China Petroleum Chemical Corporation

Research Institute of Petroleum Processing, Sinopec

Sursen Corporation

Beijing Sursen International Information Tech Co.

Yunming Zhang

Peng Gao

Donglin Wang

Changwei Liu

Ningsheng Liu

Shutian Yin

Yuansong Liang

Yongzhi Lou

De Ouyang

Ming Zhao

Longsheng Tian

Wencheng Tang

Zhifeng Bian

Huixia Sun

Shijin Wu

A novel method is disclosed for detecting hidden information in a document comprising characters, including: determining layout transformation for each character in the document for detection compared with the original document; obtaining a code sequence embedded in the document for detection based on the layout transformation of each character in the document for detection and the predetermined embedding rule; decoding the code sequence to get the hidden information embedded in the document for detection.

Embedding and detecting hidden information

A novel method is disclosed for embedding hidden information in a document comprising characters, including: determining hidden information to be embedded in each class of layout transformation respectively; acquiring a code sequence for each class of layout transformation by coding the hidden information to be embedded in the class of layout transformation; performing layout transformation on characters from the document according to the acquired code sequence for each class of layout transformation respectively.

This application relates to a composite solvent for separating aromatics by extractive distillation, comprising a main solvent, a solutizer and a modifier. Said solutizer is selected from any one or mixtures of any two of C&#x2013;Caromatics having different number of carbon atoms, the content of which is 3&#x2013;39 wt %, and the number of carbon atoms of the lowest aromatic in the solutizer should be greater than that of the highest aromatic in the aromatics to be separated. When the solutizer is selected from any one of C&#x2013;Caromatics, the composite solvent contains 0.01&#x2013;10.0 wt % of the modifier; when the solutizer is selected from mixtures of any two of C&#x2013;Caromatics having different number of carbon atoms, the composite solvent contains 0&#x2013;10.0 wt % of the modifier. Said main solvent and modifier are independently selected from sulfolane derivatives, N-formyl morpholine, and N-methyl pyrrolidone, provided that the acidity and basicity of the modifier are opposite to those of the main solvent. When the composite solvent is used to recover aromatics by extractive distillation, it is possible to moderate the operation conditions of solvent recovery, increase the yield of aromatics, and make the separated aromatics to be neutral.

Process for separating aromatics by extractive distillation and a composite solvent used therein

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Beijing, China

Yunming Zhang