Modelling of wheels and rail discontinuities in dynamic wheel-rail contact analysis

A classification of wheel-rail contact is given. Difference is made between modelling of a running wheel with continuous single-point-contact, as is common practice in wheel-rail contact analysis, and a wheel with transient double- or multi-point-contact, which may occur for rail irregularities with curvatures larger than that of the wheel circumference. It is shown that application of the first model for these irregularities will strongly underestimate the contact forces as it does not describe occurring mechanisms correctly. Further, it is shown that in principle it is not possible to describe the second type of contact fully correct with a lumped wheel model. Both wheel models are formulated mathematically for some basic contact cases. Afterwards, results are applied to a linear track model. Analytical closed-form solutions are found in the frequency domain for arbitrary type of contact and numerically transformed to the time domain. Finally, the necessity is shown to avoid situations where transient multiple-point-contact may occur (like rail joints) in practice.     

百色市交通运输业发展现代物流问题初探

交通运输是现代物流系统最重要的基础功能。文章阐述了百色市交通运输物流业发展的现状，分析了百色市发展交通运输物流业存在的主要问题以及发展现代物流的必要性和有利条件，提出了百色市交通运输业加快向现代物流业融入和拓展的对策。     

城市轨道交通客流密集度指数研究

基于轨道交通物联网监测数据，从点、线、面三个层级，构建不同时间粒度车站、线路、网络的客流密集度指数计算模型和算法。车站客流密集度指数模型综合考虑影响车站密集度指数的关键区域（出入口、站台、楼扶梯、换乘通道）的拥挤程度和拥挤范围因素；线路的客流密集度指数模型综合考虑车站和区间的影响；网络的客流密集度指数模型由各线路的客流密集度指数加权得到。测试结果表明，提出的模型计算结果与实际地铁客流出行规律一致，可较好地反映地铁拥挤程度，为地铁客流运营拥挤状态评价和辅助决策提供技术支持。     

试论核电设备道路运输特点及应对措施

结合核电设备的特性,论述核电设备道路运输的特点,并提出相应的对策措施,以达到安全、及时、万无一失的运输目标,为我国掀起的新一轮核电建设高潮服务。     

铁路计量与安全

结合铁道技术监督工作,从铁路安全的重要关注点、铁道技术监督工作安全的基本要求和保证铁道技术监督工作质量安全的措施3个方面,介绍铁路计量与安全的关系。详细阐述计量与测量的区别和联系,总结铁路计量的特点、主要工作内容和发展方向。     

Transportation and income inequality in China: 1978–2007

This paper mainly studies how various types of transportation modes are associated with income inequality in China for the years between 1978 and 2007. Gini coefficients are used to measure the income inequality nationwide, and within urban and rural areas of China. Factors other than transportation are also considered in the regression model, including a few demographic variables and major economic indicators. We contribute to the literature by examining the income redistributive effects of transport infrastructure and services, and providing transport planning and policy guidance which may alter the orientation of public policy and help alleviate the growing social and economic imbalance in China.     

真空管道运输系统管道模型结构分析与实验内容

对真空管道运输(ETT)系统管道实验模型的整体结构和尺寸、主要功能部件的设置以及该管道实验模型建成后将进行的实验内容等进行了分析和介绍。     

京津冀一体化轨道交通协调发展研究和展望

京津冀协同发展上升为国家战略,需要区域轨道交通协调发展来支撑和服务于区域一体化发展。从京津冀协同发展空间布局及产业转移的角度出发,提出各种轨道交通的层次及服务功能,在此基础上对轨道交通协调发展研究提出应抓住规划,处理好既有轨道交通与新增轨道交通、客货运主要通道与交通引导(TOD)、各种轨道交通间协调衔接等方面关系;加快投融资改革,实施同步建设;创新体制,实现管理协调发展;加大政策扶持,达到轨道交通可持续发展等方面进行研究,同时对区域轨道交通进行展望,对京津冀一体化轨道交通协调发展研究方向、研究领域和空间进行了浅议。     

浅谈香港西铁项目计划管理

香港西铁项目投资规模巨大，工程复杂。为确保工程能按时完工，投入运营，参与各方秉承科学计划管理理念、采用先进技术精心组织实施，业主在招标阶段制定了一套完善的计划管理体系，承包商能够利用先进技术编制了全面、详细、形象的施工计划并加以实施，咨询工程师能够严格把关，协调各方关系，确保了项目顺利完工。     

Passenger railway reform in the last 20 years - European experience reconsidered

It is about 20 years since the rail reform process in Europe began with the separation of infrastructure from operations in Sweden. This paper reviews the entire process, examining the objectives of reform, the different models adopted, and the key elements of separation of infrastructure from operations, competition both through open access and franchising and regulation and infrastructure charging. It is concluded that separation of infrastructure from operations involves costs, but is the most effective way of achieving within mode competition. Where operations do not greatly overlap and open access passenger and freight are unimportant, leasing infrastructure to passenger franchisees may be effective, but the model of vertical integration as separate subsidiaries within a holding company structure makes it difficult to ensure a level playing field for new entrants and is only effective where the vertically integrated operator remains dominant.