[Liu, Chao] Shandong Univ, Qingdao Inst Humanities & Social Sci, Ctr Yellow River Ecosyst Prod, Qingdao 266237, Peoples R China.
[Liu, Chao; Li, Jia; Lu, Xinhai] Cent China Normal Univ, Coll Publ Adm, Fac Polit Sci, Wuhan 430079, Peoples R China.
[Cheng, Long] Shandong Univ, Sch Polit Sci & Publ Adm, Qingdao 266237, Peoples R China.
[Xu, Yueqing] China Agr Univ, Coll Land Sci & Technol, Beijing 100193, Peoples R China.
[Yang, Qingke] Nanjing Univ Finance & Econ, Sch Publ Adm, Nanjing 210023, Peoples R China.