全文获取类型
收费全文 | 2950篇 |
免费 | 88篇 |
专业分类
公路运输 | 945篇 |
综合类 | 714篇 |
水路运输 | 725篇 |
铁路运输 | 500篇 |
综合运输 | 154篇 |
出版年
2024年 | 3篇 |
2023年 | 19篇 |
2022年 | 64篇 |
2021年 | 85篇 |
2020年 | 85篇 |
2019年 | 38篇 |
2018年 | 62篇 |
2017年 | 73篇 |
2016年 | 63篇 |
2015年 | 95篇 |
2014年 | 148篇 |
2013年 | 191篇 |
2012年 | 216篇 |
2011年 | 201篇 |
2010年 | 223篇 |
2009年 | 234篇 |
2008年 | 234篇 |
2007年 | 253篇 |
2006年 | 210篇 |
2005年 | 156篇 |
2004年 | 64篇 |
2003年 | 53篇 |
2002年 | 53篇 |
2001年 | 51篇 |
2000年 | 41篇 |
1999年 | 34篇 |
1998年 | 21篇 |
1997年 | 9篇 |
1996年 | 12篇 |
1995年 | 17篇 |
1994年 | 3篇 |
1993年 | 6篇 |
1992年 | 5篇 |
1991年 | 2篇 |
1990年 | 5篇 |
1988年 | 1篇 |
1986年 | 2篇 |
1984年 | 1篇 |
1976年 | 1篇 |
1973年 | 4篇 |
排序方式: 共有3038条查询结果,搜索用时 185 毫秒
231.
Plates form one of the basic elements of structures. Land-based structures may be subjected to air blast loads during combat environment or terrorist attack, while marine structures may be subjected to either air blast by the attack of a missile above the water surface or an underwater explosion by the attack of a torpedo or a mine or a depth charge and an aircraft structure may be subjected to an in-flight attack by on-board explosive devices. Furthermore, gas explosion occurs in offshore installations and industries. This review focuses on the phenomenological evolution of blast damage of plates. 相似文献
232.
Zhenfeng Wang Mingming Dong Yechen Qin Yongchang Du Feng Zhao 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2017,55(3):371-398
This paper provides a new method to solve the problem of suspension system state estimation using a Kalman Filter (KF) under various road conditions. Due to the fact that practical road conditions are complex and uncertain, the influence of the system process noise variance and measurement noise covariance on the estimation accuracy of the KF is first analysed. To accurately estimate the road condition, a new road classification method through the vertical acceleration of sprung mass is proposed, and different road process variances are obtained to tune the system’s variance for the application of the KF. Then, road classification and KF are combined to form an Adaptive Kalman Filter (AKF) that takes into account the relationship of different road process noise variances and measurement noise covariances under various road conditions. Simulation results show that the proposed AKF algorithm can obtain a high accuracy of state estimation for a suspension system under varying International Standards Organisation road excitation levels. 相似文献
233.
234.
ABSTRACTe-Transformation in container ports means port organization-wide innovative transformation encompassing internal and external value chains based on information and communication technology. There is a considerable theoretical literature on the impact of e-Transformation on business performance, but there is very little empirical study on its effectiveness in ports. The objective of this paper is to empirically investigate how e-Transformation in container port management can influence customer satisfaction and port competitiveness. The findings reveal that e-Transformation in container ports can affect customer satisfaction and port competitiveness through e-Workplace, customer relationship management and security, implying that container ports should make every effort to focus on e-transformation in these critical areas. Due to limited empirical studies in this area, the findings have provided an empirical support for the importance of e-Transformation in container terminal management and shed more light on how e-Transformation can affect customer satisfaction and port competitiveness. 相似文献
235.
A radio frequency identification (RFID) yoking proof scheme can generate proofs of simultaneous presence of two tags in the
range of a specified reader so that an off-line verifier can verify the proofs later. This proof has found several interesting
applications. However, many existing RFID yoking schemes are vulnerable to replay attacks. To overcome the weaknesses, Cho
et al. proposed a new RFID yoking proof protocol and a new grouping protocol. Unfortunately, Cho et al.’s schemes are still
vulnerable to replay attacks. In this paper, in addition to demonstrating weaknesses, we further discuss the rationale behind
these weaknesses to provide a guide line for designing secure RFID yoking schemes. Based on the guide line, we propose a new
RFID yoking scheme and a new RFID grouping scheme. Performance evaluation shows that our scheme outperforms its counterparts. 相似文献
236.
237.
UITP公共交通国际联会成立于1885年,总部设在比利时的布鲁塞尔.该协会将在2010年迎来其成立125周年纪念日。在过去的125年.UITP致力于发展城市的可持续运转及更好的公共交通。高效的公共交通意味着市民更高的生活质量和可续发展的未来。UITP涉及公共交通的各个方面.包括地铁、公共汽车、轻轨、城铁及区域铁路、郊区铁路、水路运输和出租车等。该联会在全球90多个国家共有约3200余名会员,是开展国际合作,商业发展和信息分享的平台。UITP根据不同的地区、公共交通界别、 相似文献
238.
239.
对舰载信息系统数据融合攻击分析 总被引:1,自引:0,他引:1
针对对舰载信息系统的攻击,分析了系统的易损性,提出对数据融合系统的攻击类型,给出了攻击矩阵,并对攻击效果作了简单定性分析。 相似文献
240.
南宁膨胀土胀缩性模糊评判分析 总被引:3,自引:3,他引:0
提出了利用土的密度、液限、塑限、液性指数、塑性指数和自由膨胀率等6项指标来判别南宁膨胀土胀缩性等级的模糊数学定量评判方法,对6项指标与胀缩总率进行了相关关系分析,用其相关系数来确定相应的权重值,建立了相应的模糊数学评判模型,并用实例对所建的模糊数学评判模型进行了验证,其结果与实测结果相吻合。 相似文献