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   3254篇
  免费   116篇
公路运输   882篇
综合类   1451篇
水路运输   510篇
铁路运输   391篇
综合运输   136篇
  2024年   14篇
  2023年   12篇
  2022年   41篇
  2021年   75篇
  2020年   80篇
  2019年   31篇
  2018年   23篇
  2017年   38篇
  2016年   33篇
  2015年   76篇
  2014年   251篇
  2013年   236篇
  2012年   307篇
  2011年   281篇
  2010年   271篇
  2009年   212篇
  2008年   270篇
  2007年   319篇
  2006年   305篇
  2005年   155篇
  2004年   90篇
  2003年   72篇
  2002年   58篇
  2001年   50篇
  2000年   26篇
  1999年   14篇
  1998年   9篇
  1997年   4篇
  1996年   4篇
  1995年   2篇
  1994年   1篇
  1993年   3篇
  1992年   3篇
  1991年   2篇
  1990年   1篇
  1989年   1篇
排序方式: 共有3370条查询结果,搜索用时 125 毫秒
991.
Shiftan  Yoram  Suhrbier  John 《Transportation》2002,29(2):145-168
This paper demonstrates, tests and shows the value of activity-based travel demand models and household sample enumeration forecasting techniques in evaluating the transportation and air quality impacts of travel demand management strategies. Using data from the Portland, Oregon metropolitan area, three transportation policies were evaluated both individually and in combination: transit improvements, pricing, and telecommunications. The activity-based models used in this testing represents a significant improvement to today's "four-step" sequential model systems by providing a deeper insight into the individual decision making process in response to transportation policies. A wider range of impacts is predicted, and indirect effects as well as synergistic effects of such policies are taken into consideration. These models are capable of providing the information needed to improve the linkage of transportation models with emissions and air quality analysis methodologies by improving the prediction of variables that are important to accurately estimating emissions and air quality impacts of transportation actions.  相似文献   
992.
秦岭隧道排出水化学异常对地表水质影响评价   总被引:1,自引:0,他引:1  
为评价隧道施工和排出水对地表水体水质的影响,对两条河流的水质进行了监测。现以饮用水水质都分因子为标准,将地表水水质划分为3个级别,并采用模糊综合评判法和灰色模型法对3个监测断面的地表水水质进行了综合评价,结果表明,两条河流水质良好,基本未受隧道施工及排出水的影响。  相似文献   
993.
IntroductionDistributed multimedia systems integrate a va-riety of media,including time dependent media,such as audio and video,and time independent me-dia,such as text,graphics,and images.Multime-dia synchronization refers to the temporal composi-tion of the data streams. Strams can be composedof temporal series of information units called Logi-cal Data Units (LDU) (e.g.,a video stream is atemporal series of video frames) .Multimedia synchronization can be modeledaccording to different gra…  相似文献   
994.
就目前高等级公路建设中存在的问题 ,提出要从设计、招标、施工、监理四个环节上进行强化管理 ,提高人员素质 ,引入竞争机制 ,加强内容管理 ,确保工程质量。  相似文献   
995.
详细介绍了哈尔滨市道路桥梁工程处质量体系认证过程 ,特别强调了其中的人员培训教育工作和质量体系文件编制工作及内审工作的运作 ,为交通系统其它单位通过ISO90 0 0标准体系认证提供了一些可供借鉴的经验。  相似文献   
996.
在公路施工过程中受竞标和质量控制的要求 ,计量工作越来越显示出其重要的作用 ,要做好计量工作必须做到以下几点 :明确计量程序、明确计量依据、明确工程量清单中的各章的计量  相似文献   
997.
高校学报发表的文章科技含量高、学术性理论性强,因而对学报编辑人员的素质提出很高的要求.本文就知识经济和网络经济时代学报编辑人员应具备的素质作了较详细的论述.  相似文献   
998.
铁路确报是铁路运输生产的重要内容,是铁路TMIS中重要的信息之一,既有的确报格式存在一些弊端,更改确报格式已成为提高确报信息质量的必须工作.介绍新确报格式内容以及实现流程.  相似文献   
999.
1000.
The measurement of transit service quality is very important for guaranteeing a transport supply characterized by satisfactory service levels for the passengers. Even more important is the monitoring of the levels of service quality over time, which can be very useful to determine if the goals established by the transport planners are being met or exceeded. The status and evolution of transit service quality can be monitored through periodic and regular updating of the opinions expressed by the passengers about the service during the well-known Customer Satisfaction Surveys, allowing the effect of policies to be evaluated and specific interventions to be introduced. In this work, just the issue of monitoring service quality based on users’ opinions is approached, and the index numbers usually applied in the economic and industrial field are proposed for this purpose. Index numbers permit to study the fluctuations or variations of a variable or more variables over time, providing a powerful measurement for making comparisons and predictions of the analyzed concept. The index numbers were calculated on the basis of data collected from Customer Satisfaction Surveys addressed to the passengers of the metropolitan public service of Granada (Spain). The analyzed time period has been established from 2007 to 2013. Interesting results derive from the calculation of the index numbers. Since both perceptions and importance rates are considered in this methodology, the results can inform, not only on the satisfaction tendencies but also on the trend on customers’ priorities, which is actually the expected quality. Therefore, policies could more efficiently be designed to adjust the service to the users’ real needs.  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