基于压电陶瓷的轨道振动能量采集方法

提出一种轨道竖向振动能量采集的新方法.基于轨道竖向振动的激励模型,建立轨道竖向振动理论模型;基于压电陶瓷,建立轨道振动能量转换耦合模型.初步探讨了轨道振动能量采集对轨道安全性的影响,同时对轨道振动能量采集的规模和最佳负载进行了初步估算.结果表明,电能以短暂、爆发性的方式输出,需要匹配快速能量回收电路与储能元件.所提出的轨道振动能量采集方法为轨道竖向振动能量采集、回收和再利用提供了一种可能的途径.     

Regulatory reform and freight mode choice

Reform of trucking Vehicle Weights and Dimensions (VWD) regulations in Canada is now underway. The effect these reforms will have on the freight transportation industry are only recently the subject of research. This paper is part of this new research effort, aimed at understanding how regulatory reform in the trucking sector will affect the existing competitive relationship between trucks and the railways. The paper presents the results of study and research into modelling the relationship between mode choice and the service characteristics that are affected by VWD reform.Using several periods of data, a series of econometric models are developed which help to elucidate the relative relationships between the mode service characteristics for both of the principal interprovincial freight modes. A technique is developed and presented to model railway user costs in order to overcome the complex and often unrepresentable pricing activities of Canadian railways.The strength of the developed econometric models is presented, including their significance and statistical reliability. This is further reinforced by the similarities exhibited by all the models in the series. The selected model is applied to predict market service responses required of the railway industry in order to compete with the trucking sector now adapting to the new regulations.The impact of the newly implemented vehicle weight and dimension reform on the rail transportation industry is analyzed and railway industry improvements aimed at maintaining its market share are presented. The results predicted by the model show that railway user cost reductions should be moderate, and likely less than the level of inflation over the period of time when trucking converts its fleet to take advantage of the new regulations.Abbreviations AASHTO American Association of State Highway and Transportation Officials - CCMTA Canadian Conference of Motor Transport Administrators - EPI End products, inedible commodity classification - GVW Gross Vehicle Weight - NA 1988 VWD National Agreement - RTAC Roads and Transportation Association of Canada - VWD Vehicle Weight(s) and Dimension(s) - WA 1988 VWD Western Agreement     

Modeling intrametropolitan industrial location realistically

This paper compares intrametropolitan industrial location models to the process of intrametropolitan industrial location as described in the real estate and urban economic literature. It identifies seven areas where industrial location models are at odds with reality, and suggests ways to make them realistic. Specifically, it makes a case for microanalytic/stochastic/recursive/dynamic/economic industrial location models. It goes on to describe an operational model that is realistic in most respects.     

轿车车身静态刚度计算及静态竖直弯曲刚度优化分析

采用UG软件建立了某国产轿车白车身静态分析有限元模型，计算并验证了其主要工况下的静态扭转特性，并进行了轿车车身静态弯曲挠度关于板单元厚度的灵敏度计算分析。针对分析结果进行了具体加强刚度的优化设计。     

一种基于预测的电控汽油机怠速稳定性控制方法

根据发动机怠速工作过程的非线性、时变性和不确定性，分析了传统怠速稳定性控制的控制机理及存在的不足，提出了一种基于预测的发动机怠速稳定性控制方法——动态矩阵预测控制(DMC)算法，并建立了预测控制模型。试验表明，该预测控制方法能够较好地克服各种不确定性因素和复杂变化对怠速稳定性的影响。     

风度A33型轿车发动机起动易熄火故障诊断分析

采用数据比较和零件互换的方法，分析了风度A33轿车发动机起动时易熄火故障产生的原因。指出对于电喷发动机轿车的故障诊断，首先要了解故障发生的条件、现象，必要时还要对故障加以验证；对于风度A33轿车，点火开关在“ON”位置处、空气流量计信号电压大于1．07V时，容易出现起动后熄火现象。     

克莱斯勒轿车无分电器点火系的故障诊断与检修

克莱斯勒汽车公司的君王、纽约客、LHS及前景牌轿车的3．3L、3．5L V6发动机均采用无分电器点火系。该点火系统由点火线圈组件、曲轴位置传感器、动力控制模块(PCM)、继电器等组成。介绍了发动机不能起动的检测与利用故障码诊断技术。另外，介绍了点火线圈的检查，曲轴位置传感器与凸轮轴位置传感器的检查，火花塞的检查方法等。     

筑路机械事故隐患分析与预防

与筑路机械相关的施工事故占道路施工事故中的绝大部分。因此，建立合理的筑路机械事故隐患分析与预防体系关系到施工企业、人员的切身利益。从筑路机械的设计拆卸安装、调试及使用中的各方面对事故隐患进行了分析，并阐述了事故预防体系。     

CAN局域网及J1939协议在货车和客车上的运用

叙述了CAN总线网络的特点及J1939协议的原理、内容及协议的应用。并设计最小节点实现应用J1939协议的CAN局域网的数据通信功能。