首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   243篇
  免费   31篇
  国内免费   14篇
化学   7篇
力学   4篇
综合类   8篇
数学   239篇
物理学   30篇
  2023年   2篇
  2022年   5篇
  2021年   6篇
  2020年   2篇
  2019年   4篇
  2018年   2篇
  2017年   3篇
  2016年   7篇
  2015年   1篇
  2014年   8篇
  2013年   27篇
  2012年   26篇
  2011年   9篇
  2010年   17篇
  2009年   13篇
  2008年   18篇
  2007年   16篇
  2006年   14篇
  2005年   11篇
  2004年   12篇
  2003年   7篇
  2002年   9篇
  2001年   11篇
  2000年   4篇
  1999年   9篇
  1998年   5篇
  1997年   6篇
  1996年   7篇
  1995年   6篇
  1994年   1篇
  1993年   3篇
  1992年   1篇
  1991年   1篇
  1990年   1篇
  1989年   1篇
  1986年   1篇
  1985年   5篇
  1984年   1篇
  1983年   2篇
  1982年   2篇
  1981年   2篇
排序方式: 共有288条查询结果,搜索用时 31 毫秒
241.
本文研究了一类拟线性系统,引入了反周期边值条件,基于反周期边值条件和数学分析的技巧,建立了新的Lyapunov不等式.  相似文献   
242.
Lagrangian methods are popular in solving continuous constrained optimization problems. In this paper, we address three important issues in applying Lagrangian methods to solve optimization problems with inequality constraints.First, we study methods to transform inequality constraints into equality constraints. An existing method, called the slack-variable method, adds a slack variable to each inequality constraint in order to transform it into an equality constraint. Its disadvantage is that when the search trajectory is inside a feasible region, some satisfied constraints may still pose some effect on the Lagrangian function, leading to possible oscillations and divergence when a local minimum lies on the boundary of the feasible region. To overcome this problem, we propose the MaxQ method that carries no effect on satisfied constraints. Hence, minimizing the Lagrangian function in a feasible region always leads to a local minimum of the objective function. We also study some strategies to speed up its convergence.Second, we study methods to improve the convergence speed of Lagrangian methods without affecting the solution quality. This is done by an adaptive-control strategy that dynamically adjusts the relative weights between the objective and the Lagrangian part, leading to better balance between the two and faster convergence.Third, we study a trace-based method to pull the search trajectory from one saddle point to another in a continuous fashion without restarts. This overcomes one of the problems in existing Lagrangian methods that converges only to one saddle point and requires random restarts to look for new saddle points, often missing good saddle points in the vicinity of saddle points already found.Finally, we describe a prototype Novel (Nonlinear Optimization via External Lead) that implements our proposed strategies and present improved solutions in solving a collection of benchmarks.  相似文献   
243.
一类对称函数不等式的加细和推广   总被引:8,自引:1,他引:7  
利用控制不等式理论加细和推广了一类对称函数不等式,并给出一个几何应用。  相似文献   
244.
Let be the Kaplan-Meier estimator of distribution function F. Let J(˙) be a measurable real-valued function. In this paper, a U-statistic representation for the Kaplan-Meier L-estimator, , is derived. Furthermore, the representation is also used to establish a Berry-Essen inequality for . Received September 28, 1998, Accepted March 10, 1999  相似文献   
245.
陈凤祥  张卫东 《中国物理》2007,16(4):937-941
A technical framework of constructing a linear controller for chaotic synchronization by utilizing the stability theory of cascade-connected system is presented. Based on the method developed in the paper, two simple and linear feedback controllers, as examples, are derived for the synchronization of Liu chaotic system and Duffing oscillator, respectively. This method is quite flexible in constructing a control law. Its effectiveness is also illustrated by the simulation results.  相似文献   
246.
In this paper, we establish a generalization of Hadamard's inequality to r-convex functions on Carnot groups.  相似文献   
247.
In this short paper, we present time scales version of mean value theorems for integrals in the single variable case.  相似文献   
248.
In this paper we investigate a computational approach to keeping a moving particle within a predefined annulus or a predefined bounded space, formed by two concentric spheres with radii Lmin and Lmax, respectively, assuming that said particle cannot maintain a perfectly circular trajectory. The study develops an algorithm for dealing with a system in which constraints are expressed as inequalities. The proposed approach expresses the trajectory in terms of winding/unwinding logarithmic spirals with transitions, expressed as damped vibrations, between them. These transitions are necessary to resolve incompatibility between initial conditions for winding/unwinding spirals. Equations of motion for the particle are obtained by using the Fundamental Equation of Constrained Motion. The obtained simulation results show that such an approach produces the desired pseudo-periodic type of motion, and the particle stays within the predefined region of space for a long duration, although no cycle of its trajectory is repeated.  相似文献   
249.
Many, if not most, economies are observed to exhibit some form of collective ownership with some goods. These economies may fail to be socially stable, in the sense that the economy has an empty core; some groups may have an incentive to ‘recontract out’. We show that, for a class of economies with collective ownership, sufficient ‘specialization’ in the endowment holdings of these economies gives rise to a non-empty core, so achieving social stability. It is shown, moreover, that reductions in income inequality are consistent with social stability, to the extent that these reductions preserve or increase ‘specialization’ in the economy. Finally, we show that our notion of specialization is not limited to the privatized sector of the economy. Even in economies in which there is no privately held property, sufficient specialization guarantees that the economy is socially stable.  相似文献   
250.
Error bounds in mathematical programming   总被引:22,自引:0,他引:22  
Originated from the practical implementation and numerical considerations of iterative methods for solving mathematical programs, the study of error bounds has grown and proliferated in many interesting areas within mathematical programming. This paper gives a comprehensive, state-of-the-art survey of the extensive theory and rich applications of error bounds for inequality and optimization systems and solution sets of equilibrium problems. This work is based on research supported by the U.S. National Science Foundation under grant CCR-9624018.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号