Chapter 29 Maxwell,s Equations and Electromagnetic Waves ◆ the density of displacement current(位移电流 密度) aD at displacement current C ad dyp ds Js at 通过电场中某一截面的位移电流等于通过该截面 电位移通量对时间的变化率 全电流、=l。+JaChapter 29 Maxwell’s Equations and Electromagnetic Waves t D j   =   d the density of displacement current (位移电流 密度 ) displacement current t Ψ s t D I j s S S d d d d d d =   =  =       通过电场中某一截面的位移电流等于通过该截面 电位移通量对时间的变化率. + + + + + - - - - - d I c I 全电流 s c d I = I + I