全文获取类型
收费全文 | 377790篇 |
免费 | 3521篇 |
国内免费 | 1049篇 |
专业分类
化学 | 199517篇 |
晶体学 | 6406篇 |
力学 | 16464篇 |
综合类 | 15篇 |
数学 | 40361篇 |
物理学 | 119597篇 |
出版年
2021年 | 2871篇 |
2020年 | 3285篇 |
2019年 | 3657篇 |
2018年 | 4591篇 |
2017年 | 4573篇 |
2016年 | 6767篇 |
2015年 | 4242篇 |
2014年 | 6681篇 |
2013年 | 17012篇 |
2012年 | 12796篇 |
2011年 | 15547篇 |
2010年 | 10894篇 |
2009年 | 10779篇 |
2008年 | 13949篇 |
2007年 | 13976篇 |
2006年 | 13191篇 |
2005年 | 11934篇 |
2004年 | 11014篇 |
2003年 | 9903篇 |
2002年 | 9580篇 |
2001年 | 11381篇 |
2000年 | 8725篇 |
1999年 | 6755篇 |
1998年 | 5325篇 |
1997年 | 5338篇 |
1996年 | 5007篇 |
1995年 | 4665篇 |
1994年 | 4454篇 |
1993年 | 4192篇 |
1992年 | 5113篇 |
1991年 | 4976篇 |
1990年 | 4906篇 |
1989年 | 4725篇 |
1988年 | 4788篇 |
1987年 | 4816篇 |
1986年 | 4509篇 |
1985年 | 5884篇 |
1984年 | 6106篇 |
1983年 | 4905篇 |
1982年 | 5110篇 |
1981年 | 5166篇 |
1980年 | 4854篇 |
1979年 | 5203篇 |
1978年 | 5328篇 |
1977年 | 5429篇 |
1976年 | 5300篇 |
1975年 | 4887篇 |
1974年 | 4825篇 |
1973年 | 4933篇 |
1972年 | 3261篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
101.
102.
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
103.
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
104.
Russian Journal of General Chemistry - 相似文献
105.
In the present paper, the notion of norm series with respect to the norm residue symbol is generalized to high-dimensional local fields. Necessary and sufficient conditions for the existence of norm series are obtained. Bibliography: 12 titles.__________Translated from Zapiski Nauchnykh Seminarov POMI, Vol. 305, 2003, pp. 60–83. 相似文献
106.
107.
108.
Dinesh Topwal U. Manju Sugata Ray S. Raj D. D. Sarma S. R. Krishnakumar M. Bertolo S. La Rosa G. Cautero 《Journal of Chemical Sciences》2006,118(1):87-92
Disordered Sr2FeMoO6 shows a drastic reduction in saturation magnetization compared to highly ordered samples, moreover magnetization as a function
of the temperature for different disordered samples shows qualitatively different behaviours. We investigate the origin of
such diversity by performing spatially resolved photoemission spectroscopy on various disordered samples. Our results establish
that extensive electronic inhomogeneity, arising most probably from an underlying chemical inhomogeneity in disordered samples, is
responsible for the observed magnetic inhomogeneity. It is further pointed out that these inhomogeneities are connected with
composition fluctuations of the type Sr2Fe1+x
Mo1-x
O6 with Fe-rich (x > 0) and Mo-rich (x < 0) regions.
Dedicated to Prof J Gopalakrishnan on his 62nd birthday. 相似文献
109.
110.
An interconnection strategy with built-in adaptive controllersis presented which achieves synchronization of scalar linearsystems: the closed-loop network forces all outputs to followthe same signal asymptotically while maintaining the open-loopcharacteristics. In the design of the output feedback controllers,no knowledge of system parameters is assumed, but each systemmust have the same poles and be high-gain-stable. The proofof the main theorem relies critically on derived systems-theoreticresults and the special system topology as a network of interconnectedsystems. The topology is explained by first solving the simplerproblem of signal synchronization. 相似文献