全文获取类型
收费全文 | 369篇 |
免费 | 12篇 |
国内免费 | 23篇 |
专业分类
化学 | 2篇 |
力学 | 23篇 |
数学 | 357篇 |
物理学 | 22篇 |
出版年
2023年 | 3篇 |
2022年 | 2篇 |
2021年 | 2篇 |
2020年 | 9篇 |
2019年 | 7篇 |
2018年 | 6篇 |
2017年 | 10篇 |
2016年 | 5篇 |
2015年 | 9篇 |
2014年 | 10篇 |
2013年 | 24篇 |
2012年 | 10篇 |
2011年 | 11篇 |
2010年 | 19篇 |
2009年 | 22篇 |
2008年 | 20篇 |
2007年 | 21篇 |
2006年 | 28篇 |
2005年 | 14篇 |
2004年 | 17篇 |
2003年 | 8篇 |
2002年 | 19篇 |
2001年 | 29篇 |
2000年 | 17篇 |
1999年 | 29篇 |
1998年 | 23篇 |
1997年 | 20篇 |
1996年 | 8篇 |
1995年 | 2篇 |
排序方式: 共有404条查询结果,搜索用时 31 毫秒
91.
92.
In this paper, we discuss the multiscale analysis and numerical algorithms for the wave equations of second order with rapidly oscillating coefficients. The formal multiscale asymptotic expansions of the solutions for these problems in four specific cases are presented. Higher order corrector methods are constructed and associated explicit convergence rates are obtained in some cases. A multiscale numerical method and a symplectic geometric scheme are introduced. Finally, some numerical results and unsolved problems are presented, and these numerical results support strongly the convergence theorem of this paper. 相似文献
93.
A null-space primal-dual interior-point algorithm for nonlinear optimization with nice convergence properties 总被引:1,自引:0,他引:1
We present a null-space primal-dual interior-point algorithm for solving nonlinear optimization problems with general inequality
and equality constraints. The algorithm approximately solves a sequence of equality constrained barrier subproblems by computing
a range-space step and a null-space step in every iteration. The ℓ2 penalty function is taken as the merit function. Under very mild conditions on range-space steps and approximate Hessians,
without assuming any regularity, it is proved that either every limit point of the iterate sequence is a Karush-Kuhn-Tucker
point of the barrier subproblem and the penalty parameter remains bounded, or there exists a limit point that is either an
infeasible stationary point of minimizing the ℓ
2 norm of violations of constraints of the original problem, or a Fritz-John point of the original problem. In addition, we
analyze the local convergence properties of the algorithm, and prove that by suitably controlling the exactness of range-space
steps and selecting the barrier parameter and Hessian approximation, the algorithm generates a superlinearly or quadratically
convergent step. The conditions on guaranteeing that all slack variables are still positive for a full step are presented. 相似文献
94.
This article presents a time-accurate numerical method using high-order accurate compact finite difference scheme for the incompressible Navier-Stokes equations. The method relies on the artificial compressibility formulation, which endows the governing equations a hyperbolic-parabolic nature. The convective terms are discretized with a third-order upwind compact scheme based on flux-difference splitting, and the viscous terms are approximated with a fourth-order central compact scheme. Dual-time stepping is implemented for time-accurate calculation in conjunction with Beam-Warming approximate factorization scheme. The present compact scheme is compared with an established non-compact scheme via analysis in a model equation and numerical tests in four benchmark flow problems. Comparisons demonstrate that the present third-order upwind compact scheme is more accurate than the non-compact scheme while having the same computational cost as the latter. 相似文献
95.
Wenqiang Pu Ya-Feng Liu Junkun Yan Hongwei Liu Zhi-Quan Luo 《Mathematical Programming》2018,170(1):357-386
An important step in a multi-sensor surveillance system is to estimate sensor biases from their noisy asynchronous measurements. This estimation problem is computationally challenging due to the highly nonlinear transformation between the global and local coordinate systems as well as the measurement asynchrony from different sensors. In this paper, we propose a novel nonlinear least squares formulation for the problem by assuming the existence of a reference target moving with an (unknown) constant velocity. We also propose an efficient block coordinate decent (BCD) optimization algorithm, with a judicious initialization, to solve the problem. The proposed BCD algorithm alternately updates the range and azimuth bias estimates by solving linear least squares problems and semidefinite programs. In the absence of measurement noise, the proposed algorithm is guaranteed to find the global solution of the problem and the true biases. Simulation results show that the proposed algorithm significantly outperforms the existing approaches in terms of the root mean square error. 相似文献
96.
We prove that the error estimates of a large class of nonconforming finite elements are dominated by their approximation errors, which means that the well-known Cea's lemma is still valid for these nonconforming finite element methods. Furthermore, we derive the error estimates in both energy and L2 norms under the regularity assumption u ∈ H1+s(Ω) with any s 0. The extensions to other related problems are possible. 相似文献
98.
99.
Ying Guang Shi 《Acta Mathematica Hungarica》1999,85(3):253-263
An explicit representation for the Cotes numbers of Turán quadrature formulas based on the zeros of the Chebyshev polynomials
of the second kind and its asymptotic behavior are given. The asymptotic formula for the corresponding Christoffel type functions
is also provided.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
100.
In solid state physics, the most widely used techniques to calculate the electronic levels in nanostructures are the effective masses approximation (EMA) and its extension the multiband k · p method (see [9]). They have been particularly successful in the case of heterostructures (see, e.g. [4], [9] and [11]). This paper discusses the multiscale analysis of the Schrödinger equation with rapidly oscillating coefficients. The new contributions obtained in this paper are the determination of the convergence rate for the approximate solutions, the definition of boundary layer solutions, and higher-order correctors. Consequently, a multiscale finite element method and some numerical results are presented. As one of the main results of this paper, we give a reasonable interpretation why the effective mass approximation is very accurate for calculating the band structures in semiconductor in the vicinity of Γ point, from the viewpoint of mathematics. 相似文献