1. School of Chemical and Material Science, Key Laboratory of Magnetic Molecules & Magnetic Information Materials, the Ministry of Education, Shanxi Normal University. No. 339, Taiyu Road, Taiyuan, Shanxi 030031, People’s Republic of China
2. School of Geographical Sciences, Shanxi Normal University. No. 339, Taiyu Road, Taiyuan, Shanxi 030031, People’s Republic of China