全文获取类型
收费全文 | 2839篇 |
免费 | 26篇 |
专业分类
公路运输 | 505篇 |
综合类 | 904篇 |
水路运输 | 852篇 |
铁路运输 | 204篇 |
综合运输 | 400篇 |
出版年
2024年 | 2篇 |
2023年 | 2篇 |
2022年 | 20篇 |
2021年 | 34篇 |
2020年 | 25篇 |
2019年 | 10篇 |
2018年 | 347篇 |
2017年 | 296篇 |
2016年 | 267篇 |
2015年 | 29篇 |
2014年 | 30篇 |
2013年 | 49篇 |
2012年 | 118篇 |
2011年 | 270篇 |
2010年 | 279篇 |
2009年 | 117篇 |
2008年 | 265篇 |
2007年 | 209篇 |
2006年 | 105篇 |
2005年 | 123篇 |
2004年 | 72篇 |
2003年 | 74篇 |
2002年 | 34篇 |
2001年 | 17篇 |
2000年 | 16篇 |
1999年 | 14篇 |
1998年 | 9篇 |
1997年 | 6篇 |
1996年 | 1篇 |
1995年 | 6篇 |
1994年 | 9篇 |
1993年 | 1篇 |
1991年 | 3篇 |
1989年 | 3篇 |
1984年 | 3篇 |
排序方式: 共有2865条查询结果,搜索用时 31 毫秒
1.
介绍了智能化轨道快运系统的技术特点及优势,分析了建成区道路拓宽困难、道路交通流量大、用地空间有限等现实条件,并从线路敷设、路权方式、车站设置等方面讨论了智能化轨道快运系统规划的相关内容.以重庆市南滨路智能化轨道快运系统线路为应用案例提出规划建议. 相似文献
2.
PANG Yong-jie YOU Guang-xin 《船舶与海洋工程学报》2005,4(4):1-6
Oceanographic survey, or other similar applications should be the applications of multiple AUVs. In this paper, the skill & simulation based hybrid control architecture (S^2BHCA) as the controller's design reference was proposed. It is a multi-robot cooperation oriented intelligent control architecture based on hybrid ideas. The S^2BHCA attempts to incorporate the virtues of the reactive controller and of the deliberative controller by introducing the concept of the "skill". The additional online task simulation ability for cooperation is supported, too. As an application, a multiple AUV control system was developed with three "skills" for the MCM mission including two different cooperative tasks. The simulation and the sea trials show that simple task expression, fast reaction and better cooperation support can be achieved by realizing the AUV controller based on the S^2BHCA. 相似文献
3.
由于Windows平台图形界面的易操作,使得在各行各业得到迅速的普及。这在工业控制领域也不例外,但是由于Windows操作系统在大部分情况下是以队列形式工作的,使得在Windows下实现实时控制成为了难题。利用多媒体时钟可以很好地实现Windows实时控制。 相似文献
4.
5.
Shogo Nakasumi Katsuyuki Suzuki Daiji Fujii Hideomi Ohtsubo 《Journal of Marine Science and Technology》2003,7(4):180-188
This article presents a mixed method of analyzing shell elements and solid elements using the overlaying mesh method. In
the structural design of a ship's hull, the shell elements are used for the global model. However, the solid elements are
necessary to analyze the stress concentration zones or the vicinity of a crack. In such cases, the models are analyzed using
zooming analysis, in which the results of a global model analysis are transferred to a local model analysis by imposing boundary
conditions. This method is more advantageous than zooming analysis in terms of the accuracy of the solution and the modeling
flexibility. Some examples of a plate model with a cracked surface or with a projection are shown in order to demonstrate
the effectiveness of the method.
Received: August 6, 2002 / Accepted: November 25, 2002
Address correspondence to: S. Nakasumi (sumi@nasl.t.u-tokyo.ac.jp)
Updated from the Japanese original, which won the 2002 SNAJ prize (J Soc Nav Archit Jpn 2001;189:219–224; and 190:655–662) 相似文献
6.
宫永杰 《筑路机械与施工机械化》1993,10(4):18-20
本文论述了沥青输送管路采用保温技术的必要性及采用导热油为热载保温技术的优点对导热 (?)保温筑路结构的关键部位进行了设计。 相似文献
7.
ZHU Hai-tao ZHANG Xu ZHANG Jia-tai HU Sheng-haiCollege of Mechanical Electrical Engineering Harbin Engineering University Harbin China 《船舶与海洋工程学报》2002,1(2):62-65
In this paper, a smart crank and slider mechanism is analyzed mostly from a dynamic view. By means of dynamic explicit finite element method, 3D nonlinear structure is simulated. It is proved that the mechanism can effectively accomplish smart movement prescribed. And in order to ensure reciprocal movement with higher frequency, measures should be taken to avoid over heating of parts. Compared with internal energy, kinetic energy of total rigid body is dominating, and Y direction equivalent rigid velocity is much higher than X direction velocity. Equivalent rigid velocity of all parts is consistent with respective movement condition. For both energy and velocity, slider effect is dominating. Three direction equivalent inertia force oscillates. Force amplitude in Y -direction is comparitively the greatest. 相似文献
8.
This paper presents the results of an investigation into temporal determinants of maritime accidents based on a data-set obtained from the proceedings of formal inquiries in the former German Democratic Republic (GDR). The results show that there is no statistically significant outcome between the probability for an accident and the time of watch. Thus the results do not confirm previous studies, which reported significant time of day effects.The outcome of this study indicates that marine inquiries can provide useful data for an analysis of underlying causes of maritime accidents. It is suggested that accident inquiries should be extended into the area of watch systems employed and should record the hours of work and of rest of the officers on the watch involved in a maritime accident. 相似文献
9.
C. Julian Parker 《WMU Journal of Maritime Affairs》2003,2(2):99-113
This article is in three parts. The first covers the historical development of qualifying associations. The second covers the particular role of maritime institutions that include The Royal Institution of Naval Architects, The Institute of Marine Engineering Science and Technology and The Nautical Institute. The third and final section considers the future for maritime professional associations in the context of international shipping. 相似文献
10.