Funding for this research was provided by:
National Natural Science Foundation of China (51402258)
Natural Science Foundation of Guangdong Province (2015A030313706)
Science and Technology Planning Project of Guangdong Province (2014A010105056)
Characteristic Creative Project in University of Guangdong Province (2014KTSCX189)
Science and Technology Planning Project of Zhaoqing City (2015B010402003)