全文获取类型
收费全文 | 833篇 |
免费 | 64篇 |
专业分类
公路运输 | 292篇 |
综合类 | 294篇 |
水路运输 | 86篇 |
铁路运输 | 169篇 |
综合运输 | 56篇 |
出版年
2024年 | 6篇 |
2023年 | 12篇 |
2022年 | 19篇 |
2021年 | 23篇 |
2020年 | 31篇 |
2019年 | 24篇 |
2018年 | 24篇 |
2017年 | 24篇 |
2016年 | 34篇 |
2015年 | 29篇 |
2014年 | 69篇 |
2013年 | 50篇 |
2012年 | 91篇 |
2011年 | 87篇 |
2010年 | 53篇 |
2009年 | 61篇 |
2008年 | 56篇 |
2007年 | 51篇 |
2006年 | 55篇 |
2005年 | 33篇 |
2004年 | 20篇 |
2003年 | 10篇 |
2002年 | 9篇 |
2001年 | 11篇 |
2000年 | 4篇 |
1999年 | 1篇 |
1996年 | 3篇 |
1994年 | 2篇 |
1990年 | 3篇 |
1989年 | 1篇 |
1984年 | 1篇 |
排序方式: 共有897条查询结果,搜索用时 109 毫秒
231.
232.
233.
234.
采用动态测速仪测定多个交叉口的瞬时速度、减速度等参数,得到各测点车型分布特性、时段特性,并对瞬时车速进行拟合优度检验,提出当量速度的概念。交叉口的减速度大部分在[0,2]区间内,急刹车的情况较少,当车辆减速度较大时,沥青路面承受较大的水平力,可能出现一次性剪切损坏。 相似文献
235.
Automated driving is gaining increasing amounts of attention from both industry and academic communities because it is regarded as the most promising technology for improving road safety in the future. The ability to make an automated lane change is one of the most important parts of automated driving. However, there has been little research into automated lane change maneuvers, and current research has not identified a way to avoid potential collisions during lane changes, which result from the state variations of the other vehicles. One important reason is that the lane change vehicle cannot acquire accurate information regarding the other vehicles, especially the vehicles in the adjacent lane. However, vehicle-to-vehicle communication has the advantage of providing more information, and this information is more accurate than that obtained from other sensors, such as radars and lasers. Therefore, we propose a dynamic automated lane change maneuver based on vehicle-to-vehicle communication to accomplish an automated lane change and eliminate potential collisions during the lane change process. The key technologies for this maneuver are trajectory planning and trajectory tracking. Trajectory planning calculates a reference trajectory satisfying the demands of safety, comfort and traffic efficiency and updates it to avoid potential collisions until the lane change is complete. The trajectory planning method converts the planning problem into a constrained optimization problem using the lane change time and distance. This method is capable of planning a reference trajectory for a normal lane change, an emergency lane change and a change back to the original lane. A trajectory-tracking controller based on sliding mode control calculates the control inputs to make the host vehicle travel along the reference trajectory. Finally, simulations and experiments using a driving simulator are conducted. They demonstrate that the proposed dynamic automated lane change maneuver can avoid potential collisions during the lane change process effectively. 相似文献
236.
Land border crossings in North America, such as those between Canada and U.S.A., are expected to experience severe imbalance of travel demand and capacity of processors. During peak travel periods, this is already the case at high traffic locations. The land border crossing authorities have to address problems of congestion, national security and environmental impacts in the operation of the existing systems and to continue to address these problems as a part of infrastructure expansion plans. There is a need to adapt the crossing system management in order to accommodate efficiency and productivity‐oriented priority crossing measures. From a methodological perspective, it is a challenge to evaluate the role of priority crossing measures within the complex border crossing system. This paper reports research on modelling priority crossing initiatives. A microsimulation approach was used to model and analyse integrated processors of the Peace Bridge crossing system between Fort Erie (Ontario) and Buffalo (New York) under different scenarios of travel demand, customs processing times, priority crossing and queue jump lanes for automobile and truck traffic. Findings show the extent to which a border crossing system with priority crossing and queue jump lanes is more efficient and productive than one without these innovations. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
237.
《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2012,50(12):1873-1894
This paper presents the application of a novel neuromorphic control strategy for lane change manoeuvres in the highway environment. The lateral dynamics of a vehicle with and without wind disturbance are derived and utilised to implement a control strategy based on the brain limbic system. To show the robustness of the proposed controller, several disturbance conditions including wind, uncertainty in the cornering stiffness, and changes in the vehicle mass are investigated. To demonstrate the performance of the suggested strategy, simulation results of the proposed method are compared with the human driver model-based control scheme, which has been discussed in the literature. The simulation results demonstrate the superiority of the proposed controller in energy efficiency, driving comfort, and robustness. 相似文献
238.
杨丹燕 《电力机车与城轨车辆》2008,31(6)
介绍了长春70%低地板轻轨车辆的主要技术特征,车辆电气系统的主要构成,对车辆的高压系统、牵引系统、制动系统、辅助供电系统、列车网络及故障诊断系统的主要技术特点做了详细的描述。 相似文献
239.
高速公路合流区上匝道混合车流通行能力经验计算法 总被引:2,自引:0,他引:2
研究高速公路合流区上匝道混合车流的通行能力的计算问题。利用已有的高速公路合流区外侧车道交通特征分析结论,推求在外侧车流不同车头时距分布特征下的上匝道混合车流汇合概率模型。运用回归技术和统计方法,建立了加速车道合流点分布概率的实测经验模型。对可接受间隙理论的原型进行了形式上的修正,最终建立高速公路合流区上匝道的混合车流通行能力经验模型,它是主路交通量、匝道交通量、加速车道长度、匝道混合车流比例以及各自的临界间隙和随车时距的函数。最后结合实例介绍经验模型的数值积分求解方法,并证实该经验计算方法具有较高的实效性和可操作性。 相似文献
240.
高速运输对汽车的动力性、制动性和操作稳定性的要求日趋严格,公路设计应有针对性地增加相关安全设施设计。本文以广东下庄自动行车道为例,简要介绍其设计过程,重点利用汽车动力学的观点,对纵断面的设计依据及使用效果进行分析。 相似文献