全文获取类型
收费全文 | 212篇 |
免费 | 4篇 |
专业分类
公路运输 | 44篇 |
综合类 | 34篇 |
水路运输 | 70篇 |
铁路运输 | 27篇 |
综合运输 | 41篇 |
出版年
2024年 | 1篇 |
2023年 | 2篇 |
2022年 | 8篇 |
2021年 | 6篇 |
2019年 | 4篇 |
2018年 | 6篇 |
2017年 | 4篇 |
2016年 | 7篇 |
2015年 | 2篇 |
2014年 | 5篇 |
2013年 | 26篇 |
2012年 | 7篇 |
2011年 | 7篇 |
2010年 | 6篇 |
2009年 | 8篇 |
2008年 | 4篇 |
2007年 | 5篇 |
2006年 | 10篇 |
2005年 | 8篇 |
2004年 | 5篇 |
2003年 | 12篇 |
2002年 | 20篇 |
2001年 | 19篇 |
2000年 | 6篇 |
1999年 | 8篇 |
1998年 | 4篇 |
1995年 | 1篇 |
1994年 | 3篇 |
1991年 | 1篇 |
1989年 | 3篇 |
1988年 | 2篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1977年 | 1篇 |
1974年 | 1篇 |
排序方式: 共有216条查询结果,搜索用时 359 毫秒
71.
72.
Gustaaf De Monie 《Maritime Policy and Management》1995,22(3):235-238
Indian ports require substantial physical modernization, but their poor performance can also be attributed to administrative problems. Institutional change is both a necessary condition for privatization and one of its principal benefits. 相似文献
73.
J. Castillo A. P rez De La Blanca J. A. Cabrera A. Sim n 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2006,44(3):207-221
An optical tire contact pressure test bench developed by the IMMa group is described. The measurement system is based on the frustration of total internal reflection (FTIR) of light. The test bench allows performing normal pressure distribution and patch contact shape measurements on passenger car tires. The system is based on the use of a laterally illuminated glass on which the tire leans. Between them a plastic interphase is located that will cause the FTIR of light. A video camera catches the formed shining image through the glass. The brightness level in each pixel of the image can be related to the existing normal pressure. The study of the contact patch provided by the bench makes it possible to characterize tire behaviour under different loading states, inflation pressure, tire defects and toe and camber angles. The bench incorporates a computerized load and control system of the tire operation parameters, an image acquisition module and a data acquisition system that allow monitoring and acting on the experimental variables of interest in the tests such as load on the tire and environmental conditions. A supporting mechanical system incorporated to the bench allows providing the tire with variable toe and camber angles. From the images obtained with this system, the maximum normal pressure points, total force, size and shape of the patch can be determined, which are related to the tire-use conditions. As an application example, results that show the patch size and shape under different load and tire inflation pressures are presented. A further application, which is the use of the system for the detection and study of defective tires is also presented. 相似文献
74.
The Belgian government intends to shift part of its funding away from Antwerp and towards other seaports, particularly Ghent and Zeebrugge. In the long run, this policy change will undoubtedly influence the port choice and probably cause a traffic diversion at the expense of Antwerp. This will have a great influence on the structure of inland transportation.
The impact of port choice on inland transportation is the central theme of this paper. To this end a disaggregated model of the demand for freight transport is constructed. 相似文献
The impact of port choice on inland transportation is the central theme of this paper. To this end a disaggregated model of the demand for freight transport is constructed. 相似文献
75.
P. De Man P. Lemerle P. Mistrot J-Ph Verschueren A. Preumont 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2005,43(2):107-119
This paper investigates the feasibility of a semiactive suspension of the cabin of a fork lift truck as a way of reducing the effect of harmful vibrations on the health of truck drivers. A suspension based on MR fluid dampers has been designed and implemented on an actual vehicle and heuristic control strategy has been developed, which preserves the filtering properties of the passive suspension when the vehicle moves in a straight line with a constant velocity and suppresses the large amplitude pitch and roll motion during turns and braking. Field tests have demonstrated a substantial comfort improvement with respect to the passive suspension, during the braking and turning phases, without any noticeable detrimental effects. 相似文献
76.
