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   2105篇
  免费   57篇
  国内免费   4篇
化学   1620篇
晶体学   22篇
力学   38篇
数学   143篇
物理学   343篇
  2023年   14篇
  2022年   30篇
  2021年   80篇
  2020年   57篇
  2019年   59篇
  2018年   60篇
  2017年   56篇
  2016年   97篇
  2015年   74篇
  2014年   80篇
  2013年   132篇
  2012年   109篇
  2011年   148篇
  2010年   80篇
  2009年   92篇
  2008年   105篇
  2007年   95篇
  2006年   86篇
  2005年   88篇
  2004年   49篇
  2003年   50篇
  2002年   54篇
  2001年   26篇
  2000年   29篇
  1999年   28篇
  1998年   30篇
  1997年   19篇
  1996年   19篇
  1995年   17篇
  1994年   12篇
  1992年   10篇
  1991年   12篇
  1989年   10篇
  1988年   11篇
  1987年   10篇
  1986年   10篇
  1985年   10篇
  1984年   13篇
  1982年   8篇
  1981年   13篇
  1979年   9篇
  1978年   12篇
  1977年   12篇
  1976年   10篇
  1975年   9篇
  1974年   8篇
  1973年   23篇
  1972年   11篇
  1970年   14篇
  1969年   8篇
排序方式: 共有2166条查询结果,搜索用时 15 毫秒
1.
Journal of Applied Spectroscopy - Aqueous solutions of human hemoglobin have been studied by the multi-angle static light scattering method. The tendency of sickle-shaped erythrocytes to aggregate...  相似文献   
2.
3.
Riemannian manifolds for which a natural curvature operator has constant eigenvalues on circles are studied. A local classification in dimensions two and three is given. In the 3-dimensional case one gets all locally symmetric spaces and all Riemannian manifolds with the constant principal Ricci curvatures r 1 = r 2 = 0, r 3= 0 , which are not locally homogeneous, in general.  相似文献   
4.
Microwave discharges produced by travelling/standing electromagnetic waves have drawn considerable attention in recent years due to their wide application in microelectronic industry. Here are presented the axial distributions of the electrons and ions as well as those of excited atoms in an argon microwave discharge at a low gas pressure (400 mTorr) sustained by a 2.45 GHz travelling dipolar electromagnetic wave. The numerical calculations are based on a self-consistent kinetic-electrodynamic model and the results obtained are in a good agreement with the experimental data. The model yields also the magnitude of the wave power sustaining the discharge and the axial profiles of all electromagnetic-wave characteristics and the axial distribution of the neutral gas temperature.  相似文献   
5.
It is demonstrated theoretically that the initial (both elastic and viscous) magnetic susceptibility components for nanocrystalline magnets caused by the processes of rotations (in the region of linear response) have resonant rather than relaxation character typical already for the susceptibility component caused by displacements of domain boundaries. __________ Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 6, pp. 88–92, June, 2007.  相似文献   
6.
The relation between the density of etch pits revealed in GaN by etching in a KOH/NaOH eutectic and the density of dislocations determined by transmission electron microscopy (TEM) is studied along with the relation between the density of dislocations and the density of dark spot defects observed in GaN by microcathodoluminescence (MCL) and electron-beam-induced current (EBIC). It is demonstrated that selective etching is a reliable rapid method for the determination of the type and density of dislocations in GaN in the range 106–108 cm?2, while MCL and EBIC can be used for the rapid nondestructive determination of the density of dislocations in the range 106–108 cm?2. It is also found that some deep electron and hole traps are related to dislocations.  相似文献   
7.
The photogyrotropic properties of several mordant yellow azo dyes in gelatin and polymer matrices that are in the normal state or exposed to circularly polarized light are investigated. A model explanation for the experimental data is given.  相似文献   
8.
9.
Multi-dimensional asymptotically quasi-Toeplitz Markov chains with discrete and continuous time are introduced. Ergodicity and non-ergodicity conditions are proven. Numerically stable algorithm to calculate the stationary distribution is presented. An application of such chains in retrial queueing models with Batch Markovian Arrival Process is briefly illustrated. AMS Subject Classifications Primary 60K25 · 60K20  相似文献   
10.
Translated from Aktual'nye Voprosy Prikladnoi Matematiki, pp. 222–228, 1989.  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