全文获取类型
收费全文 | 84159篇 |
免费 | 2309篇 |
国内免费 | 285篇 |
专业分类
化学 | 50162篇 |
晶体学 | 508篇 |
力学 | 1720篇 |
综合类 | 14篇 |
数学 | 14718篇 |
物理学 | 19631篇 |
出版年
2023年 | 467篇 |
2022年 | 639篇 |
2021年 | 1202篇 |
2020年 | 1211篇 |
2019年 | 1192篇 |
2018年 | 1475篇 |
2017年 | 1390篇 |
2016年 | 2579篇 |
2015年 | 2172篇 |
2014年 | 2275篇 |
2013年 | 4642篇 |
2012年 | 4768篇 |
2011年 | 4954篇 |
2010年 | 3195篇 |
2009年 | 2914篇 |
2008年 | 4304篇 |
2007年 | 4140篇 |
2006年 | 3737篇 |
2005年 | 4071篇 |
2004年 | 3687篇 |
2003年 | 2940篇 |
2002年 | 2344篇 |
2001年 | 1844篇 |
2000年 | 1753篇 |
1999年 | 1225篇 |
1998年 | 981篇 |
1997年 | 927篇 |
1996年 | 1146篇 |
1995年 | 887篇 |
1994年 | 953篇 |
1993年 | 939篇 |
1992年 | 922篇 |
1991年 | 780篇 |
1990年 | 765篇 |
1989年 | 655篇 |
1988年 | 622篇 |
1987年 | 603篇 |
1986年 | 580篇 |
1985年 | 765篇 |
1984年 | 727篇 |
1983年 | 590篇 |
1982年 | 595篇 |
1981年 | 594篇 |
1980年 | 526篇 |
1979年 | 487篇 |
1978年 | 492篇 |
1977年 | 460篇 |
1976年 | 461篇 |
1974年 | 421篇 |
1973年 | 432篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
92.
Marí a J. Martí n Dragan Vukotic 《Proceedings of the American Mathematical Society》2006,134(6):1701-1705
We show that every composition operator which is an isometry of the Dirichlet space is induced by a univalent full map of the disk into itself that fixes the origin. This is an analogue of the Hardy space result for inner functions due to Nordgren. The proof relies on the Stone-Weierstrass theorem and the Riesz representation theorem.
93.
Zoltá n M. Balogh Marianna Csö rnyei 《Proceedings of the American Mathematical Society》2006,134(9):2667-2675
We give sufficient conditions for Sobolev and Lipschitz functions in terms of their lower scaled-oscillation. The sharpness of these conditions is shown by examples. Our examples also show that a Stepanov-type differentiability theorem does not hold under the boundedness assumption of the lower scaled-oscillation.
94.
The interferometric intensity patterns from a 2D shearing interferometer are shown and discussed. The intensity patterns can be obtained in two different approaches incorporating differential and extended wavefront controlled displacements. The reliable directional sensitivity of this interferometer allows the optimization of the measurement parameters to estimate the wavefront of the intensity patterns by regularization techniques. 相似文献
95.
J. C. Fabris S. V. B. Gonçalves P. E. de Souza 《General Relativity and Gravitation》2002,34(12):2111-2126
The mass power spectrum for a Universe dominated by the Chaplygin gas is evaluated numerically from scales of the order of the Hubble horizon to 100 Mpc. The results are compared with a pure baryonic Universe and a cosmological constant model. In all three cases, the spectrum increases with k, the wavenumber of the perturbations. The slope of the spectrum is higher for the baryonic model and smaller for the cosmological constant model, the Chaplygin gas interpolating these two models. The results are analyzed in terms of the sound velocity of the Chaplygin gas and the moment the Universe begins to accelerate. 相似文献
96.
97.
This paper attempts to develop a theory of sufficiency in the setting of non-commutative algebras parallel to the ideas in
classical mathematical statistics. Sufficiency of a coarse-graining means that all information is extracted about the mutual
relation of a given family of states. In the paper sufficient coarse-grainings are characterized in several equivalent ways
and the non-commutative analogue of the factorization theorem is obtained. As an application we discuss exponential families.
Our factorization theorem also implies two further important results, previously known only in finite Hilbert space dimension,
but proved here in generality: the Koashi-Imoto theorem on maps leaving a family of states invariant, and the characterization
of the general form of states in the equality case of strong subadditivity.
Supported by the EU Research Training Network Quantum Probability with Applications to Physics, Information Theory and Biology
and Center of Excellence SAS Physics of Information I/2/2005.
Supported by the Hungarian grant OTKA T032662 相似文献
98.
J. Carlos Díaz-Ramos Ramón Vázquez-Lorenzo 《Differential Geometry and its Applications》2006,24(4):433-442
Explicit examples of Osserman 4-manifolds with exactly two distinct eigenvalues of the Jacobi operators, α and β=4α≠0, are given. The former has multiplicity two and is a double root of the minimal polynomial of the Jacobi operators. 相似文献
99.
We present a new approach to study the convergence of Newton's method in Banach spaces, which relax the conditions appearing in the usual studies. The approach is based on the bound required for the second derivative of the operator involved. An application to a nonlinear integral equation is presented. 相似文献
100.
Balázs Szendröi 《Mathematische Zeitschrift》2002,240(2):233-241
This note shows that a certain toric quotient of the quintic Calabi-Yau threefold in provides a counterexample to a recent conjecture of Cox and Katz concerning nef cones of toric hypersurfaces.
Received: 8 February 2001; in final form: 17 September 2001 / Published online: 1 February 2002 相似文献