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Numerical simulation on sand sedimentation and erosion characteristics around HDPE sheet sand barrier under different wind angles

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Journal of Mountain Science 2024年第2期21卷 538-554页

作者： zhang Kai zhang Peili zhang hailong TIAN Jianjin WANG Zhenghui XIAO Jianhua College of Civil Engineering Lanzhou Jiaotong UniversityLanzhou 730000China Key Laboratory of Desert and Desertification Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 730000China Key Laboratory of Ecological Safety and Sustainable Development in Arid Lands Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 730000China

For the safety of railroad operations,sand barriers are utilized to mitigate wind-sand disaster *** disasters,characterized by multi-directional wind patterns,result in diverse angles among the *** this study,using numerical simulations,we examined the behavior of High Density Polyethylene(HDPE)sheet sand barriers under different wind angles,focusing on flow field distribution,windproof efficiency,and sedimentation erosion *** study discovered that at a steady wind speed,airflow velocity varies as the angle between the airflow and the HDPE barrier ***,a 90°angle results in the widest low-speed airflow area on the barrier’s downwind *** the airflow is not perpendicular to the barrier,it prompts a lateral airflow movement which decreases as the angle *** windproof efficiency correlates directly with this angle but inversely with the wind’s ***,with a wind angle of 90°,wind speed drops by 81%.The minimum wind speed is found at 5.1H(the sand barrier height)on the barrier’s downwind *** the angle grows,the barrier’s windproof efficiency improves,extending its protective *** is most prominent on the barrier’s downwind side,as the wind angle shifts from 30°to 90°,the sand sedimentation area on the barrier’s downwind side enlarges by *** the angle grows,sedimentation intensifies,eventually overtakes the forward erosion and enlarges the sedimentation area.

关键词： Multi-wind direction HDPE sheet sand barrier Numerical simulation Windproof efficiency Sedimentation erosion

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Numerical simulation of flow field deposition and erosion characteristics around bridge-road transition section

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Journal of Mountain Science 2024年第5期21卷 1491-1508页

作者： zhang Kai WANG Zhenghui WANG Tao TIAN Jianjin zhang hailong LIU Yonghe College of Civil Engineering Lanzhou Jiaotong UniversityLanzhou 730000China Key Laboratory of Desert and Desertification Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 730000China

Wind-sand flow generates erosion and deposition around obstacles such as bridges and roadbeds, resulting in sand damage and endangering railway systems in sandy regions. Previous studies have mainly focused on the flow field around roadbeds, overlooking detailed examinations of sand particle erosion and deposition patterns near bridges and roadbeds. This study employs numerical simulations to analyze the influence of varying heights and wind speeds on sand deposition and erosion characteristics at different locations: the bridge-road transition section(side piers), middle piers, and roadbeds. The results show that the side piers, experience greater accumulation than the middle piers. Similarly, the leeward side of the roadbed witnesses more deposition compared to the windward side. Another finding reveals a reduced sand deposition length as the vertical profile, in alignment with the wind direction, moves further from the bridge abutments at the same clearance height. As wind speeds rise, there’s a decline in sand deposition and a marked increase in erosion around the side piers, middle piers and roadbeds. In conclusion, a bridge clearance that’s too low can cause intense sand damage near the side piers, while an extremely high roadbed may lead to extensive surface sand deposition. Hence, railway bridges in areas prone to sandy winds should strike a balance in clearance height. This research provides valuable guidelines for determining the most suitable bridge and roadbed heights in regions affected by wind and sand.

