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   8441篇
  免费   445篇
  国内免费   513篇
化学   87篇
力学   551篇
综合类   60篇
数学   8194篇
物理学   507篇
  2024年   8篇
  2023年   77篇
  2022年   69篇
  2021年   88篇
  2020年   157篇
  2019年   178篇
  2018年   179篇
  2017年   179篇
  2016年   191篇
  2015年   167篇
  2014年   317篇
  2013年   765篇
  2012年   304篇
  2011年   405篇
  2010年   348篇
  2009年   531篇
  2008年   592篇
  2007年   564篇
  2006年   457篇
  2005年   415篇
  2004年   332篇
  2003年   332篇
  2002年   300篇
  2001年   273篇
  2000年   263篇
  1999年   226篇
  1998年   260篇
  1997年   216篇
  1996年   150篇
  1995年   105篇
  1994年   119篇
  1993年   86篇
  1992年   77篇
  1991年   50篇
  1990年   50篇
  1989年   43篇
  1988年   44篇
  1987年   46篇
  1986年   47篇
  1985年   53篇
  1984年   46篇
  1983年   25篇
  1982年   36篇
  1981年   33篇
  1980年   46篇
  1979年   42篇
  1978年   29篇
  1977年   27篇
  1976年   34篇
  1974年   7篇
排序方式: 共有9399条查询结果,搜索用时 46 毫秒
71.
72.
Asymptotic methods for contact problems are expounded. Some typical integral equations are considered  相似文献   
73.
In this paper, the authors study the inclusion relations between Dirichlet type spaces DT and α-Bloch spacesβα by means of higher radial derivative. The strictness and the best possibility of the inclusion relations are shown with constructive methods.Furthermore, they sharpen one of the results when T = n, which proves that a conjecture in [7] is true.  相似文献   
74.
Calleja et al. [Calleja, P., Borm, P., Hendrickx, R., 2005. Multi-issue allocation situations. European Journal of Operational Research 164, 730–747] introduced multi-issue allocation situations with awards. In this paper, we extend the classical model of cooperative games with transferable utility to the cooperative games with transferable utility and awards. We define a run-to-the-bank rule for cooperative games with transferable utility and awards and characterise it in terms of a property of balanced contributions. We apply our main result to bankruptcy problems and multi-issue allocation situations with awards.  相似文献   
75.
利用极小极大方法获得了一类Dirichlet问题多重解的存在性结果.  相似文献   
76.
关于《一类奇异边值问题的正解》的注记   总被引:3,自引:0,他引:3  
柴国庆 《数学学报》2003,46(6):1087-109
文[4]通过构造反例断言文[1]中定理的必要性证明有误,本文首先指出文[4] 的这个断言不正确,然后对文[4]中定理2.1作了本质性的改进.  相似文献   
77.
An exponentially fitted special second-order finite difference method is presented for solving singularly perturbed two-point boundary value problems with the boundary layer at one end (left or right) point. A fitting factor is introduced in a tri-diagonal finite difference scheme and is obtained from the theory of singular perturbations. Thomas Algorithm is used to solve the system and its stability is investigated. To demonstrate the applicability of the method, we have solved several linear and non-linear problems. From the results, it is observed that the present method approximates the exact solution very well.  相似文献   
78.
The nonlocal boundary value problems for anisotropic partial differential-operator equations with a dependent coefficients are studied. The principal parts of the appropriate generated differential operators are nonself-adjoint. Several conditions for the maximal regularity and the fredholmness in Banach-valued Lp-spaces of these problems are given. These results permit us to establish that the inverse of corresponding differential operators belongs to Schatten q-class. Some spectral properties of the operators are investigated. In applications, the nonlocal BVP's for quasielliptic partial differential equations and for systems of quasielliptic equations on cylindrical domain are studied.  相似文献   
79.
Summary. The convergence rate of Krylov subspace methods for the solution of nonsymmetric systems of linear equations, such as GMRES or FOM, is studied. Bounds on the convergence rate are presented which are based on the smallest real part of the field of values of the coefficient matrix and of its inverse. Estimates for these quantities are available during the iteration from the underlying Arnoldi process. It is shown how these bounds can be used to study the convergence properties, in particular, the dependence on the mesh-size and on the size of the skew-symmetric part, for preconditioners for finite element discretizations of nonsymmetric elliptic boundary value problems. This is illustrated for the hierarchical basis and multilevel preconditioners which constitute popular preconditioning strategies for such problems. Received May 3, 1996  相似文献   
80.
This study provides a stability theory for the nonlinear least-squares formulation of estimating the diffusion coefficient in a two-point boundary-value problem from an error-corrupted observation of the state variable. It is based on analysing the projection of the observation on the nonconvex attainable set.This research was started while G. Chavent visited the Technical University of Graz. Support through the Steiermaerkische Landesregierung is gratefully acknowledged.  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