全文获取类型
收费全文 | 17065篇 |
免费 | 1117篇 |
国内免费 | 1096篇 |
专业分类
化学 | 3440篇 |
晶体学 | 35篇 |
力学 | 982篇 |
综合类 | 167篇 |
数学 | 11575篇 |
物理学 | 3079篇 |
出版年
2024年 | 33篇 |
2023年 | 237篇 |
2022年 | 374篇 |
2021年 | 414篇 |
2020年 | 535篇 |
2019年 | 502篇 |
2018年 | 481篇 |
2017年 | 552篇 |
2016年 | 500篇 |
2015年 | 454篇 |
2014年 | 852篇 |
2013年 | 1701篇 |
2012年 | 807篇 |
2011年 | 939篇 |
2010年 | 795篇 |
2009年 | 1099篇 |
2008年 | 1207篇 |
2007年 | 1078篇 |
2006年 | 889篇 |
2005年 | 850篇 |
2004年 | 653篇 |
2003年 | 571篇 |
2002年 | 466篇 |
2001年 | 369篇 |
2000年 | 366篇 |
1999年 | 374篇 |
1998年 | 328篇 |
1997年 | 317篇 |
1996年 | 250篇 |
1995年 | 159篇 |
1994年 | 134篇 |
1993年 | 109篇 |
1992年 | 98篇 |
1991年 | 81篇 |
1990年 | 47篇 |
1989年 | 52篇 |
1988年 | 49篇 |
1987年 | 36篇 |
1986年 | 42篇 |
1985年 | 77篇 |
1984年 | 76篇 |
1983年 | 37篇 |
1982年 | 46篇 |
1981年 | 55篇 |
1980年 | 35篇 |
1979年 | 39篇 |
1978年 | 33篇 |
1977年 | 22篇 |
1976年 | 23篇 |
1973年 | 11篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
Isha Dewan B. L. S. Prakasa Rao 《Annals of the Institute of Statistical Mathematics》2003,55(1):111-119
Let {X
1, ...,X
m
} and {Y
1, ...,Y
n
} be two samples independent of each other, but the random variables within each sample are stationary associated with one
dimensional marginal distribution functionsF andG, respectively. We study the properties of the classical Wilcoxon-Mann-Whitney statistic for testing for stochastic dominance
in the above set up. 相似文献
82.
Z. Walczak 《Acta Mathematica Hungarica》2003,101(3):179-191
We consider certain modified Szász-Mirakyan operators A
n
(f;r) in polynomial weight spaces of functions of one variable and we study approximation properties of these operators.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
83.
Francesco Pappalardi 《Journal of Number Theory》2003,103(1):122-131
We obtain an asymptotic formula for the number of square-free values among p−1, for primes p?x, and we apply it to derive the following asymptotic formula for L(x), the number of square-free values of the Carmichael function λ(n) for 1?n?x,
84.
The main theme of this paper is that almost fixed point properties of discrete structures and fixed point properties of (topological) spaces are interdeducible via a suitable category which contains both graphs and spaces as objects. To carry out the program, we have to consider (almost) fixed points of multifunctions, and for this we need a preliminary discussion of power structures for graphs and simplicial complexes. Specific applications developed are: a digital convexity (discrete) version of Kakutani's fixed point theorem for convex-valued multifunctions; and fixed point properties of dendrites in terms of those of finite discrete trees. 相似文献
85.
A generalization of the Hilbert basis theorem in the geometric setting is proposed. It asserts that, for any well-describable (in a certain sense) family of polynomials, there exists a number C such that if P is an everywhere dense (in a certain sense) subfamily of this family, a is an arbitrary point, and the first C polynomials in any sequence from P vanish at the point a, then all polynomials from P vanish at a. 相似文献
86.
Hijazi Oussama Montiel Sebastin Roldn Antonio 《Annals of Global Analysis and Geometry》2003,23(3):247-264
We give a sharp extrinsic lower bound for the first eigenvaluesof the intrinsic Dirac operator of certain hypersurfaces boundinga compact domain in a spin manifold of negative scalar curvature.Limiting-cases are characterized by the existence, on the domain,of imaginary Killing spinors. Some geometrical applications, as anAlexandrov type theorem, are given. 相似文献
87.
Empirical likelihood for partial linear models 总被引:2,自引:0,他引:2
In this paper the empirical likelihood method due to Owen (1988,Biometrika,75, 237–249) is applied to partial linear random models. A nonparametric version of Wilks' theorem is derived. The theorem is
then used to construct confidence regions of the parameter vector in the partial linear models, which has correct asymptotic
coverage. A simulation study is conducted to compare the empirical likelihood and normal approximation based method.
Research supported by NNSF of China and a grant to the first author for his excellent Ph.D. dissertation work in China.
Research supported by Hong Kong RGC CERG No. HKUST6162/97P. 相似文献
88.
We describe the extension of the multiplication on a not-necessarily-discrete topological monoid to its flow compactification. We offer two applications. The first is a nondiscrete version of Hindman's Theorem, and the second is a characterization of the projective minimal and elementary flows in terms of idempotents of the flow compactification of the monoid. 相似文献
89.
The authors establish the Hilbertian invariance principle for the empirical process of a stationary Markov process, by extending the forward-backward martingale decomposition of Lyons-Meyer-Zheng to the Hilbert space valued additive functionals associated with general non-reversible Markov processes. 相似文献
90.
Using non-linear connection of Finsler manifold M, the existence of local coordinates which is normalized at a point x is proved, and the Laplace operator A on 1-form of M is defined by non-linear connection and its curvature tensor. After proving the maximum principle theorem of Hopf-Bochner on M, the Bochner type vanishing theorem of Killing vectors and harmonic 1-form are obtained. 相似文献