Angular Distribution of Synchrotron Radiation in Low Frequency

The angular distribution of energy for synchrotron radiation in low frequency band （ω 〈〈 we） is obtained by rigorously solving the Nicolo Tartaglia equation. The result shows that the critical angle increases with decreasing frequency, but it cannot exceed 90°. The relation between critical angle θc. and frequency is common covering all wavelengths. For the small angle case, it is consistent with the result obtained by Jackson. With the increase of emanative angle, the radiant intensity increases first, then decays.     

小学生计算能力培养的策略探析

小学数学教育阶段,教师要根据具体的计算教学模式,从计算内容与教育方式的开发上进行优化,为学生提供便利的学习平台.本文从小学数学教学培养学生应用计算能力的现实意义出发,基于培养小学阶段计算能力的方法与途径,提出强化教学策略,提高教学效果;培育良好习惯,强化计算能力;强化计算效能,培养综合素质等优化教学策略.     

A Quasi—One—Dimensional Model for a Solar Flux Tube

We develop the quasi-one-dimensional flux tube model with magnetohydrodynamical equations.In order to know whether the magnetic field can maintain their similar structure from photosphere to chromosphere,we suppose that the flux tube is thin in radius relative to the length,and that the quantities in the cross section are averaged.The radii of the flux tube and the magnetic field are numerically simulated.One of the important results shows that the flux tube does not expand as quickly as the existing model when it is out of the photoxphere with high velocity.This is consistent with observations of the magnetic field in the photosphere and chromosphere.