Manufacturing of railway rolling stock; manufacturing of special equipment; construction labor subcontracting; general items: manufacturing of railway rolling stock parts; manufacturing of urban rail transit equipment; manufacturing of high-speed rail equipment and parts; manufacturing of special machinery for tunnel construction; manufacturing of metallurgical special equipment; manufacturing of electrical signal equipment devices; manufacturing of electric motors; manufacturing of water turbines and auxiliary equipment; manufacturing of electric power dynamometers; sales of railway rolling stock parts; sales of railway transport equipment; manufacturing of electronic components and electromechanical component equipment; sales of electronic components and electromechanical component equipment; sales of power electronic components; sales of electronic products; operation of wires and cables; retail of hardware products; technical services, development, consulting, exchange, transfer and promotion; import and export of goods; import and export of technologies; import and export agency; installation services for general mechanical equipment; installation and maintenance of industrial robots; repair of computers and office equipment; repair and maintenance of motor vehicles; maintenance of transportation facilities; repair of electrical equipment; development of artificial intelligence application software; development of artificial intelligence basic software; software development; leasing of mechanical equipment; sales of mechanical equipment; system integration services; computer system services; manufacturing of computer software, hardware and peripheral equipment; wholesale of computer software, hardware and auxiliary equipment; labor services (excluding labor dispatch); manufacturing of special equipment (excluding licensed professional equipment manufacturing).