全文获取类型
收费全文 | 790篇 |
免费 | 11篇 |
专业分类
公路运输 | 153篇 |
综合类 | 113篇 |
水路运输 | 319篇 |
铁路运输 | 51篇 |
综合运输 | 165篇 |
出版年
2024年 | 3篇 |
2023年 | 6篇 |
2022年 | 24篇 |
2021年 | 22篇 |
2020年 | 34篇 |
2019年 | 9篇 |
2018年 | 27篇 |
2017年 | 30篇 |
2016年 | 37篇 |
2015年 | 46篇 |
2014年 | 56篇 |
2013年 | 58篇 |
2012年 | 44篇 |
2011年 | 47篇 |
2010年 | 34篇 |
2009年 | 35篇 |
2008年 | 35篇 |
2007年 | 48篇 |
2006年 | 49篇 |
2005年 | 30篇 |
2004年 | 22篇 |
2003年 | 22篇 |
2002年 | 22篇 |
2001年 | 14篇 |
2000年 | 12篇 |
1999年 | 7篇 |
1998年 | 3篇 |
1997年 | 6篇 |
1996年 | 4篇 |
1995年 | 8篇 |
1994年 | 3篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1990年 | 1篇 |
排序方式: 共有801条查询结果,搜索用时 312 毫秒
61.
本船作为车客渡船具有多用途、多任务的特点,适应性强.该文从型线设计、总体布置、稳性计算等方面,概要介绍了本船的一些设计特点. 相似文献
62.
63.
介绍了丰田凌志400型轿车安全气囊的组成、工作原理、故障代码的读取和清除,以及安全气囊检修的注意事项。 相似文献
64.
65.
采用计算流体动力学(CFD)方法,用AIRPAK软件对10000TEU级集装箱船中的一个货舱在不同工况下的舱内通风效果进行模拟,从而合理的选择风机,达到最优化设计的目的。 相似文献
66.
67.
68.
系统化取装流程作业线因其诸多优点在港口散货码头广泛应用。但因移舱对生产有一定影响。为此进行了改造,提出了优化装卸工艺的解决方案和实施方案的步骤。改造后,取得了节能、增效的效果。 相似文献
69.
Michiel C.J. Bliemer John M. Rose 《Transportation Research Part A: Policy and Practice》2011,45(1):63-79
Discrete choice experiments are conducted in the transport field to obtain data for investigating travel behaviour and derived measures such as the value of travel time savings. The multinomial logit (MNL) and other more advanced discrete choice models (e.g., the mixed MNL model) have often been estimated on data from stated choice experiments and applied for planning and policy purposes. Determining efficient underlying experimental designs for these studies has become an increasingly important stream of research, in which the objective is to generate stated choice tasks that maximize the collected information, yielding more reliable parameter estimates. These theoretical advances have not been rigorously tested in practice, such that claims on whether the theoretical efficiency gains translate into practice cannot be made. Using an extensive empirical study of air travel choice behaviour, this paper presents for the first time results of different stated choice experimental design approaches, in which respective estimation results are compared. We show that D-efficient designs keep their promise in lowering standard errors in estimating, thereby requiring smaller sample sizes, ceteris paribus, compared to a more traditional orthogonal design. The parameter estimates found using an orthogonal design or an efficient design turn out to be statistically different in several cases, mainly attributed to more or less dominant alternatives existing in the orthogonal design. Furthermore, we found that small designs with a limited number of choice tasks performs just as good (or even better) than a large design. Finally, we show that theoretically predicted sample sizes using the so-called S-estimates provide a good lower bound. This paper will enable practitioners in better understanding the potential benefits of efficient designs, and enables policy makers to make decisions based on more reliable parameter estimates. 相似文献
70.
Much Ado about Nothing? - An analysis of economic impacts and ecologic effects of the EU-emission trading scheme in the aviation industry 总被引:1,自引:0,他引:1
Jan Vespermann Andreas Wald 《Transportation Research Part A: Policy and Practice》2011,45(10):1066-1076
From 2012 on, all CO2 emissions from flights departing from or arriving at airports within the European Union have to be offset. We analyze the economic and ecological impacts that are caused by an inclusion of the aviation industry into the proposed emissions trading scheme (ETS). Building on the now fixed system design we employ a simulation model to estimate the impacts of the scheme. Our results indicate that financial impacts are highly dependant on external settings, such as allowance prices and demand growth. We show that the financial burden on the aviation industry will be rather modest in the first years after the introduction of the system and therefore induce only low competition distortions. Likewise, emission reductions within air transportation will be comparably low. While aviation will induce a decline of emissions in other sectors, significant absolute reductions within air transportation can only be reached by a more restrictive system design. 相似文献