8results about How to "No defects" patented technology

The utility model relates to the technical field of wastewater treatment equipment, in particular to a micro-filtration membrane end face pouring tool which comprises a glass fiber reinforced plastic container and a micro-filtration membrane pipe, certain spaces exist between the two ends of the micro-filtration membrane pipe and the two end faces of the glass fiber reinforced plastic container, and a first limiting assembly and a second limiting assembly are arranged in the spaces of the two ends of the micro-filtration membrane pipe respectively. The first limiting assembly comprises a first sealing plug and a fixed end cover plate, the first sealing plug penetrates through the fixed end cover plate, one end of the first sealing plug is matched with one end of the microfiltration membrane tube, and the other end of the first sealing plug is connected with the fixed end cover plate through a bolt; one end of the fixed end cover plate is matched with the other end of the microfiltration membrane tube, the other end of the fixed end cover plate is connected with the end cover through a bolt, hoops are arranged on the periphery of the joint of the fixed end cover plate and the glass fiber reinforced plastic container and the periphery of the joint of the end cover and the glass fiber reinforced plastic container, and the fixed end cover plate and the end cover are connected with the hoops. The membrane tube is uniformly fixed, and pouring liquid is prevented from flowing into the micro-filtration membrane tube or leaking out of the micro-filtration membrane tube.

The application relates to the field of advanced structural ceramics, and particularly discloses a gel injection molding method for preparing high-performance silicon nitride ceramics and a preparation method thereof. Raw materials include beta-SiN submicron powder 75 parts, YO submicron powder 8 parts, TiC submicron powder 5 parts, AlO superfine powder 5 parts, ZrO submicron powder 2 parts and wollastonite 5 parts in terms of mass ratio, a complex whisker regulator and an entry liquid are used, and ceramics are prepared through gel injection molding, dehydration, degreasing and gas pressure sintering. The grain morphology and interface combination are optimized through the whisker regulator, the slurry dispersion and the green body uniformity are improved through the entry liquid, and the product has a density greater than or equal to 99%, a Vickers hardness greater than or equal to 1700HV and a bending strength greater than or equal to 930MPa through 1700-1850 DEG C. gas pressure sintering, and the product has high density, high hardness, high toughness, wear resistance, corrosion resistance and long service life.

The invention provides a strain for producing L-isoleucine and a construction method and application of the strain. Pck genes of the strain are knocked out, ilvBN (G20D, I21D and I22F), ilvA (V140M, F383A), lysC (T311I), hom (G378I), thrB (A20G), ppc, aspB, thrC, asd and brnFE are over-expressed, and the strain is prepared through operons Psod-ilvBN (G20D, I21D and I22F)-ilvA (V140M, F383A)-Ptuf-thrA-thrB-thrC and Psod-ppc-aspB-Ptuf

This invention relates to a method for manufacturing high-surface-quality steel wire for chain pins, comprising the following steps: steel smelting → continuous casting → heating of continuously cast billets → billet preparation → flaw detection and grinding of intermediate billets → wire rod heating → high-pressure water descaling → annealing → pickling and phosphating → wire drawing → finished product. The method employs a two-stage forming process, with a high compression ratio in billet rolling, wire rod rolling, and wire drawing, which reduces the impact of defects in the raw material on the finished product. During billet rolling, flame cleaning is used to remove surface defects from the billet. Before wire rod rolling, the intermediate billet undergoes surface flaw detection and full grinding to ensure a defect-free surface. Eddy current testing and high-reduction-ratio wire drawing ensure the depth of surface defects in the steel wire, and the high-reduction-ratio drawing results in higher wire hardness, improving the cutting performance for pin processing. Finally, the steel wire used in pin production can control the single-sided grinding residue to within 0.03mm, significantly improving material yield and surface defect compliance. Simultaneously, the high wire hardness provides excellent cutting performance for pin processing.

The invention discloses a method for improving the growth quality of a PVT method silicon carbide single crystal. The method comprises the steps of raw material optimization, fine temperature regulation and control, precise air pressure management and control and seed crystal treatment. Wherein abnormity of the axial temperature gradient and the temperature fluctuation in the growth chamber can cause reduction of the crystal quality, and for fine regulation and control of the temperature, the axial temperature gradient and the temperature fluctuation are analyzed to obtain temperature parameters of the growth chamber, and the axial temperature gradient is analyzed to obtain a gradient characterization value; judging whether the axial temperature gradient is qualified or not according to the gradient characterization value; if the temperature gradient is qualified, analyzing the temperature fluctuation to obtain a fluctuation evaluation value; judging whether the temperature stability of the temperature monitoring point is qualified or not according to the fluctuation evaluation value, and if the temperature stability is qualified, analyzing the temperature fluctuation relevance of two adjacent points to obtain a comprehensive relevance evaluation value; and judging whether the axial temperature gradient needs to be subjected to temperature adjustment or not according to the comprehensive association evaluation value, and if yes, adjusting the axial temperature gradient.

The invention discloses a manufacturing process of a liquid hydrogen storage tank with a carbon-based anti-seepage coating on the inner wall. The manufacturing process comprises the following steps that a liquid hydrogen storage tank base body and the carbon-based anti-seepage coating are prepared; wherein the carbon-based anti-seepage coating comprises carbon nanotubes and polymer resin, and the mass fraction of the carbon nanotubes in the carbon-based anti-seepage coating is 30%-50%. And the surface of the inner wall of the liquid hydrogen storage tank base body is coated with the carbon-based anti-seepage coating, the carbon-based anti-seepage coating is cured, and the liquid hydrogen storage tank with the carbon-based anti-seepage coating on the inner wall is obtained. Wherein the thickness of the carbon-based anti-seepage coating is 30 + / -5 [mu] m. The liquid hydrogen storage tank carbon-based anti-seepage coating prepared through the method is high in adhesive force, excellent in anti-seepage performance and high in pressure resistance, and the carbon-based anti-seepage coating is uniform and free of bubbles, cracks and other defects in the preparation process.

This invention provides a metal electroplating composition comprising: a sulfur-containing compound, a tin salt, a silver salt, an acidic electrolyte, a surfactant, a brightener, an antioxidant, a pH adjuster, and water. The sulfur-containing compound is a compound of formula (I): wherein R1 is selected from primary, secondary, and tertiary amino groups; R2 is selected from straight-chain alkyl and branched-chain alkyl groups; R3 is selected from straight-chain alkyl and branched-chain alkyl groups; and R4 is selected from hydrogen and alkyl groups. Using the above technical solution, electroplating under high current density conditions can achieve the following technical effects: no pores or defects, low impurities in the plating layer, excellent plating uniformity, dense structure, and low surface roughness. The metal electroplating composition has good plating solution stability and plating uniformity, and can obtain consistently good appearance and film thickness uniformity of the plating film. It has good industrial application value.

The invention discloses a polyimide adhesive composition for semiconductor packaging as well as a preparation method and application thereof, and relates to the field of semiconductor packaging materials, and the polyimide adhesive composition for semiconductor packaging comprises the following components in parts by weight: 60-95 parts of alkyl silylated polyamide acid resin, 1-5 parts of an amino silane auxiliary agent, 5-40 parts of a diluent and 0.05-5 parts of an anti-foaming agent. Compared with the prior art, the high-performance adhesive successfully solves the long-standing core contradiction that'high adhesive force ', 'high insulation reliability' and'low-viscosity processability 'are difficult to consider in the field of high-performance adhesives mainly through an innovative molecular structure and formula design; powerful material support is provided for miniaturization, light weight and high-frequency and high-speed application of semiconductor devices, and the application prospect is wide.