Development, design, and manufacturing of power distribution and control equipment, automation control equipment, communication equipment, material handling equipment, environmental pollution prevention special equipment, explosion-proof electrical appliances, and industrial control systems; computer software development; sales of electronic computers and accessories, instruments and meters, hardware, electrical appliances, and office supplies; equipment leasing; self-owned property leasing; self-operated and agent import and export of various commodities and technologies, except for commodities and technologies restricted or prohibited by the state; research and development, sales, manufacturing, and maintenance services of underground mining vehicles; coal sales; equipment leasing; self-owned property leasing.