TY - Journal of Geo-information Science A1 - LIU Tianyu, CHEN Xiaolin, LI Qiang, CHEN Jin T1 - The Centripetal Expansion Index and Its Application in Urban Spatial Expansion in Zhengzhou Metropolitan Area Y1 - 2022-11-25 00:00:00.0 JF - Journal of Geo-information Science JO - Journal of Geo-information Science SP - 1771 EP - 1784 VL - 24 IS - 9 UR - {https://www.dqxxkx.cn/EN/10.12082/dqxxkx.2022.220039} N1 - 10.12082/dqxxkx.2022.220039 ER -