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   129篇
  免费   14篇
  国内免费   5篇
化学   2篇
力学   9篇
综合类   2篇
数学   52篇
物理学   83篇
  2025年   1篇
  2024年   2篇
  2023年   4篇
  2022年   3篇
  2021年   5篇
  2020年   4篇
  2019年   3篇
  2018年   4篇
  2017年   2篇
  2016年   5篇
  2015年   3篇
  2014年   1篇
  2013年   5篇
  2012年   2篇
  2011年   3篇
  2010年   8篇
  2009年   4篇
  2008年   13篇
  2007年   11篇
  2006年   8篇
  2005年   5篇
  2004年   11篇
  2003年   9篇
  2002年   4篇
  2001年   2篇
  2000年   4篇
  1999年   7篇
  1998年   3篇
  1997年   3篇
  1996年   5篇
  1990年   1篇
  1986年   1篇
  1979年   1篇
  1976年   1篇
排序方式: 共有148条查询结果,搜索用时 0 毫秒
51.
共变完全多正线性映射的共变投射表示   总被引:1,自引:0,他引:1  
许天周 《数学学报》2008,51(2):357-364
研究了C*-代数中的共变完全多正线性映射,证明了共变完全多正线性映射可以诱导Hilbert C*-模上的共变投射表示,并且给出了共变完全多正线性映射的KS- GNS(Kasparov,Stinespring,Gel’fand,Naimark,Segal)构造.  相似文献   
52.
    
Hawking radiation from cosmological horizon and event horizon of the Reissner-Nordström de Sitter black hole with a global monopole is studied via a new method that was propounded by Robinson and Wilzek and elaborated by Banerjee and Kulkarni. The results show that the gauge current and energy-momentum tensor fluxes, which required keeping gauge covariance and general coordinate invariance at the quantum level in the effective field theory, are exactly equivalent to those of Hawking radiation from the event horizon and the cosmological horizon,respectively.  相似文献   
53.
介绍了两个近期基于协变手征微扰理论构建领头阶核子-核子和超子-核子相互作用的工作。理论中未知的低能常数通过拟合核子-核子和超子-核子散射实验数据确定。分析发现,在对散射数据的描述上,领头阶相对论手征力可以媲美次领头阶非相对论手征核力。研究表明,构建相对论手征重子-重子相互作用技术上是可行的。得到的相互作用不仅可以为相对论核结构及反应研究提供重要的理论输入,而且可以进一步加深对低能强相互作用的认识。In this paper, we report on two recent studies of relativistic nucleon-nucleon and hyperonnucleon interactions in covariant chiral perturbation theory, where they are constructed up to leading order. The relevant unknown low energy constants are fixed by fitting to the nucleon-nucleon and hyperon-nucleon scattering data. It is shown that these interactions can describe the scattering data with a quality similar to their next-to-leading order non-relativistic counterparts. These studies show that it is technically feasible to construct relativist baryon-baryon interactions, and in addition, after further refinements, these interactions may provide important inputs to ab initio relativistic nuclear structure and reaction studies and help improve our understanding of low energy strong interactions.  相似文献   
54.
本文通过对J/ψ辐射衰变到K+K-πO和终态中iota能区的振幅分析,发现iota峰下有一个0-+共振态(M=1467±3MeV,=89±6MeV)和两个1++共振态(M=1435±3MeV,=59±5MeV;M=1497±2MeV,=44±7MeV),分别对应于η(1440),f1(1420)和f1(1510).  相似文献   
55.
A class of objects—that are best described as being actions ofgroup-like objects of von Neumann algebras—is axiomatised and it is shown that there exists a bijective correspondence between isomorphism classes of suchcovariant systems and isomorphism classes of pairs of II1 factors (M, N) satisfyingN⊂M, [M:N]<∞ andMN′=C.  相似文献   
56.
The canonical covariant formalism (CCF) of the topological five-dimensional Chern–Simons gravity is constructed. Because this gravity model naturally contains a Gauss–Bonnet term, the extended CCF valid for higher curvature gravity must be used. In this framework, the primary constraint and the total Hamiltonian are found. By using the equations of the CCF, it is shown that the bosonic five-form which defines the total Hamiltonian is a first-class dynamical quantity strongly conserved. In this context the equations of motion are also analyzed. To determine the effective interactions of the model, the toroidal dimensional reduction of the five-dimensional Chern–Simons gravity is carried out. Finally the first-order CCF and the usual canonical vierbein formalism (CVF) are related and the Hamiltonian as generator of time evolution is constructed in terms of the first-class constraints of the coupled system.  相似文献   
57.
蔡志东 《物理通报》2021,(4):147-150
介绍了傅里叶级数和傅里叶变换的基本思想,从哲学、物理学和数学的角度阐述了其深刻涵义和伟大之处.指出了傅里叶的思想和牛顿-莱布尼茨的思想的不同之处.导出了四维协变的傅里叶变换公式.简要介绍了傅里叶级数和变换在物理学中的应用.  相似文献   
58.
Let U(G) be a maximal unipotent subgroup of one of the classical groups G=GL(V), O(V), Sp(V). Let W be a direct sum of copies of V and its dual V*. For the natural action U(G) : W, we describe a minimal system of homogeneous generators for the algebra of U(G)-invariant regular functions on W. For G=O(V), Sp(V), this result is connected with a construction for the irreducible representations of G due to H. Weyl.  相似文献   
59.
在国家基金项目的支持下,本研究基于电子论和洛伦兹磁力否定法拉第定律和相对论电磁学,暨揭示广义洛伦兹磁力的科学研究之三:旋度电场和协变场不存在.文[1]介绍了广义洛伦兹磁力的定义及其及其证明,并论证指出广义洛伦兹磁力是真谛;文[2-3]介绍了法拉第电动势ε是虚构的,虚构的法拉第定律存在几个关键问题.正因如此,所以法拉第定律不具有普适性.感应电流的产生与磁通量变化率无关.  相似文献   
60.
We derive a new formula for the supersymmetric Schur polynomial s (x/y). The origin of this formula goes back to representation theory of the Lie superalgebra gl(m/n). In particular, we show how a character formula due to Kac and Wakimoto can be applied to covariant representations, leading to a new expression for s (x/y). This new expression gives rise to a determinantal formula for s (x/y). In particular, the denominator identity for gl(m/n) corresponds to a determinantal identity combining Cauchy's double alternant with Vandermonde's determinant. We provide a second and independent proof of the new determinantal formula by showing that it satisfies the four characteristic properties of supersymmetric Schur polynomials. A third and more direct proof ties up our formula with that of Sergeev-Pragacz.  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