Abstract: A polynucleotide having promoter activity of a malate dehydrogenase gene (mdh gene), a transcription expression cassette, recombinant expression vector and recombinant host cell containing the polynucleotide having the promoter activity, a method for constructing a promoter mutant, a method for regulating the transcription of a target gene, a method for preparing a protein, and method for producing a target compound. The polynucleotide having the promoter activity is a mutant of an mdh gene promoter, and compared with a promoter of a wild-type mdh gene, the promoter activity of the mutant is significantly improved. After operably linking the mutant to a target gene, the expression efficiency of the target gene can be significantly improved, thereby effectively improving the yield and transformation rate of a target compound.

Abstract: Disclosed are a slow-release inhibitor for high-magnesium sulfide mineral flotation and an application thereof, where the inhibitor is a nano colloidal particle of an alkaline earth fluoride such as CaF2 and BaF2 or a highly-reactive natural alkaline earth metal mineral powder. When applied to the flotation separation of a high-magnesium sulfide ore, the inhibitor can slowly release F ions to preferentially form a MgF2 layer on the magnesium-containing mineral surface, which provides a structure similar to MgF2 on a surface of oxidized gangue minerals such as magnesium oxide, changing surface electrical property of the magnesium-containing mineral, inhibiting heterogeneous coagulation of magnesium-containing minerals and sulfide ores due to electrostatic attraction and reducing entrainment, enveloping and agglomeration of gangue minerals to efficiently inhibit the flotation of oxidized gangue minerals such as magnesium oxide.

Abstract: Disclosed are a slow-release inhibitor for high-magnesium sulfide mineral flotation and an application thereof, where the inhibitor is a nano colloidal particle of an alkaline earth fluoride such as CaF2 and BaF2 or a highly-reactive natural alkaline earth metal mineral powder. When applied to the flotation separation of a high-magnesium sulfide ore, the inhibitor can slowly release F ions to preferentially form a MgF2 layer on the magnesium-containing mineral surface, which provides a structure similar to MgF2 on a surface of oxidized gangue minerals such as magnesium oxide, changing surface electrical property of the magnesium-containing mineral, inhibiting heterogeneous coagulation of magnesium-containing minerals and sulfide ores due to electrostatic attraction and reducing entrainment, enveloping and agglomeration of gangue minerals to efficiently inhibit the flotation of oxidized gangue minerals such as magnesium oxide.

Abstract: The present invention provides a functional diene polymer, a preparation method thereof and a rubber composition comprising the functional diene polymer. The functional diene polymer comprises at least one type of conjugated diene structural units and silane coupler functional units represented by formula (I) in its molecular chain, and the number-average molecular weight of the functional diene polymer is 50,000˜1,000,000; R1-R4 are C1-C20 linear or branched alkyl or heteroatom-containing C1-C20 linear or branched alkyl, and the heteroatom is selected from one or more of halogen, oxygen, sulfur, silicon, and phosphorus. Not only the relationship between the wet slip resistance and the rolling resistance of the functional diene polymer is effectively improved, but also the offensive odor produced in the rubber mixing process owing to the addition of the silane coupler is reduced.

Abstract: The present invention provides a functional diene polymer, a preparation method thereof and a rubber composition comprising the functional diene polymer. The functional diene polymer comprises at least one type of conjugated diene structural units and silane coupler functional units represented by formula (I) in its molecular chain, and the number-average molecular weight of the functional diene polymer is 50,000˜1,000,000; R1-R4 are C1-C20 linear or branched alkyl or heteroatom-containing C1-C20 linear or branched alkyl, and the heteroatom is selected from one or more of halogen, oxygen, sulfur, silicon, and phosphorus. Not only the relationship between the wet slip resistance and the rolling resistance of the functional diene polymer is effectively improved, but also the offensive odor produced in the rubber mixing process owing to the addition of the silane coupler is reduced.

Abstract: This invention relates to a thermoplastic elastomeric block copolymer and process for the preparation thereof. According to this invention, the block copolymer obtained through block copolymerization process at higher temperature and adding butyllithium in twice during copolymerization are mixed block copolymer of A.sub.1 -B-A.sub.2 /B-A.sub.2 and B-A.sub.2 /B-A.sub.2 (where A represents monovinyl aromatic monomer; B represents conjugated diene monomer) having different blocks, higher elongation and appropriate melt index. The process of this invention is simple and efficient. The thermoplastic elastomeric block copolymer of this invention are particularly useful for various applications of typical styrene butadiene block copolymer, especially plastic modifier.