平行流冷凝器在大型货车空调中的应用

空调系统是现代货车的重要组成部分,空调系统性能的优劣关系到驾驶安全。平行流冷凝器作为新一代高效冷凝器,具有体积小、结构紧凑、换热效率高等诸多优点,可提高货车空调性能。本文就平行流冷凝器在大型货车上的应用进行了分析,总结出：在货车上应用平行流冷凝器不仅投资可减少,还可以降低油耗和变暖总当量（TEWI）,节能和环保效果较好...     

The melting Arctic and its impact on China’s maritime transport

The shrinking of Arctic ice triggers off a new round of competition and dispute in this region, among traditional Arctic states and non-Arctic actors. Like its East Asia neighbours, China sees the melting Arctic Ocean a unique opportunity for itself and international trade generally. The changing physical landscape of the Arctic region will certainly have a major impact on China’s economic future which is very dependent on international shipping. This paper assesses the impact of the ice-free Arctic on the development of marine transport industry in China. The author discusses the potential new routes with the Arctic’s melting and the opportunities that it brings to China’s maritime transportation industry. Challenges that China faces in future shipping through the Arctic will be also addressed from political, legal, economic and environmental dimensions, followed by a preliminary exploration of ways to solution of these challenges.     

单坡型桥梁混凝土护栏裂纹防撞性能影响分析

由于混凝土材料抗拉强度低的特点,单坡型桥梁钢筋混凝土护栏通常是带裂纹工作的。为了研究裂纹对于单坡型桥梁钢筋混凝土护栏防撞性能的影响,总结了单坡型桥梁钢筋混凝土护栏裂纹特点,并进一步分析了单坡型桥梁钢筋混凝土护栏裂纹的类型。在此基础上,本文采用文献资料调研、理论分析以及计算机仿真方法分析了单坡型桥梁钢筋混凝土护栏裂纹对其防护能力的影响,认为虽然混凝土材料在裂纹处不连续,但由于钢筋的存在,不会影响护栏作为纵向的连续结构整体发挥安全防护作用,因此裂纹对单坡型桥梁钢筋混凝土护栏的防护能力没有影响。本文最终通过实车碰撞试验对分析结果进行了验证。     

The impact of flooding on road transport: A depth-disruption function

Transport networks underpin economic activity by enabling the movement of goods and people. During extreme weather events transport infrastructure can be directly or indirectly damaged, posing a threat to human safety, and causing significant disruption and associated economic and social impacts. Flooding, especially as a result of intense precipitation, is the predominant cause of weather-related disruption to the transport sector. Existing approaches to assess the disruptive impact of flooding on road transport fail to capture the interactions between floodwater and the transport system, typically assuming a road is fully operational or fully blocked, which is not supported by observations. In this paper we develop a relationship between depth of standing water and vehicle speed. The function that describes this relationship has been constructed by fitting a curve to video analysis supplemented by a range of quantitative data that has be extracted from existing studies and other safety literature. The proposed relationship is a good fit to the observed data, with an R-squared of 0.95. The significance of this work is that it is simple to incorporate our function into existing transport models to produce better estimates of flood induced delays and we demonstrate this with an example from the 28^th June 2012 flood in Newcastle upon Tyne, UK.     

The impacts of strait and canal blockages on the transportation costs of the Chinese fleet in the shipping network

ABSTRACT

Straits and canals have always served as key nodes in shipping networks. The blockage of a strait or canal will lead to ship deviations and increased transportation costs. To measure this impact on the Chinese fleet, our study develops a mathematical model that is based on a programming formulation. Each strait or canal is assumed to be blocked in turn, and the increased transportation costs for the Chinese fleet in different scenarios are calculated and compared using the proposed programming formulation in order to measure the impact of the blocked strait or canal on the Chinese fleet. Larger increases in transportation costs have greater impacts on the fleet. The results show that a blockage of the Strait of Hormuz would have the greatest impact of all straits and canals; it would cause the Chinese fleet to lose a portion of its import and export market, and such a blockage cannot be addressed through ship deviations. Based upon increased transportation costs, the four straits or canals that would have the greatest impact if blocked are the Mandeb Strait, the Suez Canal, the Sunda Strait and the English Channel.     

汽车—乘员三维多体系统碰撞仿真研究

本文以碰撞动力学和多体系动力学中的Ｒ－Ｗ方法为理论依据，建立了汽车－乘员三维多体系碰撞模型。在此基础上，开发了汽车碰撞计算机仿真软件ＳＶＣ３Ｄ。仿真计算与试验结果的对比证明了模型的合理性及软件的正确性。     

两次动作的双安全气囊系统

提出一种两次动作的新型双安全气囊系统，并介绍了该系统的工作原理，结构和设计要点。在低速（小于３０ｋｍ／ｈ）冲撞时，该系统只起动安全带预紧器，在高速冲撞时，安全带预紧器和双安全气囊同时起动，从而保护驾乘人员的安全     

公路大件运输计算机决策系统的研制与开发

公路大件运输是公路运输的一种重要的形式。大件运输的货物往往是国家重点建设项目的关键设备,在运输过程中通常要求具有很高的可靠性和安全性。本文系统分析了公路大件运输安全性的影响因素,建立了运输车辆的可靠性、稳定性和通过能力模型,并在此基础上用VB语言开发出了公路大件运输计算机决策系统。试用结果表明,该软件能迅捷、有效地解决公路大件运输的可靠性、稳定性和通过能力的决策问题。     

轻型客车正面碰撞车架吸能结构优化设计

非承载式车身结构的轻型客车发生正面碰撞时,车架是主要变形吸能结构。因此,根据正面碰撞安全法规对某轻型客车的碰撞安全性改进设计中,以车架改进为重点,采用计算机模拟和试验相结合的方法优化设计了车架吸能结构,控制了车架的刚度和变形,为整车通过我国正面碰撞安全法规奠定了坚实的基础。项目进行过程中在国内首次将大规模网络集群并行计算技术应用于汽车领域,同时开创性地进行了车架总成动态冲击试验。改进实践证明,类似结构的车辆可以通过对车架吸能区结构的优化设计,在短时间内以较低的代价显著提高碰撞安全性能。     

微型客车白车身碰撞特性的试验研究

为研究某微型客车的正面碰撞性能，验证通过“逆向工程法”所建立的白车身正面碰撞仿真模型，进行了白车身的正面碰撞试验。详细叙述了试验的准备、试验方法和结果。所得到的白车身加速度以及冲击力时间历程曲线等试验数据可以用来验证白车身有限元碰撞模型。