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城市公共交通出行规律探析与发展建议

公路 2024年第9期69卷 177-185页

作者：刘芳亮宋国华吴亦政中交公路规划设计院有限公司北京市100010 北京交通大学交通运输学院北京市100044

城市公共交通被认为是缓解交通拥堵、提高城市居民生活质量、加快城市内部人口流动最为有效的方式之一。近年来,随着新业态的出现,城市公共交通却面临一系列挑战与难题,而挖掘城市公共交通乘客出行规律对掌握乘客出行特点与需求、改善... 详细信息

城市公共交通被认为是缓解交通拥堵、提高城市居民生活质量、加快城市内部人口流动最为有效的方式之一。近年来,随着新业态的出现,城市公共交通却面临一系列挑战与难题,而挖掘城市公共交通乘客出行规律对掌握乘客出行特点与需求、改善公交服务水平、破解城市公交发展瓶颈局面具有重要意义。通过对北京市城市公共交通刷卡大数据的深入挖掘,从出行量、出行天数、出行次数、出行链、出行空间、职住地等角度对乘客出行特征进行全方面、多角度分析,并据此为改善公交发展现状、提升服务水平针对性地提出改进建议。

关键词：城市公共交通大数据分析出行特征职住地识别

Further Oscillation Results for a Class of Hyperbolic Equations with Continuous Distributed Deviating Arguments

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Chinese Quarterly Journal of Mathematics 2012年第1期27卷 145-151页

作者： ZHANG Meng song guo-hua College of Forest Beijing Forestry UniversityBeijing 100083China School of Science Beijing University of Civil Engineering and ArchitectureBeijing 100044China

A class of hyperbolic equations with continuous distributed deviating arguments is considered and its oscillation theorems are *** theorems are of higher degree of generality and deal with the cases which are not cove... 详细信息

关键词： oscillation criteria hyperbolic equations continuous distributed deviating arguments

Identification and characteristics analysis of bottlenecks on urban expressways based on floating car data

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Journal of Central South University 2018年第8期25卷 2014-2024页

作者： ZHANG Jian-bo song guo-hua YU Lei guo Ji-fu LU Hong-yu School of Traffic and Transportation Beijing Jiaotong UniversityBeijing 100044China College of Science Engineering and TechnologyTexas Southern UniversityHouston 77004USA Beijing Transport Institute Beijing 100073China

Identifying bottlenecks and analyzing their characteristics are important tasks to city traffic management *** the speed difference was proposed for the bottleneck identification in the existing research,the use of a secondary indicator has not been fully *** paper strived to develop a method to identify the bottleneck on expressways by using the massive floating car data(FCD)in ***,the speed characteristics of bottlenecks on expressway were analyzed based on the speed contour *** results indicated that there was a significant difference between speeds on the bottleneck and downstream links when a bottleneck was *** speed difference could indeed be used as the primary indicator to identify the ***,it was also shown that a sufficiently large speed difference does not necessitate an activation of a *** speed-at-capacity was then used as the secondary indicator to distinguish the real bottleneck from the non-bottleneck speed ***,a practical method for identifying the bottleneck on expressways was developed based on the speed difference and the ***,the method was applied to identifying the bottlenecks of the 3rd Outer Ring Expressway in *** duration,affected distance,delay and cause were used to evaluate and analyze the bottlenecks.

关键词： urban expressway bottleneck identification speed difference speed-at-capacity

Effect of cerium on microstructure,texture and properties of ultrahigh-purity copper

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Journal of Rare Earths 2024年第1期42卷 220-227,I0008页

作者： Yunxiao hua Haitao Liu Kexing song Jiangwei Wang Yin'gang guo Jing Tian Huiwen guo Provincial and Ministerial Co-construction of Collaborative Innovation Center for Non-ferrous Metal New Materials and Advanced Processing Technology School of Materials Science and EngineeringHenan University of Science and TechnologyLuoyang471023China Henan Academy of Sciences Zhengzhou450000China Center of Electron Microscopy and State Key Laboratory of Silicon Materials School of Materials Science and EngineeringZhejiang UniversityHangzhou310027China Henan Zhongyuan Gold Smelter Co. Ltd.Sanmenxia472100China Chinalco Luoyang Copper Processing Co. Ltd.Luoyang471039China

