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   6336篇
  免费   308篇
公路运输   1291篇
综合类   2362篇
水路运输   1318篇
铁路运输   1290篇
综合运输   383篇
  2024年   19篇
  2023年   40篇
  2022年   101篇
  2021年   199篇
  2020年   155篇
  2019年   101篇
  2018年   110篇
  2017年   117篇
  2016年   116篇
  2015年   150篇
  2014年   481篇
  2013年   556篇
  2012年   551篇
  2011年   538篇
  2010年   395篇
  2009年   433篇
  2008年   460篇
  2007年   604篇
  2006年   562篇
  2005年   314篇
  2004年   174篇
  2003年   128篇
  2002年   98篇
  2001年   101篇
  2000年   50篇
  1999年   23篇
  1998年   21篇
  1997年   9篇
  1996年   7篇
  1995年   3篇
  1994年   7篇
  1993年   5篇
  1992年   2篇
  1991年   5篇
  1990年   4篇
  1989年   3篇
  1988年   1篇
  1986年   1篇
排序方式: 共有6644条查询结果,搜索用时 0 毫秒
131.
Traffic management during an evacuation and the decision of where to locate the shelters are of critical importance to the performance of an evacuation plan. From the evacuation management authority’s point of view, the desirable goal is to minimize the total evacuation time by computing a system optimum (SO). However, evacuees may not be willing to take long routes enforced on them by a SO solution; but they may consent to taking routes with lengths not longer than the shortest path to the nearest shelter site by more than a tolerable factor. We develop a model that optimally locates shelters and assigns evacuees to the nearest shelter sites by assigning them to shortest paths, shortest and nearest with a given degree of tolerance, so that the total evacuation time is minimized. As the travel time on a road segment is often modeled as a nonlinear function of the flow on the segment, the resulting model is a nonlinear mixed integer programming model. We develop a solution method that can handle practical size problems using second order cone programming techniques. Using our model, we investigate the importance of the number and locations of shelter sites and the trade-off between efficiency and fairness.  相似文献   
132.
As urban areas face increasing demands for new transport infrastructure to promote a sustainable future with an increasing reality of constrained government budgets, the debate on whether we should focus on rail or bus-based investments continues unabated in many jurisdictions. Associated with the debate is an emotional (or ideological) bias by communities in favour of one mode, especially rail, which carries much sway at the political level as if there is no budget constraint. This paper presents a stated choice experiment to investigate this context as two unlabelled options described by 20 potential drivers of community preferences for improved public transport, where each choice scenario is conditioned on an estimated construction cost and a total annual transport infrastructure budget for the relevant geographical jurisdiction. This is followed by a labelling of each alternative to reveal whether the option is bus rapid transit (BRT) or light rail (LRT) and to establish whether this additional information influences preference revision. Data is collected in all eight capital cities of Australia in mid 2014. Mixed logit models with heteroscedastic conditioning in terms of the cost of the project infrastructure and whether the alternative is labelled BRT or LRT, provide new evidence on the nature and extent of community modal bias in a budget-constrained choice setting. The conclusions are twofold. On the one hand, if a fully compensatory choice rule is assumed (as is common in all previous modal comparison studies), LRT is predominantly preferred over BRT despite budgetary constraints, similarities in quality of service attributes and the opportunity to choose a greater network coverage for a given construction cost. However, when we allow for attribute non-attendance (a semi-compensatory choice rule), the modal bias is no longer a significant driver of preferences.  相似文献   
133.
