Technology promotion and application services; Electronic product sales; Wholesale of electronic components: Retail of electronic components; Sales of electronic specialized materials: Sales of mechanical parts and components; Sales of power electronic components; Sales of mechanical and electrical equipment; Sales of electrical equipment; Sales of electrical signal equipment devices; Sales of valves and plugs; Sales of pumps and vacuum equipment; Sales of gas compression machinery; Sales of electric accessories for new energy vehicles; Sales of high-performance sealing materials; Sales of mechanical equipment; Sales of refrigeration and air conditioning equipment; Sales of solar thermal utilization equipment; Sales of household appliance spare parts; General equipment repair; Bearing sales; Sales of high-speed precision heavy-duty bearings; Computer and office equipment maintenance; Home goods sales: Retail of computer software, hardware, and auxiliary equipment; Sales of industrial control computers and systems; Computer system services: Sales of information security equipment; Sales of calculator equipment; Information system integration services; Information technology consulting services; Retail of hardware products; Internet sales (except for the sale of goods that need to be licensed); Technology intermediary services; Software development; Development of artificial intelligence application software; Digital technology services; Software sales; Technical services, technology development, technology consulting, technology exchange, technology transfer, and technology promotion; Technology promotion services; Research and development of Internet of Things technology