensors. At present, there are few researches on the adaptability of energy harvesting systems in terms of the application of energy harvesting technology in shears. Therefore, it is unable to achieve reliable applications. In order to solve the above problems, based on the characteristics of the working environment of shearer, this paper analyzes the feasibility of the weak environmental energy being harvested by shearer and the feasibility of converting the energy into electrical energy. It is pointed out that light energy, temperature difference heat energy and vibration energy are the three typical environmental energies that exist in shearer. Theses three energies have different adaptability due to different energy characteristics. Light energy has poor adaptability and is not suitable as an environmental energy source in energy harvesting technology. Temperature difference energy source is stable and the thermoelectric power generation device is easy to install. This energy has certain adaptability. However, the thermoelectric power generation device needs to be installed in the main heat producing part of shearer, and the installation location has certain restrictions. The total amount of vibration energy is large, and the piezoelectric power generation device has a simple structure. Vibration energy is less affected by the working environment factors and has a strong adaptability without installation location restrictions.

The inability to conduct hydrological simulations in areas that lack historical meteorological data is an important factor limiting the development of watershed models, understanding of watershed water resources, and ultimate development of effective sustainability policies. This study focuses on the Manas River Basin (MRB), which is a high-altitude area with no meteorological stations and is located on the northern slope of the Tianshan Mountains, northern China. The hydrological processes were simulated using the China Meteorological Assimilation Driving Datasets for the SWAT model (CMADS) using the Soil and Water Assessment Tool (SWAT) model. Simulated runoff was corrected using calibration/uncertainty and sensitivity program for the SWAT. Through parameter sensitivity analysis, parameter calibration, and verification, the Nash–Sutcliffe efficiency (NSE), adjusted R-square (Radj2{R}_{\text{adj}}^{2}), and percentage bias (PBIAS\text{PBIAS}) were selected for evaluation. The results were compared with statistics obtained from Kenswat Hydrological Station, where the monthly runoff simulation efficiency was NSE=0.64\text{NSE}\hspace{.25em}=0.64, Radj2=0.69{R}_{\text{adj}}^{2}\hspace{.25em}=0.69, and PBIAS=–0.9\text{PBIAS}\hspace{.25em}=\mbox{--}0.9, and the daily runoff simulation efficiency was NSE=0.75\text{NSE}\hspace{.25em}=0.75, Radj2{R}_{\text{adj}}^{2} = 0.75, PBIAS\text{PBIAS} = −1.5. These results indicate that by employing CMADS data, hydrological processes within the MRB can be adequately simulated. This finding is significant, as CMADS provide continuous temporal, detailed, and high-spatial-resolution meteorological data that can be used to build a hydrological model with adequate accuracy in areas that lack historical meteorological data.

Marsupialization is effective in the treatment of cystic lesions of the jaw. It is a simple operation that can result in minimal trauma, the reduction of postoperative recurrence, and maximum preservation of the surrounding tissue structure and function. However, there is a certain failure rate in clinical treatment due to the improper grasp of indications and nonstandard operation. The highest failure rate reported in the literature is 32.6%. To further standardize the clinical application of marsupialization and improve the success rate of treatment, we put forward an expert consensus of marsupialization in the treatment of jaw cystic lesions by reviewing the domestic and foreign literature and summarizing the experience in marsupialization from some famous domestic experts. In this consensus, we propose three elements of marsupialization: the establishment of the opening, the maintenance of cyst plugs and regular washing. The scope of application of marsupialization includes jaw cysts and cystic ameloblastomas. It is necessary to standardize the position of the opening, the size of the opening and the manufacture of the cyst plug, and a panoramic film or cone beam computed tomography(CBCT) should be used to observe the changes in the cystic cavity before and after operation. A second-stage operation should be performed when the lesion is significantly reduced by more than 50% or at least 5 mm from important structures; furthermore, the teeth of focus should be treated according to the relationship between the lesion and tooth and the type of tooth.

