全文获取类型
收费全文 | 725篇 |
免费 | 30篇 |
专业分类
公路运输 | 77篇 |
综合类 | 306篇 |
水路运输 | 128篇 |
铁路运输 | 67篇 |
综合运输 | 177篇 |
出版年
2024年 | 1篇 |
2023年 | 2篇 |
2022年 | 11篇 |
2021年 | 19篇 |
2020年 | 10篇 |
2019年 | 13篇 |
2018年 | 24篇 |
2017年 | 29篇 |
2016年 | 32篇 |
2015年 | 46篇 |
2014年 | 46篇 |
2013年 | 101篇 |
2012年 | 35篇 |
2011年 | 43篇 |
2010年 | 35篇 |
2009年 | 47篇 |
2008年 | 64篇 |
2007年 | 52篇 |
2006年 | 45篇 |
2005年 | 27篇 |
2004年 | 16篇 |
2003年 | 13篇 |
2002年 | 7篇 |
2001年 | 9篇 |
2000年 | 5篇 |
1999年 | 4篇 |
1997年 | 4篇 |
1996年 | 4篇 |
1994年 | 1篇 |
1993年 | 4篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1989年 | 3篇 |
1985年 | 1篇 |
排序方式: 共有755条查询结果,搜索用时 31 毫秒
671.
Ancor Suárez-Alemán Tomás Serebrisky Oscar Ponce De León 《Maritime Policy and Management》2018,45(5):665-683
Appropriate port regulation and competitive forces tend to be related to higher levels of operational and economic performance of ports. From a policy-making perspective, pursuing efficiency and securing competition in ports to reach a level playing field is a two-step process requiring (1) ex-ante regulations to set the rules that maximize the competition for the market, especially when the policy objective is to attract private operations to ports on competitive concession processes and (2) ex-post competition policy to monitor and preserve competition in the market. This paper studies port regulation in Latin America and the Caribbean (LAC) from a competition perspective, analyzing both ex-ante and ex-post policies implemented in the region. The analysis reveals that the competitive environment in LAC is low, giving room for possible anticompetitive practices in the LAC port sector. Since the end of the 1990s, approximately 80% of container terminals in the region were granted to only five companies. Chile and Mexico have been found to be the best practices in the region, with better conditions assuring robust competition in the market. The main policy implication from this analysis is the need for a stronger involvement of antitrust agencies throughout the port concession processes. 相似文献
672.
Emission governance of air pollutants from ships is a common challenge for the world's shipping industry. Under the framework of the International Maritime Organization (IMO), Europe, North America, and other developed regions and countries have established strict ship Emission Control Areas (ECAs). With some of the largest ports in the world, China suffers severe air pollution from ships, posing a threat to the air quality and public health of the coastal cities. To strengthen the control and supervision over air pollutants, such as ship-emitted sulfur oxides (SOx) in coastal areas, China issued a Sulfur Emission Control Area (SECA) policy for ships in January 2016. However, the new SECA policy lags far behind IMO's existing ECA policies, and continues to face many challenges during implementation. This paper outlines the main framework of China's ship SECA policy, analyzes the legal governance basis, discusses major potential challenges for implementing the policy, and puts forward suggestions for future governance. This research aims to promote the effectiveness of China's sulfur emission-reducing SECA policy by putting forth novel ideas for policymakers and stakeholders. 相似文献
673.
Over the past 30 years, there have been growing concerns on the environmental impacts of maritime transportation, which have attracted great attention from both academia and practitioners. Understanding developments in this area can help guide future research. We conducted a comprehensive review of green shipping research, comprising 213 papers published in transportation journals in SSCI of 2017 over the period 1988–2017. We find that research on green shipping has increased greatly since 2012, accounting for 77.5% of the reviewed papers. The main focus today on green shipping was on air pollution, and the classification of green shipping practice, such as technical measures, operational options, market-based measures, and recycling and reusing, is becoming clear. According to the existing studies, future research on green shipping must strengthen technology research to not only solve practical problems, but also to establish a theoretical green shipping system. Moreover, researchers from different countries could cooperate with each other to give effective suggestions on setting standards and laws of green shipping. Finally, we identify the future research themes will focus on setting up green shipping system and legislation and policy. 相似文献
674.
Zhi Heng 《Maritime Policy and Management》2018,45(1):125-139
This article discusses the proposed Kra Canal and its impacts on the tanker market from an economic perspective. We forecast tanker size distributions and further analyze the impacts of toll structures on tanker traffic. The forecast for tanker size distributions is based on distance savings for tankers as potential users of the Kra Canal. The database covers 105 busiest oil transport routes through the Strait of Malacca for the three-year period 2013–2015. Forecasts for individual routes are achieved using an autoregressive model. Two toll polices, namely the willingness-to-pay policy and the differential-pricing policy, are analyzed in order to maximize the annual toll income of the Kra Canal. The findings for the proposed Kra Canal will attract large vessels from the Strait of Malacca. An interesting finding is that the Kra Canal becomes more profitable during an unfavorable tanker market situation when the time-charter rate is low and fuel price is high. The article concludes with a policy that satisfies the goals of canal operator and government. 相似文献
675.
Reduced private car use can limit greenhouse gas emissions and improve public health. It is unclear, however, how promotion of alternative transport choices can be optimised. A systematic review and meta-analysis was conducted to identify potentially modifiable cognitive mechanisms that have been related to car use and use of alternative transport modes. A qualitative synthesis of measures of potentially modifiable mechanisms based on 43 studies yielded 26 conceptually distinct mechanism categories. Meta-analyses of associations between these mechanisms and car use/non-use generated 205 effects sizes (Pearson’s r) from 35 studies. The strongest correlates of car use were intentions, perceived behavioural control, attitudes and habit. The strongest correlates of alternative transportation choices were intentions, perceived behavioural control and attitudes. Implications for researchers and policy implementation are discussed. 相似文献
676.
