[1
]School of Economics and Management, Shaanxi University of Science & Technology, Xi’an,
Shaanxi, China
[2
]School of Economics and Management, Ankang University, AnKang, Shaanxi, China
[3
]Northwest Institute of Historical Environment and Socio-Economic Development, Shaanxi
Normal University, Xi'an, Shaanxi, China
[4
]School of Economics and Management, Leshan Normal University, Leshan, Sichuan, China