全文获取类型
收费全文 | 11542篇 |
免费 | 248篇 |
国内免费 | 275篇 |
专业分类
化学 | 1432篇 |
晶体学 | 31篇 |
力学 | 77篇 |
综合类 | 17篇 |
数学 | 9713篇 |
物理学 | 795篇 |
出版年
2023年 | 19篇 |
2022年 | 47篇 |
2021年 | 26篇 |
2020年 | 42篇 |
2019年 | 247篇 |
2018年 | 281篇 |
2017年 | 151篇 |
2016年 | 101篇 |
2015年 | 122篇 |
2014年 | 290篇 |
2013年 | 713篇 |
2012年 | 350篇 |
2011年 | 671篇 |
2010年 | 605篇 |
2009年 | 901篇 |
2008年 | 870篇 |
2007年 | 872篇 |
2006年 | 662篇 |
2005年 | 428篇 |
2004年 | 382篇 |
2003年 | 299篇 |
2002年 | 235篇 |
2001年 | 218篇 |
2000年 | 232篇 |
1999年 | 255篇 |
1998年 | 255篇 |
1997年 | 178篇 |
1996年 | 244篇 |
1995年 | 251篇 |
1994年 | 251篇 |
1993年 | 193篇 |
1992年 | 171篇 |
1991年 | 125篇 |
1990年 | 142篇 |
1989年 | 142篇 |
1988年 | 91篇 |
1987年 | 95篇 |
1986年 | 105篇 |
1985年 | 139篇 |
1984年 | 110篇 |
1983年 | 57篇 |
1982年 | 94篇 |
1981年 | 67篇 |
1980年 | 78篇 |
1979年 | 58篇 |
1978年 | 60篇 |
1977年 | 39篇 |
1976年 | 33篇 |
1975年 | 24篇 |
1973年 | 17篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
51.
C. Praagman 《Aequationes Mathematicae》1987,33(1):251-259
In this paper it is proved that having a logarithm is equivalent to having roots of arbitrary order in the group of automorphisms of a formal power series ring, and in algebraic subgroups too 相似文献
52.
Summary The optimality question for blockp-cyclic SOR iterations discussed in Young and Varga is answered under natural conditions on the spectrum of the block Jacobi matrix. In particular, it is shown that repartitioning a blockp-cyclic matrix into a blockq-cyclic form,q
, results in asymptotically faster SOR convergence for the same amount of work per iteration. As a consequence block 2-cyclic SOR is optimal under these conditions.Research supported in part by the US Air Force under Grant no. AFOSR-88-0285 and the National Science Foundation under grant no. DMS-85-21154 Present address: Boeing Computer Services, P.O. Box 24346, MS 7L-21, Seattle, WA 98124-0346, USA 相似文献
53.
Piotr Niemiec 《Topology and its Applications》2006,153(18):3373-3382
Equicontinuous semigroups of transformations of a compact Hausdorff space and their sets of all invariant (Borel, regular and probabilistic) measures are studied. Conditions equivalent to the existence of at least one invariant measure are given. The (algebraic and topological) structure of the set of invariant measures is researched. 相似文献
54.
Diem Ho 《Numerische Mathematik》1989,56(7):721-734
Summary The acceleration by Tchebychev iteration for solving nonsymmetric eigenvalue problems is dicussed. A simple algorithm is derived to obtain the optimal ellipse which passes through two eigenvalues in a complex plane relative to a reference complex eigenvalue. New criteria are established to identify the optimal ellipse of the eigenspectrum. The algorithm is fast, reliable and does not require a search for all possible ellipses which enclose the spectrum. The procedure is applicable to nonsymmetric linear systems as well. 相似文献
55.
In this paper, we establish some new nonlinear integral inequalities of the Gronwall–Bellman–Ou-Iang-type in two variables. These on the one hand generalizes and on the other hand furnish a handy tool for the study of qualitative as well as quantitative properties of solutions of differential equations. We illustrate this by applying our new results to certain boundary value problem. 相似文献
56.
Weak vector equilibrium problems with bi-variable mappings from product space of two bounded complete locally convex Hausdorff topological vector spaces to another topological vector space are studied. The existence theorems of solutions are proved by the FKKM fixed point theorem. Viscosity principle of vector equilibrium problems is dealt with. The relations between solutions of the vector equilibrium problem and those of its perturbation problem are presented. 相似文献
57.
Common fixed-point results are established for a new class of noncommuting selfmaps. We apply them to obtain several invariant approximation results which unify, extend, and complement well-known results. 相似文献
58.
Mathias Lederer 《Annals of Combinatorics》2006,10(3):389-394
From Kostant’s multiplicity formula for general linear groups, one can derive a formula for the Kostka numbers. In this note
we give a combinatorial proof of this formula.
Received January 7, 2005 相似文献
59.
Vsevolod K. Malinovskii 《Acta Appl Math》1994,34(1-2):261-281
Edgeworth expansions for the distribution of a sequential least squares estimator in the random coefficient autoregressive (RCA) model are derived. The regenerative approach to second-order asymptotic analysis of Markov-type statistical models is developed. 相似文献
60.
Raiko P. Zaikov 《Letters in Mathematical Physics》1994,32(4):283-297
Higher spin extensions of the non-Abelian gauge symmetries for the classical WZNW model are considered. Both linear and nonlinear realizations of the extended affine Kac-Moody algebra are obtained. It is a characteristic property of the WZNW model that it admits a higher spin linear realization of the extended affine Kac-Moody algebra which is equivalent to the corresponding higher spin nonlinear realization of the same algebra. However, in both cases, the higher spin Noether currents do not span an invariant space with respect to their generating transformations. Here, the current space is extended to an invariant space which allows us to gauge the symmetry.Supported by Bulgarian Foundation on Fundamental Research under contract Ph-318/93-95. 相似文献