全文获取类型
收费全文 | 15162篇 |
免费 | 1239篇 |
国内免费 | 711篇 |
专业分类
化学 | 723篇 |
晶体学 | 7篇 |
力学 | 941篇 |
综合类 | 188篇 |
数学 | 12813篇 |
物理学 | 2440篇 |
出版年
2024年 | 17篇 |
2023年 | 124篇 |
2022年 | 129篇 |
2021年 | 205篇 |
2020年 | 279篇 |
2019年 | 251篇 |
2018年 | 280篇 |
2017年 | 402篇 |
2016年 | 395篇 |
2015年 | 259篇 |
2014年 | 472篇 |
2013年 | 920篇 |
2012年 | 675篇 |
2011年 | 548篇 |
2010年 | 427篇 |
2009年 | 1204篇 |
2008年 | 1152篇 |
2007年 | 1028篇 |
2006年 | 742篇 |
2005年 | 657篇 |
2004年 | 548篇 |
2003年 | 632篇 |
2002年 | 820篇 |
2001年 | 864篇 |
2000年 | 774篇 |
1999年 | 840篇 |
1998年 | 644篇 |
1997年 | 486篇 |
1996年 | 275篇 |
1995年 | 253篇 |
1994年 | 185篇 |
1993年 | 90篇 |
1992年 | 95篇 |
1991年 | 60篇 |
1990年 | 45篇 |
1989年 | 25篇 |
1988年 | 36篇 |
1987年 | 37篇 |
1986年 | 27篇 |
1985年 | 39篇 |
1984年 | 31篇 |
1983年 | 14篇 |
1982年 | 17篇 |
1981年 | 16篇 |
1980年 | 27篇 |
1979年 | 21篇 |
1978年 | 7篇 |
1977年 | 13篇 |
1976年 | 6篇 |
1971年 | 3篇 |
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
1.
2.
In this article, we construct and analyze a residual-based a posteriori error estimator for a quadratic finite volume method (FVM) for solving nonlinear elliptic partial differential equations with homogeneous Dirichlet boundary conditions. We shall prove that the a posteriori error estimator yields the global upper and local lower bounds for the norm error of the FVM. So that the a posteriori error estimator is equivalent to the true error in a certain sense. Numerical experiments are performed to illustrate the theoretical results. 相似文献
3.
4.
Mourad Kainane Mezadek Mohamed Kainane Mezadek Michael Reissig 《Mathematical Methods in the Applied Sciences》2020,43(6):3117-3147
In this paper, we study the global (in time) existence of small data solutions to the Cauchy problem for the semilinear wave equation with friction, viscoelastic damping, and a power nonlinearity. We are interested in the connection between regularity assumptions for the data and the admissible range of exponents p in the power nonlinearity. 相似文献
5.
非线性互补问题的一种全局收敛的显式光滑Newton方法 总被引:2,自引:0,他引:2
本针对Po函数非线性互补问题,给出了一种显式光滑Newton方法,该方法将光滑参数μ进行显式迭代而不依赖于Newton方向的搜索过程,并在适当的假设条件下,证明了算法的全局收敛性。 相似文献
6.
We prove that to most of the known hypercyclic operators A on separable Banach spaces there exist compact (compact convex, compact connected) subsets K of E such that each compact (compact convex, compact connected) subset of E can be approximated with respect to Hausdorff's distance by for suitable .
Received July 8, 1997, in final form October 17, 1997 相似文献
7.
8.
Peter Imkeller 《Probability Theory and Related Fields》1996,106(1):105-135
Summary. The analytic treatment of problems related to the asymptotic behaviour of random dynamical systems generated by stochastic
differential equations suffers from the presence of non-adapted random invariant measures. Semimartingale theory becomes accessible
if the underlying Wiener filtration is enlarged by the information carried by the orthogonal projectors on the Oseledets spaces
of the (linearized) system.
We study the corresponding problem of preservation of the semimartingale property and the validity of a priori inequalities
between the norms of stochastic integrals in the enlarged filtration and norms of their quadratic variations in case the random
element F enlarging the filtration is real valued and possesses an absolutely continuous law. Applying the tools of Malliavin’s calculus,
we give smoothness conditions on F under which the semimartingale property is preserved and a priori martingale inequalities are valid.
Received: 12 April 1995 / In revised form: 7 March 1996 相似文献
9.
We discuss an error estimation procedure for the global error of collocation schemes applied to solve singular boundary value problems with a singularity of the first kind. This a posteriori estimate of the global error was proposed by Stetter in 1978 and is based on the idea of Defect Correction, originally due to Zadunaisky. Here, we present a new, carefully designed modification of this error estimate which not only results in less computational work but also appears to perform satisfactorily for singular problems. We give a full analytical justification for the asymptotical correctness of the error estimate when it is applied to a general nonlinear regular problem. For the singular case, we are presently only able to provide computational evidence for the full convergence order, the related analysis is still work in progress. This global estimate is the basis for a grid selection routine in which the grid is modified with the aim to equidistribute the global error. This procedure yields meshes suitable for an efficient numerical solution. Most importantly, we observe that the grid is refined in a way reflecting only the behavior of the solution and remains unaffected by the unsmooth direction field close to the singular point. 相似文献
10.
Masaaki Sugihara 《Numerische Mathematik》1997,75(3):379-395
Summary. In the light of the functional analysis theory we establish the optimality of the double exponential formula. The argument
consists of the following three ingredients: (1) introduction of a number of spaces of functions analytic in a strip region
about the real axis, each space being characterized by the decay rate of their elements (functions) in the neighborhood of
the infinity; (2) proof of the (near-) optimality of the trapezoidal formula in each space introduced in (1) by showing the
(near-) equality between an upper estimate for the error norm of the trapezoidal formula and a lower estimate for the minimum
error norm of quadratures; (3) nonexistence theorem for the spaces, the characterizing decay rate of which is more rapid than
the double exponential.
Received September 15, 1995 / Accepted December 14, 1995 相似文献