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   838篇
  免费   48篇
公路运输   205篇
综合类   374篇
水路运输   129篇
铁路运输   104篇
综合运输   74篇
  2024年   1篇
  2023年   3篇
  2022年   15篇
  2021年   39篇
  2020年   22篇
  2019年   22篇
  2018年   22篇
  2017年   23篇
  2016年   21篇
  2015年   29篇
  2014年   69篇
  2013年   47篇
  2012年   78篇
  2011年   77篇
  2010年   67篇
  2009年   56篇
  2008年   52篇
  2007年   84篇
  2006年   56篇
  2005年   27篇
  2004年   12篇
  2003年   7篇
  2002年   13篇
  2001年   14篇
  2000年   2篇
  1999年   6篇
  1998年   4篇
  1997年   1篇
  1996年   4篇
  1995年   4篇
  1994年   3篇
  1992年   2篇
  1990年   1篇
  1987年   2篇
  1984年   1篇
排序方式: 共有886条查询结果,搜索用时 890 毫秒
731.
海军装备领域人因工程研究现状及发展   总被引:1,自引:0,他引:1  
从军事装备领域人因工程的概念和意义、人因工程在我国及美国的相关发展情况出发,针对我国海军装备领域的人因工程,系统梳理海军装备人因工程研究范畴及相关技术手段,提出海军装备人因工程工作实施建议,展望未来海军装备领域新交互技术发展的特点,为我国海军装备领域人因工程研究工作及后续发展思路提供一定的参考.  相似文献   
732.
Although cluster analysis is recommended by the US Traffic Monitoring Guide (TMG) to supplement the development of seasonal adjustment factor groupings (SAFGs), the relationships among SAFGs' characteristics remain undiscovered, while the determination of the optimal number of clusters is an ambiguous task exposed to great subjectivity. Statistical indicators provide a mathematical solution by removing engineering judgment without taking into consideration any guidelines or other criteria, necessary for transportation planners to generate ‘practical and sensible’ groupings. The method examined in this study aims to overcome the above weaknesses incorporating into the methodology a series of statistics, recommendations, and previous research findings. The investigation of the relationships among (1) the within-group variation, (2) the total number of sites, (3) the minimum number of stations within a cluster, (4) the optimal number of clusters, and (5) the geographical size of the groups constitutes the main objectives of this research. According to the results, the cluster variability declines as the available number of stations increases. When the minimum number of stations within a cluster increases, the weighted coefficient of variation inflates as well, with the rate of increase depending on sample size. The average number of automatic traffic recorders per cluster is analogous to the sample size, while the optimal number of clusters varies conversely with the minimum number of stations within a cluster. The application developed for the conduct of the analysis minimizes the computational time needed, while it can be easily implemented by engineers to automate the process recommended by the TMG, enhancing the current state of practice.  相似文献   
733.
地铁交通快捷特征的指标——发车间隔和旅行速度并未达到令人满意的程度,在地面交通快速化之后能否保持优势值得关注.它们受到信号闭塞关系的制约,还涉及车辆、线路、供电和运营等专业,影响各有不同.通过两项指标的计算数值,说明系统设计和运营操作中提升指标的落脚点.  相似文献   
734.
近年来,高速铁路在西北地区建设中遇到大量的盐渍土路基,而盐渍土路基很容易发生溶陷变形,这对高速铁路的平顺性有着极为不利的影响。结合兰新铁路第二双线的盐渍土溶陷病害实例,使用改进的普通固结仪开展单因素溶陷试验,以其试验结果为基础,通过正交设计方法开展多因素交互作用下的盐渍土溶陷试验;采用SPSS软件对试验结果开展逐步回归分析,并根据分析结果中方差大小,消除不显著因素,建立溶陷系数简化预测模型,并对所得预测模型进行验证,确定影响氯盐渍土溶陷预变形的因素敏感性。研究结果表明:影响盐渍土的溶陷系数的敏感性因素由高到低排序依次为压实度,轴向压力,含盐量以及轴向压力与压实度的相互作用,影响所占比例分别为0.463,0.172,0.140,0.092。  相似文献   
735.
如何保证沥青混凝土路面的平整度,提高路面工程的质量,是高等级公路建设中的难点、重点。分析影响路面平整度的因素,从基础处理、材料控制、施工工艺等方面提出改善路面平整度的措施。  相似文献   
736.
加入WTO对我国航运市场影响的研究   总被引:3,自引:0,他引:3  
在研究我国目前航运7市场现状的基础上,分析国际航运的可控制影响因素,提出加入WTO后将对我国航运市场产生的影响,并制定若干对策。  相似文献   
737.
