implicit difference approximation的用法和樣例：
例句
- In a Cartesian coordinate system, we carry out a finite difference analysis of a general form of the energy equation.
在直角坐標系中，對能量本徵方程的一般形式進行有限差分解析，並建立相應的差分格式。 - Based on this method, a difference scheme is derived for the numerical solution of diffusion equation on the structured quadrilateral mesh.
在此基礎上推導了在結構四邊形網格上求解擴散方程的線性精確差分格式。
