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   898篇
  免费   11篇
  国内免费   41篇
化学   17篇
力学   23篇
综合类   1篇
数学   850篇
物理学   59篇
  2023年   10篇
  2022年   17篇
  2021年   16篇
  2020年   17篇
  2019年   22篇
  2018年   18篇
  2017年   14篇
  2016年   14篇
  2015年   13篇
  2014年   35篇
  2013年   138篇
  2012年   28篇
  2011年   49篇
  2010年   43篇
  2009年   84篇
  2008年   70篇
  2007年   59篇
  2006年   48篇
  2005年   24篇
  2004年   27篇
  2003年   24篇
  2002年   15篇
  2001年   13篇
  2000年   13篇
  1999年   17篇
  1998年   21篇
  1997年   23篇
  1996年   18篇
  1995年   17篇
  1994年   8篇
  1993年   8篇
  1992年   2篇
  1991年   2篇
  1990年   4篇
  1989年   1篇
  1987年   2篇
  1985年   4篇
  1984年   4篇
  1983年   2篇
  1982年   2篇
  1981年   2篇
  1980年   1篇
  1979年   1篇
排序方式: 共有950条查询结果,搜索用时 187 毫秒
911.
912.
This paper presents a numerical method for the approximate solution of mth-order linear delay difference equations with variable coefficients under the mixed conditions in terms of Laguerre polynomials. The aim of this article is to present an efficient numerical procedure for solving mth-order linear delay difference equations with variable coefficients. Our method depends mainly on a Laguerre series expansion approach. This method transforms linear delay difference equations and the given conditions into matrix equation which corresponds to a system of linear algebraic equation. The reliability and efficiency of the proposed scheme are demonstrated by some numerical experiments and performed on the computer algebraic system Maple.  相似文献   
913.
In this article, we have established a relationship between a quadratic polynomial differential system and a Bernoulli equation by using the method of reflective function. And applied the results to discuss the qualitative behavior of solutions of this quadratic polynomial differential system.  相似文献   
914.
Consider an m-machine production line for processing identical parts served by a mobile robot. The problem is to find the minimum cycle time for 2-cyclic schedules, in which exactly two parts enter and two parts leave the production line during each cycle. This work treats a special case of the 2-cyclic robot scheduling problem when the robot route is given and the operation durations are to be chosen from prescribed intervals. The problem was previously proved to be polynomially solvable in O(m8log m) time. This paper proposes an improved algorithm with reduced complexity O(m4).  相似文献   
915.
In this paper we study the convergence of the famous Weierstrass method for simultaneous approximation of polynomial zeros over a complete normed field. We present a new semilocal convergence theorem for the Weierstrass method under a new type of initial conditions. Our result is obtained by combining ideas of Weierstrass (1891) and Proinov (2010). A priori and a posteriori error estimates are also provided under the new initial conditions.  相似文献   
916.
917.
Computable analysis is an extension of classical discrete computability by enhancing the normal Turing machine model. It investigates mathematical analysis from the computability perspective. Though it is well developed on the computability level, it is still under developed on the complexity perspective, that is, when bounding the available computational resources. Recently Kawamura and Cook developed a framework to define the computational complexity of operators arising in analysis. Our goal is to understand the effects of complexity restrictions on the analytical properties of the operator. We focus on the case of norms over C[0, 1] and introduce the notion of dependence of a norm on a point and relate it to the query complexity of the norm. We show that the dependence of almost every point is of the order of the query complexity of the norm. A norm with small complexity depends on a few points but, as compensation, highly depends on them. We briefly show how to obtain similar results for non-deterministic time complexity. We characterize the functionals that are computable using one oracle call only and discuss the uniformity of that characterization.  相似文献   
918.
Sharp Riesz–Bernstein-type inequalities are proven for the derivatives of algebraic polynomials on general subsets of unit circle. The sharp Riesz–Bernstein constant involves the equilibrium density of the set in question.  相似文献   
919.
In this work we suggest a systematic method of construction of solutions of the n-order Riccati equation with constant coefficients in a field from the set of generalized trigonometric functions. The generalized trigonometric functions satisfy the system of evolution equations generated by the companion matrix of n  -order polynomial. The set of trigonometric functions depend of (n−1)(n1) variables formally expressed by series of exponential functions. In a particular case, the second order Riccati equation with constant coefficients is isomorphic to the evolution equation generated by the companion matrix of the associated quadratic polynomial. It is shown that the n>2n>2 order Riccati equation with coefficients in a field is derived from a linear system of evolution equations generated by companion matrix of the associated n  -order polynomial under (n−2)(n2) constraints.  相似文献   
920.
In this paper we introduce and study the notion of homogeneous Tauberian polynomial, aiming at extending the concept of Tauberian operator. Such notion is characterized in terms of the polynomial topology for which we prove a Banach–Alaoglu type theorem. A number of examples show that the behavior of Tauberian polynomials differs from that of Tauberian operators.  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