全文获取类型
收费全文 | 400722篇 |
免费 | 7891篇 |
国内免费 | 5421篇 |
专业分类
化学 | 192989篇 |
晶体学 | 6203篇 |
力学 | 21947篇 |
综合类 | 323篇 |
数学 | 58821篇 |
物理学 | 133751篇 |
出版年
2021年 | 3480篇 |
2020年 | 3909篇 |
2019年 | 4325篇 |
2018年 | 12599篇 |
2017年 | 13039篇 |
2016年 | 10361篇 |
2015年 | 5295篇 |
2014年 | 7221篇 |
2013年 | 14602篇 |
2012年 | 15800篇 |
2011年 | 24808篇 |
2010年 | 16521篇 |
2009年 | 16528篇 |
2008年 | 21653篇 |
2007年 | 24478篇 |
2006年 | 11749篇 |
2005年 | 15847篇 |
2004年 | 12213篇 |
2003年 | 11398篇 |
2002年 | 9811篇 |
2001年 | 9446篇 |
2000年 | 7402篇 |
1999年 | 5688篇 |
1998年 | 4951篇 |
1997年 | 4642篇 |
1996年 | 4588篇 |
1995年 | 4071篇 |
1994年 | 4058篇 |
1993年 | 4069篇 |
1992年 | 4157篇 |
1991年 | 4361篇 |
1990年 | 4094篇 |
1989年 | 3980篇 |
1988年 | 3883篇 |
1987年 | 3803篇 |
1986年 | 3598篇 |
1985年 | 4654篇 |
1984年 | 4849篇 |
1983年 | 3937篇 |
1982年 | 4148篇 |
1981年 | 3988篇 |
1980年 | 3856篇 |
1979年 | 4085篇 |
1978年 | 4196篇 |
1977年 | 4023篇 |
1976年 | 4246篇 |
1975年 | 3834篇 |
1974年 | 3856篇 |
1973年 | 3957篇 |
1972年 | 2889篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
941.
S. B. Bushuk Yu. A. Kal'vinkovskaya A. N. Rubinov 《Journal of Applied Spectroscopy》2004,71(2):291-294
Capture of an ensemble of polymeric microspheres in a water suspension under the action of optical gradient forces in the field of interfering laser beams has been investigated for the case of two-, three-, and four-beam interference. The self-diffraction and diffraction of radiation on induced ordered spatial distribution of particles have been obtained. 相似文献
942.
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
943.
A. E. Mironov 《Functional Analysis and Its Applications》2005,39(3):240-243
We construct commuting rank 2 formally self-adjoint ordinary differential operators corresponding to a curve of genus 2. 相似文献
944.
We suggest a new, more global, approach to the study of geodesically equivalent metrics which is based on application of the theory of integrable geodesic flows. Bibliography: 17 titles. 相似文献
945.
A generalization of the Bloembergen-Shen model to Raman active molecules with an arbitrary number of normal modes was suggested. The generalized model was used to study Raman echo signal characteristics when a system of molecules was excited by pulses of widths up to one period of optical oscillations. It was shown that a large number of echo responses on Stokes and anti-Stokes components could arise even under a two-pulse action in a continuous monochromatic pumping field. The number of echo responses depended on the number of molecular normal modes and the geometry of measurements. At small exciting pulse “areas,” the echo responses whose Stokes and anti-Stokes components corresponded to normal vibrational modes of a molecule had the highest intensity, whereas the components formed by normal mode combinations were strongly suppressed. 相似文献
946.
947.
Data on the proteinase complex from Carica papaya latex were reviewed. The properties and applications of the domestic preparation cucumazyme and known medicinal preparations based on papaya proteinases (caripazyme, lecozyme, lecopain) were compared. 相似文献
948.
M. De Falco F. De Giovanni C. Musella R. Schmidt 《Rendiconti del Circolo Matematico di Palermo》2003,52(1):70-76
A subgroupH of a groupG is said to bepermutable ifHX=XH for every subgroupX ofG. In this paper the structure of groups in which every subgroup either is abelian or permutable is investigated.
This work was done while the last author was visiting the University of Napoli Federico II. He thanks the “Dipartimento di
Matematica e Applicazioni” for its financial support. 相似文献
949.
P. V. Yagodovskii 《Journal of Mathematical Sciences》2003,113(5):728-730
A linear deformation of a discrete group G is a special deformation of the group algebra of G resulting in the group algebra of a multivalued group. Basic results on linear deformations are presented. Bibliography: 5 titles. 相似文献
950.
We prove that given a simply connected compact manifold M and a
closed manifold N, any map in the Sobolev space W
1,2(M,N) can be
approximated weakly by smooth maps between M and N.
Submitted: September 2002, Final version: November 2002. 相似文献