全文获取类型
| 收费全文 | 442篇 |
| 免费 | 3篇 |
专业分类
| 公路运输 | 83篇 |
| 综合类 | 65篇 |
| 水路运输 | 55篇 |
| 铁路运输 | 98篇 |
| 综合运输 | 144篇 |
出版年
| 2025年 | 1篇 |
| 2022年 | 2篇 |
| 2021年 | 5篇 |
| 2020年 | 29篇 |
| 2019年 | 7篇 |
| 2018年 | 13篇 |
| 2017年 | 15篇 |
| 2016年 | 23篇 |
| 2015年 | 26篇 |
| 2014年 | 12篇 |
| 2013年 | 36篇 |
| 2012年 | 29篇 |
| 2011年 | 46篇 |
| 2010年 | 39篇 |
| 2009年 | 40篇 |
| 2008年 | 46篇 |
| 2007年 | 31篇 |
| 2006年 | 20篇 |
| 2005年 | 8篇 |
| 2004年 | 6篇 |
| 2003年 | 4篇 |
| 2001年 | 3篇 |
| 2000年 | 1篇 |
| 1997年 | 2篇 |
| 1996年 | 1篇 |
排序方式： 共有445条查询结果，搜索用时 15 毫秒
101.
随着城市轨道交通网络化进程的不断推进,线路运输能力和客流不协调的问题日益凸显,从信号系统角度出发,提出了一种高效、经济且自动化的城市轨道交通线路运输能力评估和方案验证方法,可以较快地找出运输能力瓶颈,辅助给出提高运输能力的解决方案,并可对解决方案进行快速验证评估。 相似文献
102.
A. D. Pearman 《运输规划与技术》2013,36(1):73-85
This paper argues that the types of uncertainty having the most serious consequences for transport planning are not captured by existing modelling procedures, which typically rely on a limited amount of sensitivity testing of plans based on extrapolative forecasts. It recommends as an alternative scenario‐based planning, an approach which is finding increasing application in private sector policy formation. The paper summarises the origins of scenario planning and the gradual broadening in its range of application, before going on to suggest methods of scenario construction suitable for transport planning applications. It considers the arguments for and against associating probabilities with scenarios and also addresses the problems of formulating transport strategies and evaluating them within the context of a scenario‐based approach to strategy choice. 相似文献
103.
Public institutions and private companies all around the world agree that road transport is one of the main sectors responsible for global warming. With this in mind, all of them have designed actions to increase efficiency and reduce fuel consumption and emissions. A favorite for the companies is eco-driving because it can improve the fleet performance without a great investment. However, although these programs have achieved promising results in the majority of the experiences, the figures are not so encouraging in the long term. In many cases this decrease is produced by fuzzy reward programs or the total lack of them. Nevertheless, any coherent reward program, in order to be effective, must be associated with a complete and fair evaluation process which takes into account all the different aspects and complexities related with driving. In this paper, we propose a formal characterization of an efficient driving evaluation process which starts with a review of many different driving recommendation systems. These recommendations are used as seeds to build a set of formal competences that any eco driver must have, as well as the learning outcomes associated with each competence. A set of patterns of driving behaviors are defined, that allow confirming any of the learning outcomes. The definition also comprises a set of Key Performance Indicators (KPIs) for each learning outcome. These KPIs allow measuring the progress associated with each competence. Finally, we also propose some relevant differences that must be taken into account for the goals associated with each KPI, depending on the domain of application: type and road geometry, vehicle type (automatic or manual, passengers, cargo or not, public or private), amount of traffic, weather. Some examples of this driver characterization have been included to demonstrate the process. 相似文献
104.
Sub-Saharan Africa has recently undergone, or still do in many countries, a period of transport infrastructure expansion. Current policies are centred on the development of international links, which require large capital-intensive projects and are sometimes economically dubious. This paper reviews the past policies and transport functions since colonial times by placing them in their economic and political context. We find that present strategies have similarities to the ones prevailing in previous periods, where expansion phases dominated by transport-led economic growth theories were followed by a stagnation of Africa’s infrastructure development. In view of the challenges in translating findings from empirical research into right policies, we identify the potential of more balanced and sustainable strategic investments, notably by reinforcing the existing secondary transport networks converging into urban centres. 相似文献
105.
In this paper we examine how 23 industrialised countries treat wider economic impacts (WEIs) in transport appraisals. We identify 12 different types of impacts based on these countries’ appraisal guidelines. Agglomeration impacts and Production changes in imperfect markets are the most widely accepted, being recognised by 14 and 10 countries, respectively. However, about half of the impacts are mentioned by only one country, and few recommend including the impacts directly in cost–benefit analyses. Several countries provide provisos or criteria that must be met before WEIs can be assessed in the first place. We found method recommendations for quantifying WEIs in 10 countries. However, with the exception of the UK Department for Transport’s (DfT) methodological framework, there is very little international consensus on the choice of appropriate methods. Our findings thus supplement and reinforce the conclusions from the Norwegian Official Report of the Hagen Committee [NOU 2012:16. (2012). Samfunnsøkonomiske analyser. Oslo: Departementenes servicesenter] that there is currently no established consensus on the magnitude and relevance of WEIs, or on how and which of these impacts should be taken into account in transport appraisals. Recommendations for further research and appraisal practices are provided. 相似文献
106.
