Abstract: Disclosed is a method for preparing a heteropolyacid salt catalyst, comprising dissolving the lead compounds for each element to prepare a suspension and dispersion slurry of catalyst precursor, which comprises all of the catalyst components; drying the catalyst precursor, mixing them with an organic compound, molding, and calcining to produce the catalyst.

Abstract: Provided is a voiceprint-recognition-based security protection method. The method includes: acquiring voice data of a current user of a terminal and extracting voiceprint characteristic information from the voice data; matching the extracted voiceprint characteristic information of the current user of the terminal with a pre-saved voiceprint model of an owner of the terminal, and judging whether the current user of the terminal is the owner of the terminal; and when judging that the current user of the terminal is not the owner of the terminal, performing security protection processing on the terminal.

Abstract: A method for preparing methacrolein from t-butanol, specifically a method for preparing methacrolein by using t-butanol as a starting material, is disclosed, comprising passing the starting material through a fixed bed reactor filled with catalyst, wherein the fixed bed reactor is divided to n reaction zones from the inlet of the starting material to the outlet of the starting material and each zone is filled with catalysts of different catalytic activities; wherein the catalytic activity of the catalyst in the first reaction zone is higher than the catalytic activity of the catalyst in the second reaction zone, and the catalytic activity of the catalyst is gradually increased from the second reaction zone to the last reaction zone; and n is an integer between 3 to 10.

Abstract: Disclosed is a method for preparing a heteropolyacid salt catalyst, comprising dissolving the lead compounds for each element to prepare a suspension and dispersion slurry of catalyst precursor, which comprises all of the catalyst components; drying the catalyst precursor, mixing them with an organic compound, molding, and calcining to produce the catalyst.

Abstract: A method for preparing methacrolein from t-butanol, specifically a method for preparing methacrolein by using t-butanol as a starting material, is disclosed, comprising passing the starting material through a fixed bed reactor filled with catalyst, wherein the fixed bed reactor is divided to n reaction zones from the inlet of the starting material to the outlet of the starting material and each zone is filled with catalysts of different catalytic activities; wherein the catalytic activity of the catalyst in the first reaction zone is higher than the catalytic activity of the catalyst in the second reaction zone, and the catalytic activity of the catalyst is gradually increased from the second reaction zone to the last reaction zone; and n is an integer between 3 to 10.

Abstract: The present invention provides a complex oxide catalyst whose general formula is Mo12VaCubWcXdYeOf/Z. reducing agent needs to be added into the catalyst during the preparation process of the active component of the catalyst and (or) molding process of the catalyst. Specifically, X is at least one selected from a group consisting of Nb, Sb, Sr, Ba and Te; Y is at least one selected from a group consisting of La, Ce, Nd, Sm and Cs; “a” is ranging from 2 to 8; “b” is ranging from 1 to 6; “c” is ranging from 0.5 to 5; “d” is ranging from 0.01 to 4; “e” is ranging from 0.01 to 4; f is determined by the oxidation state of the component element; Z is silicon powder; the reducing agent is C2˜C6 diol or polyol.

Abstract: The present invention provides a complex oxide catalyst whose general formula is Mo12VaCubWcXdYeOf/Z. reducing agent needs to be added into the catalyst during the preparation process of the active component of the catalyst and (or) molding process of the catalyst. Specifically, X is at least one selected from a group consisting of Nb, Sb, Sr, Ba and Te; Y is at least one selected from a group consisting of La, Ce, Nd, Sm and Cs; “a” is ranging from 2 to 8; “b” is ranging from 1 to 6; “c” is ranging from 0.5 to 5; “d” is ranging from 0.01 to 4; “e” is ranging from 0.01 to 4; f is determined by the oxidation state of the component element; Z is silicon powder; the reducing agent is C2˜C6 diol or polyol.