全文获取类型
收费全文 | 89788篇 |
免费 | 7702篇 |
国内免费 | 9329篇 |
专业分类
化学 | 34577篇 |
晶体学 | 391篇 |
力学 | 8486篇 |
综合类 | 1377篇 |
数学 | 32060篇 |
物理学 | 29928篇 |
出版年
2024年 | 140篇 |
2023年 | 753篇 |
2022年 | 1325篇 |
2021年 | 1701篇 |
2020年 | 1960篇 |
2019年 | 2164篇 |
2018年 | 1906篇 |
2017年 | 2247篇 |
2016年 | 2590篇 |
2015年 | 2352篇 |
2014年 | 3379篇 |
2013年 | 6229篇 |
2012年 | 3838篇 |
2011年 | 4419篇 |
2010年 | 3692篇 |
2009年 | 5130篇 |
2008年 | 5609篇 |
2007年 | 5822篇 |
2006年 | 5333篇 |
2005年 | 4517篇 |
2004年 | 4073篇 |
2003年 | 4098篇 |
2002年 | 3784篇 |
2001年 | 3153篇 |
2000年 | 3082篇 |
1999年 | 2759篇 |
1998年 | 2553篇 |
1997年 | 2091篇 |
1996年 | 1795篇 |
1995年 | 1619篇 |
1994年 | 1499篇 |
1993年 | 1302篇 |
1992年 | 1248篇 |
1991年 | 976篇 |
1990年 | 851篇 |
1989年 | 757篇 |
1988年 | 695篇 |
1987年 | 565篇 |
1986年 | 486篇 |
1985年 | 551篇 |
1984年 | 550篇 |
1983年 | 284篇 |
1982年 | 437篇 |
1981年 | 500篇 |
1980年 | 381篇 |
1979年 | 358篇 |
1978年 | 271篇 |
1977年 | 264篇 |
1976年 | 206篇 |
1973年 | 138篇 |
排序方式: 共有10000条查询结果,搜索用时 656 毫秒
111.
DING Bin-Gang ZHANG Da-Li LU Ding-Hui 《理论物理通讯》2006,46(1):113-118
We calculate the binding energies of Ni, Cu, Xe, Cs, Pt, Au, Np, Pu isotope chains using two interaction parameter sets NL-3 and NL-Z, and compared the relative errors of the even-even nuclei with those of odd-even nuclei and odd-odd nuclei. We find that the errors of binding energy of odd-even and odd-odd nuclei are not bigger than the one of even-even nuclei. The result shows that comparing with even-even nuclei, there is no systematic error and approximation in the calculations of the binding energy of odd-even and odd-odd nuclei with relativistic mean-field theory. In addition, the result is explained theoretically. 相似文献
112.
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
113.
A. V. Bobylev 《Journal of statistical physics》2006,124(2-4):371-399
It is well-known that the classical Chapman-Enskog procedure does not work at the level of Burnett equations (the next step after the Navier-Stokes equations). Roughly speaking, the reason is that the solutions of higher equations of hydrodynamics (Burnett's, etc.) become unstable with respect to short-wave perturbations. This problem was recently attacked by several authors who proposed different ways to deal with it. We present in this paper one of possible alternatives. First we deduce a criterion for hyperbolicity of Burnett equations for the general molecular model and show that this criterion is not fulfilled in most typical cases. Then we discuss in more detail the problem of truncation of the Chapman-Enskog expansion and show that the way of truncation is not unique. The general idea of changes of coordinates (based on analogy with the theory of dynamical systems) leads finally to nonlinear Hyperbolic Burnett Equations (HBEs) without using any information beyond the classical Burnett equations. It is proved that HBEs satisfy the linearized H-theorem. The linear version of the problem is studied in more detail, the complete Chapman-Enskog expansion is given for the linear case. A simplified proof of the Slemrod identity for Burnett coefficients is also given. 相似文献
114.
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
115.
Cai Xiaochun 《Annals of Differential Equations》2006,22(1):1-6
In this paper, we apply a critical point theorem and obtain the condition for the existence of three solutions to two-point boundary value problem of a second order nonlinear difference equation. 相似文献
116.
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
117.
We propose a framework, based on classical mixture theory, to describe the isothermal flow of an incompressible fluid through a deformable inelastic porous solid. The modeling of the behavior of the inelastic solid takes into account changes in the elastic response due to evolution in the microstructure of the material. We apply the model to a compression layer problem. The mathematical problem generated by the model is a free boundary problem. 相似文献
118.
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
119.
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
120.