In the area of active traffic management, new technologies provide opportunities to improve the use of current infrastructure. Vehicles equipped with in-car communication systems are capable of exchanging messages with the infrastructure and other vehicles. This new capability offers many opportunities for traffic management. This paper presents a novel merging assistant strategy that exploits the communication capabilities of intelligent vehicles. The proposed control requires the cooperation of equipped vehicles on the main carriageway in order to create merging gaps for on-ramp vehicles released by a traffic light. The aim is to reduce disruptions to the traffic flow created by the merging vehicles. This paper focuses on the analytical formulation of the control algorithm, and the traffic flow theories used to define the strategy. The dynamics of the gap formation derived from theoretical considerations are validated using a microscopic simulation. The validation indicates that the control strategy mostly developed from macroscopic theory well approximates microscopic traffic behaviour. The results present encouraging capabilities of the system. The size and frequency of the gaps created on the main carriageway, and the space and time required for their creation are compatible with a real deployment of the system. Finally, we summarise the results of a previous study showing that the proposed merging strategy reduces the occurrence of congestion and the number of late-merging vehicles. This innovative control strategy shows the potential of using intelligent vehicles for facilitating the merging manoeuvre through use of emerging communications technologies. 相似文献
107.
Aviation is a fast growing sector with increasing environmental concerns linked to aircraft emissions at airports and noise nuisance. This paper investigates the factors affecting the annual environmental effects produced by a national aviation system. The environmental effects are computed using certification data for each aircraft-engine combination. Moreover, we also take into account for the amount of environmental effects that is internalized at the airport, mainly through noise regulation. We study a dataset covering information on Italian airports during the period 1999–2008. We show that a 1% increase in airport’s yearly movements yields a 1.05% increase in environmental effects, a 1% in aircraft size (measured in MTOW) gives rise to a 1.8% increase and a 1% increase in aircraft age generates a 0.69% increase in environmental effects. Similar results but with smaller magnitudes are observed if airport internalization is considered. Our policy implications are that the tariff internalizing the total amount of externality is about euro 180 per flight, while the tariff limiting only pollution is about euro 60 and the one reducing noise is about euro 110. Moreover, our airport examples show that managers should prefer to address additional capacity by increasing frequency rather than aircraft size, since the former strategy is more environmental friendly. 相似文献
108.
Transport sector restructuring to achieve deep GHG emission cuts has attracted much attention because transportation is important for the economy and inflexible in greenhouse gas emission reduction. The aim of this paper is to simulate transition towards low carbon transportation in the European Union until 2050 and to assess the ensuing macroeconomic and sectorial impacts. Transport restructuring is dynamically simulated using a new transport-oriented version of the computable general equilibrium model GEM-E3 which is linked with the PRIMES-TREMOVE energy and transport sectors model. The analysis draws from comparing a reference scenario projection for the EU member-states up to 2050 to alternative transport policy scenarios and sensitivities which involve deep cutting of CO2 emissions. The simulations show that transport restructuring affects the economy through multiple channels, including investment in infrastructure, the purchasing and manufacturing of new technology vehicles, the production of alternative fuels, such as biofuels and electricity. The analysis identifies positive impacts of industrial activity and other sectors stemming from these activities. However, the implied costs of freight and passenger transportation are of crucial importance for the net impact on GDP and income. Should the transport sector transformation imply high unit costs of transport services, crowding out effects in the economy can offset the benefits. This implies that the technology and productivity progress assumptions can be decisive for the sign of GDP impacts. A robust conclusion is that the transport sector decarbonisation, is likely to have only small negative impacts on the EU GDP compared to business as usual. 相似文献
109.
Transport networks underpin economic activity by enabling the movement of goods and people. During extreme weather events transport infrastructure can be directly or indirectly damaged, posing a threat to human safety, and causing significant disruption and associated economic and social impacts. Flooding, especially as a result of intense precipitation, is the predominant cause of weather-related disruption to the transport sector. Existing approaches to assess the disruptive impact of flooding on road transport fail to capture the interactions between floodwater and the transport system, typically assuming a road is fully operational or fully blocked, which is not supported by observations. In this paper we develop a relationship between depth of standing water and vehicle speed. The function that describes this relationship has been constructed by fitting a curve to video analysis supplemented by a range of quantitative data that has be extracted from existing studies and other safety literature. The proposed relationship is a good fit to the observed data, with an R-squared of 0.95. The significance of this work is that it is simple to incorporate our function into existing transport models to produce better estimates of flood induced delays and we demonstrate this with an example from the 28th June 2012 flood in Newcastle upon Tyne, UK. 相似文献
110.
The interdependence and complexity of socio-technical systems and availability of a wide variety of policy measures to address policy problems make the process of policy formulation difficult. In order to formulate sustainable and efficient transport policies, development of new tools and techniques is necessary. One of the approaches gaining ground is policy packaging, which shifts focus from implementation of individual policy measures to implementation of combinations of measures with the aim of increasing efficiency and effectiveness of policy interventions by increasing synergies and reducing potential contradictions among policy measures. In this paper, we describe the development of a virtual environment for the exploration and analysis of different configurations of policy measures in order to build policy packages. By developing systematic approaches it is possible to examine more alternatives at a greater depth, decrease the time required for the overall analysis, provide real-time assessment and feedback on the effect of changes in the configurations, and ultimately form more effective policies. The results from this research demonstrate the usefulness of computational approaches in addressing the complexity inherent in the formulation of policy packages. This new approach has been applied to the formulation of policies to advance sustainable transportation. 相似文献