第十三章电磁感应电磁场 一、自感电动势自感 穿过闭合电流回路的磁通量

一、家用吸尘器的结构、工作原理及控制电路分析 二、抽油烟机的结构、工作原理 三、吸尘器的拆装与检修实训 四、抽油烟机的拆装与检修实训

光线轨迹:限制在子午平面内传播的周期曲线。轨迹曲线在 光纤端面投影线仍是过园心的直线,但一般不与纤壁相交。 广义折射定律:m(r)cos0(r)=K常数) 局部数值孔径:定义局部数值孔径NA(r)为入射点媒质折射率 与该点最大入射角的正弦值之积,即

What is FBG? An in-fibre Bragg grating is constructed by varying the refractive index of the core lengthwise along the fibre. Light of the specified wavelength traveling along the fibre is reflected from the grating back in the direction from which it came. Wavelengths which are not selected are passed through with little or no attenuation

经典力学在伽利略变换下形式不变(具有伽利略 协变性),一般仅适用于v<