全文获取类型
收费全文 | 386606篇 |
免费 | 3834篇 |
国内免费 | 1720篇 |
专业分类
化学 | 205423篇 |
晶体学 | 5884篇 |
力学 | 18150篇 |
综合类 | 70篇 |
数学 | 44447篇 |
物理学 | 118186篇 |
出版年
2020年 | 3440篇 |
2019年 | 4022篇 |
2018年 | 5499篇 |
2017年 | 5519篇 |
2016年 | 7616篇 |
2015年 | 4334篇 |
2014年 | 7145篇 |
2013年 | 16131篇 |
2012年 | 13260篇 |
2011年 | 15987篇 |
2010年 | 11939篇 |
2009年 | 11903篇 |
2008年 | 15012篇 |
2007年 | 15006篇 |
2006年 | 13737篇 |
2005年 | 12378篇 |
2004年 | 11404篇 |
2003年 | 10170篇 |
2002年 | 10073篇 |
2001年 | 11220篇 |
2000年 | 8453篇 |
1999年 | 6277篇 |
1998年 | 5295篇 |
1997年 | 5325篇 |
1996年 | 5117篇 |
1995年 | 4458篇 |
1994年 | 4633篇 |
1993年 | 4463篇 |
1992年 | 4908篇 |
1991年 | 5057篇 |
1990年 | 4823篇 |
1989年 | 4781篇 |
1988年 | 4651篇 |
1987年 | 4571篇 |
1986年 | 4505篇 |
1985年 | 5801篇 |
1984年 | 5900篇 |
1983年 | 4952篇 |
1982年 | 5133篇 |
1981年 | 4899篇 |
1980年 | 4503篇 |
1979年 | 5014篇 |
1978年 | 5184篇 |
1977年 | 5336篇 |
1976年 | 5413篇 |
1975年 | 4962篇 |
1974年 | 4988篇 |
1973年 | 5137篇 |
1972年 | 3907篇 |
1971年 | 3402篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
101.
102.
A. N. Zinoviev 《Journal of Mathematical Sciences》2004,124(1):4806-4821
The generalized Hilbert symbol in a cyclotomic extension of an absolutely unramified higher local field of characteristic 0 with a perfect last residue field of characteristic p > 2 is considered. Generalized Artin–Hasse and Iwasawa formulas are derived from an explicit Kummer Type Vostokov formula. Bibliography: 13 titles. 相似文献
103.
A semiclassical theory of electromagnetically induced transparency in a Bose-Einstein condensate is considered. A nonlinear Schrödinger equation that describes the interaction of the Bose-Einstein condensate with an electromagnetic field is derived. An analysis of the obtained solutions to this equation demonstrates a decrease in the group velocity of the light pulse. 相似文献
104.
Piryatinskiĭ Yu. P. Yaroshchuk O. V. Dolgov L. A. Bidna T. V. Enke D. 《Optics and Spectroscopy》2004,97(4):537-542
Optics and Spectroscopy - The fluorescence of the nematic liquid crystal n-butyl-n′-methoxyazoxybenzene (BMAOB) in the form of a layer and in porous glasses with pores of different diameter... 相似文献
105.
The projection approach is applied to construct and investigate an operator-difference scheme for fluid dynamics in Lagrangean variables which has first-order local approximation in the axisymmetric case near the symmetry axis. The scheme also has operator properties that make it suitable for rederiving and substantiating previous results, methods, and algorithms. 相似文献
106.
Glezer A.M. Blinova E.N. Pozdnyakov V.A. Shelyakov A.V. 《Journal of nanoparticle research》2003,5(5-6):551-560
Journal of Nanoparticle Research - It was shown that the thermoelastic martensite transformation B2 ? B19 inside nanoparticles surrounded by amorphous matrix in Ni–Ti–Cu alloys as... 相似文献
107.
108.
L. Yu. Kolotilina 《Journal of Mathematical Sciences》2004,121(4):2481-2507
In this paper, bounds and inequalities for the Perron root of a nonnegative matrix, extending and complementing the classical theorems of Frobenius and Ostrowski in terms of (deleted) row and column sums, are presented. All the results are derived by using the same approach, based on the monotonicity property of the Perron root. Bibliography: 12 titles. 相似文献
109.
Journal of Statistical Physics - 相似文献
110.
The results of optical study and quantum-chemical simulation of a conjugated organic system, 2-cyclooctylamino-5-nitropyridine (COANP)-fullerene, performed to determine its potential for application as a limiter of visible and near-IR laser radiation and as a material for diffraction elements in systems for reversible recording of optical information, are presented. Complexation between a COANP molecule and fullerene is considered as one of the main mechanisms responsible for the corresponding properties of this system. For the first time, nonlinear optical characteristics of COANP-C60 and COANP-C70 systems are comparatively studied and the intermolecular interaction between a COANP molecule and fullerene is analyzed on the quantum-chemical level. 相似文献