1. Institute of special materials and technologyFudan University Shanghai P. R. China
2. Department of Chemistry and Shanghai Key Laboratory of Molecular Catalysis and Innovative MaterialsFudan University Shanghai P. R. China
3. State Key Laboratory for Mechanical Behavior of MaterialsXi'an Jiaotong University Xi'an P. R. China
4. Department of Mechanical EngineeringGeorge Mason University Fairfax VA 22030 USA
5. Department of Materials Science and NanoEngineeringRice University Houston TX 77251‐1892 USA