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   1815篇
  免费   25篇
公路运输   610篇
综合类   70篇
水路运输   592篇
铁路运输   66篇
综合运输   502篇
  2023年   14篇
  2022年   43篇
  2021年   14篇
  2020年   13篇
  2019年   18篇
  2018年   68篇
  2017年   44篇
  2016年   60篇
  2015年   13篇
  2014年   73篇
  2013年   278篇
  2012年   85篇
  2011年   105篇
  2010年   86篇
  2009年   92篇
  2008年   91篇
  2007年   49篇
  2006年   32篇
  2005年   41篇
  2004年   29篇
  2003年   25篇
  2002年   31篇
  2001年   27篇
  2000年   24篇
  1999年   24篇
  1998年   38篇
  1997年   30篇
  1996年   40篇
  1995年   28篇
  1994年   13篇
  1993年   16篇
  1992年   25篇
  1991年   16篇
  1990年   19篇
  1989年   13篇
  1987年   12篇
  1986年   10篇
  1985年   14篇
  1984年   13篇
  1983年   13篇
  1982年   12篇
  1981年   19篇
  1980年   15篇
  1979年   22篇
  1978年   10篇
  1977年   19篇
  1976年   18篇
  1975年   16篇
  1974年   11篇
  1973年   9篇
排序方式: 共有1840条查询结果,搜索用时 93 毫秒
501.
Various alternative frameworks are available for modelling urban land‐use–transport interaction. This paper provides a detailed review of six of these frameworks that have been or are currently being used to develop operational models. The intention is to indicate what is the general nature of the current state of practice and what is now available for practical modelling work in the area. The intention is also to compare the current state of practice with what might be the ideal in various respects. The six frameworks reviewed (ITLUP, MEPLAN, TRANUS, MUSSA, NYMTC‐LUM and UrbanSim) are considered in terms of their representations of physical systems, decision‐makers and processes, along with various more general modelling and implementation issues. None matches the ideal as envisaged here in all respects. However, a wide range of policy considerations can be handled explicitly with what is available, and more recent developments show an encouraging trend towards expansion in the scope of what can be considered. Further strengthening of the behavioural basis and relaxation of some of the more restrictive assumptions would appear to be both appropriate and likely in the future.  相似文献   
502.
C. A. Nash 《运输评论》2013,33(3):269-282
This paper compares the major role played by suburban rail (S‐Bahn) systems in West German cities with the much more limited role of rail in the British conurbations. Clearly, the difference owes much to the institutional and financial arrangements in the two countries. In West Germany, large amounts of earmarked funds have been available for rail investment, whilst the Federal government has been willing to shoulder much of the burden of operating subsidies. The Verkehrsverbund has emerged as a highly effective way of coordinating fares and services without direct ownership of any mode of transport. By contrast in Britain funds for rail investment have been much more limited. Progress with integration has been far slower, and is threatened by current government policies regarding both bus deregulation and the abolition of the Metropolitan county councils. Whilst rail is firmly established in German cities, its future in Britain looks bleak.  相似文献   
503.
Recent port reform established major commercial ports as Canadian Port Authorities (CPAs) as federal non-profit, business corporations. Canadian port reform was aimed at allowing CPAs to compete effectively. Canada's major ports operate in an increasingly competitive business environment. To gain advantage over their competition, Canadian ports must develop business strategies dealing with their organizational cultures, institutional structures, operations, and facility provision. Developing appropriate strategies involves creating a strategic plan that considers external and internal port environments. This paper outlines the evolution of strategic planning and its applicability to Canadian ports. The initial literature review is followed by a brief review of Canadian port reform and an analysis of external and internal port environments. This analysis determines the resources available to exploit external opportunities and defend against threats, and considers the internal strengths and weaknesses of Canadian ports. A list of strategic issues facing Canadian ports and how the Canada Marine Act affected them is derived from the analysis.  相似文献   
504.
Abstract

