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The structure and thermal denaturation of three types of starch, including corn starch, wheat starch, and pea starch, were studied using one-dimensional mid infrared (MIR) spectroscopy, temperature dependent one-dimensional MIR spectroscopy and two-dimensional MIR spectroscopy. The results showed that the infrared absorption modes of the three types of starch structures mainly include the C—O stretching vibration mode (vC—O starch), and all three types of starch contain crystalline and amorphous structures. The structures of the three types of starch are sensitive to temperature changes, with the amorphous structure being the first to change and the crystalline structure being relatively stable. Under thermal disturbance factors, there are strong intramolecular interactions between the amorphous structures of wheat. This study expands the research scope of third-order mid infrared spectroscopy (including one-dimensional mid infrared (MIR) spectroscopy, temperature dependent one-dimensional MIR spectroscopy, and two-dimensional MIR spectroscopy) in the structure and thermal denaturation of crystalline/amorphous regions of starch.

Objective To explore and establish a new competency training model for non-orthopedics residents, and to enhance their learning effectiveness and clinical competency during the orthopedics training.Methods A comparison was made between the residents who received traditional teaching methods in 2022 (control group) with those who received the competency training model using the objective-based teaching method in 2023 (observation group). After the training, both groups underwent comprehensive assessments, including basic operational skills and theoretical examinations. Additionally, a questionnaire was used to evaluate the teaching effectiveness and self-assessment of the residents.Results A total of 97 resident were included with 50 in the control group and 47 in the observation group. The observation group performed better than the control group in both the theoretical knowledge exam and practical skill assessments, including debridement and suturing, plaster fixation, and bone traction. Additionally, the observation group scored higher in evaluations of teaching content and methods, teaching effectiveness, overall impression, and total scores across all evaluation items. In terms of self-assessments, the observation group also performed better in learning interest, self-learning ability, clinical thinking ability, expression ability, and communication skills. The differences were statistically significant (P

[Objective] To study the molecular biological mechanism for a case of ABO blood group B subtype, and perform three-dimensional modeling of the mutant enzyme. [Methods] The ABO phenotype was identified by the tube method and microcolumn gel method; the ABO gene of the proband was detected by sequence-specific primer polymerase chain reaction (PCR-SSP), and the exon 6 and 7 of the ABO gene were sequenced and analyzed. Homologous modeling of Bw.03 glycosyltransferase (GT) was carried out by Modeller and analyzed by PyMOL2.5.0 software. [Results] The weakening B antigen was detected in the proband sample by forward typing, and anti-B antibody was detected by reverse typing. PCR-SSP detection showed B, O gene, and the sequencing results showed c.721 C>T mutation in exon 7 of the B gene, resulting in p. Arg 241 Trp. Compared with the wild type, the structure of Bw.03GT was partially changed, and the intermolecular force analysis showed that the original three hydrogen bonds at 241 position disappeared. [Conclusion] Blood group molecular biology examination is helpful for the accurate identification of ambiguous blood group. Homologous modeling more intuitively shows the key site for the weakening of Bw.03 GT activity. The intermolecular force analysis can explain the root cause of enzyme activity weakening.

The number of patients with reduced blood volume due to haemorrhage, fractures, severe infections, extensive burns and tumours is increasing, and traditional blood products are no longer able to meet the increasing clinical demand. Therefore, plasma substitutes have become particularly important in fluid resuscitation, especially artificial colloidal solutions, which have a sustained volume expansion time and a good volume expansion effect, and can significantly improve the circulatory status of patients. This article aims to review the classification of artificial colloidal plasma substitutes and their research progress in clinical practice, in order provide a more rigorous, professional and standardized reference for medicine.

Urban-rural integration is a necessary way to realize the strategy of rural revitalization in the new era, and exploring the characteristics of the spatial correlation network of China's urban-rural integration and its formation mechanism is important for developing a comprehensive understanding of the spatial transmission mechanism of interregional urban-rural integration and provides a new policy perspective for the synergistic enhancement of the urban-rural integration level in each province. Based on China's interprovincial panel data from 2001 to 2021, the entropy method was applied to measure China's interprovincial urban-rural integration level, and the modified gravity model and social network analysis were used to explore the structural characteristics of China's spatial correlation network of urban-rural integration and its influencing factors. The results revealed the following: 1) During the study period, the level of China's interprovincial urban-rural integration showed an increasing trend, but the process of improvement was slow. Spatially, it showed a decreasing gradient from east to west, but the gap between the interprovincial urban-rural integration level gradually narrowed, with obvious spatial non-equilibrium. 2) China's urban-rural integration spatial association network became increasingly dense, complex, and close, and the main linkage flows of urban-rural integration occurred between geographically neighboring provinces and cities, such as Shanghai-Jiangsu, Shanghai-Zhejiang, and Beijing-Tianjin. The network connection was heterogeneous, and the network showed the characteristic of growth. However, the spatial connection of urban-rural integration did not reach the best level, and there is still much room for improvement. 3) Geospatial proximity, differences in the level of economic development, and urbanization had a significant positive effect on the optimization and evolution of the spatial linkage network of urban-rural integration, while differences in agricultural modernization and differences in advanced industrial structure showed a stage-by-stage effect over time. Differences in the scale of financial services did not have a significant effect. Accordingly, this study proposes countermeasures to optimize the spatial correlation network of urban-rural integration in China. Theoretically, it helps to deepen knowledge of the spatial effect and regional transmission of urban-rural integration in the geographical perspective. In practice, optimizing interprovincial urban-rural interaction and promoting cross-regional urban-rural integration development in a scientific and rational way are highly significant.

ObjectiveTo investigate serum β2-MG, sCHE, and PSGL-1 expression in patients with esophageal cancer and their relationship to lung infection after mediastinoscopy. MethodsA total of 118 patients with esophageal cancer were selected and divided into infected and uninfected groups according to whether they developed lung infection after surgery. An automatic microbiological identification system was used to detect the pathogenic bacteria of lung infection. ELISA was used to detect the levels of β2-MG, sCHE, and PSGL-1. Multivariate logistic regression was used to analyze the influencing factors of postoperative lung infection in patients with esophageal cancer. ROC curves were plotted to analyze the assessment value of serum β2-MG, sCHE, and PSGL-1 on postoperative lung infection. ResultsFifty-two strains of bacteria were isolated from the sputum of 38 patients with postoperative lung infections, and these included 35 (67.31%) Gram-negative, 14 (26.92%) Gram-positive, and 3 (5.77%) fungal strains. The difference in long-term smoking history between the infected and uninfected groups was statistically significant (P

Protein feed resources in China are scarce, which hinders the developement of feed industry and animal husbandry. Yeast protein is rich in nutrients and has significant development potential. Yeast strains were isolated and identified under acidic conditions (pH 3.5), from fermented flour, bovine rumen chyme, corn steep liquor, and other raw materials. Through the determination of the growth performance, bacterial protein and flavor of the strains, a promising high-protein yeast strain was identified as a potential strain for yeast protein processing. Further, the research indicated that 20 acid-tolerant yeast strains, including Saccharomyces cerevisiae, Pichia fermentans, Kluyveromyces marxianus, Yarrowia lipolytica, Candida tropicalis, Starmerella bacillaris, Zygosaccharomyces rouxii and Hanseniaspora thailandica, were obtained from different raw materials. Two superior strains, Pichia pastoris B-1 (7.65 g/L biomass, 4.96 g/L protein yield at pH 3.5; 9.32 g/L biomass, 5.81 g/L protein yield at pH 7.0) and Lactobacillus cerevisiae D-1 (8.00 g/L biomass, 3.91 g/L protein yield at pH 3.5; 14.91 g/L biomass, 6.87 g/L protein yield at pH 7.0), were identified based on biomass and protein production under shaking flask culture conditions. Flavor analysis revealed that strain B-1 had a higher content of flavor nucleotides and glutamic acid than strain D-1, along with a greater concentration of ester compounds. Thus, strain B-1 was identified as the potential strain for further application.. Therefore, B-1 strain was determined as the target strain. Finally, the growth characteristics and stress tolerance of B-1 strain were examined. It exhibited robust growth under conditions of pH≥2.0, temperature≤40 ℃ and NaCl concentration ( w /v )≤70 g/L.

The study employed three methods—odium tripolyphosphate method, neutral protease method, and ultrasonic treatment to modify the Chlorella protein in this paper. The investigation focused on changes in particle size, zeta potential distribution, antioxidant activity, functional properties, thermal stability, and structural characteristics before and after modification. The analysis revealed that compared to unmodified Chlorella protein, all three modification methods significantly reduced particle size and zeta potential. Additionally, significant improvements were observed in solubility, emulsification, emulsion stability, microstructure, and thermal stability. Overall, all three modification methods effectively improved the Chlorella protein. However, the sodium tripolyphosphate method showed only slight improvement in hydrophobicity and fluorescence intensity, with no significant overall improvement observed. The neutral protease method exhibited the most significant improvements in antioxidant activity, water-holding capacity, oil-holding capacity, thermal stability, and secondary structure of the Chlorella protein. For instance, the ABTS free radical scavenging rate increased from 22.95% to 35.72%, and the thermal stability improved by 11.48 ℃ compared to the control. The ultrasonic method significantly increased the solubility of Chlorella protein from 23.56% to 69.66%, emulsification from 70.29 m2/g to 95.25 m2/g, and emulsion stability from 10.74 min to 39.47 min. Additionally, reductions in particle size and improvements in zeta potential were observed.

