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   1653篇
  免费   54篇
  国内免费   12篇
化学   1325篇
晶体学   9篇
力学   23篇
数学   126篇
物理学   236篇
  2023年   10篇
  2022年   8篇
  2021年   25篇
  2020年   32篇
  2019年   22篇
  2018年   15篇
  2017年   13篇
  2016年   32篇
  2015年   44篇
  2014年   55篇
  2013年   88篇
  2012年   129篇
  2011年   143篇
  2010年   79篇
  2009年   51篇
  2008年   107篇
  2007年   109篇
  2006年   97篇
  2005年   111篇
  2004年   87篇
  2003年   71篇
  2002年   69篇
  2001年   29篇
  2000年   25篇
  1999年   14篇
  1998年   13篇
  1997年   12篇
  1996年   16篇
  1995年   15篇
  1994年   15篇
  1993年   15篇
  1992年   10篇
  1991年   9篇
  1990年   8篇
  1989年   9篇
  1988年   6篇
  1987年   6篇
  1986年   10篇
  1985年   19篇
  1984年   6篇
  1983年   5篇
  1982年   7篇
  1981年   7篇
  1977年   4篇
  1976年   4篇
  1975年   6篇
  1973年   10篇
  1969年   7篇
  1968年   4篇
  1943年   3篇
排序方式: 共有1719条查询结果,搜索用时 15 毫秒
1.
Suppose there exists a global solution u to the incompressible Navier–Stokes equations, such that u∈Ct(H?1/2). We prove that its H?1/2 norm goes to 0 at infinity. We next use this fact to control the L2t(H?3/2) norm of u, and finally we prove that such a solution is stable. To cite this article: I. Gallagher et al., C. R. Acad. Sci. Paris, Ser. I 334 (2002) 289–292.  相似文献   
2.
The effect of traffic noise on sleep of young adults in their homes   总被引:1,自引:0,他引:1  
The disturbance of sleep by traffic noise is a major problem area in noise pollution. Extensive laboratory tests using multichannel electroencephalograms (EEG) have been carried out by many workers to determine the general response of people when exposed to noise during sleep. An experimental technique for obtaining results in people's homes has been developed using a simplified one-channel EEG. The responses of six people in the age range 19-24 were measured. A significant correlation was found between sleep disturbance and traffic noise when the noise is expressed in EPNdB. In the home experiments the subjects appeared to be approximately 10 dB less sensitive to noises than laboratory subjects for similar noise exposure. There also appeared to be some adaptation to the noise exposure; however, only one subject was tested for a period of 20 days and was insufficient to give definite results on adaptation.  相似文献   
3.
4.
5.
We present in this paper a domain decomposition method to treat faults in geological basin modeling. The particularity of this model is that the faults whose widths are very small in comparison with the basin size, are not characterized as subdomains any more but as interfaces between sedimentary blocks. The originality of this work lies in the formulation of this new fault model and in the definition and the computation of the interface conditions between the subdomains. To cite this article: E. Flauraud et al., C. R. Mecanique 331 (2003).  相似文献   
6.
We investigate the self-energy of one electron coupled to a quantized radiation field by extending the ideas developed in Hainzl (Ann. H. Poincaré, in press). We fix an arbitrary cut-off parameter Λ and recover the α2-term of the self-energy, where α is the coupling parameter representing the fine structure constant. Thereby we develop a method which allows to expand the self-energy up to any power of α. This implies that perturbation theory in α is correct if Λ is fix. As an immediate consequence we obtain enhanced binding for electrons.  相似文献   
7.
A novel approach to H-phosphonates from hypophosphorous acid using a transfer hydrogenation process was developed. This method is atom-economical, environmentally friendly, catalytic, and efficient, leading easily to H-phosphonate monoesters or ammonium salt in moderate to good yields.  相似文献   
8.
9.
10.
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