全文获取类型
收费全文 | 2281篇 |
免费 | 159篇 |
专业分类
公路运输 | 588篇 |
综合类 | 854篇 |
水路运输 | 551篇 |
铁路运输 | 329篇 |
综合运输 | 118篇 |
出版年
2024年 | 12篇 |
2023年 | 15篇 |
2022年 | 38篇 |
2021年 | 50篇 |
2020年 | 60篇 |
2019年 | 38篇 |
2018年 | 50篇 |
2017年 | 54篇 |
2016年 | 56篇 |
2015年 | 101篇 |
2014年 | 161篇 |
2013年 | 151篇 |
2012年 | 197篇 |
2011年 | 215篇 |
2010年 | 147篇 |
2009年 | 123篇 |
2008年 | 141篇 |
2007年 | 215篇 |
2006年 | 185篇 |
2005年 | 123篇 |
2004年 | 72篇 |
2003年 | 62篇 |
2002年 | 32篇 |
2001年 | 37篇 |
2000年 | 34篇 |
1999年 | 23篇 |
1998年 | 14篇 |
1997年 | 11篇 |
1996年 | 7篇 |
1995年 | 6篇 |
1994年 | 3篇 |
1993年 | 2篇 |
1992年 | 2篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1987年 | 1篇 |
排序方式: 共有2440条查询结果,搜索用时 15 毫秒
51.
Fuzzy-logic applied to yaw moment control for vehicle stability 总被引:6,自引:0,他引:6
B. L. Boada M. J. L. Boada V. Dí az 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2005,43(10):753-770
In this paper, we propose a new yaw moment control based on fuzzy logic to improve vehicle handling and stability. The advantages of fuzzy methods are their simplicity and their good performance in controlling non-linear systems. The developed controller generates the suitable yaw moment which is obtained from the difference of the brake forces between the front wheels so that the vehicle follows the target values of the yaw rate and the sideslip angle. The simulation results show the effectiveness of the proposed control method when the vehicle is subjected to different cornering steering manoeuvres such as change line and J-turn under different driving conditions (dry road and snow-covered). 相似文献
52.
Fred Wegman 《国际交通安全学会研究报告》2017,40(2):66-71
Estimates by the World Health Organization suggest that, on a yearly basis, road crashes kill 1.25 million people—nearly 3400 road fatalities per day—and injure up to 50 million. Traffic injuries are not equally spread over the world, however; some countries are hit harder than others, and the chance of being killed in a road crash depends on where one lives. Almost 90% of all traffic casualties occur in low- and middle-income countries (LMIC). Globally, the number of fatalities per 100,000 population (mortality rate) ranges from less than 3 to almost 40. The rate is less than 9 in high-income countries (HIC) but averages around 20 in LMIC, with the African region demonstrating the highest rate (26.6). While road safety trends have been positive in HIC over the last few decades, trends in LMIC are not telling a positive story: road fatalities are expected to increase to almost 2 million road fatalities per year by 2020.The United Nations has adopted several resolutions on road safety and proposes actions to tackle the global road safety crisis. Considering the current level of road safety to be unacceptable, the UN has taken several initiatives. One effort, the Decade of Action for Road Safety 2011–2020, has generated substantial activity around the world over the last couple of years. Furthermore, it is very encouraging that the UN included road safety in the Sustainable Development Goals that it laid out in September 2015. Road safety is part of the public health agenda and the urban development agenda. Measured in “real actions,” however, the responses so far from the overall global community and individual countries do not suggest that we are already on the right track to bringing down the death toll on roads.The future of road safety is uncertain and definitely not the same for all regions of the world. Countries with a mature road safety approach and an ambition to make further progress are expected to move in the direction of a pro-active approach: a Safe System approach. It is reported that many LMIC, meanwhile, are on the brink of designing road safety strategies and implementing action plans. The international community is willing to support LMIC, but LMIC cannot simply copy successful HIC strategies because local circumstances differ. The principles of successful HIC strategies are applicable, but the priorities and action plans should take root in and align with local conditions. 相似文献
53.
针对路堑高边坡锚固后的稳定性评价,基于模糊性与层次性构建锚固路堑高边坡稳定性2级模糊综合评判模型。根据不同类评价指标的取值方法及隶属度函数选取原则,建立统一的隶属度确定方法,采用三角模糊数互补判断矩阵排序方法确定权向量,以体现评价指标重要程度比较的不确定性。引入非线性模糊算子,以消除个别影响因素不利时对结果的突出影响,使评价结果能更真实地反映工程实际状况。以京新高速公路路堑高边坡稳定性评价为应用实例,验证该模型的可行性与合理性。 相似文献
54.
55.
56.
57.
58.
主导产业理论对区域汽车产业战略选择的挑战 总被引:1,自引:0,他引:1
在我国经济发展中,确定汽车产业是主导产业是十分重要的。目前在各省经济界对汽车产业是否为支柱产业,是否为主导产业有不同的意见。从理论和实践层面,从产业间产业结构演变规律和汽车业自身发展规律入手,说明了汽车产业在我国国民经济发展中的主导作用。 相似文献
59.
介绍了模糊综合评价法的数学原理,建立航道航行危险度评价模型,并对长江武汉段的航行危险度进行了综合评价。 相似文献
60.
“任务驱动教学法”在外贸英语函电教学中的应用 总被引:3,自引:0,他引:3
徐琼 《浙江交通职业技术学院学报》2008,9(3):61-65
“任务驱动教学法”是以学生为主体,以教师为主导,通过发挥语言的交际功能解决实际问题的教学方法。将“任务驱动教学法”引入针对性、实践性强的外贸英语函电课堂可以让学生在完成任务的过程中掌握并巩固相关的知识要点,同时也有利于培养学生运用英语解决实际问题的能力。本文对“任务驱动教学法”在外贸英语函电教学中的应用进行了探讨。 相似文献