Variational principles with mixed variables in elasticity and their applications 并列题名：Variational principles with mixed variables in elasticity and their applications Dimension reduction, variable selection and their applications Quasi-variational principles of non-conservative system and their applications 并列题名：Quasi-variational principles of non-conservative system and their applications Principles of nonlinear kalman filters and their applications 并列题名：Principles of nonlinear kalman filters and their applications