Acknowledgements
The research was partially supported by the School Foundation
of Changzhou University (Grant No. ZMF1102067), the Natural Science
Foundation of China (Grant No. 51308077) and the Natural
Science Foundation of the Jiangsu Higher Education Institutions of
China (Grant No. 13KJB560001). Mr. Ho Simon Wang at HUST Academic
Writing Center has provided tutorial assistance to improve
the manuscript.