作者机构:[1]State Key Laboratory of Solidification Processing, Northwestern Polytechnical University,Xi'an 710072, China, [2]Department of Applied Physics, Northwestern Polytechnical University, Xi'an 710072,China
相关基金:This work was supported by the National Natural Science Foundation of China (No 50395103) and the Doctorate Foundation of Northwestern Polytechnical University. The authors would also like to thank Prof K. Jackson and L.Q. Xing for helpful discussion.