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A three-dimensional two-level gradient smoothing meshfree method for rainfall induced landslide simulations

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Frontiers of Structural and Civil Engineering 2019年第2期13卷 337-352页

作者： Dongdong WANG Jiarui WANG Junchao WU junjun deng Ming SUN Department of Civil Engineering and Xiamen Engineering Technology Center far Intelligent Maintenance of Infrastructures Xiamen UniversityXiamen 361005China Fujian Provincial Key Laboratory of Mathematical Modeling and High-Performance Scientific Computation Xiamen University Xiamen 361005China

A three-dimensional two-level gradient smoothing meshfree method is presented for rainfall induced landslide simulations. The two-level gradient smoothing for meshfree shape function is elaborated in the threedimensional Lagrangian setting with detailed implementation procedure. It is shown that due to the successive gradient smoothing operation without the requirement of derivative computation in the present formulation, the two-level smoothed gradient of meshfree shape function is capable of achieving a given influence domain more efficiently than the standard gradient of meshfree shape function. Subsequently, the two-level smoothed gradient of meshfree shape function is employed to discretize the weak form of coupled rainfall seepage and soil motion equations in a nodal integration format, as provides an efficient three-dimensional regularized meshfree formulation for large deformation rainfall induced landslide simulations. The exponential damage and pressure dependent plasticity relationships are utilized to describe the failure evolution in landslides. The plastic response of soil is characterized by the true effective stress measure, which is updated according to the rotationally neutralized objective integration algorithm. The effectiveness of the present threedimensional two?level gradient smoothing meshfree method is demonstrated through numerical examples.

关键词： meshfree method landslide rainfall three-dimensional two-level gradient smoothing nodal integration

Chassis Coordinated Control for Full X-by-Wire Vehicles-A Review

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Chinese Journal of Mechanical Engineering 2021年第2期34卷 1-25页

作者： Lei Zhang Zhiqiang Zhang Zhenpo Wang junjun deng David G.Dorrell National Engineering Laboratory for Electric Vehicles Beijing Institute of TechnologyBeijing 100081China Collaborative Innovation Center for Electric Vehicles in Beijing Beijing Institute of TechnologyBeijing 100081China School of Electrical and Information Engineering University of the WitwatersrandJohannesburgSouth Africa

An X-by-wire chassis can improve the kinematic characteristics of human-vehicle closed-loop system and thus active safety especially under emergency scenarios via enabling chassis coordinated *** paper aims to provide a complete and systematic survey on chassis coordinated control methods for full X-by-wire vehicles,with the primary goal of summarizing recent reserch advancements and stimulating innovative *** condition identification including driver’s operation intention,critical vehicle states and road adhesion condition and integrated control of X-by-wire chassis subsystems constitute the main framework of a chassis coordinated control *** steering and braking maneuvers,different driving condition identification methods are described in this *** are the trigger conditions and the basis for the implementation of chassis coordinated *** the vehicles equipped with steering-by-wire,braking-by-wire and/or wire-controlled-suspension systems,state-of-the-art chassis coordinated control methods are reviewed including the coordination of any two or three chassis ***,the development trends are discussed.

关键词： X-by-wire systems Chassis coordinated control Driving condition identification Active safety

Magnetic Coupler Robust Optimization Design for Electric Vehicle Wireless Charger Based on Improved Simulated Annealing Algorithm

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Automotive Innovation 2022年第1期5卷 29-42页

作者： Zhenpo Wang Lantian Li junjun deng Baokun Zhang Shuo Wang School of Mechanical Engineering Beijing Institute of TechnologyNO.5 Zhongguancun StreetBeijingChina Collaborative Innovation Center of Electric Vehicles in Beijing NO.5 Zhongguancun StreetBeijingChina

Fleets of autonomous vehicles including shuttle buses,freight trucks,and road sweepers will be deployed in the Olympic Vil-lage during Beijing 2022 Winter *** requires intelligent charging infrastructure based on wireless power transfer technology to be *** increase the misalignment tolerance of a high-power wireless charger,the robustness of the magnetic coupler should be *** paper presents a new type of unipolar coupler,which is composed of three con-nected coils in *** dimensional configuration of the coils is analyzed by the finite element *** characteristic parameters of the coil are identified with their influence on the self-inductance and coupling *** expert model is built,whose feasibility can be verified in the aimed design *** with the expert model,an improved simulated annealing algorithm with a backtracking mechanism is *** primary coil can reach the expected characteristics from any starting parameter combination through the proposed optimization *** the same conditions in terms of external circuit parameters,ferrite usage,and aluminum shielding,the offset sensitivity of the magnetic coupler can be reduced from 58.79%to 18.89%.A prototype is established,validating the feasibility of the proposed coil structure with the optimized parameter algorithm.

