This work was partially supported by the National Natural Science Foundation of China (51472174, 61604086, and 21776147), the International Science & Technology Cooperation Program of China (2014DFA60150), the Department of Science and Technology of Shandong Province (ZR2018BB066 and 2016GGX104010), and the Department of Education of Shandong Province (J16LA14). L. F. Dong also thanks financial support from the Malmstrom Endowment Fund at Hamline University.
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