全文获取类型
收费全文 | 1245篇 |
免费 | 19篇 |
专业分类
公路运输 | 373篇 |
综合类 | 266篇 |
水路运输 | 332篇 |
铁路运输 | 214篇 |
综合运输 | 79篇 |
出版年
2024年 | 1篇 |
2023年 | 4篇 |
2022年 | 12篇 |
2021年 | 33篇 |
2020年 | 26篇 |
2019年 | 13篇 |
2018年 | 17篇 |
2017年 | 23篇 |
2016年 | 18篇 |
2015年 | 47篇 |
2014年 | 64篇 |
2013年 | 50篇 |
2012年 | 99篇 |
2011年 | 84篇 |
2010年 | 53篇 |
2009年 | 71篇 |
2008年 | 66篇 |
2007年 | 105篇 |
2006年 | 110篇 |
2005年 | 75篇 |
2004年 | 57篇 |
2003年 | 44篇 |
2002年 | 25篇 |
2001年 | 34篇 |
2000年 | 33篇 |
1999年 | 25篇 |
1998年 | 24篇 |
1997年 | 13篇 |
1996年 | 7篇 |
1995年 | 6篇 |
1994年 | 7篇 |
1993年 | 7篇 |
1992年 | 1篇 |
1991年 | 2篇 |
1990年 | 3篇 |
1989年 | 2篇 |
1988年 | 3篇 |
排序方式: 共有1264条查询结果,搜索用时 139 毫秒
91.
基于模糊综合评价的职工技术培训效果评估 总被引:1,自引:0,他引:1
针对培训效果评估的实际,提出采用柯克帕特里克培训评估模式,结合模糊综合评价方法,以及一定的评判准则,进行职工技术培训评估,并设计了模型实例,为铁路运输职工技术培训效果评估提供一条新思路。 相似文献
92.
为加强轮机人员对电力系统知识的掌握,根据现代大型集装箱船电力系统的特点,详细介绍了船舶应急电系统受控的逻辑关系,特别指出联络开关的意义和作用,可为船舶电站设计、轮机设备维护管理及故障分析提供指导。 相似文献
93.
《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2012,50(11):795-806
Two typical criteria for good vehicle suspension performance are their ability to provide good road handling and increased passenger comfort. The main disturbance affecting these two criteria is terrain irregularities. Active suspension control systems reduce these undesirable effects by isolating car body motion from vibrations at the wheels. This paper describes fuzzy and adaptive fuzzy control (AFC) schemes for the automobile active suspension system (ASS). The design objective is to provide smooth vertical motion so as to achieve the road holding and riding comfort over a wide range of road profiles. The efficacy of the proposed control schemes is demonstrated via simulations. With respect to the optimal linear quadratic regulator (LQR), it is shown that superior results have been achieved by the AFC. 相似文献
94.
95.
《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2012,50(6):711-733
The traction control system (TCS) might prevent excessive skid of the driving wheels so as to enhance the driving performance and direction stability of the vehicle. But if driven on an uneven low-friction road, the vehicle body often vibrates severely due to the drastic fluctuations of driving wheels, and then the vehicle comfort might be reduced greatly. The vibrations could be hardly removed with traditional drive-slip control logic of the TCS. In this paper, a novel fuzzy logic controller has been brought forward, in which the vibration signals of the driving wheels are adopted as new controlled variables, and then the engine torque and the active brake pressure might be coordinately re-adjusted besides the basic logic of a traditional TCS. In the proposed controller, an adjustable engine torque and pressure compensation loop are adopted to constrain the drastic vehicle vibration. Thus, the wheel driving slips and the vibration degrees might be adjusted synchronously and effectively. The simulation results and the real vehicle tests validated that the proposed algorithm is effective and adaptable for a complicated uneven low-friction road. 相似文献
96.
97.
根据对科技人才考评的原则,提出了科技人才考评指标体系结构模型,并利用Fuzzy方法对科技人才进行综合评价。 相似文献
98.
Sibok Lee Raymond A. Krammes John Yen 《Transportation Research Part C: Emerging Technologies》1998,6(5-6)
This paper documents a fuzzy-logic-based incident detection algorithm for signalized urban diamond interchanges. The model is capable of detecting lane-blocking incidents whose effects are manifested by patterns of deterioration in traffic conditions that require adjustments in signal control strategies. As a component of a real-time traffic adaptive control system for signalized diamond interchanges, the algorithm feeds an incident report (i.e., the time, location, and severity of the incident) to the system's optimization manager, which uses that information to determine the appropriate signal control strategy.The performance of the model was studied using a simulation of an actual diamond interchange. The simulation study evaluated the model's performance in terms of detection rate, false alarm rate, and mean time to detect. The model's performance was encouraging, and the fuzzy-logic-based approach is considered promising. 相似文献
99.
介绍作者设计的面向工业控制与管理一体化的 SASEC- PL C网络 ,涉及网络的拓卜结构内部协议和网络工作流程 ,最后简介内部网络的物理特性 相似文献
100.
本文简单介绍了无功补偿装置的一般应用情况和结构,以及其工作原理。详细介绍了该装置的三大功能及其实现,如控制功能、保护功能、数据处理功能。 相似文献