Illuminance level on a surface . the hydraulic equivalent is represented by the amount of water falling onto the surface in question , within the time unit 重要?何?推? , ?照度的定? ?得, ?是很有用的可以去了解光在空?中的?散情形。
Illuminance level on a surface . the hydraulic equivalent is represented by the amount of water falling onto the surface in question , within the time unit 两个重要几何学推论,从照度的定义获得,这是很有用的可以去了解光在空间中的发散情形。