重载铁路轨道结构受力特性仿真分析

重载铁路朝大轴重、高运量、高密度的方向发展,对轨道结构提出了更高的需求。轨道结构在列车荷载作用下的受力特性与轨道部件尺寸、材料参数等有关。在已有研究基础上,充分结合朔黄铁路现场实测数据,采用有限元方法建立重载铁路轨道结构仿真模型,计算分析了不同轴重及不同轨道参数下的重载铁路轨道结构的受力特性(包括钢轨、轨枕、道床、路基面的弯矩、应力、变形等)。研究结果表明:列车轴重对钢轨位移与应力影响最大;采用Ⅲ型轨枕、减小轨枕间距有利于减小轨道结构受力;道床弹性模量对钢轨位移影响较大,而道床厚度对受力特性影响较小。     

悬索桥主缆钢丝腐蚀速率的影响因素分析

影响钢丝腐蚀的众多因素,分为外界环境影响因素和钢丝自身状态两大类,详细阐述了湿度、温度、大气污染物以及钢丝拉力、初期损失、主缆弯曲等各影响因素已有的实验研究成果,深入分析了上述因素对钢丝腐蚀产生影响的机理及其对腐蚀速率的影响。在得到对钢丝腐蚀产生影响的重要因素基础上,提出了需综合考虑各因素间的相互作用的多钢丝组的腐蚀实验,以达到更贴切地模拟主缆实际腐蚀过程的目的。     

单向止回阀在客车上的作用与影响

由于单向止回阀使空气弹簧无法正常工作,通过计算,车辆将在运用中会产生更加严重的问题,并提出在检修中加以改进的方案。     

短线法节段预制线形控制技术

短线法节段预制拼装技术在我国桥梁建设中已经被越来越广泛地应用,短线法节段预制拼装关键技术是短线法节段预制线形控制技术.介绍短线法节段预制基本流程及短线法节段预制线形控制的实质、原理和方法.     

Logical control approach to fuel efficiency optimization for commuting vehicles

A novel gearshift control approach for improving the fuel efficiency of the conventional commuting vehicles is addressed in this paper, where the optimization problem for gear control is formulated in the framework of stochastic logical dynamic system. By extracting the stochastic features of the driver acceleration intention in the specific route, the Markov process model is deduced and then applied for the optimization algorithm. Based on the logical system framework, the finite horizon optimization problem is solved by means of the algebraic expression of the dynamic programming algorithm with a lower computational complexity, thereby resulting in an optimal gearshift decision law in statistical sense. The software simulation and engine-in-the-loop based experiment results demonstrate the better fuel economy performance can be achieved by the proposed logic control scheme.     

陈州古城排水系统改造方案研究

陈州古城四面环湖，不仅风景秀丽而且有着浓厚的历史文化底蕴。但由于生活污水长期直接入湖，已造成湖水水质污染。为有郊遏制陈州古城的外湖、内湖水质的进一步恶化，该文通过对其独特的地理环境、地形地势的分析，并结合其经济发展水平、现状排水体制等实际情况，提出切实可行的县城排水系统改造方案。     

Influence of model domain size,wind directions and Ekman transport on storm surge development inside the Chesapeake Bay: A case study of extratropical cyclone Ernesto, 2006

The Chesapeake Bay is vulnerable to severe flooding caused by hurricanes and strong Northeasters. A 3D storm surge model of the Chesapeake Bay is developed for studying the impact of model domain size, wind directions and Ekman transport on the storm surge in the Chesapeake Bay. The model encompasses the Chesapeake Bay and the US East Coast shelf to reduce the influence of model domain size on surge prediction inside the Chesapeake Bay and to account for both local and remote wind effects. This study used 3D model experiments, with respect to different wind directions, to diagnose the relative influences of the local and remote wind effects and Ekman transport on spatial surge distribution during storm events. The model results confirmed that spatial surge distribution can be well explained by the superposition of two distinct physically driven mechanisms during a storm event: incoming surge wave caused by remote effects and local wind forcings. A large model domain is a necessity for predicting storm surge accurately inside the Chesapeake Bay. The model results suggest that the interactions of the incoming surge propagating into the Bay and the local wind forcing from N and NE directions result in an enhanced setup in the lower to middle portions of the Bay, whereas the superposition of incoming surge and the local wind forcing from S and SE directions enhance the surge in the upper Bay region. A combined northwesterly wind over the middle to upper portions of the Bay and southwesterly wind over the lower Bay can cause a large setdown throughout the entire Bay. The Ekman setup along the coast contributes significantly to the water level variations during storm events. It enhances (reduces) surge inside the Bay under the wind forcings from N and NE (SW, S, and SE) directions.     

城市公交票价调整对策之我见

改革开放以来,我国的城市公共交通事业取得了瞩目的发展,为城市经济和社会发展做出了巨大的贡献,但是由于历史的原因,公共交通的价格与价值长期背离,已严重影响了公交企业的良性发展.为此,本文就公交票价的制定原则,票价形成过程及调整对策提出一些观点和看法.     

一种轻量化翼开启式厢体的设计

本文主要介绍了一种轻量化翼开启式厢体的结构,其整体为铆接牢固的板式厢体,内部采用胶木复合木板固定在厢体骨架上,在确保厢体强度的同时,减轻了厢体自身的重量;外表面采用轻质铝合金蒙皮,美观大方。厢体两侧翼可通过安装在侧翼与前墙、侧翼与后端总成之间的四个油缸控制实现向上90°的开启,方便叉车直接在侧面进行货物装卸,装卸效率高,广泛应用于托盘产品、汽车零部件以及其它商品配送等行业。     

地铁智能交通系统（MITS）研究

“智能交通系统”是国际公认的全面解决交通运输领域问题的根本途径，其含义是”综合运用先进的信息通信、网络、自动控制、交通工程等技术．改善交通运输的运行情况．提高运输效率和安全性．减少交通事故．降低环境污染．从而建立一个智能化、安全、便捷、高速、舒适、环保的综合运输体系”。欧美日等发达国家投入了大量人力、物力和财力对ITS的诸多领域进行了广泛研究和开发.