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991.
Rapid urban expansion in China has created both opportunities and challenges for promoting active transport in urban residential communities. Previous studies have shown that the urban form at the city scale has affected active transport in Chinese cities. However, there is less agreement about how the physical and social variations of neighborhood types should be addressed. This research investigates the four most representative neighborhood types found in Chinese cities: traditional mixed-use, slab block work-unit, gated community, and resettlement housing. Household travel diaries conducted in Chengdu in 2016 were analyzed using binary logistic regressions, supplemented by informal onsite interviews. The findings indicate significant variations in the use and accessibility of active transport in each neighborhood type for non-work trips. This suggests that each neighborhood type may need different strategies for promoting active transport: (1) the traditional mixed-use neighborhoods are in need of intensified urban retrofitting projects to reclaim public open space; (2) the work-unit could benefit from comprehensive plans rather than a patchwork of projects; (3) while opening up gated communities can improve porosity across neighborhoods and promote active transport, the more pressing issue may be their inability to keep up with the transportation needs of the residents; and (4) residents of resettlement housing should have better access to employment using transit and non-motorized modes. 相似文献
992.
Xingwen Wu Subhash Rakheja Huichao Wu Sheng Qu Pingbo Wu Huanyun Dai 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2019,57(6):914-934
High magnitude impact loads caused by polygonal wear of the wheels have been associated with in-service failures of structural components of high-speed railways, although the mechanisms leading to wheels’ polygonalisation is not yet fully understood. In this study, a long-term field test programme is undertaken and the data are analysed to gain better understanding of the growth in polygonal wear, and its characteristics and correlation with the axle box acceleration. The field measurements on a high-speed railway involved monitoring of wheels profiles between successive re-profiling of the wheels so as to identify the rate of growth of wear in addition to the axle box acceleration. The data suggested rapid growth in wheel wear, which could be characterised by polygonal wear of nearly 18th and 19th harmonic order. It is further shown that the magnitude of axle box acceleration increased considerably with increasing wear magnitude of the wheel. 相似文献
993.
针对起重机常用的电气传动方案,提出采用矢量控制变频调速是最优方案,它能改善整机的性能,特别是能较好地解决起升机构上使用变频调速的一些关键技术。 相似文献
994.
为探索大数据时代人工智能、大数据等新技术如何应用到交通运输领域中,实现智能交通的重大变革,首先,从信息资源整合、数据智能分析决策、大数据全生命周期的新技术应用、信息主动推送、智能网联汽车等方面提出智能交通的痛点及需求。其次,总结智能视频分析、交通信号控制、智能交通平台应用及智能网联汽车等业务领域研究现状。再次,围绕自然语言处理、计算机视觉、智能化交通信号控制、汽车电子标识、数据湖蓝光存储等新技术,分别从技术突破、业务应用两个方面阐述新技术突破在智能交通领域的应用。最后,提出了大数据时代新技术
在智能交通领域研究方向的建议。 相似文献
995.
居住地是家庭成员日常活动的主要起讫点,迁居会导致家庭日常生活空间重组,进而成为影响成员活动安排和出行模式的关键因素.本文以迁居家庭为研究对象,分别从个体和家庭两个层面分析迁居前后日常活动—出行行为的调整变化,以揭示家庭成员间的交互模式及其内在机理.研究表明:迁居对成员活动—出行行为的影响首先体现在通勤模式调整上,其次是在家务分担上.具体来说,当两个成员均受到职住错位影响时,双方在家务活动安排上交互强烈,家庭内部会通过替代或互助等互动模式来平衡通勤活动所受到的时空制约;当只有一方受到职住错位制约时,双方交互程度进一步降低,家务活动安排上表现出显著性别差异,男方较容易受通勤活动的影响而放弃承担家务活动;当双方均处于职住邻近状态时,双方交互程度最弱,家务活动常采用陪伴或联合等协作方式来完成. 相似文献
996.
997.
The phenomenon of urban sprawl has strong impacts on transport performance and accessibility and causes an increase of air pollution. Effective control of urban sprawl requires an integrated approach comprising urban transport and land-use planning. Current research is insufficient to demonstrate the effects of urban sprawl on travel behavior and air pollution emission. The present paper examines the potential of an integrated approach on space–transport development strategies with the aim of increasing accessibility and reducing air pollution. A combination of space and transport strategies has been simulated for the rapidly expanding city of Surabaya. A comparative analysis of the impact of those cases indicates the promising potential alternatives to minimize the phenomenon. The transport options considered are combinations of Public Transport (PT), comprising Mass Rapid Transit (MRT), Light Rapid Transit (LRT), and Bus Rapid Transit (BRT). The options for urban structure include a compact zone development for the city, as formulated by the city planning agency, and a polycentric city set-up based on a job-housing balance aimed at minimizing the house-job distance. The results indicate that the polycentric city structure has the potential to make public transport work successfully for the city of Surabaya. This city structure creates a trip demand pattern which matches citizens’ PT preferences. Compared to the current situation, the combination of such a city structure with an expansion of PT systems would lead to a considerable improvement of transport performance, i.e. a PT mode share, a mean commute distance, and a significant reduction in emissions. 相似文献
998.
999.
1000.
交流传动牵引变流器的技术发展 总被引:9,自引:7,他引:9
阐述了交流传动牵引变流器的基本电路原理,结合国产DJ型电力机车、NJ1型内燃机车、DWA型地铁工程车等交流传动机车牵引变流器的主要技术参数,对交流传动牵引变流器的技术特点及其发展过程作了较为详细的叙述。 相似文献