全文获取类型
收费全文 | 1343篇 |
免费 | 125篇 |
国内免费 | 86篇 |
专业分类
化学 | 24篇 |
力学 | 193篇 |
综合类 | 26篇 |
数学 | 1077篇 |
物理学 | 234篇 |
出版年
2024年 | 2篇 |
2023年 | 15篇 |
2022年 | 19篇 |
2021年 | 19篇 |
2020年 | 25篇 |
2019年 | 31篇 |
2018年 | 42篇 |
2017年 | 33篇 |
2016年 | 37篇 |
2015年 | 27篇 |
2014年 | 67篇 |
2013年 | 104篇 |
2012年 | 60篇 |
2011年 | 79篇 |
2010年 | 74篇 |
2009年 | 84篇 |
2008年 | 103篇 |
2007年 | 91篇 |
2006年 | 68篇 |
2005年 | 64篇 |
2004年 | 54篇 |
2003年 | 35篇 |
2002年 | 52篇 |
2001年 | 57篇 |
2000年 | 40篇 |
1999年 | 43篇 |
1998年 | 37篇 |
1997年 | 32篇 |
1996年 | 22篇 |
1995年 | 17篇 |
1994年 | 14篇 |
1993年 | 17篇 |
1992年 | 15篇 |
1991年 | 18篇 |
1990年 | 11篇 |
1989年 | 5篇 |
1988年 | 7篇 |
1987年 | 3篇 |
1985年 | 4篇 |
1984年 | 3篇 |
1983年 | 2篇 |
1982年 | 4篇 |
1981年 | 5篇 |
1980年 | 2篇 |
1979年 | 4篇 |
1977年 | 4篇 |
1976年 | 1篇 |
1975年 | 1篇 |
1971年 | 1篇 |
排序方式: 共有1554条查询结果,搜索用时 0 毫秒
21.
In recent years, Landweber iteration has been extended to solve linear inverse problems in Banach spaces by incorporating non-smooth convex penalty functionals to capture features of solutions. This method is known to be slowly convergent. However, because it is simple to implement, it still receives a lot of attention. By making use of the subspace optimization technique, we propose an accelerated version of Landweber iteration with non-smooth convex penalty which significantly speeds up the method. Numerical simulations are given to test the efficiency. 相似文献
22.
对解强刚性块线代数方程组X=(A(?)J)X φ,本文提出了L-收敛的最佳单参数迭代法(L-OOPI)和L-收敛的多参数迭代直接法(L-MPID),并给出了数值例子.数例表明,对于强刚性块线代数方程组,该二迭代法是有效的. 相似文献
23.
用带误差项的Ishikawa迭代过程逼近φ-强增生算子的零点 总被引:18,自引:0,他引:18
本文使用新的分析技巧研究了一致光滑Banach空间中φ 强增生算子的零点逼近问题,所得结果改进和扩展了近期许多相应的结果 相似文献
24.
张文丽 《应用泛函分析学报》2014,(4):346-350
研究了—(p,q)-Laplacian拟线性椭圆方程组.当连续函数V和W在两种情形下,利用Moser迭代技巧和Ljusternik-Schnirelmann畴数理论,建立了方程组正解的存在性和多重性结果. 相似文献
25.
本文对求解大型线性方程组的异步并行迭代法进行了浮点运算的舍入误差分析,给出了算法是向前稳定的充分条件. 相似文献
26.
27.
Newton's method on Riemannian manifolds: covariant alpha theory 总被引:5,自引:0,他引:5
Dedieu Jean-Pierre; Priouret Pierre; Malajovich Gregorio 《IMA Journal of Numerical Analysis》2003,23(3):395-419
In this paper, Smale's theory is generalized to the contextof intrinsic Newton iteration on geodesically complete analyticRiemannian and Hermitian manifolds. Results are valid for analyticmappings from a manifold to a linear space of the same dimension,or for analytic vector fields on the manifold. The invariant is defined by means of high-order covariant derivatives. Boundson the size of the basin of quadratic convergence are given.If the ambient manifold has negative sectional curvature, thosebounds depend on the curvature. A criterion of quadratic convergencefor Newton iteration from the information available at a pointis also given. 相似文献
28.
Wei Li Jicheng Li 《高等学校计算数学学报(英文版)》2007,16(4):313-319
The large scale linear systems with M-matrices often appear in a wide variety of areas of physical,fluid dynamics and economic sciences.It is reported in[1]that the convergence rate of the IMGS method,with the preconditioner I S_α,is superior to that of the basic SOR iterative method for the M-matrix.This paper considers the preconditioned Jacobi(PJ)method with the preconditioner P=I S_α S_β,and proves theoretically that the convergence rate of the PJ method is better than that of the basic AOR method.Numerical examples are provided to illustrate the main results obtained. 相似文献
29.
We present an iterative semi-implicit scheme for the incompressible Navier–Stokes equations, which is stable at CFL numbers well above the nominal limit. We have implemented this scheme in conjunction with spectral discretizations, which suffer from serious time step limitations at very high resolution. However, the approach we present is general and can be adopted with finite element and finite difference discretizations as well. Specifically, at each time level, the nonlinear convective term and the pressure boundary condition – both of which are treated explicitly in time – are updated using fixed-point iteration and Aitken relaxation. Eigenvalue analysis shows that this scheme is unconditionally stable for Stokes flows while numerical results suggest that the same is true for steady Navier–Stokes flows as well. This finding is also supported by error analysis that leads to the proper value of the relaxation parameter as a function of the flow parameters. In unsteady flows, second- and third-order temporal accuracy is obtained for the velocity field at CFL number 5–14 using analytical solutions. Systematic accuracy, stability, and cost comparisons are presented against the standard semi-implicit method and a recently proposed fully-implicit scheme that does not require Newton’s iterations. In addition to its enhanced accuracy and stability, the proposed method requires the solution of symmetric only linear systems for which very effective preconditioners exist unlike the fully-implicit schemes. 相似文献
30.