全文获取类型
收费全文 | 6655篇 |
免费 | 565篇 |
国内免费 | 602篇 |
专业分类
化学 | 613篇 |
晶体学 | 24篇 |
力学 | 353篇 |
综合类 | 151篇 |
数学 | 5980篇 |
物理学 | 701篇 |
出版年
2024年 | 9篇 |
2023年 | 45篇 |
2022年 | 100篇 |
2021年 | 140篇 |
2020年 | 120篇 |
2019年 | 141篇 |
2018年 | 130篇 |
2017年 | 204篇 |
2016年 | 216篇 |
2015年 | 134篇 |
2014年 | 305篇 |
2013年 | 509篇 |
2012年 | 309篇 |
2011年 | 395篇 |
2010年 | 343篇 |
2009年 | 427篇 |
2008年 | 462篇 |
2007年 | 490篇 |
2006年 | 397篇 |
2005年 | 352篇 |
2004年 | 335篇 |
2003年 | 295篇 |
2002年 | 274篇 |
2001年 | 236篇 |
2000年 | 222篇 |
1999年 | 171篇 |
1998年 | 185篇 |
1997年 | 163篇 |
1996年 | 135篇 |
1995年 | 89篇 |
1994年 | 76篇 |
1993年 | 47篇 |
1992年 | 37篇 |
1991年 | 41篇 |
1990年 | 37篇 |
1989年 | 20篇 |
1988年 | 22篇 |
1987年 | 20篇 |
1986年 | 11篇 |
1985年 | 24篇 |
1984年 | 22篇 |
1983年 | 30篇 |
1982年 | 20篇 |
1981年 | 24篇 |
1980年 | 22篇 |
1979年 | 14篇 |
1978年 | 11篇 |
1977年 | 3篇 |
1969年 | 1篇 |
1959年 | 2篇 |
排序方式: 共有7822条查询结果,搜索用时 709 毫秒
61.
The parallel version of precondition techniques is developed for matrices arising from the Galerkin boundary element method for two-dimensional domains with Dirichlet boundary conditions. Results were obtained for implementations on a transputer network as well as on an nCUBE-2 parallel computer showing that iterative solution methods are very well suited for a MIMD computer. A comparison of numerical results for iterative and direct solution methods is presented and underlines the superiority of iterative methods for large systems. 相似文献
62.
无穷区间上二阶微分方程的边值问题 总被引:5,自引:0,他引:5
刘衍胜 《应用泛函分析学报》2002,4(3):211-216
利用Schauder不动点定理讨论了一类非线性二阶微分方程在无穷区间上的边值问题无界解的存在性,部分改进了郭大钧教授最近得到的结果。 相似文献
63.
Gisella Facchinetti 《Fuzzy Optimization and Decision Making》2002,1(3):313-327
In this paper we present two definitions of possibilistic weighted average of fuzzy numbers, and by them we introduce two different rankings on the set of real fuzzy numbers. The two methods are dependent on several parameters. In the first case, the parameter is constant and the results generalize what Carlsson and Fuller have obtained in (2001). In the second case, the parameter is a function, not fixed a priori by the decision maker, but it depends on the position of the interval on the real axe. In all the two cases we call the parameter degree of risk, which takes into account of a risk-tendency or aversion of the decision maker. 相似文献
64.
用于留数算术中的数值/留数/数值的转换 总被引:1,自引:0,他引:1
介绍用光学方法完成留数算术中的数值/留数/数值的转换,并附有实验结果。 相似文献
65.
An initial boundary value problem for the dynamic system of anisotropic elasticity in a half space is studied in the paper. A novel method of finding an exact solution of this problem for a special polynomial form of initial data and inhomogeneous term of the system is described. On the base of this method the simulation of elastic waves in different homogeneous anisotropic half spaces is implemented. 相似文献
66.
Closed series solution of electromagnetic scattering by an eccentric coated cylinder is achieved in matrix form. Diffracted field patterns are examined for an incident plane transverse magnetic (TM) wave. The solution is found by the classical separation of variables technique and the translational addition theorems. Wave transformation and orthogonality of the complex exponentials are employed to produce an infinite series. Numerical results are then shown by shortening the infinite series to a limited number of terms. Solutions are discussed for a dielectric or a metamaterial coating. 相似文献
67.
给出了 n元函数极值的一个充分条件 ,并结合矩阵的初等变换建立了 n元函数极值的一种快速判别法 ,最后给出了一个例子 相似文献
68.
69.
Wing-Sum Cheung Patricia J.Y. Wong 《Journal of Mathematical Analysis and Applications》2007,329(2):851-869
We consider a system of focal boundary value problems where the nonlinearities may be singular in the independent variable and may also be singular in the dependent arguments. Using Schauder fixed point theorem, we establish criteria such that the system of boundary value problems has at least one fixed-sign solution. 相似文献
70.
In this paper we deal with nonlinear second-order boundary value problems with impulses. The impulsive functions depend implicitly on the different considered variables and the boundary value conditions are nonlinear. In both cases functional dependence on the solution is allowed. The existence results follow from the existence of a pair of well-ordered lower and upper solutions. 相似文献