全文获取类型
收费全文 | 11262篇 |
免费 | 1035篇 |
国内免费 | 752篇 |
专业分类
化学 | 2104篇 |
晶体学 | 27篇 |
力学 | 800篇 |
综合类 | 225篇 |
数学 | 7213篇 |
物理学 | 2680篇 |
出版年
2024年 | 21篇 |
2023年 | 117篇 |
2022年 | 171篇 |
2021年 | 231篇 |
2020年 | 292篇 |
2019年 | 300篇 |
2018年 | 279篇 |
2017年 | 322篇 |
2016年 | 417篇 |
2015年 | 276篇 |
2014年 | 514篇 |
2013年 | 948篇 |
2012年 | 472篇 |
2011年 | 657篇 |
2010年 | 594篇 |
2009年 | 663篇 |
2008年 | 689篇 |
2007年 | 709篇 |
2006年 | 610篇 |
2005年 | 574篇 |
2004年 | 501篇 |
2003年 | 492篇 |
2002年 | 443篇 |
2001年 | 366篇 |
2000年 | 344篇 |
1999年 | 284篇 |
1998年 | 268篇 |
1997年 | 199篇 |
1996年 | 189篇 |
1995年 | 155篇 |
1994年 | 116篇 |
1993年 | 98篇 |
1992年 | 94篇 |
1991年 | 93篇 |
1990年 | 56篇 |
1989年 | 57篇 |
1988年 | 47篇 |
1987年 | 36篇 |
1986年 | 45篇 |
1985年 | 47篇 |
1984年 | 38篇 |
1983年 | 16篇 |
1982年 | 30篇 |
1981年 | 30篇 |
1980年 | 28篇 |
1979年 | 33篇 |
1978年 | 18篇 |
1977年 | 20篇 |
1976年 | 24篇 |
1974年 | 10篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
201.
Chen Jianlong 《数学季刊》1996,(1)
Moore-Penrose Inverses and Group Inverses of Block k-Circulant MatricesMoore-PenroseInversesandGroupInversesofBlockk-Circulan... 相似文献
202.
ACLASSOFFACTORIZATIONUPDATEALGORITHMFORSOLVINGSYSTEMSOFSPARSENONLINEAREQUATIONSBAIZHONGZHI(InstituteofComputationalMathematic... 相似文献
203.
204.
矩阵的多行拟相合分类及其应用 总被引:1,自引:0,他引:1
本文把方阵的拟相合概念推广为长方阵的多行拟相合概念,并对最简情形即M2,4(Fp)给出分类结果.此概念之一应用出现在有限环的同构分类之中. 相似文献
205.
设G为任意群,本文借助于环的矩阵表示给出了G-分次环与任意可迁G-集的smash积是素环或单环的刻画. 相似文献
206.
R. B. Arellano-Valle H. Bolfarine 《Annals of the Institute of Statistical Mathematics》1996,48(1):111-125
In this paper we investigate some aspects like estimation and hypothesis testing in the simple structural regression model with measurement errors. Use is made of orthogonal parametrizations obtained in the literature. Emphasis is placed on some properties of the maximum likelihood estimators and also on the distribution of the likelihood ratio statistics. 相似文献
207.
Xiao-Qing Jin 《BIT Numerical Mathematics》1996,36(1):101-109
We study methods for solving the constrained and weighted least squares problem min
x
by the preconditioned conjugate gradient (PCG) method. HereW = diag (1, ,
m
) with 1
m
0, andA
T
= [T
1
T
, ,T
k
T
] with Toeplitz blocksT
l
R
n × n
,l = 1, ,k. It is well-known that this problem can be solved by solving anaugmented linear 2 × 2 block linear systemM +Ax =b, A
T
= 0, whereM =W
–1. We will use the PCG method with circulant-like preconditioner for solving the system. We show that the spectrum of the preconditioned matrix is clustered around one. When the PCG method is applied to solve the system, we can expect a fast convergence rate.Research supported by HKRGC grants no. CUHK 178/93E and CUHK 316/94E. 相似文献
208.
The generalized linear complementarity problem revisited 总被引:5,自引:0,他引:5
Given a vertical block matrixA, we consider in this paper the generalized linear complementarity problem VLCP(q, A) introduced by Cottle and Dantzig. We formulate this problem as a linear complementarity problem with a square matrixM, a formulation which is different from a similar formulation given earlier by Lemke. Our formulation helps in extending many
well-known results in linear complementarity to the generalized linear complementarity problem. We also show that the class
of vertical block matrices which Cottle and Dantzig's algorithm can process is the same as the class of equivalent square
matrices which Lemke's algorithm can process. We also present some degree-theoretic results on a vertical block matrix. 相似文献
209.
We compute constrained equilibria satisfying an optimality condition. Important examples include convex programming, saddle
problems, noncooperative games, and variational inequalities. Under a monotonicity hypothesis we show that equilibrium solutions
can be found via iterative convex minimization. In the main algorithm each stage of computation requires two proximal steps,
possibly using Bregman functions. One step serves to predict the next point; the other helps to correct the new prediction.
To enhance practical applicability we tolerate numerical errors.
Research supported partly by the Norwegian Research Council, project: Quantec 111039/401. 相似文献
210.
Kh. D. Ikramov 《Mathematical Notes》1996,60(6):649-657
LetR be a (real or complex) triangular matrix of ordern, say, an upper triangular matrix. Is it true that there exists a normaln×n matrixA whose upper triangle coincides with the upper triangle ofR? The answer to this question is “yes” and is obvious in the following cases: (1)R is real; (2)R is a complex matrix with a real or a pure imaginary main diagonal, and moreover, all the diagonal entries ofR belong to a straight line. The answer is also in the affirmative (although it is not so obvious) for any matrixR of order 2. However, even forn=3 this problem remains unsolved. In this paper it is shown that the answer is in the affirmative also for 3×3 matrices. 相似文献