Research on key issues of free piston engine generator system 并列题名:Research on key issues of free piston engine generator system Design theory and method of free piston engine generator system 并列题名:Design theory and method of free piston engine generator system Simulation and experimental techniques of free piston engine generator system 并列题名:Simulation and experimental techniques of free piston engine generator system Research on the design of Chinese insolvency administrator system Research on related issues of the construction of China's energy market system 并列题名:Research on related issues of the construction of China's energy market system Research on key issues of civil affairs