全文获取类型
收费全文 | 2255篇 |
免费 | 647篇 |
国内免费 | 1334篇 |
专业分类
化学 | 920篇 |
晶体学 | 28篇 |
力学 | 139篇 |
综合类 | 58篇 |
数学 | 2335篇 |
物理学 | 756篇 |
出版年
2024年 | 10篇 |
2023年 | 46篇 |
2022年 | 49篇 |
2021年 | 75篇 |
2020年 | 55篇 |
2019年 | 41篇 |
2018年 | 32篇 |
2017年 | 49篇 |
2016年 | 48篇 |
2015年 | 64篇 |
2014年 | 209篇 |
2013年 | 205篇 |
2012年 | 241篇 |
2011年 | 167篇 |
2010年 | 368篇 |
2009年 | 279篇 |
2008年 | 418篇 |
2007年 | 316篇 |
2006年 | 182篇 |
2005年 | 132篇 |
2004年 | 81篇 |
2003年 | 126篇 |
2002年 | 88篇 |
2001年 | 158篇 |
2000年 | 210篇 |
1999年 | 125篇 |
1998年 | 61篇 |
1997年 | 37篇 |
1996年 | 40篇 |
1995年 | 72篇 |
1994年 | 70篇 |
1993年 | 51篇 |
1992年 | 28篇 |
1991年 | 20篇 |
1990年 | 35篇 |
1989年 | 23篇 |
1988年 | 8篇 |
1987年 | 3篇 |
1986年 | 2篇 |
1985年 | 3篇 |
1984年 | 3篇 |
1983年 | 5篇 |
1982年 | 1篇 |
排序方式: 共有4236条查询结果,搜索用时 59 毫秒
61.
Assume X is a normed space,every x * ∈ S(X*) can reach its norm at some point in B(X),and Y is a β-normed space.If there is a quotient space of Y which is asymptotically isometric to l β,then L(X,Y) contains an asymptotically isometric copy of l β.Some sufficient conditions are given under which L(X,Y) fails to have the fixed point property for nonexpansive mappings on closed bounded β-convex subsets of L(X,Y). 相似文献
62.
63.
This paper is devoted to studying the relationship between meromorphic functions f(z) and g(z) when their differential polynomials satisfy sharing condition weaker than sharing one value IM. 相似文献
64.
In this paper, we show that the hyponormal Toeplitz operator Tφ with trigonometric polynomial symbol φ is either normal or completely non-normal. Moreover, if Tφ is non-normal, then Tφ has a dense set of cyclic vectors. Some general conditions are also considered. 相似文献
65.
In this paper, we show that a multiplication operator on the Dirichlet space D is unitarily equivalent to Dirichlet shift of multiplicity n + 1 (n ≥ 0) if and only if its symbol is c zn+1 for some constant c. The result is very different from the cases of both the Bergman space and the Hardy space. 相似文献
66.
We give a direct proof to the classification of all indecomposable torsion modules over a Dedekind ring. As an application, we classify all indecomposable locally-nilpotent modules over the polynomial algebra with one variable over a field. 相似文献
67.
68.
For an inhomogeneous quasilinear hyperbolic system of diagonal form, under the assumptions that the system is linearly degenerate and the C^1 norm of the boundary data is bounded, we show that the mechanism of the formation of singularities of C^1 classical solution to the Goursat problem with C^1 compatibility conditions at the origin must be an ODE type. The similar result is also obtained for the weakly discontinuous solution with C^0 compatibility conditions at the origin. 相似文献
69.
A novel option pricing method based on Fourier-cosine series expansion was proposed by Fang and Oosterlee. Developing their idea, three new option pricing methods based on Fourier, Fourier-cosine and Fourier-sine series expansions are presented in this paper, which are more efficient when the option prices are calculated with many strike prices. A series of numerical experiments under different exp-L~vy models are also given to compare these new methods with the Fang and Oosterlee's method and other methods. 相似文献
70.
By employing the fixed point theorem of cone expansion and compression of norm type, we investigate the existence of positive solutions of generalized Sturm-Liouville boundary value problems for a nonlinear singular differential equation with a parameter. Some sufficient conditions for the existence of positive solutions are established. In the last section, an example is presented to illustrate the applications of our main results. 相似文献