关键词： Sandstorm Flow field Bridge-road transition section Sedimentation erosion Numerical simulation

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Flow field, sedimentation, and erosion characteristics around folded linear HDPE sheet sand fence: Numerical simulation study

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Journal of Mountain Science 2024年第1期21卷 113-130页

作者： zhang Kai zhang hailong TIAN Jianjin QU Jianjun zhang Xingxin WANG Zhenghui XIAO jianhua College of Civil Engineering Lanzhou Jiaotong UniversityLanzhou 730000China Key Laboratory of Desert and Desertification Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 730000China College of Civil Engineering Chongqing UniversityChongqing 400045China Key Laboratory of Ecological Safety and Sustainable Development in Arid Lands Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 730000China

Wind and sand hazards are serious in the Milan Gobi area of the Xinjiang section of the Korla Railway. In order to ensure the safe operation of railroads, there is a need for wind and sand protection in heavily sandy areas. The wind and sand flow in the region is notably bi-directional. To shield railroads from sand, a unique sand fence made of folded linear high-density polyethylene(HDPE) is used, aligning with the principle that the dominant wind direction is perpendicular to the fence. This study employed field observations and numerical simulations to investigate the effectiveness of these HDPE sand fences in altering flow field distribution and offering protection. It also explored how these fences affect the deposition and erosion of sand particles. Findings revealed a significant reduction in wind speed near the fence corner;the minimum horizontal wind speed on the leeward side of the first sand fence(LSF) decreased dramatically from 3 m/s to 0.64 m/s. The vortex area on the LSF markedly impacted horizontal wind speeds. Within the LSF, sand deposition was a primary occurrence. As wind speeds increased, the deposition zone shrank, whereas the positive erosion zone expanded. Close to the folded corners of the HDPE sand fence, there was a notable shift from the positive erosion zone to a deposition zone. Field tests and numerical simulations confirmed the high windproof efficiency(WE) and sand resistance efficiency(SE) in the HDPE sand fence. Folded linear HDPE sheet sand fence can effectively slow down the incoming flow and reduce the sand content, thus achieving good wind and sand protection. This study provides essential theoretical guidance for the design and improvement of wind and sand protection systems in railroad engineering.

关键词： Folded linear HDPE sheet sand fence Numerical simulation Flow field characteristics Protection benefits

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Protective benefit of folded linear HDPE board sand fences along the Golmud-Korla Railway,China:Field observation and wind tunnel study

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Journal of Mountain Science 2024年第7期21卷 2206-2219页

作者： zhang Kai TIAN Jianjin WANG Zhenghui zhang hailong zhang Xingxin College of Civil Engineering Lanzhou Jiaotong UniversityLanzhou 730000China Key Laboratory of Desert and Desertification Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 730000China College of Civil Engineering Chongqing UniversityChongqing 400045China

The Milan Gobi area of the Golmud-Korla Railway in northwest China is located in the lower dispersal area of the mountain pass and has strong winds with evident double wind direction *** study introduced a novel sand fence deployment technique,termed‘folded linear deployment',designed to position the sand fence orthogonally to the two predominant wind directions for optimal *** study used wind tunnel and field tests to evaluate the wind and sand flow characteristics,as well as the windproof and sandresistant performance of folded linear HDPE(Highdensity polyethylene)board sand *** results suggest that the airflow around the fence creates clear zoning *** deceleration area on the BSF(backwind side of the sand fence)is much larger than that on the DSF(downwind side of the sand fence).Thus,sand particles are primarily deposited on the *** different wind speeds,the airflow at 2 and 5 h on the DSF is not *** WSP(wind speed profile)presents a logarithmic *** airflow is disturbed at 1-20 h on the BSF,and the WSP gradually deviates from the logarithmic ***,as the airflow moves away from the fence,the WSP gradually approaches a logarithmic ***,the WPE(windproof efficiency)and SRE(sand-resistant efficiency)of the sand fence exceed 80%.In addition,the results of wind tunnel tests are compared with those of field *** overall dispersion is good,and the best dispersion is found at z/H=2.00,indicating good agreement between the two test *** study provides a scientific basis for the design of sand hazard control measures,similar to the railway project in the Gobi Gale area.