This study investigated the structural characteristics and antioxidant activity of Polygonatum kingianum Coll.et Hemsl polysaccharides (NPKP) processed via nine-steaming-nine-drying methods. Monosaccharide composition analysis revealed that NPKP consists of rhamnose (3.5%), arabinose (4.6%), galactose (78.2%), glucose (2.1%), xylose (1.0%), mannose (1.3%), and galacturonic acid (9.4%). Molecular weight analysis revealed two main components in NPKP, with molecular weights of 196,857 Da and 13,653 Da. Methylation analysis indicated that NPKP is primarily linked by →4)-Glap-(1→ glycosidic bonds, accounting for 31.8% of the total, with a branching degree of 51.7%. Additionally, iodine-potassium iodide tests confirmed that NPKP is a highly branched polysaccharide. In vitro cellular experiments showed that NPKP significantly reduced reactive oxygen species (ROS) levels in HepG2 cells. It also upregulated antioxidant enzymes, including superoxide dismutase (SOD), catalase (CAT), and glutathione (GSH), alleviating oxidative stress induced by free fatty acids. Through these mechanisms, NPKP exhibited remarkable antioxidant capacity. This study provides a basis data for the application of Polygonatum polysaccharides as natural antioxidants and supports their role in mitigating oxidative stress-related diseases.

Chlorogenic acids (caffeoylquinic acids, CQAs), as key bioactive components in numerous traditional herbal medicines, are highly acclaimed for their various biological activities and therapeutic benefits. Nonetheless, their stability and therapeutic utility are challenged by the propensity to degrade under various environmental stimuli, including exposure to light, temperature fluctuations, and changes in pH levels. This inherent instability may lead to substantial losses, compromising the potency and consistency of herbal formulations and their derivative products. Therefore, high-performance liquid chromatography (HPLC) was employed to assess the content variation of seven chlorogenic acid derivatives, namely 3-caffeoylquinic acid (3-CQA), 4-caffeoylquinic acid (4-CQA), 5-caffeoylquinic acid (5-CQA), caffeic acid, 3,4-di-caffeoylquinic acid (3,4-diCQA), 3,5-di-caffeoylquinic acid (3,5-diCQA) and 4,5-di-caffeoylquinic acid (4,5-diCQA) in the stevia chlorogenic acid samples subjected to environmental stimuli. Furthermore, ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-QTOF MS/MS) was utilized to identify the degradation products of stevia chlorogenic acids under various induced conditions. Based on these degradation products, potential degradation pathways of stevia chlorogenic acids were inferred. The results indicated that stevia chlorogenic acids undergo degradation under induced conditions such as solvent exposure, light irradiation, high temperature, and varying pH levels, leading to a general decrease in total content of CQAs. The analysis of degradation products showed that both CQAs and diCQAs are prone to alkylate when stored in organic solvents such as alcohols and esters, resulting in alkylated chlorogenic acids. Under light exposure, they tend to degrade into caffeic acids. In high temperature environment, both dehydration and alkylation occur, producing dehydrated chlorogenic acids and further alkylated derivatives. In acidic or alkaline conditions, hydrolysis and structural transformations are common degradation pathways observed. In summary, dehydration, degradation, hydrolysis, and isomerization are four potential pathways of loss for stevia-derived chlorogenic acids subjected to environmental fluctuations. This study not only enhances the understanding of the stability mechanisms of chlorogenic acids, but also provides a scientific basis and practical guidance for formulating effective preservation strategy. This strategy is crucial for ensuring quality control of chlorogenic acid-containing products across various industries, including pharmaceuticals, health supplements, and cosmetics. By mitigating these degradation pathways, manufacturers can more effectively preserve the potency and efficacy of these compounds, thereby contributing to the overall quality and reliability of their products.

The Patented Naoxueshuan formula is an empirical formula for treating cerebral thrombosis, which has been proven to have significant and stable therapeutic effects through long-term clinical application. The Naoxueshuan formula has rich chemical components and diverse structures. In this study, chemical compositions of the Patent Naoxueshuan formula were analyzed by using ultra-performance liquid chromatography-time of flight mass spectrometry (UPLC-Q-TOF MS) and gas chromatography-mass spectrometry (GC-MS). For UPLC-Q-TOF MS analysis, the decoction of Naoxueshuan formula was separated using a Waters BEH C18 column (100 mm×2.1 mm, 1.7 μm). The mobile phase was comprised of 0.1% formic acid solution and acetonitrile with the flow rate of 0.3 mL/min. MS data was collected under positive and negative ion modes. For GC-MS analysis, the Agilent DB-5MS capillary column (30 m×0.25 mm, 0.25 μm) was employed to analyze the volatile components of the decoction of Naoxueshuan formula. The GC-MS analysis was performed under programmed heating conditions with electron ionization (EI) as the ion source and a scanning mass range of m/z 50-550. The main chromatographic peaks in both liquid and gas chromatograms were identified and analyzed according to the secondary mass spectrum information, NIST standard spectrum library and literatures. A total of 61 non-volatile components are identified in the Naoxueshuan decoction, including 14 flavonoids, 13 terpenoids, 9 glycosides, 5 organic acids, and 10 other types of compounds. A total of 29 volatile components are identified in the Naoxueshuan decoction, including 17 hydrocarbons, 3 alcohols, 1 aldehydes, 1 esters, 3 phenols, 2 terpenes and 2 other types of compounds. Among them, the organic acids are mainly from Salvia miltiorrhiza Bunge, the flavonoids are mainly from Pueraria lobata, Astragalus membranaceus (Fisch.) Bunge and Carthamus tinctorius L., the terpenoids are mainly from Salvia miltiorrhiza Bunge and Cornus officinalis Sieb. et Zucc. The volatile components are mainly from Ligusticum sinense, Fructus Amomi, Alpinia katsumadai Hayata, and Semen Alpiniae Katsumadai. This study provides an effective and comprehensive method for qualitative analysis of the chemical components in the Patented Naoxueshuan formula, and also provides data support for clarifying effective substances and establishing a quality evaluation system.

Carbon dioxide (CO2) geological storage is one of the most direct and effective measures to alleviate the greenhouse effect under the current technical conditions. Deep saline aquifers and cap beds are widely distributed in Lindian, Heilongjiang Province, offering favorable geological conditions and great potential for CO2 geological storage. However, due to the lack of oil exploration data, the high accuracy suitability evaluation has not been carried out. This study, in close alignment with the geological, economic, environmental, and other conditions, established a suitability evaluation system for CO2 geological storage. Following the principles of objectivity, comprehensiveness, focus, compatibility, and feasibility, the study decomposed 11 sub-layers of indicators and 32 evaluation indicators from the three index layers of storage safety suitability, storage potential suitability, and storage social and economic suitability, divided 5 evaluation levels. The evaluation system was applied to the deep saline aquifers of the Wuyuer Depression, Keshan−Yilong Anticline, Heiyupao Depression, and Qijia−Gulong Depression using data from geothermal exploration wells and the Analytic Hierarchy Process for a comprehensive fuzzy mathematical evaluation. The results show that the four secondary tectonic units in the study area exhibit good crustal stability. The cover layer is dominated by multiple sets of large thickness and continuous stability of argillite, while the reservoirs are all multiple sets of clastic rocks with large porosity and good permeability. These regions are not prone to geological hazards and are all suitable for CO2 geological storage, with the Heiyupao Depression being the most suitable. This study provides a scientific basis for the implementation of site selection and demonstration projects in this area.

Neurogenic Bowel Dysfunction (NBD) is one of the common complications of stroke and spinal cord injury. Traditional Chinese medicine (TCM) has a long history of diagnosis and treatment, and has been applied more and more in NBD in recent years and has made great achievements. In order to standardize the diagnosis and treatment of NBD in China, the TCM diagnosis and treatment standard is guaranteed. This guideline is based on the research results of TCM prevention and treatment of NBD at home and abroad, drawing on the principles and methods of evidence-based medical guideline development, establishing an evidence grading system through literature search and screening, literature evaluation and grading, and literature quality assessment, selecting experts for consultation and argumentation, and modifying the guideline based on the experts' opinions. This guideline standardizes the definition, diagnosis, TCM identification, treatment, efficacy evaluation and other specific contents of NBD, which is approved and released by Shandong Standardization Association (Standard No.T/SDAS866-2024), and is of great significance in guiding clinicians to use TCM in diagnosis and treatment of NBD and improving its prognosis, as well as in promoting its application.

Car-like robots often struggle with dynamics modeling owing to the use of nonstandardized parts and the complexity of accurately determining mechanical parameters, particularly tire characteristics like lateral deflection stiffness. Consequently, most current research and applications have relied on kinematic models for control, which frequently lead to inaccuracies and mismatches. These issues result in significant errors between actual and desired paths, causing erratic oscillations in the front wheel angle and angular velocity and adversely affecting the robot’s performance and smoothness. To address these issues, this paper introduces a novel approach: Feed-forward nonlinear model predictive control (FNMPC). This method is built on the principles of inverse kinematics and rolling optimization. Unlike other traditional methods, FNMPC incorporates feed-forward corner information into its predictive model, treating the front wheel angle as an additional dimension. This enhancement allows the model to better predict and correct deviations, thereby improving path-tracking accuracy. Extensive simulations conducted using Simulink and CarSim demonstrated the efficacy of the FNMPC approach. Results indicated that FNMPC significantly reduces the oscillations caused by model inaccuracies while maintaining high tracking accuracy. Specifically, FNMPC managed to keep displacement errors below 0.1106 m and heading errors within 0.1253 radians. When compared with other control strategies such as linear model predictive control, feed-forward linear model predictive control, pure tracking control, and Stanley control, FNMPC consistently demonstrated smaller and less dispersed errors, highlighting its superior performance in handling the complex dynamics of car-like robots. Moreover, FNMPC showed a remarkable improvement over traditional nonlinear model predictive control (NMPC), reducing the absolute cumulative control increment by 67.53% at its maximum values. Experimental validations using a wire-controlled car-like robot further validated FNMPC’s practical benefits. In these tests, the robot under FNMPC control maintained displacement errors within 0.1624 m and heading errors within 0.1138 radians, whereas traditional NMPC lost control of entering curves. In summary, FNMPC presents a substantial advancement in controlling car-like robots, offering enhanced accuracy and smoothness over existing methods. By effectively incorporating feed-forward corner information into the predictive model, FNMPC addresses the inherent challenges in car-like robot dynamics more efficiently. This approach not only improves control performance but also offers a more reliable and accurate method that could enhance the development of car-like robotic systems.

