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   562301篇
  免费   21082篇
  国内免费   1342篇
化学   316554篇
晶体学   7666篇
力学   26952篇
综合类   17篇
数学   69274篇
物理学   164262篇
  2021年   7238篇
  2020年   9693篇
  2019年   8222篇
  2018年   10598篇
  2017年   9133篇
  2016年   16630篇
  2015年   11166篇
  2014年   14900篇
  2013年   28154篇
  2012年   21200篇
  2011年   22809篇
  2010年   19464篇
  2009年   19229篇
  2008年   21629篇
  2007年   21225篇
  2006年   18793篇
  2005年   16746篇
  2004年   15587篇
  2003年   14056篇
  2002年   13925篇
  2001年   14777篇
  2000年   11380篇
  1999年   8794篇
  1998年   7622篇
  1997年   7518篇
  1996年   6979篇
  1995年   6364篇
  1994年   6334篇
  1993年   6191篇
  1992年   6445篇
  1991年   6924篇
  1990年   6609篇
  1989年   6536篇
  1988年   6386篇
  1987年   6188篇
  1986年   5911篇
  1985年   7457篇
  1984年   7827篇
  1983年   6592篇
  1982年   6886篇
  1981年   6406篇
  1980年   6094篇
  1979年   6592篇
  1978年   6831篇
  1977年   6781篇
  1976年   6753篇
  1975年   6476篇
  1974年   6315篇
  1973年   6525篇
  1972年   4844篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
We investigate the possibility of phantom crossing in the dark energy sector and the solution for the Hubble tension between early and late universe observations. We use robust combinations of different cosmological observations, namely the Cosmic Microwave Background (CMB), local measurement of Hubble constant (H0), Baryon Acoustic Oscillation (BAO) and SnIa for this purpose. For a combination of CMB+BAO data that is related to early universe physics, phantom crossing in the dark energy sector was confirmed at a 95% confidence level and we obtained the constraint H0=71.03.8+2.9 km/s/Mpc at a 68% confidence level, which is in perfect agreement with the local measurement by Riess et al. We show that constraints from different combinations of data are consistent with each other and all of them are consistent with phantom crossing in the dark energy sector. For the combination of all data considered, we obtained the constraint H0=70.25±0.78 km/s/Mpc at a 68% confidence level and the phantom crossing happening at the scale factor am=0.8510.031+0.048 at a 68% confidence level.  相似文献   
62.
Algebra and Logic - Unary functions definable in o-stable ordered groups of nonvaluational type are studied. Such functions are proved to be piecewise monotone and continuous.  相似文献   
63.
64.
Journal of Applied Mechanics and Technical Physics - A refined model of viscoelastic-plastic deformation of flexible plates with spatial reinforcement structures has been developed. Strains of the...  相似文献   
65.
Russian Physics Journal - A unified equation for the pressure drop in the apparatus with the stationary and fluidized granular layers is derived. The resulting recurrent equation is used to...  相似文献   
66.
Pentafluorosulfanyl (SF5)-containing compounds and corresponding analogs are a highly valuable class of fluorine-containing building blocks owing to their unique properties. The reason for that is the set of peculiar and tremendously beneficial characteristics they can impart on molecules once introduced onto them. Despite this, their application in distinct scientific fields remains modest, given the extremely harsh reaction conditions needed to access such compounds. The recent synthetic approaches via S−F, and C−SF5 bond formation as well as the use of SF5-containing building blocks embody a “stairway-to-heaven” loophole in the synthesis of otherwise-inaccessible chemical scaffolds only a few years ago. Herein, we report and evaluate the properties of the SF5 group and analogs, by summarizing synthetic methodologies available to access them as well as following applications in material science and medicinal chemistry since 2015.  相似文献   
67.
Filippov  A. N. 《Colloid Journal》2022,84(3):332-343
Colloid Journal - The capillary-osmosis and reverse-osmosis coefficients of an ion-exchange membrane have been calculated as the kinetic coefficients of the Onsager matrix within the thermodynamics...  相似文献   
68.
Ferrarini  A.  Finotello  A.  Salsano  G.  Auricchio  F.  Palombo  D.  Spinella  G.  Pane  B.  Conti  M. 《Acta Mechanica Sinica》2021,37(7):1192-1192
Acta Mechanica Sinica - A Correction to this paper has been published: https://doi.org/10.1007/s10409-021-01066-2  相似文献   
69.
Physics of the Solid State - The interference of excited and received by current antennae magnetoelastic waves counterpropagating in an yttrium iron garnet film is experimentally studied. It is...  相似文献   
70.
Journal of Experimental and Theoretical Physics - The studies of the topological properties of systems have recently been extended due to a new concept of higher-order topological insulators and...  相似文献   
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