Simple lens formula的意思|示意

By assuming the weak lens focal length expression to be the first term in a power series a simple and accurate formula can be derived for the objective focal length of a magnetic electron lens.

用假设弱透镜焦距表达式是一个幂级数中的第一项的方法，可以导出相当准确且便于实用的电磁电子透镜物镜焦距公式。

And give out the unified optical path, Newton's ring radius and convex lens curvature radius measurement formula of non - contact type, simple cutting type and tangent type Newton's Rring.

并给出了非接触式、浅近切割式及相切式牛顿环的统一的光程差，牛顿环半径及凸透镜曲率半径测量公式。