To examine the hypoglycemic effects and myocardial protection of Sanghuangporus vaninii polysaccharide (SP) in T2DM rats, these effects were assessed in rats fed a high glucose and high fat diet combined with streptozotocin (STZ). The rats were randomly assigned to one of the following six groups: the diabetes mellitus (DM), metformin (MET), low-, medium-, and high-dose SP (SPL, SPM, and SPH), and control (CN) groups. Following 4 weeks of continuous intervention by gavage, the weights and multiple physiological and biochemical indicators of rats were measured and recorded, and performed pathological observations of the pancreatic and myocardial tissues of rats. Results revealed that SP at all assessed doses could reduce weight loss in T2DM rats compared to the DM group, significantly reduce fasting blood glucose and serum insulin levels, and improve glucose tolerance (P

［Objective］ With the continuous improvement of metro network, the names of switches in the power supply system at all levels can no longer accurately mark the systems they belong to, meanwhile the duplicated and insufficient numbering also occur. Therefore, it is necessary to optimize the switch numbering in metro power supply system. ［Method］ The current situation of switch numbering scheme for the power supply system in Xi’an Metro, for example, is evaluated. Compared with the power supply systems for metros, electrified railways and the State Grid in other cities of China, the problems existing in the scheme are analyzed and specific solutions proposed. Starting from the characteristics of the power supply system switch numbers, considering their uniqueness and relevance, and combined with the planning of metro lines, the power supply system switch numbers are optimized and a new numbering method is proposed based on an analysis of its feasibility. ［Result & Conclusion］ The optimized switch numbering scheme for metro power supply system largely solves the numbering problems such as duplicate, disorder, poor organization and regularity. At the same time, it also realizes feeder and busbar classification, and voltage level identification, ensuring the uniqueness of the equipment names and numbers within each network area.

Background Given the increasing prevalence of the high incidence of bone and joint diseases in the elderly population, and significantly associated with higher mortality, more disability, decline in functional status and lower quality of life, this creates a large disease burden. There is currently no research on the prevalence and influencing factors of this disease in Henan Province. Objective To provide scientific basis for understanding the epidemic characteristics and influencing factors of bone and joint diseases in the elderly population in Henan Province and implementing precise prevention and control. Methods The multi-stage random cluster sampling method was used to obtain the demographic characteristics, past disease history, physical activity and physical indicators of permanent residents aged≥18 years old in Henan Province in 2018 through questionnaires, medical physical examination, laboratory testing and other methods. 1 055 people aged ≥60 years old were included in this study. Multivariate Logistic regression was used to analyze the characteristics and influencing factors of bone and joint diseases in the elderly population with different characteristics in Henan Province. Results The incidence rate of bone and joint diseases among the elderly population in Henan Province in 2018 was 28.13% (95%CI=28.10%-28.15%). Among them, women, urban areas, those with overweight or obesity, central obesity, dyslipidemia or hyperlipidemia, snoring history, moderate intensity activity, and non-smoking history have higher incidence rates, and the differences are statistically significant (P

ObjectiveThis study explores the use of the International Classification of Functioning, Disability and Health Rehabilitation Set (ICF-RS) to evaluate the physical, activities, and social participation levels of patients with chronic neck, shoulder, waist, and leg pain, and to explore its influencing factors.MethodsA total 162 patients with chronic neck, shoulder, hip and leg pain from the outpatient departments of the Central Hospital of Xiangyang City from July to December 2023, who had meet the diagnostic criteria and inclusion and exclusion criteria for chronic pain. A trained assessor used a questionnaire to collect detailed information on the patients' basic demographic data (sex, age, education level, medical expenses, body mass index), lifestyle habits (smoking, drinking), medical history (hypertension, hyperlipidemia, diabetes), and use of pain medication. The patients were assessed for their functional levels (physical function, activity function, social participation) using the ICF-RS. A multivariate ordered Logistic regression analysis was used to identify independent risk factors for the patients' body function, activity function, and social participation function (mild, moderate, and severe impairment).ResultsAmong the three dimensions of physical function, daily activities, and social participation of patients with chronic pain in outpatient clinics, about 1/3 of them with mild functional impairments being the main type. There were 10 ICF-RS categories (33.33%) with a functional impairment proportion > 50%, involving 4 categories in the physical function dimension, 2 categories in the daily activity function dimension, and 4 categories in the social participation dimension. The differences in exercise tolerance and mobility function among patients with chronic pain of different age groups were statistically significant (P=0.040, P=0.030); the differences in the ability to help others among patients with chronic pain of different age groups and whether they drank alcohol were statistically significant (P=0.008, P=0.021); the differences in entertainment and leisure ability among patients with chronic pain of different age groups and whether they had hyperlipidemia were statistically significant (P=0.028, P=0.004).ConclusionPatients with chronic pain have varying degrees of functional impairments in their body function, daily activities function, and social participation function, with mild functional impairments being the predominant; Age, alcohol consumption, and hyperlipidemia are independent influencing factors for functional impairment in body function, daily activity function, and social participation function.

本研究企圖整合教育擴張後高等教育水平分化的系所效應及生命歷程軌跡框架，補充過去系所選擇研究多聚焦於性別議題或討論中學階段的「選擇進入」議題之不足，且在方法論上檢視過去橫斷面思考薪資報酬的限制。本研究將薪資取得過程中的不確定性、不可預測性及個人生命各面向的多樣性納入薪資軌跡，以生命歷程軌跡框架理解STEM科系的選擇對個人薪資軌跡發展的影響。本研究合併2009～2020年的華人家庭動態資料庫，以成長曲線模型捕捉STEM科系對薪資成長的影響，分析結果發現：STEM專業訓練勞動者的薪資顯著高於非STEM專業的勞動者，且其優勢隨著工作經驗累積而增加；但此優勢存在性別差異，女性展現在起薪優勢，而男性則是後勢看漲的優勢；更精確地說，STEM專業的薪資發展優勢僅存在於一般大學男性之間。此結果揭示STEM專業訓練與勞動市場後果之間的關係如何受教育制度及生命歷程影響，這些勞動市場的STEM優勢及性別化差異，也將進一步影響STEM人才培育及其階層化後果。 This study attempts to integrate the literature in the horizontal differentiation of higher education expansion and the life course trajectory framework. It supplements the shortcomings of past studies on STEM education that mostly focused on gender issues or the issues of probability of “entering” STEM in high school, and examines the methodological limitations of using cross-sectional data. In this study, the labor market uncertainty and unpredictability, and the diversity in all aspects of personal life, are incorporated into the life course trajectory. This study systematically investigates the influence of majoring in STEM fields on individual earning trajectory. Merging the Panel Study of Family Dynamics from 2009 to 2020 and using the growth curve model to estimate the effects of STEM education on earning trajectory, the findings show that the earnings of workers trained in STEM majors are significantly higher than those of workers in non-STEM majors, and their advantages increase with the accumulation of work experience. However, there are gender differences in this advantage. Women have a starting salary advantage, while men have advantages of salary accumulation. Precisely, these advantages of STEM majors in the earnings only exist among male academic-track college graduates. These results reveal how the educational system and life course affect the relationship between STEM education and labor market outcomes. These patterns of STEM advantages and gender differences in the labor market will further influence the cultivation of STEM professionals and the patterns of social stratification.

Covalent organic frameworks(COFs) are a kind of porous materials with good crystalline and periodic structure formed by covalent bonding of monomers composed of C, H, O and other light elements. This kind of material shows great application potential in separation, energy storage, catalysis and other aspects because of its low density, high thermal stability and good chemical stability. In recent years, COFs materials have developed a variety of bonding bonds with different structures and characteristics from the initial boron-oxygen bonding bonds, and the most widely studied and in-depth class of COFs materials in these fields are composed of imine-like bonds. Imine-like bond is a class of imine bond derived from Schiff base reaction and its similar structure, which not only contains the advantages of imine bond, but also solves some potential application disadvantages. In recent years, the rapid development of nuclear energy has inevitably brought about the shortage of nuclear resources and environmental radioactive pollution, and how to extract and separate radionuclides has become a major problem to be solved urgently. Among the porous materials that have been developed and explored, COFs has its unique advantages compared with other inorganic porous materials, which can effectively avoid many application difficulties in the process of radionuclide extraction. As the most popular research object in the field of this material, imine-like COFs have been applied in the separation of actinides, especially in the adsorption separation of uranyl ions, which is of great significance to the nuclear fuel cycle and the prevention and control of nuclear environmental pollution. In this paper, the recent progress in the separation and detection of actinide elements by imine-like COFs is summarized, and the characteristics of imine-like bonds with different structures are described in detail. The adsorption mechanism and adsorption effect of COFs materials of each structure are summarized and compared in tables, showing how the design ideas affect the adsorption results, which is instructive for the selection of application scenarios to a certain extent. In addition, some new directions and thoughts on the material are proposed in this paper, which are reliable and forward-looking for improving the potential of imine-like COFs in practical applications. At the same time, the major challenges facing the material are summarized. COFs materials still show unfathomable development potential after decades of in-depth research, and fully demonstrate the urgent development space of this kind of materials in the separation of metal ions. Finally, the future development trend of this material is prospected.

