全文获取类型
收费全文 | 227篇 |
免费 | 3篇 |
专业分类
公路运输 | 45篇 |
综合类 | 34篇 |
水路运输 | 75篇 |
铁路运输 | 28篇 |
综合运输 | 48篇 |
出版年
2023年 | 2篇 |
2022年 | 8篇 |
2021年 | 6篇 |
2019年 | 5篇 |
2018年 | 6篇 |
2017年 | 6篇 |
2016年 | 7篇 |
2015年 | 2篇 |
2014年 | 6篇 |
2013年 | 27篇 |
2012年 | 7篇 |
2011年 | 8篇 |
2010年 | 7篇 |
2009年 | 10篇 |
2008年 | 4篇 |
2007年 | 8篇 |
2006年 | 11篇 |
2005年 | 9篇 |
2004年 | 5篇 |
2003年 | 12篇 |
2002年 | 20篇 |
2001年 | 19篇 |
2000年 | 6篇 |
1999年 | 9篇 |
1998年 | 4篇 |
1995年 | 1篇 |
1994年 | 3篇 |
1991年 | 1篇 |
1989年 | 3篇 |
1988年 | 2篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1977年 | 1篇 |
1974年 | 1篇 |
排序方式: 共有230条查询结果,搜索用时 156 毫秒
91.
Rail-road crossings generate a range of transport, economic, social and environmental impacts. While much research has focused on selected impacts such as safety, little consideration has been given to wider impacts. The aim of this research was to therefore develop a holistic understanding of the impacts of rail-road crossings (both at-grade and grade-separated) and to identify key gaps in knowledge in this field. An international synthesis of rail-road crossing impacts was developed through a detailed literature review, which revealed a total of 18 different types of impacts associated with rail-road crossings. The review found that most research to date has focused on quantifying transport and economic impacts, particularly safety and road vehicle delay, with little consideration given to social and environmental impacts. A number of research gaps have been identified which provide a clear agenda for future research. These gaps include the use of empirical evidence to support impact assessments, and the need to better understand the impacts of grade-separating rail-road crossings in terms of safety, travel time variability, land use, traffic flow, rail vehicle delay, disability access, and crime. 相似文献
92.
A travel plan is a mechanism for delivering a package of transport measures at a site to manage car use and encourage the use of more sustainable forms of transport. In recent years, travel plans have been required for new infill and greenfield developments through the land-use planning and approvals process, predominantly in the United Kingdom, the United States, continental Europe and Australia. This paper contributes to the literature by providing a global review of travel plans for new developments. The results show that while travel plans for new developments share a common set of elements with those for pre-existing sites, differences within each element are notable, particularly in the types of travel plan measures adopted, processes for managing the travel plan, and approaches to monitoring and review. Results of previous evaluations have varied considerably, although most have reported a reduction in car driver trips of 10–20 percentage points. Despite this, most evaluations lack rigour, with a paucity of robust evidence. Key success factors identified by the literature, such as the provision of an explicit policy supporting the role of travel plans, should be embedded within the travel planning process where possible to ensure best outcomes for new developments. 相似文献
93.
论文将锥头射弹侵彻贯穿金属薄靶板的耗能分为整体和局部耗能两部分。基于空腔膨胀理论,给出了靶板对射弹的阻力表达式,然后计算出局部变形耗能。根据量纲分析和相似原理,由搜集到的弹道试验数据拟合求得整体变形耗能,推出了射弹穿透金属靶板的弹道极限公式。并将模型预测结果和数值仿真分析的结果进行了比较分析。 相似文献
94.
The two main value propositions in international container transport are ‘port-to-port’ services and ‘door-to-door’ services. In port-to-port services, buyers ‘just’ purchase maritime transport from a shipping line. Door-to-door services comprise the total transport chain and include land-based transport. Carriers as well as forwarders offer these door-to-door services. In this paper we provide a qualitative assessment of an emerging third value proposition that is centred around inland terminals (ILTs). Such a value proposition consists of transport up to the ILT, and may have advantages over port-to-port services, such as better leverage of scale economies, better repositioning of empty containers and better alignment with the business model of forwarders. This paper conceptually and empirically explores such a value proposition. 相似文献
95.
The different types of entry barrier in seaports are analysed and the policies and practices to reduce them are discussed in this paper. In most seaports, economic, regulatory, and geographical entry barriers are substantial and increasing in complexity as ports become embedded in supply chains and multilayered networks with multiple entry-levels. Various entry barriers in seaports are identified through an overview of the relevant literature and their presence is confirmed by empirical data describing them. The case is then made for lowering these barriers. This would be desirable from an economic point of view, since lower barriers strengthen the contestability of markets and increase the level of intra-port competition. The latter might yield substantial benefits, such as fostering specialization and preventing the abuse of market power. Finally, low entry barriers would facilitate the faster implementation of new technologies and business models. In the third part of the analysis, policies and practices designed to reduce entry barriers are examined. The implications are discussed of current national and supranational (EU) policy initiatives aimed to liberalize service provision in seaports. Other (de)regulatory policies that could contribute to the reduction of entry barriers are analysed. 相似文献
96.
