特征重根型线性非齐次微分方程的求解

主要解决特征重根型的变系数线性非齐次微分方程的两个问题：其一，推广常系数线性非齐次方程的降阶原理；其二，该类方程可在预先不知道任何解的前提下求其方程的特解，也可求出通解．

Comprehensive Study on the Estimation of the Variance Components of Traverse Nets

This paper advances a new simplified formula for estimating variance components ,sums up the basic law to calculate the weights of observed values and a circulation method using the increaments of weights when estimating the variance components of traverse nets,advances the charicteristic roots method to estimate the variance components of traveres nets and presents a practical method to make two real and symmetric matrices two diagonal ones.