Objective To develop an asymmetric porous guided bone regeneration (GBR) membrane made from antibacterial zinc oxide nanoparticle (nZnO)/poly (3-hydroxybutyrate-co-4-hydroxy butyrate) copolymer (P34HB), and detect its osteogenic performance. Methods Ultrasonic dispersion technique, solvent displacement method and freeze-drying technique were used to prepare P34HB composite GBR membrane loaded with nZnO at different doses (0%, 0.5%, 1.0% and 1.5%).Scanning electron microscopy (SEM) and energy spectrometry (EDS) were conducted to determine the load of nZnO and observe the structure of the prepared membrane.Then MC3T3-E1 cells were implanted in a 24-well culture plate with the prepared GBR membrane pre-laid in the well.Thus the experiment included blank control group (no membrane) and groups with membranes composing 0%, 0.5%, 1.0% and 1.5% nZnO, respectively.CCK-8 and cell scratch assays were used to detect cell proliferation capacity and migration ability.The protein adsorption capacity of GBR membrane was detected by protein adsorption experiment.The in vitro degradation of GBR membrane was tested; the activity of alkaline phosphatase (ALP) was detected with chemical test.And calcified nodules were observed with alizzarin red staining; the antibacterial ability of GBR membranes was tested with in vitro antibacterial experiments. Results Four groups of nZnO/P34HB composite GBR membranes with 0%, 0.5%, 1.0% and 1.5% nZnO were successfully prepared.SEM results showed that the composite membrane was porous on one side and dense on the other side.EDS indicated the incorporation of zinc elements in the composite membrane.The results of cell proliferation assay showed that 0.5% and 1.0% nZnO/P34HB group promoted the proliferation of MC3T3-E1 cells, when compared with the blank control group and 0% and 1.5% nZnO/P34HB groups (P < 0.05).The results of cell scratch assay showed that MC3T3-E1 cells in the 0.5% nZnO/P34HB group migrated significantly over the scratch edge, with the cell mobility higher than that of the other 3 membrane groups in 48 h after culture (P < 0.01).Protein adsorption experiment displayed there was no significant difference in optical density of the 4 group of membrane, indicating that the addition of nZnO had no effect on the protein adsorption capacity of the material itself.The results of enzymatic experiment showed that though the quality of the 4 membranes was continuously decreased with elapse of time, the degradation rate was still relatively lower after 28 d of treatment.ALP staining and alizarin red staining displayed that the 0.5% nZnO/P34HB group obtained the strongest ALP activity and the largest amount of calcified nodules when compared with the other 3 groups (P < 0.01).Higher mineralization was observed in the 0% and 0.5% nZnO/P 34 HB groups than the other 2 groups (P < 0.01).The results of in vitro antibacterial experiments showed that the number of colonies in the 0.5% nZnO/P 34 HB group was significantly less than that in the blank control group and the 0% nZnO/P34HB group (P < 0.01). Conclusion Our prepared P34HB composite GBR membrane loaded with nZnO is in asymmetric porous structure, and can promote cell proliferation, facilitate cell osteogenesis and have bacteriostatic ability.

ObjectivesThe wake of wind turbine affects the overall power output of wind farm. The analysis of wake characteristics is the key to study the influence of yaw control on wake. Therefore, the effects of different yaw angles of the upstream wind turbine on the wake characteristics (such as turbulence integral scale, power spectral density, etc. ) and the eddy current motion in the wake were studied, to understand the wake characteristics of the wind turbine under yaw conditions.MethodsThe wind tunnel was used to study the evolution law of the downstream wake of the wind turbine at 0°, 15° and 30° yaw angles. The turbulence integral scale and power spectral density were used to describe the wake characteristics, and the correlation between different feature points was analyzed.ResultsThe yaw angle has little effect on the horizontal wake, and the turbulence integral scale does not change much. The turbulent integral scale in the vertical direction has large fluctuations at different yaw angles. Through the analysis of the power spectral density, the contribution of eddy current motion to the turbulent kinetic energy of the wake is further quantified. The incoming current at 0° yaw is less disturbed by the rotation of the wind turbine than that at 15°. However, the increase of yaw angle does not always lead to an increase in the damage degree of wind turbines to the incoming current, and the decoupling effect on the incoming vortex structure at 30° is smaller than that at 15°.ConclusionsThere is a significant difference in the influence of yaw angle on the horizontal and vertical directions of wind turbine wake. The power spectral density analysis provides a quantitative basis for understanding the contribution of eddy current motion to the turbulent kinetic energy of the wake, which is helpful for in-depth study of the energy transfer and flow mechanism in the wake. There is not a simple positive correlation between the yaw angle and the disturbance and decoupling of the wind turbine on the incoming stream, which provides a reference for the optimal operation of the wind turbine and the layout of the wind farm.

ObjectivesAs a national energy base,the shift in energy policy in Xinjiang is of great significance to the realization of national energy strategy goals. The shift from controlling total amount and intensity of energy consumption to controlling total amount and intensity of carbon emissions in Xinjiang was investigated.MethodsTwo decoupling elasticity indexes of economic elasticity and energy consumption elasticity of carbon emissions were proposed, and the decoupling relationship between energy consumption and carbon emissions in Xinjiang was predicted.ResultsIt is found that Xinjiang has initially realized the relative decoupling of energy consumption and carbon emissions,and is expected to realize the absolute decoupling of energy consumption and carbon emissions in 2032. The shift in the dual-control index helps to improve the electrification level of end-use energy consumption in Xinjiang, but the pressure to maintain electricity supply increases.ConclusionsThe research results have guiding significance for energy policy making in Xinjiang and even the whole country, provide an empirical basis for realizing the goal of carbon neutrality, and also provide a reference for the transition path of other energy bases.

The radiation noise of mechanical noise has a significant impact on the acoustic detection performance of acoustic detection-based underwater gliders. In order to address this problem, this paper introduced sound absorption structure into the study of radiation noise of underwater gliders. Firstly, the theoretical models of different sound absorption structures were established, and according to the sound absorption theories of microperforated panel and porous materials, the composite sound absorption structure for reducing the radiation noise of underwater gliders was proposed, and the simulation analysis of the composite sound absorption structure was carried out by using Comsol software for guiding the design of the composite sound absorption structure. The simulation results show that the composite sound absorption structure of porous material layer-air cavity-microperforated panel-parallel air cavity has the best performance in the range of 0–2 000 Hz, and its average sound absorption coefficient is 0.663 in the range of 200–1 200 Hz, which can reduce the radiation noise of the underwater gliders under specific working conditions, weaken the interference of self-noise, and improve the detection ability of acoustic detection-based gliders.

Line-start permanent magnet synchronous motor (LSPMSM) has a great application potential in the field of water pump due to its self-starting ability, high efficiency, and high power factor. In order to improve the transient performance of the motor with pump load, a new type of asynchronous starting motor rotor topology with non-uniform distribution of rotor bar is proposed. By combining the non-uniform distribution of rotor bar with the built-in permanent magnet into a multi-layer magnetic flux barrier rotor structure, the rotor salient ratio is increased, and the pull-in synchronization ability of the motor is improved. Based on the finite element method, the no-load back EMF, starting ability, pull-in synchronization ability, steady-state electromagnetic torque, demagnetization, stress field, and temperature field distribution of the traditional structure motor and the new structure motor are comprehensively compared and analyzed. The results show that compared with the traditional rotor structure, the new rotor structure effectively improves the pull-in synchronization ability, the efficiency, and the power factor of the motor under rated operating conditions. Finally, a prototype is made and an experimental platform is built to verify the correctness of the simulation results and theoretical analysis.

The condylar movement trajectories in healthy people usually have relatively consistent characteristics, while the change of the trajectory of the temporomandibular condyle often indicates the occurrence of various oral diseases. An in-depth understanding of the condylar movement can help physicians diagnose and evaluate the efficacy of oral diseases. This article reviews the development of condylar motion tracing technique, and introduces the research progress and clinical application status of condylar motion tracing analysis in various oral diseases. At the same time, the limitations of the current condylar motion tracing technique and the prospect of future clinical application are proposed.

The tangent quadruple circular-arc harmonic gear has the advantages of strong load capacity and transmission stability. In order to meet requirements of high efficiency and precision machining of tangent quadruple circular-arc harmonic gears, a method of gear skiving and manufacture of the tangent quadruple circular-arc harmonic flexspline was presented based on establishing the two-parameters conjugated tooth surface of the gear tooth. The kinematic model of skiving and the mathematical model of the tangent quadruple circular-arc harmonic flexspline were established. Then the meshing equation of the two-parameters conjugated tooth surface between the generative cutter and the gear tooth surface was derived. The accurate cutting edges on the normal surface of the skiving tool were obtained by solving conjugated tooth surface and constructing normal equation of the tool. The skiving tool was designed and manufactured by using the cutting edges on the end surface. The simulation and cutting experiment have been carried out to verify the effectiveness of the proposed tool design method, which has a higher accuracy for machining the tangent quadruple circular-arc harmonic flexspline. The results could provide guidance for the high efficiency and high precision manufacturing of tangent quadruple circular-arc harmonic flexsplines.

Atomizing nozzle is the core component of the gas atomization process, which structural parameters, especially the melt tip taper angle of the delivery tube, have the great impact on the gas atomization results. Changing the taper angle of melt tip is more effective and economical than changing the atomization process parameters such as gas pressure and temperature. The computational fluid dynamics (CFD) method was used to simulate the internal flow field in the spray chamber with different melt tip taper angles in this paper. The commercial CFD software FLUENT was used to calculate and visualize the complex multiphase flow process in the closed spray chamber with high temperature and high pressure. The influence of various factors on the melt breaking effect in the single phase flow field was analyzed, and the volume of fluid (VOF) model was used to simulate the primary atomization process. The results show that the direction of air flow can be changed by changing the melt tip taper angle (16°, 22°, 28°, 34°, 40°, and 46°). With the change of taper angle, the stagnation point position, stagnation pressure, and suction pressure show the regular characteristics in single-phase flow field. The mass median diameter (MMD) of the primary atomization also varies with the change of melt tip taper angle. The droplet size distribution after primary atomization can be controlled by changing the melt tip taper angle. The minimum MMD is 304 μm when the melt tip taper angle is 34°.

