水泥乳化沥青碎石基层材料性能与应用

为改善水泥稳定碎石基层性能,以获得一种既保持水稳碎石高强度特点,又能最大程度避免反射裂缝,同时也经济可行的大规模路网改造用基层材料,试验中将低剂量(3.5%以下)与加入乳化沥青(2.1%以下,60%含量沥青)结合起来,先通过马歇尔试验选择了2.5%水泥、1.8%乳化沥青的合理用量,然后对其进行了无侧限抗压强度与变形、干缩、水稳定性、劈裂等试验,最后通过试验路验证了其使用功能。试验结果表明:按以上配比加入乳化沥青后,无侧限强度变异性较小,强度代表值与不加沥青时基本相同;水稳定性增加;干缩应变约减少27%,且失水过程减缓;劈裂强度略有降低;长期观测的表面反射裂缝情况明显改善。     

施工企业信用评价体系构建

随着我国市场经济的不断发展,建筑市场各方主体“信用危机”的出现已经严重阻碍了我国建筑业持续、稳定、健康的发展。我国对建筑市场信用体系的研究还处于初始阶段,此文以施工企业信用的制度经济学定义为基本出发点,揭示施工企业信用的内涵,论述建立施工企业信用评价体系的意义,进而构建施工企业信用评价指标体系,为我国建筑市场信用体系的建设和研究提供一块基石。     

Transport planning and the policy-modelling interface

Evidence of the inability of transport models to elucidate policy is cited and reasons for this weakness are then suggested.Attention is drawn to the fundamental changes in both opinion and policy currently taking place. There is less concern with accessibility per se and rather more concern with the provision of adequate or minimum accessibility for certain social groups. More emphasis is placed also on the environmental aspects of transportation.The implications of these changes are outlined. It is not at all clear that the need to adapt and up-date models is appreciated widely enough. Finally, it is considered whether fundamental changes in methodology may help to make transport models more responsive to policy needs.     

Analytical Tire Models for Dynamic Vehicle Simulation

Four basic tire models suitable for dynamic vehicle simulation are formulated. The models are compared through a six-degree-of-freedom nonlinear simulation of a cargo truck crossing rough ground. Guidelines are developed for the selection of an optimum tire model for a given dynamic vehicle simulation.     

Some Thoughts on Flags of Convenience

The purpose of this article is to formulate the problem, to assess its magnitude, and at the same time to suggest the areas that must be investigated before any practical policy recommendations can be made.     

“伯克”级驱逐舰反导能力分析

美国海军的“伯克”级驱逐舰拥有强大的对地攻击能力,卓越的防空和对舰作战能力。本文剖析了“伯克”级驱逐舰的反导作战思想,对其探测跟踪能力,作战反应能力以及打击平台,区域防空,点防御和电子战等方面的能力进行详细的讨论,从而找出其反导作战存在的薄弱点,为反舰导弹突防研究提供参考。     

Developing Metro Systems in the People’s Republic of China: Policy and Gaps

Rapid urbanization has taken place in China since the Open Policy in 1978. In face of the growing demand for mobility in large cities, new metro systems were developed in large cities like Guangzhou and Shanghai. At present, there are seven cities with 10 metro lines under construction. What are the policy issues and major challenges of developing metro systems in China? This paper systematically reviews the current situation and highlights three major gaps that Chinese cities have to overcome in planning metro systems. They are the technology gap, the financing gap and the affordability gap. A discussion of these gaps in the Chinese context leads us to the conclusion that early planning and careful studies are important in the development of metro systems in China. Moreover, the existing official criteria (population and economic power) for approving the building of metro systems are insufficient and should be supplemented by more vigorous evaluation criteria.     

The applicability of non-cooperative game theory in transport analysis

Various models that incorporate concepts from Non-Cooperative Game Theory (NCGT) are described in the transport literature. Game Theory provides powerful tools for analysing transport systems, but these tools have some drawbacks that should be recognised. In the current paper we review games that describe transport problems and discuss them within a uniform context. Although the paper does not introduce new tools, it presents insights concerning the relations between transport models and games. We divide existing games into groups and show that some common features characterise multiple games. We distinguish between games that make a conceptual contribution and games that are suitable for application. Compact or symmetric game structures make remarkable observations but often do not support actual decision-making. Less aesthetic formats, most of which are Stackelberg games between authorities and travellers, are stronger as instruments that assist in determining real-life policies; these formulations can be treated by practitioners as mathematical programs with equilibrium constraints and not as games. Yaron Hollander is currently conducting economic research of bus reliability at the Institute for Transport Studies at the University of Leeds. He previously worked for the Technion—Israel Institute of Technology; for the Israel Institute for Transportation Planning and Research; and for the public transport department at Ayalon Highways Co. Joseph N. Prashker is a professor at the Faculty of Civil and Environmental Engineering at the Technion—Israel Institute of Technology. Till recently he served as head of the Transportation Research Institute at the Technion. His interests are behavioural demand models, network analysis, and Game Theory applications in transportation.