José Manuel Vassallo Pablo Pérez De Villar Ramón Muñoz‐Raskin Tomás Serebrisky 《运输评论》2013,33(2):261-278
Abstract Public transport policy in the Madrid Metropolitan Area is often deemed as a success. In 1985, an important reform was carried out in order to create a new administrative authority to coordinate all public transport modes and establish a single fare for all of them. This reform prompted a huge growth in public transport usage, even though it reduced the funding coverage ratio of the transport system. Since then, Madrid’s public transport system has been undergoing an increasing level of subsidization, which might jeopardize the financial viability of the city public transport system in the future. In this paper, we present a detailed analysis of the evolution of the public transport funding policy in Madrid in recent years. We found that the increasing level of subsidy can hardly be explained on the basis of equity issues. Moreover, we claim that there is still room for a funding policy that makes the efficiency of the system compatible with its financial sustainability. 相似文献
97.
Abstract Since 1990s the liner shipping industry has faced a period of restructuring and consolidation, and been confronted with a continuing increase in container vessel scale. The impact of these changes is noticeable in trade patterns, cargo handling methods and shipping routes, in short ‘operations’. After listing factors influencing size, growth in container ship size is explained by economies of scale in deploying larger vessels. In order to quantify economies of scale, this paper uses the liner service cash flow model. A novelty in the model is the inclusion of +6000-20-foot Equivalent Unit (TEU) vessels and the distinction in costs between single and twin propeller units on ships. The results illustrate that scale economies have been – and will continue to be – the driving force behind the deployment of larger container vessels. The paper then assesses the link between ship size and operations, given current discussions about the increase in container vessel scale. It is found that (a) ship size and operations are linked; (b) optimal ship size depends on transport segment (deep-sea vs. short-sea shipping, SSS), terminal type (transhipment terminals vs. other terminals), trade lane (East-West vs. North-South trades) and technology; and (c) a ship optimal for one trade can be suboptimal for another. 相似文献
98.
为研究钢丝绳聚氨酯水泥复合材料加固损伤空心板梁的力学性能,进行加固条件下损伤空心板梁抗弯性能模型试验,分析板梁挠度、裂缝宽度和承载能力变化规律,研究复合材料加固损伤空心板梁的破坏机理.试验结果表明:采用钢丝绳聚氨酯水泥复合材料加固经过预压的损伤空心板梁,其破坏过程分为钢丝绳断裂、复合材料开裂和整体结构受弯破坏3个阶段,属于适筋梁破坏;此板梁的实测屈服荷载和极限承载力比未加固空心板梁分别提高28.60%、40.00%,相同荷载作用下的挠度降低22.81%,最大裂缝的宽度减小52.73%,梁体延性提高57.14%,梁体的屈服阶段延长,空心板梁的安全性提高.采用钢丝绳聚氨酯水泥复合材料加固损伤空心板梁可显著改善梁体的整体承载性能,提高安全性. 相似文献
99.
The different types of entry barrier in seaports are analysed and the policies and practices to reduce them are discussed in this paper. In most seaports, economic, regulatory, and geographical entry barriers are substantial and increasing in complexity as ports become embedded in supply chains and multilayered networks with multiple entry-levels. Various entry barriers in seaports are identified through an overview of the relevant literature and their presence is confirmed by empirical data describing them. The case is then made for lowering these barriers. This would be desirable from an economic point of view, since lower barriers strengthen the contestability of markets and increase the level of intra-port competition. The latter might yield substantial benefits, such as fostering specialization and preventing the abuse of market power. Finally, low entry barriers would facilitate the faster implementation of new technologies and business models. In the third part of the analysis, policies and practices designed to reduce entry barriers are examined. The implications are discussed of current national and supranational (EU) policy initiatives aimed to liberalize service provision in seaports. Other (de)regulatory policies that could contribute to the reduction of entry barriers are analysed. 相似文献
100.
Olaf Gietelink Jeroen Ploeg Bart De Schutter Michel Verhaegen 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2006,44(7):569-590
This paper presents a new method for the design and validation of advanced driver assistance systems (ADASs). With vehicle hardware-in-the-loop (VEHIL) simulations, the development process, and more specifically the validation phase, of intelligent vehicles is carried out safer, cheaper, and is more manageable. In the VEHIL laboratory, a full-scale ADAS-equipped vehicle is set up in a hardware-in-the-loop simulation environment, where a chassis dynamometer is used to emulate the road interaction and robot vehicles to represent other traffic. In this controlled environment, the performance and dependability of an ADAS is tested to great accuracy and reliability. The working principle and the added value of VEHIL are demonstrated with test results of an adaptive cruise control and a forward collision warning system. On the basis of the 'V' diagram, the position of VEHIL in the development process of ADASs is illustrated. 相似文献