title: Photoswitchable upconversion luminescence of rare-earth nanophosphors with covalently grafted spiropyran.
authors.affiliation: Beijing National Laboratory for Molecular Sciences, State Key Laboratory of Rare Earth Materials Chemistry and Applications, PKU-HKU Joint Laboratory in Rare Earth Materials and Bioinorganic Chemistry, Peking University, Beijing 100871, P. R. China.
authors.forename: Chao
authors.initials: C
authors.lastname: Zhang
authors.forename: Chun-Hu
authors.initials: CH
authors.lastname: Xu
authors.forename: Ling-Dong
authors.initials: LD
authors.lastname: Sun
authors.forename: Chun-Hua
authors.initials: CH
authors.lastname: Yan