55results about How to "Little change in content" patented technology

The invention relates to a smelting method of bearing steel, in particular to a preparation method of the bearing steel with the low titanium content. The bearing steel comprises, by mass, no more than 0.0018% of Ti, more than 0.4% of Si (preferably, 0.4-0.6%), and more than 0.9% of C (preferably, 0.90-1.00%). The preparation method comprises the steps of primary smelting, fine smelting, vacuum degassing, pouring and rolling. According to the preparation method, the problem that the titanium content of a bearing steel product is too high is solved under the condition that the smelting cost isnot increased.

The invention relates to a preparation method of a high-storage-stability polyester-type polyurethane prepolymer, which comprises the following steps: adding a nitrogen-containing metallic ion complexing agent into a hydroxyl-terminated low-polymer polyester polyol; dewatering at 95-130 DEG C under the vacuum degree of 0.08-0.09 MPa for 2 hours; cooling to 30-55 DEG C, mixing with 2,4-toluene diisocyanate, and reacting at controlled temperature of 30-65 DEG C for 0.5 hour; heating to 70-95 DEG C, and keeping the reaction for 2 hours; adding a polymerization inhibitor, and deaerating at controlled temperature of 70-95 DEG C under the pressure of 0.08-0.09 MPa for 0.5 hour to obtain the high-storage-stability polyester-type polyurethane prepolymer; and after measuring that the percentage of NCO (isocyanate-group) in the prepolymer is equivalent to a set value, cooling, charging nitrogen, and storing in a closed environment. The change rate of the percentage of NCO in the obtained polyester-type polyurethane prepolymer is less than 0.2%, and thus, the polyester-type polyurethane prepolymer can be stored stably.

The invention provides a carbohydrate and electrolyte injection which comprises the following components by weight part: 30 parts of glucose, 15 parts of fructose, 7.5 parts of xylitol, 0.73 part of sodium chloride, 0.41 part of sodium acetate, 0.185 part of calcium chloride, 0.255 part of magnesium chloride, 0.87 part of dipotassium phosphate, 0.0007 part of zinc sulfate, 0.21 part of sodium bisulfite and 250 parts of water for injection; and the PH value is 5.1-5.5. The injection is low in cost and wide in applicable range. The invention also provides a preparation method of the carbohydrate and electrolyte injection. The preparation method comprises the steps of dissolving carbohydrate and electrolyte (as raw and auxiliary materials), absorbing, decarbonizing, adjusting the pH, and sterilizing to obtain the carbohydrate and electrolyte injection. According to the preparation method, the process is simple, the method is suitable for industrial production, the problems that samples turn yellow after the sterilization, and white substances are separated out can be avoided by increasing the dissolving temperature to be 75 DEG C-85 DEG C and adjusting the pH of the solution, so that the carbohydrate and electrolyte injection is stable.

The invention provides a molecularly imprinted monodisperse microsphere with a specific adsorption function for tobacco-specific nitrosamines, characterized in that the molecularly imprinted monodisperse microsphere uses nicotinamide as a template molecule and methacrylic acid As a functional monomer, trimethylolpropane trimethacrylate is used as a cross-linking agent, polystyrene emulsion is used as a seed ball, and phthalic acid is used as a swelling agent. It is synthesized by swelling polymerization and provides this molecule Preparation and application of imprinted monodisperse microspheres. In the molecularly imprinted monodisperse microspheres provided by the invention, the particles are uniform, the dispersibility is good, and it has a specific adsorption effect on tobacco-specific nitrosamines, which can effectively reduce the toxic components in cigarettes without significantly affecting their original quality. .

The invention relates to the technical field of welding, in particular to a fluorine-free melting flux and a preparation method and application thereof. The fluorine-free smelting flux is made of the following components by mass percentage: SiO 2 20%~41%, MnO 30%~61% and TiO 2 15%~50%. The preparation method of the fluorine-free smelting flux includes: mixing the raw materials uniformly and then sequentially smelting and water quenching to obtain an intermediate material; and roasting the intermediate material to obtain the fluorine-free smelting flux. In the application of the fluorine-free smelting flux in the field of welding, the fluorine-free smelting flux is used in combination with a welding wire to weld structural steel for ships and marine engineering. The flux not only does not contain fluorine, but also avoids the addition of CaF in the prior art. 2 In addition, the flux can ensure that the welded joint obtained after welding has high mechanical properties.