关键词： Wireless power transfer Magnetic coupler Simulated annealing algorithm Robust optimization

Aerosol light absorption in a coastal city in Southeast China:Temporal variations and implications for brown carbon

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Journal of Environmental Sciences 2019年第6期31卷 257-266页

作者： Yuqing Qiu Xin Wu Yanru Zhang Lingling Xu Youwei Hong Jinsheng Chen Xiaoqiu Chen junjun deng Center for Excellence in Regional Atmospheric Environment Institute of Urban Environment Chinese Academy of Sciences Key Laboratory of Urban Environment and Health Institute of Urban Environment Chinese Academy of Sciences University of Chinese Academy of Sciences Fujian Environmental Monitoring Station Institute of Surface-Earth System Science Tianjin University

Light-absorbing carbonaceous aerosols including black carbon(BC) and brown carbon(BrC)play significant roles in atmospheric radiative properties. One-year measurements of aerosol light absorption at multi-wavelength were continuously conducted in Xiamen,southeast of China in 2014 to determine the light absorption properties including absorption coefficients(σabs) and absorption ?ngstr?m exponent(AAE) in the coastal *** absorptions of BC and BrC with their contributions to total light absorption were further quantified. Mean σabsat 370 nm and 880 nm were 56.6 ± 34.3 and 16.5 ± 11.2 Mm-1,respectively. σabspresented a double-peaks diurnal pattern with the maximum in the morning and the minimum in the afternoon. σabswas low in warm seasons and high in cold seasons. AAE ranged from 0.26 to 2.58 with the annual mean of 1.46, implying that both fossil fuel combustion and biomass burning influenced aerosol optical properties. σabsof BrC at 370 nm was 24.0 ± 5.7 Mm-1, contributing 42% to the total absorption. The highest AAE(1.52 ± 0.02) and largest BrC contributions(47% ± 4%) in winter suggested the significant influence of biomass burning on aerosol light absorption. Long-distance air masses passing through North China Plain and the Yangtze River Delta led to high AAE and BrC contributions. High AAE value of 1.46 in July indicated that long-range transport of the air pollutants from intense biomass burning in Southeast Asia would affect aerosol light absorption in Southeast China. The study will improve the understanding of light absorption properties of aerosols and the optical impacts of BrC in China.

关键词： Light absorption Brown carbon Black carbon Absorption Angstrom exponent Biomass burning Western Taiwan Strait

Chemical characterization and source apportionment of atmospheric submicron particles on the western coast of Taiwan Strait, China

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Journal of Environmental Sciences 2017年第2期29卷 293-304页

作者： Liming Cao Qiao Zhu Xiaofeng Huang junjun deng Jinsheng Chen Youwei Hong Lingling Xu Lingyan He Key Laboratory for Urban Habitat Environmental Science and Technology School of Environment and Energy Peking University Shenzhen Graduate School Center for Excellence in Urban Atmospheric Environment Institute of Urban Environment Chinese Academy of Sciences

Taiwan Strait is a special channel for subtropical East Asian Monsoon and its western coast is an important economic zone in China. In this study, a suburban site in the city of Xiamen on the western coast of Taiwan Strait was selected for fine aerosol study to improve the understanding of air pollution sources in this region. An Aerodyne high-resolution time-of-flight aerosol mass spectrometer（HR-To F-AMS） and an Aethalometer were deployed to measure fine aerosol composition with a time resolution of 5 min from May 1to 18, 2015. The average mass concentration of PM1 was 46.2 ± 26.3 μg/m^3 for the entire campaign. Organics（28.3%）, sulfate（24.9%）, and nitrate（20.6%） were the major components in the fine particles, followed by ammonium, black carbon（BC）, and chloride. Evolution of nitrate concentration and size distribution indicated that local NOx emissions played a key role in high fine particle pollution in Xiamen. In addition, organic nitrate was found to account for 9.0%–13.8% of the total measured nitrate. Positive Matrix Factorization（PMF）conducted with high-resolution organic mass spectra dataset differentiated the organic aerosol into three components, including a hydrocarbon-like organic aerosol（HOA） and two oxygenated organic aerosols（SV-OOA and LV-OOA）, which on average accounted for 27.6%,28.8%, and 43.6% of the total organic mass, respectively. The relationship between the mass concentration of submicron particle species and wind further confirmed that all major fine particle species were influenced by both strong local emissions in the southeastern area of Xiamen and regional transport through the Taiwan Strait.

关键词： Submicron particle Chemical characterization Organic aerosol Source apportionment

China's battery electric vehicles lead the world:achievements in technology system architecture and technological breakthroughs

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Green Energy and Intelligent Transportation 2022年第1期1卷 2-25页

作者： Hongwen He Fengchun Sun Zhenpo Wang Cheng Lin Chengning Zhang Rui Xiong junjun deng Xiaoqing Zhu Peng Xie Shuo Zhang Zhongbao Wei Wanke Cao Li Zhai National Engineering Research Centre of Electric Vehicles Beijing Institute of TechnologyBeijing100081PR China

