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   279篇
  免费   1篇
公路运输   39篇
综合类   8篇
水路运输   98篇
铁路运输   4篇
综合运输   131篇
  2021年   2篇
  2020年   3篇
  2019年   5篇
  2018年   4篇
  2017年   12篇
  2016年   10篇
  2015年   5篇
  2014年   7篇
  2013年   49篇
  2012年   14篇
  2011年   15篇
  2010年   13篇
  2009年   9篇
  2008年   15篇
  2007年   6篇
  2006年   9篇
  2005年   4篇
  2004年   6篇
  2003年   10篇
  2002年   8篇
  2001年   4篇
  2000年   7篇
  1999年   5篇
  1998年   3篇
  1997年   7篇
  1996年   5篇
  1995年   4篇
  1994年   1篇
  1993年   4篇
  1992年   1篇
  1991年   2篇
  1989年   4篇
  1988年   1篇
  1986年   2篇
  1985年   2篇
  1983年   5篇
  1982年   4篇
  1981年   1篇
  1979年   3篇
  1977年   1篇
  1976年   1篇
  1975年   4篇
  1973年   2篇
  1972年   1篇
排序方式: 共有280条查询结果,搜索用时 0 毫秒
101.
This paper addresses the relationship between land use, destination selection, and travel mode choice. Specifically, it focuses on intrazonal trips, a sub-category of trip making where both trip origin and trip destination are contained in the same geographic unit of analysis, using data from the 1994 Household Activity and Travel Diary Survey conducted by Portland Metro. Using multinomial logit and binary logistic models to measure travel mode choice and decision to internalize trips, the evidence supports the conclusions that (1) intrazonal trips characteristics suggest mode choice for these trips might be influenced by urban form, which in turn affects regional trip distribution; (2) there is a threshold effect in the ability of economic diversity/mixed use to alter travel behavior; and (3) greater emphasis to destinations within the area where an individual’s home is located needs to be given in trip distribution models.  相似文献   
102.
Three-piece trucks have some drawbacks, particularly unstable operation of the friction wedge damping system. One of the principal features of systems of this kind is the possibility of jamming and wedging. This work is devoted to mathematical and numerical modeling of the plane motion of a freight car with allowance for the mobility of the wedges and then for the compliance of the contacting bodies and to the study of the conditions for the onset of jamming and wedging when the car is in motion.  相似文献   
103.
Siebert  Michael  Ellenberger  David 《Transportation》2020,47(6):3031-3045
Transportation - Automatic passenger counting (APC) in public transport has been introduced in the 1970s and has been rapidly emerging in recent years. Still, real-world applications continue to...  相似文献   
104.
105.
The most economical means of transporting crude oil over long distances is through the use of very large and ultra large crude containers (VLCCs and ULCCs respectively). These ships require sea lane depths of more than 55 feet to navigate. Since no major U.S. port is deeper than 45 feet, special offloading procedures must be employed. One such procedure is lightering, the process of offloading crude oil from VLCCs to smaller vessels for final delivery to the port.A linked set of queuing models is developed in an effort to understand lightering operations better and to enhance tradeoff analyses. The model assumes that port service times, lightering vessel loading times and VLCC interarrival times are exponentially distributed, allowing us to model lightering vessel operations using a cyclic queuing model. VLCC delays are modeled using an approximate M/Ek/S queue. The two models are linked through a VLCC service time model. The sensitivity of the model to changes in key inputs as well as the likely impacts of the model's assumptions and approximations are discussed. The paper concludes with recommendations for future studies.  相似文献   
106.
欧洲铁路宣布采用数字蜂窝式无线系统作为下一代欧洲铁路通信系统,此决定引起相当大的反响,一部分人认为应选择集群无线通信(TET-RA).  相似文献   
107.
The aim of this paper is to indicate some of the distinctive problems of executive leadership which surround the control of authority in merchant navy training schools in the United Satates, Great Britain, and Spain. On the basis of extensive field interviews with the staff and directors of two American, three British, and two Spanish, schools, our purpose is to suggest the conditions which give rise to the need for particular kinds of leadership styles, depending upon the manner by which nautical education is organized [1]. More specfi-cally, our thesis is that their organizationl chartering arrangements (defined as contractual and quasi-contractual linkages with variious third parties to nautical education) mandate specific kinds of internal structural patterns within nautical schools which, in turn, produce the need for different styles of executive leadership.  相似文献   
108.
This paper provides a commentary on the paper by Kiriazidis and Tzanidakis which examined a very significant area of policy relating to the European Union and the Maritime sector. Whilst providing a stimulus for discussion, their paper leaves out far more from the policy framework, than it includes and as such contributes little to the broader debate.  相似文献   
109.
This paper provides an analysis of the changes that have taken place in the Polish maritime sector between the demise of the Socialist state in 1989 and the current situation when the transformation process has had 10 years to develop. Examples are taken from the ports and shipping sectors and the conclusions provide an assessment of the structural implications of the transformation period for the overall maritime industry.  相似文献   
110.
Electronically controlled vehicle suspensions offer substantial improvements in performance over conventional, passive suspensions but with the price of power, complexity, and actuating bandwidth. Low-bandwidth, semi-active damping addresses the problems of power and bandwidth by using low power modulation of controllable dampers at the frequency of the isolated mass. Resistance controlled, semi-active damping is experimentally verified to better sprung mass isolation while reducing suspension stroke, something that a passive system cannot do. It is also shown to compare reasonably well with computer simulation results. The experimental implementation is a 1/30 scale, two degree-of-freedom test bed that represents the standard quarter vehicle model.  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