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农用运输车步入买方市场
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作者 高辉清 《中国商贸》 1999年第2期19-20,共2页
我国农用运输车,从1979年起步至今,已走过3个阶段,特别是1987年至1995年是其高速发展阶段,产品已覆盖我国大部分地区,1993年被列入机械部与公安部目录的生产企业就达200多家,1995年达到年产230万辆.1996年以后进入平稳发展阶段,产量增... 我国农用运输车,从1979年起步至今,已走过3个阶段,特别是1987年至1995年是其高速发展阶段,产品已覆盖我国大部分地区,1993年被列入机械部与公安部目录的生产企业就达200多家,1995年达到年产230万辆.1996年以后进入平稳发展阶段,产量增幅回落,市场饱和,部分地区开始萎缩.当前,农用运输车已步入买方市场. 展开更多
关键词 三轮农用运输车 三轮农用车 车步 行业集中度 农用车企业 生产企业 兼并重组 购车意向 内部职工股 部分地区
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车步单元地质特征及时代初探
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作者 吴旭玲 欧阳克贵 《华东地质学院学报》 2000年第2期121-123,共3页
车步单元为基性侵入体 ,由于钛铁矿含量较高 ,发现有多处矿点 ,与成矿密切相关 ,在岩石化学特征及成岩时代上与区域菖蒲组玄武岩有同期同源性。定位时代为早侏罗世。
关键词 早侏罗世 车步单元 基性侵入体 侵位年代 成矿作用
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有感于下车步行
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作者 李学乾 《中州统战》 1996年第12期23-23,共1页
有感于下车步行前不久回了一趟老家,乡邻向我述说了这样一件事:村人XX,省城官员,回乡省亲,辄于村口二里之外下车步行,让高级轿车远离身后,路遇村人皆敬烟问候,关系甚密。而村人XX,县城某局副科,坐绿色吉普人村后横冲直撞... 有感于下车步行前不久回了一趟老家,乡邻向我述说了这样一件事:村人XX,省城官员,回乡省亲,辄于村口二里之外下车步行,让高级轿车远离身后,路遇村人皆敬烟问候,关系甚密。而村人XX,县城某局副科,坐绿色吉普人村后横冲直撞,村人皆远而避之……其实,官职无论... 展开更多
关键词 车步 密切联系群众 国民党将领 毛泽东 党员干部 与民同乐 端正党风 人民的利益 伏牛山 工作作风
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一支特殊的步兵——瑞士自行车步兵
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作者 张红敏 《轻兵器》 北大核心 1995年第3期23-23,共1页
瑞士地处欧洲中部,国土面积狭小,且多为山地,境内森林密布。自1815年奉行永久武装中立政策。根据其军事防御战略和国内地形特点,瑞士于1891年组建了自行车步兵部队(以下简称自步兵)。一百多年来自步兵在瑞士国防中发挥了应有的重要作用... 瑞士地处欧洲中部,国土面积狭小,且多为山地,境内森林密布。自1815年奉行永久武装中立政策。根据其军事防御战略和国内地形特点,瑞士于1891年组建了自行车步兵部队(以下简称自步兵)。一百多年来自步兵在瑞士国防中发挥了应有的重要作用,至今仍为瑞士军方所重视,甚至引起军事大国如美国的兴趣。现将外刊介绍的情况编译整理如下: 展开更多
关键词 步兵部队 瑞士 车步 基础训练 武装中立 机械化步兵 机械化部队 反坦克 空中突击 特有价值
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2003年第9期有奖征答答案
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《棋艺(象棋)》 2003年第11期62-62,共1页
关键词 2003年 测验题 特级大师 大读者 第三季度 车步 本象 期刊 炮车 棋友
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排局乐园
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《棋艺(象棋)》 2002年第9期50-51,共2页
关键词 四平 如下所述 车步 五马
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Humanoid Robot 3-D Motion Simulation for Hardware Realization
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作者 曹曦 赵群飞 马培荪 《Journal of Donghua University(English Edition)》 EI CAS 2007年第6期713-717,722,共6页
In this paper,three dimensions kinematics and kinetics simulation are discussed for hardware realization of a physical biped walking-chair robot.The direct and inverse close-form kinematics solution of the biped walki... In this paper,three dimensions kinematics and kinetics simulation are discussed for hardware realization of a physical biped walking-chair robot.The direct and inverse close-form kinematics solution of the biped walking-chair robot is deduced.Several gaits are realized with the kinematics solution,including walking straight on level floor,going up stair,squatting down and standing up.Zero Moment Point(ZMP)equation is analyzed considering the movement of the crew.The simulated biped walking-chair robot is used for mechanical design,gaits development and validation before they are tested on real robot. 展开更多
关键词 Humanoid robot walking chair robot gait design 3D simulation ZMP
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UAQ4 Magnetic Levitating Train: Propulsion System for Urban Transportation
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作者 Gino D'Ovidio Francesco Crisi 《Journal of Energy and Power Engineering》 2012年第12期1952-1956,共5页
This paper discusses the design of the propulsion system of the UAQ4 (University of L'Aquila, model 4) magnetic levitating train which is used for transportation applications in urban environments. UAQ4 is the only... This paper discusses the design of the propulsion system of the UAQ4 (University of L'Aquila, model 4) magnetic levitating train which is used for transportation applications in urban environments. UAQ4 is the only magnetic levitating vehicle with resistance motion, except for aerodynamic drag and with energy consumption near zero at low speed. The feasibility of the system has been successfully verified and tested in the laboratory. Propulsion and braking are provided by a novel direct-current linear stepper motor, with the primary formed by permanent magnets distributed on central beam of the track, and the secondary by coils on board the vehicle, instead of the present alternate current linear motors that have well-known disadvantages. The motor working principles are described, and its performances are analyzed, by a finite element numerical model which allows modifying the most important parameters of the system. The main components of a full scale motor for urban transportation are measured and discussed. 展开更多
