Abstract: A circuit breaker, comprising a housing, an operation assembly, an arc extinguishing device, and a transmission mechanism. The housing has, in a first direction, a bottom and a top opposite to each other, an accommodation portion recessed from the top to the bottom, and an accommodation cavity semi-surrounding the accommodation portion; a rotating wheel and a movable contact connected to the rotating wheel are provided in the accommodation cavity close to the top and adjacent to the accommodation portion in a second direction, wherein the first direction intersects the second direction; the operation assembly is rotatably and detachably connected to the top of the housing; the arc extinguishing device comprises an arc extinguishing chamber located in the accommodation cavity and close to the bottom of the housing. The circuit breaker can avoid interference between the transmission mechanism and other components while increasing the size of the arc extinguishing chamber.

Abstract: Disclosed is a polymerization inhibitor of N-vinyl pyrrolidone monomers and use thereof. The polymerization inhibitor is selected from an inorganic weak acid potassium salt and/or an organic acid potassium salt. The polymerization inhibitor is added to N-vinyl pyrrolidone monomers, and is sealed and preserved under the protection of inert gas, wherein the addition amount of the polymerization inhibitor is 0.005-0.2% by mass with respect to the mass of the N-vinyl pyrrolidone monomers. Directly adding the polymerization inhibitor into the N-vinyl pyrrolidone monomers in proportion can inhibit the self-polymerization of the N-vinyl pyrrolidone monomers, and hence extend the shelf life. The chromaticity and toxicity of the monomers can be reduced to a great extent. The polymerization inhibitor can be used directly during solution polymerization without being removed, and does not affect the chromaticity of a polymerization solution.