全文获取类型
收费全文 | 13049篇 |
免费 | 867篇 |
国内免费 | 1571篇 |
专业分类
化学 | 4751篇 |
晶体学 | 100篇 |
力学 | 211篇 |
综合类 | 152篇 |
数学 | 8307篇 |
物理学 | 1966篇 |
出版年
2024年 | 13篇 |
2023年 | 115篇 |
2022年 | 178篇 |
2021年 | 275篇 |
2020年 | 286篇 |
2019年 | 364篇 |
2018年 | 346篇 |
2017年 | 362篇 |
2016年 | 273篇 |
2015年 | 264篇 |
2014年 | 426篇 |
2013年 | 1277篇 |
2012年 | 472篇 |
2011年 | 695篇 |
2010年 | 607篇 |
2009年 | 773篇 |
2008年 | 871篇 |
2007年 | 1067篇 |
2006年 | 825篇 |
2005年 | 695篇 |
2004年 | 612篇 |
2003年 | 636篇 |
2002年 | 529篇 |
2001年 | 457篇 |
2000年 | 430篇 |
1999年 | 397篇 |
1998年 | 375篇 |
1997年 | 335篇 |
1996年 | 248篇 |
1995年 | 191篇 |
1994年 | 194篇 |
1993年 | 130篇 |
1992年 | 119篇 |
1991年 | 87篇 |
1990年 | 72篇 |
1989年 | 68篇 |
1988年 | 56篇 |
1987年 | 55篇 |
1986年 | 38篇 |
1985年 | 57篇 |
1984年 | 34篇 |
1983年 | 24篇 |
1982年 | 32篇 |
1981年 | 25篇 |
1980年 | 23篇 |
1979年 | 15篇 |
1978年 | 18篇 |
1977年 | 15篇 |
1976年 | 12篇 |
1974年 | 6篇 |
排序方式: 共有10000条查询结果,搜索用时 437 毫秒
981.
982.
Effects of uncertainties in the domain on the solution of Dirichlet boundary value problems 总被引:1,自引:0,他引:1
Summary. A domain with possibly non-Lipschitz boundary is defined as a limit of monotonically expanding or shrinking domains with
Lipschitz boundary. A uniquely solvable Dirichlet boundary value problem (DBVP) is defined on each of the Lipschitz domains
and the limit of these solutions is investigated. The limit function also solves a DBVP on the limit domain but the problem
can depend on the sequences of domains if the limit domain is unstable with respect to the DBVP. The core of the paper consists
in estimates of the difference between the respective solutions of the DBVP on two close domains, one of which is Lipschitz
and the other can be unstable. Estimates for starshaped as well as rather general domains are derived. Their numerical evaluation
is possible and can be done in different ways.
Received October 16, 2001 / Revised version received January 16, 2002 / Published online: April 17, 2002
RID="*"
ID="*" The research was funded partially by the National Science Foundation under the grants NSF–Czech Rep. INT-9724783 and
NSF DMS-9802367
RID="**"
ID="**" Support for Jan Chleboun coming from the Grant Agency of the Czech Republic through grant 201/98/0528 is appreciated 相似文献
983.
We show the existence of a rank function on finitely generated modules over group algebras , where is an arbitrary field and is a finitely generated amenable group. This extends a result of W. Lück (1998).
984.
Andrea Iannuzzi 《Proceedings of the American Mathematical Society》2003,131(12):3839-3843
Let act by biholomorphisms on a taut manifold . We show that can be regarded as a -invariant domain in a complex manifold on which the universal complexification of acts. If is also Stein, an analogous result holds for actions of a larger class of real Lie groups containing, e.g., abelian and certain nilpotent ones. In this case the question of Steinness of is discussed.
985.
D. A. Malinin 《Algebras and Representation Theory》2003,6(2):215-237
For a given field F of characteristic 0 we consider a normal extension E/F of finite degree d and finite Abelian subgroups GGL
n
(E) of a given exponent t. We assume that G is stable under the natural action of the Galois group of E/F and consider the fields E=F(G) that are obtained via adjoining all matrix coefficients of all matrices gG to F. It is proved that under some reasonable restrictions for n, any E can be realized as F(G), while if all coefficients of matrices in G are algebraic integers, there are only finitely many fields E=F(G) for prescribed integers n and t or prescribed n and d. 相似文献
986.
FuZhengWANG 《数学学报(英文版)》2003,19(1):89-96
Let E/K be an elliptic curve with K-rational p-torsion points.The p-Selmer group of E is described by the image of a map λk and hence an upper bound of its order is given in terms of the class numbers of the S-ideal class group of K and the p-division field of E. 相似文献
987.
BaoShanWANG JiPingZHANG 《数学学报(英文版)》2003,19(1):29-34
In this paper,we shall mainly study the p-solvable finite group in terms of p-local rank,and a group theoretic characterization will be given of finite p-solvabel groups with p-local rank two.Theorem A Let G be a finite p-solvable group with p-local rank plr(G)=2 and Op(G)=1.If P is a Sylow p-subgrounp of G,then P has a normal subgroup Q such that P/Q is cyclic or a generalized quaternion 2-group and the p-rank of Q is at most two.Theorem B Let G be a finite p-solvable group with Op(G)=1.Then the p-length lp(G)≤plr(G);if in addition plr(G)=lp (G) and p≥5 is odd,then plr(G)=0 or 1. 相似文献
988.
On "Problems on von Neumann Algebras by R. Kadison, 1967" 总被引:1,自引:0,他引:1
LiMingGE 《数学学报(英文版)》2003,19(3):619-624
A brief summary of the development on Kadison‘s famous problems (1967) is given. A new set of problems in von Neumann algebras is listed. 相似文献
989.
1. PreliminaryIt is well known that{1] a 8ymPlectic form is invariant along the trajectory of a Hamilto-nian system. Based on this fundamental property, certain techniques have been developed.The purpose of this paper is to extend such an approach to a wider class of dynamic systeIns,namely, genera1ized Hamiltonian systems. Our purpose is to investigate a class of dynaInicsystems, which possess a certain "geometric structure".Deflnition 1.1[1'2]. Let M be a tIlallifo1d. w E fl'(M) is call… 相似文献
990.
In this paper we introduce a class of operators naturally extending the classes of hyponormal and posinormal operators. For this class we construct a generating family of eigendistributions, unitary invariants and a functional model. 相似文献