Abstract: Disclosed is a preparation method for an SGLT2 inhibitor intermediate V, the method comprising: adding a compound IV to a solvent, and in the presence of a catalytic reagent, carrying out heat preservation reaction with a fluorination reagent. The preparation process for the intermediate V is simple in operations, mild in reaction conditions and high in safety, facilitates quality control and is suitable for industrial production. In addition, the intermediate V prepared by the method is high in purity, has few side reaction product monofluoro-impurity shown as structural Formula V?, is easy to purify, and is applicable to quality research on active pharmaceutical ingredients and preparations of the SGLT2 inhibitor.

Abstract: A multidentate phosphite ligand is used in the catalytic synthesis of adiponitrile. The ligand is represented by the following general formula (I). The method of catalytic synthesis of adiponitrile comprises primary hydrocyanation, isomerization, and secondary hydrocyanation reactions, wherein the catalyst adopted each comprises a phosphite ligand-nickel complex composed of a nickel precursor and a multidentate phosphite ligand. The ligand molecule has a higher electron cloud density, and the phosphorus content capable of participating in coordination in the ligand molecule per unit mass is higher, so that the catalytic activity of the catalyst is improved, and the amount of the catalyst is reduced.

Abstract: A photographing control method and apparatus, a computer device and a storage medium are provided. The method includes determining a first ratio, wherein the first ratio is a ratio of the current optical zoom ratio of a target photographic device to a maximum optical zoom ratio of the target photographic device; determining a second ratio, wherein the second ratio is a proportion of the area of a person face region currently captured by the target photographic device in a whole captured picture; determining whether the first ratio is less than or equal to a first ratio threshold and the second ratio is less than or equal to a second ratio threshold; and if yes, controlling the target photographic device to perform optical zoom, and if no, controlling the target photographic device to perform digital zoom.

Abstract: A method and apparatus for switching a main microphone of a plurality of microphones, a voice detection method and apparatus for a microphone, a microphone-loudspeaker integrated device, and a readable storage medium are provided. The method for switching the main microphone of the plurality of microphones includes: acquiring first audio data for playback by a loudspeaker, and acquiring second audio data acquired by each microphone and corresponding noise frequency domain energy; obtaining corresponding first frequency domain energy and second frequency domain energy according to the first audio data and the second audio data; when the first frequency domain energy is less than a first preset threshold, selecting a candidate main microphone according to the noise frequency domain energy and the second frequency domain energy corresponding to each microphone; and switching the candidate main microphone as a main microphone.