As study on the burst pressure probability distribution of single-layer cylindrical vessels is a basic work,the establishment of pressure vessels reliability design method was carried out to build precision evaluation system of pressure vessel strength calculating formula. The burst pressure probability distribution of single-layer cylindrical vessel was analyzed by using the hypothesis test method in the mathematical statistics theory,based on 84 sets measured burst pressure data of single-layer cylindrical vessel. Research results indicated that:（ 1） Based on the engineering practice of Chinese standard,the application range of the formula can be divided into the 3 groups according to the design pressure which are no exceeding 35 MPa,between35 MPa and 100 MPa,and no more than 100 MPa,respectively;（ 2） According to the relationship between design pressure and burst pressure,the actual burst pressure of the formula application range sample was no more than 105. 5 MPa,between 91. 0 MPa and 329. 6 MPa,and no more than 329. 6 MPa,respectively;（ 3） When the significance was 0. 05,the ratio of the samples measured burst pressure and mid-diameter formula and Tresca formula calculated values is 6 random variables with the normal distribution.（ 4） When the 2-sides confidence was 98%,the distribution parameters value range of 6 random variables were obtained respectively.

BACKGROUND Accelerator mass spectrometry (AMS) is the most popular technique for radiocarbon analysis. However, yielding high precision and low background 14C data by AMS is hindered by sample preparation. Therefore, improving the stability of graphitization and reducing the carbon contamination in the background helps to produce high quality 14C data and break through the 14C dating upper limit (about 50000ya), further broadening the application range of 14C chronology and isotope tracer. OBJECTIVES To provide basic reference for beginners or more experienced scientists who are going to set up a radiocarbon sample preparation vacuum line and methods. METHODS The development of graphite preparation technology with respect to sample preparation vacuum line apparatus and the underlying principle of H2/Fe, Zn/Fe and Zn-TiH2/Fe methods were reviewed. The advantages and drawbacks of these methods were also discussed. Additionally, the optimization of experimental conditions from the perspective of reductant, catalyst and graphitization temperature, accompanied by the inner relationship with the graphite yield, isotope fractionation and beam performance were emphatically discussed. The sources of carbon contamination and suitable control technology were also argued. RESULTS The optimized graphitization conditions by H2/Fe method was H2/CO2=2-2.5 (V/V), -325 meshes ion powder derived from hydrogen reduction with Fe/C=2-5 (m/m), and graphitization temperature of 500-550℃, while by Zn/Fe method it was Zn/C=50-80 (m/m), -325 meshes ion powder derived from hydrogen reduction with Fe/C=2-5 (m/m), and graphitization temperature of 400-450℃ for Zn reaction tube and 500-550℃ for Fe reaction tube. The carbon contamination originated from each step in the sample preparation procedure, which could be either reduced by high-temperature bake or calibrated by mathematical model, but it required more detailed study to strengthen our knowledge and eliminate the effects on results. CONCLUSIONS Both of the sample preparation methods used and the optimum of graphitization conditions are critical for good performance of the graphite target and the final precision and accuracy of the measurement, especially for ultra-small size samples. However, these effects could be reduced or even eliminated by optimizing the experimental procedures and the graphitization conditions or subtracting by mathematical models.

The graphene oxide was prepared via one step under low-temperature with natural flake graphite as raw material. Factors affecting oxidation degree and layer spacing of graphene oxide were discussed in the process of low-temperature oxidation, such as the dosage of oxidant and oxidation time in system. The results indicate that high C-O bond and low defect structure (ID:IG=0.63) graphene oxide with the carbon and oxygen atom ratio of 1.98 can be prepared in the condition of the potassium permanganate with natural flake graphite mass ratio of 1:3, oxidation temperature of 0℃, oxidation time of 48h.This way avoids the increase of graphene oxide defects in the process of Hummers preparation due to the formation of CO2, which leads to the hexagon fracture and the absence of carbon atoms. After microwave reduction, the reduced graphene oxide with low defect is obtained, which the distance between defects(LD)is 12nm,the defect density(nD) is 2.21×1011cm-2 and the ratio of ID:IG is only 0.85 (ΓG=32.1cm-1).