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Flow-induced vibrations of long circular cylinders modeled by coupled nonlinear oscillators

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Science China(Physics,Mechanics & Astronomy) 2009年第7期52卷 1086-1093页

作者： GE fei long Xu wang Lei HONG YouShi State Key Laboratory of Nonlinear Mechanics Institute of MechanicsChinese Academy of SciencesBeijing 100190China

The dynamics of long slender cylinders undergoing vortex-induced vibrations (VIV) is studied in this work. long slender cylinders such as risers or tension legs are widely used in the field of ocean engineering. When the sea current flows past a cylinder, it will be excited due to vortex shedding. A three-dimensional time domain model is formulated to describe the response of the cylinder, in which the in-line (IL) and cross-flow (CF) deflections are coupled. The wake dynamics, including in-line and cross-flow vibrations, is represented using a pair of non-linear oscillators distributed along the cylinder. The wake oscillators are coupled to the dynamics of the long cylinder with the acceleration coupling term. A non-linear fluid force model is accounted for to reflect the relative motion of cylinder to current. The model is validated against the published data from a tank experiment with the free span riser. The comparisons show that some aspects due to VIV of long flexible cylinders can be reproduced by the proposed model, such as vibrating frequency, dominant mode number, occurrence and transition of the standing or traveling waves. In the case study, the simulations show that the IL curvature is not smaller than CF curvature, which indicates that both IL and CF vibrations are important for the structural fatigue damage.

关键词： vortex-induced vibration (VIV) vortex-induced wave (VIW) wake oscillator long cylinder fluid-structure interaction

An improved three-dimensional spherical DDA model for simulating rock failure

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Science China(Technological Sciences) 2015年第9期58卷 1533-1541页

作者： JIAO YuYong HUANG GangHai ZHAO ZhiYe ZHENG fei wang long State Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil Mechanics Chinese Academy of Sciences School of Civil and Environmental Engineering Nanyang Technological University

In this paper, a discontinuous numerical model, namely SDDARF3D(three-dimensional spherical discontinuous deformation analysis for rock failure), is proposed for simulating the whole process of rock failure. Firstly, within the framework of the classical discontinuous deformation analysis(DDA) method, the formulation of three-dimensional spherical DDA(3D SDDA) is deduced; secondly, a bonding and cracking algorithm is constructed and the SDDARF3 D model is proposed; thirdly, corresponding VC++ calculation code is developed and some verification examples are calculated. The simulated results can intuitively reproduce the failure phenomena of rock mass, indicating that the proposed SDDARF3 D numerical model is correct and effective.

关键词： rock failure three-dimensional spherical discontinuous deformation analysis crack propagation bonding and cracking algorithm

Biocompatibility of marine magnetotactic ovoid strain MO-1 for in vivo application

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Journal of Oceanology and Limnology 2021年第6期39卷 2107-2115页

作者： Changyou CHEN Pingping wang long-fei WU Tao SONG Beijing Key Laboratory of Bioelectromagnetism Institute of Electrical EngineeringChinese Academy of SciencesBeijing 100190China France-China Joint Laboratory for Evolution and Development of Magnetotactic Multicellular Organisms Chinese Academy of SciencesBeijing 100029China Aix Marseille University CNRSLCBMarseille F-13402France University of the Chinese Academy of Sciences Beijing 100049China

Magnetotactic bacteria are capable of biosynthesizing magnetic nanoparticles,also called magnetosomes,and swimming along magnetic field *** abilities endow the whole cells of magnetotactic bacteria with such applications as targeted therapy and manipulation of *** have shown that the intact marine magnetotactic bacteria MO-1 kill efficiently antibiotic-resistant pathogen Staphylococcus aureus in vivo,but the biocompatibility of this marine bacterium is *** this study,the strain MO-1 was chosen to analyze its biocompatibility and potential for biomedicine *** showed that MO-1 cells could be guided at 37℃ under an external magnetic field and swim in the blood plasma and *** could keep active locomotivity within 40 min in the plasma and urine,although their velocity slowed *** incubated with human cells,magnetotactic bacteria MO-1 had no obvious effects on cellular viability at low dose,while the cell toxicity increased with the augmentation of the quantity of the MO-1 cells *** the in-vivo experiments,the median lethal dose of magnetotactic bacteria MO-1 in rats was determined to be 7.9×10^(10) bacteria/*** results provided the foundation for the biocompatibility and safety evaluations of magnetotactic bacteria MO-1 and suggested that they could be basically used in clinical targeted therapy.

