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   3356篇
  免费   276篇
公路运输   942篇
综合类   1163篇
水路运输   880篇
铁路运输   550篇
综合运输   97篇
  2024年   20篇
  2023年   33篇
  2022年   125篇
  2021年   188篇
  2020年   127篇
  2019年   78篇
  2018年   73篇
  2017年   91篇
  2016年   69篇
  2015年   116篇
  2014年   160篇
  2013年   220篇
  2012年   258篇
  2011年   295篇
  2010年   306篇
  2009年   256篇
  2008年   212篇
  2007年   266篇
  2006年   260篇
  2005年   202篇
  2004年   80篇
  2003年   46篇
  2002年   40篇
  2001年   57篇
  2000年   41篇
  1999年   10篇
  1997年   2篇
  1994年   1篇
排序方式: 共有3632条查询结果,搜索用时 8 毫秒
801.
黄小林 《湖南交通科技》2007,33(1):116-118,149
介绍了长沙市三汊矶大桥西岸65 m跨箱梁顶推施工工艺、施工技术和施工控制,对顶推预制场的优化设计、导梁的合理配置、临时墩设计施工、墩顶水平偏位的控制及箱梁的导向与纠偏等关键施工技术进行了探讨。  相似文献   
802.
为提高轨道交通与其他交通的换乘效率,本文考虑轨道交通出行者的个人属性、家庭社会经济因素、出行属性等建立基于Logit模型的城市轨道交通接驳选择预测模型。借助spss软件对模型参数进行拟合和检验,研究结果表明出行者的家庭收入、接驳距离、接驳费用等因素对接驳轨道交通均有影响。模型的精度高达81%,接驳选择预测模型能够很好地应用于对轨道交通接驳方式的预测。  相似文献   
803.
Camera calibration is the key technique in a C-arm based orthopaedic surgical navigation system. The extraction of marker location information is a necessary step in the calibration process. Ideal marker images should possess uniform background and contain marker shadow only, but in fact marker images always possess nonuniform background and are contaminated by noise and unwanted anatomic information, making the extraction very difficult. A target-orientated marker shadow extraction method was proposed. With this method a proper threshold for marker image binarization can be determined.  相似文献   
804.
A new approach to maintenance scheduling of generating units(MSU)in competitive electricity markets was presented,which was formulated as a noncooperative game with complete information.The payoff of each generating company(Genco)was defined as the profit from the energy auction market minus maintenance cost and risk loss.The compensation fee of interruptible load was a part of the maintenance cost when the permitted maintenance capacity in the system was insufficient.Hourly energy auction was incorporated in the computation of both revenues from energy market and risk loss of maintenance strategy as a nested game.A new heuristic search algorithm for the calculation of the game equilibrium of MSU was presented,which coordinates the solutions of non-equilibrium,unique equilibrium and multiple equilibria.Numerical results for a two-Genco system and a realistic system were used to demonstrate the basic ideas and the applicability of the proposed method,as well as its computational efficiency.  相似文献   
805.
A novel nonlinear combination process monitoring method was proposed based on techniques with memory effect (multivariate exponentially weighted moving average (MEWMA)) and kernel independent component analysis (KICA). The method was developed for dealing with nonlinear issues and detecting small or moderate drifts in one or more process variables with autocorrelation. MEWMA charts use additional information from the past history of the process for keeping the memory effect of the process behavior trend. KICA is a recently developed statistical technique for revealing hidden, nonlinear statistically independent factors that underlie sets of measurements and it is a two-phase algorithm: whitened kernel principal component analysis (KPCA) plus independent component analysis (ICA). The application to the fluid catalytic cracking unit (FCCU) simulated process indicates that the proposed combined method based on MEWMA and KICA can effectively capture the nonlinear relationship and detect small drifts in process variables. Its performance significantly outperforms monitoring method based on ICA, MEWMA-ICA and KICA, especially for long-term performance deterioration.  相似文献   
806.
虹桥综合客运枢纽车道边规模论证与仿真评价   总被引:1,自引:0,他引:1  
采用理论计算与软件仿真相结合的方式.依托对现有虹桥机场与浦东机场车道边上落客特征调查数据分析.对规划中的虹桥枢纽车道边的适用规模进行建模论证.并通过仿真软件对不同车道边形式的集散效果进行评价,可为虹桥综合客运枢纽的规划设计提供理论和技术支撑。  相似文献   
807.
基于GIS的道路交通信息系统研究   总被引:1,自引:1,他引:1  
交通系统中,信息手段的有效运用能起到运输系统能量倍增器的作用。随着智能交通的发展,运用GIS技术,通过配置数据网络布局、建立道路网GIS空间数据库和地图要素属性数据库构建的道路交通信息系统,实现了交通信息的实时输入与输出及电子政务、安全监控等的应用。  相似文献   
808.
The degraded parameters recognition is very important for the restoration of blurred images. There are two common types of blurs for most camera systems. One is the defocus blur due to the optical system's defocus phenomenon and the other is the motion blur due to the relative movement between the objectives and the camera. Compared with the recognition for the blurred image with only one blur model, the parameter estimation for the picture combining defocus and motion blur models is a more complicated mission. A method was proposed for computer to estimate the parameters of defocus blur and motion blur in cepstrum area simultaneously. According to characters of both blur models in the frequency domain, an adjustment approach was suggested in the frequency area and then convert to the cepstrum field to increase the accuracy of measurement.  相似文献   
809.
从城市生态角度探讨了交通对城市生态的负面影响及其主要对策.主要例举了不良城市交通对城市自然生态系统构成的八大影响,和针对这八大影响可以采取的主要对策,包括宏观方面的对策和微观方面的对策.最后,就宏观对策和微观对策中存在的主要问题,以及对"先污染,再治理"的发展道路对现代城市病的影响,进一步的作出一些探讨和思考.  相似文献   
810.
深圳市汽车拥有量与机动化出行需求迅猛增长,迫切要求大力发展公共交通.规划在市区北部建设BRT1号线。论文阐明了深圳BRT1号线建设必要性,提出了线路方案、场站布局方案与运营线路组织方案。  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