This article argues that using the public sector and the private market in the historically delineated and traditional ways offers only the bluntest of tools with which to approach the complex problem of coastal zone management. It therefore seeks to provide a basis for reformulating our understanding of sectoral responsibility with regard to resources management. First, it conceptually analyzes the relative strengths and weaknesses of the two sectors. Second, it examines three examples of coastal resources management—beaches and shorelands, artificial reefs, and coastal wetlands—in analyzing the complexities of the coastal management challenge and the limitations of our current approaches. Finally, we provide an alternative perspective on how these common property resource allocation decisions can be made.  相似文献   
505.
An engine mapping-based methodology is developed to gain a first approximation of a vehicle’s performance and emissions during a light-duty cycle. The procedure is based on a steady-state experimental investigation of the engine with an appropriate vehicle drivetrain model applied so that the cycle vehicle speed data can be transformed into engine speed and torque. Correction analysis is then applied based on transient experimentation to account for the transient discrepancies during real driving. The developed algorithm is applied for the case of a diesel-engined vehicle running on the European light-duty cycle. A comparative analysis is performed for each section of the cycle revealing its individual transient characteristics.  相似文献   
506.
Dangerous marine stingers (jellyfish) are an emotive issue in tropical Australia, where they are widely regarded as the number one marine health threat. However, numerous severe and fatal stings have been reported throughout the tropical and temperate seas of the world, indicating that marine stingers are a global health problem. Further, life-threatening jellyfish stings are more frequently reported globally now compared to earlier decades, possibly as a result of improved recognition and reporting, or increased spatial and/or temporal distribution or densities. As stinging incidents may also have significant financial implications (lost tourism revenues and liability settlements), and the treatment of envenomed patients comes at high cost to the taxpayer, this issue is also a management challenge. This article outlines suggested approaches, based largely on Australian experience, for dealing with this under-recognized global coastal management issue.  相似文献   
507.
On the basis of annual expenditures by recreational participants and standard values of recreation days, as well as estimated sport and commercial harvests, the gross annual return from Michigan's 105,855 acres of coastal wetlands has been estimated. Analysis of fish, wildlife, and recreational values revealed that in 1977 these wetland areas generated an economic value of $489.69 per wetland acre, for a direct annual gross of $51.8 million. Specifically, these average return values per wetland acre/year, in descending order, are sport fishing ($286), nonconsumptive recreation ($138.24), waterfowl hunting ($31.23), trapping of furbearers ($30.44), and commercial fishing ($3.78). These gross annual return values were calculated in an effort to sensitize the general public to the diversity and possible magnitude of selected wetland functions.  相似文献   
508.
In this paper a proposal for a Competitive Rate of Return (CRR) based operating-subsidy system is made as an alternative to the existing US foreign-cost parity ODS system. Such an alternative, if adopted, could be successful in meaningfully relating US government maritime subsidy programmes to the legitimate financial needs of the industry. From the operator's viewpoint, the risk of drastic revenue fluctuations is removed, yet adequate opportunities are provided for firms with above average performance to be rewarded for their efficiency in higher than average profits. similarly, poorly run firms have an opportunity to lose money, in spite of government subsidies.

From the government's viewpoint, the CRR programme guarantees the provision of essential shipping services at the lowest possible cost. Because of substantial incentives to the operator on both the revenue and cost side of his profit equation, it is more likely that long-run government operating subsidies can be reduced under CRR than under the present system.

Although the CRR system has been described for use in determining subsidies for both bulk and general cargo carriers, it has been recommended that this system be considered first for implementation in the case of bulk vessels, because of the newness of the bulk subsidy programme. In addition, the 1970 Act gives MarAd the flexibility to initiate such a programme for bulk vessels without the necessity of new legislation.  相似文献   
509.
Book reviews     
THE SEVENTH AUSTRALIAN TRANSPORT RESEARCH FORUM, by K. W. Ogden.

AIRLINE PLANNING: CORPORATE, FINANCIAL AND MARKETING by Nawal K. Taneja. Lexington, Mass., Lexington Books, 1982. 207 pp. (£19.50)

SOLVING LOCAL GOVERNMENT PROBLEMS: PRACTICAL APPLICATIONS OF OPERATIONS RESEARCH IN CITIES AND REGIONS, by Charles E. Pinkus and Anne Dixson. George Allen and Unwin, London, 1981. (Hardback £20.00; paperback £8.95)

SCIENTIFIC MANAGEMENT OF TRANSPORT SYSTEMS, edited by N. K. Jaismal. Published by North‐Holland Publishing Company (U.S. $58.50)

TRANSPORTATION AND TRAFFIC ENGINEERING HANDBOOK (Second Edition), edited by W. S. Homburger, Englewood Cliffs, N.J., 1982. Prentice Hall, pp. 883.

ECONOMICS OF PUBLIC TRANSPORT, by C. A. Nash. Longman, London, pp. 194. (£6.95).  相似文献   
510.
Currently, the Hong Kong government imposes fare control on buses and taxi while the rail services are immune to such a control. This study examined four scenarios of fare deregulation on transit services by considering three related parties of a transit system – service providers, travelers, and society in general, with their respective objectives represented as – revenue, travel utility, and congestion. Analyzing the resultant impacts on these three parties, we found that a different regulatory environment would favor or hurt a different set of parties. There is no clear win‐win situation for all parties. Deciding a socially acceptable regulatory environment is likely to involve difficult tradeoffs among these parties.  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