Analysis and Treatment for the Carbon Brush of Direct Current Exciter to Strike a Light on the Spot.
现场直流励磁机碳刷打火的分析与处理

The U. S. military always under the public spot light, especially the oversea military bases in Asia.
灯光总是聚在美国的军队，特别是美国在亚洲的军事基地。

The aberration and the distribution value of blur spot on the intersection point of the orientation of image were calculated by the light focus formula.
采用光线追迹公式计算球差量和像方交点弥散斑分布值。