1. School of Geosciences and Info-physics, Central South University , Changsha 410083 , China
2. Hunan Key Laboratory of Nonferrous Resources and Geological Hazard Exploration , Changsha 410083 , China
3. Key Laboratory of Metallogenic Prediction of Nonferrous Metals and Geological Environment Monitoring (Central South University), Ministry of Education , Changsha 410083 , China
4. Advanced Institute for Materials Research, Tohoku University , Sendai 980-8577 , Japan