[Ning, Shangbo; Zhao, Yunjie; Li, Anbang] Cent China Normal Univ, Dept Phys, Wuhan 430079, Peoples R China.
[Ning, Shangbo; Zhao, Yunjie; Li, Anbang] Cent China Normal Univ, Inst Biophys, Wuhan 430079, Peoples R China.
[Liu, Maili; Gong, Zhou; Sun, Min; Dong, Xu] Chinese Acad Sci, Innovat Acad Precis Measurement Sci & Technol, State Key Lab Magnet Resonance & Atom Mol Phys, Wuhan 430071, Hubei, Peoples R China.
[Zeng, Chen] George Washington Univ, Dept Phys, Washington, DC 20052 USA.