The effects of Ce addition(310 ppm and 1500 ppm)on the microstructure,texture and properties of ultrahigh-purity copper(99.99999%)were systematically studied using scanning electron microscopy(SEM),transmission electron microscopy(TEM)and electron backscattered diffraction(EBSD)analyses,combined with the microhardness and conductivity *** the microstructure of the as-cast and as-extruded samples,the addition of Ce refines the grain size of the ultrahigh-purity copper and the refinement effect of 310Ce alloy is greater than that of 1500Ce *** is due to the stronger compone nt supercooling and the accele rated recrystallization caused by lower Ce co *** addition,Ce can react with Cu to form the Cu-Ce eutectic phases,which are deformable during the hot ***,the added Ce can weaken the texture,showing a variation of brass recrystallization(BR),rotated cube,copper and S texture components,which depends on the recrystallization,the particle stimulated nucleation(PSN)as well as the stacking fault energy(SFE).Most remarkably,the introduction of Ce enhances the hardness of the ultrahigh-purity copper without obviously reducing its *** major{111}orientations and the stress distributions are responsible for such a superior conductivity of the Ce-containing alloys.

关键词： Ce addition Grain refinement Texture Conductivity Ultrahigh-purity copper Rare earths

Recent progress of Pt-based oxygen reduction reaction catalysts for proton exchange membrane fuel cells

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Rare Metals 2024年第6期43卷 2444-2468页

作者： Feng Zhan Kun-song Hu Jin-hua Mai Li-Sheng Zhang Zhen-guo Zhang huan He Xin-hua Liu School of Resources Environment and MaterialsGuangxi UniversityNanning530004China School of Transportation Science and Engineering Beihang UniversityBeijing 102206China IDTECH(Suzhou)Co.Ltd Suzhou 215217China Dyson School of Design Engineering Imperial College LondonLondon SW72AZUK

With the increasing consumption of fossil fuels,proton exchange membrane fuel cells(PEMFCs)have attracted considerable attention as green and sustainable energy conversion *** slow kinetics of the cathodic oxygen reduction reaction(ORR)has a major impact on the performance of PEMFCs,and although platinum(Pt)can accelerate the reaction rate of the ORR,the scarcity and high cost of Pt resources still limit the development of ***,the development of low-cost high-performance ORR catalysts is essential for the commercial application and development of *** paper reviews the research progress of researchers on Pt-based ORR catalysts in recent years,including Pt/C catalysts,Pt-based alloy catalysts,Pt-based intermetallic compounds,and Pt-based single-atom catalysts(SACs),with a focus on Pt-based alloy catalysts with different *** described in detail the difficulties and solutions in the research process of various ORR catalysts and explained the principle of their activity enhancement with density functional theory(DFT).In addition,an outlook on the development of Pt-based catalysts is given,and reducing the amount of Pt used and improving the performance of catalysts are the directions to work on in the coming period.

关键词： Pt-based catalysts PEMFCs Pt-based intermetallic compounds Single-atom catalysts

Laser powder bed fusion of NiTiFe shape memory alloy via premixed powder:microstructural evolution,mechanical and functional properties

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Rare Metals 2024年第5期43卷 2300-2316页

作者： Bo Yuan Jin-guo Ge Liang Zhang Hong-Jun Chen Long-Sha Wei Yu-Duo Zhou Run-hua song Institute of Intelligent Manufacturing Technology Shenzhen PolytechnicShenzhen 518055China School of Mechanical and Electrical Engineering Guilin University of Electronic TechnologyGuilin 541004China Guangdong Advanced Polymer Composite Engineering Technology Research Center Shenzhen Academy of Aerospace TechnologyShenzhen 518057China Jihua Laboratory Testing Center Jihua LaboratoryFoshan 528000China

High-cost pre-alloyed powder is the bottleneck problem that limits the widespread application of additivemanufactured shape memory *** this work,the lowcost ternary NiTiFe shape memory alloy is fabricated by laser powder bed fusion(LPBF)technique via mechanically mixed pre-alloy NiTi powder and varying contents pure Fe powder(1,2,3 wt%).All NiTiFe alloys show a relative density of up to 99.8%by optimizing the LPBF processing *** to the heterogeneous nucleation effect of micron-sized Fe particles,both grain refinement and texture weakening are generated in the NiTiFe alloys,accompanied by the reduction of dislocation *** the room-temperature mechanical properties,the NiTi-3Fe alloy shows the highest microhardness of HV370,but the fracture strength and elongation reduce to1701 MPa and 23%*** evolution of mechanical properties is attributed to the high internal defects,low dislocation density and the incoherent ***,the NiTi-3Fe alloy shows the quasi-linear superelasticity behavior;the superelastic recoverable strain of NiTi-1Fe and NiTi-2Fe decreased with the increase in Fe *** study provided a new-fangled insight for the development of multi-component NiTi-based shape memory alloys by additive manufacturing.