关键词： Folded linear HDPE board sand fence Double wind direction Gobi area Protection benefit

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Characterization of alpine meadow surface crack and its correlation with root-soil properties

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Journal of Arid Land 2024年第6期16卷 834-851页

作者： WU Yuechen ZHU Haili zhang Yu zhang hailong LIU Guosong LIU Yabin LI Guorong HU Xiasong School of Geological Engineering Qinghai UniversityXining 810016China Key Laboratory of the Cenozoic Resources and Environment on the North Rim of the Qinghai-Tibet Plateau Xining 810016China Qinghai Provincial Transportation Planning and Design Research Institute Co.Ltd. Xining 810002China

Quantifying surface cracks in alpine meadows is a prerequisite and a key aspect in the study of grassland crack *** characterization indices are crucial for the quantitative characterization of complex cracks,serving as vital factors in assessing the degree of cracking and the development *** far,research on evaluating the degree of grassland degradation through crack characterization indices is rare,especially the quantitative analysis of the development of surface cracks in alpine meadows is relatively ***,based on the phenomenon of surface cracking during the degradation of alpine meadows in some regions of the Qinghai-Tibet Plateau,we selected the alpine meadow in the Huangcheng Mongolian Township,Menyuan Hui Autonomous County,Qinghai Province,China as the study area,used unmanned aerial vehicle(UAV)sensing technology to acquire low-altitude images of alpine meadow surface cracks at different degrees of degradation(light,medium,and heavy degradation),and analyzed the representative metrics characterizing the degree of crack development by interpreting the crack length,length density,branch angle,and burrow(rat hole)distribution density and combining them with in situ crack width and depth ***,the correlations between the crack characterization indices and the soil and root parameters of sample plots at different degrees of degradation in the study area were analyzed using the grey relation *** results revealed that with the increase of degradation,the physical and chemical properties of soil and the mechanical properties of root-soil composite changed significantly,the vegetation coverage reduced,and the root system aggregated in the surface layer of alpine *** the degree of degradation increased,the fracture morphology developed from"linear"to"dendritic",and eventually to a complex and irregular"polygonal"*** crack length,width,depth,and length density were identified as the crack char

关键词： alpine meadow grassland degradation grassland cracks crack characterization index crack morphology root length density grey relation analysis

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Comparative Study on Microstructure and Mechanical Properties of Coarse-grained WC-based Cemented Carbides Sintered with Ultrafine WC or (W+C) as Additives

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Journal of Wuhan University of Technology(Materials Science) 2024年第2期39卷 399-409页

作者：于淞百闵凡路 LI De NOUDEM Guillaume Jacques zhang hailong MA Jichang ZHAO Kui YAO Zhanhu 张建峰 College of Mechanics and Materials Hohai UniversityNanjing 210098China Key Laboratory of Geomechanics and Embankment Engineering Hohai UniversityMinistry of EducationNanjing 210098China CRISMAT-ENSICAEN(UMR-CNRS 6508) Universitéde Caen-Basse-NormandieF-14050 CaenFrance Shaanxi Aeronautic Carbide Tool Co.Ltd. Hanzhong 724200China CCCC Tunnel Engineering Co.Ltd. Beijing 100102China

The effects of ultrafine WC(WC_(UF),0.5μm) or W(1μm) and C(0.3μm)(W+C)_(UF) additives on the densification,microstructure and mechanical properties of coarse-grained cemented carbides were compared ***,the cemented carbides with WC_(UF)/(W+C)_(UF) additives are almost fully densification to be higher than 99%,and the average grain size is kept above 2.8μ*** WC_(UF) additive assists grains to(truncated)trigonal prism shape by two dimensional(2D) growth,whereas the(W+C)_(UF) additive assists grains to rounded shape by three dimensional(3D) growth,lowers WC contiguity and increases face-centered-cubic *** hardness and bending strength of(75WC_(C)-15WC_(UF))-10Co are 86.6 HRA and 2 272 MPa,respectively,both higher than those of(75WC_(C)-15(W+C)_(UF))-10Co,which could be ascribed to the enhanced densification and unblemished ***,the fracture toughness of the(75WC_(C)-15(W+C)_(UF))-10Co is 23.5 MPa·m^(1/2),higher than that of the(75WC_(C)-15WC_(UF))-10Co due to the uniform WC-Co structure and flexible binder phase.

