Study on the duality of fear in school and its alleviating mechanism 并列题名：Study on the duality of fear in school and its alleviating mechanism Study on the government debt management and risk early warning mechanism Study on the risk management of urban public emergency and its realization mechanism Research on the philosophy of electric power law and its governance mechanism Study of urban affordable housing system in China and its operating mechanism Study on the theory of well-cycling and it's regulation and control mechanism 并列题名：Study on the government debt management and risk early warning mechanism