Transportation is a major cause for environmental degradation via exhaust emissions. For many transit-oriented metropolitan areas, bus trips often constitute a sizeable mode share. Managing the bus fleet, in particular updating buses to comply with the newer emissions standards, therefore, can have a substantial impact on transportation-induced air quality. This paper presents the approach of remaining life additional benefit–cost (RLABC) analysis for maximising the total net benefit by either early-retiring or retrofitting the current bus fleet within their lifespans. By referring to the net benefits for different bus types estimated by RLABC analysis, the most beneficial management scheme for the current bus fleet can be identified. Optimal bus fleet management (BFM) models based on the RLABC analysis for the operator and the government are developed. Then a government subsidy plan is produced to achieve win–win solutions, which will offer efficient and flexible management schemes. To illustrate the approach, the largest bus company in Hong Kong, which carries more than 23% of the total trips in Hong Kong, is taken as a case study example. Instead of adopting a fixed retirement plan, such as replacing buses at the age of 17 as is currently practised, the proposed method develops an optimal BFM scheme that progressively phases out buses or retrofits them. This study produces promising results to demonstrate the large benefit of this approach for optimal bus fleet management.  相似文献   
134.
文章结合相关理论和工程实践,总结分析了高寒路域边坡植被养护管理的现状,提出了高寒区植被养护的有效措施,为我国高寒区生态理论研究提供了实践依据。  相似文献   
135.
This paper examines some key aspects of a charging system for promoting railway transport, including charges reflecting a clear relationship with costs (transparency) and charges reflecting the quality of the infrastructure manager's service. Train running charges recover track-related costs and can help to develop a charging system that meets these requirements. To orient train running charges to the market, a method for processing track maintenance and renewal costs is proposed whereby the quality of the service provided by an infrastructure is measured according to its utility to the railway undertaking. To achieve transparency, a single indicator is used for cost planning and the subsequent levying of costs on railway undertakings. The paper includes an example of how proposed train running charges would be calculated according to data from 14 European countries. The example shows that short-distance trains generate the lowest maintenance and renewal costs, followed by long-distance trains and freight trains.  相似文献   
136.
文章介绍了当前广西道路货物运输行业的基本情况,阐述了广西道路货物运输安全生产存在的主要问题,并从行政管理和企业管理的角度,提出了切合广西道路货物运输行业实际的安全管理措施。  相似文献   
137.
A perspective view of of Japanese R&D activities of Driver Information Systems is given from the standpoint of developing joint projects by public and private sectors. First, a brief history of the R&D activities is illustrated from above mentioned standpoint. Then, two major projects, AMTICS and RACS, and the social backgrounds of these projects are explained. In order to give a clear idea of both projects some technical details are treated.Based on the history and the present status of the developments, the basic design conceptions of Japanese Driver Information Systems are explained and several factors or reasons which have influenced to the design conception are discussed. Then, the promoting systems of the R&D activities are generally explained and present status of the projects and future problems in developing more advanced systems are also handled. A brief discussion on the establishment of international standard is also mentioned as a final comment.  相似文献   
138.
Meligrana  John F. 《Transportation》1999,26(4):359-398
This paper discusses the evolving institutional structure and governance of transportation planning, policy development and transit delivery within one major North American city-region, the Greater Vancouver area. Various methods of transportation governance are explored from complete independence to full regional integration. The move away from a direct provincial role in transportation management to a greater regional transit authority is discussed and critiqued. This revised version was published online in June 2006 with corrections to the Cover Date.  相似文献   
139.
邵婷  陈忱 《时代汽车》2021,(7):49-50
伴随着时代的发展与信息技术的不断进步,人们的日常生活中发现了天翻地覆的变化,教师的教学工作也有了更多的便利条件,在对高职学生进行管理的过程中,有效的借助信息技术与自媒体环境能够更好的开展管理,同时也能够让管理工作变得更加高效.互联网的不断发展与普及,自媒体变成了传递信息的重要途径,这位高职学生管理工作提供了更多的里斯路...  相似文献   
140.
彭维 《时代汽车》2021,(7):174-176
客户是企业生存之本,客户需求的满足是企业各业务链条尤其是营销板块工作开展的核心触点。如何通过客户关系管理,并联营销业务各版块价值体现,最终实现客户满意,促进新客户转化和老客户再购,实现客户和企业双赢。本文结合商用车行业现状,提出了商用车大客户关系管理及营销业务并联的相关解决方案。  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