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   390篇
  免费   4篇
化学   153篇
晶体学   3篇
力学   5篇
数学   18篇
物理学   215篇
  2022年   3篇
  2021年   5篇
  2020年   7篇
  2019年   13篇
  2018年   7篇
  2017年   7篇
  2016年   10篇
  2015年   4篇
  2014年   15篇
  2013年   14篇
  2012年   14篇
  2011年   18篇
  2010年   17篇
  2009年   15篇
  2008年   14篇
  2007年   16篇
  2006年   14篇
  2005年   10篇
  2004年   7篇
  2003年   12篇
  2002年   22篇
  2001年   12篇
  2000年   6篇
  1999年   6篇
  1998年   15篇
  1997年   5篇
  1996年   10篇
  1995年   7篇
  1994年   5篇
  1992年   4篇
  1991年   4篇
  1990年   6篇
  1989年   5篇
  1988年   3篇
  1987年   3篇
  1984年   4篇
  1981年   3篇
  1980年   4篇
  1979年   2篇
  1978年   10篇
  1977年   3篇
  1976年   6篇
  1975年   4篇
  1974年   6篇
  1973年   4篇
  1971年   2篇
  1970年   2篇
  1968年   2篇
  1967年   2篇
  1965年   2篇
排序方式: 共有394条查询结果,搜索用时 15 毫秒
41.
An equation of the Thomas-Fermi type has been obtained and solved numerically for a many-particle oscillator — a system of N electrons in a potential field of a harmonic oscillator. The electron density distribution in the system has been found. An analogous model has been formulated in the theory of atomic nucleus and used to calculate the charge density distribution in40Ca in good agreement with the available experimental data.Odessa Hydrometeorological Institute. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 7, pp. 66–72, July, 1992.  相似文献   
42.
43.
44.
On the basis of pseudopotential theory, within the framework of a formally accurate model perturbation theory of Rayleigh—Schrödinger type with a zero-approximation inoculating potential, the calculation of some diatomic alkali molecules in homo- and heteronuclear variants LiM (M = Li, Na, K, Rb, Cs, Fr) is considered. A local model potential of Gell-Mann type is adopted as the zero-approximation potential. The calculation results for the energy parameters — in particular, the energy of dissociation — are given; some of these results are obtained here for the first time. The calculation demonstrates the fundamental role of two basic second-order perturbation-theory effects in achieving acceptable accuracy: polarizational interaction of the valence particles through the core; and mutual screening of these particles.  相似文献   
45.
The oscillator strengths of dipole transitions between energy levels of the lowest configurations of ions of the Rb I isoelectronic sequence with nuclear charge Z=41–46 are calculated on the basis of the model potential method using an energy approach. For certain ions the reported data are published here for the first time. It is shown that the contribution of core polarization to the oscillator strength attains 15% for some transitions.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 1, pp. 89–92, January, 1996.  相似文献   
46.
47.
2,3,4-Trioxohexahydroazepine 4-phenylhydrazone with a 15N-labeled atom bonded to the phenyl fragment was obtained in order to establish its structure. It was established by means of the PMR spectra that this substance is a mixture of syn and anti isomers of the hydrazone form. 2,3,4-Trioxohexahydroazepine 3-phenylhydrazone was isolated when an attempt was made to indolize the 4-phenylhydrazone. Both hydrazones react with phenylhydrazine to give the same 2,3,4-trioxohexahydroazepine 3,4-bis(phenylhydrazone). Derivatives involving the carbonyl group were obtained for both hydrazones, and the conditions for their indolization were studied, as a result of which a number of azepino[4,5-b]indole derivatives were synthesized.See [1] for communication 32.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 954–960, July, 1979.  相似文献   
48.
The necessity and possibility of taking into account the strain-rate dependence of the plastic strength in deriving mathematical models of the flow of heavily filled polymer systems is demonstrated.  相似文献   
49.
50.
We propose a method of constructing the images of the fundamental solutions in the space of the Laplace transform with respect to time, leading to simple formulas. The method is illustrated using three dynamical problems: planar deformation for an anisotropic body; flexural vibrations of an anisotropic plate; and vibrations of a shallow isotropic shell of arbitrary Gaussian curvature. Quadrature formulas are given for computing the values of the fundamental solutions. We give a new interpretation and a new method of computing the values of the special functions used in the construction of singular solutions in problems of the static theory of shells. Translated fromTeoreticheskaya i Prikladnaya Mekhanika, No. 23, 1992, pp. 86–92.  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