方程: [数学] equation 短语和例子三次方程 cubic equation; 高次方程 equation of higher degree; 线性方程 linear equation; 把方程式简化成 ... reduce the equation to ...; 物态方程 equation of state; 化学方程 chemical equation
扩散方程: diffusion equationdiffusivity equationequation of deffusioonequation of diffusion