作者机构:[1]College of Materials Science and Engineering, Henan University of Science and Technology, Luoyang 471003, China
相关基金:Acknowledgements This work was supported by the Startup Foundation for Doctor Scientific Research in Henan University of Science and Technology (No. 20061009) and the Special Fund for Important Forepart Research in Henan University of Science and Technology (No. 2008ZD003), and the National Natural Science Foundation of China under grant No. 50771042.