凯发电气：公司的主营业务为电气化铁路及城市轨道交通牵引供电系统的研发、生产和销售

Core Viewpoint - The company, Kaifa Electric (300407), focuses on the research, production, and sales of electrified railway and urban rail transit traction power supply systems, with no involvement in commercial aerospace business [1] Group 1: Business Focus - The company's main business is centered on the rail transit sector [1] - The company does not currently engage in commercial aerospace-related activities [1] Group 2: Operational Disclosure - The company's operational status and business scope should be verified through announcements published in legal information disclosure media [1]