1. Beijing Key Laboratory of Construction Tailorable Advanced Functional Materials and Green Applications School of Materials Science & Engineering Beijing Institute of Technology Beijing 100081 P. R. China
2. Materials Science and Engineering Program and Texas Materials Institute The University of Texas at Austin Austin TX 78712 USA
3. Center of Interdisciplinary Magnetic Resonance National High Magnetic Field Laboratory 1800 East Paul Dirac Drive Tallahassee FL 32310 USA
4. Department of Chemistry and Biochemistry Florida State University Tallahassee FL 32306 USA