全文获取类型
收费全文 | 4793篇 |
免费 | 109篇 |
专业分类
公路运输 | 1108篇 |
综合类 | 1327篇 |
水路运输 | 1471篇 |
铁路运输 | 336篇 |
综合运输 | 660篇 |
出版年
2024年 | 8篇 |
2023年 | 16篇 |
2022年 | 64篇 |
2021年 | 110篇 |
2020年 | 70篇 |
2019年 | 42篇 |
2018年 | 379篇 |
2017年 | 339篇 |
2016年 | 324篇 |
2015年 | 82篇 |
2014年 | 156篇 |
2013年 | 249篇 |
2012年 | 254篇 |
2011年 | 419篇 |
2010年 | 431篇 |
2009年 | 290篇 |
2008年 | 399篇 |
2007年 | 304篇 |
2006年 | 193篇 |
2005年 | 185篇 |
2004年 | 98篇 |
2003年 | 101篇 |
2002年 | 66篇 |
2001年 | 60篇 |
2000年 | 44篇 |
1999年 | 26篇 |
1998年 | 20篇 |
1997年 | 5篇 |
1996年 | 14篇 |
1995年 | 15篇 |
1994年 | 13篇 |
1993年 | 12篇 |
1992年 | 8篇 |
1991年 | 7篇 |
1990年 | 6篇 |
1989年 | 4篇 |
1988年 | 7篇 |
1987年 | 3篇 |
1986年 | 7篇 |
1985年 | 4篇 |
1984年 | 8篇 |
1983年 | 7篇 |
1982年 | 6篇 |
1981年 | 10篇 |
1980年 | 6篇 |
1979年 | 9篇 |
1975年 | 5篇 |
1974年 | 5篇 |
1973年 | 2篇 |
1972年 | 4篇 |
排序方式: 共有4902条查询结果,搜索用时 265 毫秒
181.
Yui-yip Lau Ka-chai Tam Adolf K. Y. Ng Zhang Jing Jiejian Feng 《Maritime Policy and Management》2018,45(3):403-417
China’s Belt and Road (BR) initiative is expected to facilitate international trade between the countries involved. In this study, we review the special requirements of wine logistics and the market growth potential of wine consumption in China. A model minimizing generalized logistical costs is developed and applied to wine imports in China, so that the best candidate cities in which to locate transport gateways and distribution centers can be identified. Our analysis suggests that the most preferred gateways are Shanghai, Tianjin, Guangzhou, and Hong Kong, which all have similar delivery costs. In comparison, Beijing and Chongqing have much higher delivery costs, mainly because they do not have good access to marine transport and/or efficient domestic distribution networks. For long-distance intercontinental transport of large volumes of wine, marine shipping remains the only viable delivery mode. However, wine distribution within China extensively uses air, road, and water transport. Therefore, cities with excellent multi-modal transport services are better positioned to become wine logistics gateways. Our study also highlights the importance of value-added services and good government support, which are important factors that influence distribution costs and quality. 相似文献
182.
183.
Studying the in-situ stress distribution at a tunnel site is very important to determine surrounding rock characteristics, the engineering design and the construction scheme. By using the multiple linear regression method based on the least square algorithm, the initial geostress field is analyzed and the corresponding regression coefficients are obtained. The ground stress obtained from the proposed back analysis is reasonable and can meet the demands of the engineering applications. From the rockburst risk level distribution diagram, it is speculated that the Wunvfeng tunnel is in the high filed stress area. Field monitoring should be strengthened and emergency plans should be made to cope with the rockburst risks during the construction process. © 2018, Editorial Office of "Modern Tunnelling Technology". All right reserved. 相似文献
184.
In recent years, large shield tunnels with internal double-decked lanes have been developing rapidly in the field of highway tunnels, and prefabricated elements are increasingly adopted in internal structure. Based on the columns-base joint in Zhuguanglu tunnel, which is under construction, 2 full-scale specimens are designed for the quasi-static test, one specimen is connected with grout sleeve splicing and the other is cast in place. The test results show that: the bearing capacity of specimen with grout sleeve splicing is equal to that of cast-in-situ specimen, but its ductility and energy dissipation capacity are worse than that of the cast-in-situ specimen. And for the specimen with grout sleeve splicing, there exists crack concentration on the area above the sleeve. The crack width is too larger in this area. © 2018, Editorial Office of "Modern Tunnelling Technology". All right reserved. 相似文献
185.
