School of Science, Xi’an Polytechnic University, Xi’an, China; School of Mathematics and Statistics, Xidian University, Xi’an, China; School of Science, Chang’an University, Xi’an, China
LiuEtAl2017 funding source(s)
Supported by the National Natural Science Foundation of China (No. 11401453), the Education Teaching Funds for the Central Universities (No. 310612176301), and Scientific Research Program Funded by Shaanxi Provincial Education Department (No. 16JK1331).