全文获取类型
收费全文 | 68910篇 |
免费 | 5107篇 |
国内免费 | 6618篇 |
专业分类
化学 | 26243篇 |
晶体学 | 286篇 |
力学 | 6453篇 |
综合类 | 1225篇 |
数学 | 25269篇 |
物理学 | 21159篇 |
出版年
2023年 | 579篇 |
2022年 | 1155篇 |
2021年 | 1278篇 |
2020年 | 1336篇 |
2019年 | 1620篇 |
2018年 | 1293篇 |
2017年 | 1536篇 |
2016年 | 1738篇 |
2015年 | 1601篇 |
2014年 | 2302篇 |
2013年 | 4378篇 |
2012年 | 2646篇 |
2011年 | 3019篇 |
2010年 | 2611篇 |
2009年 | 3723篇 |
2008年 | 4158篇 |
2007年 | 4364篇 |
2006年 | 4106篇 |
2005年 | 3481篇 |
2004年 | 3193篇 |
2003年 | 3257篇 |
2002年 | 2987篇 |
2001年 | 2528篇 |
2000年 | 2477篇 |
1999年 | 2217篇 |
1998年 | 2089篇 |
1997年 | 1708篇 |
1996年 | 1525篇 |
1995年 | 1377篇 |
1994年 | 1280篇 |
1993年 | 1093篇 |
1992年 | 1064篇 |
1991年 | 823篇 |
1990年 | 683篇 |
1989年 | 591篇 |
1988年 | 543篇 |
1987年 | 426篇 |
1986年 | 365篇 |
1985年 | 428篇 |
1984年 | 426篇 |
1983年 | 208篇 |
1982年 | 341篇 |
1981年 | 400篇 |
1980年 | 301篇 |
1979年 | 291篇 |
1978年 | 223篇 |
1977年 | 205篇 |
1976年 | 154篇 |
1974年 | 109篇 |
1973年 | 104篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
72.
On Quantum Team Games 总被引:2,自引:0,他引:2
E. Ahmed M. F. Elettreby A. S. Hegazi 《International Journal of Theoretical Physics》2006,45(5):880-886
Recently Liu and Simaan (2004) convex static multi-team classical games have been introduced. Here they are generalized to both nonconvex, dynamic and quantum games. Puu's incomplete information dynamical systems are modified and applied to Cournot team game. The replicator dynamics of the quantum prisoner's dilemma game is also studied. 相似文献
73.
Daniel B. Szyld 《Numerical Algorithms》2006,42(3-4):309-323
Given an oblique projector P on a Hilbert space, i.e., an operator satisfying P
2=P, which is neither null nor the identity, it holds that ||P|| = ||I –P||. This useful equality, while not widely-known, has been proven repeatedly in the literature. Many published proofs are reviewed, and simpler ones are presented. 相似文献
74.
给出2005年全国部分高校研究生数学建模竞赛D题的研究背景,对参赛论文作了简要评注,并提供了一种参考解答. 相似文献
75.
A. D. Rogers 《Acta Mathematica Hungarica》2006,110(1-2):13-21
Summary A lower bound is established for the strip discrepancy of a broad class of point distributions. The bound implies unbounded
strip discrepancy for equally weighted point distributions under favorable conditions. The methods of proof use notions from
integral geometry. 相似文献
76.
We show that the difference between the Schrödinger uncertainty relations (UR) and the Heisenberg UR is fundamental. We propose a modified version of stochastic mechanics that allows clearly demonstrating that the contributions from the anticommutator and the commutator to the Schrödinger UR are equally important. A classification of quantum states minimizing the Schrödinger UR at an arbitrary instant is proposed. We show that the correlation of the coordinate and momentum fluctuations in such correlated-coherent states (CCS) is largely determined by the contributions from not only the commutator but also the anticommutator of the corresponding operators. We demonstrate that the character of this correlation changes qualitatively in time from the antiphase correlation typical for the Heisenberg UR to the inphase correlation for which the contribution from the anticommutator is decisive. We comparatively analyze properties of a free microparticle and a quantum oscillator in CCS and show that the CCS correspond to traveling-standing de Broglie waves in both models. 相似文献
77.
Kasper K. Berthelsen Jesper Møller 《Bulletin of the Brazilian Mathematical Society》2002,33(3):351-367
This primer provides a self-contained exposition of the case where spatial birth-and-death processes are used for perfect
simulation of locally stable point processes. Particularly, a simple dominating coupling from the past (CFTP) algorithm and
the CFTP algorithms introduced in [13], [14], and [5] are studied. Some empirical results for the algorithms are discussed.
Received: 30 June 2002 相似文献
78.
79.
A FUNDAMENTAL SOLUTION FOR THE LAPLACE OPERATOR ON THE QUATERNIONIC HEISENBERG GROUP 总被引:2,自引:0,他引:2
朱理 《数学物理学报(B辑英文版)》2002,22(3)
In this paper, the author studies the Laplace operator on the quaternionic Heisenberg group, construct a fundamental solution for it and use this solution to prove the Lp-boundedness and the weak (1-1) boundedness of certain singular convolution operators on the quaternionic Heisenberg group. 相似文献
80.
Taekyun Kim 《Journal of Mathematical Analysis and Applications》2002,273(1):236-242
The purpose of this paper is to give a proof of Kummer type congruence for the q-Bernoulli numbers of higher order, which is an answer to a part of the problem in a previous publication (see Indian J. Pure Appl. Math. 32 (2001) 1565-1570). 相似文献