关键词： Additive manufacturing Shape memory alloy Metal matrix composite Microstructure Mechanical properties

Electrochemical anodic oxidation assisted fabrication of memristors

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International Journal of Extreme Manufacturing 2024年第3期6卷 250-272页

作者： Shuai-Bin hua Tian Jin Xin guo School of Materials Science and Engineering State Key Laboratory of Material Processing and Die&Mould TechnologyHuazhong University of Science and TechnologyWuhan 430074People’s Republic of China

Owing to the advantages of simple structure,low power consumption and high-density integration,memristors or memristive devices are attracting increasing attention in the fields such as next generation non-volatile memories,neuromorphic computation and data ***,the deposition of memristive films often requires expensive equipment,strict vacuum conditions,high energy consumption,and extended processing *** contrast,electrochemical anodizing can produce metal oxide films quickly(e.g.10 s) under ambient *** means of the anodizing technique,oxide films,oxide nanotubes,nanowires and nanodots can be fabricated to prepare *** film thickness,nanostructures,defect concentrations,etc,can be varied to regulate device performances by adjusting oxidation parameters such as voltage,current and *** memristors fabricated by the anodic oxidation technique can achieve high device consistency,low variation,and ultrahigh yield *** article provides a comprehensive review of the research progress in the field of anodic oxidation assisted fabrication of ***,the principle of anodic oxidation is introduced;then,different types of memristors produced by anodic oxidation and their applications are presented;finally,features and challenges of anodic oxidation for memristor production are elaborated.

关键词： anodic oxidation anodized aluminium oxide memristor resistive switching electrical properties

Vertically aligned montmorillonite aerogel-encapsulated polyethylene glycol with directional heat transfer paths for efficient solar thermal energy harvesting and storage

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International Journal of Minerals,Metallurgy and Materials 2024年第5期31卷 907-916页

作者： Qijing guo Cong guo Hao Yi Feifei Jia Shaoxian song Key Laboratory of Green Utilization of Critical Non-metallic Mineral Resources Ministry of EducationWuhan University of TechnologyWuhan 430070China School of Resources and Environmental Engineering Wuhan University of TechnologyWuhan 430070China Hubei Key Laboratory of Mineral Resources Processing and Environment Wuhan University of TechnologyWuhan 430070China

The conversion and storage of photothermal energy using phase change materials(PCMs)represent an optimal approach for harnessing clean and sustainable solar ***,we encapsulated polyethylene glycol(PEG)in montmorillonite aerogels(3D-Mt)through vacuum impregnation to prepare 3D-Mt/PEG composite *** used as a support matrix,3D-Mt can effectively prevent PEG leakage and act as a flame-retardant barrier to reduce the flammability of ***,3D-Mt/PEG demonstrates outstanding shape retention,increased thermal energy storage density,and commendable thermal and chemical *** phase transition enthalpy of 3D-Mt/PEG can reach 167.53 J/g and remains stable even after 50 heating-cooling ***,the vertical sheet-like structure of 3D-Mt establishes directional heat transport channels,facilitating efficient phonon *** configuration results in highly anisotropic thermal conductivities that ensure swift thermal responses and efficient heat *** study addresses the shortcomings of PCMs,including the issues of leakage and inadequate flame *** achieves the development and design of 3D-Mt/PEG with ultrahigh strength,superior flame retardancy,and directional heat ***,this work offers a design strategy for the preparation of high-performance composite *** 3D-Mt/PEG with vertically aligned and well-ordered array structure developed in this research shows great potential for thermal management and photothermal conversion applications.

关键词： montmorillonite aerogel polyethylene glycol phase change materials solar thermal energy storage flame retardant

A POLAROGRAPHIC CATALYTIC WAVE OF OXYGEN INDUCED BY DIPHENYLAMINE COMPOUNDS

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Chinese Chemical Letters 1992年第1期3卷 67-68页

作者： Jun Feng song Wei guo Yin hua HU Department of Chemistry,Northwest University,Xi’an 710069

It is reported in this paper a polarographic catalytic double wave of oxygen reduction caused by diphenylamine compounds(diphs).The electrochemical process of the wave includes the polarographic generation of the supe... 详细信息

关键词： A POLAROGRAPHIC CATALYTIC WAVE OF OXYGEN INDUCED BY DIPHENYLAMINE COMPOUNDS