2results about How to "Increase surface charge" patented technology

This application relates to the field of metal powder preparation technology, and in particular to a method for preparing silver powder for ultrafine line printing, comprising the following steps: preparing a silver ammonia solution and adding a dispersant, stirring to dissolve, adding a reducing agent solution, and aging to obtain nano-silver sol; forming a mixture of an initiator and deionized water, preparing aqueous solutions of acrylic acid and acrylamide separately, and adding them to the mixture for reaction, cooling and filtering to obtain an acrylic acid-acrylamide copolymer; weighing silver nitrate and deionized water, stirring to obtain solution A; weighing a reducing agent and deionized water, adjusting the pH to 1-2, and then adding the nano-silver sol and acrylic acid-acrylamide copolymer to obtain solution B; rapidly adding solution A to solution B, adding a surface modifier after the reaction is complete, aging, centrifuging, washing, and drying. The silver powder prepared by this application has the advantages of small average particle size, good overall uniformity, and small surface area, making it suitable for the field of ultrafine line printing.

The invention discloses a horseradish peroxidase mutant with improved thermal stability and construction and application of genetically engineered bacteria of the horseradish peroxidase mutant, and belongs to the technical field of biology. The horse radish peroxidase mutant capable of efficiently catalyzing oxidation reaction of various organic and inorganic substrates is constructed, compared with wild type HRP, the half-life period of the mutant at the temperature of 50 DEG C is prolonged, and the half-life period of double mutants can be prolonged to 4 times that of the wild type HRP. The horse radish peroxidase variant disclosed by the invention has a wide application prospect, particularly shows excellent catalytic efficiency and stability under harsh reaction conditions, and provides a better enzyme tool for the fields of industry and biomedicine.