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   110篇
  免费   14篇
化学   82篇
力学   12篇
数学   23篇
物理学   7篇
  2023年   3篇
  2021年   4篇
  2020年   5篇
  2019年   2篇
  2018年   5篇
  2017年   3篇
  2016年   4篇
  2015年   10篇
  2014年   4篇
  2013年   8篇
  2012年   5篇
  2011年   7篇
  2010年   4篇
  2009年   3篇
  2008年   9篇
  2007年   2篇
  2006年   2篇
  2004年   2篇
  2003年   2篇
  2002年   1篇
  2001年   1篇
  1999年   1篇
  1997年   1篇
  1995年   1篇
  1992年   2篇
  1990年   1篇
  1989年   1篇
  1988年   2篇
  1987年   2篇
  1986年   3篇
  1983年   1篇
  1982年   3篇
  1980年   3篇
  1979年   1篇
  1978年   1篇
  1976年   2篇
  1975年   2篇
  1974年   1篇
  1969年   1篇
  1963年   1篇
  1962年   4篇
  1961年   1篇
  1960年   1篇
  1934年   1篇
  1923年   1篇
排序方式: 共有124条查询结果,搜索用时 0 毫秒
121.
In this paper, we show that the iterative method of Brown and Robinson, for solving a matrix game, is also applicable to a converging sequence of matrices, where the players choose at staget a row and a column of thet-th matrix in the sequence. As an application of this result, we describe a new solution method for discounted stochastic games with finite state and action spaces.  相似文献   
122.
One of the popular method for fitting a regression function is regularization: minimizing an objective function which enforces a roughness penalty in addition to coherence with the data. This is the case when formulating penalized likelihood regression for exponential families. Most of the smoothing methods employ quadratic penalties, leading to linear estimates, and are in general incapable of recovering discontinuities or other important attributes in the regression function. In contrast, non-linear estimates are generally more accurate. In this paper, we focus on non-parametric penalized likelihood regression methods using splines and a variety of non-quadratic penalties, pointing out common basic principles. We present an asymptotic analysis of convergence rates that justifies the approach. We report on a simulation study including comparisons between our method and some existing ones. We illustrate our approach with an application to Poisson non-parametric regression modeling of frequency counts of reported acquired immune deficiency syndrome (AIDS) cases in the UK.  相似文献   
123.
Bromination reaction of 2′-NHR-3,4′-methylenedioxychalcone (1) and 2,3-dihydro-2-(3′,4′-methylenedioxyphenyl)-4(1H)-quinolone (7) with bromine and N-bromosuccinimide are discussed. Depending on the character of the R group and on the reagent used nuclear or side-chain brominated or side-chain bromo-methoxylated products were obtained.  相似文献   
124.
Quantum mechanics dictates that nuclei must undergo some delocalization. In this work, emergence of quantum nuclear delocalization and its rovibrational fingerprints are discussed for the case of the van der Waals complex . The equilibrium structure of is planar and T-shaped, one He atom solvating the quasi-linear He−H+−He core. The dynamical structure of , in all of its bound states, is fundamentally different. As revealed by spatial distribution functions and nuclear densities, during the vibrations of the molecule the solvating He is not restricted to be in the plane defined by the instantaneously bent chomophore, but freely orbits the central proton, forming a three-dimensional torus around the chromophore. This quantum delocalization is observed for all vibrational states, the type of vibrational excitation being reflected in the topology of the nodal surfaces in the nuclear densities, showing, for example, that intramolecular bending involves excitation along the circumference of the torus.  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