全文获取类型
收费全文 | 9297篇 |
免费 | 1149篇 |
国内免费 | 547篇 |
专业分类
化学 | 1629篇 |
晶体学 | 46篇 |
力学 | 1698篇 |
综合类 | 195篇 |
数学 | 4038篇 |
物理学 | 3387篇 |
出版年
2024年 | 30篇 |
2023年 | 91篇 |
2022年 | 254篇 |
2021年 | 270篇 |
2020年 | 325篇 |
2019年 | 273篇 |
2018年 | 252篇 |
2017年 | 316篇 |
2016年 | 369篇 |
2015年 | 265篇 |
2014年 | 405篇 |
2013年 | 674篇 |
2012年 | 445篇 |
2011年 | 496篇 |
2010年 | 397篇 |
2009年 | 476篇 |
2008年 | 474篇 |
2007年 | 488篇 |
2006年 | 479篇 |
2005年 | 400篇 |
2004年 | 356篇 |
2003年 | 392篇 |
2002年 | 356篇 |
2001年 | 307篇 |
2000年 | 347篇 |
1999年 | 268篇 |
1998年 | 241篇 |
1997年 | 196篇 |
1996年 | 163篇 |
1995年 | 123篇 |
1994年 | 138篇 |
1993年 | 114篇 |
1992年 | 108篇 |
1991年 | 97篇 |
1990年 | 84篇 |
1989年 | 64篇 |
1988年 | 64篇 |
1987年 | 49篇 |
1986年 | 34篇 |
1985年 | 47篇 |
1984年 | 58篇 |
1983年 | 30篇 |
1982年 | 27篇 |
1981年 | 32篇 |
1980年 | 17篇 |
1979年 | 21篇 |
1978年 | 18篇 |
1977年 | 11篇 |
1976年 | 12篇 |
1957年 | 7篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
31.
A set of vertices is shattered in a hypergraph if any of its subsets is obtained as the intersection of an edge with the set. The VC dimension is the size of the largest shattered subset. Under the binomial model of k‐uniform random hypergraphs, the threshold function for the VC dimension to be larger than a given integer is obtained. The same is done for the testing dimension, which is the largest integer d such that all sets of cardinality d are shattered. © 2006 Wiley Periodicals, Inc. Random Struct. Alg., 2007 相似文献
32.
张国胜 《数学的实践与认识》2006,36(7):356-367
设W(1n)W2(n)…W(nn)是严平稳随即序列{Xn,n 1}的前几个变量的顺序统计量,Nn Mn是两正整值r.v,n 1.在较弱一些的混合条件下,本文给出了W(NMn)n标准化后的极限分布,从而使一些提法更趋一般化,主要结果推进了Rao(1984)和张国胜(1993)的工作.由于混合条件的减弱,使得对m-相关和正态平稳过程的具体应用讨论更加充分. 相似文献
33.
S. V. Dil’man 《Mathematical Notes》2006,79(5-6):625-631
In 1996, D. Deng established an analog of the Baum—Katz theorem on the convergence rate in the law of large numbers for multi-indexed random variables. The series describing the convergence rate depends, in a natural way, on the parameter characterizing the excess of the normalized sums over some level. In this paper, we find the precise asymptotics of the sum of this series with respect to the above-mentioned parameter. Thus, a generalization of a recent result due to A. Gut and A. Spataru is obtained. 相似文献
34.
In this article,the Hausdorff dimension and exact Hausdorff measure function of any random sub-self-similar set are obtained under some reasonable conditions.Several examples are given at the end. 相似文献
35.
Fuzzy random vector is a measurable map from a probability space to a collection of fuzzy vectors. Our aim in this paper is
to discuss the measurability criteria for fuzzy random vectors, and show that under mild assumption, the measurability criteria
for upper semicontinuous fuzzy random vectors can be expressed in several different but equivalent formulations. Finally,
applying the obtained results, we resolve an open problem about the relationship between fuzzy random vectors and fuzzy random
variables. 相似文献
36.
We construct random locally compact real trees called Lévy trees that are the genealogical trees associated with continuous-state
branching processes. More precisely, we define a growing family of discrete Galton–Watson trees with i.i.d. exponential branch
lengths that is consistent under Bernoulli percolation on leaves; we define the Lévy tree as the limit of this growing family
with respect to the Gromov–Hausdorff topology on metric spaces. This elementary approach notably includes supercritical trees
and does not make use of the height process introduced by Le Gall and Le Jan to code the genealogy of (sub)critical continuous-state
branching processes. We construct the mass measure of Lévy trees and we give a decomposition along the ancestral subtree of
a Poisson sampling directed by the mass measure.
T. Duquesne is supported by NSF Grants DMS-0203066 and DMS-0405779. M. Winkel is supported by Aon and the Institute of Actuaries,
EPSRC Grant GR/T26368/01, le département de mathématique de l’Université d’Orsay and NSF Grant DMS-0405779. 相似文献
37.
J. -R. Chazottes P. Collet C. Külske F. Redig 《Probability Theory and Related Fields》2007,137(1-2):201-225
We present a new and simple approach to concentration inequalities in the context of dependent random processes and random
fields. Our method is based on coupling and does not use information inequalities. In case one has a uniform control on the
coupling, one obtains exponential concentration inequalities. If such a uniform control is no more possible, then one obtains
polynomial or stretched-exponential concentration inequalities. Our abstract results apply to Gibbs random fields, both at
high and low temperatures and in particular to the low-temperature Ising model which is a concrete example of non-uniformity
of the coupling.
相似文献
38.
We study a class of ‘nonpoissonian’ transformations of the configuration space and the corresponding transformations of the Poisson measure. For some class of Poisson measures we find conditions which are sufficient for the transformed measure (which in general is nonpoissonian) to be absolutely continuous with respect to the initial Poisson measure and get the expression for the corresponding Radon–Nikodym derivative. To solve this problem we use a distributional approach to Poisson multiple stochastic integrals. 相似文献
39.
[1]中提出了具有功能反应的三种群捕食者——食饵系统的两种模型(Ⅰ)、(Ⅱ),并给出了局部渐近稳定的条件。本文研究了另外两种模型(Ⅲ)和(Ⅳ)的局部渐近稳定的条件。 相似文献
40.