全文获取类型
收费全文 | 3829篇 |
免费 | 405篇 |
国内免费 | 324篇 |
专业分类
化学 | 333篇 |
晶体学 | 14篇 |
力学 | 159篇 |
综合类 | 85篇 |
数学 | 3337篇 |
物理学 | 630篇 |
出版年
2024年 | 8篇 |
2023年 | 56篇 |
2022年 | 48篇 |
2021年 | 70篇 |
2020年 | 97篇 |
2019年 | 84篇 |
2018年 | 118篇 |
2017年 | 115篇 |
2016年 | 116篇 |
2015年 | 103篇 |
2014年 | 152篇 |
2013年 | 325篇 |
2012年 | 184篇 |
2011年 | 217篇 |
2010年 | 181篇 |
2009年 | 235篇 |
2008年 | 230篇 |
2007年 | 230篇 |
2006年 | 195篇 |
2005年 | 171篇 |
2004年 | 158篇 |
2003年 | 169篇 |
2002年 | 156篇 |
2001年 | 176篇 |
2000年 | 143篇 |
1999年 | 124篇 |
1998年 | 87篇 |
1997年 | 76篇 |
1996年 | 98篇 |
1995年 | 55篇 |
1994年 | 51篇 |
1993年 | 30篇 |
1992年 | 30篇 |
1991年 | 29篇 |
1990年 | 18篇 |
1989年 | 10篇 |
1988年 | 25篇 |
1987年 | 18篇 |
1986年 | 17篇 |
1985年 | 28篇 |
1984年 | 14篇 |
1983年 | 14篇 |
1982年 | 14篇 |
1981年 | 10篇 |
1980年 | 14篇 |
1979年 | 10篇 |
1978年 | 17篇 |
1977年 | 7篇 |
1976年 | 10篇 |
1974年 | 5篇 |
排序方式: 共有4558条查询结果,搜索用时 15 毫秒
971.
In this article,a degenerate and singular diffusion problem is studied.The ex- istence of solutions is established by parabolic regularization.Some properties of solutions, for instance,asymptotic behavior,are also discussed. 相似文献
972.
We prove that the probabilistic norms of suitable Probabilistic Normed spaces induce convergence in probability, Lp convergence and almost sure convergence. 相似文献
973.
本文应用特征有限元方法处理一类一维有界区域上的抛物型方程组,由于是第一类边界条件,对对流项系数作出假设,则避免了处理区域外的情况,最后给出收敛性定理.从误差结果看出,应用特征有限元可以增加时间步长,而不降低精度,数值实验也证实了这一点. 相似文献
974.
975.
V. Jeyanthi V. Jeyanthi V. Jeyanthi V. Renuka Devi V. Renuka Devi V. Renuka Devi D. Sivaraj D. Sivaraj D. Sivaraj 《Acta Mathematica Hungarica》2006,113(4):319-324
Summary Weakly I -continuous functions were introduced and studied by A?ikg?z, Noiri and Yüksel [1]. We further extend their study,
generalize some of their results and discuss its properties. 相似文献
976.
Marcel G. de Bruin 《Numerical Algorithms》2007,44(4):367-380
In this paper the classical convergence theorems by Śleszyński-Pringsheim, Worpitzky and Van Vleck for ordinary continued
fractions will be generalized to continued fractions generalizations (along the lines of the Jacobi–Perron algorithm) with
four-term recurrence relations.
相似文献
977.
We consider a mathematical program with complementarity constraints (MPCC). Our purpose is to develop methods that enable
us to compute a solution or a point with some kind of stationarity to MPCC by solving a finite number of nonlinear programs.
We apply an active set identification technique to a smoothing continuation method (Ref. 1) and propose a hybrid algorithm
for solving MPCC. We develop also two modifications: one makes use of an index addition strategy; the other adopts an index
subtraction strategy. We show that, under reasonable assumptions, all the proposed algorithms possess a finite termination
property. Further discussions and numerical experience are given as well
This work was supported in part by the Scientific Research Grant-in-Aid from the Ministry of Education, Science, Sports, and
Culture of Japan. The authors are grateful to Professor Paul Tseng for helpful suggestions on an earlier version of the paper. 相似文献
978.
提出了调制随机共振方法,实现了在大参数条件下从强噪声中检测微弱周期信号.将混于噪声中的较高频率的弱信号经调制变为一差频的低频信号作用于随机共振体系,该低频信号满足绝热近似理论,因而能产生随机共振;再经解调可获得埋于噪声中的原较高频率的弱信号.对埋于噪声中的未知频率,可采用连续改变调制振荡器的频率,以获得一个适当的差频信号输入到随机共振体系,根据输出信号共振谱峰的变化经解调而得待检弱信号的未知频率.该方法应具有较高的应用前景.
关键词:
调制与解调
非线性双稳系统
随机共振
微弱信号检测 相似文献
979.
Malek Ghazel Jameleddine Azzouz 《Journal of Mathematical Analysis and Applications》2007,333(2):712-730
In this paper, we study the weak convergence of “Leray-type” solutions of a magneto-hydro-dynamic systems. The proofs are based on weak compactness arguments and linear algebra methods. 相似文献
980.
G. E. Ivanov 《Mathematical Notes》2006,79(1-2):55-78
In this paper, the notion of a weakly convex set is introduced. Sharp estimates for the weak convexity constants of the sum and difference of such sets are given. It is proved that, in Hilbert space, the smoothness of a set is equivalent to the weak convexity of the set and its complement. Here, by definition, the smoothness of a set means that the field of unit outward normal vectors is defined on the boundary of the set; this vector field satisfies the Lipschitz condition. We obtain the minimax theorem for a class of problems with smooth Lebesgue sets of the goal function and strongly convex constraints. As an application of the results obtained, we prove the alternative theorem for program strategies in a linear differential quality game. 相似文献