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   602篇
  免费   21篇
  国内免费   7篇
化学   419篇
晶体学   9篇
力学   5篇
数学   46篇
物理学   151篇
  2023年   7篇
  2022年   7篇
  2021年   4篇
  2020年   5篇
  2019年   10篇
  2017年   5篇
  2016年   10篇
  2015年   11篇
  2014年   10篇
  2013年   26篇
  2012年   21篇
  2011年   29篇
  2010年   23篇
  2009年   19篇
  2008年   28篇
  2007年   34篇
  2006年   35篇
  2005年   23篇
  2004年   31篇
  2003年   28篇
  2002年   23篇
  2001年   12篇
  2000年   11篇
  1999年   13篇
  1998年   18篇
  1997年   4篇
  1996年   8篇
  1995年   7篇
  1994年   5篇
  1993年   10篇
  1992年   10篇
  1989年   4篇
  1988年   9篇
  1987年   9篇
  1985年   4篇
  1984年   4篇
  1983年   5篇
  1982年   9篇
  1981年   7篇
  1979年   11篇
  1978年   8篇
  1977年   4篇
  1975年   3篇
  1974年   12篇
  1973年   3篇
  1970年   4篇
  1969年   8篇
  1968年   6篇
  1967年   11篇
  1966年   3篇
排序方式: 共有630条查询结果,搜索用时 125 毫秒
81.
82.
The number projected HFB wave function is analyzed in terms of particle pairs. It is found that the S(J = 0) and D(J = 2) pairs have dominant probabilities in this wave function before the occurrence of backbending, which is clarified from the behaviour of the O(J = 12) and M(J = 10) pairs arising from the i132 level. After backbending the wave function can be described mainly in terms of the O and M pairs plus the core made of S and D pairs.  相似文献   
83.
The Hartree-Fock approximation has been generalized to incorporate the nonadiabatic effect of molecular vibration previously by Tachibana et al. Here, we will derive the Hartree-Fock equation which reflects also the nonlinear effect of the infrared radiation field as well by using the Bloch-Nordsieck transformation which was discussed first by Nguyen-Dang and Bandrauk in the field of molecular physics. The Hartree-Fock equation reflects the non-adiabatic coupling between an electron and a molecular vibration and between the electron and a infrared radiation fields. The infrared radiation field also affects the dynamics of nuclear motion.Dedicated to Professor J. Koutecký on the occasion of his 65th birthday  相似文献   
84.
2-(2,3-anthracenedicarboximido)cyclohexane derivatives (AC) have been known as the evolutionary diastereomerizing reagents for enantiomer discrimination in HPLC with ODS. However, a substantial separation of diastereomers can be observed only at lower temperatures, such as -40 degrees C. Therefore, in this work, poly(octadecyl acrylate)-grafted silica, ODAn was applied as an alternative stationary phase to ODS for the separation of AC-derived diastereomers. As a result, complete separation was achieved even under the conventional condition: for example, methanol as the mobile phase and 0 degrees C as the column temperature. An investigation on the temperature dependency of the selectivity demonstrated that ODAn shows a remarkable increase in selectivity at temperatures below 30 degrees C, which almost agreed with the peak-top temperature of the endothermic peak in a DSC thermogram for ODA35 immersed in a mobile phase. The better separation would be derived from a highly ordered structure of ODAn and a carbonyl-pi interaction with AC-derived diastereomers.  相似文献   
85.
86.
Many theoretical contributions to nuclear magnetic moments are reviewed with major attention to core polarisation and meson exchange currents. Experimental evidence is drawn from light isobaric mirror nuclei. Relativistic and quark contributions to nuclear magnetic moments are estimated and discussed.  相似文献   
87.
An analysis of the nonlinear mixing of oppositely travelling surface plasmons on a semi-infinite metal is discussed within the framework of Maxwell's equations. Coupling to free-space radiation fields, and transverse bulk waves in the metal is predicted under certain conditions at the sum frequency of the two surface plasmons.  相似文献   
88.
The first discussion on ATR mode of surface magnon polaritons on semi- infinite YIG is presented for the Otto configuration (polyethylene-air-YIG geometry). Damping and the effect of retardation are included in the analysis. The thickness of the air layer appropriate for ATR measurements is determined.  相似文献   
89.
Off-axis holograms have been constructed with a double-heterojunction (Ga, Al) As-GaAs semiconductor laser, and image reconstruction has been accomplished using a semiconductor and a He-Ne laser. The reconstructed real images were quite clear, and the signal-to-noise ratio of those images was about 10. Experiments suggest that semiconductor lasers can successfully be applied to coherent optics.  相似文献   
90.
A theoretical treatment of the nonlinear mixing of two contra-directional surface plasmons of frequency ω1 and ω2 propagating on a semi-infinite metal surface is presented. The nonlinear interaction is analysed in terms of (a) nonlinear surface currents due to the breaking of inversion symmetry and the rapid variation of the normal electric field component at the surface, and (b) the nonlinear response of the electron gas in the bulk of the metal. These currents are treated as source terms for Maxwell's equations and electromagnetic fields are found which satisfy the driven wave equation and boundary conditions at the frequencies ω1 ± ω2. At the difference frequency ω1 ? ω2 the solution fields decay exponentially into both the air and the metal. However, at the sum frequency ω1 + ω2, coupling to transverse electromagnetic waves in both the air and the metal is predicted under appropriate wavevector and frequency conditions. The free-space radiation field is treated in detail and the feasibility of its experimental detection is discussed. No coupling to longitudinal bulk plasmons is predicted in this model of the nonlinear interaction.  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