全文获取类型
收费全文 | 2694篇 |
免费 | 170篇 |
国内免费 | 166篇 |
专业分类
化学 | 907篇 |
晶体学 | 13篇 |
力学 | 185篇 |
综合类 | 36篇 |
数学 | 1180篇 |
物理学 | 709篇 |
出版年
2023年 | 17篇 |
2022年 | 20篇 |
2021年 | 23篇 |
2020年 | 43篇 |
2019年 | 53篇 |
2018年 | 46篇 |
2017年 | 61篇 |
2016年 | 54篇 |
2015年 | 47篇 |
2014年 | 70篇 |
2013年 | 185篇 |
2012年 | 108篇 |
2011年 | 112篇 |
2010年 | 102篇 |
2009年 | 148篇 |
2008年 | 137篇 |
2007年 | 160篇 |
2006年 | 162篇 |
2005年 | 140篇 |
2004年 | 128篇 |
2003年 | 143篇 |
2002年 | 123篇 |
2001年 | 97篇 |
2000年 | 85篇 |
1999年 | 82篇 |
1998年 | 42篇 |
1997年 | 65篇 |
1996年 | 51篇 |
1995年 | 51篇 |
1994年 | 36篇 |
1993年 | 35篇 |
1992年 | 41篇 |
1991年 | 30篇 |
1990年 | 29篇 |
1989年 | 23篇 |
1988年 | 30篇 |
1987年 | 28篇 |
1986年 | 23篇 |
1985年 | 18篇 |
1984年 | 28篇 |
1983年 | 9篇 |
1982年 | 23篇 |
1981年 | 18篇 |
1980年 | 16篇 |
1979年 | 17篇 |
1978年 | 9篇 |
1977年 | 16篇 |
1976年 | 8篇 |
1974年 | 11篇 |
1973年 | 7篇 |
排序方式: 共有3030条查询结果,搜索用时 15 毫秒
61.
利用Schur引理确定了角动量耦合的Clebsch-Gordan系数按照其定义所允许的任意程度,然后利用正交归一关系和相位知识,导出了Clebsch-Gordan系数的对称性. 相似文献
62.
63.
64.
Elie Leopold 《Numerical Algorithms》2007,44(4):347-366
In this paper, we give some new explicit relations between two families of polynomials defined by recurrence relations of
all order. These relations allow us to analyze, even in the Sobolev case, how some properties of a family of orthogonal polynomials
are affected when the coefficients of the recurrence relation and the order are perturbed. In a paper we have already given
a method which allows us to study the polynomials defined by a three-term recurrence relation. Also here some generalizations
are given. 相似文献
65.
R. Ferrini G. Guizzetti M. Patrini A. Parisini L. Tarricone B. Valenti 《The European Physical Journal B - Condensed Matter and Complex Systems》2002,27(4):449-458
In0.49Ga0.51P films, both undoped and doped n- and p-type (up to 1018 cm-3), were grown lattice matched on GaAs substrates, with different miscut angles, by Metal-Organic Vapour Phase Epitaxy (MOVPE)
at different temperatures. The shift of the fundamental gap E0, caused by “ordering effect” was measured as a function of temperature by photoluminescence. The complex refractive index
= n + ik and the dielectric function = ɛ
1 + iɛ
2 at room temperature were determined from 0.01 to 5.5 eV by using complementary data from fast-Fourier-transform far-infrared
(FFT-FIR), dispersive, and ellipsometric spectroscopies. The effect of the native oxide was accounted for and the self-consistency
of the optical functions was checked in the framework of the Kramers-Kronig causality relations. In the restrahlen region
the dielectric function was well fitted by classical Lorentz oscillators; in the transparent region below E0, the refractive index was modelled by a Sellmeier dispersion relation; in the interband region the dielectric function was
well reproduced by analytical lineshapes associated to seven critical points. Thus parametrized analytical expressions were
obtained for the optical functions all over the spectral range, without discontinuities, to be used in the modelling and characterization
of multi-layer structures, also on opaque substrates.
Received 13 December 2001 Published online 25 June 2002 相似文献
66.
变系数(2+1)维Broer-Kaup方程的精确解 总被引:15,自引:4,他引:15
利用齐次平衡原则,导出了变系数(2+1)维Broer-Kaup方程的B?cklund变换(BT),并由该BT,求出了(2+1)维Broer-Kaup方程的各种形式的精确解. 相似文献
67.
68.
This paper considers the exponential decay of the solution to a damped semilinear wave equation with variable coefficients in the principal part by Riemannian multiplier method. A differential geometric condition that ensures the exponential decay is obtained. 相似文献
69.
Jin Cheng Ching-Lung Lin Gen Nakamura 《Proceedings of the American Mathematical Society》2005,133(8):2359-2367
In this paper we prove the following kind of unique continuation property. That is, the zero on each geodesic of the solution in a real analytic hypersurface for second order anisotropic hyperbolic systems with real analytic coefficients can be continued along this curve.
70.
在群链G G_1 G_2中,把两个子群的IR(不可约表示)基相乘,然后把乘积基耦合成IR基,耦合系数我们称之为母分系数。本文把陈金全创立的本征函数法用于计算空间群的群链O_h~7 O~4 T~2的母分系数,计算的结果显示母分系数是满足正交关系,同时也说明此方法是适用的。 相似文献