关键词 Linear motor PROPULSION magnetically levitating train transportation system energy consumption.
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Design of relative position sensing system for high-speed maglev train
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作者 钱存元 Han Zhengzhi +1 位作者 Xie Weida Shao Derong 《High Technology Letters》 EI CAS 2008年第1期18-23,共6页
In the high-speed maglev system,accurate real-time information of the train position is essential forstable,safe and efficient train operation.To detect the relative position of the high-speed maglev trainfrom a refer... In the high-speed maglev system,accurate real-time information of the train position is essential forstable,safe and efficient train operation.To detect the relative position of the high-speed maglev trainfrom a reference position,a location method based on long stator slot detection was proposed.Besides,aprototype system has been successfully developed.The hardware structure of the system,as well as itsworking principle was described.Moreover,a subdivision algorithm for calculating the pole location anglesignal was elucidated.Experiments show that the proposed method is feasible.The technical indexes ofthe detection system satisfy the requirements of the vehicle operation control system.The relative positionsensing system can be put into practice. 展开更多
关键词 MAGLEV relative position linear synchronous motor SUBDIVISION
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A novel license plate recognition method using HTD and VTD features 被引量:2
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作者 Zhang Xiangdong Shen Peiyi Li Liangchao Wang Wei Bai Jianhua Zhang Wenbo 《Engineering Sciences》 EI 2010年第1期71-76,共6页
In this paper, a novel method of licence plate recognition (LPR) using the vertical traverse density (VTD) and horizontal traverse density (HTD) is presented. The neutral network algorithm using VTD and HTD features i... In this paper, a novel method of licence plate recognition (LPR) using the vertical traverse density (VTD) and horizontal traverse density (HTD) is presented. The neutral network algorithm using VTD and HTD features is also an innovation. In addition, a so called secondary recognition method which splits characters into different parts is developed. Experimental results show that it is a simple and fast algorithm, which meets the request of real time and nicety performances of LPR and thus has applied value in intelligence transportation system (ITS). 展开更多
关键词 license plate recognition character segment character recognition VTD and HTD features
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The New Brazilian Automotive Policy Challenges in the Technological Advancement of Vehicle Security in Brazil
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作者 Erik Telles Pascoal Antonio Lopes Nogueira da Silva Valter Silva Ferreira Filho 《Journal of Mechanics Engineering and Automation》 2015年第5期291-296,共6页
With almost 23% of the industry's GDP (gross domestic public), the Brazilian automobile industry confirms, once more, to be one of the most important sectors for national economy in the past years. Due to this rele... With almost 23% of the industry's GDP (gross domestic public), the Brazilian automobile industry confirms, once more, to be one of the most important sectors for national economy in the past years. Due to this relevance, in October 2012, the Brazilian government has approved by decree a program of incentive to innovation and intensification of the local productive chain in the automotive industry called "Inovar-Auto". The new Brazilian automotive policy aims by encouraging R & D (research and development) to raise the technological level of vehicles manufactured in country. Undoubtedly, those initiatives contribute hugely for inserting the country on worldwide route of technological development encouraging the local production of safer vehicles and better technological contents. The search for this standard of vehicles has been a subject of several studies in the automotive world and in recent years it has gained importance, including being one of the Inovar-Auto challenges. In this context, this paper aims to present, through a theoretical research, key technologies and vehicle security initiatives developed so far in worldwide and to point out the challenges for development in the national market. 展开更多
关键词 Inovar-Auto vehicle security R D.
