全文获取类型
收费全文 | 281篇 |
免费 | 1篇 |
专业分类
公路运输 | 63篇 |
综合类 | 90篇 |
水路运输 | 99篇 |
铁路运输 | 25篇 |
综合运输 | 5篇 |
出版年
2024年 | 1篇 |
2023年 | 4篇 |
2022年 | 4篇 |
2021年 | 2篇 |
2020年 | 6篇 |
2019年 | 5篇 |
2018年 | 10篇 |
2017年 | 5篇 |
2016年 | 2篇 |
2015年 | 4篇 |
2014年 | 6篇 |
2013年 | 9篇 |
2012年 | 18篇 |
2011年 | 9篇 |
2010年 | 11篇 |
2009年 | 16篇 |
2008年 | 12篇 |
2007年 | 15篇 |
2006年 | 15篇 |
2005年 | 21篇 |
2004年 | 18篇 |
2003年 | 18篇 |
2002年 | 12篇 |
2001年 | 12篇 |
2000年 | 11篇 |
1999年 | 9篇 |
1998年 | 7篇 |
1997年 | 5篇 |
1996年 | 2篇 |
1995年 | 1篇 |
1994年 | 3篇 |
1992年 | 1篇 |
1991年 | 4篇 |
1990年 | 1篇 |
1989年 | 2篇 |
1985年 | 1篇 |
排序方式: 共有282条查询结果,搜索用时 312 毫秒
91.
A dynamic hysteretic constitutive model for soil dynamics, Ramberg-Osgood model, is introduced and improved in the paper. Since the model is inherently 1D and is assumed to apply to shear components only, other components of the deviatorie stress and strain and their relations in 3D case could not be fully described. Two parameters, the equivalent shear stress and the equivalent shear strain, are defined to reasonably establish relations between each of stress and strain components respectively. The constitutive equations of the initial Ramberg-Osgood model are extended to generalize the theory into multidimensional cases. Difficulties of the definition of load reversal in 3D are also addressed and solved. The improved constitutive model for soil dynamics is verified by comparisons with different soil dynamic testing data covering both sands and clays. Results show that the dynamic nonlinear hysteretie behaviors of soils can be well predicted with the improved constitutive model. 相似文献
92.
93.
近两年来,全球新冠肺炎疫情持续蔓延,我们全面贯彻习近平总书记重要指示精神,抓细抓实"外防输入、内防反弹"各项工作,全力落实交通运输部党组关于疫情防控工作部署,做好珠江水运疫情防控常态化工作,阻断疫情水路运输传播渠道,坚决打赢珠江水运疫情防控攻坚战,不断推进珠江水运高质量发展,完成了一份珠江水运生产、防疫双丰收的完美"答... 相似文献
94.
Evaluation industrial factory building damage potential due to ground movements caused by excavations inside the building is a critical design consideration when reconstructing the underground equipment of the industrial factory building. In this paper,the behavior of a support system for a reconstruction project of underground equipment of the industrial factory building in Shanghai and its effects on a pile-foundation supported building are presented. The 8.1 m deep excavation is made through soft clay to... 相似文献
95.
When diaphragm wall is used as the permanent vertical bearing structure,design standard of the bored pile adopted has to induce the risk or iste. The vertical load transfer mechanism and bearing capacity of the diaphragm wall are examined by a field testing program at the site in Shanghai soft clays. Test results indicate that the diaphragm wall almost behaves as a rigid body under the vertical load. It induces that the skin friction and the toe resistance of the wall develop simultaneously. The skin fricti... 相似文献
96.
物联网发展与高职教育之探讨 总被引:4,自引:0,他引:4
文章从物联网的基本概念出发,分析了物联网红火的原因,论述了物联网的发展与高职教育的关系,介绍了高职院校抓住物联网发展机遇应采取的举措。 相似文献
97.
The importance of soil small strain effect on soil-structure behavior was investigated by researchers in last decades. The finite element method (FEM) is always used to predict the excavation behavior, whereas there are not many soil models available to consider this effect in analysis. This paper introduces a simple small strain soil model-hardening small-strain (HSS) in PLAXIS 8.5 and exhibits its application in excavation problems via studying the history of two cases. The analyses also use two familiar soil models: hardening-soil (HS) model and Mohr-Coulomb (MC) model. Results show that the HSS predicts more reasonable magnitudes and profiles of wall deflections and surface settlements than other models. It also indicates that the small strain effect relies on the strain level which is induced by excavation. 相似文献
98.
并联基础隔震体系多目标优化研究 总被引:1,自引:0,他引:1
隔震性能评价是并联基础隔震研究的重要内容,在多目标优化的理论框架下,进行了并联基础隔震体系地震反应优化研究。隔震反应目标包括上部结构最大层间剪力和隔震层最大位移,隔震层决策变量为屈服系数、名义周期和阻尼比。优化的约束条件为上部结构层间剪力不均匀系数在0.85—1.00之间。针对一特定结构,通过NSGA—Ⅱ算法分别进行有约束和无约束条件下的多目标优化研究。研究给出了并联基础隔震多目标优化Pareto最优前沿的一般特征及相关量之间的关系。 相似文献
99.
100.
广州港在“七五”、“八五”期问曾是我国沿海重点发展的三大集装箱港口之一。但是近10年来发展缓慢,1996年全港仪完成国际集装箱55.8万TEU,占珠江三角洲水运集装箱总量的1/3,名列全国港口第4。上海港完成197万TEU,天津港完成82万TEU,青岛港完成81万TEU。与之相比广州港差距甚大。 相似文献