Abstract: A method of preparing PAN-based carbon fibers relates to the technical field of materials. The method includes: S1. acrylonitrile, a second monomer and an unsaturated UV-sensitive cross-linking agent are mixed, an initiator is then added and a reaction is performed to obtain a meltable PAN-based copolymer; S2. the meltable PAN-based copolymer and a flow modifier are mixed to obtain a mixture, the mixture is extruded and pelletized, and then melt spinning is performed to obtain nascent fibers, the nascent fibers are stretched and annealed to obtain a PAN-based carbon fiber precursor; S3. ultraviolet irradiation is performed on the PAN-based carbon fiber precursor; S4. the PAN-based carbon fiber precursor after ultraviolet irradiation is pre-oxidized and carbonized to obtain PAN-based carbon fibers.

Abstract: The present disclosure relates to a railway video resource interconnection and convergence system and a convergence method. The system includes: a security device and a railway video sharing cloud platform. The security device is configured to map, under the condition that a first resource network is physically isolated from other resource networks, an internet protocol address of the first resource network of video resources to an internet protocol address of a shared network; and the railway video sharing cloud platform is configured to acquire a stream of the video resources, and convert the stream of the video resources into a stream of a preset standard format. The present disclosure solves the problem of secure and effective integration of video resources of a professional video monitoring system in a railway and a comprehensive video monitoring system.