In order to optimize the dust control flow field structure of the fully mechanized excavation face in coal mine, improve the dust control efficiency of the local ventilation system, achieve energy conservation and emission reduction in the mine, and low-carbon prevention and control of dust disasters, numerical simulation was used to study the respiratory dust pollution of the fully mechanized excavation face under different pressure air jet volume and action height conditions. The results showed that the pressure air jet volume is the main factor affecting the range of respiratory dust pollution. As the volume increases, the time for dust particle aggregation to escape to the working face decreases, the dust particle aggregation area continuously moves backward, and the range of respiratory dust pollution increases; the pressure air jet action height is the main factor affecting the degree of respiratory dust pollution in the area where the excavation driver is located. As the height increases, the overall range of dust pollution slightly increases, and the average dust mass concentration in the area where the excavation driver is located shows a trend of first increasing and then decreasing. Based on this, the optimal pressurized air jet volume was determined to be 200 m3/min and the optimal action height was 2 m. After on-site application, the respiratory dust concentration at the excavation driver’s site decreased by 55.4%, and the respiratory dust mass concentration in the rear area of the excavation machine decreased by more than 73%.

旨在为开发大豆蛋白的脱敏技术提供参考，对大豆分离蛋白（SPI）进行挤压膨化处理，对不同挤压膨化温度下SPI的抗原性、十二烷基硫酸钠-聚丙烯酰胺凝胶电泳（SDS-PAGE）、氨基酸组成、溶解度、紫外吸收光谱、内源荧光光谱及表面疏水性进行分析。结果表明：随着挤压膨化温度的升高，SPI抗原性呈现先降低再升高的趋势，145 ℃时SPI的抗原性下降最为显著；SPI中抗原蛋白β-伴大豆球蛋白的α、α′、β亚基以及大豆球蛋白的酸性亚基和碱性亚基均发生明显降解；SPI的氨基酸组成、必需氨基酸含量与氨基酸总量比值无明显变化，营养性保持良好；SPI溶解度降低；氢键、二硫键、疏水相互作用均是维持SPI空间结构的分子作用力，其中氢键起主要作用；SPI的紫外光谱和内源荧光光谱均出现不同程度的红移，紫外吸收强度及荧光强度发生变化，表面疏水性显著下降，SPI的三级结构发生改变。综上，挤压膨化能够在一定程度上降低SPI的抗原性，并影响其空间结构。 In order to provide reference for the development of desensitization technology of soybean protein, the antigenicity, SDS-PAGE, amino acid composition, solubility, UV absorption spectra, endogenous fluorescence spectra and surface hydrophobicity of the soybean protein isolate (SPI) extruded at different extrusion temperatures. The results showed that the antigenicity of SPI decreased first and then increased with the increase of extrusion temperature, and the antigenicity of SPI decreased most significantly at 145 ℃. The α, α′ and β subunits of the antigen protein β-conglycinin and the acidic and basic subunits of glycinin in SPI were significantly degraded. The amino acid composition and the ratio of essential amino acids to total amino acids of SPI had no obvious change, and the nutritional characteristics of SPI remained good. After extrusion, the solubility of SPI decreased, and hydrogen bond, disulfide bond and hydrophobic interaction were the molecular forces that maintained SPI spatial structure, in which hydrogen bond played the main role. The UV and endogenous fluorescence spectra of SPI extruded showed different degrees of redshift, the UV absorption intensity and fluorescence intensity changed, the surface hydrophobicity decreased significantly, and the tertiary structure of SPI changed. In conclusion, extrusion can reduce the antigenicity of SPI to a certain extent and affect its spatial structure.

The research aimed to investigate effects of the addition of Clitocybe squamulosa and Auricularia heimuer powders on processing properties of doughs and quality of dried noodles. For this purpose, wheat flour was mixed uniformly with C. squamulosa and A. heimuer powders at different ratios (100:0, 99:1, 97:3, 95:5, 90:10) respectively, the processing properties of mixed flour doughs were preliminarily determined by texture analyzer, viscometer and rheometer, and then the edible quality of prepared dried noodles were systematically analyzed. The results showed that compared with the pure wheat flour dough, the hardness of doughs increased significantly (P

With the increasing embrace of preprints by scientific and social science disciplines, the humanities have garnered comparatively less attention in their development. This study targeted 1,734 preprints uploaded on the SSRN Literature Research Network between 1997 and 2020. The findings reveal substantial preprint growth in both traditional and interdisciplinary literature categories since 2007. A total of 1,376 authors were identified as affiliated with 676 institutions across 75 countries and represented 25 disciplines. Only 6 authors shared preprints in both interdisciplinary and traditional literature, but they were productive, contributing 8-100 preprints. Law authors dominated interdisciplinary literature preprints because most preprints were related to law and literature. This differed in that language and literature authors predominantly shared preprints in traditional literature. Additionally, there is a slightly higher publication rate in interdisciplinary literature preprints than in traditional literature preprints (36.6% vs. 31.8%). Traditional literature preprints showed a significantly higher preference for publishing in the format of journal articles compared to interdisciplinary literature preprints (88.7% vs. 77.3%).

To address the problems of strong noise interference, long detection times, uneven fuselage surfaces, lack of visual information in two-dimensional images, and difficulty in automatic detection, an automatic detection algorithm for aircraft skin pit damage based on a multiscale surface model was designed. First, an automatic acquisition platform system was constructed using an unmanned vehicle, a lifting pole, and a depth camera. The point-cloud data of the aircraft skin was obtained using this acquisition platform system. The point-cloud data were then preprocessed using the radius filter algorithm, voxel grid filter algorithm, and moving least squares algorithm. Then, the preprocessed point-cloud data were divided into multiscale regions and split into multiple local skin mesh regions to obtain multiple local grid area data. For each local grid region data, the surface models of each local grid region and regional spatial adjacency were obtained by constructing and optimizing the estimation of the local quadric surface based on the random sampling consensus algorithm. The spatial adjacency, surface model, and its index together form the region tree. The local surface models at different scales were aggregated by storing information and normal vector angles in the region tree to identify the damaged and nondamaged regions. Finally, surface features, such as curvature and normal vector, were used to cluster the pit points in the damaged area, and the pit point-cloud data were aggregated to obtain the final pit damage results. The proposed algorithm was compared with existing traditional algorithms, such as the point-cloud block method and the point feature region growth method based on normal vector and curvature. Experimental results showed that the accuracy, recall, and F-value of the point-cloud block method were 4.00%, 20.00%, and 6.67%, respectively, with an average detection time of 20 s. For the point feature region growth method based on normal vector and curvature, the accuracy, recall, and F-value were 30.77%, 26.67%, and 28.79%, respectively, with an average detection time of 25 s. The accuracy, recall, F-value, and average detection time were significantly improved, with mean values of 92.86%, 86.67%, 89.92%, and 6 s, respectively. Additionally, the detection results of the three algorithms on the aircraft skin engine, fuselage, and wing were compared, and the influence of curvature in different regions on the algorithm was analyzed. The detection results of the proposed algorithm were significantly better than those of existing traditional algorithms, such as the point-cloud block method and the point feature area growth method based on normal vector and curvature. The proposed algorithm achieved the goal of automatically detecting pit damage in aircraft skin scenes.

Cell transfection is a specialized technique for introducing exogenous molecules, such as RNA and DNA, into cells and has become a prevalent method in gene functionality studies. The most frequently employed cell transfection methods include electroporation, viral infection, and liposome transfection. Liposome transfection is a prevalent technique in molecular biology for studying gene function and regulation. Liposome transfection has the advantages of wide applicability, superior efficiency, and simple operation. However, most liposome transfection reagents on the market are designed based on mammalian cells. Cell membrane composition, temperature adaptation range, and oxygen demand in teleost cells differ substantially from those in mammalian cells. Accordingly, the efficiency of liposome transfection in teleost cells is limited, and obtaining stable transfected cells directly through screening is challenging. Therefore, after the transfection of conventional transient expression vectors into teleost cells via liposomes, most of the plasmid copies tend to vanish due to cell proliferation after the duration of screening. Furthermore, the insignificant number of cells retaining plasmids makes it difficult to correctly integrate plasmids into the genome sequence, which hinders screening for stable cell lines. In this study, we investigated a method of rapidly obtaining stable transfected cells of Japanese flounder by transfecting the Tol2 transposon recombinant vector with liposomes. The CMV-EGFP-pminiTol2 vector was modified from the pminiTol2 plasmid, sustaining the functionality of the Tol2 transposable element to facilitate the highly efficient insertion of target genes into genomic DNA. The CMV-EGFP-pminiTol2 plasmid was highly suitable for stable transformation screening in Japanese flounder cells. This advantageous trait was mainly attributed to the following four aspects: (1) The CMV-EGFP-pminiTol2 plasmid carries autonomous transposon elements that can significantly enhance the integration ability of target genes. (2) The CMV-EGFP-pminiTol2 plasmid carries EGFP, allowing researchers to visualize transfection and screening effects directly via fluorescence microscopy. (3) The CMV-EGFP-pminiTol2 plasmid incorporates a neomycin resistance selection marker, which can be used to quickly and successfully screen transfected cells after G418 screening. (4) The multiple cloning site (MCS) region of the CMV-EGFP-pminiTol2 plasmid is mutated to retain two unique cleavage sites (XhoI and XmaI); plasmids can be linearized through these two sites, allowing the target gene to be inserted using homologous recombinase cloning. CMV-EGFP-pminiTol2 and pCS-TP plasmids were co-transfected into flounder cells via liposome encapsulation, and stable transfected cells were obtained through neomycin (800 μg/mL) screening for 2–3 weeks. After 2 weeks of screening, cells were stably cultured for 2–3 weeks without G418 screening. Finally, the EGFP fluorescence of the cells was observed using an inverted fluorescence microscope to confirm the transfection efficiency of the cells. The results revealed that the CMV-EGFP-pminiTol2 plasmid-transfected experimental group successfully expressed EGFP in all cells after G418 selection. In the pEGFP-C1- or pEGFP-N1-transfected control group, only a minor fraction of cells (≤10%) sustained EGFP expression after G418 screening. The CMV-EGFP- pminiTol2 vector is therefore suitable for the preparation of stable transgenic cells in Japanese flounder, offering numerous advantages, including reduced screening time, stable exogenous gene expression, simplified operations, and relatively low cost. Consequently, researchers can insert their desired target genes into the CMV-EGFP-pminiTol2 vector to construct stable transformed cells for investigations such as functional analysis and assessments of subcellular localization and long-term regulation. This study describes a novel approach to rapidly screening stably transformed flounder cells using the Tol2 transposon system. The results can be applied to molecular biology research in flounder and provide novel insights for constructing and screening stable transformations in teleost cells.

