The five points difference method is used to calculate the voltage distribution on the meridian surface of axial-symmetrical electrostatic lens.

采用五点差分法计算轴对称静电透镜子午面上电位分布，再从普遍轨迹方程求得的电子轨迹出发得到透镜焦点和球差。

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Based on paraxial meridian-ray equation, the principle of fibre accelerometer using self-focussing lens is studied;

本文根据近轴子午光线方程，研究了自聚焦透镜光纤加速度计的工作原理；

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