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   1070篇
  免费   13篇
  国内免费   3篇
化学   467篇
晶体学   9篇
力学   27篇
数学   74篇
物理学   509篇
  2022年   13篇
  2021年   19篇
  2020年   25篇
  2019年   25篇
  2018年   38篇
  2017年   32篇
  2016年   32篇
  2015年   15篇
  2014年   29篇
  2013年   33篇
  2012年   38篇
  2011年   46篇
  2010年   42篇
  2009年   43篇
  2008年   49篇
  2007年   57篇
  2006年   50篇
  2005年   29篇
  2004年   39篇
  2003年   27篇
  2002年   28篇
  2001年   27篇
  2000年   23篇
  1999年   16篇
  1997年   10篇
  1996年   16篇
  1995年   10篇
  1994年   11篇
  1993年   12篇
  1990年   10篇
  1989年   10篇
  1987年   7篇
  1986年   9篇
  1985年   6篇
  1984年   9篇
  1983年   12篇
  1982年   9篇
  1981年   8篇
  1979年   14篇
  1978年   13篇
  1977年   6篇
  1975年   9篇
  1974年   16篇
  1973年   10篇
  1972年   12篇
  1971年   23篇
  1970年   10篇
  1969年   11篇
  1968年   9篇
  1967年   6篇
排序方式: 共有1086条查询结果,搜索用时 33 毫秒
1.
JETP Letters - The effect of static mechanical strain on the splitting of spin sublevels of color centers based on spin 3/2 silicon vacancies in silicon carbide at room temperature has been shown....  相似文献   
2.
It is shown that a change in the linear dimension of compacted UO2 in the sintering process is associated with its plastic yielding under the action of the forces of residual stress and capillary forces. From the curves of sintering of a fuel with doping admixtures in various gaseous media, its rate of creep is reduced.  相似文献   
3.
4.
Russian Journal of Coordination Chemistry - The electron density distributions obtained by the quantum-chemical (density functional theory) calculations and molecular invariom model in the trimeric...  相似文献   
5.
Journal of Structural Chemistry - A four-nuclear complex [Ag4(Lut3P)2(MeCN)2](BF4)4 is synthesized by treating tris[(6-methylpyridin-2-yl)methyl]phosphine (Lut3P) with AgBF4 in a MeCN solution. The...  相似文献   
6.
A novel luciferin from a bioluminescent Siberian earthworm Fridericia heliota was recently described. In this study, the Fridericia oxyluciferin was isolated and its structure elucidated. The results provide insight into a novel bioluminescence mechanism in nature. Oxidative decarboxylation of a lysine fragment of the luciferin supplies energy for light generation, while a fluorescent CompX moiety remains intact and serves as the light emitter.  相似文献   
7.
In a magnetohydrodynamic approximation, an investigation is made of the propagation of waves in a plasma, whose characteristic frequency is much less than the collision frequency of the electrons e –1. It is assumed that the magnetic field is sufficiently strong so that the equality ee1 will be satisfied, where e is the cyclotron frequency of the rotation of the electrons. With large magnetic Reynolds numbers (Rm1), which are characteristic for many astrophysical problems, this latter condition leads to a need to take account of dispersion effects connected with Hall currents, in the absence of Joule dissipation. The dispersion equation for the propagation of small perturbations is analyzed in the limiting cases of weak dispersion and of a wave propagating along the magnetic field. In the case of weak dispersion, an equation is derived for nonlinear waves. The solutions are found in the form of stationary solitons. The region of such solutions is analyzed. A typical example of a medium with Hall dispersion is an interplanetary plasma, in which the parameter ee is generally great.Translated from Izvestiya Akademii Nauk SSSR, Mekhanika Zhidkosti i Gaza, No. 3, pp. 108–113, May–June, 1974.  相似文献   
8.
9.
The unsteady two-dimensional laminar flow past a circular cylinder encased in a perforated sheath is numerically simulated. On the basis of the calculated results a technique for controlling the wake flow by diverting a portion of the flow from the forward stagnation point through internal ducts to orifices in the sheath located in the separation zone, is analyzed.  相似文献   
10.
Doklady Physics - The results of experiments in a low-turbulence subsonic wind tunnel confirming the possibility of a significant attenuation of the cross-flow velocity and the intensity of...  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