186.
In this paper, a new cellular automata model is proposed to simulate the car and bicycle heterogeneous traffic on urban road. To capture the complex interactions between these two types of vehicles, a novel occupancy rule is adopted in the proposed model to consider the variable lateral distances of mixed vehicular traffic. Based on massive simulations, microscopic fundamental diagrams under different bicycle densities are devised. With these, the bicycle's spilling behavior is then investigated and discussed. In order to reflect the interference of a bicycle on a car, the interference transformation from friction state to block state is modeled explicitly. Finally, different simulation results under different occupancy rules indicate that the constant and fixed occupancy rule adopted in the previous studies might lead to overestimation of car flux in the heterogeneous traffic flows with different bicycle densities. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
187.
This paper examines a case study of the SkyCabs system as a way to alleviate some of the traffic problems of Auckland, New Zealand. SkyCabs is an elevated two-way monobeam carrying light eight-seater cabs on tracks on each side of the beam, available on demand, providing fast, pollution-free, unimpeded travel above the footpath with panoramic views of the city. The aim of this study is to investigate the attractiveness of implementing the SkyCabs system to and from Auckland central business district (CBD) and Auckland international airport by examining four variables: different routes, different number of stops/stations, different passenger demand levels, and different number of cabs in the system. The analysis utilizes geographical information system and simulation tools for the various scenarios considered. The results show that it is possible to assess the cost–benefit of alternative routes in terms of those four variables and rate of return on investment. 相似文献
188.
189.
Julie Paquette François Bellavance Jean-François Cordeau Gilbert Laporte 《Transportation》2012,39(3):539-564
In many countries, dial-a-ride services are provided by public authorities to elderly and handicapped people who cannot use
regular transit. Cost minimization is key to running these services, but one can observe a growing interest in quality measurement
and improvement. A first step in improving quality is to define a quality measurement scale specific to dial-a-ride services.
A second step is to incorporate quality measurements in mathematical models that serve as a basis for optimization algorithms.
To this end, an extensive survey of dial-a-ride users was conducted in Longueuil, the largest suburb of Montreal, Canada.
This paper describes the steps of the survey and presents its main conclusions: (1) 56 attributes were identified based on
interviews, (2) the questionnaire developed has proved to be reliable and valid, (3) an exploratory factor analysis allowed
us to determine 13 dimensions of quality in dial-a-ride services, (4) the most important criteria for users were identified,
and (5) population segmenting variables by which subgroups of users can be categorized were also determined. Managerial implications
of our results are also discussed. 相似文献
190.
Bi Yu Chen William H.K. Lam Agachai SumaleeQingquan Li Zhi-Chun Li 《Transportation Research Part A: Policy and Practice》2012,46(3):501-516
To assess the vulnerability of congested road networks, the commonly used full network scan approach is to evaluate all possible scenarios of link closure using a form of traffic assignment. This approach can be computationally burdensome and may not be viable for identifying the most critical links in large-scale networks. In this study, an “impact area” vulnerability analysis approach is proposed to evaluate the consequences of a link closure within its impact area instead of the whole network. The proposed approach can significantly reduce the search space for determining the most critical links in large-scale networks. In addition, a new vulnerability index is introduced to examine properly the consequences of a link closure. The effects of demand uncertainty and heterogeneous travellers’ risk-taking behaviour are explicitly considered. Numerical results for two different road networks show that in practice the proposed approach is more efficient than traditional full scan approach for identifying the same set of critical links. Numerical results also demonstrate that both stochastic demand and travellers’ risk-taking behaviour have significant impacts on network vulnerability analysis, especially under high network congestion and large demand variations. Ignoring their impacts can underestimate the consequences of link closures and misidentify the most critical links. 相似文献