首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   309篇
  免费   1篇
化学   111篇
晶体学   1篇
力学   8篇
数学   66篇
物理学   124篇
  2023年   2篇
  2020年   3篇
  2019年   4篇
  2018年   2篇
  2017年   9篇
  2016年   8篇
  2015年   6篇
  2014年   9篇
  2013年   13篇
  2012年   14篇
  2011年   21篇
  2010年   21篇
  2009年   7篇
  2008年   3篇
  2007年   4篇
  2006年   9篇
  2005年   5篇
  2004年   9篇
  2003年   6篇
  2002年   9篇
  2001年   2篇
  2000年   2篇
  1999年   2篇
  1998年   5篇
  1997年   8篇
  1995年   3篇
  1992年   4篇
  1990年   7篇
  1989年   4篇
  1988年   6篇
  1987年   7篇
  1986年   3篇
  1984年   5篇
  1983年   4篇
  1982年   3篇
  1981年   8篇
  1980年   5篇
  1979年   2篇
  1978年   3篇
  1977年   4篇
  1976年   6篇
  1975年   7篇
  1974年   6篇
  1973年   4篇
  1972年   7篇
  1971年   5篇
  1970年   5篇
  1969年   2篇
  1968年   5篇
  1967年   7篇
排序方式: 共有310条查询结果,搜索用时 0 毫秒
31.
Russian Journal of Organic Chemistry -  相似文献   
32.
Studies of the photoluminescence spectra of spatially indirect excitons in coupled quantum wells revealed that the emission has a directional pattern dependent on the external electric field and pumping power. The experimentally detected correlation between the spectral emission parameters of spatially indirect excitons, namely, the concentration (phase state) of such excitons, the line half-width, the degree of linear polarization, and the existence of a directional pattern, permits a suggestion that the spontaneous photoluminescence of spatially indirect excitons in the condensed state is of a coherent nature.  相似文献   
33.
34.
Tri- and tetrasubstituted tetrahydropyranes fused to one and two heterocycles with various functional groups (COOEt, Br, MeC=CH2) were synthesized in stereoselective fashion by reactions of syn- and anti-1-R-2-(4-bromophenyl)-5-methylhex-4-en-1-ols (R = Bu, PhCH2) with trifluoromethanesulfonic acid, aldehydes in the presence of boron trifluoride–diethyl ether complex (Prins reaction), and salicylaldehydes in the presence of trimethyl orthoformate and p-toluenesulfonic acid. The obtained compounds were brought into Suzuki coupling with thiofen-2-ylboronic acid, hydrolysis, and reduction of the ester group with lithium tetrahydridoaluminate. The resulting carboxylic acid was converted to carboxamide, and the alcohol was oxidized to aldehyde which was converted to oxime. The steric configuration of substituents remained unchanged in all chemical transformations.  相似文献   
35.
Russian Journal of Organic Chemistry - Stereoselective synthesis of anti-2-aryl-4-en-1-ols from the corresponding syn isomers was accomplished with 71–83% yields via the Mitsunobu reaction.  相似文献   
36.
A universal mechanism underlying generalized synchronization conditions in unidirectionally coupled stochastic oscillators is considered. The consideration is carried out in the framework of a modified system with additional dissipation. The approach developed is illustrated with model examples. The conclusion is reached that two types of the behavior of nonlinear dynamic systems known as generalized synchronization and noise-induced synchronization, which are viewed as different phenomena, actually represent a unique type of the synchronous behavior of stochastic oscillators and are caused by the same mechanism.  相似文献   
37.
We propose a diagram theory around the atomic limit for the single-impurity Anderson model in which the strongly correlated impurity electrons hybridize with free (uncorrelated) conduction electrons. Using this diagram approach, we prove a linked-cluster theorem for the vacuum diagrams and derive Dyson-type equations for localized and conduction electrons and the corresponding equations for mixed propagators. The system of equations can be closed by summing an infinite series of ladder diagrams containing irreducible Green’s functions. The result allows discussing resonances associated with quantum transitions at the impurity site. __________ Translated from Teoreticheskaya i Matematicheskaya Fizika, Vol. 155, No. 3, pp. 474–497, June, 2008.  相似文献   
38.
39.
40.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号