隧道洞口交通安全影响因素分析与对策   总被引:7,自引:0,他引:7  
高速公路隧道洞口变通事故原因具有多样性、复杂性的特点。通过对高速公路上隧道洞口变通事故特征的调查.以人、车、路和周围环境体系分析隧道洞口交通安全的影响因素,有利于提出隧道洞口变通安全性的合理对策。  相似文献   
738.
TBM施工深埋隧洞围岩分类方法初探   总被引:1,自引:0,他引:1  
文章针对TBM施工隧洞的围岩分类问题,分析了西南某水电站深埋隧洞影响洞室稳定性的因素,以<水利水电工程地质勘察规范>中的围岩分类方法(HC分类)为基础,依据岩石单轴抗压强度、岩体的完整性系数、岩体结构为主要因素来探讨适合TBM施工深埋隧洞的围岩分类.  相似文献   
739.
Activity-travel behavior research has hitherto focused on the modeling and understanding of daily time use and activity patterns and resulting travel demand. In this particular paper, an analysis and modeling of weekly activity-travel behavior is presented using a unique multi-week activity-travel behavior data set collected in and around Zurich, Switzerland. The paper focuses on six categories of discretionary activity participation to understand the determinants of, and the inter-personal and intra-personal variability in, weekly activity engagement at a detailed level. A panel version of the Mixed Multiple Discrete Continuous Extreme Value model (MMDCEV) that explicitly accounts for the panel (or repeated-observations) nature of the multi-week activity-travel behavior data set is developed and estimated on the data set. The model also controls for individual-level unobserved factors that lead to correlations in activity engagement preferences across different activity types. To our knowledge, this is the first formulation and application of a panel MMDCEV structure in the econometric literature. The analysis suggests the high prevalence of intra-personal variability in discretionary activity engagement over a multi-week period along with inter-personal variability that is typically considered in activity-travel modeling. In addition, the panel MMDCEV model helped identify the observed socio-economic factors and unobserved individual specific factors that contribute to variability in multi-week discretionary activity participation.
Kay W. AxhausenEmail:

Erika Spissu   is currently a Research Fellow at the University of Cagliari (Italy). She received her Ph.D. from the University of Palermo and University of Cagliari (Italy) in Transport techniques and economics. She spent the past 2 years at the University of Texas at Austin as a Research Scholar focusing primarily in activity-based travel behavior modeling, time use analysis, and travel demand forecasting. Abdul Rawoof Pinjari   is an Assistant Professor in the Department of Civil and Environmental Engineering at the University of South Florida, Tampa. His research interests include time-use and travel-behavior analysis, and activity-based approaches to travel-demand forecasting. He has his Ph.D. from the University of Texas at Austin. Chandra R. Bhat   is a Professor in Transportation at The University of Texas at Austin. He has contributed toward the development of advanced econometric techniques for travel behavior analysis, in recognition of which he received the 2004 Walter L. Huber Award and the 2005 James Laurie Prize from the American Society of Civil Engineers (ASCE), and the 2008 Wilbur S. Smith Distinguished Transportation Educator Award from the Institute of Transportation Engineers (ITE). He is the immediate past chair of the Transportation Research Board Committee on Transportation Demand Forecasting and the International Association for Travel Behaviour Research. Ram M. Pendyala   is a Professor of Transportation Systems in the Department of Civil, Environmental, and Sustainable Engineering at Arizona State University. He teaches and conducts research in travel behavior analysis, travel demand modeling and forecasting, activity-based microsimulation approaches, and time use. He specializes in integrated land use—transport models, transport policy formulation, and public transit planning and design. He is currently the Vice-Chair of the International Association for Travel Behavior Research and is the immediate past chair of the Transportation Research Board Committee on Traveler Behavior and Values. He has his PhD from the University of California at Davis. Kay W. Axhausen   is a Professor of Transport Planning at the Swiss Federal Institute of Technology (ETH) Zurich. Prior to his appointment at ETH, he worked at the Leopold Franzens University of Innsbruck, Imperial College London and the University of Oxford. He has been involved in the measurement and modelling of travel behaviour for the last 25 years, contributing especially to the literature on stated preferences, microsimulation of travel behaviour, valuation of travel time and its components, parking behaviour, activity scheduling and travel diary data collection.  相似文献   
740.
论述了土基永久变形的发展机理及其危害性,并从内、外因两个方面分析了影响土基永久变形的重要因素,为利用室内重复荷载三轴试验研究路基土的永久变形特性提供了参考依据。  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