全文获取类型
收费全文 | 891篇 |
免费 | 46篇 |
国内免费 | 18篇 |
专业分类
化学 | 77篇 |
力学 | 36篇 |
综合类 | 1篇 |
数学 | 627篇 |
物理学 | 214篇 |
出版年
2024年 | 1篇 |
2023年 | 12篇 |
2022年 | 11篇 |
2021年 | 14篇 |
2020年 | 13篇 |
2019年 | 7篇 |
2018年 | 13篇 |
2017年 | 14篇 |
2016年 | 33篇 |
2015年 | 21篇 |
2014年 | 36篇 |
2013年 | 82篇 |
2012年 | 37篇 |
2011年 | 79篇 |
2010年 | 54篇 |
2009年 | 82篇 |
2008年 | 67篇 |
2007年 | 58篇 |
2006年 | 66篇 |
2005年 | 27篇 |
2004年 | 30篇 |
2003年 | 17篇 |
2002年 | 29篇 |
2001年 | 18篇 |
2000年 | 16篇 |
1999年 | 18篇 |
1998年 | 12篇 |
1997年 | 12篇 |
1996年 | 12篇 |
1995年 | 7篇 |
1994年 | 14篇 |
1993年 | 8篇 |
1992年 | 5篇 |
1991年 | 8篇 |
1990年 | 4篇 |
1989年 | 1篇 |
1988年 | 3篇 |
1987年 | 2篇 |
1985年 | 4篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1979年 | 4篇 |
1978年 | 1篇 |
1971年 | 1篇 |
排序方式: 共有955条查询结果,搜索用时 15 毫秒
151.
In this paper, we consider second order elliptic problems with rapidly oscillating coefficients. On basis of [O.A. Oleinik, A.S. Shamaev, G.A. Yosifian, Mathematical Problems in Elasticity and Homogenization, North-Holland, Amsterdam, 1992; Wen-ming He, Jun-zhi Cui, A pointwise estimate on the 1-order approximation of , IMA J. Appl. Math. 70 (2005) 241-269] we propose a new approximate method to solve these problems. Of course, we present its error estimate. 相似文献
152.
We present an elementary theory of optimal interleaving schemes for correcting cluster errors in two-dimensional digital data. It is assumed that each data page contains a fixed number of, say n, codewords with each codeword consisting of m code symbols and capable of correcting a single random error (or erasure). The goal is to interleave the codewords in the m×n array such that different symbols from each codeword are separated as much as possible, and consequently, an arbitrary error burst with size up to t can be corrected for the largest possible value of t. We show that, for any given m, n, the maximum possible interleaving distance, or equivalently, the largest size of correctable error bursts in an m×n array, is given by if n?⌈m2/2⌉, and t=m+⌊(n-⌈m2/2⌉)/m⌋ if n?⌈m2/2⌉. Furthermore, we develop a simple cyclic shifting algorithm that can provide a systematic construction of an m×n optimal interleaving array for arbitrary m and n. This extends important earlier work on the complementary problem of constructing interleaving arrays that, given the burst size t, minimize the interleaving degree, that is, the number of different codewords in a 2-D (or 3-D) array such that any error burst with given size t can be corrected. Our interleaving scheme thus provides the maximum burst error correcting power without requiring prior knowledge of the size or shape of an error burst. 相似文献
153.
We utilize the classical hypercircle method and the lowest-order Raviart–Thomas H(div) element to obtain a posteriori error estimates of the P1 finite element solutions for 2D Poisson's equation. A few other estimation methods are also discussed for comparison. We give some theoretical and numerical results to see the effectiveness of the methods. 相似文献
154.
Qi Duan Huanling Zhang Yunfeng Zhang E.H. Twizell 《Journal of Computational and Applied Mathematics》2007
This paper deals with the approximation properties of a kind of rational spline with linear denominator when the function being interpolated is C3 in an interpolating interval. Error estimate expressions of interpolating functions are derived, convergence is established, the optimal error coefficient, ci, is proved to be symmetric about the parameters of the rational interpolation and it is bounded. Finally, the precise jump measurements of the second derivatives of the interpolating function at the knots are given. 相似文献
155.
Wei-zhu Bao 《计算数学(英文版)》1998,16(3):239-256
1.IntroductionManyproblemsarisinginfluidmechanicsaregiveninanunboundeddomain,suchasfluidflowaroundobstacles.Whencomputingthenumericalsolutionsoftheseproblems,oneoftenintroducesartificialboundariesandsetsupaxtificialboundaryconditionsonthem.Thentheoriginal… 相似文献
156.
157.
GENERALIZED DIFFERENCE METHODS ON ARBITRARY QUADRILATERAL NETWORKS 总被引:14,自引:0,他引:14
1.IntroductionConsidertheboundaryvalueproblemofthePoissonequationwherefiisaconvexpolygonregon;r~OfftheboundaryofOandf(x,y)aknownfunctiononfi.Thegeneralizeddifferencemethodsonquadrilateralnetworksforellipticequationsareproposedin[11],'wheretheconverge... 相似文献
158.
In this paper, the error estimation and adaptive strategy developed for the linear elastodynamic problem under transient dynamic loading based on the Z–Z criterion is utilized for 2D and plate bending problems. An automatic mesh generator based on “growth meshing” is utilized effectively for adaptive mesh refinement. Optimal meshes are obtained iteratively corresponding to the prescribed domain discretization error limit and for a chosen number of basis modes satisfying modal truncation errors. Numerous examples show the effectiveness of the integrated approach in achieving the target accuracy in finite element transient dynamic analysis. 相似文献
159.
Average Width and Optimal Recovery of Some Anisotropic Classes of Smooth Functions Defined on the Euclidean Space R~d 总被引:1,自引:0,他引:1
§ 1.Introduction and Main Results In[1 ] ,[2 ] ,the authors studied some problems of optimal recovery of functions de-fined on a cube,for a class of functions with partial derivatives of a fixed order havingmoduli of continuity not exceeding a given modules of continuity,and for the unit ballsSHαp in the spaces Hαp satisfying the mixed Holder conditionα,respectively.They ob-tained some weak asymptotic results. In[3 ] ,[4 ] and[5] ,Magarill-Il' yaev,Liu and Sun studied some proble… 相似文献
160.