In 1818 Fresnel entered a competition sponsored by French Academy.1818年菲涅耳参加了法国科学院主办的一次竞赛.The difficulty was resolved by Fresnel with his addition of the concept of interference.菲涅耳通过加进来干涉概念,解决了这个困难.In many cases, the Si...

n.菲（涅耳）（频率单位，百亿赫兹），菲涅耳...

fresnel的音标：...