最高阶导数 meaning in English

highest derivative

A quasilinear equation is one in which the highest-order derivative appears linearly .
最高阶导数线性地出现的那种方程是准线性方程。
At first , we took the kdv equation and the kdv - burgers equation as examples to point out the fact that it is not necessary to obtain the value of the order of solitary wave solutions by equating the highest nonlinear term and the highest - order partial derivative term in this method . meanwhile , we obtained some exact solitary wave solutions of the kdv - burgers equation
首先以kdv方程和kdv - burgers方程为例，指出在该方法中，孤立波解的阶数通过平衡非线性方程的非线性项和最高阶导数项得到是不必要的，同时也得到了kdv - burgers方程的两组精确解。