全文获取类型
收费全文 | 884篇 |
免费 | 8篇 |
专业分类
公路运输 | 308篇 |
综合类 | 36篇 |
水路运输 | 289篇 |
铁路运输 | 33篇 |
综合运输 | 226篇 |
出版年
2023年 | 10篇 |
2022年 | 20篇 |
2021年 | 9篇 |
2020年 | 8篇 |
2019年 | 7篇 |
2018年 | 34篇 |
2017年 | 14篇 |
2016年 | 30篇 |
2015年 | 7篇 |
2014年 | 31篇 |
2013年 | 131篇 |
2012年 | 33篇 |
2011年 | 47篇 |
2010年 | 35篇 |
2009年 | 46篇 |
2008年 | 47篇 |
2007年 | 21篇 |
2006年 | 10篇 |
2005年 | 17篇 |
2004年 | 18篇 |
2003年 | 5篇 |
2002年 | 13篇 |
2001年 | 8篇 |
2000年 | 14篇 |
1999年 | 10篇 |
1998年 | 23篇 |
1997年 | 14篇 |
1996年 | 19篇 |
1995年 | 16篇 |
1994年 | 5篇 |
1993年 | 7篇 |
1992年 | 12篇 |
1991年 | 8篇 |
1990年 | 11篇 |
1989年 | 8篇 |
1988年 | 5篇 |
1987年 | 9篇 |
1986年 | 8篇 |
1985年 | 8篇 |
1984年 | 9篇 |
1983年 | 12篇 |
1982年 | 7篇 |
1981年 | 12篇 |
1980年 | 8篇 |
1979年 | 15篇 |
1977年 | 15篇 |
1976年 | 11篇 |
1975年 | 10篇 |
1974年 | 8篇 |
1973年 | 5篇 |
排序方式: 共有892条查询结果,搜索用时 0 毫秒
201.
The new Badaling tunnel is the longest tunnel on the under-construction Beijing-Zhangjiakou highspeedrailway, with the Badaling Great Wall station to be built in the tunnel. This station, which is under the Badaling Great Wall historic site, is the world’s largest underground high-speed railway station with the most complicated structure and the largest overburden and excavation area. It is therefore a representative project for China’s highspeed railway development strategy, supporting infrastructure facilities for the Beijing Horticultural Expo 2019 and the 2022 Winter Olympics in Beijing, and it is important that it be of high quality and completed safely. In the de-sign and construction of the station, the glyphs of the Chinese characters of "中",”国”,”人”and”品”are used, re-spectively, along the station route, in the rescue and evacuation mode, auxiliary adit and partial excavation, which is a way to successfully integrate the art of Chinese characters into tunnel engineering. © 2018, Editorial Office of "Modern Tunnelling Technology". All right reserved. 相似文献
202.
The aim of this work is the design of an algorithm for on-board determination of the actual capacity of a lithium iron phosphate (LFP) cathode-based lithium-ion battery for electric vehicle applications. The presented approach is based on the detection of the predominant aging mechanisms (in terms of loss of lithium and loss of active material in both electrodes) by determining the single electrode voltage curves. The information related to the characteristic length and position of the voltage plateaus, which can be gathered during battery operation, can be used to obtain the actual aging state of the cells. The length of the plateaus depends on the respective position that the voltage curves of the single electrodes have in relation to each other. Relating the change of the plateau characteristics to the possible aging mechanisms allows the determination of the actual battery aging state in terms of total cell capacity. The work presents a possible implementation of an algorithm for capacity determination based on the described methodology. The algorithm is validated with various differently aged LFP cells. Furthermore, the work discusses the ability of the method to detect the actual battery capacity if the characteristics of only part of the quasi-OCV (open circuit voltage) curve are detected. Achieved accuracy and existing limitations are described and discussed in detail. 相似文献
203.
Transportation - Recent studies have analyzed travel behavior over the life course through the lens of the mobility biography approach. Similarities in the effects of certain key events on travel... 相似文献
204.
205.
Theodore S. Glickman Hanif D. Sherali 《Transportation Research Part B: Methodological》1985,19(2):85-94
A set of models and procedures is described for finding the optimal distribution of empty freight cars owned by the railroads participating in a pooling agreement. A distinction is drawn between a system focus, in which the emphasis is on minimizing total cost, and a company focus, in which the benefits of the agreement to the individual railroads are emphasized. Limited car substitution is accounted for by combining interchange costs with distribution costs, and incorporating interchange possibilities and prohibitions into the network structure. Temporal variations in car supply and demand levels are also taken into account. A large-scale network algorithm is used in conjunction with decomposition to obtain solutions which show for a given time horizon how much equity can be achieved in the balance of savings among the railroads involved and at what cost. Results using actual operating data are reported. 相似文献
206.
To be beneficial to management, productivity concepts must be translated into terms that are meaningful to managers at all levels of the organization. Productivity per se is not nearly as important to these people as service quality and financial performance, especially since measured productivity can improve while profits or service levels decline. Productivity must, therefore, be related to an integrated set of performance measures that reflect costs, revenues, trip times and reliability, equipment availability and other matters of continuing concern to transportation companies. Planning and control are critical components of any program to improve productivity. The techniques required to measure and understand productivity are precisely those used in planning and in developing control systems. Furthermore, productivity is conceptually very close to cost analysis, which is a major focus of planning and control. Any transportation company has access to the data needed to develop a vast array of performance measures, including many productivity measures. This paper will illustrate the way that railroads can integrate productivity concepts within more global performance measurement systems. Specific attention will be given to terminal control systems, costing systems for origin-to-destination movements and life-cycle costing techniques for track maintenance planning. 相似文献
207.
Vanessa J. Maxwell John Supan Lisa C. Schiavinato Stephanie Showalter Granvil D. Treece 《Coastal management》2013,41(3):241-253
The goal of this study is to apply industrial park concepts to the development of aquaculture parks in public waters. The objectives are to identify the permitting process, relevant agencies, and legislation needed to facilitate development. Gulf of Mexico states are surveyed: private parks exist in Florida, but no public parks have developed yet; plans for parks exist in Mississippi, but lack of funding prevents development; no regulations prohibit parks in Alabama, although none currently exist; Texas regulations hinder development of parks; and an experimental park has been proposed in Louisiana, but regulatory gaps have delayed permit issuance. 相似文献
208.
209.
E. D. Brown 《Maritime Policy and Management》2013,40(6):325-350
It is highly probable that one of the results of the Third United Nations Conference on the Law of the Sea will be the recognition of a new jurisdictional zone—the exclusive economic zone (EEZ). This 200-mile zone will be used for a variety of potentially conflicting purposes by both the coastal state and non-coastal states and it is therefore important to ensure that the new convention emerging from the conference should establish criteria and make provision for machinery for the resolution of the international conflicts between different users which will undoubtedly arise. This paper contains a critical analysis of the latest draft articles under consideration at the Conference and considers the criteria by reference to which disputes might be resolved. 相似文献
210.