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Research on the macro-and meso-mechanical properties of frozen sand mold based on Hertz-Mindlin with Bonding model

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Particuology 2024年第5期88卷 176-191页

作者： Jianpei Shi Zhongde shan Haoqin Yang College of Mechanical and Electrical Engineering Nanjing University of Aeronautics and AstronauticsNanjing 210016China State Key Laboratory of Mechanics and Control of Mechanical Structures Nanjing University of Aeronautics and AstronauticsNanjing 210016China College of Material Science and Technology Nanjing University of Aeronautics and AstronauticsNanjing 210016China

In this study,macro-and meso-mechanical properties of frozen sand molds were discussed based on the Hertz-Mindlin with Bonding(HMB)***-Burman,steepest ascent,and central composite designs were utilized to propose a parameter calibration *** effects of mesoscopic parameter variations on the compressive strength and average gradient of stress-strain were investigated through response surface method *** showed that the relative error between the simulated and measured repose angle is 3.1%under calibrated intrinsic contact *** compressive strength and average stress-strain gradient primarily depend on the normal and shear stiffness per unit area,as well as the particle size and porosity of the silica ***,taking load-displacement curves of three frozen sand molds with different geometric characteristics as the target value,the reliability and effectiveness of the frozen sand mold HMB model were verified through uniaxial compression tests and discrete element simulations.

关键词： Frozen sand mold Hertz-Mindlin with Bonding model Uniaxial compression test Discrete element method Mechanical properties

Field survey and analysis on near-fault severely damaged high-speed railway bridge in 2022 M6.9 Menyuan earthquake

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Earthquake Engineering and Engineering Vibration 2024年第4期23卷 1043-1055页

作者： Lin Xuchuan Liu Fuxiang shan Wenchen Key Laboratory of Earthquake Engineering and Engineering Vibration Institute of Engineering MechanicsChina Earthquake AdministrationHarbin 150080China Key Laboratory of Earthquake Disaster Mitigation Ministry of Emergency ManagementHarbin 150080China Institute of Smart City and Intelligent Transportation Southwest Jiaotong UniversityChengdu610000China

The 2022 M6.9 Menyuan earthquake caused severe damage to a high-speed railway bridge,which was designed for high-speed trains running at speeds of above 250 km/h and is located right next to the *** of this type have been widely used for rapidly constructing the high-speed railway network,but few bridges have been tested by near-fault devastating *** potential severe impact of the earthquake on the high-speed railway is not only the safety of the infrastructure,trains and passengers,but also economic loss due to interrupted railway ***,a field survey was carried out immediately after the earthquake to collect time-sensitive *** damage to the bridge was carefully investigated,and quantitative analyses were conducted to better understand the mechanism of the bridge *** was found that seismic action perpendicular to the bridge’s longitudinal direction caused severe damage to the girders and rails,while none of the piers showed obvious deformation or *** maximum values of transverse displacement,out-of-plane rotation and twisting angle of girders reached 212.6 cm,3.1 degrees and 19.9 degrees,respectively,causing severe damage to the bearing supports and anti-seismic retaining *** observations provide a basis for improving the seismic design of high-speed railway bridges located in near-fault areas.

关键词： Menyuan earthquake field survey high-speed railway bridge near fault seismic damage

Facet effects on bimetallic ZnSn hydroxide microcrystals for selective electrochemical CO2 reduction

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Green Energy & Environment 2024年第8期9卷 1314-1320页

作者： Liu Han Cheng-wei Wang shan-shan Luo Ying-tang Zhou Bing Li Ming Liu School of Chemistry and Chemical Engineering Harbin Institute of Technology National Engineering Research Center for Marine Aquaculture Marine Science and Technology CollegeZhejiang Ocean University

