The development of traditional resource-based cities requires drastic changes owing to the exhaustion of resources. During this transformation, the ecological environment of resource-based cities is threatened because of resource exploitation, in addition to the ecological risks caused by urban expansion. However, there is currently a lack of research on the evolution of ecological dangers in cities during this transformational period. Therefore, conducting relevant studies is essential to establishing a mechanism to mitigate these dangers. The present study analyzed Xuzhou, a typical resource-based city in China, as a case study. The main objective was to consider the dynamic changes in land use and ecological risks during the transformation of this resource-based city. The land-use changes in Xuzhou in 2000, 2010, and 2020 were analyzed, using the Markov model and landscape-pattern indices, allowing an ecological risk-assessment model of land-use changes to be constructed. Additionally, the spatial heterogeneity of ecological risks was evaluated by using spatial autocorrelation. The results showed that urban expansion influenced land use in Xuzhou significantly. Owing to the rapid urban expansion, the area of extremely high-risk regions increased significantly in 2010. Furthermore, the subsidence areas caused by mining had profound impacts on the region’s ecology, and early interventions for ecological restoration are needed to prevent further deterioration. During the transformation, Xuzhou’s overall ecological risks reduced gradually, which was conducive to its transition into an ecological city.

The phase-change material (PCM) layer plays a critical role in governing the heat transfer characteristics of building walls. To evaluate this effect, two experimental test rooms with identical structural configurations were constructed and monitored under summer solar radiation conditions. One room incorporated an external phase-change mortar layer, whereas the other utilised a conventional, ordinary mortar layer wall to serve as a reference control. The heat transfer characteristics of the walls of both rooms were comprehensively evaluated under natural weather conditions. The experimental results indicate that, under the tested summer conditions, an external phase-change mortar layer with an appropriate phase-change temperature can improve the thermal regulation performance of the wall system. In particular, the wall incorporating PCM with a phase-change temperature of 32 °C effectively reduced the external surface temperature, with the maximum external surface temperature remaining below 44 °C. However, when the external surface temperature exceeds 44 °C, the PCM layer does not contribute to temperature reduction; instead, it may increase both the surface and overall wall temperatures due to ineffective phase change under mismatched thermal conditions. This study provides support for the engineering applications and parameter optimisation of phase-change thermal storage walls.