ObjectiveTo evaluate the effectiveness of a lung cancer screening program for early diagnosis and treatment of the disease among community residents in Nanshan district, Shenzhen city, Guangdong province, and to provide evidence for optimizing regional lung cancer prevention and control policies. MethodsA total of 11 000 residents aged 40 – 74 years were recruited from 59 communities in Nanshan district, Shenzhen city, Guangdong province, through publicity and mobilization from December 2020 to January 2022. A face-to-face questionnaire interview was conducted to collect relevant information to assess the lung cancer risk of the participants based on the China National Cancer Center Lung Cancer Model (NCC-LCm2021 Model). Participants identified as being at high risk for lung cancer underwent low-dose spiral computed tomography (LDCT) of the lungs. Participants at high risk for lung cancer who did not undergo LDCT were followed up. Participants with LDCT results of suspected lung cancer/positive lung nodules/semi-positive lung nodules were followed for 2 years. The effectiveness of lung cancer screening among participants was evaluated by analyzing the detection rate of participants at high risk for lung cancer, the screening rate of LDCT, the follow-up results of patients with lung nodules, and the cost-effectiveness of the program. ResultsOf the 8 266 (75.1% of all participants) who completed the risk assessment, 3 051 (36.9%) were identified as being at high risk for lung cancer based on the NCC-LCm2021 model, and the detection rates increased with increasing age for male, female, and total participants (χ2trend = 1 822.37, 2 209.14, and 4 020.10, all Ptrend < 0.001). Of the 3 051 participants at high risk for lung cancer, 1 952 (64.0%) underwent LDCT screening, with the highest screening rate (73.9%) among female participants aged 56 – 60 years. The LDCT screening detected 19 cases of suspected lung cancer (1.0%), 328 cases of positive lung nodules (16.9%), and 604 cases of semi-positive lung nodules (30.9%). The highest detection rate of suspected lung cancer was found in participants aged 71 – 74 years (1.6%); the highest detection rate of positive lung nodules was found in participants aged 66 – 70 years (19.4%); and the highest detection rate of semi-positive lung nodules was found in participants aged 51 – 55 years (36.9%). By the end of the 2-year health education follow-up, a total of 16 lung cancer cases were diagnosed among participants with suspected lung cancer/positive lung nodules/semi-positive lung nodules. The overall lung cancer detection rate was 193.6/100 000, and the lung cancer early detection rate was 87.5% for the screening program. For the screening program, the total cost was 1.304 million Chinese yuan (CNY); the per capita cost was 157.8 CNY; the cost-effectiveness ratio (CER) for each confirmed lung cancer case was 82 000 CNY; the average cost for each early-diagnosed lung cancer case was 93 000 CNY; and the early detection cost index (EDCI) was 0.22. The above indicators suggest a high cost-effectiveness of the program. ConclusionsThe lung cancer screening program for early diagnosis and treatment of the disease among community residents in Nanshan district, Shenzhen city, has achieved good results and the results suggest that more residents aged ≥ 50 years should be encouraged to participate the program to improve the effectiveness of the lung cancer early diagnosis and treatment program.

[Objective]Grape picking is a key link in increasing production. However, in this process, a large amount of manpower and material resources are required, which makes the picking process complex and slow. To enhance harvesting efficiency and achieve automated grape harvesting, an improved YOLOv8n object detection model named 3C-YOLOv8n was proposed, which integrates the RealSense D415 depth camera for grape recognition and localization.[Methods]The propoesed 3C-YOLOv8n incorporated a convolutional block attention module (CBAM) between the first C2f module and the third Conv module in the backbone network. Additionally, a channel attention (CA) module was added at the end of the backbone structure, resulting in a new 2C-C2f backbone network architecture. This design enabled the model to sequentially infer attention maps across two independent dimensions (channel and spatial), optimize features by considering relationships between channels and positional information. The network structure was both flexible and lightweight. Furthermore, the Content-aware ReAssembly of Features up sampling operator was implemented to support instance-specific kernels (such as deconvolution) for feature reconstruction with neighboring pixels, replacing the nearest neighbor interpolation operator in the YOLOv8n neck network. This enhancement increased the receptive field and guided the reconstruction process based on input features while maintaining low parameter and computational complexity, thereby forming the 3C-YOLOv8n model. The pyrealsense2 library was utilized to obtain pixel position information from the target area using the Intel RealSense D415 camera. During this process, the depth camera was used to capture images, and target detection algorithms were employed to pinpoint the location of grapes. The camera's depth sensor facilitated the acquisition of the three-dimensional point cloud of grapes, allowing for the calculation of the distance from the pixel point to the camera and the subsequent determination of the three-dimensional coordinates of the center of the target's bounding box in the camera coordinate system, thus achieving grape recognition and localization.[Results and Discussions]Comparative and ablation experiments were conducted. it was observed that the 3C-YOLOv8n model achieved a mean average precision (mAP) of 94.3% at an intersection ratio of 0.5 (IOU=0.5), surpassing the YOLOv8n model by 1%. The accuracy (P) and recall (R) rates were recorded at 91.6% and 86.4%, respectively, reflecting increases of 0.1% and 0.7%. The F1-Score also improved by 0.4%, demonstrating that the improved network model met the experimental accuracy and recall requirements. In terms of loss, the 3C-YOLOv8n algorithm exhibited superior performance, with a rapid decrease in loss values and minimal fluctuations, ultimately leading to a minimized loss value. This indicated that the improved algorithm quickly reached a convergence state, enhancing both model accuracy and convergence speed. The ablation experiments revealed that the original YOLOv8n model yielded a mAP of 93.3%. The integration of the CBAM and CA attention mechanisms into the YOLOv8n backbone resulted in mAP values of 93.5% each. The addition of the Content-aware ReAssembly of Features up sampling operator to the neck network of YOLOv8n produced a 0.5% increase in mAP, culminating in a value of 93.8%. The combination of the three improvement strategies yielded mAP increases of 0.3, 0.7, and 0.8%, respectively, compared to the YOLOv8n model. Overall, the 3C-YOLOv8n model demonstrated the best detection performance, achieving the highest mAP of 94.3%. The ablation results confirmed the positive impact of the proposed improvement strategies on the experimental outcomes. Compared to other mainstream YOLO series algorithms, all evaluation metrics showed enhancements, with the lowest missed detection and false detection rates among all tested algorithms, underscoring its practical advantages in detection tasks.[Conclusions]By effectively addressing the inefficiencies of manual labor, 3C-YOLOv8n network model not only enhances the precision of grape recognition and localization but also significantly optimizes overall harvesting efficiency. Its superior performance in evaluation metrics such as precision, recall, mAP, and F1-Score, alongside the lowest recorded loss values among YOLO series algorithms, indicates a remarkable advancement in model convergence and operational effectiveness. Furthermore, the model's high accuracy in grape target recognition not only lays the groundwork for automated harvesting systems but also enables the implementation of complementary intelligent operations.

The interaction and feedback between soil and vegetation will promote the restoration of damaged mine ecosystems towards a virtuous cycle, especially in surface mine dump site reclamation areas. However, the lack of understanding of the correlation and mutual feedback mechanism between vegetation restoration and soil functions limits the scientific formulation of vegetation reconstruction strategies for surface mine dump sites. This study aims to reveal the trade-off and synergistic relationship between vegetation succession and soil system functions during the vegetation restoration process. Using methods such as field surveys, high-throughput sequencing, and resilience assessment models, four reclamation areas with different reclamation timings were selected in the Heidaigou surface coal mine on the Loess Plateau, and a resilience assessment model and trade-off synergy were constructed for five plant restoration types: grassland, shrub, coniferous forest, broad-leaved forest and mixed forest. The results show that: ① compared with bare land, the recovery degree of soil indicators is 30%−80% and the vegetation index recovery degree is 20%−75% after 8−30 a of restoration. ② The recovery rate of soil nutrient conservation and ecological carbon sink functions of grassland and shrubs peaked at 15 a, and the recovery rate of coniferous forest, broadleaf forest and mixed forest peaked at 25 a. The recovery degree of the soil system is mixed forest > grassland > coniferous forest > broadleaf forest > shrubs, and the vegetation system recovery is mixed forest > broadleaf forest > coniferous forest > grassland > shrubs. ③ In terms of the overall trend, the functional resilience of grassland, shrub and broad-leaved forest vegetation and soil systems is mainly in a trade-off relationship, while coniferous forest and mixed forest are mainly in a synergistic relationship. It concludes that the vegetation restoration significantly improves the physical, chemical, biological properties and vegetation community characteristics of the reclaimed soil, the reclamation years significantly affects the recovery elasticity and rate of the soil-vegetation system in the surface mine area of the Loess Plateau, China. As the reclamation years increase, there is a trade-off relationship between soil-vegetation system indicators. The research results confirm that different vegetation types have temporal characteristics in improving the resilience of the soil-vegetation system. Therefore, it is recommended to appropriately adjust the vegetation clustering strategy, allocate vegetation types in a timely manner, and fully coordinate the relationship between various soil functions to optimize the surface mine ecology of the Loess Plateau. The study provides a scientific basis for the restoration planning and management of disturbed surface mine.

