Chapter 20 Gauss s law 第八章静电场 3)For nonuniform fields and curved surfaces we rewrite this definition of electric flux in differential form. ◆非均匀电场强度电通量 dS=dS·en Eds E d④=EdS ④=|d④ E cos edS ①=E.dS (electric flux through a Gaussian surface)Chapter 20 Gauss’s Law 第八章静电场 3) For nonuniform fields and curved surfaces we rewrite this definition of electric flux in differential form: E 非均匀电场强度电通量      s Φ dΦ E cos dS e e     s Φ E S   d e Φ E S   d d e   d d n S S e     S  d E   n e  (electric flux through a Gaussian surface)