Van der Pol-Duffing单边约束系统
Van der Pol-Duffing one-sided constraint system
板材四面折边单元
sheet metal four edge folding cell
半单边带传输系统
quasi-single sideband transmission system
边远地区分级标准
Australian standard geographic classification-rural areas system
边远地区高职院校
vocational colleges in remote areas