Li Hang, Shen Yong-Jun, Yang Shao-Pu, Peng Meng-Fei, Han Yan-Jun. Simultaneous primary and super-harmonic resonance of Duffing oscillatorJ. Acta Physica Sinica, 2021, 70(4): 040502. DOI: 10.7498/aps.70.20201059