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   435篇
  免费   29篇
  国内免费   27篇
化学   187篇
综合类   2篇
数学   153篇
物理学   149篇
  2024年   1篇
  2023年   3篇
  2022年   3篇
  2021年   5篇
  2020年   13篇
  2019年   17篇
  2018年   13篇
  2017年   11篇
  2016年   11篇
  2015年   14篇
  2014年   14篇
  2013年   34篇
  2012年   19篇
  2011年   21篇
  2010年   16篇
  2009年   22篇
  2008年   32篇
  2007年   17篇
  2006年   24篇
  2005年   16篇
  2004年   22篇
  2003年   23篇
  2002年   21篇
  2001年   28篇
  2000年   29篇
  1999年   14篇
  1998年   10篇
  1997年   14篇
  1996年   9篇
  1995年   2篇
  1994年   1篇
  1993年   3篇
  1987年   1篇
  1986年   2篇
  1985年   1篇
  1982年   1篇
  1981年   1篇
  1980年   1篇
  1978年   2篇
排序方式: 共有491条查询结果,搜索用时 15 毫秒
41.
This paper deals with the relationship between the positivity of the Fock Toeplitz operators and their Berezin transforms. The author considers the special case of the bounded radial function φ(z) = a + be~(-α|z|~2)+ ce~(-β|z|~2), where a, b, c are real numbers and α, β are positive numbers. For this type of φ, one can choose these parameters such that the Berezin transform of φ is a nonnegative function on the complex plane, but the corresponding Toeplitz operator Tφ is not positive on the Fock space.  相似文献   
42.
 Analytical approximations to Hartree–Fock wave functions are constructed using Slater-type functions for the ground states of all 49 neutral atoms from Cs (Z=55) to Lr (Z=103). The current compilation is more extensive and more accurate than previous ones. The wave functions are available upon request from the authors or from the Web page http://www.unb.ca/chem/ajit/download.htm on the Internet. Received: 6 December 1999 / Accepted: 29 February 2000 / Published online: 12 May 2000  相似文献   
43.
44.
袁萍  刘欣生  张义军  颉录有  董晨钟 《物理学报》2002,51(11):2495-2502
用相对论多组态DiracFock方法,系统地计算了与闪电过程有关的NII离子2p2,2s2p3,2p3s,2p3p,2p3d组态能级之间的辐射跃迁概率,并由此推算出这些组态的35个能级的寿命.计算中考虑了相对论效应、电子关联、延迟效应等重要贡献.与已有的理论计算比较,目前计算的结果更接近最新实验值.据此,进一步给出了2p3d3F能级寿命新的理论预言值  相似文献   
45.
A new algebraic structure on a finite dimensional electronic Fock space is studied in detail. This structure is defined in terms of a certain multiplication of many electron wave functions and has close interrelation with coupled cluster and similar approaches. Its study simplifies the mathematical backgrounds of these approaches. Even more, it leads to relations that would be very difficult to derive using conventional technique. Formulas for action of the creation‐annihilation operators on products of state vectors are derived. Explicit expressions for action of simplest particle‐conserving products of the creation‐annihilation operators on powers of state vectors are given. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2006  相似文献   
46.
介绍Hardy-Sobolev空间和Fock空间及其算子与算子代数研究方面所做的工作,包括对这两类空间上几类特殊算子有界性、紧性、Fredholm性、指标理论、谱和本性谱、范数和本性范数、Schatten-p类的讨论,以及由它们所生成的C~*-代数的研究.  相似文献   
47.
48.
In this paper we investigate Leibniz algebras whose quotient Lie algebra is a naturally graded filiform Lie algebra nn,1. We introduce a Fock module for the algebra nn,1 and provide classification of Leibniz algebras L whose corresponding Lie algebra L/I is the algebra nn,1 with condition that the ideal I is a Fock nn,1-module, where I is the ideal generated by squares of elements from L.We also consider Leibniz algebras with corresponding Lie algebra nn,1 and such that the action I×nn,1I gives rise to a minimal faithful representation of nn,1. The classification up to isomorphism of such Leibniz algebras is given for the case of n=4.  相似文献   
49.
We study a family of stationary increment Gaussian processes, indexed by time. These processes are determined by certain measures σ (generalized spectral measures), and our focus here is on the case when the measure σ is a singular measure. We characterize the processes arising from σ when σ is in one of the classes of affine selfsimilar measures. Our analysis makes use of Kondratiev white noise spaces. With the use of a priori estimates and the Wick calculus, we extend and sharpen (see Theorem 7.1) earlier computations of Ito stochastic integration developed for the special case of stationary increment processes having absolutely continuous measures. We further obtain an associated Ito formula (see Theorem 8.1).  相似文献   
50.
The aim of this paper is to initiate a systematic study of the Orlicz Figà – Talamanca Herz algebras on locally compact groups. We also introduce and study invariant means on the dual of these algebras.  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