At the invitation of Professor Yang Yongchun from the School of Earth and Environmental Sciences, Lanzhou University and the Key Laboratory of Western China's Environmental Systems, Ministry of Education, China, Professor Xu Wei from the University of Lethbridge, Canada, visited Room 1615, Guanyun Building, Chengguan Campus of Lanzhou University on June 2, 2026, for an academic visit and exchange.

Professor Xu Wei delivered an academic presentation titled "Effects of Digital Economy on Carbon Emission Intensity in Chinese Cities: A Life-Cycle Theory and the Application of Non-Linear Spatial Panel Smooth Transition Threshold Model". Based on the technology life-cycle theory, Professor Xu constructed a theoretical framework for the relationship between the development of the digital economy and carbon emission intensity, noting that their relationship was not simply linear but exhibited distinct nonlinear characteristics and spatial spillover effects, accompanied by turning points. By applying the non-linear spatial panel smooth transition threshold model, Professor Xu empirically found that, for 271 prefecture-level cities in China from 2011 to 2019, the direct effect of the digital economy on carbon emission intensity followed an inverted U-shaped nonlinear pattern—first rising, then declining after crossing the turning point. Meanwhile, the spatial spillover effect of the digital economy on carbon emission intensity was also nonlinear and exhibited a U-shaped characteristic. Both effects showed heterogeneity across different types of industrial structures. Although the development of the digital economy could promote carbon emission reduction and efficiency improvement in old industrial bases, this effect was not yet significant in resource-based economic regions. These findings provided important references for the application of digital technology and carbon emission governance in China.

The entire presentation was both profound and accessible, combining theoretical height with close relevance to practical issues, and was warmly received by the attending faculty and students. After the presentation, faculty and students engaged in lively discussions and in-depth exchanges on the presentation content, academic questions, future development, and other aspects, effectively fostering academic interaction and intellectual exchange in fields such as geography, economics, and ecology, and laying a solid foundation for further advancing international collaborative research.