全文获取类型
收费全文 | 22919篇 |
免费 | 908篇 |
国内免费 | 1278篇 |
专业分类
化学 | 9479篇 |
晶体学 | 200篇 |
力学 | 398篇 |
综合类 | 63篇 |
数学 | 11253篇 |
物理学 | 3712篇 |
出版年
2024年 | 35篇 |
2023年 | 365篇 |
2022年 | 266篇 |
2021年 | 288篇 |
2020年 | 441篇 |
2019年 | 554篇 |
2018年 | 484篇 |
2017年 | 392篇 |
2016年 | 468篇 |
2015年 | 552篇 |
2014年 | 782篇 |
2013年 | 1369篇 |
2012年 | 910篇 |
2011年 | 1622篇 |
2010年 | 1250篇 |
2009年 | 1615篇 |
2008年 | 1787篇 |
2007年 | 1575篇 |
2006年 | 1224篇 |
2005年 | 935篇 |
2004年 | 858篇 |
2003年 | 782篇 |
2002年 | 1065篇 |
2001年 | 539篇 |
2000年 | 500篇 |
1999年 | 539篇 |
1998年 | 408篇 |
1997年 | 332篇 |
1996年 | 399篇 |
1995年 | 372篇 |
1994年 | 328篇 |
1993年 | 256篇 |
1992年 | 229篇 |
1991年 | 180篇 |
1990年 | 151篇 |
1989年 | 166篇 |
1988年 | 110篇 |
1987年 | 114篇 |
1986年 | 99篇 |
1985年 | 130篇 |
1984年 | 106篇 |
1983年 | 63篇 |
1982年 | 98篇 |
1981年 | 96篇 |
1980年 | 49篇 |
1979年 | 36篇 |
1978年 | 32篇 |
1977年 | 43篇 |
1976年 | 32篇 |
1971年 | 22篇 |
排序方式: 共有10000条查询结果,搜索用时 78 毫秒
121.
Branislav Jurčo 《Letters in Mathematical Physics》1991,21(1):51-58
The coherent states for the simplest quantum groups (q-Heisenberg-Weyl, SU
q
(2) and the discrete series of representations of SU
q
(1, 1)) are introduced and their properties investigated. The corresponding analytic representations, path integrals, and q-deformation of Berezin's quantization on , a sphere, and the Lobatchevsky plane are discussed. 相似文献
122.
123.
Guo-Feng Zhang 《计算数学(英文版)》2003,21(3):375-382
Consider the following neutral delay-differential equations with multiple delays (NMDDE)$$y'(t)=Ly(t)+\sum_{j=1}^{m}[M_jy(t-\tau_j)+N_jy'(t-\tau_j)],\ \ t\geq 0, (0.1)$$ where $\tau>0$, $L, M_j$ and $N_j$ are constant complex- value $d×d$ matrices. A sufficient condition for the asymptotic stability of NMDDE system (0.1) is given. The stability of Butcher's (A,B,C)-method for systems of NMDDE is studied. In addition, we present a parallel diagonally-implicit iteration RK (PDIRK) methods (NPDIRK) for systems of NMDDE, which is easier to be implemented than fully implicit RK methos. We also investigate the stability of a special class of NPDIRK methods by analyzing their stability behaviors of the solutions of (0.1). 相似文献
124.
125.
The color of a complex number is defined as the number of vertices of the convex hull of powers of that number. This induces a coloring of the unit disk. The structure of the set of points where the color changes is investigated here. It is observed that there is a connection between this fractal set and some family of trinomial equations. Three algorithms for coloring the unit disk are described, the last one (related to the Farey sequence) arising out of a conjecture. This conjecture is formulated and proved in this presentation. 相似文献
126.
In the classical topological context, Dellacherie [10] has given a non-linear version of Hunt's theorem characterizing the proper kernels verifying the complete maximum principle as those closing a submarkovian resolvent. In this paper we study the relation between this non-linear version of Hunt's theorem and T-accretivity. 相似文献
127.
Jeff Kahn 《Combinatorica》1992,12(4):417-423
Letn(k) be the least size of an intersecting family ofk-sets with cover numberk, and let
k
denote any projective plane of orderk–1.Theorem There is a constant A such that ifH is a random set ofm Aklogk lines from
k
then Pr(H<)0(k).Corollary
If there exists a
k
thenn(k)=O(klogk). These statements were conjectured by P. Erds and L. Lovász in 1973.Supported in part by NSF-DMS87-83558 and AFOSR grants 89-0066, 89-0512 and 90-0008 相似文献
128.
A second order nonlinear differential equation
相似文献
129.
130.
Alexander V. Rozenblyum 《Acta Appl Math》1992,29(3):171-240
This work is devoted to the construction and investigation of two new classes of special functions, related to representations of groups of motions in the spaces of constant curvature as well as the unitary group of large ranks. These are special functions with matrix indices and some types of orthogonal polynomials in several continuous and discrete variables. The functions introduced generalize a number of classical scalar special functions in one variable. 相似文献
|