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   1572篇
  免费   219篇
  国内免费   40篇
化学   435篇
力学   6篇
综合类   10篇
数学   1231篇
物理学   149篇
  2023年   14篇
  2022年   31篇
  2021年   44篇
  2020年   67篇
  2019年   48篇
  2018年   60篇
  2017年   43篇
  2016年   70篇
  2015年   50篇
  2014年   67篇
  2013年   111篇
  2012年   64篇
  2011年   94篇
  2010年   58篇
  2009年   77篇
  2008年   86篇
  2007年   69篇
  2006年   61篇
  2005年   70篇
  2004年   60篇
  2003年   59篇
  2002年   43篇
  2001年   46篇
  2000年   47篇
  1999年   34篇
  1998年   36篇
  1997年   14篇
  1996年   21篇
  1995年   20篇
  1994年   20篇
  1993年   9篇
  1992年   21篇
  1991年   15篇
  1990年   18篇
  1989年   12篇
  1988年   15篇
  1987年   14篇
  1986年   16篇
  1985年   20篇
  1984年   14篇
  1983年   2篇
  1982年   14篇
  1981年   12篇
  1980年   13篇
  1979年   15篇
  1978年   6篇
  1977年   6篇
  1976年   17篇
  1974年   5篇
  1973年   1篇
排序方式: 共有1831条查询结果,搜索用时 15 毫秒
1.
《Physics letters. A》2020,384(35):126904
Exploring the evolution of cooperation has been one of the most challenging topics and attracted increasing attention in various realms. Hereby, we institute an analytic model where the relationship between the common benefits and contributions is the typical saturation nonlinearity. We investigate the evolutionary dynamics of cooperation with and without consensual incentives respectively. The population always evolves to full defection when the incentives are absent. Cooperation, however, can be promoted by consensual incentives when the degree of cooperators' preferences for incentives is great. There exists an intermediate amount of resources at which the positive effect of consensual incentives on cooperation is minimized. Furthermore, there is a U-shape relationship between the degree of cooperators' preference for an incentive and the evolution of cooperation. A greater basin of full cooperation can be induced when the cooperators' preference for reward is more pronounced than that for punishment.  相似文献   
2.
The method of equivalent variational methods, originally due to Carathéodory for free problems in the calculus of variations is extended to investigate feedback Nash equilibria for a class of n-person differential games. Both the finite-horizon and infinite-horizon cases are considered. Examples are given to illustrate the presented results.  相似文献   
3.
合作联盟资源集成计划一种新方法   总被引:1,自引:0,他引:1  
合作联盟里,资源集成计划往往是联盟成员群体谈判博弈的结果。本以两人博弈为例,对联盟的资源集成计划给出一个谈判博弈模型,能够较好地模仿和反映合作联盟资源整合计划的制订过程。  相似文献   
4.
基于CSCW的协同编著系统的设计   总被引:3,自引:0,他引:3  
讨论了计算机支持的协同工作(CSCW)的主要技术,其中重点讨论了协同编著系统设计中的并发控制技术,指出了其与传统的并发控制技术的区别。根据CSCW的基本原理设计出了一个基于Browse/Server结构的协同编著系统的系统模型。该系统模型比传统的模型更加方便了用户之间通过Internet的浏览器进行协作。  相似文献   
5.
Differential game formulations provide an adequate basis for a guidance law synthesis against highly maneuvering targets. This paper deals with a guidance law based on a linear-quadratic differential game formulation. This guidance law has many attractive properties: it is continuous, linear with respect to the state variables, and its gain coefficients can be precalculated offline. Nevertheless, due to the lack of hard control constraints in the formulation, the magnitude of the control can exceed the admissible level imposed by the nature of the problem. In this paper, the upper bound of the interceptor control is obtained depending on the system parameters and the penalty coefficients of the game performance index. It is shown that the interceptor can guarantee an arbitrarily small miss distance without exceeding the control constraints if it has sufficient maneuverability and if the penalty coefficients are chosen properly. By manipulating the penalty coefficients, it is possible to reduce significantly the maneuverability requirements compared to the case of zero interceptor penalty coefficient.  相似文献   
6.
Defining speed of diffusion as the amount of time it takes to get from one penetration level to a higher one, we introduce a dynamic model in which we study the link between pricing policy, speed of diffusion, and number of competitors in the market. Our analysis shows that, in the case of strategic (oligopolistic) competition, the speed of diffusion has an important influence on the optimal pricing policy. In particular, we find that higher speeds of diffusion create an incentive to strategically interacting firms to lower their prices.  相似文献   
7.
8.
A partnership in a cooperative game is a coalition that possesses an internal structure and, simultaneously, behaves as an individual member. Forming partnerships leads to a modification of the original game which differs from the quotient game that arises when one or more coalitions are actually formed. In this paper, the Shapley value is used to discuss the convenience to form either coalitions or partnerships. To this end, the difference between the additive Shapley value of the partnership in the partnership game and the Shapley alliance value of the coalition, and also between the corresponding value of the internal and external players, are analysed. Simple games are especially considered. Research partially supported by Grant BFM 2003-01314 of the Science and Technology Spanish Ministry and the European Regional Development Fund.  相似文献   
9.
本文提出了一类特殊的n人合作对策模型─—弱1—凸对策,研究了弱1—凸对策的解的性质,并证明弱1—凸对策的解满足所有常见的公理化特征.  相似文献   
10.
Noncooperative games of a finite number of persons with interval-valued payoff functions are considered. The concept of an equilibrium situation is introduced. A reduction of such games to deterministic noncooperative games is proposed. Properties of the reduced games are discussed. Interval antagonistic and bimatrix games are examined, and illustrative examples are considered.  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