全文获取类型
收费全文 | 4607篇 |
免费 | 406篇 |
国内免费 | 506篇 |
专业分类
化学 | 324篇 |
晶体学 | 14篇 |
力学 | 132篇 |
综合类 | 103篇 |
数学 | 4073篇 |
物理学 | 873篇 |
出版年
2024年 | 10篇 |
2023年 | 59篇 |
2022年 | 48篇 |
2021年 | 80篇 |
2020年 | 128篇 |
2019年 | 132篇 |
2018年 | 177篇 |
2017年 | 184篇 |
2016年 | 135篇 |
2015年 | 108篇 |
2014年 | 156篇 |
2013年 | 669篇 |
2012年 | 161篇 |
2011年 | 194篇 |
2010年 | 180篇 |
2009年 | 215篇 |
2008年 | 287篇 |
2007年 | 276篇 |
2006年 | 233篇 |
2005年 | 239篇 |
2004年 | 213篇 |
2003年 | 204篇 |
2002年 | 208篇 |
2001年 | 193篇 |
2000年 | 178篇 |
1999年 | 154篇 |
1998年 | 140篇 |
1997年 | 105篇 |
1996年 | 85篇 |
1995年 | 48篇 |
1994年 | 41篇 |
1993年 | 24篇 |
1992年 | 26篇 |
1991年 | 28篇 |
1990年 | 21篇 |
1989年 | 11篇 |
1988年 | 22篇 |
1987年 | 18篇 |
1986年 | 12篇 |
1985年 | 18篇 |
1984年 | 12篇 |
1983年 | 12篇 |
1982年 | 10篇 |
1981年 | 5篇 |
1980年 | 10篇 |
1979年 | 10篇 |
1978年 | 11篇 |
1977年 | 6篇 |
1976年 | 9篇 |
1974年 | 4篇 |
排序方式: 共有5519条查询结果,搜索用时 546 毫秒
71.
We investigate the propeties of differential algebras generated by an operator d satisfying the property dN = 0 instead of d2 = 0 as in the usual case. Several examples of realizations of such differential algebras are given, either in the context of ZN-graded N × N matrix algebras, or as a generalized differential calculus on manifolds. 相似文献
72.
Solubility of carbon dioxide in aqueous solutions of sodium chloride: Experimental results and correlation 总被引:2,自引:0,他引:2
The solubility of carbon dioxide in aqueous solutions of sodium chloride was measured in the temperature range from 40 to 160°C, up to 6 mol-kg salt solutions and total pressures up to 10 MPa. Pitzer's(1) equations as well as the Chen and Evans(2) model were used to correlate the new data. Results are reported and compared to literature data and correlations. 相似文献
73.
Matthew Fayers 《Algebras and Representation Theory》2005,8(3):415-426
In Fayers and Martin [J. Algebra 240 (2001), 859–873], the author and Martin constructed embeddings of Schur algebras S(2,r)↪S(2,R). Here, we generalise to the q-Schur algebras Sq(2,r).
Presented by A. Verschoren
Mathematics Subject Classifications (2000) 20G05, 20C33. 相似文献
74.
郑州工程学院数理系 《数学物理学报(A辑)》2004,24(3):329-336
该文考虑一类新的非线性方程(|ut|r-2ut)t-Δutt-Δu-ρ(t)Δut=f(u) 的初边值问题,利用小扰动法证明了整体弱解的
存在性,借用位势井的概念得到了解的稳定性.〖HT5”H〗关键词:〖HT5”SS〗非线性发展方程;初边值问题;整体弱解;稳定性. 相似文献
75.
von-Neumann正则环与左SF-环 总被引:6,自引:0,他引:6
环R称为左SF-环,如果每个单左R-模是平坦的.众所周知,Von-Neumann正则环是SF-环,但SF-环是否是正则环至今仍是公开问题,本文主要研究左SF-环是正则环的条件,证明了:如果R是左SF-环且R的每个极大左(右)理想是广义弱理想,那么R是强正则环.并且推广了Rege[3]中的相应结果. 相似文献
76.
该文通过一种基本的分析方法,得到了一类退化型Schrodinger方程解的连续性结果,方程的类型为:Lu+vu=(f_i)_{x_i},其中L为一退化椭圆算子,v属于某一Kato类的类比,而f_i 属于某一加权L^p空间. 相似文献
77.
Simone Calogero 《Journal of Differential Equations》2004,204(2):323-338
The Nordström-Vlasov system is a Lorentz invariant model for a self-gravitating collisionless gas. We establish suitable a priori bounds on the solutions of this system, which together with energy estimates and the smoothing effect of “momentum averaging” yield the existence of global weak solutions to the corresponding initial value problem. In the process we improve the continuation criterion for classical solutions which was derived recently. The weak solutions are shown to preserve mass. 相似文献
78.
Under suitable assumptions, a functional central limit theorem is obtained for a three-dimensional model of Maxwellian molecules. This model is related to a nonlinear Boltzmann-type equation. It will be proved that the family of the distributions induced by fluctuation processes converges weakly. 相似文献
79.
In the paper we obtain vector-valued inequalities for Calder6n-Zygmund operator, simply CZO on Herz space and weak Herz space. In particular.we obtain vector-valued inequalities for CZO on Lq(Rd, |x|αdμ) space, with 1< q <∞, -n <α< n(q -1), and on L1,∞(Rd,|x|αdμ) space, with -n <α< 0. 相似文献
80.
Nadjib Bouzar 《Annals of the Institute of Statistical Mathematics》2004,56(3):497-510
The purpose of this paper is to introduce and study the concepts of discrete semi-stability and geometric semi-stability for
distributions with support inZ
+. We offer several properties, including characterizations, of discrete semi-stable distributions. We establish that these
distributions posses the property of infinite divisibility and that their probability generating functions admit canonical
representations that are analogous to those of their continuous counterparts. Properties of discrete geometric semi-stable
distributions are deduced from the results obtained for discrete semi-stability. Several limit theorems are established and
some examples are constructed. 相似文献