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Research on Industry Cluster Competitiveness Based on DEA-Ridge Regression Two-step Method--,Taking the Hunan Automobile Industry Cluster as an Example
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作者 Liu Juan 《International Journal of Technology Management》 2014年第9期75-78,共4页
Based on DEA - Ridge Regression two-step method, the paper tries to construct industrial cluster competitiveness research framework for empirical analysis, and by the Hunan automobile industry cluster as an example. T... Based on DEA - Ridge Regression two-step method, the paper tries to construct industrial cluster competitiveness research framework for empirical analysis, and by the Hunan automobile industry cluster as an example. The study found that Hunan automobile industry cluster competitiveness is relatively weak, full of the very big promotion space; further research shows that the human capital investment, fixed capital investment, land investment and policy support are the main factors influencing the efficiency of automobile industry cluster in Hunan province. 展开更多
关键词 Industry cluster competitiveness DEA-Ridge Regression FACTORS
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A Study on the Structure of Linear Synchronous Motor for 600 km/h Very High Speed Train
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作者 Chan-Bae Park Byung-Song Lee 《Journal of Energy and Power Engineering》 2014年第2期374-378,共5页
Recently, an interest in a hybrid system combining only the merits of the conventional wheel-rail system and Maglev propulsion system is growing as an alternative to high-speed maglev train. This hybrid-type system is... Recently, an interest in a hybrid system combining only the merits of the conventional wheel-rail system and Maglev propulsion system is growing as an alternative to high-speed maglev train. This hybrid-type system is based on wheel-rail method, but it enables to overcome the speed limitation by adhesion because it is operated through a non-contact method using a linear motor as a propulsion system and reduce the overall construction costs by its compatibility with the conventional railway systems. Therefore, a comparative analysis on electromagnetic characteristics according to the structural combinations on the stator-mover of LSM (linear synchronous motor) for VHST (very high speed train) maintaining the conventional wheel-rail method is conducted, and the structure of coreless superconducting LSM suitable for 600 km/h VHST is finally proposed in this paper. 展开更多
关键词 Very high speed train linear synchronous motor CORELESS SUPERCONDUCTIVITY wheel-rail.
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Thermal analysis of surface-mounted permanent magnet synchronous motor for electric vehicle application
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作者 范金鑫 Zhang Chengning Wang Zhifu 《High Technology Letters》 EI CAS 2010年第1期80-84,共5页
As a driving motor, surface mounted permanent magnet synchronous motor exhibits high efficiency and high power density. However, it is susceptible to suffer irreversible demagnetization and insulation failure of coils... As a driving motor, surface mounted permanent magnet synchronous motor exhibits high efficiency and high power density. However, it is susceptible to suffer irreversible demagnetization and insulation failure of coils under severe thermal load condition. Therefore, it is essential to predict temperattrre distribution in the driving motor. In this paper, a lumped parameter thermal mode/of surface mounted permanent magnet is investigated. By using finite element method, the iron loss distribution in various parts of the driving motor is achieved. Moreover, the influences of interface gap and flow rate on temperature distribution are discussed. Finally, the simulation of temperature distribution in different parts of the driving motor is achieved. The presented methodology contributes to verify the feasibility of the driving motor design. 展开更多
关键词 thermal analysis lumped-parameter model heat transfer permanent magnet synchronous motor (PMSM) electric vehicle (EV)
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Modern Multilevel Control Technique Used in Electric and Hybrid Drive System with Induction Motors
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作者 Zygmunt Szymanski 《Computer Technology and Application》 2012年第12期789-796,共8页
The mathematical model of the modem induction traction motor (TRIM and cutting magnetic circuit traction motor), supplied with IPM inverter with different control technique is presented in the paper. In electric and... The mathematical model of the modem induction traction motor (TRIM and cutting magnetic circuit traction motor), supplied with IPM inverter with different control technique is presented in the paper. In electric and hybrid vehicle are applied: FLMC (Fuzzy Logic Mode Control), SLMC (Sliding Mode Control), NRMC (Neural Regulator Control), and Direct Power and Torque Control for Space Vector Modulated inverter (DPTC SVM). In the special solution of the electric and hybrid vehicle are also applied a Random Switching Frequency Modulation. The control of hybrid vehicle should assure the realization of established transport-assignments in the definite time, at the optimum of energy consumption. One can this realize using. The multi criteria control system. Some results of the computer simulations are presented in the paper. Results of numerical calculation were verified for laboratory model of the electric and hybrid wheel vehicles traction motor. 展开更多
关键词 Induction motor multilevel control system hybrid drive system random control system.
