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   1333篇
  免费   50篇
  国内免费   180篇
化学   5篇
力学   29篇
综合类   11篇
数学   1063篇
物理学   31篇
综合类   424篇
  2024年   2篇
  2023年   3篇
  2022年   6篇
  2021年   7篇
  2020年   19篇
  2019年   27篇
  2018年   27篇
  2017年   15篇
  2016年   33篇
  2015年   28篇
  2014年   64篇
  2013年   70篇
  2012年   57篇
  2011年   46篇
  2010年   68篇
  2009年   79篇
  2008年   77篇
  2007年   115篇
  2006年   117篇
  2005年   63篇
  2004年   65篇
  2003年   60篇
  2002年   58篇
  2001年   33篇
  2000年   55篇
  1999年   47篇
  1998年   53篇
  1997年   41篇
  1996年   41篇
  1995年   19篇
  1994年   21篇
  1993年   22篇
  1992年   25篇
  1991年   12篇
  1990年   10篇
  1989年   12篇
  1988年   7篇
  1987年   9篇
  1986年   2篇
  1985年   7篇
  1984年   7篇
  1983年   2篇
  1982年   7篇
  1981年   8篇
  1980年   5篇
  1979年   3篇
  1978年   4篇
  1977年   3篇
  1976年   1篇
  1936年   1篇
排序方式: 共有1563条查询结果,搜索用时 531 毫秒
81.
In this paper we shall show that the boundary of the hyperbolic building considered by M. Bourdon admits Poincaré type inequalities. Then by using Heinonen-Koskela's work, we shall prove Loewner capacity estimates for some families of curves of and the fact that every quasiconformal homeomorphism is quasisymmetric. Therefore by these results, the answer to questions 19 and 20 of Heinonen and Semmes (Thirty-three YES or NO questions about mappings, measures and metrics, Conform Geom. Dyn. 1 (1997), 1-12) is NO.

  相似文献   

82.
By applying the heuristic principle in several complex variables obtained by Aladro and Krantz, we shall prove some normality criteria for families of holomorphic mappings of several complex variables into , the complex N-dimensional projective space, related to Green's and Nochka's Picard type theorems. The equivalence of normality to being uniformly Montel at a point will be obtained. Some examples will be given to complement our theory in this paper.

  相似文献   

83.
We present an algorithm for variational inequalities VI( , Y) that uses a primal-dual version of the Analytic Center Cutting Plane Method. The point-to-set mapping is assumed to be monotone, or pseudomonotone. Each computation of a new analytic center requires at most four Newton iterations, in theory, and in practice one or sometimes two. Linear equalities that may be included in the definition of the set Y are taken explicitly into account.We report numerical experiments on several well—known variational inequality problems as well as on one where the functional results from the solution of large subproblems. The method is robust and competitive with algorithms which use the same information as this one.  相似文献   
84.
本文讨论了Fuzzy度量空间中映像对和映像族的公共不动点问题,所获定理推广了Kaleva.O Seikkala. S和郑叔的有关结果。  相似文献   
85.
For twice smooth functions, the symmetry of the matrix of second partial derivatives is automatic and can be seen as the symmetry of the Jacobian matrix of the gradient mapping. For nonsmooth functions, possibly even extended-real-valued, the gradient mapping can be replaced by a subgradient mapping, and generalized second derivative objects can then be introduced through graphical differentiation of this mapping, but the question of what analog of symmetry might persist has remained open. An answer is provided here in terms of a derivative-coderivative inclusion.  相似文献   
86.
87.
We show that a discrete, quasiconformal group preserving n has the property that its exponent of convergence and the Hausdorff dimension of its limit set detect the existence of a non-empty regular set on the sphere at infinity to n . This generalizes a result due separately to Sullivan and Tukia, in which it is further assumed that the group act isometrically on n , i.e. is a Kleinian group. From this generalization we are able to extract geometric information about infinite-index subgroups within certain of these groups.  相似文献   
88.
On the Existence of Solutions of Quasivariational Inclusion Problems   总被引:3,自引:0,他引:3  
Quasivariational inclusion problems are formulated and sufficient conditions on the existence of solutions are shown. As special cases, we obtain several results on the existence of solutions of general vector ideal, proper, Pareto, weak quasioptimization problems, quasivariational inequalities, and vector quasiequilibrium problems. Further, we prove theorems on the existence for solutions of systems of these inclusions. As a corollary, we obtain an ideal minimax theorem concerning vector functions.  相似文献   
89.
Let be a sequence of locally quasiconformal harmonic maps on the unit disk with respect to the Poincaré metric. Suppose that the energy densities of are uniformly bounded from below by a positive constant and locally uniformly bounded from above. Then there is a subsequence of that locally uniformly converges on , and the limit function is either a locally quasiconformal harmonic map of the Poincaré disk or a constant. Especially, if the limit function is not a constant, the subsequence can be chosen to satisfy some stronger conditions. As an application, it is proved that every point of the space , a subspace of the universal Teichmüller space, can be represented by a quasiconformal harmonic map that is an asymptotic hyperbolic isometry.

  相似文献   

90.
Let be a contractive gauge function in the sense that φ is continuous, φ(s)<s for s>0, and if f:M→M satisfies d(f(x),f(y))?φ(d(x,y)) for all x,y in a complete metric space (M,d), then f always has a unique fixed point. It is proved that if T:M→M satisfies
  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