直线电机在城市轨道交通中的应用

本文介绍了直线电机驱动车辆的特点,在此基础上,阐述了直线电机运载系统在我国城市轨道交通的应用前景.     

浅析电机绝缘老化的原因及解决措施

电机是在我们生产广泛使用的电气设备之一,其可以实现电能和机械能之间的相互转化,但在电机使用过程中,很多因素都会使电机使用的安全性和可靠性受到影响,而这其中最为重要的影响因素即是电机绝缘老化的问题。文章中对电机绝缘老化的原因进行了分析,并进一步对电机绝缘老化的预防和解决措施进行了具体的阐述。     

基于电机故障诊断的新方法

本文介绍了基于定子电流Park量、电机功率频谱分析、电机振动信号的分析新方法在电机故障诊断中的应用,分别比较了它们在应用中的优劣,及与其他新理论相比的优点     

矿用防爆电机现状及发展趋势

文章在介绍了防爆电机的基本原理及其发展概况的基础上，重点分析了国内矿用防爆电机的生产技术现状．对矿用防爆电机的发展趋势作了科学的预测。     

开关磁阻电机调速系统综述

随着电力电子、微电脑和控制技术的迅猛发展,开关磁阻电机逐渐发展成为一种新型调速驱动系统.它具有结构简单、运行可靠及效率高等突出特点,成为交流电机调速系统、直流电机调速系统和无刷直流电机调速系统的强有力的竞争者,引起各国学者和企业界的广泛关注.本文首先对开关磁阻电机的基本工作原理和特点做以介绍;然后针对开关磁阻电机的运行状态建立了用状态方程表示的非线性动态模型,系统地概述该电机的应用和研究现状;最后将该电机与其他电机在设计和运行性能等方面进行比较,进一步了解该电机的特点和发展趋势.     

开关磁阻电机调速系统综述

随着电力电子、微电脑和控制技术的迅猛发展,开关磁阻电机逐渐发展成为一种新型调速驱动系统。它具有结构简单、运行可靠及效率高等突出特点,成为交流电机调速系统、直流电机调速系统和无刷直流电机调速系统的强有力的竞争者,引起各国学者和企业界的广泛关注。本文首先对开关磁阻电机的基本工作原理和特点做以介绍;然后针对开关磁阻电机的运行状态建立了用状态方程表示的非线性动态模型。系统地概述该电机的应用和研究现状;最后将该电机与其他电机在设计和运行性能等方面进行比较,进一步了解该电机的特．点和发展趋势。     

变频器在预制场龙门吊车同步电机中的运用

我司在若干个桥梁预制梁加工厂建设中实用了龙门吊,龙门吊跨度37.5米,左右轨道支腿采用了1.5KW的纵向驱动电机,在实用过程中,左右支腿曾发生电机不同步现场,导致大梁扭曲,几乎发生安全事故,后采用变频器在电机同步方面进行控制系统改良,很好地解决了该问题,设备一直实用完好。     

赴日本考察机电一体化技术

由上海电器科学研究所李平等同志组成的机电一体化考察组,于1985年12月5日至20日对日本进行了考察。在日期间,考察组参观访问了三菱电机、寺崎电气、立石电机、神钢电机、光洋电子、三信     

混合电动汽车电机控制器检测与诊断系统原理及其常见故障

混合电动汽车在正常工作过程中．电机控制器故障发生的过程就是其技术状况变化的过程,这种变化必然会通过驱动电机系统参数反映出来,有丰富经验的技术人员根据这些参数的变化情况可以判别出电机运行的好坏、诊断出电机控制器的故障。因此,检测与诊断系统的基本任务就是实现电机运行工况参数的自动采集和显示、电机控制器运行状况在线检测与诊断方法,达到提高电机控制器系统检测与诊断的准确性、工作效率以及减轻对技术人员要求的目的。     

浅析直线振动筛常见问题及解决对策

直线振动筛作为选煤厂的重要设备之一，在长期使用过程中，会有不同的问题发生，所以为了保证选煤厂的正常生产经营，需要针对直线振动筛在使用过程中常见的问题进行具体的分析，从而有针对性的解决。文中对直线振动筛的工作原因及特点进行了分析，并对其运行中的常见问题进行了说明，同时进一步对这些常见问题提也了具体的解决措施。     

一级方程式(F1)赛车产业创新及其动力机制研究

以熊彼特的创新理论为分析框架,全面地解构了F1赛车产业领域内的创新。F1赛车产业创新涉及产品创新、技术创新、市场创新、材料创新和制度创新5个方面,创新动因主要有竞争压力、重要知识激发、预期利润压力、赛车产业集群和规则的变动等。     

中国汽车企业对外直接投资中的技术获取路径——上汽集团并购韩国双龙的案例研究

研究了中国汽车企业通过对外投资获取外部技术的路径,并以上汽集团控股韩国双龙汽车公司为案例,分析了上汽集团采取的技术获取路径。案例研究结果显示:上汽集团主要通过国产化、技术转让和共享生产平台从双龙汽车公司获得技术;但是,对计划实施难度估计不足、双龙工会的强势力量和频繁罢工,导致上汽集团未能如愿以偿。最后指出,变"拉式"国产化为"推式"国产化更有利于企业从外部获取技术。     

Consumer confidence and rational expectations in the United States compared with the United Kingdom

This paper examines the relationship between consumer confidence and the Rational Expectations Permanent Income Hypothesis in the USA and compares the results with those obtained for the UK. The study expands previous analysis by defining consumption as motor vehicles, goods excluding motor vehicles, and services. The results suggest that predictive ability of the USA's consumer confidence is less than that of the UK, but that contrary to the UK study, confidence does not predict future consumption growth of services and is therefore consistent with Rational Expectations Permanent Income Hypothesis.     

