It has been a vital topic for speeding up a high integration of the digital economy and green economic transformation in China's academic and social domains. This paper, based on 2005 to 2020 data of China's 280 cities, uses principal component analysis and non-expected output super-efficiency EBM model to measure cities' digital economic level and green economic efficiency and studies the impacts and mechanism of digital economic development on urban green economic efficiency in consideration of endogeneity and robustness. It concludes that digital economy can effectively improve urban green economic efficiency, and enforce the green economic diffusion effects of middle or large cities over their surrounding cities, which overcomes the echo effect over small cities, helping fulfill network effect which turning “core-periphery” structure by displaying green universal welfare functions on differently sized cities and boosting regional green economy. Improvement of digital economy on green economic efficiency is more where has a higher marketizing level and environmental regulations. Digital economy can promote green innovation and economic agglomeration, driving urban low-carbon growth. This paper presents suggestions for governments on raising support for digital industries, on making differentiated function positioning and strategies for differently sized cities, and on creating a sound marketing and policy environment for an entire green transformation.

Abstract: This paper selects appropriate indexes and uses principal component analysis to evaluate Jiangsu's countylevel urbanization and industrialization level, and uses correlation to analyze their coordination between Jiangsu's rural industrialization and rural urbanization with result showing a higher level of rural industrialization level, a bigger regional variance, a lower nonrural population in rural area. Jiangsu's countylevel industrialization is highly positive to urbanization. Their coordinated development has a larger regional variance. This paper presents suggestions in improving rural urbanization quality in southern Jiangsu, in boosting industrialization progress in northern Jiangsu, and in advancing their industrial linking development.

This paper, via multiple linear regress analysis, studies the relation between Tailu lake water environment and GDP increase, gross industrial production, gross agricultural production in Wuxi city during 1987-2003, concludes that the Tailu lake environment is closely interrelated to population growth and industrial structural changes. The water pollution is chiefly derived from agricultural organic pollution, living water and industrial water-gas-solid wastes. This paper gives some suggestions to improve the Tailu lake water environment.