Alibaba Group Holding Limited

Hangzhou Normal University

Hangzhou Transfar Fine Chemical Co., Ltd.

Zhejiang Transfar Functional New Material Co., Ltd.

Xiaojun Wang

Pengfei Zhang

Weiming Xu

Bajin Chen

Shengpeng Wang

Qiang Zhang

Wanmei Li

Chuan Qin

Xiaobo Yang

Hanyang Zeng

Bencheng Yu

Changdong Han

Youju Huang

Jinxing Song

Disclosed are (2,2-dimethyl-1,3-dioxolan-4-yl)methyl 2-bromo-2,2-difluoroacetate, a waterborne polyurethane, and preparation methods thereof. The (2,2-dimethyl-1,3-dioxolan-4-yl)methyl 2-bromo-2,2-difluoroacetate could be used as a modified monomer for preparing a waterborne polyurethane, and substituents at a C2 position of the (2,2-dimethyl-1,3-dioxolan-4-yl)methyl 2-bromo-2,2-difluoroacetate are two fluorine atoms and one bromine atom. When it is used for preparing the waterborne polyurethane, fluorine and bromine groups are introduced into the structure of the waterborne polyurethane, and the resultant waterborne polyurethane exhibits good moisture resistance and flame retardance.

2,2-dimethyl-1,3-dioxolan-4-yl-methyl 2-bromo-2,2-difluoroacetate, waterborne polyurethane, and preparation methods thereof

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Methods, systems, and devices, including computer programs encoded on computer storage media, for establishing a question and answer (QA) system are provided. One of the methods includes: determining QA pair data according to an extraction template and a target data source; adjusting the extraction template according to anomaly information corresponding to the QA pair data; updating the QA pair data according to the target data source and the adjusted extraction template; and determining a QA index according to the updated QA pair data to establish a QA system.

Method, apparatus, storage medium and electronic device for establishing question and answer system

A method for preparing alkynyl 2-halo-2,2-difluoroacetate is disclosed. The method comprises: subjecting a 2-halo-2,2-difluoro acetic acid, an alkynol, and a catalyst to an esterification reaction in a solvent, to obtain alkynyl 2-halo-2,2-difluoroacetate, wherein the catalyst includes one or more of sulfuric acid, phosphoric acid and p-toluenesulfonic acid.

Method for preparing alkynyl 2-halo-2,2-difluoroacetate

Embodiments of the present specification provide a corpus generating method and apparatus, and a human-machine interaction processing method and apparatus, wherein the corpus generating method comprises: generating a corpus vector according to corpus content; determining a vector type of the corpus vector; and generating, according to the vector type and the corpus vector, a corpus having an inverted chain index.

Corpus generating method and apparatus, and human-machine interaction processing method and apparatus

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Hangzhou, China

Xiaojun Wang