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301.
针对检修所配置的转辙机测试台功能单一,无法满足对所有系列转辙机的测试,特别是对双机牵引类型转辙设备无测试手段的问题,阐述了智能型转辙机通用测试台的功能、关键技术和系统组成。 相似文献
302.
分析了空间电压矢量脉宽调制(SVPWM)逆变器死区效应产生的原因及影响,根据死区效应及SVPWM的特点提出了电压补偿法。该方法无需增加硬件,实用性较强。仿真和实验结果验证了该方法的有效性。 相似文献
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底盘装配支撑应用于商用汽车底盘装配与工程机械车辆底盘装配,属于装配线附属工装设施。底盘装配支撑结构的适用性、可靠性、耐久性关系到底盘装配线的运行安全与运行效率。文章结合公司在建底盘装配线工艺验证问题整改,对底盘装配支撑结构进行优化,开发出一种适用于驱动桥桥包支撑的实用新型支撑结构。 相似文献
304.
《铁道标准设计通讯》2016,(12):145-148
地铁车辆段检修库中移动式架车机是车体与转向架分解组装以及车底电器、制动等模块拆装的必备设备,移动式架车机以其适用车型广、组合灵活、成本低的特点,得到广泛应用,而移动式架车机要想实现上述功能,需要分析研究与之配套设施的工艺特点。提出移动式架车机在检修库中采用有检查坑和无检查坑的布置方案,通过分析总结后,认为临修库中设置移动式架车机时,采用无检查沟的形式,在架修库设置移动式架车机时,采用有检查坑的形式。 相似文献
305.
文章以郑西客运专线渭河特大桥工程为例,介绍了大型箱梁支架预压的工艺流程、预压荷载、加载范围及加载操作过程,提出了在加载过程操作中应注意的问题,为连续箱梁支架预压施工提供参考。 相似文献
306.
The ever-increasing use of cars is a big problem in metropolitan areas. To manage the traffic stream and alleviate air pollution,
most metropolitan governments are attempting to discourage the use of cars. Nevertheless, the results have not been satisfactory.
It is well known that normal-choice riders choose their travel mode based on utility, which is determined by mode-specific
impedances and individual characteristics. On the other hand, this study focuses on identifying car-dependent commuters who
tend to keep driving cars regardless of the circumstances they are confronted with. For this study, psychometric factors characterizing
car-dependent commuters were investigated. However, the performance of the mode-choice model was not sufficiently enhanced
despite incorporation of the psychometric factors. The performance improved considerably when the car-dependent commuters
were excluded. Based on psychometric factors, the support vector machine successfully separated the car-dependent commuters
from normal-choice riders.
相似文献
Keemin SohnEmail: |
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Accurate vehicle self-localization is significant for autonomous driving. The localization techniques based on Global Navigation Satellite System (GNSS) cannot achieve the required accuracy in urban canyons. On the other hand, simultaneous localization and mapping (SLAM) methods suffer from the error accumulation problem. State-of-the-art localization approaches adopt 3D Light Detection and Ranging (Lidar) to observe the surrounding environment and match the observation with a priori known 3D point cloud map for estimating the position of the vehicle within the map. However, storing the massive point cloud needs immense storage on the vehicle, or it should be stored on servers, which makes the simultaneous downloading of the map by multiple vehicles another challenge. In this study, rather than employing the point cloud directly as the prior map, we focus on the abstract map of buildings, which is easy to extract, and at the same time apparently observable by Lidar. More especially, we proposed vehicle localization methods based on two different abstract map formats representing urban areas. The first format is the multilayer 2D vector map of building footprints, which represents the building boundaries using vectors (lines). The second format is the planar surface map of buildings and ground. These map formats share the same idea that the uncertainty (deviation) of each vector or planar surface is calculated and included in the map. Later in the localization phase, the observed data from Lidar is matched with the abstract map to obtain the precise location of the vehicle. Experiments conducted in a dense urban area of Tokyo show that even though we significantly shrank the map size, we could preserve the mean error of the localization. 相似文献