加速公路运输业向物流的发展和融合

面对物流的新课题,一方面,运输企业要抓住机遇努力向现代物流融合,另一方面,也要从实际出发,循序渐进,充分利用现有设备,包括利用客户和其他行业现有的设施和设备,注重在调整、重组中发展物流.只有这样,我国公路运输业的现代化进程才能跃上一个新台阶.     

重庆轨道交通3号线检修通道研制

高架跨座式单轨交通的结构特点使得其运营中的检查维修工作难以展开、紧急事故应对能力差,研究设计专门的检修通道迫在眉睫。文章简要介绍重庆轨道交通3号线检修通道的功能、构成、总体设计要求、重点制作工艺,为今后跨座式单轨检修通道的制作提供依据和参考。     

海事政务中心发展思路的几点思考

文中从海事政务中心的发展角度出发,通过分析和研究其产生、存在并发展的法律依据,找出困扰其发展的问题根源,并试图从立法规范、职能定位和运行机制等方面提出推动其健康发展的有效对策。     

Policy considerations for wetland wastewater treatment in the coastal zone: A case study for Louisiana

Two major environmental problems currently affecting the Louisiana coastal zone are a high rate of wetland loss and high levels of surface water pollution. The application of secondarily treated wastewater to wetlands can be a means of dealing with both of these problems. The benefits of wetland wastewater treatment include improved surface water quality, increased accretion rates to balance a high relative water level rise due mainly to subsidence, improved plant productivity and habitat quality, and decreased capital outlays for conventional engineering treatment systems. Wetland treatment systems can, therefore, be designed and operated to restore deteriorating wetlands. Hydrologically altered wetlands, which are common in the Louisiana coastal zone, are appropriate for receiving municipal and some types of industrial effluent. While the U.S. Environmental Protection Agency has determined wetland wastewater treatment is effective in treating municipal effluent, it has discouraged the use of natural wetlands for this purpose. At the same time, funds are being used for the construction of artificial wetlands to treat municipal effluent. In the Louisiana coastal zone, however, wetlands are deteriorating and disappearing due to hydrological alteration and a high rate of relative sea level rise. If no action is taken, these trends will continue. Effluent discharge to existing wetlands should be incorporated into a comprehensive management plan designed to increase sediment and nutrient input into subsiding wetlands in the Louisiana coastal zone, improve water quality, and result in more economical waste‐water treatment. The authors believe that the Louisiana example serves as a model for other coastal areas especially in light of projections of accelerated sea level rise.     

The cost of not holding back the sea: Toward a national sample of economic vulnerability

Abstract

National and regional estimates of U.S. economic vulnerability to greenhouse‐induced sea‐level rise are produced from a sample of 30 discrete regions scattered evenly along the coastline. Scenarios that envision 50 cm, 100 cm, and 200 cm of greenhouse‐induced sea‐level rise are considered. They can be expected to place $39.2, $65.6, and $133.3 billion, respectively, (1989 dollars) of existing development in jeopardy through 2050, and $133.3, $308.7, and $909.4 billion through 2100. Sampling error and consideration of the uncertainty with which we currently view future greenhouse‐induced sea‐level rise places the 25th and 75th percentile values of expected cumulative vulnerability at $38.5 and $76.7 billion through 2050 and $132.6 and $362.4 billion through 2100. Not surprisingly, the southeast displays the largest potential vulnerability, with the northeast ranking second above both the Gulf coast and the west coast.     

舰艇声纳技术的发展动向与分析

舰艇声纳技术在现代战争中发挥着越来越重要的作用。论文介绍了舰艇声纳技术的发展历程以及装备的研制、改进情况,指出了在现代战争中发展舰艇声纳技术的优势和重要性,重点探讨了几种舰艇声纳技术的性能及其特点,最后论述了舰艇声纳技术的发展动向与分析。     

高速铁路通信信号设备接口雷电防护优化设计

提出了临界防护状态的概念,分析了临界防护状态使设备损坏的原因,提出高速铁路通信信号设备接口雷电防护优化设计方法,通过有效方法掌握被防护对象的耐冲击水平值和SPD各器件的耐受值,做到量化设计,保证防护的可靠性.     

汽车电子技术的现状与展望

简述汽车电子技术应用的分类,总结其特点与要求,并概述我国汽车电子产业的现状．展望汽车电子技术的发展趋势。     

Virtual durability test rigs for automotive engineering

In recent years so-called ‘virtual test rigs’ have become more and more important in the development process of cars and trucks. Originally, the idea was to substitute expensive durability tests with computer simulation. Meanwhile, the focus has changed towards a more cooperative usage of numerical and laboratory rig simulation. For many safety critical issues laboratory tests remain indispensable. In early development stages, when no physical prototypes are available yet, numerical simulation is used to analyse and optimise the design. In this paper, we show how to build numerical simulation models of complex servo-hydraulic test systems and their test specimen using multi-body simulation for the mechanics in combination with simulation models for the hydraulics and controls. We illustrate this at two industrial application examples: a spindle-coupled passenger car suspension rig and a tyre-coupled full vehicle rig. We show how the simulation models are used to design and optimise better test rigs and to support the test rig operation by preparing the physical tests with new specimen, i.e. by performing numerical simulations including numerical drive file iteration before the physical tests start.     

域市轨道交通发展模式研究

城市的发展和规模与城市交通的不断完善、交通技术水平的不断提高有着直接的关系．本文在分析国内外特大城市地域结构变化特征及发展趋势的基础上，提出我国大城市轨道交通发展的基本模式．在特大城市中心区应重点发展地下铁道．在运量达不到地下铁道标准时应发展轻轨交通，而在近郊、卫星城镇和城市带内应尽快发展城市市郊快速铁道．