Employing crystal facets to regulate the catalytic properties in electrocatalytic carbon dioxide reduction reaction（eCO2RR） has been well demonstrated on electrocatalysts containing single metals but rarely explored for bimetallic systems. Here, we synthesize Zn Sn（OH）6（ZSO）microcrystals（MCs） with distinct facets and investigate the facet effects in eCO2RR. Electrochemical studies and in situ Fourier Transform Infrared Spectroscopy（in situ-FTIR） reveal that ZSO MCs produce mainly C1 products of HCOOH and CO. The {111} facet of the ZSO MCS exhibits higher selectivity and faradaic efficiency（FE） than that of the {100} facet over a wide range of potentials（-0.9 V ～-1.3 V versus RHE）. Density Functional Theory（DFT） calculations elucidate that the {111} facet is favorable to the adsorption/activation of CO2molecules,the formation of intermediate in the rate-determining step, and the desorption of C1 products of CO and HCOOH molecules.

关键词： ZnSn(OH) 6 Crystal facets Electrochemical carbon dioxide reduction C1 product Density functional theory

Greedy Lattice Paths with General Weights

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Acta Mathematica Sinica,English Series 2024年第9期40卷 2213-2222页

作者： Yin shan CHANG An Qi ZHENG College of Mathematics Sichuan UniversityChengdu 610065P.R.China

Let{X_(v):v∈Z^(d)}be *** *** S(π)=Σ_(v∈π)X_(v)be the weight of a self-avoiding lattice pathπ.Let M_(n)=max{S(π):πhas length n and starts from the origin}.We are interested in the asymptotics of Mn as n→∞.This model is closely related to the first passage percolation when the weights{X_(v):v∈Z^(d)}are non-positive and it is closely related to the last passage percolation when the weights{X_(v):v∈Z^(d)}are *** general weights,this model could be viewed as an interpolation between first passage models and last passage ***,this model is also closely related to a variant of the position of right-most particles of branching random *** the two assumptions that∃α>0,E(X_(0)^(+))^(d)(log^(+)X_(0)^(+))^(d+α)0,E(X_(0)^(+))^(d)(log^(+)X_(0)^(+))^(d+α)<+∞and that E[(X_(0)^(−))^(4)]<+∞,we prove that M_(n)/n converges to the same constant M almost surely as n tends to infinity.

关键词： Last passage percolation first passage percolation greedy lattice path

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基于CPLD的SF_6微量气体浓度检测仪

仪器仪表学报 2005年第Z1期26卷 448-449页

作者：朱昌平单鸣雷刘永富张红苹河海大学计信学院

通过综合应用复杂可编程逻辑器件(CPLD)与超声技术,实现了可实时监控的SF6微量气体浓度检测仪的研制,精度可达50ppm,与传统的SF6微量气体浓度检测仪相比,该仪器具备操作简便、价格便宜等优点。仪器核心内容已分别申报发明(200510037936... 详细信息

通过综合应用复杂可编程逻辑器件(CPLD)与超声技术,实现了可实时监控的SF6微量气体浓度检测仪的研制,精度可达50ppm,与传统的SF6微量气体浓度检测仪相比,该仪器具备操作简便、价格便宜等优点。仪器核心内容已分别申报发明(200510037936.2)和实用新型专利(200520069403.8),已在进行产品生产。

关键词： CPLD 超声技术SF6浓度检测

Study on Enhancement Effect of Cavitation Caused by HIFU Piezoelectricity Transducer

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稀有金属材料与工程 2006年第S3期 527-529页

作者： Xinnan Fan~1 Changping Zhu~1 Shichuan He~2 minglei shan~2 Jiacai Chen~2 (1.Department of Computer & Information Engineering,Hohai University,Changzhou 213022,China) (2.State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering,Hohai University,Nanjing 210098,China)

An orthogonal ultrasonic irradiation system consisting of HIFU with frequency at 1.05 MHz combined with ultrasound with frequency at 28 kHz was applied in this *** of cavitation was detected by pH-value measurement and conductance *** result shows that the effect of cavitation caused by ultrasound with frequency at 28 kHz is greatly enhanced by HIFU piezoelectricity transducer with frequency at 1.05 MHz.