关键词： coarse-grained WC-based cemented carbide ultrafine WC ultrafine(W+C) microstructure mechanical properties

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Analysis and Key Parameter Optimization Design of Leningrader Seal Performance

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Wuhan University Journal of Natural Sciences 2024年第2期29卷 177-192页

作者： YANG Dongya WANG Xuelin WANG Feng zhang hailong GAO Gui College of Mechanical and Electrical Engineering Lanzhou University of TechnologyLanzhou 730050Gansu China Wenzhou Pump and Valve Engineering Research Institute Lanzhou University of TechnologyWenzhou 325000ZhejiangChina State Key Laboratory of Solid Lubrication Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou 730000GansuChina

In order to improve the performance and service life of the Leningrader seal of the Stirling engine piston rod,interference,pre-load and friction coefficient were taken as influencing factors,and the curved surface response method was adopted to reduce the contact stress of sealing surface and von Mises stress of the sealing sleeve as the response index,with the optimization goal of reducing wear and extending *** above three key parameters are analyzed and optimized,the influence of each parameter on the sealing performance and service life is obtained,and the best combination scheme of the three is *** results show that the interaction between pre-tightening force and interference fit has the greatest impact on contact *** interaction between interference fit and friction coeffi-cient has the most significant effect on von Mises *** optimized parameters can reduce the maximum contact stress and maximum von Mises stress of the sealing sleeve by 26.3%and 20.6%,respectively,under a media pressure of 5-9 *** bench verification shows that the leakage of the optimized sealing device in 12 h is reduced by 0.44 cc·min^(-1)(1 cc=1 cm^(3)).The wear rate of the sealing sleeve is 1.08%before optimization and 0.45%after optimization,indicating that the optimized parameters in this paper are effective.

关键词： Leningrader seal Stirling engine performance analysis optimized design parameter configuration

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癌-睾丸抗原SPANXB在肝癌中的表达及其影响肝癌进展的机制研究

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上海交通大学学报(医学版) 2024年第7期44卷 801-813页

作者：薛煜张海龙雷鸣上海交通大学医学院附属第九人民医院上海精准医学研究院上海交通大学转化医学研究院

目的·分析癌-睾丸抗原（cancer-testis antigen,CTA）家族成员SPANXB (sperm protein associated with the nucleus on the X chromosome B)在肝癌中的表达及其与肝癌患者预后之间的相关性，并探究SPANXB对肝癌细胞增殖的影响及其潜在... 详细信息

目的·分析癌-睾丸抗原（cancer-testis antigen,CTA）家族成员SPANXB (sperm protein associated with the nucleus on the X chromosome B)在肝癌中的表达及其与肝癌患者预后之间的相关性，并探究SPANXB对肝癌细胞增殖的影响及其潜在机制。方法·利用癌症基因组图谱（The Cancer Genome Atlas,TCGA）数据库中的肝癌样本数据，分析SPANXB在肝癌组织中的表达及其与患者生存期的相关性。构建稳定敲低SPANXB与稳定过表达SPANXB的肝癌细胞系，利用活细胞成像实验、EdU细胞增殖实验和平板克隆形成实验评估SPANXB对肝癌细胞增殖的影响。通过RNA测序（RNA-sequence,RNA-seq）探究SPANXB调控肝癌细胞增殖的相关通路，并利用细胞周期实验验证SPANXB对肝癌细胞周期的影响。采用免疫沉淀-质谱联用技术（immunoprecipitation-mass spectrometry,IP-MS）探索与SPANXB相互作用的蛋白，并使用免疫共沉淀（co-immunoprecipitation,Co-IP）进行验证。结果·SPANXB mRNA在肝癌组织中的表达高于正常组织（P=0.003），且与肝癌患者的生存期呈负相关。稳定敲低SPANXB可降低肝癌细胞的增殖能力、克隆形成能力，而稳定过表达SPANXB则可促进这些过程。RNA-seq的结果显示，SPANXB的敲低可下调DNA复制与G1/S细胞周期转换相关通路，细胞周期实验的结果显示SPANXB的敲低可导致肝癌细胞周期发生改变。IP-MS和Co-IP结果显示，SPAXNB与有丝分裂停滞缺陷2样蛋白1 (mitotic arrest deficient 2-like protein 1,MAD2L1)、WD重复域蛋白5 (WD repeat domain 5,WDR5)等细胞周期相关蛋白存在相互作用。结论·SPANXB的高表达与肝癌的预后呈负相关，其可能通过与MAD2L1、WDR5相互作用调控细胞周期并增强肝癌细胞的增殖活性。

