全文获取类型
收费全文 | 8079篇 |
免费 | 696篇 |
国内免费 | 1100篇 |
专业分类
化学 | 86篇 |
力学 | 221篇 |
综合类 | 194篇 |
数学 | 8184篇 |
物理学 | 1190篇 |
出版年
2024年 | 12篇 |
2023年 | 78篇 |
2022年 | 77篇 |
2021年 | 121篇 |
2020年 | 166篇 |
2019年 | 230篇 |
2018年 | 227篇 |
2017年 | 234篇 |
2016年 | 257篇 |
2015年 | 170篇 |
2014年 | 386篇 |
2013年 | 612篇 |
2012年 | 329篇 |
2011年 | 473篇 |
2010年 | 465篇 |
2009年 | 647篇 |
2008年 | 595篇 |
2007年 | 641篇 |
2006年 | 536篇 |
2005年 | 481篇 |
2004年 | 399篇 |
2003年 | 430篇 |
2002年 | 394篇 |
2001年 | 268篇 |
2000年 | 298篇 |
1999年 | 280篇 |
1998年 | 239篇 |
1997年 | 225篇 |
1996年 | 137篇 |
1995年 | 76篇 |
1994年 | 70篇 |
1993年 | 40篇 |
1992年 | 36篇 |
1991年 | 24篇 |
1990年 | 18篇 |
1989年 | 19篇 |
1988年 | 19篇 |
1987年 | 7篇 |
1986年 | 4篇 |
1985年 | 17篇 |
1984年 | 27篇 |
1983年 | 14篇 |
1982年 | 23篇 |
1981年 | 14篇 |
1980年 | 20篇 |
1979年 | 11篇 |
1978年 | 8篇 |
1977年 | 6篇 |
1976年 | 3篇 |
1936年 | 4篇 |
排序方式: 共有9875条查询结果,搜索用时 15 毫秒
121.
提出了将哈密顿算符对角化的一种方法.围绕一维谐振子讨论了如何将哈密顿算符对角化、引进的是玻色算符还是费米算符的问题,并分析了能量量子化的原因及能量子与声子的区别. 相似文献
122.
Arne Barinka Stephan Dahlke Wolfgang Dahmen 《Advances in Computational Mathematics》2006,24(1-4):5-34
Recently adaptive wavelet methods have been developed which can be shown to exhibit an asymptotically optimal accuracy/work
balance for a wide class of variational problems including classical elliptic boundary value problems, boundary integral equations
as well as certain classes of noncoercive problems such as saddle point problems. A core ingredient of these schemes is the
approximate application of the involved operators in standard wavelet representation. Optimal computational complexity could
be shown under the assumption that the entries in properly compressed standard representations are known or computable in
average at unit cost. In this paper we propose concrete computational strategies and show under which circumstances this assumption
is justified in the context of elliptic boundary value problems.
Dedicated to Charles A. Micchelli on the occasion of his 60th birthday
Mathematics subject classifications (2000) 41A25, 41A46, 65F99, 65N12, 65N55.
This work has been supported in part by the Deutsche Forschungsgemeinschaft SFB 401, the first and third author are supported
in part by the European Community's Human Potential Programme under contract HPRN-CT-202-00286 (BREAKING COMPLEXITY). The
second author acknowledges the financial support provided through the European Union's Human Potential Programme, under contract
HPRN-CT-2002-00285 (HASSIP) and through DFG grant DA 360/4–1. 相似文献
123.
In this paper, we are concerned with the problem of stabilization for autonomous dynamical systems. We use theories in Liapunov stability and Lasalle stability theory and show that system (H) is stabilizable. 相似文献
124.
By means of the Leggett-Williams fixed-point theorem, criteria are developed for the existence of at least three positive solutions to the one-dimensional p-Laplacian boundary value problem, ((y′))′ + g(t)f(t,y) = 0, y(0) - B0(y′(0)) = 0, y(1) + B1(y′(1)) = 0, where (v) |v|p−2v, p > 1. 相似文献
125.
126.
Some Results behind Dividend Problems 总被引:1,自引:0,他引:1
Ming Zhou Li Wei Jun-yi Guo 《应用数学学报(英文版)》2006,22(4):681-686
We consider the basic dividend problem of the compound Poisson model with constant barrierstrategy.Some results concealed behind the dividend problem are made explicit in the present work.Differentmethods and some of which are firstly given in this paper.All these results presented certain direct relationshipbetween some important actuary variables in classical risk theory is also revealed. 相似文献
127.
The objective of this paper is to investigate the role of the set of irrational numbers as the codomain of order-preserving
functions defined on topological totally preordered sets. We will show that although the set of irrational numbers does not
satisfy the Debreu property it is still nonetheless true that any lower (respectively, upper) semicontinuous total preorder
representable by a real-valued strictly isotone function (semicontinuous or not) also admits a representation by means of
a lower (respectively, upper) semicontinuous strictly isotone function that takes values in the set of irrational numbers.
These results are obtained by means of a direct construction. Moreover, they can be related to Cantor’s characterization of the real line to obtain much more general results on the semicontinuous
Debreu properties of a wide family of subsets of the real line.
相似文献
128.
设E是自反的Banach空间,T∶E→2E是极大单调算子.T-10≠.令x0∈E,yn=(J λnT)-1xn en,xn 1=J-1(αnJxn (1-αn)Jyn),n≥0,λn>0,αn∈[0,1],本文研究了{xn}收敛性. 相似文献
129.
一类多线性积分算子的端点有界性 总被引:3,自引:0,他引:3
本文对一类相关于非卷积型算子的多线性算子,证明了其在端点情形上的有界性,该算子包括Littlewood-Paley算子和Marcinkiewicz算子. 相似文献
130.
Jipu Ma 《中国科学A辑(英文版)》1997,40(12):1233-1238
A generalized dimension is further developed. Here subtraction and addition of two generalized dimensions are defined, so
that the operations: ∞ ± n = ∞, ∞ + ∞ = ∞, which used to play an inflexible role, are refined and moreover, ∞ - ∞, which used
to be meaningless, is done in sense. Then generalized index for semi-Fred-holm operators is developed to wholeB(H), i.e. all of bounded linear operators in Hilbert spaceH. Theorem 2.2 is proved with an example, which is in contradiction to a known proposition for semi-Fredholm operators in form,
practically a refined result of the known proposition. Then, it is proved thatB(H) is the union of countably many disjoint arewise connected sets over all the generalized dimensions ofB(H).
Project supported by the National Natural Science Foundation of China 相似文献