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   998篇
  免费   6篇
公路运输   248篇
综合类   39篇
水路运输   355篇
铁路运输   33篇
综合运输   329篇
  2022年   8篇
  2021年   7篇
  2020年   9篇
  2019年   15篇
  2018年   15篇
  2017年   25篇
  2016年   27篇
  2015年   16篇
  2014年   18篇
  2013年   151篇
  2012年   40篇
  2011年   48篇
  2010年   32篇
  2009年   45篇
  2008年   46篇
  2007年   35篇
  2006年   21篇
  2005年   21篇
  2004年   19篇
  2003年   27篇
  2002年   13篇
  2001年   14篇
  2000年   22篇
  1999年   9篇
  1998年   14篇
  1997年   18篇
  1996年   22篇
  1995年   26篇
  1994年   6篇
  1993年   13篇
  1992年   17篇
  1991年   9篇
  1990年   13篇
  1989年   6篇
  1988年   14篇
  1987年   12篇
  1986年   13篇
  1985年   13篇
  1984年   6篇
  1983年   17篇
  1982年   13篇
  1981年   19篇
  1980年   9篇
  1979年   9篇
  1978年   9篇
  1977年   6篇
  1976年   6篇
  1975年   13篇
  1974年   6篇
  1973年   7篇
排序方式: 共有1004条查询结果,搜索用时 15 毫秒
991.
A major research study funded by the UK Overseas Development Administration (ODA) and designed to establish the necessary considerations for viability of mass rapid transit railways in developing cities was recently completed. The analytical core of the study was a pre-appraisal model, which combines an innovative strategic land use/transport model utilizing relationships from developing cities and an economic evaluation model. This model — MRTAP — has now been developed into a user-friendly package which the ODA intend should be made widely available in the developing world. The paper describes the basis of this model.  相似文献   
992.
The purpose of this study is to examine the spatial and temporal characteristics of weekend work episodes. Specifically, we examine whether individuals work over the weekend and, if they work, whether they work at home or outside the home. We also model the time of day of weekend work. The empirical analysis in the paper is based on the 2000 San Francisco Bay Area Travel Survey. The results indicate the important effects of day of week/seasonal effects, individual demographics, work-related variables, household characteristics, and location variables on weekend work participation characteristics. The models estimated in the paper may be embedded within a larger weekend activity-travel pattern forecasting model system.  相似文献   
993.
This Note describes an investigation of spatial variations in the ambient concentrations of hydrocarbons in the vicinity of a suburban motorway during five consecutive weekday morning peak periods of unusually warm and calm conditions. Background-corrected downwind concentrations representing the influence of the motorway source were found to be strongly dependant on wind speed and direction. The ambient ethene-to-acetylene concentration ratio was greatest close to the roadside and the effect of wind speed on the ratio had different average profiles for main wind directions due to different rates of dispersal. Higher values were obtained using background-corrected concentrations.  相似文献   
994.
The present work poses a method for the measurement of geometric parameters of rail wheels in a dynamic condition, by reconstructing the profilogram from a portion of the wheel surface wear with artificial vision. The suggested procedure can work with a two-dimensional laser displacement transducer or by processing a sole image from a single camera with a structured light source. These two procedures require fewer devices and simpler implementation processes and allow the use of mathematical algorithms that demand less information processing, thus generating more accurate results. Railway operators may implement this method to perform predictive maintenance to their rolling stock at a fraction of the regular cost; thus achieving better precision, availability, maintenance performance and improving safety. Results were compared to those given by commercial equipment, showing similar precision but a better cost–benefit relation.  相似文献   
995.
996.
997.
Three of the most highly regarded disaggregate mode split models incorporate very different estimates of the responsiveness, or elasticity, of mode choice to changes in auto travel times and costs. These differences appear to be due in part to the varying specifications used by the model, and particularly whether certain variables (such as a dummy variable for CBD destinations or automobile ownership) are included in addition to the more traditional variables (such as travel time, cost, and household income). More research is needed on the implications of the theory of traveler choices for model specification and the effect of alternative, but theoretically justifiable, specifications on elasticity estimates. Until this research reduces our uncertainty about the elasticity of demand, analysts evaluating transportation policies should assess the sensitivity of their results to the range of plausible elasticities or models.  相似文献   
998.
Transportation - This paper provides an overview of the study ‘Provision of market research for value of time savings and reliability’ undertaken by the Arup/ITS Leeds/Accent consortium...  相似文献   
999.
A model is presented that relates the proportion of bicycle journeys to work for English and Welsh electoral wards to relevant socio-economic, transport and physical variables. A number of previous studies have exploited existing disaggregate data sets. This study uses UK 2001 census data, is based on a logistic regression model and provides complementary evidence based on aggregate data for the determinants of cycle choice. It suggests a saturation level for bicycle use of 43%. Smaller proportions cycle in wards with more females and higher car ownership. The physical condition of the highway, rainfall and temperature each have an effect on the proportion that cycles to work, but the most significant physical variable is hilliness. The proportion of bicycle route that is off-road is shown to be significant, although it displays a low elasticity (+0.049) and this contrasts with more significant changes usually forecast by models constructed from stated preference based data. Forecasting shows the trend in car ownership has a significant effect on cycle use and offsets the positive effect of the provision of off-road routes for cycle traffic but only in districts that are moderately hilly or hilly. The provision of infrastructure alone appears insufficient to engender higher levels of cycling.
Matthew PageEmail:

John Parkin   joined academia after a career in consultancy. He has experience of all stages of the promotion of transport infrastructure, from planning and modelling to design and implementation. His specialises in transport engineering with an emphasis on design innovation, sustainability principles and community benefit. Mark Wardman   has been involved in transport research for over 20 years. His main research interests are in behavioural response models in general and stated preference in particular. Areas of application have included public transport, notably rail, with several novel applications to cycling and environmental issues. Matthew Page   research interests include transport policy and how it has developed, the environmental impacts of transport, the impacts of transport on climate change, and walking and cycling.  相似文献   
1000.
Fishing is one of the most dangerous occupations in the world. Numerous research studies have been carried out to improve fishing safety from many different perspectives. Several of these studies focused on the relationship between environmental factors, climate change effects, and fishing safety. This paper aims to suggest a knowledge mobilization structure that translates findings of this type of research into input of evidence-based decision making and consequently improve and update fishing policies with respect to fishing safety and environmental conditions. Significant safety factors extracted from related literature are stability of vessels, fisheries management, safety equipment, communication, insurance, training, safety information and culture, weather forecasts, fatigue, and search and rescue planning. The paper then reviews policies related to these factors to examine if they address extreme environmental conditions and climate change effects. The paper presents recommendations to improve general fishing safety with respect to short- and long-term environmental considerations.  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