Abstract: A liquid crystal display panel includes a first base, a second base disposed opposite to the first base, a liquid crystal layer and a first optical compensation layer that are disposed between the first base and the second base, and a second optical compensation layer disposed on a side of the first base away from the liquid crystal layer or on a side of the second base away from the liquid crystal layer. An orthogonal projection of an optic axis of the first optical compensation layer on the first base is parallel to orthogonal projections of optic axes of liquid crystal molecules in the liquid crystal layer on the first base. An orthogonal projection of an optic axis of the second optical compensation layer on the first base is perpendicular to the orthogonal projection of the optic axis of the first optical compensation layer on the first base.

Abstract: Provided are a display panel and a method for preparing same, and a display apparatus. The display panel includes an array substrate and an opposite substrate, which are oppositely arranged, and a liquid crystal layer, which is arranged between the array substrate and the opposite substrate, wherein a compensation layer is arranged on the array substrate or the opposite substrate, and an included angle between an optical axis direction of the compensation layer and an initial optical axis direction of liquid crystal molecules in the liquid crystal layer is less than or equal to 10 degrees; dispersion characteristics of the liquid crystal layer and the compensation layer are the opposite of each other.

Abstract: A liquid crystal display panel includes: a first base, a second base disposed opposite to the first base, a liquid crystal layer and a first optical compensation layer that are disposed between the first base and the second base, and a second optical compensation layer disposed on a side of the first base away from the liquid crystal layer or on a side of the second base away from the liquid crystal layer. An orthogonal projection of an optic axis of the first optical compensation layer on the first base is parallel to orthogonal projections of optic axes of liquid crystal molecules in the liquid crystal layer on the first base. An orthogonal projection of an optic axis of the second optical compensation layer on the first base is perpendicular to the orthogonal projection of the optic axis of the first optical compensation layer on the first base.

Abstract: The present invention discloses a transaminase mutant and application thereof in preparation of sitagliptin intermediates, the transaminase mutant is obtained by substitution of tyrosine with proline at position 74, substitution of glutamic acid with aspartic acid at position 228, substitution of leucine with alanine at position 254 and substitution of methionine with threonine at position 290 of the amino acid sequence shown in SEQ ID NO: 2. The present invention uses wet cells or a purified transaminase as a biocatalyst and a sitagliptin precursor ketone or a prochiral carbonyl compound as a substrate to prepare a sitagliptin intermediate or a sitagliptin ester intermediate; the total yield of the method reaches about 82%, and e.e. value of the product reaches 99%.

Abstract: The present invention relates to a method for synthesizing a compound of 3-(difluoromethyl)-1-methyl-1h-pyrazole-4-carboxylic acid, wherein including the steps of: (A) the diethyl ester compounds represented by the following Formula IV are reacted under the action of amine, alkali and carbonyl reagents to produce the acrylic diester compound represented by the following Formula I, wherein: (B) the above compound represented by the Formula I is reacted with a fluoride reagent, a Lewis acid and a methyl hydrazine to form a pyrazole ring-containing diester compound represented by the Formula II, (C) the heterocyclic-containing diester compound represented by the Formula II is reacted with a base to give 3-(difluoromethyl)-1-methyl-1h-pyrazole-4-carboxylic acid represented by the Formula III.

Abstract: Provided are a preparation method for synthesizing a pyrazolecarboxylic acid derivative of the following formula (I), which is suitable for industrial production, and an intermediate as shown by the following formula (II). The method is high in reaction yield in each step, low in waste gas and waste water and low in cost, and requires no special reaction equipment.

Abstract: The present invention relates to a method for synthesizing a compound of 3-(difluoromethyl)-1-methyl-1h-pyrazole-4-carboxylic acid, wherein including the steps of: (A) the diethyl ester compounds represented by the following Formula IV are reacted under the action of amine, alkali and carbonyl reagents to produce the acrylic diester compound represented by the following Formula I, wherein (B) the above compound represented by the Formula I is reacted with a fluoride reagent, a Lewis acid and a methyl hydrazine to form a pyrazole ring-containing diester compound represented by the Formula II, (C) the heterocyclic-containing diester compound represented by the Formula II is reacted with a base to give 3-(difluoromethyl)-1-methyl-1h-pyrazole-4-carboxylic acid represented by the Formula III.

Abstract: Provided are a preparation method for synthesizing a pyrazolecarboxylic acid derivative of the following formula (I), which is suitable for industrial production, and an intermediate as shown by the following formula (II). The method is high in reaction yield in each step, low in waste gas and waste water and low in cost, and requires no special reaction equipment.