关键词： magnetotactic bacteria motility cell interaction median lethal dose

Control of topological phase transitions in Dirac semimetal films by exchange fields

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Chinese Physics B 2017年第1期26卷 386-390页

作者： fei Yang Hai-long wang Hui Pan Department of Physics Beihang University Belting 100191 China

The exchange field effects on topological Dirac semimetal（DSM） films are discussed in this article. A topological phase transition can be controlled by tuning the exchange field together with the quantum confinement effects. What is more interesting is that the system can transit into the quantum anomalous Hall（QAH） state from the topologically trivial state（Z2 = 0） or from the topologically nontrivial state（Z2 = 1）, depending on the thickness of the DSM films. This provides a useful mechanism to realize the QAH state from the DSM.

关键词： exchange field Dirac semimetal quantum anomalous Hall state quantum spin Hall state

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风力发电机液压变桨系统设计

液压气动与密封 2019年第10期39卷 58-59页

作者：费望龙龚佳兴杨岱璋刘洁长沙中金智能装备股份有限公司

采用数学解析法推导出变桨驱动力矩M是与液压缸活塞承压面积A、变桨机构回转半径r、中心距a、液压缸安装距L min四重自变量以及桨距角θ有关的函数,结合变桨载荷对变桨机构进行优化设计,并对关键零部件进行强度分析。

关键词：风力发电机液压变桨液压缸

Ti_(3)C_(2)T_(x)-TiSe_(2) analogous heterostructure for flexible zinc ion battery

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Journal of Materials Science & Technology 2023年第19期150卷 225-232页

作者： Li Wen Junjie Shi Qixiang Zhang fei wang Siliang wang Shaojun Zhang Qiang wang Ke Mao fei long Yihua Gao Center for Nanoscale Characterization&Devices(CNCD) School of Physics and Wuhan National Laboratory for Optoelectronics(WNLO)Huazhong University of Science and Technology(HUST)Wuhan 430074China Information Materials and Intelligent Sensing Laboratory of Anhui Province School of Integrated CircuitsAnhui UniversityHefei 230601China College of Materials Science and Engineering Guangxi Key Laboratory of Optical and Electronic Materials and DevicesGuilin University of TechnologyGuilin 541004China

Exploring zinc-free anode materials is one of the effective strategies to get the zinc dendrites problem of flexible zinc ion battery(ZIB)*** this work,an analogous heterostructure(AHS)is constructed from the excellent MXene(Ti_(3)C_(2)T_(x))and TiSe_(2) *** AHS not only possesses numerous diffu-sion paths and Zn^(2+)storage sites but also possesses a stable conductive network to accelerate charge transfer in the *** a collaborative advantage,electrochemical measurement results show that MXene/TiSe_(2) electrodes display an excellent specific capacity of 177.9 mAh g^(-1) at 0.10 A g^(-1) and a long-term cycling stability of 77.4%capacity retention after 400 *** computations further demon-strate the excellent performance of MXene/TiSe_(2) electrodes including desirable electronic conductivity and low Zn^(2+)migration *** assembled flexible ZIB not only delivers a good specific capacity of 42.2μAh cm^(-2) at 0.20 mA cm^(-2) and a competitive energy density of 37.4μWh cm^(-2) but also exhibits excellent flexibility and ***,after 400 cycles at 0.60 A g^(-1),flexible ZIB shows a capacity retention of 73.8%.This work gives a successful attempt to design 2D layered materials as Zn metal-free anode for flexible ZIB.

关键词： Flexible zinc ion battery Analogous heterostructure Zinc dendrite Zinc free metal anode MXene flakes TiSe_(2)nanosheets

Parallel Planning:A New Motion Planning Framework for Autonomous Driving

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IEEE/CAA Journal of Automatica Sinica 2019年第1期6卷 236-246页

作者： long Chen Xuemin Hu Wei Tian Hong wang Dongpu Cao fei-Yue wang IEEE School of Data and Computer Science Sun Yat-sen University the School of Computer Science and Information Engineering Hubei University Institute of Measurement and Control Systems Karlsruhe Institute of Technology Department of Mechanical and Mechatronics Engineering University of Waterloo the State Key Laboratory of Management and Control for Complex Systems.Institute of Automation Chinese Academy of Sciences the Research Center for Military Computational Experiments and Parallel Systems Technology National University of Defense Technology

