首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   271篇
  免费   3篇
公路运输   29篇
综合类   7篇
水路运输   89篇
铁路运输   3篇
综合运输   146篇
  2022年   3篇
  2021年   2篇
  2020年   8篇
  2019年   7篇
  2018年   8篇
  2017年   10篇
  2016年   12篇
  2015年   3篇
  2014年   8篇
  2013年   65篇
  2012年   8篇
  2011年   16篇
  2010年   20篇
  2009年   11篇
  2008年   11篇
  2007年   7篇
  2006年   4篇
  2005年   4篇
  2004年   1篇
  2003年   9篇
  2002年   9篇
  2001年   3篇
  2000年   5篇
  1999年   1篇
  1998年   3篇
  1997年   2篇
  1996年   4篇
  1995年   1篇
  1994年   1篇
  1993年   4篇
  1991年   1篇
  1990年   1篇
  1989年   1篇
  1988年   2篇
  1987年   3篇
  1986年   1篇
  1985年   1篇
  1983年   3篇
  1982年   2篇
  1981年   2篇
  1980年   1篇
  1979年   1篇
  1978年   1篇
  1975年   3篇
  1974年   1篇
排序方式: 共有274条查询结果,搜索用时 296 毫秒
101.
This first part of the state-of-the art focuses on the origins of road safety modeling, covering data, early models and the public health context of model formulation and use.  相似文献   
102.
The third part of the state-of-the-art focuses on the future of road safety modeling and on conjectures concerning the evolution of national safety indicators. In the absence of econometric developments specific to road safety modeling, the research future must rely on pre-existing statistical procedures of econometrics applied to discrete/count and to aggregate data. In terms of contents, growing interest in the heterogeneity of road accident outcomes by category of victims could lead to treatments of this issue across research streams, say by top-down and bottom-up developments, but this speculation does not rest on extant adequate formulations of the issue of road user class and victim analysis. But understanding the time profile of aggregate national performance indicators is quite another matter.  相似文献   
103.
Stated choice studies have been applied regularly to the valuation of time savings and other attributes of travelling as perceived by individuals. In such experiments, respondents often provide reference levels for the attributes and the hypothetical choices presented to them are pivoted around actual behaviour. However, most individuals are not able to provide reference levels for the number of casualties on the road they travel. Thus, if valuation of this important element is attempted, it is the researcher who must provide casualty risk reference levels to the respondents. Some studies have applied route choice experiments including a safety attribute but the majority has been limited to only one particular road section with a common baseline risk for all respondents.  相似文献   
104.
This paper deals with the importance of port choice and container terminal selection for deep-sea container carriers. The paper focuses on the research question: on what basis do deep-sea container operators select container ports (strategy) and container terminals (financial reasons) in the Hamburg–Le Havre range over others? In answering this research question, three dimensions are addressed in detail: the buying decision characteristics; port choice strategy; and terminal selection. The results show that strategic considerations at company level are important. For port choice the most important criteria from a carrier's perspective are: availability of hinterland connections; reasonable tariffs; and immediacy of consumers (large hinterland). In addition to these criteria, shipping lines attach great value to often neglected factors, such as feeder connectivity, environmental issues and the total portfolio of the port. The study reveals that port selection and terminal selection are not the same with terminal selection criteria mainly depending on: handling speed; handling costs; reliability; and hinterland connections. The analysis also brought forward that the decision making is different per container carrier, per trade and per port type, implying that a one size fits all approach is not relevant.  相似文献   
105.
This paper, using data envelopment analysis, assesses the efficiency of 122 iron ore and coal ports in 2005. Estimates for 54 loading and 68 unloading ports show that the main source of inefficiency in bulk terminals is related to the scale. Results aggregated at a country level demonstrate that the national efficiency can be achieved either through a limited number of large ports or by combining smaller ports with complementary characteristics—national network effect.  相似文献   
106.
Abstract

Cost–benefit analysis (CBA) plays a major role in the ex ante evaluation of rail projects in many western countries. At first sight carrying out a CBA for rail projects seems straightforward, since cost estimates are almost always available, and the most dominant benefits are generally known, being the travel time saved and the increase in consumer surplus due to induced demand. However, the practice is much more complex: the quality of current estimates for costs and benefits is often poor and several benefits-related aspects are ignored. This article gives an overview of the challenges in improving the quality of CBAs for rail projects.  相似文献   
107.
Abstract

The growing popularity of electric devices and the increasing number of hybrid and electric cars have recently raised concerns about the use of auditory signals by vulnerable road users. This paper consolidates current knowledge about the two trends in relation to cycling safety. Both a literature review and a crash data analysis were carried out. Based on a proposed conceptual model, knowledge gaps are identified that need to be addressed for a better understanding of the relation between limitations on auditory information while cycling. Results suggest that the concerns regarding the use of electronic devices while cycling and the advent of hybrid and electric vehicles are justified. Listening to music and conversing on the phone negatively influence cyclists’ auditory perception, self-reported crash risk and cycling performance. With regard to electric cars, a recurring problem is their quietness at low speeds. Implications of these findings in terms of cycling safety are discussed.  相似文献   
108.
沥青混合料烟雾与材料力学性能之间的关系   总被引:1,自引:0,他引:1  
着重于研究热拌沥青混合料生产过程中产生的烟雾与沥青力学性能之间的关系,涉及的影响因素有温度、沥青种类以及一些动力学参数。研究者在试验室拌和机上安装了气体取样设备,能够在正常拌和的同时对热拌沥青混合料烟雾中的多环芳香烃(PAH)以及有机化合物(TOC)进行取样分析。通过对沥青材料进行室内性能指标的测试,发现在所有指标中回收沥青的复合模量与沥青烟雾排放量的相关性最好,因为它的结果同时反映了材料的物理性能以及沥青氧化和老化的程度。同时还建立了热拌沥青混合料烟雾排放与拌和参数以及混合料力学性能之间的关系。  相似文献   
109.
企业核心能力理论发展评述   总被引:5,自引:0,他引:5  
企业核心能力理论是当今世界管理学和经济学交互融合的最新理论成果之一。长期以来理论界和工商实践一直在寻求企业持续竞争优势的奥秘。企业核心能力理论则揭示了在企业表象及所处环境之外的能使企业获得优势的内在特质。本论述了企业核心能力理论的发展历程、形成背景、时代特征和主要论点。  相似文献   
110.
This paper presents a number of reasons that are responsible for the disappointment of authorities in their operators’ efforts to develop public transport (PT) to the advantage of their travellers. The lessons drawn in this paper are based upon the competitive tendering experience of the authors and upon the results of meetings organised with parties involved in competitive tendering and aimed at exchanging lessons. There appears to be three main causes: (1) there is freedom for the operator, but the contract is bad; (2) there is freedom for the operator, there is a good contract, but there is no market; and (3) there is freedom for the operator, but the operator is not able to use it. The paper concludes with a few perspectives for improvement.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号