All kinds of engineering construction activities of the company; Import and export of goods; Import and export of technology (projects subject to approval according to law can only carry out business activities after approval by relevant departments. The specific business projects are subject to the approval documents or licenses of relevant departments) General projects: Technology Service, technology development, technology consultation, technology exchange, technology transfer, technology promotion; Sales of gas compression machinery; Sales of machinery and equipment; Sales of special instruments and meters for environmental monitoring; Sales of special equipment for environmental protection; Sales of gas and liquid separation and purification equipment; Sales of vacuum equipment; Sales of instruments and meters; Retail of hardware products; Sales of intelligent instruments and meters; Sales of power electronic components; Sales of mechanical parts and components; General machinery and equipment installation services; Machinery and equipment leasing; Office equipment leasing services; Contract energy management; Information Consulting services (excluding licensing information consulting services); Energy-saving management services; Machining of mechanical parts and components (limited to branch operations) (except for projects subject to approval according to law, business activities are carried out independently with business licenses).