Developing new energy vehicles has been a worldwide consensus,and developing new energy vehicles characterized by pure electric drive has been China's national *** more than 20 years of high-quality development of China's electric vehicles(EVs),a technological R&D layout of“Three Verticals and Three Horizontals”has been created,and technological advantages have been *** a result,China's new energy vehicle market has ranked first in the world since *** systematically solve the key problems of battery electric vehicles(BEVs)such as“driving range anxiety,long battery charging time,and driving safety hazards”,China took the lead in putting forward a“system engineering-based technology system architecture for BEVs”and clarifying its *** paper analyzes the research status and progress of the three core components of this architecture,namely,“BEV platform,charging/swapping station,and real-time operation monitoring platform”,and their key technological *** three major demonstration projects of the 2008 Beijing Olympic Games,the 2022 Beijing Winter Olympics,and the intelligent and connected autonomous battery electric bus project are discussed to specify the applications of BEVs in *** key research directions for upgrading BEV technologies remain to be further improving the vehicle-level all-climate environmental adaptability and all-day safety of BEVs,systematically solving the charging problem of BEVs and improving their application convenience,and safeguarding safety with early warning and implementing active/passive safety protection for the whole life cycle of power batteries on the basis of BEVs'operation big *** have acquired new technological features such as intelligent and networked technology empowerment,extensive integration of control-by-wire systems,a platform of chassis hardware,and modularization of functional software.

关键词： Battery electric vehicle(BEV) Charging/swapping station Operation monitoring platform Technology system Motor drive system All-climate Battery Battery safety China

Fluorescence Properties and Chemical Composition of Fine Particles in the Background Atmosphere of North China

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Advances in Atmospheric Sciences 2023年第7期40卷 1159-1174页

作者： Ping LI Siyao YUE Xiaoyang YANG Di LIU Qiang ZHANG Wei HU Shengjie HOU Wanyu ZHAO Hong REN Gang LI Yuanguan GAO junjun deng Qiaorong XIE Yele SUN Zifa WANG Pingqing FU State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China State Key Laboratory of Environmental Criteria and Risk Assessment Chinese Research Academy of Environmental SciencesBeijing 100012China Institute of Surface-Earth System Science School of Earth System ScienceTianjin UniversityTianjin 300072China University of Chinese Academy of Sciences Beijing 100049China

To understand the aerosol characteristics in a regional background environment,fine-particle(PM_(2.5),n=228)samples were collected over a one-year period at the Shangdianzi(SDZ)station,which is a Global Atmospheric Watch regional background station in North *** chemical and optical characteristics of PM_(2.5)were analyzed,including organic carbon,elemental carbon,water-soluble organic carbon,water-soluble inorganic ions,and fluorescent components of watersoluble organic *** source factors of major aerosol components are apportioned,and the sources of the fluorescent chromophores are further *** major chemical components of PM_(2.5)at SDZ were NO_(3)^(-),organic matter,SO_(4)^(2-),and NH_(4)^(+).Annually,water-soluble organic carbon contributed 48%±15%to the total organic *** formation(52%)and fossil fuel combustion(63%)are the largest sources of water-soluble organic matter and water-insoluble organic matter,*** addition,three humic-like and one protein-like matter were identified via parallel factor analysis for excitation–emission *** fluorescence intensities of the components were highest in winter and lowest in summer,indicating the main impact of burning *** study contributes to understanding the chemical and optical characteristics of ambient aerosols in the background atmosphere.

关键词： fine aerosols excitation-emission matrix fluorescence properties primary biological aerosols Shangdianzi

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基于卷积神经网络的逆变器故障诊断方法

汽车工程 2022年第1期44卷 142-151页

作者：于海邓钧君王震坡孙逢春北京理工大学电动车辆国家工程实验室北京100081 北京电动车辆协同创新中心北京100081

针对车用永磁同步电机驱动系统在长期运行过程中存在的逆变器故障风险,本文中提出了一种基于卷积神经网络的逆变器故障诊断方法。首先,对三相定子电流数据进行标幺化和单位电周期电流数据筛选处理,降低电机驱动系统变转矩、变转速工况... 详细信息

针对车用永磁同步电机驱动系统在长期运行过程中存在的逆变器故障风险,本文中提出了一种基于卷积神经网络的逆变器故障诊断方法。首先,对三相定子电流数据进行标幺化和单位电周期电流数据筛选处理,降低电机驱动系统变转矩、变转速工况对故障诊断效果的影响;然后,结合卷积神经网络,发挥其提取故障特征和抗噪优势,实现逆变器故障诊断。在MATLAB/Simulink环境中搭建了车用永磁同步电机驱动系统模型,通过故障注入仿真数据和实验数据构建用于卷积神经网络训练的数据集,验证了所提出故障诊断方法的有效性。同时,探究了训练样本数据集稀疏化和电机型号差异化情况的适用性。仿真结果表明:在噪声数据和稀疏数据条件下,本文中提出的故障诊断方法具有很好的鲁棒性和普适性。

关键词：逆变器三相定子电流卷积神经网络故障诊断

A Modeling Study On Heterogeneous Chemical Processes On Aerosol Surface

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A Modeling Study On Heterogeneous Chemical Processes On Aero...