Al原子共振双线跃迁几率实验研究

我们用Nd：YAG脉冲激光烧蚀金属Al靶产生等离子体，利用时间分辨技术摄取Al等离子体辐射时间分辨谱，获得Al原子共振双线辐射谱；通过积分谱线下的面积，计算共振双线强度；根据共振双线强度比，推断Al原子共振双线跃迁几率比，并与理论计算结果比较。结果发现，实验结果与理论计算符合的很好。     

北京谱仪桶部簇射计数器能量响应特性研究

在北京正负电子对撞机的J/ψ和Ds能区,选择了辐射巴巴事例,并以此来研究北京谱仪的桶部簇射计数器能量响应特性.在消除了由于电子和辐射光子在桶部簇射计数器中沉积能量区域重叠的影响后,正确地得到了桶部簇射计数器在电子和光子动量小于2GeV以下的能量响应,表明在所研究能区,桶部簇射计数器的能量响应线性很好.对桶部簇射计数器微小的非线性进行修正后,重建的π0不变质量谱得到改善.     

Geometric Formulation of Gauge Theory of Gravity

DitTerential geometric formulation of quantum gauge theory of gravity is studied in this paper. The quantum gauge theory of gravity is formulated completely in the framework of traditional quantum field theory. In order to study the relationship between quantum gauge theory of gravity and traditional quantum gravity which is formulated in curved space, it is important to set up the geometry picture of quantum gauge theory of gravity. The correspondence between quantum gauge theory of gravity and differential geometry is discussed and the geometry picture of quantum gauge theory of gravity is studied.     

弱于H~1空间的L~2-临界非线性Schrdinger方程的柯西问题

讨论H~s(R~n)(n≥1,1-ε0是一个可以表出的很小的数.主要结论给出了在有限时间破裂解的L~2集中现象.同时,作为推论,得到了小初值解的整体存在性.     

混沌时间序列基于邻域点的非线性多步自适应预测

根据流形理论，利用混沌时间序列中某点邻域内最近几点的P次迭代像，提出了一种多步自 适应预测算法.仿真说明，这种算法使得预测速度成倍提高，而预测稳定后得到的误差均方 根序列呈指数增长趋势，这个指数就是该混沌时间序列的Lyapunov指数. 关键词： 混沌时间序列 邻域 非线性自适应预测 Lyapunov指数     

ON THE PARTIAL EQUIASYMPTOTIC STABILITY OF NONLINEAR TIME-VARYING DIFFERENTIAL EQUATIONS

In this paper, the problem of partial equiasymptotic stability for nonlinear time-varying differential equations are analyzed. A sufficient condition of partial stability and a set of sufficient conditions of partial equiasymptotic stability are given. Some of these conditions allow the derivative of Lyapunov function to be positive. Finally, several numerical examples are also given to illustrate the main results.     

多道时间谱仪测量光速

介绍了多道时间谱仪的时间幅度变换原理，描述了谱仪的调试和主要指标的测定，并应用多道时间谱仪测量了光速．     

IMPLICIT DIFFERENCE APPROXIMATION FOR A TIME FRACTIONAL ADVECTION-DISPERSION EQUATION

In this paper, a time fractional advection-dispersion equation is considered. From the relationship between the Caputo derivative and the Grunwald derivative, the Caputo derivative is approximated by using the Griinwald derivative. An implicit difference approximation for this equation is proposed. We prove that this approximation is unconditionally stable and convergent. Finally, numerical examples are given.     

方兴未艾的磁致电阻研究

 我们知道,在金属中散射作用是电阻产生的主要原因,这包括杂质散射和晶格热运动引起的电声子互作用。根据动量定理,电子在时间间隔△t内受到电场E的作用而产生的定向漂移速度.     

浅谈空盘除法

空盘乘法由于被乘数和乘数都不拨在算盘上面。可以减少拨被乘数和乘数的时间，从而提高计算速度，深受人们欢迎，现已广泛普及使用。可是，空盘除法人们使用者甚少，因为人们一提到除法，就觉得很难，而且计算速度不快，空盘除法就不堪设想，可谓是难上加难。其实，空盘除法只要掌握其运算方法和技巧，也并不很难，同时，也是提高除法计算速度的一种切实可行的好方法。