通用汽车公司中国市场拓展策略及启示

从通用汽车公司在中国的发展历程入手,重点剖析了通用汽车公司迅速拓展中国市场的主要策略,并由此得出企业开拓国际市场的几点启示。     

重庆山区绕城高速公路立交规划与思考

文章以重庆绕城高速公路立交规划布局为研究基础,对城市外环高速公路立交的布局、等级、技术条件、类型和方案进行了较深入的探讨,并结合工程实践,提出了关于城市外环立交规划布局的几个关键问题的意见和建议。     

Simulating deep CO2 emission reduction in transport in a general equilibrium framework: The GEM-E3T model

Transport sector restructuring to achieve deep GHG emission cuts has attracted much attention because transportation is important for the economy and inflexible in greenhouse gas emission reduction. The aim of this paper is to simulate transition towards low carbon transportation in the European Union until 2050 and to assess the ensuing macroeconomic and sectorial impacts. Transport restructuring is dynamically simulated using a new transport-oriented version of the computable general equilibrium model GEM-E3 which is linked with the PRIMES-TREMOVE energy and transport sectors model. The analysis draws from comparing a reference scenario projection for the EU member-states up to 2050 to alternative transport policy scenarios and sensitivities which involve deep cutting of CO₂ emissions. The simulations show that transport restructuring affects the economy through multiple channels, including investment in infrastructure, the purchasing and manufacturing of new technology vehicles, the production of alternative fuels, such as biofuels and electricity. The analysis identifies positive impacts of industrial activity and other sectors stemming from these activities. However, the implied costs of freight and passenger transportation are of crucial importance for the net impact on GDP and income. Should the transport sector transformation imply high unit costs of transport services, crowding out effects in the economy can offset the benefits. This implies that the technology and productivity progress assumptions can be decisive for the sign of GDP impacts. A robust conclusion is that the transport sector decarbonisation, is likely to have only small negative impacts on the EU GDP compared to business as usual.     

荆门市综合交通运输系统总体布局规划

文章运用区域综合交通规划学、系统工程学、区域经济学和旅游经济学等多学科研究方法,针对我国“十二五”期间大力发展旅游业和优先建设交通基础设施的特殊背景,以荆门市交通运输系统为研究对象,综合考虑城市交通、过境交通、旅游交通及其各种交通方式的综合协调,对荆门市的综合交通运输网络进行总体布局规划。     

Statistical and machine learning approach for planning dial-a-ride systems

Door-to-door transportation service for elderly and persons with disabilities is often called dial-a-ride (DAR), and is usually provided by transit agencies through private contractors. Growth in DAR ridership is reported across the United States and this tendency will likely continue due to aging population. Such trends encourage development of models that can provide decision support in planning new DAR systems or expanding existing ones. Several statistical models were previously developed to predict the required DAR system capacity, given various characteristics of the service region, level-of-service requirements and operator constraints. Our work contributes to this line of research by proposing statistical and machine learning approaches that provide more accurate predictions over a wider range of scenarios. This is accomplished through transformation of variables and application of generalized linear model and support vector regression. Proposed models are built into an online tool that can help transit planners and policy makers: (a) estimate the capacity and operating cost of a DAR system needed to provide the desired level of service, (b) explore tradeoffs between system costs and levels of service, and (c) compare the cost of providing DAR service with other transportation alternatives (e.g., taxi, conventional transit).     

27t轴重通用货车应用下调车场连挂区调速控制研究

27 t轴重通用货车的应用给调车场连挂区调速控制提出了新问题。分析27 t轴重通用货车单位基本阻力更小、溜放动能更大等特点,减速顶对27 t轴重通用货车制动功的减小、临界制动速度的上浮等特性,以及与既有货车混合应用后超速连挂风险的增加、调速控制复杂性的增大等问题。通过模型建立、参数标定及仿真计算,得到减速顶对27 t轴重通用货车制动功的减幅及临界制动速度的漂移量。为解决27 t轴重与既有货车混合应用下调车场连挂区调速控制问题,提出3种调速控制方案,仿真计算显示,在满足27 t轴重通用货车调速控制、难行车不利溜放、最短溜放距离等约束下,增加布顶与调整坡度相结合的方案最优。     

肯尼亚蒙内铁路EMALI制枕场总体规划设计研究

基于肯尼亚新建蒙巴萨至内罗毕标轨铁路Emali制枕场生产项目,探讨建设科学合理、物流顺畅、经济高效的现代化轨枕预制工厂。从制枕场生产参数确定、生产工艺选择、工艺方案布置、流水节拍设计以及设备配置等方面进行详细研究,优化工艺流程和设备配置方案。为了轨枕生产中各工序衔接顺畅,生产厂房按照车间跨度的划分进行工艺布置和流水节拍控制,避免各台位之间相互干扰,有效提升轨枕生产效率。实现轨枕厂建设规模化、标准化、规范化的目标,也为海外标轨铁路项目的制枕场规划设计提供参考。     

防城港港区铁路规划方案研究

防城港港区既有铁路运输能力已接近饱和,为满足港区规划新增运量的运输需求,需对港区铁路改扩建方案进行规划研究。在详细分析港区既有铁路、运量预测和发展规划的基础上,提出港区设置3个车场和设置4个车场两个方案。通过对三场、四场方案的深入研究比选,推荐三场方案作为港区铁路规划方案。推荐方案不仅能满足港区未来新增吞吐量的集散需求,也对西南铁路出海大通道海铁联运的发展提供有力支撑。     

海洋核动力平台大破口事故下安全壳压力控制与影响

安全壳是海洋核动力平台的核安全二级耐压舱室,包容反应堆及一回路系统,是设计基准事故工况下限制放射性物质对环境释放的重要屏障。海洋核动力平台采用分散式压水堆型,主管道大破口是一种严重的设计基准事故,导致安全壳内产生高压高温的放射性气体。文章通过对安全壳压力控制技术的对比研究,提出了海洋核动力平台安全壳设计适合采用湿阱抑压控制措施的建议,并研究了压力控制对总体方案改进带来的收益,对海洋核动力平台总体方案设计具有指导意义。     

不同类型船舶的灭火对策

分析了不同类型船舶的共性和特性,有针对性地阐述对不同类型船舶火灾的扑救对策,以达到最好的灭火效果。