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   1316篇
  免费   198篇
  国内免费   37篇
化学   16篇
力学   5篇
综合类   32篇
数学   1426篇
物理学   72篇
  2023年   9篇
  2022年   43篇
  2021年   59篇
  2020年   46篇
  2019年   54篇
  2018年   42篇
  2017年   59篇
  2016年   53篇
  2015年   42篇
  2014年   74篇
  2013年   145篇
  2012年   67篇
  2011年   84篇
  2010年   95篇
  2009年   81篇
  2008年   95篇
  2007年   106篇
  2006年   67篇
  2005年   44篇
  2004年   32篇
  2003年   44篇
  2002年   20篇
  2001年   24篇
  2000年   28篇
  1999年   23篇
  1998年   16篇
  1997年   12篇
  1996年   8篇
  1995年   11篇
  1994年   14篇
  1993年   4篇
  1992年   7篇
  1991年   6篇
  1990年   3篇
  1989年   2篇
  1988年   3篇
  1987年   3篇
  1986年   2篇
  1985年   6篇
  1984年   4篇
  1983年   2篇
  1982年   2篇
  1981年   4篇
  1980年   2篇
  1979年   1篇
  1977年   1篇
  1976年   1篇
  1959年   1篇
排序方式: 共有1551条查询结果,搜索用时 15 毫秒
1.
In this work, we suggest a novel quadratic programming‐based algorithm to generate an arbitrage‐free call option surface. The empirical performance of the proposed method is evaluated using S&P 500 Index call options. Our results indicate that the proposed method provides a more precise fit to observed option prices than other alternative methodologies. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   
2.
Aliprantis  C.D.  Cornet  B.  Tourky  R. 《Positivity》2002,6(3):205-241
Mathematical economics has a long history and covers many interdisciplinary areas between mathematics and economics. At its center lies the theory of market equilibrium. The purpose of this expository article is to introduce mathematicians to price decentralization in general equilibrium theory. In particular, it concentrates on the role of positivity in the theory of convex economic analysis and the role of normal cones in the theory of non-convex economies.  相似文献   
3.
股票价格遵循几何分式Brown运动的期权定价   总被引:6,自引:0,他引:6  
讨论了股票价格过程遵循几何分式B row n运动的欧式期权定价.由于该过程存在套利机会使得传统的期权定价方法(如资本资产定价模型(CAPM),套利定价模型(APT),动态均衡定价理论(DEPT))不可能对该期权定价.利用保险精算定价法,在对市场无其它任何假设条件下,获得了欧式期权的定价公式.并讨论了在有效期内股票支付已知红利和红利率的推广公式.  相似文献   
4.
Glazebrook  K.D.  Lumley  R.R.  Ansell  P.S. 《Queueing Systems》2003,45(2):81-111
We consider the optimal service control of a multiclass M/G/1 queueing system in which customers are served nonpreemptively and the system cost rate is additive across classes and increasing convex in the numbers present in each class. Following Whittle's approach to a class of restless bandit problems, we develop a Langrangian relaxation of the service control problem which serves to motivate the development of a class of index heuristics. The index for a particular customer class is characterised as a fair charge for service of that class. The paper develops these indices and reports an extensive numerical investigation which exhibits strong performance of the index heuristics for both discounted and average costs.  相似文献   
5.
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   
6.
7.
We develop a production policy that controls work-in-process (WIP) levels and satisfies demand in a multistage manufacturing system with significant uncertainty in yield, rework, and demand. The problem addressed in this paper is more general than those in the literature in three aspects: (i) multiple products are processed at multiple workstations, and the capacity of each workstation is limited and shared by multiple operations; (ii) the behavior of a production policy is investigated over an infinite-time horizon, and thus the system stability can be evaluated; (iii) the representation of yield and rework uncertainty is generalized. Generalizing both the system structure and the nature of uncertainty requires a new mathematical development in the theory of infinite-horizon stochastic dynamic programming. The theoretical contributions of this paper are the existence proofs of the optimal stationary control for a stochastic dynamic programming problem and the finite covariances of WIP and production levels under the general expression of uncertainty. We develop a simple and explicit sufficient condition that guarantees the existence of both the optimal stationary control and the system stability. We describe how a production policy can be constructed for the manufacturing system based on the propositions derived.  相似文献   
8.
本文从经济学的观点出发,利用对策论方法建立了审讯过程的数学模型,并由此研究了讯问人三种主要策略对审讯成功的效度。  相似文献   
9.
针对基于Web的图书馆管理系统资源访问控制的动态性问题,提出了一种基于角色的访问控制策略描述方案.通过对基于Web的图书馆管理系统访问控制管理影响因素和访问控制需求的分析,结合NIST基于角色的访问控制统一模型标准,构造了一种基于角色的访问控制元模型.并在这一元模型的基础上,提出了一种紧凑的基于角色的访问控制XML策略描述语言框架.结果表明该访问控制策略描述语言框架适合表述动态环境下对图书馆资源的访问策略,提高了基于Web的图书馆管理系统资源访问的安全性.  相似文献   
10.
This article studies the inshore-offshore fishery model with impulsive diffusion. The existence and global asymptotic stability of both the trivial periodic solution and the positive periodic solution are obtained. The complexity of this system is also analyzed. Moreover, the optimal harvesting policy are given for the inshore subpopulation, which includes the maximum sustainable yield and the corresponding harvesting effort.  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