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   1180篇
  免费   1篇
  国内免费   14篇
化学   421篇
晶体学   1篇
力学   46篇
数学   313篇
物理学   414篇
  2018年   9篇
  2014年   13篇
  2013年   35篇
  2012年   30篇
  2011年   33篇
  2010年   35篇
  2009年   17篇
  2008年   40篇
  2007年   27篇
  2006年   39篇
  2005年   29篇
  2004年   31篇
  2003年   25篇
  2002年   32篇
  2001年   25篇
  2000年   24篇
  1999年   23篇
  1998年   21篇
  1997年   14篇
  1996年   25篇
  1995年   24篇
  1994年   27篇
  1993年   39篇
  1992年   29篇
  1991年   20篇
  1990年   29篇
  1989年   26篇
  1988年   22篇
  1987年   17篇
  1986年   21篇
  1985年   30篇
  1984年   19篇
  1983年   13篇
  1982年   26篇
  1981年   23篇
  1980年   13篇
  1979年   26篇
  1978年   21篇
  1977年   17篇
  1976年   26篇
  1975年   22篇
  1974年   16篇
  1973年   18篇
  1972年   19篇
  1971年   15篇
  1970年   19篇
  1969年   18篇
  1968年   13篇
  1967年   11篇
  1966年   9篇
排序方式: 共有1195条查询结果,搜索用时 31 毫秒
101.
The total hadron multiplicity and the multiplicity in the three-jet events ine + e ?-annihilation are considered. The formula for the total multiplicity (with account for the heavy quark contribution) agrees well with experiment. The value of the multiplicity for three-jet events is predicted.  相似文献   
102.
103.
104.
105.
106.
On differential stability in stochastic programming   总被引:2,自引:0,他引:2  
In this paper optimal solutions of a stochastic programming problem are considered as functions of the underlying probability distribution. Their directional derivatives, in the sense of Gâteaux, are calculated by applying some recent results from the sensitivity analysis of nonlinear programs. These derivatives are employed as a heuristic device in order to derive the asymptotic distribution of statistical estimators of the optimal solutions.  相似文献   
107.
The vast size of real world stochastic programming instances requires sampling to make them practically solvable. In this paper we extend the understanding of how sampling affects the solution quality of multistage stochastic programming problems. We present a new heuristic for determining good feasible solutions for a multistage decision problem. For power and log-utility functions we address the question of how tree structures, number of stages, number of outcomes and number of assets affect the solution quality. We also present a new method for evaluating the quality of first stage decisions.  相似文献   
108.
The electrochemical activity of a suspension of human erythrocytes was found at potentials above +0.4 V. The limiting current of electrooxidation was found to linearly depend on the cell concentration in the suspension. The electrochemical activity of an erythrocyte suspension is accompanied by reversible changes in the cell morphology only in non-buffered media.  相似文献   
109.
An asymptotic model of the flow in the laminar boundary layer of a gas-evaporating droplet mixture is constructed within the framework of the two-continuum approximation. The case of evaporation of the droplets into an atmosphere of their own vapor is examined in detail with reference to the example of longitudinal flow over a hot flat plate. Numerical and asymptotic solutions of the boundary layer equations constructed are found for a number of limiting situations (low droplet concentration, no droplet deposition, significant droplet deposition). The development of the flow with respect to the longitudinal coordinate is studied and it is shown that in the absence of droplet deposition a region of pure vapor may be formed near the surface. Similarity criteria are established and the mechanism of surface heat transfer enhancement is studied for a low evaporating droplet concentration in the boundary layer. In the inertial deposition regime the results of calculating the integral heat transfer coefficient are found to correspond with the experimental data [1].Translated from Izvestiya Rossiiskoi Akademii Nauk, Mekhanika Zhidkosti i Gaza, No.3, pp. 42–50, May–June, 1992.  相似文献   
110.
The block mechanism of the formation of J-aggregates from the dimers of various dyes in an aqueous solution under the action of the multiply charged Eu+3 cation was considered for the first time. It was shown that the structure and the position of the absorption maximum of the mixed J-aggregates are determined by the length of the dye chromophore moiety. It was concluded that the mixed J-aggregates are of interest as nanosized optical elements with varying optical and electronic properties depending on the structure of cyanines used.  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