1. Department of Mechanical EngineeringUniversity of Delaware Newark DE19716 USA
2. Department of Engineering MechanicsDalian University of Technology Dalian 116024 China
3. State Key Laboratory of Solidification ProcessingCenter for Nano Energy MaterialsSchool of Materials Science and EngineeringNorthwestern Polytechnical University and Shaanxi Joint Laboratory of Graphene (NPU) Xi'an 710072 China