全文获取类型
收费全文 | 10672篇 |
免费 | 374篇 |
国内免费 | 52篇 |
专业分类
化学 | 5402篇 |
晶体学 | 220篇 |
力学 | 217篇 |
综合类 | 41篇 |
数学 | 1463篇 |
物理学 | 3755篇 |
出版年
2023年 | 55篇 |
2022年 | 135篇 |
2021年 | 152篇 |
2020年 | 111篇 |
2019年 | 167篇 |
2018年 | 211篇 |
2017年 | 177篇 |
2016年 | 305篇 |
2015年 | 246篇 |
2014年 | 319篇 |
2013年 | 741篇 |
2012年 | 444篇 |
2011年 | 698篇 |
2010年 | 550篇 |
2009年 | 480篇 |
2008年 | 463篇 |
2007年 | 501篇 |
2006年 | 466篇 |
2005年 | 400篇 |
2004年 | 406篇 |
2003年 | 498篇 |
2002年 | 390篇 |
2001年 | 352篇 |
2000年 | 236篇 |
1999年 | 163篇 |
1998年 | 152篇 |
1997年 | 106篇 |
1996年 | 94篇 |
1995年 | 134篇 |
1994年 | 74篇 |
1993年 | 72篇 |
1992年 | 91篇 |
1991年 | 61篇 |
1990年 | 86篇 |
1989年 | 78篇 |
1988年 | 77篇 |
1987年 | 76篇 |
1986年 | 78篇 |
1985年 | 113篇 |
1984年 | 127篇 |
1983年 | 76篇 |
1982年 | 84篇 |
1981年 | 88篇 |
1980年 | 101篇 |
1979年 | 68篇 |
1978年 | 73篇 |
1977年 | 78篇 |
1976年 | 68篇 |
1975年 | 64篇 |
1974年 | 51篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
12.
13.
14.
Teresa Regińska 《BIT Numerical Mathematics》2004,44(1):119-133
The paper concerns conditioning aspects of finite-dimensional problems arising when the Tikhonov regularization is applied
to discrete ill-posed problems. A relation between the regularization parameter and the sensitivity of the regularized solution
is investigated. The main conclusion is that the condition number can be decreased only to the square root of that for the
nonregularized problem. The convergence of solutions of regularized discrete problems to the exact generalized solution is
analyzed just in the case when the regularization corresponds to the minimal condition number. The convergence theorem is
proved under the assumption of the suitable relation between the discretization level and the data error. As an example the
method of truncated singular value decomposition with regularization is considered.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
15.
The variational approach based on the covariant quantization method for the curved Einstein space is applied. 相似文献
16.
Hubert Grudziński 《Reports on Mathematical Physics》2004,53(2):317-328
The eigenvalues and eigenfunctions of an elementary 3-fermion 2-body operator 3P2g∧I1A3∑1≤i≤j≤3P2g(i, j)A3 acting on a 3-particle antisymmetric finite-dimensional Hilbert space have been found. Here Pg2 denotes the projection operator onto a 2-particle antisymmetric function g2, while A3 denotes the 3-particle antisymmetrizing operator. 相似文献
17.
We introduce here some Itô calculus for non-continuous Dirichlet processes. Such calculus extends what was known for continuous Dirichlet processes or for semimartingales. In particular we prove that non-continuous Dirichlet processes are stable under C
1 transformation. 相似文献
18.
JPC – Journal of Planar Chromatography – Modern TLC - This paper reports the efficiency of the C30 phase for HPLC and TLC separation of a mixture of tocopherol homologs and... 相似文献
19.
JPC – Journal of Planar Chromatography – Modern TLC - Flavonoid glycosides are much more polar than their aglycones and the two groups of compounds are difficult to separate by planar... 相似文献
20.
Jan Cieliski 《Chaos, solitons, and fractals》1995,5(12):2303-2313
An effective algorithm to construct the Darboux matrix based on the dressing method is proposed. Our approach consists in representing the linear problem as a system of algebraic constraints on two matrices. The Darboux matrix is determined from the requirement that the Darboux-Bäcklund transformation preserves these constraints. A non-isospectral deformation of the derivative nonlinear Schrödinger equation is discussed as an example. 相似文献