Technical consultation, technology development, technology transfer and service in the field of automation equipment science and technology; Vacuum equipment repair and maintenance; Solar photovoltaic system engineering; Sales of electronic products, photovoltaic products and accessories, vacuum equipment and spare parts, engaged in the import and export of goods and technology business. [For projects subject to approval according to law, business activities can only be carried out after approval by relevant departments]; Building materials sales; Metal material sales; Building decoration materials sales; Sales of metal products; Metal structure sales; Sales of doors and Windows; Electric wire and cable operation; Sales of chemical products (excluding licensed chemical products); Sales of electronic products; Commodity sales; Sales of arts and crafts and ceremonial articles (except ivory and its products); Technical glass products sales; Sales of graphite and carbon products; Domestic trade agent. (Except for the items subject to approval according to law, the company shall independently carry out business activities according to law with the business license). The permitted business items are: Production, maintenance and transformation of mechanical equipment, electronic products, photovoltaic products and automation equipmen