随着建筑事业的不断发展,在公路工程施工中对机械设备进行科学合理的维修和养护也逐渐受到重视。对公路养护机械设备维修和维护管理策略进行探讨,从公路养护机械设备出现故障的主要原因入手,分析机械设备的内部问题和外部因素对机械设备的影响,对机械设备维修管理的问题进行分析,提出对公路养护机械设备进行维修和维护的相关管理策略。研究认为,要实现对公路养护机械设备的合理维修和维护,必须使机械设备自身的特点与工程施工相结合,才能找到最合理的维修和维护方法。 相似文献
77.
This paper discusses the importance of Zannetos’ 1966 book for the development of maritime economic thought. The main contributions of the book are recounted, and the empirical work in the book is reviewed. The analysis of the present paper is a citation research on the maritime economics literature that refers to the book. Of the 42 papers in the set, about one-third refers to the book in general. A total of 35 papers refer to one or more elements of the book, with an equal number of references to: (1) the term structure of freight rates; (2) the empirical findings on the form of the supply curve; and (3) on the verification of his results. The general conclusion of the citation analysis is that, apparently, a number of elements of his work are still very valid for current maritime economics thinking, while maritime economists have disregarded several other elements. The latter seems unjustified for some of the business structure observations that are made in the book, such as the notion that the ship is the firm, and the elasticity of expectations. The former observation is the basis for virtually all empirical work in maritime economics that is based on individual contract data (all freight rate analysis is of this nature), and the second is the basis for the analysis of investment behaviour in shipping, investigations of cyclicality and so on. Zannetos can definitely be seen as the initiator of the important field of term structure analysis in maritime economics. In addition to this, there are several topics in the 1966 book that are as yet unexplored, and deserve empirical scrutiny. 相似文献
78.
Marcella Castells Sanabra Juan José Usabiaga Santamaría Francesc Xavier Martínez De Osés 《Maritime Policy and Management》2013,40(1):42-60
Local air pollution is the most relevant externality of maritime transport, and its effects are more acute in urban areas as a result of manoeuvring, hotelling and load/unload activities at ports. This article is intended to assess ships’ local air pollution impact in generally densely populated harbour areas to decide whether alternative power supply measures are feasible. First, an optimized infrastructure investment model is developed to ease implementation and maximize the efficiency of alternative power supply projects. Once target harbours and traffic (ship types) within a national port network have been chosen, a vessel traffic analysis (ship type, tonnage, manoeuvring, and hotelling times) is carried out to quantify and evaluate annual polluting emissions (PM2,5, SO2, NOx, and VOCs) and their externalities. Finally, the assessment model is applied and results of the Spanish port network case study are discussed. The results obtained are significant and bring the possibility of further controlling the ship’s environmental performance at berth. 相似文献
79.
Bruno De Benedetti Paolo Tecchio Sara Rollino Marina Foschia Sonia Pignatelli 《上海交通大学学报(英文版)》2012,17(3):334-336
The present study aims to provide a preliminary overview of the sustainability concept when biomasses conceived for food goals become the raw materials upon which different sectors, such as plastic or energy industry, can develop innovative strategies, according to a so called ??greener?? competitiveness. In the results hereafter presented, the definition of sustainability perspectives, according to the use of a life cycle assessment (LCA) approach, will be described for maize use as raw material in different sectors. The current biopolymer industry and conventional biofuel technologies, the so called first-generation biofuels, are the more and more in competition with the food sector. The presented environmental evaluation, in terms of air emissions, energy and water consumption, is useful in order to understand the sustainability of a bio-sourced product, in comparison with the equivalent item produced by fossil fuels. 相似文献
80.
有轨电车和轻轨车辆的防碰撞性 总被引:3,自引:0,他引:3
为提高有轨电车和轻轨车辆的防碰撞性,研制了防碰撞的车体结构,并进行了试验验证。 相似文献