体验伦敦公共交通系统 总被引:1,自引:0,他引:1
从旅客、业内人士和决策者的不同角度出发,给不太熟悉伦敦但却对其高效的公共交通系统感兴趣的读者,描述了今日伦敦公共交通系统的主要特征和运作方式.伦敦公共交通融合了公共汽车、地铁、轻轨、有轨电车和通勤火车在内的多种交通方式.良好的交通信息、车辆换乘及一票制的使用是该系统的3个主要特征,以此达到旅客的便捷出行.同时指出,伦敦公共交通系统成功在于3个关键因素:一体化的交通政策和规划、由伦敦市长直接领导的统一交通机构(伦敦交通署)负责机制以及充足的资金保障. 相似文献
677.
Daniel Albalate 《Transportation Research Part A: Policy and Practice》2012,46(2):337-347
Speed limits had been centralized at the federal level since 1974, until decisions were devolved to the states in 1995. However, the centralization debate has reemerged in recent years. This paper conducts the first econometric analysis of the determinants of speed limit laws and State reactions after the repeal. By using mobility, geographic and political variables, our results suggest that geography - which reflects private mobility needs and social preferences -, is one of the main factors influencing speed limit laws, together with political ideology. Furthermore, we identify the presence of regional and time diffusion effects. By presenting first evidence on policy determinants, we provide a better understanding of the formulation of the heterogeneity of speed limits in US and offer implications for the debate on centralization and decentralization of transport policy. 相似文献
678.
Rachael Nealer H. Scott MatthewsChris Hendrickson 《Transportation Research Part A: Policy and Practice》2012,46(3):588-601
This paper estimates the total embodied energy and emissions modal freight requirements across the supply chain for each of over 400 sectors using Bureau of Transportation Statistics Commodity Flow Survey data and Bureau of Economic Analysis economic input-output tables for 2002. Across all sectors, direct domestic truck and rail transportation are similar in magnitude for embodied freight transportation of goods and services in terms of ton-km. However, the sectors differ significantly in energy consumption, greenhouse gas emissions, and costs per ton-km. Recent pressure to reduce energy consumption and emissions has motivated a search for more efficient freight mode choices. One solution would be to shift freight transportation away from modes that require more energy and emit more (e.g., truck) to modes that consume and emit less (e.g., rail and water).Our results show there are no individual sectors for which targeting changes would significantly decrease the total freight transportation energy and emissions, therefore we have also looked at the prospect of policies encouraging many sectors to shift modes. There are four scenarios analyzed: (1) shifting all truck to rail, shifting top 20% sector mode choice, (2) based on their emissions, (3) based on a multi-attribute analysis, and (4) increasing truck efficiency (e.g., mpg). Increasing truck efficiency by 10% results in similar energy and emissions reductions (approximately 7% for energy and 6% for emissions) as targeting the top 20% of sectors when selected based on emissions, whereas selecting the top 20% based on availability to shift from truck results in slightly less reductions of energy and emissions. Implementing policies to encourage higher efficiency in freight trucks may be a sufficient short term goal while efforts to reduce truck freight transportation through sectoral policies are implemented in the long term. 相似文献
679.
Stefan Tscharaktschiew 《Transportation Research Part A: Policy and Practice》2012,46(2):285-309
In many countries passenger transport is significantly subsidized in a variety of ways for various reasons. The objective of this paper is to examine efficiency, distributional, environmental (CO2 emissions) and spatial effects of increasing different kinds of passenger transport subsidies discriminating between household types, travel purposes and travel modes. The effects are calculated by applying a numerical spatial general equilibrium approach calibrated to an average German metropolitan area. In extension to most studies focusing on only one kind of subsidy, we compare the effects of different transport subsidies within the same unified framework that allows to account for two features not yet considered simultaneously in studies on transport subsidies: endogenous labor supply and location decisions. Furthermore, congestion, travel mode choice, travel related CO2 emissions and institutional details regarding the tax system in Germany are taken into account. The results suggest that optimal subsidy levels are either small or even zero. While subsidizing public transport is welfare enhancing, subsidies to urban road traffic reduce aggregate urban welfare. Concerning the latter it is shown that making investments in urban road infrastructure capacity or reducing gasoline taxes may even be harmful to residents using predominantly automobile. In contrast, pure commuting subsidies hardly affect aggregate urban welfare, but distributional effects are substantial. All policies cause suburbanization of city residents and (except for subsidizing public transport) contribute to urban sprawl by raising the spatial imbalance of residences and jobs but the effect is relatively small. In addition, the policies induce a very differentiated pattern regarding distributional effects, benefits of landowners and environmental effects. 相似文献
680.
This paper presents a joint trivariate discrete-continuous-continuous model for commuters’ mode choice, work start time and work duration. The model is designed to capture correlations among random components influencing these decisions. For empirical investigation, the model is estimated using a data set collected in the Greater Toronto Area (GTA) in 2001. Considering the fact that work duration involves medium- to long-term decision making compared to short-term activity scheduling decisions, work duration is considered endogenous to work start time decisions. The empirical model reveals many behavioral details of commuters’ mode choice, work start time and duration decisions. The primary objective of the model is to predict workers’ work schedules according to mode choice, which is considered a skeletal activity schedule in activity-based travel demand models. However, the empirical model reveals many behavioral details of workers’ mode choices and work scheduling. Independent application of the model for travel demand management policy evaluations is also promising, as it provides better value in terms of travel time estimates. 相似文献