differentiall operator的用法和样例：
例句
- The Hamiltonian of the system is the Driac operator which as a matrix differential operator is not semibounded from below.
系统的哈密顿函数是作为矩阵微分算子的狄拉克算子，它不是半有界的。 - 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。
