全文获取类型
收费全文 | 2775篇 |
免费 | 255篇 |
国内免费 | 259篇 |
专业分类
化学 | 597篇 |
晶体学 | 7篇 |
力学 | 465篇 |
综合类 | 52篇 |
数学 | 972篇 |
物理学 | 1196篇 |
出版年
2023年 | 21篇 |
2022年 | 27篇 |
2021年 | 39篇 |
2020年 | 66篇 |
2019年 | 39篇 |
2018年 | 46篇 |
2017年 | 66篇 |
2016年 | 85篇 |
2015年 | 74篇 |
2014年 | 171篇 |
2013年 | 229篇 |
2012年 | 128篇 |
2011年 | 178篇 |
2010年 | 132篇 |
2009年 | 179篇 |
2008年 | 190篇 |
2007年 | 201篇 |
2006年 | 175篇 |
2005年 | 145篇 |
2004年 | 140篇 |
2003年 | 112篇 |
2002年 | 108篇 |
2001年 | 94篇 |
2000年 | 77篇 |
1999年 | 80篇 |
1998年 | 60篇 |
1997年 | 64篇 |
1996年 | 48篇 |
1995年 | 42篇 |
1994年 | 40篇 |
1993年 | 32篇 |
1992年 | 33篇 |
1991年 | 21篇 |
1990年 | 15篇 |
1989年 | 14篇 |
1988年 | 19篇 |
1987年 | 7篇 |
1986年 | 14篇 |
1985年 | 13篇 |
1984年 | 10篇 |
1983年 | 6篇 |
1982年 | 8篇 |
1981年 | 7篇 |
1980年 | 8篇 |
1979年 | 5篇 |
1978年 | 4篇 |
1976年 | 5篇 |
1973年 | 3篇 |
1972年 | 2篇 |
1959年 | 2篇 |
排序方式: 共有3289条查询结果,搜索用时 31 毫秒
2.
3.
4.
5.
6.
This paper presents an enhanced version of the elasto-plastic model for partially saturated soil first proposed by Bolzon,
Schrefler and Zienkiewicz in 1996, “BSZ” model, which uses the effective stress tensor and suction as independent stress variables.
It is recalled that the effective stress tensor proposed by Lewis and Schrefler in 1982 is thermodynamically consistent and,
compared with other choices of stress tensors, results particularly suitable for partially saturated soil mechanics. A hydraulic
constitutive relationship and a hydraulic hysteresis are introduced in the model, to take into account the irreversible deformation
during cyclic drying and wetting until structural collapse. For this reason the plastic rate of strain is split into the sum
of two components: one depending on the effective stress tensor and the other one on suction. This is the new feature of the
BSZ model. This enhanced model is then cast into a thermodynamical framework at macroscopic level and it is shown that it
is possible to derive the constitutive law from the Helmholtz free energy and a dissipation function, both for associative
and non- associative plasticity. Finally the model predictions have been compared with experimental data for Sion slime, with
particular emphasis on the deviatoric part, and model predictions of hysteretic behaviour have been investigated in case of
a wetting and drying cycle on compacted betonite–kaolin. 相似文献
7.
8.
9.
We investigate the effects of adding uniformity requirements to concepts in computable structure theory such as computable categoricity (of a structure) and intrinsic computability (of a relation on a computable structure). We consider and compare two different notions of uniformity, previously studied by Kudinov and by Ventsov. We discuss some of their results and establish new ones, while also exploring the connections with the relative computable structure theory of Ash, Knight, Manasse, and Slaman and Chisholm and with previous work of Ash, Knight, and Slaman on uniformity in a general computable structure-theoretical setting. 相似文献
10.