Understanding the cell phone effect on vehicle fatalities: a Bayesian view

This article examines the potential effect of various factors on motor vehicle fatality rates using a rich set of panel data and classical regression analysis combined with Bayesian Extreme Bounds Analysis (EBA), Bayesian Model Averaging (BMA) and Stochastic Search Variable Selection (SSVS) procedures. The variables examined in the models include traditional motor vehicle and socioeconomic factors. In addition, the models address the effects of cell phone usage on such accidents. The use of both classical and Bayesian techniques diminish the model and parameter uncertainties which afflict more conventional modelling methods which rely on only one of the two methods.     

Production and costs in the South African motor vehicle industry

This study investigates the existence of economies of scale in the South African motor vehicle industry as well as the substitution possibilities between input pairs and the direct and cross-price elasticities of demand for the various inputs. Because of data limitations, a translog cost function was estimated for only a three input model corresponding to a homogeneous production function involving capital, labour and intermediate goods. The issue of the existence of economies of scale in the South African motor vehicle industry is a particularly important one because South Africa once again is a member of GATT and a full participant in the international trade arena. The null hypothesis of constant returns to scale was rejected at the 0.5% level of significance. Thus, the results of this model are certainly consistent with economies of scale in the South African motor vehicle industry. The estimated direct price elasticities were consistent with the hypothesis that, during the past two decades, capital was the productive factor with the most elastic demand, and the estimated cross-elasticities between input pairs generally supported the hypothesis that all inputs are substitutes.     

Energy demand in the transportation sector of Mexico

This paper report results of an analysis of the demand for energy in the Mexican transport sectors, focusing on the railroad, air transport and motor vehicle modes. The approach is an econometric one with emphasis placed on the structure for each mode. For two of the modes a two-stage approach is employed where in the first stage demands for services from the particular mode are modeled, and in the second stage demand is treated as a derived demand from these transport services. For the motor vehicle mode, gasoline demand is considered as the product of gasoline consumption per vehicle times the total number of vehicles, and then these components are related to economic and structural variables. Diesel demand of motor vehicles is modeled in a more reduced from approach. The principal finding is that changes in income play a more important role in affecting energy demand than do changes in energy prices, especially in the railroad and air transport sectors. For the gasoline and diesel fuel demand in the monitor vehicle sector, however, price is of substantial importance.     

湖北汽车制造业基于绿色制造的科技发展战略

介绍了湖北传统汽车制造业的现状和存在的问题,在此基础上对湖北汽车制造业如何构建绿色制造科技发展战略进行了剖析。     

The Economics of Law: Economic Imperialism in Negligence Law,No-Fault Insurance,Occupational Licensing and Criminology?

The aim is to examine the contribution which economic and quantitative analysis can make to a better understanding of the law. I concentrate on the common law action of negligence and how it is related to the optimal deterrence of accidents, rather than to the compensation of all accident victims. A critique is made of the New South Wales Law Reform Commission's proposal to prohibit negligence actions for motor vehicle accidents and to introduce a compulsory ‘no-fault’ scheme. An econometric analysis of new Zealand and Australian ‘no-fault’ schemes finds that the negligence system appears to have some deterrent effect on motor vehicle accidents.     

The automobile road to technological change : Diffusion of the automobile as a process of technological substitution

Advancement of the motor vehicle and its production methods is analyzed as a process of technological change. In a broader context, motor vehicles evolved as an integral component of road transportation through a series of interlaced substitutions of old by new technologies. Building on a large number of studies that described technological substitution processes, first it is shown how new energy forms replaced their predecessors and how the old marine-transport technologies were substituted by new ones. These examples constitute some of the oldest, empirically documented technological changes and show that many events in the dynamics of energy substitution and marine transport are related to technological changes in road transportation. It is shown that these substitution processes can be described by simple rules and that the replacement of old by new technologies in the energy and transport systems lasted about 80 years. The technological changes within road transportation, however, were more rapid. Replacement of horses by automobiles and older by newer generations of motor vehicles and production methods lasted only a few decades in the United States. Thus, technological substitutions within the road-transportation system were considerably shorter than the expansion of railroads, surfaced roads, all road vehicles together, and the more recent expansion of air transportation.     

Alcohol availability and alcohol-related motor vehicle accidents

The impact of alcohol availability on alcohol-related motor vehicle accidents centres on the sensitivity of consumption to changes in the full price of alcohol – the dollar price of alcohol plus the time and travel costs associated with acquiring alcohol. Reducing the number of licensed alcohol vendors raises the time and travel costs of alcohol; if alcohol consumption is responsive to this price increase, then drinking and driving may decrease. Using data on the 254 counties in the US state of Texas, the results in this paper show that alcohol availability has a significant impact on alcohol-related motor vehicle accidents. Thus, alcohol vendor restrictions can be an important policy tool in reducing such accidents.