Information systems department. The main business departments of university libraries are acquisition department, cataloging department, circulation department and information system department. Document retrieval and document delivery belong to the department of library information system. The Information System Department is the comprehensive information technology service department of the library, which provides reference service, literature retrieval course teaching, reader training, sci-tech novelty retrieval, retrieval and citation retrieval, document delivery, software and hardware equipment maintenance, management and update, and is responsible for the construction and management of electronic literature resources and digital resources reading room.