全文获取类型
收费全文 | 2241篇 |
免费 | 50篇 |
专业分类
公路运输 | 299篇 |
综合类 | 325篇 |
水路运输 | 321篇 |
铁路运输 | 1198篇 |
综合运输 | 148篇 |
出版年
2024年 | 3篇 |
2023年 | 3篇 |
2022年 | 20篇 |
2021年 | 41篇 |
2020年 | 48篇 |
2019年 | 21篇 |
2018年 | 21篇 |
2017年 | 32篇 |
2016年 | 34篇 |
2015年 | 47篇 |
2014年 | 174篇 |
2013年 | 113篇 |
2012年 | 178篇 |
2011年 | 162篇 |
2010年 | 153篇 |
2009年 | 147篇 |
2008年 | 159篇 |
2007年 | 199篇 |
2006年 | 175篇 |
2005年 | 160篇 |
2004年 | 131篇 |
2003年 | 61篇 |
2002年 | 42篇 |
2001年 | 44篇 |
2000年 | 19篇 |
1999年 | 23篇 |
1998年 | 14篇 |
1997年 | 19篇 |
1996年 | 12篇 |
1995年 | 11篇 |
1994年 | 12篇 |
1993年 | 3篇 |
1992年 | 8篇 |
1991年 | 2篇 |
排序方式: 共有2291条查询结果,搜索用时 15 毫秒
171.
172.
173.
桥梁施工监控在桥梁建设及加固改造工程中是必不可少的一部分,监控可以对桥梁线形及内力、挠度情况进行实时反馈,严格把关,保证与设计一致。文章以九曲河大桥加固工程为背景,结合加固改造设计方案,从线形控制、变形监测与应力监测等方面阐述了施工监控技术及效果。 相似文献
174.
Athanasios Matzoros 《运输规划与技术》2013,36(3):215-237
This article reports on an implementation study of a computerised decision support system for public transport management for the Athens Public Transport Authority (APTA). The study analysed the current situation, specified user requirements, determined system functionality, designed the system architecture, organised the project and, finally, planned dissemination activities. The decision support system covers the main public transport management activities of APTA - transport service provision, economic and financial planning, passenger complaints and suggestions, and personnel management - offering its users the possibility to study the potential effects of their decisions before implementation. To achieve this, the system will consist of a data warehousing system, for the integrated management of a wide variety of data sources, and of online analytical processing tools, for information analysis and scenario testing. The system architecture has been designed to offer robustness, flexibility, rich functionality and open connectivity. The system aims to help APTA reduce operational costs and provide a better transport service, attracting more passengers to public transport and reducing, in the process, congestion and pollution. 相似文献
175.
In urban areas where transit demand is widely spread, passengers may be served by an intermodal transit system, consisting of a rail transit line (or a bus rapid transit route) and a number of feeder routes connecting at different transfer stations. In such a system, passengers may need one or more transfers to complete their journey. Therefore, scheduling vehicles operating in the system with special attention to reduce transfer time can contribute significantly to service quality improvements. Schedule synchronization may significantly reduce transfer delays at transfer stations where various routes interconnect. Since vehicle arrivals are stochastic, slack time allowances in vehicle schedules may be desirable to reduce the probability of missed connections. An objective total cost function, including supplier and user costs, is formulated for optimizing the coordination of a general intermodal transit network. A four-stage procedure is developed for determining the optimal coordination status among routes at every transfer station. Considering stochastic feeder vehicle arrivals at transfer stations, the slack times of coordinated routes are optimized, by balancing the savings from transfer delays and additional cost from slack delays and operating costs. The model thus developed is used to optimize the coordination of an intermodal transit network, while the impact of a range of factors on coordination (e.g., demand, standard deviation of vehicle arrival times, etc) is examined. 相似文献
176.
铁路CTC网络均采用了带访问控制功能的路由器,正确地设置ACL(访问控制列表),将起到防火墙的作用,降低网络安全风险。在CTC网络路由器上进行规则设定,可阻挡不匹配安全规则的数据包,确保CTC网络安全。 相似文献
177.
Abstract This article documents the authors' experience with the modeling, simulation, and analysis of a university transportation system, using the TRansportation ANalysis and SIMulation System (TRANSIMS). The processes of data preparation and network coding are described, followed by the algorithm developed to estimate the dynamic 24-hour demand, which includes a procedure for estimating the ‘desirability’ of the different parking lots from readily available data. The dynamic demand estimation algorithm is validated by comparing estimated and observed parking lot occupancies, where it is shown that the algorithm is capable of replicating observed results. Finally, an example is included to demonstrate how the developed model can be used in campus transportation planning. Besides serving as a first case study for using TRANSIMS to model a university campus, the study's contributions include the development of a procedure for parking lot desirability ranking and a practical procedure for estimating dynamic demand on university campuses. 相似文献
178.
客运专线铁路隧道高陡坡洞口开裂整治技术研究 总被引:1,自引:1,他引:0
《铁道标准设计通讯》2016,(3):112-116
以宝兰客运专线塔稍村隧道为依托,分析隧道进口边坡及洞内裂缝的成因,评价边坡的稳定性,并提出具体的处理措施。对该隧道地层岩性、构造属性、围岩等级等进行阐述,针对该边坡建立系统的地表及洞内变形监测网并进行钻孔内位移测量工作,结合详细的地质调查,查明隧道进口处边坡、洞口挡墙、隧道内二衬裂缝的成因和基本特征,结合区段的工程地质特征,提出合理的工程处理措施,为类似工程的调查与处理提供参考。 相似文献
179.
Real time monitoring of driver attention by computer vision techniques is a key issue in the development of advanced driver assistance systems. While past work mostly focused on structured feature-based approaches, characterized by high computational requirements, emerging technologies based on iconic classifiers recently proved to be good candidates for the implementation of accurate and real-time solutions, characterized by simplicity and automatic fast training stages.In this work the combined use of binary classifiers and iconic data reduction, based on Sanger neural networks, is proposed, detailing critical aspects related to the application of this approach to the specific problem of driving assistance. In particular it is investigated the possibility of a simplified learning stage, based on a small dictionary of poses, that makes the system almost independent from the actual user.On-board experiments demonstrate the effectiveness of the approach, even in case of noise and adverse light conditions. Moreover the system proved unexpected robustness to various categories of users, including people with beard and eyeglasses. Temporal integration of classification results, together with a partial distinction among visual distraction and fatigue effects, make the proposed technology an excellent candidate for the exploration of adaptive and user-centered applications in the automotive field. 相似文献
180.