全文获取类型
收费全文 | 4932篇 |
免费 | 463篇 |
国内免费 | 343篇 |
专业分类
化学 | 733篇 |
晶体学 | 10篇 |
力学 | 353篇 |
综合类 | 82篇 |
数学 | 3058篇 |
物理学 | 1502篇 |
出版年
2023年 | 39篇 |
2022年 | 85篇 |
2021年 | 92篇 |
2020年 | 94篇 |
2019年 | 111篇 |
2018年 | 89篇 |
2017年 | 139篇 |
2016年 | 168篇 |
2015年 | 111篇 |
2014年 | 267篇 |
2013年 | 337篇 |
2012年 | 190篇 |
2011年 | 279篇 |
2010年 | 275篇 |
2009年 | 273篇 |
2008年 | 306篇 |
2007年 | 371篇 |
2006年 | 286篇 |
2005年 | 249篇 |
2004年 | 246篇 |
2003年 | 246篇 |
2002年 | 197篇 |
2001年 | 149篇 |
2000年 | 153篇 |
1999年 | 142篇 |
1998年 | 115篇 |
1997年 | 106篇 |
1996年 | 72篇 |
1995年 | 91篇 |
1994年 | 58篇 |
1993年 | 50篇 |
1992年 | 48篇 |
1991年 | 37篇 |
1990年 | 29篇 |
1989年 | 24篇 |
1988年 | 23篇 |
1987年 | 24篇 |
1986年 | 16篇 |
1985年 | 26篇 |
1984年 | 19篇 |
1983年 | 14篇 |
1982年 | 13篇 |
1981年 | 14篇 |
1980年 | 14篇 |
1979年 | 12篇 |
1978年 | 8篇 |
1977年 | 10篇 |
1976年 | 5篇 |
1975年 | 4篇 |
1973年 | 3篇 |
排序方式: 共有5738条查询结果,搜索用时 93 毫秒
11.
In this note we show how coverings induced by voltage assignments can be used to produce packings of disjoint copies of the Hoffman‐Singleton graph into K50. © 2003 Wiley Periodicals, Inc. J Combin Designs 11: 408–412, 2003; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/jcd.10049 相似文献
12.
A. Khrennikov 《Annalen der Physik》2003,12(10):575-585
We study the probabilistic consequences of the choice of the basic number field in the quantum formalism. We demonstrate that by choosing a number field for a linear space representation of quantum model it is possible to describe various interference phenomena. We analyse interference of probabilistic alternatives induced by real, complex, hyperbolic (Clifford) and p‐adic representations. 相似文献
13.
Dan Voiculescu 《Reports on Mathematical Physics》2005,55(1):127-133
This short note summarizes the circumstances of the birth of free probability theory andsome of the recent achievements. 相似文献
14.
Arnon Arazi Eshel Ben-Jacob Uri Yechiali 《Mathematical Methods of Operations Research》2005,62(3):453-466
We consider a Jackson-type network comprised of two queues having state-dependent service rates, in which the queue lengths
evolve periodically, exhibiting noisy cycles. To reduce this noise a certain heuristic, utilizing regions in the phase space
in which the system behaves almost deterministically, is applied. Using this heuristic, we show that in order to decrease
the probability of a customers overflow in one of the queues in the network, the server in that same queue – contrary to intuition
– should be shut down for a short period of time. Further noise reduction is obtained if the server in the second queue is
briefly shut down as well, when certain conditions hold. 相似文献
15.
We establish a relation between stable distributions in probability theory and the fractional integral. Moreover, it turns out that the parameter of the stable distribution coincides with the exponent of the fractional integral. It follows from an analysis of the obtained results that equations with the fractional time derivative describe the evolution of some physical system whose time degree of freedom becomes stochastic, i.e., presents a sum of random time intervals subject to a stable probability distribution. We discuss relations between the fractal Cantor set (Cantor strips) and the fractional integral. We show that the possibility to use this relation as an approximation of the fractional integral is rather limited. 相似文献
16.
稀疏过程在破产问题中的应用 总被引:5,自引:0,他引:5
本讨论一类人寿保险的风险过程,其中保单到达服从齐次Poisson过程。而描述退保及索赔发生的计数过程分别为这一过程的q-稀疏与p-稀疏.对此模型给出其破产概率的具体上界,并与其它一类风险模型进行比较. 相似文献
17.
18.
Hans TRIEBEL 《应用数学学报(英文版)》2004,(4)
The paper deals with multifractal quantities for some types of Radon measures,especiallyself-similar probability measures,and their relations to Besov spaces. 相似文献
19.
The form of the probability density derived from the evolution in time of a previously truncated frequency distribution of animal Liveweights is of interest in animal husbandry. Truncated frequency distributions arise when the heavier animals are sold for slaughter and the lighter animals retained. The demands of modern quality assurance schemes require that, given information on animal growth, the farmer is able to estimate the number of animals that would meet the specifications at some time in the future after truncation. Assuming that animal growth can be described by a linear stochastic differential equation, we derive an explicit expression for the probability density of animal Liveweights at any time after the truncation of an initial Gaussian density. It is shown that this probability density converges rapidly to a Gaussian density, so that after about 20 days of typical growth rates for lambs, the resulting density is practically indistinguishable from Gaussian. 相似文献
20.
工程施工中运输网络优化方案 总被引:5,自引:0,他引:5
施工工地运输方案的优化设计可以归结为 :按施工期要求设计运输线路或验证已有线路通行能力 ,计算总线路中影响提高流量的关键路段 ,取得最小费用最大流 .本文运用图论理论这一数学工具把实际问题抽象为有向网络 ,进而建立数学模型 .此方法理论上严密 ,解题步聚直观清晰 ,对水利、公路、水路、铁路等其它运输系统有普遍意义 . 相似文献