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"超限超载"的产生与发展,蕴藏着深层的内在运作机理,包含着复杂的经济社会原因.其中道路货物运输价格体系的长期扭曲失衡与成本结构的有欠合理是一个不容忽视的根本原因.为此,公路所开展了货运市场运价与成本"治超"专项研究,先后历时一个多月,行程数千公里,深入7省市运输一线,对21家典型企业和个体业户的23辆货车、24条线路进行了跟踪调查,获取了大量的第一手资料与原始数据,并对此进行了解析. 相似文献
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Ngila Mwase† 《运输评论》2013,33(3):191-206
Zambia has attempted to reduce her excessive transport dependency on her traditional transport routes via South Africa and the former Portugese colonies. The costly construction of the Tanzania‐Zambia Railway (TAZARA) was part of this diversification strategy. This article examines the nature, extent and direction of Zambian traffic, including its historical evolution. It explores further the place of TAZARA among the various routes to Mozambican, Angolan and South African ports, and the ensuing actual and potential competition. Future traffic patterns will be influenced not only by the direct and service‐oriented costs of the different lines, but also by the region's volatile and uncertain political climate. 相似文献
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针对海中箱梁现浇施工中的工程量大、工期紧迫、悬臂法施工不能满足工期要求和施工难度大等问题,文章结合青岛海湾大桥箱梁现浇施工实践,介绍以钢管桩支撑作为承载基础,采用贝雷梁与碗扣式支架相结合的支架,成功地解决现浇箱梁施工难题的方法。 相似文献
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Robert E. Paaswell 《Transportation》1973,2(4):351-371
An examination of current population statistics shows that in the U.S. more than half of the population is without immediate access to a car, and in the U.K. more than three-fifths of the population is without access to a car. This phenomenon has been accentuated by national investment in both countries in major highway programs. The term carless refers to more than just households that own no cars. It extends, in households with cars to those without licenses (old and young), the handicapped, and even the licensed drivers who have no access to the family car when it is in use elsewhere (e.g. at work). The most severely effected are those in urban areas and especially the urban poor. Transportation expenses are limited for the poor when other family expenditures (food, shelter) take a high priority. Once the work trip has been satisfied, money for other trips, for the poor, is not always available. One solution to cost-free travel is pedestrianism (walking), but this too is difficult in urban areas where the pedestrian has been overlooked in favor of the car. Solutions to problems of the carless include dial-a-ride, better public transit, and better design of urban form. 相似文献
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章简略地分析了单线循环固定抱索器索道抱索器移位及索道频繁开停车对索道运载索、驱动机减速器、制动器等部件使用寿命的影响,并提出了相应的减轻这些影响的技术对策。 相似文献
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Mark Greer 《Transportation Research Part A: Policy and Practice》2009,43(9-10):779-789
Data envelopment analysis is used to evaluate the technical efficiencies of a number of major passenger airlines in the United States at transforming their inputs (labor, fuel and fleet-wide seating capacity) into available seat-miles. A tobit regression model is then used to identify the underlying drivers of airline efficiency, as measured by the data envelopment analysis efficiency score. The impact of unionization on airline efficiency is found to be statistically insignificant, controlling for the influences of other hypothesized determinants of airline efficiency: the average age of an airline’s fleet, the average size of its aircraft, its average stage length, the extent to which the airline relies of hubbing within its route structure, the percent of its passenger enplanements that are international, and whether the airline is a legacy carrier. The statistically significant drivers of airline efficiency, at a ten percent level of significance, are average aircraft size, average stage length and the extent to which the airline relies on hubbing and connecting flights within its route structure. The stage length variable is not significant at a five percent level of significance, however. An increase in average aircraft size or in average stage length enhances an airline’s efficiency whereas an increase in hubbing reduces it. 相似文献
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平顶山汽车运输总公司(简称"总公司")历来重视安全生产,把安全生产工作作为一项长期的重要工作,常抓不懈,始终贯彻"安全第一,预防为主"的方针,坚持"先安全后生产,不安全不生产"的原则.近年来公司安全形势一直处于良好状态,2005年春运及"五一"黄金周期间没有发生重大以上安全责任事故. 相似文献
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Tony H. Grubesic Fangwu Wei 《Transportation Research Part A: Policy and Practice》2012,46(10):1562-1573
Essential Air Service (EAS) is a federally funded program in the United States that provides connecting, commercial air service between rural communities and their nearest large or medium commercial hub airport. During fiscal year 2010, $170 million dollars were spent to provide this service to 107 communities in the US. However, with significant variations in subsidies to each airport (ranging from $427,757 to $3,082,403) and marked differences in passengers served, there are serious concerns regarding the overall efficiency of the EAS program. The purpose of this paper is to use data envelopment analysis integrated in a geographic information system for evaluating service efficiencies at the community level. Policy implications and strategies to improve the EAS program are discussed. 相似文献
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复合式TBM在重庆地铁实践中的关键技术研究 总被引:4,自引:0,他引:4
文章通过复合式TBM在重庆轨道交通六号线工程中的应用实践,对复合式TBM的特点及其工程适应性进行了分析;对衬砌断面及其支护参数的设计、超深竖井及其支护参数的设计,以及复合式TBM穿越建筑物的施工微扰动控制设计等几大关键技术方案进行了详细阐述;明确了设计方案的合理性与先进性. 相似文献
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新老路基结合部处治技术 总被引:3,自引:0,他引:3
新老路基结合部处治技术课题组 《西部交通科技》2006,(4)
文章分析了路基拓宽工程的主要方式和工程技术问题,提出了新老路基不协调变形的计算方法和路面结构对路基不协调变形的力学响应模式,通过建立基于不协调变形控制的路基拓宽设计理论和方法,系统地提出不同条件下的新老路基结合部处治技术及其施工控制方法,为公路路基拓宽工程的设计与施工提供了科学依据。 相似文献
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为了满足汽车性能主观评价的实车试验,必须对汽车试验场有所要求.通过对国内外汽车试验场进行比较,得出主观评价试验场地的独特需求有:动态试验广场、操纵性试验道路和转向圆广场. 相似文献