全文获取类型
收费全文 | 44039篇 |
免费 | 1255篇 |
国内免费 | 752篇 |
专业分类
化学 | 7962篇 |
晶体学 | 318篇 |
力学 | 907篇 |
综合类 | 75篇 |
数学 | 27088篇 |
物理学 | 9696篇 |
出版年
2023年 | 148篇 |
2022年 | 254篇 |
2021年 | 174篇 |
2020年 | 254篇 |
2019年 | 1033篇 |
2018年 | 946篇 |
2017年 | 596篇 |
2016年 | 408篇 |
2015年 | 417篇 |
2014年 | 856篇 |
2013年 | 2090篇 |
2012年 | 1130篇 |
2011年 | 2154篇 |
2010年 | 1730篇 |
2009年 | 2466篇 |
2008年 | 2671篇 |
2007年 | 2680篇 |
2006年 | 2229篇 |
2005年 | 1494篇 |
2004年 | 1753篇 |
2003年 | 1749篇 |
2002年 | 2021篇 |
2001年 | 1996篇 |
2000年 | 1861篇 |
1999年 | 2054篇 |
1998年 | 1781篇 |
1997年 | 1172篇 |
1996年 | 892篇 |
1995年 | 748篇 |
1994年 | 694篇 |
1993年 | 482篇 |
1992年 | 407篇 |
1991年 | 273篇 |
1990年 | 334篇 |
1989年 | 333篇 |
1988年 | 235篇 |
1987年 | 223篇 |
1986年 | 252篇 |
1985年 | 394篇 |
1984年 | 327篇 |
1983年 | 174篇 |
1982年 | 305篇 |
1981年 | 388篇 |
1980年 | 332篇 |
1979年 | 180篇 |
1978年 | 260篇 |
1977年 | 191篇 |
1976年 | 160篇 |
1975年 | 113篇 |
1974年 | 100篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
211.
The large deviation theorems, exponential inequalities and a non-uniform estimate of the Berry–Esséen theorem in a discounted version are proved.Dedicated to Professor Vytautas Statulevičius on the occasion of his 75th birthday. 相似文献
212.
Piotr Ko?cielniak 《Topology and its Applications》2007,154(9):1951-1955
Let M be a compact manifold with dimM?2. We prove that some iteration of the generic homeomorphism on M is semiconjugated to the shift map and has infinite topological entropy (Theorem 1.1). 相似文献
213.
On the third largest Laplacian eigenvalue of a graph 总被引:1,自引:0,他引:1
Ji-Ming Guo 《Linear and Multilinear Algebra》2007,55(1):93-102
In this article, a sharp lower bound for the third largest Laplacian eigenvalue of a graph is given in terms of the third largest degree of the graph. 相似文献
214.
Teruhisa Tsuda 《Letters in Mathematical Physics》2006,77(1):21-30
Starting from certain point sets in the projective plane, we construct a tropical (or subtraction-free birational) representation of Weyl groups over the field of τ-functions. In particular, our construction includes E
8
(1)
, E
7
(1)
, E
6
(1)
and D
5
(1)
as affine cases; each of them gives rise to the q-difference Painlevé equation. 相似文献
215.
Michael Holcomb 《Topology and its Applications》2007,154(1):124-143
One can form a polygonal linkage by identifying initial and terminal points of two free linkages. Likewise, one can form a multipolygonal linkage by identifying initial and terminal points of three free linkages. The geometric and topological properties of moduli spaces of multipolygonal linkages in the plane are studied. These spaces are compact algebraic varieties. Some conditions under which these spaces are smooth manifolds, cross products or disjoint unions of moduli spaces of polygonal linkages, or connected, are determined. Dimensions in smooth manifold cases and some Euler characteristics are computed. A classification of generic multiquadrilateral linkages is also made. 相似文献
216.
The q-Catalan numbers studied by Carlitz and Riordan are polynomials in q with nonnegative coefficients. They evaluate, at q = 1, to the Catalan numbers: 1, 1, 2, 5, 14,…, a log-convex sequence. We use a combinatorial interpretation of these polynomials
to prove a q-log-convexity result. The sequence of q-Catalan numbers is not q-log-convex in the narrow sense used by other authors, so our work suggests a more flexible definition of q-log convex be adopted.
Received January 2, 2007 相似文献
217.
We present a framework for extending Stone's representation theorem for distributive lattices to representation theorems for distributive lattices with operators. We proceed by introducing the definition of algebraic theory of operators over distributive lattices. Each such theory induces a functor on the category of distributive lattices such that its algebras are exactly the distributive lattices with operators in the original theory. We characterize the topological counterpart of these algebras in terms of suitable coalgebras on spectral spaces. We work out some of these coalgebraic representations, including a new representation theorem for distributive lattices with monotone operators. 相似文献
218.
We study the inverse scattering problem for the nonlinear Schrödinger equation and for the nonlinear Klein–Gordon equation with the generalized Hartree type nonlinearity. We reconstruct the nonlinearity from knowledge of the scattering operator, which improves the known results. 相似文献
219.
220.
The notion of balanced bipartitions of the vertices in a tree T was introduced and studied by Reid (Networks 34 (1999) 264). Reid proved that the set of balance vertices of a tree T consists of a single vertex or two adjacent vertices. In this note, we give a simple proof of that result. 相似文献