关键词：癌-睾丸抗原 SPANXB 肝癌细胞周期

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Review of artificial intelligence applications in astronomical data processing

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Astronomical Techniques and Instruments 2024年第1期1卷 1-15页

作者： hailong zhang Jie Wang Yazhou zhang Xu Du Han Wu Ting zhang Xinjiang Astronomical Observatory Chinese Academy of SciencesUrumqi 830011China University of Chinese Academy of Sciences Beijing 100049China Key Laboratory of Radio Astronomy Chinese Academy of SciencesNanjing 210008China National Astronomical Data Center Beijing 100101China

Artificial Intelligence(AI)is an interdisciplinary research field with widespread *** aims at developing theoretical,methodological,technological,and applied systems that simulate,enhance,and assist human ***,notable accomplishments of artificial intelligence technology have been achieved in astronomical data processing,establishing this technology as central to numerous astronomical research areas such as radio astronomy,stellar and galactic(Milky Way)studies,exoplanets surveys,cosmology,and solar *** article systematically reviews representative applications of artificial intelligence technology to astronomical data processing,with comprehensive description of specific cases:pulsar candidate identification,fast radio burst detection,gravitational wave detection,spectral classification,and radio frequency interference ***,it discusses possible future applications to provide perspectives for astronomical research in the artificial intelligence era.

关键词： Astronomical techniques Astronomical methods Astroinformatics

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Pursuing the goal of carbon neutrality in China:path for realization of carbon sequestration in planted forests

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Frontiers of Agricultural Science and Engineering 2024年第3期11卷 355-366页

作者： Lei DENG Haitao HU Jiwei LI Xue LI Chunbo HUANG Zhijing YU hailong zhang Qing QU Xiaozhen WANG Lingbo DONG Zhouping SHANGGUAN State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau Northwest A&F UniversityYangling 712100China College of Soil and Water Conservation Science and Engineering(Institute of Soil and Water Conservation) Northwest A&F UniversityYangling 712100China Shaanxi Forestry Survey and Planning Institute Xi’an 710000China College of Landscape Architecture Northeast Forestry UniversityHarbin 150040China Institute of Soil and Water Conservation Chinese Academy of Sciences and Ministry of Water ResourcesYangling 712100China Key Laboratory of Regional Ecology and Environmental Change School of Geography and Information EngineeringChina University of GeosciencesWuhan 430074China

Tree plantations are an important forest resource that substantively contributes to climate change mitigation and carbon *** the area and standing volume of tree plantations in China have increased,issues such as unreasonable structure,low productivity,limited ecological functionality and diminishing ecological stability have occurred,which hinder the ability of tree plantations to enhance carbon *** study outlined the trajectory of carbon sequestration and its associated benefits in tree plantations by examining the current state of tree plantation establishment and growth,elucidated the strategies for advantages of carbon sequestration and climate change mitigation in planted forests,and summarized the existing problems with tree *** paper underscores the pressing need for concerted efforts to boost carbon sequestration within planted forests and proposes management and development strategies for Chinese tree *** the future,it will be necessary to apply scientific theories to practice and develop multi-objective management optimization models for the high-quality development of tree *** will involve establishing a cohesive national carbon trading market,improving the prediction of carbon sequestration,and identifying priority zones for afforestation and reforestation,to better serve China’s national strategy for achieving peak carbon and carbon neutrality.

关键词： Planted forest carbon stock carbon sequestration carbon management climate change promotion path

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