Abstract: A 6P lens suitable for small mounting hole, comprising an aperture stop, a first, second, third, fourth, fifth and sixth lens along the optical axis from the object side to the image side. An object surface of the first lens is convex, and changes from the convex surface to the concave surface, an image surface is concave, changes from the concave surface to the convex surface from the near optical axis to the periphery; An object surface of the second lens is convex and an image surface is concave; An object surface of the third lens is concave, an image surface is convex; An object surface of the fourth lens is concave, an image surface is convex; An object surface of the fifth lens is concave, an image surface is convex; An object surface of the sixth lens is a concave surface, and its image surface is convex.

Abstract: Disclosed is an electrolytic aluminum system based on a flexible DC (Direct Current) microgrid, by using the current adjustment and cloud monitoring transmission technology for electrolytic aluminum temperature electrochemical reaction elements.