Abstract: A stable dispersant and an application thereof in preparing copolymer polyols, the preparation method for the stable dispersant including the steps of 1) contacting a polyol with a dianhydride compound for reaction so as to prepare an adduct; 2) performing a ring-opening addition reaction on the adduct obtained in step 1) and an epoxy compound to prepare a stable dispersant; the dianhydride compound does not contain a double bond that may copolymerize with an olefinically unsaturated monomer, while the epoxy compound contains a double bond that may copolymerize with an olefinically unsaturated monomer, the polyol is a polyester polyol and/or a polyether polyol, preferably being a polyether polyol. The stable dispersant obtained by means of the described preparation method has a multi-active site anchoring function, and is applied to the synthesis of copolymer polyols to obtain copolymer polyols having relatively uniform particle size.

Abstract: The present invention relates to the technical field of electronic music instruments, and provides an electronic cymbal which comprises a support piece and a cymbal body made of a soft elastic material. A through hole is disposed in the center of the cymbal body. A connection portion for connecting the cymbal body is disposed at an upper end of the support piece. The connection portion comprises a head portion and a support rod portion which are disposed from top down and integrally formed with the support piece. A size of an outer diameter of the support rod portion is less than sizes of outer diameters of the head portion and the support piece, and a limiting step is formed at a lower end of the support rod portion. The disclosed electronic cymbal provides a better beat feel, simple structure and ease of mounting.