全文获取类型
收费全文 | 409篇 |
免费 | 0篇 |
专业分类
公路运输 | 230篇 |
综合类 | 23篇 |
水路运输 | 4篇 |
铁路运输 | 91篇 |
综合运输 | 61篇 |
出版年
2022年 | 4篇 |
2021年 | 8篇 |
2020年 | 18篇 |
2018年 | 9篇 |
2017年 | 8篇 |
2016年 | 9篇 |
2015年 | 8篇 |
2014年 | 30篇 |
2013年 | 15篇 |
2012年 | 28篇 |
2011年 | 29篇 |
2010年 | 20篇 |
2009年 | 23篇 |
2008年 | 13篇 |
2007年 | 35篇 |
2006年 | 22篇 |
2005年 | 12篇 |
2004年 | 16篇 |
2003年 | 12篇 |
2002年 | 7篇 |
2001年 | 18篇 |
2000年 | 20篇 |
1999年 | 5篇 |
1998年 | 5篇 |
1997年 | 12篇 |
1996年 | 6篇 |
1995年 | 13篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1991年 | 1篇 |
排序方式: 共有409条查询结果,搜索用时 15 毫秒
311.
312.
汽车轮胎每天都要和粗糙的路面接触,发生磨损自然是在所难免的事情。但是,绝不能因此就对轮胎的磨损掉以轻心,因为可以从轮胎的磨损程度发现汽车隐藏的故障。一般来说,如果汽车没有问题,轮胎的磨损就应该是均匀的;如果磨损不均,那可能就是有问题了。在汽车的行驶过程中,如果操作使用不当或维护保养不及时,将导致轮胎的异常损伤,直接影响汽车的动力性、经济性和各种使用性能的发挥,甚至造成严重的行车事故。汽车轮胎不仅影响整车动力性、经济性和轮胎使用寿命,而且直接影响汽车的操纵稳定性、汽车行驶方向的可控性,关系到人的生命和财产安全。因此,要科学地按技术要求控制轮胎气压,减少或避免轮胎异常磨损,合理维护和正确使用轮胎。 相似文献
313.
基于ADAMS/Car Ride将路桥过渡段的路面不平整模型简化错台型和折线型,同时建立虚拟四柱试验台车辆模型,在此基础上,分析了路面状态和车速对车辆振动的影响。提出的方法可进一步用于研究车辆作用下的路面响应,同时,研究所得到的荷载的相关规律可用于分析车辆动荷载作用下路面的破坏机理。 相似文献
314.
以出口铁路货车KZ1型转向架制动梁滑块磨耗套产品为对象,从产品结构分析、模具设计、注塑机选型、工艺参数确定等方面开展工艺研究.模具型腔采用1模1腔、冷流道、2板模设计,模具四角以圆导柱为动定模导向机构.浇注系统采用盘形浇口进胶方式,以减少熔接痕数量;在分型面上开设排气槽,所有排气槽均与模具外侧联通,以实现良好排气;在产... 相似文献
315.
316.
滚动轮胎瞬态和稳态强迫响应分析 总被引:1,自引:1,他引:0
采用移动载荷的概念,分别推导了点力激励的响应及分布力激励的响应列式,计算了胎体上点在点载荷作用下的时间历程。为轮胎滚动模型提供基础。 相似文献
317.
以自主开发的量产车为例介绍了汽车造型设计的过程及方法;并对国内汽车造型的现状、汽车造型流行趋势进行了分析,同时也阐述了家族式造型设计理念及造型风格的文化内涵。 相似文献
318.
The advancements in communication and sensing technologies can be exploited to assist the drivers in making better decisions. In this paper, we consider the design of a real-time cooperative eco-driving strategy for a group of vehicles with mixed automated vehicles (AVs) and human-driven vehicles (HVs). The lead vehicles in the platoon can receive the signal phase and timing information via vehicle-to-infrastructure (V2I) communication and the traffic states of both the preceding vehicle and current platoon via vehicle-to-vehicle (V2V) communication. We propose a receding horizon model predictive control (MPC) method to minimise the fuel consumption for platoons and drive the platoons to pass the intersection on a green phase. The method is then extended to dynamic platoon splitting and merging rules for cooperation among AVs and HVs in response to the high variation in urban traffic flow. Extensive simulation tests are also conducted to demonstrate the performance of the model in various conditions in the mixed traffic flow and different penetration rates of AVs. Our model shows that the cooperation between AVs and HVs can further smooth out the trajectory of the latter and reduce the fuel consumption of the entire traffic system, especially for the low penetration of AVs. It is noteworthy that the proposed model does not compromise the traffic efficiency and the driving comfort while achieving the eco-driving strategy. 相似文献
319.
A. McNabola B.M. Broderick L.W. Gill 《Transportation Research Part D: Transport and Environment》2009,14(8):567-575
The influence of inter-vehicle spacing on the in-vehicle air pollution exposure of car commuters in heavy traffic conditions was investigated, both experimentally and numerically. An experimental investigation was carried out into the effect, on in-vehicle air pollution exposure, of maintaining a distance of approximately 2 m to the preceding vehicle in congested idling traffic conditions compared to that of an identical vehicle maintaining a distance of approximately 1 m. In-vehicle VOC and PM2.5 concentrations revealed that a 19–31% reduction in exposure at the larger inter-vehicle spacing. A computational fluid dynamics model was calibrated using the experimental data and used to prediction car exposure under different conditions by varying certain key parameters. Agreement between the experimental and predicted data of 82% was achieved. The results show a significant drop in pollutant concentrations occurred within the first 2 m of their emission from the preceding vehicles exhaust. 相似文献
320.
David Lois Mercedes Lpez-Sez 《Transportation Research Part A: Policy and Practice》2009,43(9-10):790-799
Traditionally, urban mobility has been studied from the utilitarian or practical viewpoint, focusing on instrumental motivations and ignoring symbolic and affective aspects that may play a relevant role. The purpose of this work is to analyze from a psychosocial perspective the influence of symbolic, affective, and instrumental motivations on the frequency of car use, taking into account diverse reasons for traveling. From a sample of the Spanish population, participants were 284 people (50.3% female), with a driver’s license, car owners and residents in cities of various sizes, who completed an anonymous questionnaire. The effect of each type of variable was estimated by a structural equation model. Results indicate that people’s affective link with their private vehicle explains 12% of frequency of car use, as a latent variable of different kinds of trips: visiting friends or relatives, going to work or to a study center, going shopping, or to leisure areas. The instrumental advantages associated with cars and thinking that it expresses one’s status predict the affective link with the car. These findings corroborate the relevance of the non-instrumental aspects involved in the selection of the means of transportation. 相似文献