Objective To investigate the influencing factors of postoperative urinary tract infection in benign prostatic hyperplasia （BPH） patients complicated with non-alcoholic fatty liver disease （NAFLD）. Methods Clinical data of 159 BPH patients complicated with NAFLD admitted to Xiaogan Hospital affiliated to Wuhan University of Science and Technology from January 2020 to March 2024 were retrospectively analyzed. All patients were divided into the infection （n = 48） and non-infection groups （n =111） according to the occurrence of urinary tract infection. Logistic regression analysis was used to analyze the influencing factors of urinary tract infection. Results Operation time>1 h [OR（95%CI）=3.492 （1.257，9.697）]， history of diabetes mellitus [OR（95%CI）=3.073 （1.075， 8.783）]， time of indwelling catheter after operation>7 days [OR（95%CI）=3.121 （1.093，8.911）]， prostate weight>50 g [OR（95%CI）=3.209 （1.203，8.562）]， abnormal liver function [OR（95%CI）=2.616 （1.126，7.569）]， systemic inflammatory index [SII， OR（95%CI）=1.005 （1.002，1.007）] and serum amyloid A[SAA， OR（95%CI）=1.014 （1.001，1.028）] were the independent influencing factors for postoperative urinary tract infection in BPH complicated with NAFLD （all P < 0.05）. Prognostic nutritional index [PNI， OR（95%CI）=0.968 （0.949，0.987）] was an independent protective factor for postoperative urinary tract infection （P < 0.05）. There were no significant differences in the history of hypertension， age， body mass index （BMI）， maximum urinary flow rate （Qmax）， length of hospital stay and triglyceride （all P > 0.05）. According to the results of multivariate Logistic regression analysis， a prediction model for postoperative urinary tract infection in BPH complicated with NAFLD was established. The area under the receiver operating characteristic （ROC） curve （AUC） was 0.898 （95%CI： 0.849-0.947， P < 0.001）， the specificity was calculated as 0.793， the sensitivity was 0.854， the positive predictive value was 0.641 and the negative predictive value was 0.926， respectively. Conclusions Operation time， history of diabetes mellitus， postoperative indwelling catheter time， prostate weight， abnormal liver function， SII， SAA and PNI are the influencing factors of postoperative urinary tract infection in BPH complicated with NAFLD. This prediction model based on these influencing factors has certain predictive value.

The nuclear interaction serves as a fundamental component in the investigation of the mechanisms underlying nuclear reactions. The optical model potential (OMP) is extensively employed to phenomenologically describe the interaction of nuclear collisions. It is well established that the OMPs are closely linked to the internal structures of the nuclei involved in the collision. Consequently, it follows that OMPs for weakly-bound systems will differ significantly from those of tightly-bound systems, a fact that has generated considerable interest in current research. For tightly bound nuclear systems, OMPs exhibit a threshold anomaly （TA） phenomenon in the energy region near the Coulomb barrier, where the connection between the real and imaginary potentials is well described by the dispersion relation. For weakly bound nuclei (such as 6Li and 9Be) induced reactions, OMPs show an abnormal “threshold anomaly” phenomenon, where the connection between the real and imaginary potentials is well described by the dispersion relation. However, the behavior of OMPs remains controversial for the weakly bound nucleus 7Li induced reactions. Therefore, this study is focused on the 7Li+207Pb system, aiming to measure and analyze its phenomenological OMP with precision. The experiment was carried out on the R60 nuclear reaction terminal of the HI-13 tandem accelerator located at the China Institute of Atomic Energy. In the present work, elastic scattering angular distributions of the 7Li+207Pb system have been measured with high precision at energies near and well below the Coulomb barrier. Through fitting the angle distributions of elastic scattering by the optical model, the OMP parameters of the 7Li system were successfully determined. Although 7Li was commonly considered as a weakly bound nucleus with a low breakup threshold, its OMP exhibits the typical threshold anomaly phenomenon: The real potential presents a bell-like shape around the barrier, and the imaginary potential decreases below the barrier and then falls quickly down to 0. In addition, experimental results show the dispersion relation is not applicable for this system, which may be a common phenomenon for exotic nuclear systems. Moreover, the reaction threshold of the 7Li+207Pb system is determined from the data in the deep sub-barrier energy region, about 0.82VB (the height of the Coulomb barrier), which is between the 0.93VB of the typical tightly bound 16O+208Pb system and the 0.73VB of the weakly bound 6Li+232Th system, it implies that a relationship may exist in between the reaction threshold and break threshold. Therefore, the systematic relationship between the reaction threshold and the breakup threshold demands further investigation. This highlights the influence of breakup on the reaction cross section and can yield valuable insights for reactions involving weakly bound nuclei.

Dike is an important facility to prevent flood disasters in the area of lakes and plain rivers. There are lots of serious loss consequences when dike engineering is in danger and causes destruction. Therefore, risk assessment, as well as management and control of dike engineering danger have been given great importance all over the world. However, the uncertain factors such as dike material properties, earthquakes, and extremely heavy rainfall in dike engineering systems are not quantitatively characterized insufficiently, and the understanding of occurrence environments where dike engineering danger exists is not clear. As a result, the mechanism and evolution process of dike engineering danger are not clarified. Besides, the risk assessment methods of dike engineering danger are still mainly semi-qualitative and semi-quantitative, lacking corresponding comprehensive quantitative assessment methods and measuring standards for the consequences of dike engineering danger, resulting in poor effect of risk management and control measures for dike engineering danger. In view of this, the literature and field investigation were conducted in five aspects: identification and characterization of the occurrence environment for dike engineering danger, disaster mechanism and evolution processes of dike engineering danger, consequence analysis of dike engineering danger, risk assessment of dike engineering danger, and risk management and control of dike engineering danger. Then, the overseas and Chinese research and existing problems in the above five aspects were summarized. Furthermore, the prospective key research contents of risk assessment, as well as management and control of dike engineering danger were concluded. The research results are expected to provide important ideas and theoretical support for scientifically revealing the disaster mechanism of dike engineering danger, putting forward a practical quantitative risk assessment method for dike engineering danger, and constructing a risk-based informatization and standardized information management and control system for dike engineering.

The utilizable amount of surface water resources is the threshold value of comprehensive utilization of water resources obtained under the condition of overall living, production, and ecological water use. This concept is not unified and the calculation methods are different. The purpose of this study is to apply a relatively simple and convenient method, indirect algorithm, to calculate the surface water resources availability and reduce the difficulty of basic data collection and calculation process as much as possible. The method involves comprehensive considerations of the natural runoff situation and distribution characteristics of the basin, as well as the development, utilization, and planning of current water resources. Starting from the needs of the ecosystem, it aims to calculate the usable amount of surface water resources indirectly by calculating the target ecological water demand in the river course. Taking the Xijiang River Basin as an example, the calculated annual average utilizable amount of surface water resources from 1956 to 2016 is 45.97 × 109 m3, and the utilizable rate is 20%. Through a rational analysis, the available amount of surface water resources in the Xijiang River Basin can satisfy the increased water demand out of the basin in 2030, a target year as part of the long-term planning for the Xijiang River Basin, and meanwhile ensure ecological water demand of the basin, which can be an important basis for the revision of basin or regional planning, water allocation and scheduling, and the revision of total control indicators in the future.

Objective In the aftermath of the "5.12" Wenchuan earthquake, the frequency of chain disasters, precipitated by debris flow blockages and subsequent breaching floods, significantly increased in the Bailong River basin. The region's distinctive geological conditions, characterized by numerous towns situated on canyon terraces and debris flow accumulation fans, further exacerbate its susceptibility to such chain disasters. This study aims to investigate the potential risks associated with debris flow blockages and flood chain disasters in the Bailong River basin, with a specific focus on the Zhaizi gully debris flow in Bailong River basin, Zhouqu County, Gansu Province. The objective is to elucidate the disaster-breeding characteristics, disaster-inducing conditions, and evolution patterns of the Zhaizi gully debris flow chain disaster, while also delineating the threat range posed by these chain disasters. Methods Through remote sensing interpretation and field surveys, a comprehensive database encompassing the topography, geomorphology, and material sources of the Zhaizi gully debris flow was established. This facilitated the identification of the development characteristics and various physical and mechanical parameters of the debris flow. Using the FLO-2D and HEC-RAS models, numerical simulations were performed under different rainfall frequencies (P=1%, 2%), yielding key parameters such as depth, flow velocity, and the threat range of the debris flow and breaching floods. These parameters facilitated the analysis of hazard intensity and potential risks associated with debris flows and breaching floods. Results Under a 100-year rainfall frequency, the maximum flow velocity of the Zhaizi gully debris flow can reach 11.96 m/s. The average thickness of the debris dam formed is approximately 10 m, leading to complete blockage of the Bailong River and the formation of a dammed lake with a capacity of 6.26 km3. The evolution of the breaching flood lasts approximately 12 hours, with the peak flow occurring about 30 minutes after breach. The impact range of the breaching flood extends from the downstream area of Fengdie Town in Zhouqu County, Gannan, along the main stream of the Bailong River, to the upstream section of Jigan Township in Wudu District, Longnan City, covering an area of 56.36 km2 and spanning a distance of approximately 97.4 km. Based on the simulation results, a preliminary discussion was conducted on a comprehensive risk prevention and control model for basin-wide debris flow disaster chains, integrating monitoring and mitigation measures. Conclusion This study highlights the limitations of traditional models in flood disaster assessment and enhances the understanding of cascading hazards induced by debris flow blockages. The findings provide valuable insights for the risk assessment and engineering design of mitigation projects for similar debris flow disaster chains in the middle and lower reaches of the Bailong River basin.

