全文获取类型
收费全文 | 409017篇 |
免费 | 4084篇 |
国内免费 | 1305篇 |
专业分类
化学 | 223008篇 |
晶体学 | 6568篇 |
力学 | 16646篇 |
综合类 | 13篇 |
数学 | 44108篇 |
物理学 | 124063篇 |
出版年
2020年 | 3213篇 |
2019年 | 3637篇 |
2018年 | 4362篇 |
2017年 | 4337篇 |
2016年 | 6731篇 |
2015年 | 4448篇 |
2014年 | 6791篇 |
2013年 | 18664篇 |
2012年 | 13371篇 |
2011年 | 16535篇 |
2010年 | 11231篇 |
2009年 | 11155篇 |
2008年 | 14796篇 |
2007年 | 14822篇 |
2006年 | 13794篇 |
2005年 | 12700篇 |
2004年 | 11458篇 |
2003年 | 10412篇 |
2002年 | 10063篇 |
2001年 | 12012篇 |
2000年 | 9047篇 |
1999年 | 7086篇 |
1998年 | 5795篇 |
1997年 | 5759篇 |
1996年 | 5366篇 |
1995年 | 5127篇 |
1994年 | 4817篇 |
1993年 | 4759篇 |
1992年 | 5594篇 |
1991年 | 5540篇 |
1990年 | 5315篇 |
1989年 | 5284篇 |
1988年 | 5331篇 |
1987年 | 5321篇 |
1986年 | 5061篇 |
1985年 | 6709篇 |
1984年 | 6838篇 |
1983年 | 5500篇 |
1982年 | 5958篇 |
1981年 | 5880篇 |
1980年 | 5558篇 |
1979年 | 5912篇 |
1978年 | 6070篇 |
1977年 | 6117篇 |
1976年 | 6101篇 |
1975年 | 5473篇 |
1974年 | 5555篇 |
1973年 | 5827篇 |
1972年 | 3773篇 |
1968年 | 3078篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
111.
A new parallel storm surge model, the Parallel Environmental Model (PEM), is developed and tested by comparisons with analytic solutions. The PEM is a 2‐D vertically averaged, wetting and drying numerical model and can be operated in explicit, semi‐implicit and fully implicit modes. In the implicit mode, the propagation, Coriolis and bottom friction terms can all be treated implicitly. The advection and diffusion terms are solved with a parallel Eulerian–Lagrangian scheme developed for this study. The model is developed specifically for use on parallel computer systems and will function accordingly in either explicit of implicit modes. Storm boundary conditions are based on a simple exponential decay of pressure from the centre of a storm. The simulated flooding caused by a major Category 5 hurricane making landfall in the Indian River Lagoon, Florida is then presented as an example application of the PEM. Copyright © 2003 John Wiley & Sons, Ltd. 相似文献
112.
113.
114.
115.
Russian Journal of General Chemistry - 相似文献
116.
R.J Hand 《Journal of Non》2003,315(3):276-287
Glass may be strengthened by epoxy coatings although the strengthening mechanisms remain unclear. Possible strengthening mechanisms are reviewed and are used to analyse strength data for both a solvent based and a water based coating system. The coatings either fill (solvent based coatings), or partially fill (water based coatings) surface cracks and it is shown that closure stresses arising from the thermal expansion mismatch of the coating within these cracks can account for the observed degrees of strengthening. It is also demonstrated that other suggested mechanisms such as flaw healing cannot fully account for the observed degree of strengthening. 相似文献
117.
In the present paper, the notion of norm series with respect to the norm residue symbol is generalized to high-dimensional local fields. Necessary and sufficient conditions for the existence of norm series are obtained. Bibliography: 12 titles.__________Translated from Zapiski Nauchnykh Seminarov POMI, Vol. 305, 2003, pp. 60–83. 相似文献
118.
119.
120.
We prove new theorems on the justification of the averaging method for multifrequency oscillation systems with pulse influence at fixed times. 相似文献