Topology potential theory is a new community detection theory on complex network, which divides a network into communities by spreading outward from each local maximum potential node. At present, almost all topology-potential-based community detection methods ignore node difference and assume that all nodes have the same mass. This hypothesis leads to inaccuracy of topology potential calculation and then decreases the precision of community detection. Inspired by the idea of PageRank algorithm, this paper puts forward a novel mass calculation method for complex network nodes. A node’s mass obtained by our method can effectively reflect its importance and influence in complex network. The more important the node is, the bigger its mass is. Simulation experiment results showed that, after taking node mass into consideration, the topology potential of node is more accurate, the distribution of topology potential is more reasonable, and the results of community detection are more precise.

This study examines how political career incentives drive city leaders to strategically lease land to the service and industrial sectors within their terms of office and trigger political circles in land supply. Drawing on a comprehensive panel dataset covering 284 cities in China from 2006 to 2020, the results of panel regressions reveal a U-shaped correlation between mayors’ tenure in office and the quantity and proportion of land leased to the service sector for the 2006–2013 period, when economic growth was the overwhelming indicator of political performance. Newly appointed mayors are more motivated to stimulate long-term economic growth and supply more land to the industrial sector. As their tenure in office increases, mayors become less concerned with maximizing long-term economic growth and opt to lease more land to the service sector for immediate one-off proceeds. However, the U-shaped relationship has disappeared since 2013, when the cadre evaluation system was amended to prohibit using GDP growth as the primary criterion for evaluating local officials’ performance.