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A mathematical model of circadian rhythms synchronization using fractional differential equations system of coupled van der Pol oscillators 被引量:1
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作者 J. E. Escalante-Martfnez J. F. Gomez-Aguilar +2 位作者 C. Calderon-Ramon A. Aguilar-Melendez P. Padilla-Longoria 《International Journal of Biomathematics》 SCIE 2018年第1期313-336,共24页
This paper presents an alternative representation of a system of differential equations qualitatively showing the behavior of the biological rhythm of a crayfish during their transition from juvenile to adult stages. ... This paper presents an alternative representation of a system of differential equations qualitatively showing the behavior of the biological rhythm of a crayfish during their transition from juvenile to adult stages. The model focuses on the interaction of four cellular oscillators coupled by diffusion of a hormone, a parameter μ is used to simu- late the quality of communication among the oscillators, in biological terms, it mea- sures developmental maturity of the crayfish. Since some quorum-sensing mechanism is assumed to be responsible for the synchronization of the biological oscillators, it is nat- ural to investigate the possibility that the underlying diffusion process is not standard, i.e. it may be a so-called anomalous diffusion. In this case, it is well understood that diffusion equations with fractional derivatives describe these processes in a more realis- tic way. The alternative formulation of these equations contains fractional operators of Liouville-Caputo and Caputo-Fabrizio type. The numerical simulations of the equations reflect synchronization of ultradian rhythms leading to a circadian rhythm. The classical behavior is recovered when the order of the fractional derivative is V = 1. We discuss possible biological implications. 展开更多
关键词 Circadian rhythm van der Pol oscillators Liouville-Caputo fractional oper-ator Caput^Fabrizio fractional operator Adams Bashforth Moulton method syn-chronicity.
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Initial position estimation strategy for a surface permanent magnet synchronous motor used in hybrid electric vehicles 被引量:3
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作者 Bing TIAN Qun-tao AN +2 位作者 Li SUN Dong-yang SUN Jian-dong DUAN 《Frontiers of Information Technology & Electronic Engineering》 SCIE EI CSCD 2016年第8期803-813,共11页
A novel nonlinear model for surface permanent magnet synchronous motors(SPMSMs) is adopted to estimate the initial rotor position for hybrid electric vehicles(HEVs). Usually, the accuracy of initial rotor position... A novel nonlinear model for surface permanent magnet synchronous motors(SPMSMs) is adopted to estimate the initial rotor position for hybrid electric vehicles(HEVs). Usually, the accuracy of initial rotor position estimation for SPMSMs relies on magnetic saturation. To verify the saturation effect, the transient finite element analysis(FEA) model is presented first. Hybrid injection of a static voltage vector(SVV) superimposed with a high-frequency rotating voltage is proposed. The magnetic polarity is roughly identified with the aid of the saturation evaluation function, based on which an estimation of the position is performed. During this procedure, a special demodulation is suggested to extract signals of iron core saturation and rotor position. A Simulink/MATLAB platform for SPMSMs at standstill is constituted, and the effectiveness of the proposed strategy is verified. The proposed method is also validated by experimental results of an SPMSM drive. 展开更多
关键词 Surface permanent magnet synchronous motor(SPMSM) Initial position estimation Nonlinear model Hybrid injection Position observer
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