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   541927篇
  免费   6912篇
  国内免费   2603篇
化学   279124篇
晶体学   7820篇
力学   26785篇
综合类   84篇
数学   69536篇
物理学   168093篇
  2021年   5543篇
  2020年   6123篇
  2019年   6772篇
  2018年   8906篇
  2017年   8975篇
  2016年   12291篇
  2015年   6859篇
  2014年   11156篇
  2013年   24529篇
  2012年   19540篇
  2011年   23002篇
  2010年   17222篇
  2009年   17092篇
  2008年   21592篇
  2007年   21305篇
  2006年   19319篇
  2005年   17289篇
  2004年   15961篇
  2003年   14362篇
  2002年   14237篇
  2001年   15038篇
  2000年   11628篇
  1999年   9042篇
  1998年   7792篇
  1997年   7622篇
  1996年   7122篇
  1995年   6421篇
  1994年   6399篇
  1993年   6138篇
  1992年   6477篇
  1991年   6950篇
  1990年   6668篇
  1989年   6552篇
  1988年   6382篇
  1987年   6179篇
  1986年   5908篇
  1985年   7450篇
  1984年   7805篇
  1983年   6549篇
  1982年   6833篇
  1981年   6345篇
  1980年   6012篇
  1979年   6512篇
  1978年   6744篇
  1977年   6632篇
  1976年   6592篇
  1975年   6310篇
  1974年   6130篇
  1973年   6426篇
  1972年   4709篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
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   
52.
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   
53.
54.
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   
55.
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   
56.
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   
57.
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   
58.
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   
59.
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   
60.
Solar-driven interfacial vaporization by localizing solar-thermal energy conversion to the air−water interface has attracted tremendous attention. In the process of converting solar energy into heat energy, photothermal materials play an essential role. Herein, a flexible solar-thermal material di-cyan substituted 5,12-dibutylquinacridone (DCN−4CQA)@Paper was developed by coating photothermal quinacridone derivatives on the cellulose paper. The DCN−4CQA@Paper combines desired chemical and physical properties, broadband light-absorbing, and shape-conforming abilities that render efficient photothermic vaporization. Notably, synergetic coupling of solar-steam and solar-electricity technologies by integrating DCN−4CQA@Paper and the thermoelectric devices is realized without trade-offs, highlighting the practical consideration toward more impactful solar heat exploitation. Such solar distillation and low-grade heat-to-electricity generation functions can provide potential opportunities for fresh water and electricity supply in off-grid or remote areas.  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