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   538篇
  免费   33篇
  国内免费   85篇
化学   11篇
力学   53篇
综合类   18篇
数学   539篇
物理学   35篇
  2023年   6篇
  2022年   4篇
  2021年   2篇
  2020年   6篇
  2019年   7篇
  2018年   9篇
  2017年   12篇
  2016年   16篇
  2015年   12篇
  2014年   18篇
  2013年   21篇
  2012年   16篇
  2011年   29篇
  2010年   23篇
  2009年   39篇
  2008年   47篇
  2007年   42篇
  2006年   29篇
  2005年   33篇
  2004年   33篇
  2003年   40篇
  2002年   27篇
  2001年   20篇
  2000年   28篇
  1999年   28篇
  1998年   12篇
  1997年   17篇
  1996年   13篇
  1995年   8篇
  1994年   20篇
  1993年   1篇
  1992年   4篇
  1991年   6篇
  1990年   5篇
  1988年   2篇
  1987年   1篇
  1986年   1篇
  1985年   2篇
  1984年   3篇
  1983年   1篇
  1982年   3篇
  1981年   2篇
  1980年   1篇
  1979年   3篇
  1978年   2篇
  1975年   1篇
  1972年   1篇
排序方式: 共有656条查询结果,搜索用时 15 毫秒
1.
In this paper,we will establish several strong convergence theorems for the approximation ofcommon fixed points of r-strictly asymptotically pseudocontractive mappings in uniformly convex Banachspaces using the modiied implicit iteration sequence with errors,and prove the necessary and sufficient conditionsfor the convergence of the sequence.Our results generalize,extend and improve the recent work,in thistopic.  相似文献   
2.
In this paper, we give some evaluation formulas for Tornheim's type of alternating series by an elementary and combinatorial calculation of the uniformly convergent series. Indeed, we list several formulas for them by means of Riemann's zeta values at positive integers.

  相似文献   

3.
By means of further investigation of solid codes,the problem“Is every fd-domain uni- formly dense”proposed by Yuqi Guo,C.M.Reis and G.Thierrin in 1988 is solved in this paper.  相似文献   
4.
用传统的预测效度估计法估计高考预测效度,其估计值往往偏低。为此,本文应用回归分析中混合估计理论提出了高考预测效度的混合估计。这种估计是预测效度的无偏估计,并解决了预测效度估计值偏低的问题。  相似文献   
5.
The present paper establishes sufficient conditions for the uniformly bounded of any solution of (1.1) and which tend to zero as t → ∞.  相似文献   
6.
共轴均匀带电薄圆盘间的相互作用力   总被引:3,自引:0,他引:3  
本文利用静电场的高斯定律和环路定律巧妙地求出了均匀带电圆盘在空间任一点所产生的电场 ,进而计算出了共轴均匀带电薄圆盘之间的相互作用力  相似文献   
7.
含k-次增生算子的Ishikawa迭代的收敛性问题   总被引:9,自引:0,他引:9  
主要研究了非线性方程x Tx=f的Ishikawa迭代解.其中T为k-次增生的或增生的,并在一致光滑和任意的实Banach空间分别研究了上述方程的带误差的Ishikawa迭代解,从而推广了已知的一些结果。  相似文献   
8.
Let (E, ¦·¦) be a uniformly convex Banach space with the modulus of uniform convexity of power type. Let be the convolution of the distribution of a random series inE with independent one-dimensional components and an arbitrary probability measure onE. Under some assumptions about the components and the smoothness of the norm we show that there exists a constant such that |{·<t}–{·+r<t}|r q , whereq depends on the properties of the norm. We specify it in the case ofL spaces, >1.  相似文献   
9.
We give a necessary and sufficient condition for the uniformly non-l n (1) property of Musielak-Orlicz sequence spacesl Φ generated by a sequence Φ=(ϕn:n⩾l) of finite Orlicz functions such that for eachn∈ℕ. As a result, forn 0⩾2, there exist spacesl Φ which are only uniformly non-l n (1) fornn 0. Moreover we obtain a characterization of uniformly non-l n (1) and reflexive Orlicz sequence spaces over a wide class of purely atomic measures and of uniformly non-l n (1) Nakano sequence spaces. This extends a result of Luxemburg in [19]. Submitted in memory of Professor W. Orlicz  相似文献   
10.
Properties of the random search in global optimization   总被引:3,自引:0,他引:3  
From theorems which we prove about the behavior of gaps in a set ofN uniformly random points on the interval [0, 1], we determine properties of the random search procedure in one-dimensional global optimization. In particular, we show that the uniform grid search is better than the random search when the optimum is chosen using the deterministic strategy, that a significant proportion of large gaps are contained in the uniformly random search, and that the error in the determination of the point at which the optimum occurs, assuming that it is unique, will on the average be twice as large using the uniformly random search compared with the uniform grid. In addition, some of the properties of the largest gap are verified numerically, and some extensions to higher dimensions are discussed. The latter show that not all of the conclusions derived concerning the inadequacies of the one-dimensional random search extend to higher dimensions, and thaton average the random search is better than the uniform grid for dimensions greater than 6.This paper is based on work started in the Statistics Department of Princeton University when the first author was visiting as a Research Associate. Part of this research was supported by the Office of Naval Research, Contract No. 0014-67-A-0151-0017, and by the US Army Research Office—Durham, Contract No. DA-31-124-ARO-D-215.2 The authors wish to thank B. Omodei for his careful work in preparing the programs for the results of Figs. 1–2 and Table 1. The computations were performed on the IBM 360/50 of the Australian National University's Computer Centre. Thanks are also due to R. Miles for suggestions regarding the extension of the results to multidimensional regions, and to P. A. P. Moran and R. Brent for suggestions regarding the evaluation of the integral 0 1 ... 0/1 (x 1 2 + ... +x n /2 )1/2 dx 1 ...dx n.  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