The standard parabolic equation method was obtained by the decompocition of the scalar wave equation and the expansion of the pseudo-differential operator. 通过对传统波动方程的分解和伪微分算子的近似展开，获得了标准抛物线方程。
So this method is effective in soluting two-dimensional parabolic equation and can be widely used. 该方法是求解二维抛物型方程的有效方法，必将得到更广泛的应用。
Part II, a parabolic initial boundary value problem in unbounded domains in three dimensions is studied. 第二部分，研究求解无界区域上三维抛物型方程初边值问题的数值方法。
