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   1810篇
  免费   185篇
  国内免费   126篇
化学   24篇
晶体学   1篇
力学   224篇
综合类   42篇
数学   1593篇
物理学   237篇
  2025年   10篇
  2024年   24篇
  2023年   26篇
  2022年   24篇
  2021年   31篇
  2020年   43篇
  2019年   39篇
  2018年   39篇
  2017年   48篇
  2016年   52篇
  2015年   47篇
  2014年   87篇
  2013年   98篇
  2012年   40篇
  2011年   64篇
  2010年   71篇
  2009年   95篇
  2008年   127篇
  2007年   134篇
  2006年   117篇
  2005年   117篇
  2004年   89篇
  2003年   102篇
  2002年   84篇
  2001年   73篇
  2000年   77篇
  1999年   58篇
  1998年   71篇
  1997年   47篇
  1996年   27篇
  1995年   22篇
  1994年   20篇
  1993年   14篇
  1992年   14篇
  1991年   17篇
  1990年   13篇
  1989年   12篇
  1988年   4篇
  1987年   7篇
  1986年   2篇
  1985年   9篇
  1984年   3篇
  1983年   1篇
  1982年   5篇
  1981年   5篇
  1980年   8篇
  1977年   1篇
  1976年   1篇
  1974年   1篇
  1971年   1篇
排序方式: 共有2121条查询结果,搜索用时 0 毫秒
51.
K. D. Kirchberg has given a minoration of the absolute value of the eigenvalues of the Dirac operator for a compact Kähler spin manifold (W,g) with positive scalar curvature and has introduced, in this context, the notion of Kähler twistor-spinor. We prove here that if dimC W = p 4 is even, in the limiting case, (W, g) is the Kähler product of an odd-dimensional limiting case compact Kähler spin manifold of complex dimension (p-1), by a flat Kähler manifold which is a compact quotient of C.  相似文献   
52.
In the paper, we consider applications of strictly pseudoconvex domains to the problems of algebraicity and rationality. We give a new proof of the Kodaira theorem on the algebraicity of a surface and we also prove a multidimensional version of this theorem. Theorems analogous to the Hodge index theorem and the Lefschetz theorem about (1, 1)-classes are obtained for strictly pseudoconvex domains. Conjectures on the geometry of strictly pseudoconvex domains on algebraic surfaces are formulated. Translated fromMatematicheskie Zametki, Vol. 60, No. 3, pp. 414–422, September, 1996. This research was supported by the Russian Foundation for Basic Research under grant No. 93-01-00225 and by the International Science Foundation under grant No. 508.  相似文献   
53.
We use the contact Yamabe flow to find solutions of the contact Yamabe problem on K-contact manifolds.  相似文献   
54.
55.
    
In this study, the dynamics of a reaction–diffusion equation on a bounded interval at the first dynamic transition point is investigated. The main difference of this study from the existing ones in the dynamic transition literature is that in this work, no specific form of the nonlinear operator is assumed except that it is an analytic function of u$u$ and ux$u_x$. The linear operator is also assumed to be a general operator with sinusoidal eigenvectors. Moreover, we assume that there is a first transition as a real simple eigenvalue changes sign. With this general framework, we make a rigorous analysis of the dependence of the first transition dynamics on the coefficients of the Taylor expansion of the nonlinear operator. The main tool we use in this study is the center manifold reduction combined with the classification of the dynamic transition theory. This study is a generalization of a recent work where the nonlinear operator contains only low-order (quadratic and cubic) nonlinearities. The current generalization requires certain technical difficulties such as the validity of the genericity conditions on the Taylor coefficients of the nonlinear operator and a bootstrapping argument using these genericity conditions. The results of this work can be generalized in various directions, which are discussed in the conclusions section.  相似文献   
56.
57.
58.
59.
    
Geometry of affine immersions is the study of hypersurfaces that are invariant under affine transformations. As with the hypersurface theory on the Euclidean space, an affine immersion can induce a torsion-free affine connection and a (pseudo)-Riemannian metric on the hypersurface. Moreover, an affine immersion can induce a statistical manifold, which plays a central role in information geometry. Recently, a statistical manifold with a complex structure is actively studied since it connects information geometry and Kähler geometry. However, a holomorphic complex affine immersion cannot induce such a statistical manifold with a Kähler structure. In this paper, we introduce complex affine distributions, which are non-integrable generalizations of complex affine immersions. We then present the fundamental theorem for a complex affine distribution, and show that a complex affine distribution can induce a statistical manifold with a Kähler structure.  相似文献   
60.
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