全文获取类型
收费全文 | 2638篇 |
免费 | 172篇 |
国内免费 | 238篇 |
专业分类
化学 | 175篇 |
晶体学 | 1篇 |
力学 | 340篇 |
综合类 | 77篇 |
数学 | 2121篇 |
物理学 | 334篇 |
出版年
2024年 | 2篇 |
2023年 | 26篇 |
2022年 | 27篇 |
2021年 | 35篇 |
2020年 | 52篇 |
2019年 | 67篇 |
2018年 | 53篇 |
2017年 | 78篇 |
2016年 | 63篇 |
2015年 | 58篇 |
2014年 | 128篇 |
2013年 | 149篇 |
2012年 | 97篇 |
2011年 | 176篇 |
2010年 | 146篇 |
2009年 | 173篇 |
2008年 | 165篇 |
2007年 | 173篇 |
2006年 | 156篇 |
2005年 | 164篇 |
2004年 | 116篇 |
2003年 | 118篇 |
2002年 | 109篇 |
2001年 | 108篇 |
2000年 | 96篇 |
1999年 | 81篇 |
1998年 | 60篇 |
1997年 | 72篇 |
1996年 | 64篇 |
1995年 | 49篇 |
1994年 | 43篇 |
1993年 | 33篇 |
1992年 | 17篇 |
1991年 | 11篇 |
1990年 | 17篇 |
1989年 | 6篇 |
1988年 | 7篇 |
1987年 | 6篇 |
1986年 | 10篇 |
1985年 | 5篇 |
1984年 | 14篇 |
1983年 | 4篇 |
1981年 | 1篇 |
1980年 | 4篇 |
1979年 | 2篇 |
1977年 | 1篇 |
1976年 | 2篇 |
1973年 | 1篇 |
1971年 | 1篇 |
1966年 | 1篇 |
排序方式: 共有3048条查询结果,搜索用时 15 毫秒
991.
韩国强 《高等学校计算数学学报(英文版)》1994,(2)
In this paper, we consider the following problem:The quadratic spline collocation, with uniform mesh and the mid-knot points are taken as the collocation points for this problem is considered. With some assumptions, we have proved that the solution of the quadratic spline collocation for the nonlinear problem can be written as a series expansions in integer powers of the mesh-size parameter. This gives us a construction method for using Richardson's extrapolation. When we have a set of approximate solution with different mesh-size parameter a solution with high accuracy can he obtained by Richardson's extrapolation. 相似文献
992.
In this paper we consider simple methods for the reconstruction of the Cauchy transform over a curve when an explicit parametrization of the latter is not provided. The methods consist of replacing the parametrization of the curve by piecewise polynomial interpolation followed by the use of Newton-Cotes type formulae for the integration. The order of convergence of the resulting quadrature is higher than would be expected on the basis of considerations involving just interpolation theory, provided that the Cauchy transform is evaluated at known nodes on the curve. These results allow the calculation of the Cauchy transform at other points with the same accuracy if this scheme is followed by an interpolatory formula of sufficiently high accuracy. 相似文献
993.
Jiangguo Liu Richard E. Ewing Guan Qin 《Numerical Methods for Partial Differential Equations》2006,22(4):994-1006
In this article, we utilize spline wavelets to establish an adaptive multilevel numerical scheme for time‐dependent convection‐dominated diffusion problems within the frameworks of Galerkin formulation and Eulerian‐Lagrangian localized adjoint methods (ELLAM). In particular, we shall use linear Chui‐Quak semi‐orthogonal wavelets, which have explicit expressions and compact supports. Therefore, both the diffusion term and boundary conditions in the convection‐diffusion problems can be readily handled. Strategies for efficiently implementing the scheme are discussed and numerical results are interpreted from the viewpoint of nonlinear approximation. © 2005 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2006 相似文献
994.
WU Haijun & CHEN Zhiming Institute of Computational Mathematics Chinese Academy of Sciences Beijing China. Department of Mathematics Nanjing University Nanjing China 《中国科学A辑(英文版)》2006,49(10):1405-1429
In this paper we prove the uniform convergence of the standard multigrid V-cycle algorithm with the Gauss-Seidel relaxation performed only on the new nodes and their "immediate" neighbors for discrete elliptic problems on the adaptively refined finite element meshes using the newest vertex bisection algorithm. The proof depends on sharp estimates on the relationship of local mesh sizes and a new stability estimate for the space decomposition based on the Scott-Zhang interpolation operator. Extensive numerical results are reported, which confirm the theoretical analysis. 相似文献
995.
D.S. Franzblau 《Graphs and Combinatorics》2002,18(2):259-270
In this paper, a class of cubic planar graphs is given that have Hamiltonian cycles that can be constructed in linear time.
A member of this class is called a layered cubic planar graph, and consists of a sequence of cycles C
0
,C
1
,…,C
n
such that each pair of successive cycles, C
i
, C
i+1
, is joined by a matching. The cycles can be pictured as concentric circles, and the edges of the matchings as radial line
segments between successive circles. The subgraph bounded by two successive cycles forms a layer; each face in layer i is incident to a fixed number k
i+1
of edges in the matching in layer i+1. The problem that initially motivated this work is that of identifying classes of convex cubic polyhedra that can be easily
edge three-colored.
Received: September 21, 1998 Final version received: July 21, 1999 相似文献
996.
997.
In this article, we apply the univariate multiquadric (MQ) quasi‐interpolation to solve the hyperbolic conservation laws. At first we construct the MQ quasi‐interpolation corresponding to periodic and inflow‐outflow boundary conditions respectively. Next we obtain the numerical schemes to solve the partial differential equations, by using the derivative of the quasi‐interpolation to approximate the spatial derivative of the differential equation and a low‐order explicit difference to approximate the temporal derivative of the differential equation. Then we verify our scheme for the one‐dimensional Burgers' equation (without viscosity). We can see that the numerical results are very close to the exact solution and the computational accuracy of the scheme is ??(τ), where τ is the temporal step. We can improve the accuracy by using the high‐order quasi‐interpolation. Moreover the methods can be generalized to the other equations. © 2005 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2006 相似文献
998.
A finite difference scheme based on the operator-splitting technique with cubic spline functions is derived for solving the two-dimensional Burgers equations in ‘inhomogeneous’ form. The scheme is of first-order accuracy in time and second-order accuracy in space direction and is unconditionally stable. The numerical results are obtained with severe/moderate gradients in the initial and boundary conditions and the steady state solutions are plotted for different values of the parameters. It is concluded that the resulting scheme works very well even in the case of very severe gradient in the solution. Also, the general nature of the scheme provides a wider application in the solution of non-linear problems. 相似文献
999.
1000.
在本文中,我们考虑了将Legendre多项式零点垂直映射到单位圆周时所得到的一组节点集上(0,1,3)插值的一致收敛性. 相似文献