关键词： HIFU piezoelectricity transducer enhanced cavitation effect orthogonal ultrasonic irradiation

大学生社交焦虑、归因方式、乐观取向与羞怯的关系研究

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山东青年政治学院学报 2014年第5期30卷 62-66页

作者：单铭磊山东青年政治学院山东济南250014

本研究结合调查问卷,对大学生羞怯与社交焦虑、归因方式、乐观取向之间的关系进行分析。提出了两个可能影响羞怯对社交焦虑预测的因素:归因方式和乐观取向,构建了羞怯、社交焦虑、归因方式和乐观取向四者相互作用的假设模型,并对模型进... 详细信息

本研究结合调查问卷,对大学生羞怯与社交焦虑、归因方式、乐观取向之间的关系进行分析。提出了两个可能影响羞怯对社交焦虑预测的因素:归因方式和乐观取向,构建了羞怯、社交焦虑、归因方式和乐观取向四者相互作用的假设模型,并对模型进行了检验。研究揭示了羞怯与归因方式、乐观取向和社交焦虑之间的相互关系,发现归因方式与乐观取向在羞怯与社交焦虑之间起双中介作用:一方面羞怯直接影响社交焦虑,另一方面羞怯通过影响归因方式影响乐观取向,进而影响社交焦虑。

关键词：大学生羞怯社交焦虑归因方式乐观取向

旅游管理学科“三实一体、分层递进”全真实践教学模式研究

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山东商业职业技术学院学报 2020年第3期20卷 43-46,50页

作者：单铭磊山东青年政治学院山东济南250031

在旅游管理学科全真实景实践教学的大趋势下,实验、实训、实习的一体化改革将进一步促进校企合作以及科教协同对人才培养的贡献。并且随着产教融合的深入,这种一体化在全真实景实践条件下会更加有效地保障知识产能分层次、分步骤地向生... 详细信息

在旅游管理学科全真实景实践教学的大趋势下,实验、实训、实习的一体化改革将进一步促进校企合作以及科教协同对人才培养的贡献。并且随着产教融合的深入,这种一体化在全真实景实践条件下会更加有效地保障知识产能分层次、分步骤地向生产产能推进和转变。

关键词：三实一体分层递进全真实践教学旅游管理学科

The role of m^(6)A RNA methylation in autoimmune diseases: Novel therapeutic opportunities

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Genes & Diseases 2024年第1期11卷 252-267页

作者： Yunan shan Wei Chen Yanbin Li The First Clinical Medical College Shandong University of Traditional Chinese MedicineJinanShandong 250013China Department of Neurology The First Affiliated Hospital of Shandong First Medical University&Shandong Provincial Qjanfoshan HospitalShandong Institute of NeuroimmunologyShandong Key Laboratory of Rheumatic Disease and Translational MedicineJinanShandong 250013China Department of Gastroenterology Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of MedicineShanghai 200233China

N6-methyladenosine m^(6)A modifications,as one of the most common forms of in-ternal RNA chemical modifications in eukaryotic cells,have gained increasing attention in recent *** m^(6)A RNA modifications exert various crucial roles in various biological pro-cesses,such as embryonic development,neurogenesis,circadian rhythms,and *** advances have highlighted that m^(6)A RNA modification plays an important role in im-mune response,especially in the initiation and progression of autoimmune *** this re-view,we summarized the regulatory mechanisms of m^(6)A methylation and its biological functions in the immune system and mainly focused on recent progress in research on the po-tential role of m^(6)A RNA methylation in the pathogenesis of autoimmune diseases,thus providing possible biomarkers and potential targets for the prevention and treatment of auto-immunediseases.

关键词： Adaptive immunity Autoimmune diseases Innate immunity Immune response m^(6)A RNA methylation