Significance To analyze the research trends and frontiers in the field of groundwater-lake interaction, we conducted a comprehensive review the relevant papers from the Web of Science (WOS) database. Using VOSviewer software, we mapped the developmental trajectory of research topics in the field. Core papers from both WOS and the China National Knowledge Infrastructure (CNKI) were analyzed to systematically summarize prominent topics, research tools, and existing gaps. Based on the historical development of the field, future trends were also predicted. Progress Our analysis identified three successive developmental stages in this field, including the individualism stage, the reductionism stage, and the holism stage. Current hot research topics focus on water exchange, solute transport, and ecosystem mutual feedback mechanisms. Several key challenges remain, such as the spatiotemporal heterogeneity of groundwater-lake interactions, biogeochemical processes at the groundwater-lake interface, and the delayed impact of aquifers on lake ecological restoration. The primary research methods are stable isotopes, radioisotopes, temperature tracing, remote sensing, and numerical modelling. However, variations in data accuracy and spatial coverage continue to pose challenges for the practical application of these techniques. Conclusions and Prospects In the future, this field will enter a fourth stage characterized by big data. At this stage, it is essential to integrate diverse technological approaches, with an emphasis on using big data for high-precision monitoring to improve the characterization of dynamic groundwater-lake interactions. Additionally, multidimensional inversion models of element migration should be developed, and enhanced data mining techniques should be applied at the interface to more accurately quantify solute transport flux across the groundwater-lake interface. Finally, fostering interdisciplinary collaboration and establishing a digital ecological framework will be essential to support research on the reciprocal interactions between groundwater and lake ecosystems, promoting sustainable development and environmental protection.

Horizontal well multi-stage hydraulic fracturing technology makes the development of shale gas reservoirs efficient. However， water-rock interaction between shale rock and the work fluids like water-base drilling fluid， alkaline oil-base drilling fluid， slick-water fracturing fluid， pre-acid fluid， and oxidizing rubber breaking fluid may potentially affect wellbore stability， fracturing stimulation effect， shut-in performance， and flowback efficiency during the drilling process. This paper discusses the significance of water-rock interaction on shale gas development by systematically summarizing the mechanism of water-rock interaction and the response characteristics of shale pore structure under water-rock interaction in shale gas reservoirs in China and abroad. Shale is found rich in water-sensitive components such as clay minerals， acid-sensitive components such as carbonate minerals， alkali-sensitive components such as quartz， and oxidative-sensitive components such as organic matter and pyrite. The hydrolysis of shale components is very poor， while hydration swells and associated fracture generation due to clay minerals are prominent. The distribution of pores and fractures in shale is closely related to the chemically unstable components of quartz， carbonate minerals， organic matter， and clay minerals. Chemical dissolutions include acidizing， alkali， and oxidative dissolutions. The dissolution of shale components under water-rock action induces the dissolution and enlargement of pores and fractures， which also impairs the mechanical properties of rock. It is pointed out that optimizing working fluid， like the application of oxidative-acid and oxidative fracturing fluid， is conducive to improving the fracturing stimulation effect， promoting adsorption gas production， and improving shale gas recovery. Meanwhile， determining the maximum shut-in time based on the inflection point of the pressure drop curve and constructing the pressure control production system considering the protection of the diversion capacity of the fracture network can guide the reasonable pressure control in the whole process of gas well production， extend the stable production period， and increase the production of a single well.

In recent years, the number of patients with vaginal relaxation has increased year by year, and the minimally invasive vaginal contraction has been carried out more and more widely in clinical practice, but the treatment normalization and safety have not been thoroughly studied. We summarized six cases of characteristics and treatment measures for patients with various complications after minimally invasive vaginal contraction surgery from September 2021 to December 2023 at Department of Plastic and Aesthetic Surgery, Peking Union Medical College Hospital. The patients' age ranged from 26 to 44 years. Two cases accepted vaginal contraction with embedded vaginal thread, and four accepted vaginal contraction with acellular allogenic dermis. One patient showed vaginal hyper-tightness, one patient showed subcutaneous suture nodules, two patients showed explosion of acellular allogenic dermis, and three patients showed vaginal infection symptoms such as yellow leucorrhea and peculiar smell. All patients had sexual pain and discomfort. One patient underwent vaginal orifice dilation, one patient underwent suture extraction and secondary vaginal contraction, one patient underwent acellular allogenic dermis extraction and immediate vaginal contraction, two patients underwent acellular allogenic dermis extraction and secondary vaginal contraction, and one patient underwent secondary vaginal contraction. The symptoms of all six patients were relieved after treatment. Despite the short operation time and fast postoperative recovery of minimally invasive vaginal contraction, there are still complications after surgery, causing physical and mental damage to patients. Plastic surgeons, therefore, should be cautious in the treatment process to avoid collateral damage, so that patients get the best treatment effect.

In order that the flight vehicle group could form the expected formation, the “leader-follower” formation control law is investigated. First, the distributed extended state observer (DESO) is designed such that the followers could estimate the virtual leader’s position and velocity. Then, the expected positions of the followers are calculated based on the observer outputs and the nominal formation configuration. A dynamic surface control-based position tracking control law is designed for the followers to track the expected positions. Based on the Lyapunov theory, the stability of the proposed method is proved, while numerical simulations validate the effectiveness. The DESO could estimate both the virtual leader’s position and velocity via only the position observations. The method proposed guarantees that the orientation of the formation is consistent with the direction of the virtual leader’s velocity.

Recoil control for deepwater drilling riser system after emergency disconnection is a necessary technique in deepwater oil exploration. However, some dynamic parameters of the riser system are uncertain and difficult to measure, which poses severe challenges to the riser recoil control. Therefore, an intelligent riser recoil adaptive control method considering system uncertainties is established. Based on the nominal state-space expression of recoil control and closed-loop system stability, the modified control input considering model uncertainties is derived. The radial basis function (RBF) neural network is adopted to approximate model uncertainties, and the weight adaptive law satisfying Lyapunov stability is selected to realize dynamic compensation of uncertainties in control inputs. The results show that the proposed method is applicable to the actual recoil control valve with adjustment speed limit. The uncertainties of tensioner stiffness, damping, mud discharge friction, and riser buoyancy loads have a certain effect on recoil dynamic response and control performance. The RBF adaptive control method can effectively reduce the initial recoil oscillation height and reduce the risk of recoil bottoming. The findings can effectively solve the problem of recoil control without accurate system parameters in the engineering background.

[Purposes] The evolution of the Arctic sea ice melt pond includes the morphological change in the horizontal direction and the structural evolution in the vertical direction, but there is a few observation equipment for the vertical structure of the melt pond. In view of the problems existing in the observation of the Arctic sea ice melt pond, an automatic observation system for the vertical temperature profile of melt pond is designed. [Methods] The system is composed of observation module, power supply module, data acquisition module, data transmission module, and auxiliary module. [Findings] This system can realize continuous automatic observation of the atmosphere, snow, sea ice, melt pond, and upper ocean. The system can also provide on-site data for the verification of the results of the melt pond model, improving China’s ability to observe the rapid changes of the Arctic sea ice, and has important engineering application value.

[Purposes] In order to better understand the permeability changes of coal measure bedded sandy mudstone under stress, the mechanical characteristics and permeability of bedded sandy mudstone were studied by discrete element simulation on the basis of the stress seepage coupling laboratory tests. [Methods] First, the failure mode and the relationship between the full stress-strain loading process and the permeability of sandy mudstone were studied by the stress-seepage coupling laboratory tests in the bedding directions of parallel and perpendicular rock bedding. Second, in the discrete element software PFC2D, a method to characterize the flow field by solving the finite difference method is proposed for the first time, which can well reflect the stress-strain response and permeability changes of sandy mudstone, and the simulated stress-strain and permeability curves obtained are consistent with experimental results, with the fluid flowing intensively along the main fracture. Finally, according to the calibrated parameters, the stress and permeability of rock samples at different bedding angles are simulated, and the relationships between the maximum permeability or peak strength and bedding angles are explored. [Findings] The results show that the strength and permeability of layered sandy mudstone are anisotropic. The flow field direction, flow rate, and contact force chain in the rock sample are closely related to the crack, and the strong contact force chain is concentrated near the shear zone at the joint of the sample. With the increase of the bedding angle α, the peak intensity changes in a“ U” shape, and the maximum permeability decreases linearly. [Conclusions] This numerical simulation method fully takes into account the influence of rock mechanics and seepage characteristics, which provides a theoretical basis for the surrounding rock seepage prevention and reinforcement project, and a new idea for the fluid-structure interaction of discrete element simulation.

In urgent demand for high-performance cryogenic titanium alloy for the heavy-lift launch vehicle， a novel 1500 MPa Ti-Al-V-Zr-Mo-Nb cryogenic titanium alloy （CT1400） was designed. Alloy bars and powder metallurgy materials of CT1400 were fabricated， and the microstructure， tensile properties， and cryogenic tensile deformation mechanism were also observed and analyzed. The results indicate that the CT1400 cryogenic titanium alloy mainly consists of α phase and a small quantity of β phase， which shows a typical near-α type cryogenic titanium alloy. CT1400 alloy bars display the apparent equiaxed fine-grain microstructure characteristic， and the powder metallurgy materials show the dominating lamellar microstructure combing with the “network” structure characteristic. CT1400 titanium alloys display excellent room and cryogenic tensile properties， which can stably reach cryogenic stress of 1500 MPa resulting from dislocation strengthening and grain boundary strengthening mechanisms. Furthermore， the twinning deformation at the cryogenic temperature of 20 K could additionally improve the cryogenic plastic deformation capacity of CT1400 titanium alloy by coordinating crystal orientation， promoting strain hardening， making it represent excellent coupling of strength and ductility at cryogenic temperatures.