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   4214篇
  免费   414篇
  国内免费   274篇
化学   270篇
晶体学   1篇
力学   189篇
综合类   140篇
数学   3848篇
物理学   454篇
  2024年   5篇
  2023年   28篇
  2022年   85篇
  2021年   110篇
  2020年   75篇
  2019年   81篇
  2018年   75篇
  2017年   136篇
  2016年   179篇
  2015年   108篇
  2014年   252篇
  2013年   263篇
  2012年   201篇
  2011年   214篇
  2010年   195篇
  2009年   274篇
  2008年   292篇
  2007年   250篇
  2006年   238篇
  2005年   236篇
  2004年   172篇
  2003年   187篇
  2002年   155篇
  2001年   130篇
  2000年   119篇
  1999年   103篇
  1998年   119篇
  1997年   86篇
  1996年   80篇
  1995年   51篇
  1994年   39篇
  1993年   36篇
  1992年   40篇
  1991年   24篇
  1990年   20篇
  1989年   27篇
  1988年   23篇
  1987年   6篇
  1986年   8篇
  1985年   43篇
  1984年   24篇
  1983年   12篇
  1982年   19篇
  1981年   19篇
  1980年   22篇
  1979年   17篇
  1978年   9篇
  1977年   5篇
  1976年   4篇
  1959年   2篇
排序方式: 共有4902条查询结果,搜索用时 15 毫秒
31.
Goguadze  D. F. 《Mathematical Notes》2003,74(3-4):346-351
We introduce a generalized notion of semiring and prove that all known properties that semirings have according to the old definition are preserved.  相似文献   
32.
Systems that involve more than one decision maker are often optimized using the theory of games. In the traditional game theory, it is assumed that each player has a well-defined quantitative utility function over a set of the player decision space. Each player attempts to maximize/minimize his/her own expected utility and each is assumed to know the extensive game in full. At present, it cannot be claimed that the first assumption has been shown to be true in a wide variety of situations involving complex problems in economics, engineering, social and political sciences due to the difficulty inherent in defining an adequate utility function for each player in these types of problems. On the other hand, in many of such complex problems, each player has a heuristic knowledge of the desires of the other players and a heuristic knowledge of the control choices that they will make in order to meet their ends.In this paper, we utilize fuzzy set theory in order to incorporate the players' heuristic knowledge of decision making into the framework of conventional game theory or ordinal game theory. We define a new approach to N-person static fuzzy noncooperative games and develop a solution concept such as Nash for these types of games. We show that this general formulation of fuzzy noncooperative games can be applied to solve multidecision-making problems where no objective function is specified. The computational procedure is illustrated via application to a multiagent optimization problem dealing with the design and operation of future military operations.  相似文献   
33.
Noninferior Nash Strategies for Multi-Team Systems   总被引:1,自引:0,他引:1  
This paper is concerned with the optimization of systems that are controlled by several teams of decision makers. The decision makers within each team cooperate for the benefit of their team. On the other hand, the teams compete among themselves in order to achieve an objective that relates to the overall performance of the system. An approach that merges concepts from team theory and game theory for dealing with such systems and a solution called the noninferior Nash strategy are introduced. This multi-team solution provides a new framework for analyzing hierarchically controlled systems so as to address complicated coordination problems among the decision makers. The properties of the noninferior Nash solution in static multi-team systems are investigated and necessary conditions for its existence are derived. Analytical expressions for the noninferior Nash strategies are derived for a class of linear-quadratic static multi-team games. In order to deal with the issue of nonuniqueness of the solution, the concept of a noninferior Nash strategy with a team leader is introduced. Several examples are presented to illustrate the results.  相似文献   
34.
In this paper, we suggest and analyze some iterative methods for solving nonconvex variational inequalities using the auxiliary principle technique, the convergence of which requires either only pseudomonotonicity or partially relaxed strong monotonicity. Our proofs of convergence are very simple. As special cases, we obtain earlier results for solving general variational inequalities involving convex sets.  相似文献   
35.
In this article we prove a strong law of large numbers for Borel measurable nonseparably valued random elements in the case of generalized random sets.

  相似文献   

36.
ANTIFUZZYVECTORSPACES(Ⅱ)ChenYongnian(DepartmentofMathematics,XinjiangNormalUniversity,830054,Xinjiang,P.R.China)ANTIFUZZYVECT...  相似文献   
37.
Existence theorems of continuous selectors whose values are fixed points of multivalued contractions are proved. As an application, the existence of continuous selectors to generalized solution sets of partial differential inclusions, depending on a parameter, is obtained.  相似文献   
38.
关于E-凸函数及E-凸规划几个错误结论的修正   总被引:2,自引:0,他引:2  
覃义  简金宝 《数学杂志》2006,26(2):177-180
本文研究Youness在1999年建立的有关E凸函数和E规划的结论.利用E凸函数和E凸规划的基本性质和优化分析技术,获得了有关E凸函数E凸规划的几个错误结论的修正..  相似文献   
39.
An interval-parameter fuzzy linear programming method (IFMOLP) is proposed in this study for multiple objective decision-making under uncertainty. As a hybrid of interval-parameter and fuzzy methodologies, the IFMOLP incorporates interval-parameter linear programming and fuzzy multiobjective programming approaches to form an integrated optimization system. The method inherits advantages of interval-parameter programming, and allows uncertainties and decision-makers’ aspirations to be effectively communicated into its programming processes and resulting solutions. Membership functions for both objectives and constraints are formulated to reflect uncertainties in different system components and their interrelationships. An interactive solution procedure has been developed based on solution approaches of the interval-parameter and fuzzy programming techniques, plus necessary measures for handling the multiobjective feature. A didactic example is provided in the paper to illustrate the detailed solution process. Possibilities of further improvements by seeking Pareto optimum and incorporating flexible preference within constraints are also discussed.  相似文献   
40.
研究(QU)型模糊拓扑群族直积,证明了任意(QU)型模糊拓扑群族的直积仍是(QU)型模糊拓扑群;研究了(QU)型模糊拓扑群族直积的模糊单位元之重域基的结构,得到了(QU)型模糊拓扑群族直积的一些重要性质.  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