全文获取类型
收费全文 | 4808篇 |
免费 | 613篇 |
国内免费 | 166篇 |
专业分类
化学 | 140篇 |
力学 | 466篇 |
综合类 | 55篇 |
数学 | 3726篇 |
物理学 | 1200篇 |
出版年
2023年 | 39篇 |
2022年 | 70篇 |
2021年 | 111篇 |
2020年 | 149篇 |
2019年 | 124篇 |
2018年 | 138篇 |
2017年 | 150篇 |
2016年 | 169篇 |
2015年 | 102篇 |
2014年 | 200篇 |
2013年 | 551篇 |
2012年 | 238篇 |
2011年 | 210篇 |
2010年 | 221篇 |
2009年 | 225篇 |
2008年 | 221篇 |
2007年 | 233篇 |
2006年 | 232篇 |
2005年 | 228篇 |
2004年 | 169篇 |
2003年 | 174篇 |
2002年 | 157篇 |
2001年 | 170篇 |
2000年 | 184篇 |
1999年 | 123篇 |
1998年 | 125篇 |
1997年 | 105篇 |
1996年 | 79篇 |
1995年 | 73篇 |
1994年 | 67篇 |
1993年 | 50篇 |
1992年 | 58篇 |
1991年 | 46篇 |
1990年 | 41篇 |
1989年 | 33篇 |
1988年 | 32篇 |
1987年 | 24篇 |
1986年 | 26篇 |
1985年 | 45篇 |
1984年 | 37篇 |
1983年 | 14篇 |
1982年 | 26篇 |
1981年 | 16篇 |
1980年 | 13篇 |
1979年 | 16篇 |
1978年 | 12篇 |
1977年 | 20篇 |
1976年 | 11篇 |
1973年 | 6篇 |
1972年 | 5篇 |
排序方式: 共有5587条查询结果,搜索用时 15 毫秒
131.
《Annals of Differential Equations》2012,(3):283-289
By applying the properties of almost periodic function and exponential dichotomy of linear system as well as Banach fixed point theorem,we establish the conditions for the existence and uniqueness of square-mean almost periodic solution to some stochastic functional differential equations. 相似文献
132.
The extinction phenomenon induced by multiplicative non-Gaussian Levy noise in a tumor growth model with immune response is discussed. Under the influence of the stochastic immune rate, the model is analyzed in terms of a stochastic differential equation with multiplicative noise. By means of the theory of the infinitesimal generator of Hunt processes, the escape probability, which is used to measure the noise-induced extinction probability of tumor cells, is explicitly expressed as a function of initial tumor cell density, stability index and noise intensity. Based on the numerical calculations, it is found that for different initial densities of tumor cells, noise parameters play opposite roles on the escape probability. The optimally selected values of the multiplicative noise intensity and the stability index are found to maximize the escape probability. 相似文献
133.
A.B. Sow 《Stochastics An International Journal of Probability and Stochastic Processes》2013,85(5):429-477
Using a forward–backward stochastic differential equations (FBSDE) associated to a transmutation process driven by a finite sequence of Poisson processes, we obtain a probabilistic interpretation for a non-degenerate system of quasilinear parabolic partial differential equations (PDEs). The novetly is that the linear second order differential operator is different on each line of the system. 相似文献
134.
提出了一种新的能反映决策者满意度的随机变量序关系,并据此研究了随机不等式的确定性等价类,方法被称为满意度方法.最后将其应用于带凹性生产成本运输问题的求解中,并将方法与常用的机会约束方法进行比较,说明满意度法不仅合理可行,而且当决策者对约束条件的要求越高时,它所得最优值越优于机会约束法所得最优值. 相似文献
135.
A microscopic cluster model with a fully correlated Gaussian basis is developed. In the model, the stochastic variational method is used in order to calculate the ground-energy and the mean-square radius conveniently. Based on this model, the ground-energy level and radius of the neutron halo nucleus, <'6>He, are calculated as a α+n+n three-cluster model. The results are in good agreement with the experimental data. 相似文献
136.
The cumulative Kullback–Leibler information has been proposed recently as a suitable extension of Kullback–Leibler information to the cumulative distribution function. In this paper, we obtain various results on such a measure, with reference to its relation with other information measures and notions of reliability theory. We also provide some lower and upper bounds. A dynamic version of the cumulative Kullback–Leibler information is then proposed for past lifetimes. Furthermore, we investigate its monotonicity property, which is related to some new concepts of relative aging. Moreover, we propose an application to the failure of nanocomponents. Finally, in order to provide an application in image analysis, we introduce the empirical cumulative Kullback–Leibler information and prove an asymptotic result. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
137.
Approximation properties for solutions to non‐Lipschitz stochastic differential equations with Lévy noise 下载免费PDF全文
In this paper, we consider the non‐Lipschitz stochastic differential equations and stochastic functional differential equations with delays driven by Lévy noise, and the approximation theorems for the solutions to these two kinds of equations will be proposed respectively. Non‐Lipschitz condition is much weaker condition than the Lipschitz one. The simplified equations will be defined to make its solutions converge to that of the corresponding original equations both in the sense of mean square and probability, which constitute the approximation theorems. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
138.
Existence results of stochastic impulsive systems with expectations‐dependent nonlinear terms 下载免费PDF全文
In this paper, sufficient conditions are established for the existence and uniqueness of global solutions to stochastic impulsive systems with expectations in the nonlinear terms. The maximal interval and the estimate of mild solutions are also discussed. These results are obtained by using the fixed point theorem, interval partition, and Lyapunov‐like technique. Finally, examples are given to illustrate the theory. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
139.
A deductive approach to the solution of the problem of optimal pairs trading from the viewpoint of stochastic control with time‐dependent parameters 下载免费PDF全文
K. Charalambous C. Sophocleous J. G. O'Hara P. G. L. Leach 《Mathematical Methods in the Applied Sciences》2015,38(17):4448-4460
In a fairly recent paper (2008 American Control Conference, June 11‐13, 1035‐1039), the problem of dealing with trading in optimal pairs was treated from the viewpoint of stochastic control. The analysis of the subsequent nonlinear evolution partial differential equation was based upon a succession of Ansätze, which can lead to a solution of the terminal‐value problem. Through an application of the Lie Theory of Continuous Groups to this equation, we show that the Ansätze are based upon the underlying symmetries of the equation (their (14)). We solve the problem in a more general context by allowing the parameters to be explicitly time dependent. The extension means thatmore realistic problems are amenable to the samemode of solution. Copyright © 2014 JohnWiley & Sons, Ltd. 相似文献
140.