全文获取类型
收费全文 | 20567篇 |
免费 | 976篇 |
国内免费 | 1091篇 |
专业分类
化学 | 8241篇 |
晶体学 | 155篇 |
力学 | 213篇 |
综合类 | 38篇 |
数学 | 12326篇 |
物理学 | 1661篇 |
出版年
2023年 | 126篇 |
2022年 | 150篇 |
2021年 | 164篇 |
2020年 | 276篇 |
2019年 | 570篇 |
2018年 | 511篇 |
2017年 | 410篇 |
2016年 | 395篇 |
2015年 | 497篇 |
2014年 | 718篇 |
2013年 | 1516篇 |
2012年 | 877篇 |
2011年 | 1198篇 |
2010年 | 1030篇 |
2009年 | 1282篇 |
2008年 | 1494篇 |
2007年 | 1448篇 |
2006年 | 1124篇 |
2005年 | 897篇 |
2004年 | 829篇 |
2003年 | 723篇 |
2002年 | 836篇 |
2001年 | 509篇 |
2000年 | 504篇 |
1999年 | 489篇 |
1998年 | 457篇 |
1997年 | 353篇 |
1996年 | 392篇 |
1995年 | 344篇 |
1994年 | 336篇 |
1993年 | 266篇 |
1992年 | 212篇 |
1991年 | 148篇 |
1990年 | 155篇 |
1989年 | 158篇 |
1988年 | 110篇 |
1987年 | 98篇 |
1986年 | 108篇 |
1985年 | 133篇 |
1984年 | 104篇 |
1983年 | 78篇 |
1982年 | 91篇 |
1981年 | 89篇 |
1980年 | 91篇 |
1979年 | 69篇 |
1978年 | 62篇 |
1977年 | 52篇 |
1976年 | 47篇 |
1974年 | 21篇 |
1973年 | 19篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
Francis Jordan 《Topology and its Applications》2006,153(14):2386-2412
An abstract scheme using particular types of relations on filters leads to general unifying results on stability under supremum and product of local topological properties. We present applications for Fréchetness, strong Fréchetness, countable tightness and countable fan-tightness, some of which recover or refine classical results, some of which are new. The reader may find other applications as well. 相似文献
3.
A Volterra type integral equation in a Hilbert space with an additional linear operator L and a spectral parameter depending
on time is considered. If the parameter does not belong to the spectrum of L unconditional solvability of the considered problem
is proved. In the case where the initial value of the parameter coincides with some isolated point of the spectrum of the
operator L sufficient conditions for solvability are established. The obtained results are applied to the partial integral
equations associated with a contact problem of the theory of elasticity. 相似文献
4.
Saida Sultanic 《Integral Equations and Operator Theory》2006,55(4):573-595
The central question of this paper is the one of finding the right analogue of the Commutant Lifting Theorem for the Bergman
space La2. We also analyze the analogous problem for weighted Bergman spaces La,α2, − 1 < α < ∞. 相似文献
5.
Using Brown's construction (J. Algebra 15 (1970) 103) of an exact 6-term sequence for a fibration of groupoids we show how an exact 9-term sequence can be associated to a fibration of bigroupoids. Applications to topology and algebra are given. 相似文献
6.
Kunyu Guo 《Journal of Functional Analysis》2004,213(2):380-411
This paper mainly concerns defect operators and defect functions of Hardy submodules, Bergman submodules over the unit ball, and Hardy submodules over the polydisk. The defect operator (function) carries key information about operator theory (function theory) and structure of analytic submodules. The problem when a submodule has finite defect is attacked for both Hardy submodules and Bergman submodules. Our interest will be in submodules generated by polynomials. The reason for choosing such submodules is to understand the interaction of operator theory, function theory and algebraic geometry. 相似文献
7.
We show that there are close relations between extremal problems in dual Brunn-Minkowski theory and isotropic-type properties for some Borel measures on the sphere. The methods we use allow us to obtain similar results in the context of Firey-Brunn-Minkowski theory. We also study reverse inequalities for dual mixed volumes which are related with classical positions, such as ?-position or isotropic position. 相似文献
8.
Andrei K. Lerner 《Archiv der Mathematik》2005,85(6):538-543
We show that the Hardy-Littlewood maximal operator and a class of Calderón-Zygmund singular integrals satisfy the strong type
modular inequality in variable Lp spaces if and only if the variable exponent p(x) ∼ const.
Received: 15 September 2004 相似文献
9.
A graph G is N2‐locally connected if for every vertex ν in G, the edges not incident with ν but having at least one end adjacent to ν in G induce a connected graph. In 1990, Ryjá?ek conjectured that every 3‐connected N2‐locally connected claw‐free graph is Hamiltonian. This conjecture is proved in this note. © 2004 Wiley Periodicals, Inc. J Graph Theory 48: 142–146, 2005 相似文献
10.
In this paper we show that for a given 3-manifold and a given Heegaard splitting there are finitely many preferred decomposing systems of 3g−3 disjoint essential disks. These are characterized by a combinatorial criterion which is a slight strengthening of Casson-Gordon's rectangle condition. This is in contrast to fact that in general there can exist infinitely many such systems of disks which satisfy just the Casson-Gordon rectangle condition. 相似文献