Motion planning is one of the most significant technologies for autonomous driving. To make motion planning models able to learn from the environment and to deal with emergency situations, a new motion planning framework called as"parallel planning" is proposed in this paper. In order to generate sufficient and various training samples, artificial traffic scenes are firstly constructed based on the knowledge from the reality.A deep planning model which combines a convolutional neural network(CNN) with the long Short-Term Memory module(LSTM) is developed to make planning decisions in an end-toend mode. This model can learn from both real and artificial traffic scenes and imitate the driving style of human ***, a parallel deep reinforcement learning approach is also presented to improve the robustness of planning model and reduce the error rate. To handle emergency situations, a hybrid generative model including a variational auto-encoder(VAE) and a generative adversarial network(GAN) is utilized to learn from virtual emergencies generated in artificial traffic scenes. While an autonomous vehicle is moving, the hybrid generative model generates multiple video clips in parallel, which correspond to different potential emergency scenarios. Simultaneously, the deep planning model makes planning decisions for both virtual and current real scenes. The final planning decision is determined by analysis of real observations. Leveraging the parallel planning approach, the planner is able to make rational decisions without heavy calculation burden when an emergency occurs.

关键词： Autonomous driving artificial traffic scene deep learning emergencies motion planning parallel planning

Electro-deoxidation of V_2O_3 in molten CaCl_2-NaCl-CaO

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International Journal of Minerals,Metallurgy and Materials 2012年第3期19卷 212-216页

作者： Shu-lan wang Shi-chao Li long-fei Wan Chuan-hua wang School of Science Northeastern UniversityShenyang 110004China

The electro-deoxidation of V2O3 precursors was studied. Experiments were carried out with a two-terminal electrochemical cell, which was comprised of a molten electrolyte of CaCl2 and NaC1 with additions of CaO, a cathode of compact V2O3, and a graphite anode under the potential of 3.0 V at 1173 K. The phase constitution and composition as well as the morphology of the samples were studied by X-ray diffraction （XRD） and scanning electron microscopy （SEM）. 3 g of V2O3 could be converted to vanadium metal powder within the processing time of 8 h. The kinetic pathway was investigated by analyzing the product phase in samples prepared at different reduction stages. CaO added in the reduction path of V2O3 formed the intermediate product CaV2O4.

关键词： vanadous oxide electro-deoxidation vanadium molten salt electrochemical cells

Role of iron ore in enhancing gasification of iron coke:Structural evolution,influence mechanism and kinetic analysis

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International Journal of Minerals,Metallurgy and Materials 2025年第1期32卷 58-69页

作者： Jie wang Wei wang Xuheng Chen Junfang Bao Qiuyue Hao Heng Zheng Runsheng Xu School of Chemistry and Materials Science Hubei Engineering UniversityXiaogan 432000China Key Laboratory for Ferrous Metallurgy and Resources Utilization of Ministry of Education Wuhan University of Science and TechnologyWuhan 430081China Institue of Ironmaking Technology Baosteel Central Research InstituteShanghai 201999China State Key Laboratory of Advanced Metallurgy University of Science and Technology BeijingBeijing 100083China

The utilization of iron coke provides a green pathway for low-carbon *** uncover the influence mechanism of iron ore on the behavior and kinetics of iron coke gasification,the effect of iron ore on the microstructure of iron coke was ***,a comparative study of the gasification reactions between iron coke and coke was conducted through non-isothermal thermogravimetric *** findings indicate that compared to coke,iron coke exhibits an augmentation in micropores and specific surface area,and the micropores further extend and *** provides more adsorption sites for CO_(2) molecules during the gasification process,resulting in a reduction in the initial gasification temperature of iron *** the heating rate in non-isothermal gasification can enhance the reactivity of iron *** metallic iron reduced from iron ore is embedded in the carbon matrix,reducing the orderliness of the carbon structure,which is primarily responsible for the heightened reactivity of the carbon *** kinetic study indicates that the random pore model can effectively represent the gasification process of iron coke due to its rich pore ***,as the proportion of iron ore increases,the activation energy for the carbon gasification gradually decreases,from 246.2 kJ/mol for coke to 192.5 kJ/mol for iron coke 15wt%.

关键词： low-carbon ironmaking iron coke gasification structural evolution kinetic model