全文获取类型
收费全文 | 1245篇 |
免费 | 69篇 |
国内免费 | 91篇 |
专业分类
化学 | 62篇 |
力学 | 275篇 |
综合类 | 6篇 |
数学 | 794篇 |
物理学 | 268篇 |
出版年
2024年 | 4篇 |
2023年 | 14篇 |
2022年 | 7篇 |
2021年 | 14篇 |
2020年 | 19篇 |
2019年 | 36篇 |
2018年 | 27篇 |
2017年 | 27篇 |
2016年 | 28篇 |
2015年 | 36篇 |
2014年 | 60篇 |
2013年 | 112篇 |
2012年 | 39篇 |
2011年 | 100篇 |
2010年 | 87篇 |
2009年 | 93篇 |
2008年 | 84篇 |
2007年 | 65篇 |
2006年 | 67篇 |
2005年 | 67篇 |
2004年 | 48篇 |
2003年 | 61篇 |
2002年 | 48篇 |
2001年 | 35篇 |
2000年 | 33篇 |
1999年 | 35篇 |
1998年 | 37篇 |
1997年 | 27篇 |
1996年 | 22篇 |
1995年 | 12篇 |
1994年 | 12篇 |
1993年 | 5篇 |
1992年 | 6篇 |
1991年 | 6篇 |
1990年 | 4篇 |
1989年 | 2篇 |
1988年 | 6篇 |
1986年 | 1篇 |
1985年 | 7篇 |
1984年 | 2篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1980年 | 4篇 |
1979年 | 2篇 |
1978年 | 1篇 |
1977年 | 1篇 |
排序方式: 共有1405条查询结果,搜索用时 15 毫秒
131.
132.
We propose a method for generating finite-difference approximations of transparent boundary conditions (TBCs) with the fourth and sixth order in space. It is based on the wave equation solution continuation extra two or three layers of grid points outside the computational domain to use them in central-difference operators on approaching the boundary. We present the theoretical background of the method, give estimates of computational resources, and discuss accuracy and stability results of numerical tests in 1D and 2D cases. 相似文献
133.
Bo Wang Guang-an Zou Peng ZhaoQiang Wang 《Applied mathematics and computation》2011,217(12):5227-5235
In this paper, finite volume method is used to solve a one-dimensional parabolic inverse problem with source term and Neumann boundary conditions for the first time. Some advantages of this approach are developing difference schemes and maintaining certain properties of the physics of the problems, especially for the treatment of the source term and the unknown boundary conditions. Numerical results show that our method is more effective. 相似文献
134.
This paper deals with a high-order accurate implicit finite-difference approach to the pricing of barrier options. In this way various types of barrier options are priced, including barrier options paying rebates, and options on dividend-paying-stocks. Moreover, the barriers may be monitored either continuously or discretely. In addition to the high-order accuracy of the scheme, and the stretching effect of the coordinate transformation, the main feature of this approach lies on a probability-based optimal determination of boundary conditions. This leads to much faster and accurate results when compared with similar pricing approaches. The strength of the present scheme is particularly demonstrated in the valuation of discretely monitored barrier options where it yields values closest to those obtained from the only semi-analytical valuation methods available. The scheme is also applied to the analysis of Greeks data such as Delta and Gamma. 相似文献
135.
Wei LiuQimin Zhang 《Applied mathematics and computation》2011,218(8):3973-3980
In general, most of stochastic age-structured system of three species do not have explicit solutions, thus numerical approximation schemes are invaluable tools for exploring their properties. The aim of this paper is to investigate the convergence of numerical approximation solution to the true solution for stochastic age-structured system of three species. 相似文献
136.
The spectral analysis of an efficient step-by-step direct integration algorithm for the structural dynamic equation is presented. The proposed algorithm is formulated in terms of two Hermitian finite difference operators of fifth-order local truncation error and it is unconditionally stable with no numerical damping presenting a fourth-order truncation error for period dispersion (global error). In addition, although it is in competition with higher-order algorithms presented in the literature, the computational effort is similar to that of the classical second-order Newmark’s method. The numerical application for nonlinear structural dynamic problems is also considered. 相似文献
137.
Murat Sari Gürhan Gürarslan Asuman Zeytinoğlu 《Numerical Methods for Partial Differential Equations》2011,27(5):1313-1326
In this article, up to tenth‐order finite difference schemes are proposed to solve the generalized Burgers–Huxley equation. The schemes based on high‐order differences are presented using Taylor series expansion. To establish the numerical solutions of the corresponding equation, the high‐order schemes in space and a fourth‐order Runge‐Kutta scheme in time have been combined. Numerical experiments have been conducted to demonstrate the high‐order accuracy of the current algorithms with relatively minimal computational effort. The results showed that use of the present approaches in the simulation is very applicable for the solution of the generalized Burgers–Huxley equation. The current results are also seen to be more accurate than some results given in the literature. The proposed algorithms are seen to be very good alternatives to existing approaches for such physical applications. © 2010 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 27: 1313‐1326, 2011 相似文献
138.
Liping Liu Dominic P. Clemence Ronald E. Mickens 《Numerical Methods for Partial Differential Equations》2011,27(4):767-785
This study focuses on a contaminant transport model with Langmuir sorption under nonequilibrium conditions. The numerical instabilities of the standard finite difference schemes including the upwind method are investigated. By using the nonstandard finite difference method, a better finite difference model is constructed. The numerical simulation on a specific system configuration proves the advantages of the new finite difference model. © 2009 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 27: 767–785, 2011 相似文献
139.
F. Bauer 《Journal of Complexity》2011,27(1):68-85
Regularization is typically based on the choice of some parametric family of nearby solutions, and the choice of this family is a task in itself. Then, a suitable parameter must be chosen in order to find an approximation of good quality. We focus on the second task. There exist deterministic and stochastic models for describing noise and solutions in inverse problems. We will establish a unified framework for treating different settings for the analysis of inverse problems, which allows us to prove the convergence and optimality of parameter choice schemes based on minimization in a generic way. We show that the well known quasi-optimality criterion falls in this class. Furthermore we present a new parameter choice method and prove its convergence by using this newly established tool. 相似文献
140.
Dongyang Shi Huaijun Yang 《Numerical Methods for Partial Differential Equations》2019,35(3):1206-1223
This article concerns with the superconvergence analysis of bilinear finite element method (FEM) for nonlinear Poisson–Nernst–Planck (PNP) equations. By employing high accuracy integral identities together with mean value technique, the superclose estimates in H1‐norm are derived for the semi‐discrete and the backward Euler fully‐discrete schemes, which improve the suboptimal error estimate in L2‐norm in the previous literature. Furthermore, the global superconvergence results in H1‐norm are obtained through interpolation postprocessing approach. Finally, a numerical example is provided to confirm the theoretical analysis. 相似文献