Abstract: The present invention provides a method for manufacturing a hot-dip galvanized steel sheet, comprising performing a heat treatment step, a hot dip plating step, and an alloying treatment step on a steel sheet having high Si and Mn content. The heat treatment step comprises a first heating phase and a soaking phase; a first heating atmosphere of the first heating stage contains 0.01-0.5% of O2 by volume, and the balance is N2 and inevitable impurities; a soaking atmosphere of the soaking stage contains 0.5% or more of H2 by volume, and the balance is N2 and inevitable impurities; dew points of the first heating atmosphere and the soaking atmosphere are controlled to be greater than or equal to ?20° C. The present invention further provides a hot-dip galvanized steel sheet and a vehicle component.

Abstract: Crystal forms A, B, C, D, E, F, G and H of a compound represented by formula I and a preparation method therefor, as well as medical uses for the various crystal forms and advantages thereof in various aspects.

Abstract: The invention discloses a 780 MPa cold-rolled dual-phase strip steel having a microstructure of fine equiaxed ferrite matrix and martensite islands distributed homogeneously on the ferrite matrix, and comprising the following chemical elements in mass percentage: C: 0.06-0.1%; Si?0.28%; Mn: 1.8-2.3%; Cr: 0.1-0.4%; Mo: not added when Cr?0.3%; Mo=0.3—Cr when Cr<0.3%; Al: 0.015-0.05%; at least one of Nb and Ti elements, wherein Nb+Ti is in the range of 0.02-0.05%; and the balance amounts of Fe and other unavoidable impurities. Correspondingly, the invention also discloses a method for manufacturing the 780 MPa cold-rolled dual-phase strip steel. The 780 MPa cold-rolled dual-phase strip steel has high strength, superior elongation, good phosphating property and small anisotropy in mechanical properties.

Abstract: Disclosed is a new method for preparing an azetidinone compound represented by formula (I). The carboxylic ketoester represented by formula (II) serves as the raw material and is subjected to Grignard addition, stereoselective dehydration, ester group reduction, hydroxyl group protection, addition with imine after condensation with a chiral auxiliary, cyclization and deprotection to obtain the compound represented by formula (I). The present invention has advantages of easily available raw material, a few synthetic steps, simple operation, high yield, good stereoselectivity and low cost, and can be used for industrial production.

Abstract: Disclosed is a new method for preparing an azetidinone compound represented by formula (I). The carboxylic ketoester represented by formula (II) serves as the raw material and is subjected to Grignard addition, stereoselective dehydration, ester group reduction, hydroxyl group protection, addition with imine after condensation with a chiral auxiliary, cyclization and deprotection to obtain the compound represented by formula (I). The present invention has advantages of easily available raw material, a few synthetic steps, simple operation, high yield, good stereoselectivity and low cost, and can be used for industrial production.

Abstract: Disclosed is a new method for preparing an azetidinone compound represented by formula (I). The carboxylic ketoester represented by formula (II) serves as the raw material and is subjected to Grignard addition, stereoselective dehydration, ester group reduction, hydroxyl group protection, addition with imine after condensation with a chiral auxiliary, cyclization and deprotection to obtain the compound represented by formula (I). The present invention has advantages of easily available raw material, a few synthetic steps, simple operation, high yield, good stereoselectivity and low cost, and can be used for industrial production.

Abstract: Disclosed is a new method for preparing an azetidinone compound represented by formula (I). The carboxylic ketoester represented by formula (II) serves as the raw material and is subjected to Grignard addition, stereoselective dehydration, ester group reduction, hydroxyl group protection, addition with imine after condensation with a chiral auxiliary, cyclization and deprotection to obtain the compound represented by formula (I). The present invention has advantages of easily available raw material, a few synthetic steps, simple operation, high yield, good stereoselectivity and low cost, and can be used for industrial production.

Abstract: The invention discloses a 780 MPa cold-rolled duel-phase strip steel having a microstructure of fine equiaxed ferrite matrix and martensite islands distributed homogeneously on the ferrite matrix, and comprising the following chemical elements in mass percentage: C:0.06-0.1%; Si?0.28%; Mn:1.8-2.3%; Cr:0.1-0.4%; Mo: not added when Cr?0.3%; Mo=0.3-Cr when Cr<0.3%; Al: 0.015-0.05%; at least one of Nb and Ti elements, wherein Nb+Ti is in the range of 0.02-0.05%; and the balance amounts of Fe and other unavoidable impurities. Correspondingly, the invention also discloses a method for manufacturing the 780 MPa cold-rolled duel-phase strip steel. The 780 MPa cold-rolled duel-phase strip steel has high strength, superior elongation, good phosphating property and small anisotropy in mechanical properties.