全文获取类型
收费全文 | 13569篇 |
免费 | 2443篇 |
国内免费 | 745篇 |
专业分类
化学 | 2086篇 |
晶体学 | 79篇 |
力学 | 857篇 |
综合类 | 144篇 |
数学 | 4303篇 |
物理学 | 3952篇 |
无线电 | 5336篇 |
出版年
2024年 | 25篇 |
2023年 | 138篇 |
2022年 | 245篇 |
2021年 | 349篇 |
2020年 | 409篇 |
2019年 | 414篇 |
2018年 | 390篇 |
2017年 | 528篇 |
2016年 | 579篇 |
2015年 | 568篇 |
2014年 | 788篇 |
2013年 | 1108篇 |
2012年 | 913篇 |
2011年 | 977篇 |
2010年 | 787篇 |
2009年 | 799篇 |
2008年 | 892篇 |
2007年 | 845篇 |
2006年 | 773篇 |
2005年 | 671篇 |
2004年 | 583篇 |
2003年 | 589篇 |
2002年 | 524篇 |
2001年 | 452篇 |
2000年 | 387篇 |
1999年 | 335篇 |
1998年 | 251篇 |
1997年 | 256篇 |
1996年 | 197篇 |
1995年 | 165篇 |
1994年 | 123篇 |
1993年 | 93篇 |
1992年 | 75篇 |
1991年 | 75篇 |
1990年 | 54篇 |
1989年 | 49篇 |
1988年 | 34篇 |
1987年 | 36篇 |
1986年 | 32篇 |
1985年 | 53篇 |
1984年 | 33篇 |
1983年 | 18篇 |
1982年 | 28篇 |
1981年 | 25篇 |
1980年 | 9篇 |
1979年 | 19篇 |
1978年 | 14篇 |
1977年 | 13篇 |
1976年 | 11篇 |
1973年 | 6篇 |
排序方式: 共有10000条查询结果,搜索用时 928 毫秒
941.
研究了具有HollingII类型功能反应的一捕食者有两个食饵的时滞系统,通过构造Lyapunov泛函得到了与时滞有关的系统全局渐近稳定的充分条件. 相似文献
942.
研究保费收取过程是一个随机过程的双险种风险模型,得出了Lundberg上界、最终破产概率、不破产所满足的微积分方程、索赔服从指数分布的不破产概率、有限时间不破产所满足的微积分方程. 相似文献
943.
We consider a discrete time single server queueing system where the arrival process is governed by a discrete autoregressive
process of order p (DAR(p)), and the service time of a customer is one slot. For this queueing system, we give an expression for the mean queue size,
which yields upper and lower bounds for the mean queue size. Further we propose two approximation methods for the mean queue
size. One is based on the matrix analytic method and the other is based on simulation. We show, by illustrations, that the
proposed approximations are very accurate and computationally efficient. 相似文献
944.
Alexander Mielke Adrien Petrov 《Journal of Mathematical Analysis and Applications》2008,348(2):1012-1020
This paper discusses the convergence of kinetic variational inequalities to rate-independent quasi-static variational inequalities. Mathematical formulations as well as existence and uniqueness results for kinetic and rate-independent quasi-static problems are provided. Sharp a priori estimates for the kinetic problem are derived that imply that the kinetic solutions converge to the rate-independent ones, when the size of initial perturbations and the rate of application of the forces tend to 0. An application to three-dimensional elastic-plastic systems with hardening is given. 相似文献
945.
In this paper, a theorem on the moderate deviation principle for random arrays under m-dependence with unbounded m is established. This partially extends the results of Chen (Stat. Probab. Lett. 35:123–134, 1997). As an application, the moderate deviation principle for the truncation estimator of the variance in the analysis of time
series is obtained.
相似文献
946.
S. Minkevičius 《Acta Appl Math》2008,104(3):271-285
The model of an open queueing network in heavy traffic has been developed. These models are mathematical models of computer
networks in heavy traffic. A limit theorem has been presented for the virtual waiting time of a customer in heavy traffic
in open queueing networks. Finally, we present an application of the theorem—a reliability model from computer network practice. 相似文献
947.
948.
In this paper, general conditions of state classification for the total weighted occupation times of a class of infinitely
divisible superprocesses on a bounded domain D in ℝ
d
are given. As an application, some sufficient and necessary conditions are found for the total weighted occupation times
of some special superprocesses on D to be absolutely continuous or singular with respect to the Lebesgue measure on D.
The research of Yan-Xia Ren is supported by NNSF of China (Grant No. 10471003) and Foundation for Authors Awarded Excellent
Ph.D. Dissertation. 相似文献
949.
950.
A scheme for creating an arbitrary coherent superposition of two atomic states in serial multi-A-type system is proposed.This technique with the application of a control field is based on the existence of two degenerate dark states and their interaction.The mixing of the dark states can be controlled by changing the relative delay time of the control pulse.One can get any desired superposition by changing the delay time of the control pulse. 相似文献