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361.
针对新旧编办及其配套定额,结合工程实例就人、机、材、费率4项指标及建设单位管理费的取费基数进行对比分析,分析其对工程造价的影响。 相似文献
362.
道路交通网络脆弱性评估研究现状与展望 总被引:1,自引:0,他引:1
道路交通网络脆弱性评估是当前路网研究中新的热点和难点问题,识别路网脆弱性并进行有效的管理是应对交通系统危机情况的重要课题,它引起了学者们的广泛关注,本文主要针对当前路网脆弱性评估研究进行梳理和展望. 首先对路网脆弱性的概念进行了归纳总结,讨论了不同学者对路网脆弱性概念的共识和分歧. 其次分析了路网脆弱性与路网可靠性之间的联系和区别. 然后对当前路网脆弱性的评估方法进行了分类分析,将路网脆弱性的评估方法分为基于特定场景评估法、基于特定战略评估法、基于仿真的评估方法和数学模型评估方法四大类. 最后指出了路网脆弱性未来的研究方向. 相似文献
363.
加强船舶燃油加装管理的关键措施分析 总被引:1,自引:0,他引:1
文章结合工作实践,从船舶燃油加装工作的主要环节入手,提出了加强船舶燃油加装工作管理的关键措施:在燃油加装前认真做好充分的准备工作;在燃油加装时严格把好加装过程关;在燃油加装完毕后把好数量核实关与新油使用关。 相似文献
364.
365.
详细介绍了青冈隧道的施工工艺和方法,并对其特点和作用进行了总结,为今后我国隧道建设施工工艺和方法的选择提供参考。 相似文献
366.
Wave impact underneath horizontal decks 总被引:1,自引:0,他引:1
The problem of water impact on a fixed horizontal platform deck from regular incident waves was studied. Two-dimensional potential flow was assumed, and the resulting boundary-value problem was solved by three alternative numerical methods, a method based on a generalization of the impact theory by Wagner, and two different nonlinear boundary-element methods. The Wagner-based method used a von Karman approach during the water exit phase, i.e., when the wetted surface decreases. Experiments of the impact on an idealized platform deck have been performed to validate the theory. Comparisons show that the Wagner-based method yields good results for the water entry phase, when the wetted deck area increases, but poor results when the wetted area diminishes. The boundary-element methods compare well with experiments for the entire impact process. A Kutta condition is necessary at the aft body–free surface intersection during water exit and when the flow separates from the aft edge. Gravity effects matter for the water exit phase. 相似文献
367.
沈阳市东西快速干道工程为减少满堂支架施工对路口交通的影响 ,同时 ,也为了保证整个高架桥梁高一致 ,决定采用钢 -混凝土组合结构。针对该结构的负弯矩区桥面板易引起开裂的问题 ,提出各种处理方法 ,并据此予以结构设计。 相似文献
368.
A computerized household activity scheduling survey 总被引:7,自引:6,他引:1
Household activity scheduling is widely regarded as the underlying mechanism through which people respond to emerging travel
demand management policies. Despite this, very little fundamental research has been conducted into the underlying scheduling
process to improve our understanding and ability forecast travel. The experimental survey approach presented in this paper
attempts to fill this gap. At the core of the survey is a Computerized Household Activity Scheduling (CHASE) software program.
The program is unique in that it runs for a week long period during which time all adult household members login daily to
record their scheduling decisions as they occur over time. An up-front interview is used to define a household's activity
agenda and mode availability. A sample of 41 households (66 adults and 14 children) was used to assess the performance of
the survey. Analysis focuses on times to completion, daily scheduling steps, activity-travel patterns, and scheduling time
horizons. Overall, the results show that the computer-based survey design was successful in gathering an array of information
on the underlying process, while minimizing the burden on respondents. The survey was also capable of tracing traditionally
observed activity-travel outcomes over a multi-day period with minimal fatigue effects. The paper concludes with a detailed
discussion on future survey design, including issues of instrument bias, use of the Internet, and improved tracing of spatial
behaviour. Future use of the survey methodology to enhance activity-travel diary surveys and stated responses experiments
is also discussed.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
369.
In this paper a cost frontier model is estimated for an eleven-year panel of Norwegian bus companies (1136 company-year observations) using the methodology proposed by Battese and Coelli (1995). The main objective of the paper is to investigate to what extent different type of regulatory contracts affect company performance. The panel model proposed by Battese and Coelli (1995) allow for year/company specific efficiency measures to be estimated. Thus, unobservable network or other time invariant characteristic of the operating environment can be controlled for by analyzing the dynamics of measured productivity across time for firms regulated under different types of contracts, rather than relying solely on variations across companies during one time period. Therefore, the paper offers methodological and data advantages over previous work on this subject. The main and robust result of the paper is that the adoption of a more high-powered scheme based on a yardstick type of regulation significantly reduces operating costs. The results contained in this paper thus confirms theoretical predictions regarding the incentive properties of high powered incentive schemes and in particular the dynamic benefits of yardstick competition. 相似文献
370.
预应力锚索框架型地梁的内力计算 总被引:1,自引:0,他引:1
提出了预应力锚索框架型地梁内力的一种计算方法,即把框架地梁分解成单梁,按温克尔(Winkler)假定计算各单梁的内力,由此进行框架地梁的尺寸和配筋设计。在内力计算中同时考虑框架地梁的锚索张拉阶段和工作阶段。通过实际工程说明了计算方法。 相似文献