全文获取类型
收费全文 | 165篇 |
免费 | 4篇 |
专业分类
公路运输 | 28篇 |
综合类 | 47篇 |
水路运输 | 26篇 |
铁路运输 | 39篇 |
综合运输 | 29篇 |
出版年
2022年 | 1篇 |
2021年 | 7篇 |
2020年 | 8篇 |
2019年 | 5篇 |
2018年 | 2篇 |
2017年 | 5篇 |
2016年 | 5篇 |
2015年 | 6篇 |
2014年 | 13篇 |
2013年 | 16篇 |
2012年 | 11篇 |
2011年 | 19篇 |
2010年 | 10篇 |
2009年 | 6篇 |
2008年 | 7篇 |
2007年 | 13篇 |
2006年 | 10篇 |
2005年 | 8篇 |
2004年 | 4篇 |
2003年 | 5篇 |
2001年 | 1篇 |
2000年 | 2篇 |
1999年 | 1篇 |
1997年 | 1篇 |
1994年 | 2篇 |
1993年 | 1篇 |
排序方式: 共有169条查询结果,搜索用时 0 毫秒
31.
32.
鉴于公路排水问题容易导致众多公路路基路面病害,公路施工中必须采取有效的措施进行排水。从而确保高速公路路基路面的稳定性、强度以及安全性。结合某公路施工实例,系统地探讨了排水施工技术措施,同时综合考虑周边环境因素,从整体的角度进行考虑,在满足预期使用要求的基础上,创造出景观上整体协调、综合效益较高的高速公路排水体系。 相似文献
33.
Fuel economy comparison of conventional drive trains series and parallel hybrid electric step vans 总被引:1,自引:0,他引:1
S. B. Han Y. H. Chang Y. J. Chung E. Y. Lee B. Suh A. Frank 《International Journal of Automotive Technology》2009,10(2):235-240
A hybrid electric vehicle (HEV) is a vehicle that combines a conventional propulsion system with an on-board rechargeable
energy storage system to achieve better fuel economy than a conventional vehicle HEVs do not have limited ranges like battery
electric vehicles, which use batteries charged by an external source. The different propulsion power systems may have common
subsystems or components. The objective of this study is to compare the fuel economies of a conventional step van, a series
hybrid electric step van (HESV), and a parallel HESV by calculating the fuel consumption using the ADVISOR software by NREL.
We also showed the results of the vehicles in different driving cycles including the Central Business District bus cycles,
the New York City Cycle, and the US EPA City and Highway cycles. 相似文献
34.
Travel time is an important index for managers to evaluate the performance of transportation systems and an intuitive measure for travelers to choose routes and departure times. An important part of the literature focuses on predicting instantaneous travel time under recurrent traffic conditions to disseminate traffic information. However, accurate travel time prediction is important for assessing the effects of abnormal traffic conditions and helping travelers make reliable travel decisions under such conditions. This study proposes an online travel time prediction model with emphasis on capturing the effects of anomalies. The model divides a path into short links. A Functional Principal Component Analysis (FPCA) framework is adopted to forecast link travel times based on historical data and real-time measurements. Furthermore, a probabilistic nested delay operator is used to calculate path travel time distributions. To ensure that the algorithm is fast enough for online applications, parallel computation architecture is introduced to overcome the computational burden of the FPCA. Finally, a rolling horizon structure is applied to online travel time prediction. Empirical results for Guangzhou Airport Expressway indicate that the proposed method can capture an abrupt change in traffic state and provide a promising and reliable travel time prediction at both the link and path levels. In the case where the original FPCA is modified for parallelization, accuracy and computational effort are evaluated and compared with those of the sequential algorithm. The proposed algorithm is found to require only a piece rather than a large set of traffic incident records. 相似文献
35.
36.
37.
浦梅铁路引入武夷山地区方案研究 总被引:2,自引:0,他引:2
研究目的:通过对浦梅铁路线路在武夷山地区走向方案的研究,考虑工程投资、通道的完整性、货运功能、客运功能、与城市规划的结合、环境影响、地形地质条件等因素,使得实施方案技术经济合理,综合社会效益最佳。选线设计中提供的一些思路,为客货共线快速铁路在困难山区选线设计积累经验。研究结论:深刻分析浦梅线在武夷山地区线路方案的特点及研究思路,确定出合理的推荐方案。通过对走向方案的过程分析,体现了路网、环保、地质、规划、工程数量等对方案选线的影响及重要性。 相似文献
38.
39.
介绍了基于LabVIEW图形化的虚拟仪器设计、构成、特点及其发展现状和前景。根据电容器补偿原理,提出软件设计思路,利用软件对实测的数据进行了分析,提出补偿意见,达到了预期目的。 相似文献
40.