Under the strategy of digital technology development and rural revitalisation, the digital economy has gradually become a powerful engine for rural revitalisation and development. Based on the coupling coordination mechanism of digital economy and rural revitalisation, this paper constructs the index evaluation system of digital economy and rural revitalisation and empirically studies the development characteristics of digital economy and rural revitalisation by using the coupling coordination degree and grey relation model. The results show that during 2016–2020, the overall development level of digital economy and rural revitalisation in China is high in the East and low in the West. The coupling coordination between digital economy and rural revitalisation has significant regional differences and a downward trend, and the coupling coordination degree is positively correlated. The empirical results of the grey correlation model show that the number of postal employees and per capital grain production are the most important potential factors affecting digital economy and rural revitalisation, respectively. Finally, it is suggested that the government should continue to increase investment in science, technology, and agriculture, accelerate the project of cultivating high-level scientific and technological innovation and rural management talents, and strengthen regional cooperation and collaboration.

Green technology innovation offers a new dynamic support and realization path for the comprehensive transformation and upgrading of the digital economy and intensive development mode. The study of green technology’s coupled and coordinated development and evolution with the digital economy is conducive to promoting the quality and efficiency of the digital economy. With the aid of the coupling coordination degree, nuclear density, and the Gini coefficient, this paper develops a digital economy and green technology innovation evaluation index system based on the theoretical mechanism of coupling and coordination and empirically investigates the spatial and temporal evolution of the dynamic coupling and coordination of the digital economy and green technology innovation in Chinese regions from 2011 to 2021. The results show that there is an imbalance in the coupled and coordinated development of the regional digital economy and green technology innovation, and the overall strength needs to be improved; the empirical results of nuclear density show that the regional development gap is further revealed, and the driving mechanism needs to be optimized; the empirical results of Gini coefficient show that there are obvious differences in contribution rates between regions, and the coordination and collaboration mechanism needs to be improved. Finally, it is suggested that, in the future, green technology innovation capabilities should be comprehensively promoted, regional digital development drive mechanisms should be optimized, inter-regional coordination and regulatory mechanisms should be improved, and the coupled and coordinated development of the digital economy and green technology innovation at a higher level should be realized as soon as possible.

Most developed countries in the world are maritime powers. This article constructs an ecological efficiency evaluation system based on the characteristics of the ocean itself while taking into account the relationship between land and sea. Based on social network analysis, the relationship between China’s marine ecological efficiency is regarded as a social network system, and the roles and positions played by 11 coastal cities in the network are analyzed from a relational perspective. Next, based on the unexpected super efficiency model to measure the ocean efficiency value in China’s coastal areas, we explore its spatiotemporal evolution characteristics, and measure the ocean ecological efficiency while incorporating ecological environmental pollution as an unexpected output into the evaluation system. Then, the spatial incidence matrix of marine ecological efficiency is calculated through the modified gravity model, and the characteristics of network structure are described with the help of the social network method. In addition, ArcGIS software is used to visualize the spatial evolution process. Finally, QAP regression is used to explore the key factors affecting the spatial correlation network of marine ecological efficiency in China. The results show the following: (1) In terms of time, the marine eco-efficiency of most provinces is not high, and the difference between provinces is obvious, but on the whole, it shows a fluctuating upward trend. (2) From the perspective of space, the overall displacement of the center of marine eco-efficiency in China is large in the north–south direction and small in the east–west direction, and the center of marine eco-efficiency is always concentrated near the Yangtze River Delta. (3) On the whole, the spatial correlation network of China’s marine eco-efficiency is becoming more and more complex. The number of correlation relationships and network density is increasing, and the network framework is gradually maturing. The spatial adjacency matrix, the difference in economic development level, and the difference in population distribution level can significantly promote the formation and development of the spatial correlation network of marine eco-efficiency. However, the differences in the level of opening to the outside world and in the structure of marine industries restrain their spatial networks. The difference between marine science and technology levels is not significant.

[Purpose] To explore the coupling coordination evolution law of China’s agricultural ecological environment and economic development, and provide reference and a decision-making basis for coordinating the relationship between the ecological environment and agricultural economy in the process of China’s agricultural economic development. [Method] Based on the coupling coordination mechanism between ecological protection and agricultural economy, this paper constructs an evaluation index system for agricultural ecological environment and economic growth, and explores the spatiotemporal evolution law of the coupling coordination between the agricultural ecological economic system in China’s 31 province administrative regions from 2010 to 2020. [Result] From 2010 to 2020, the overall development level of China’s agricultural ecology and economy was gradually improving; the level of coupling coordination increased significantly before 2015, but then the growth remained stable; the global Moran’s I index of coordination is “first descending and then ascending”; and the LISA cluster diagram of the local Moran’s I index was “east high and west low” before 2015, but then “west high and east low”. [Conclusions] The level of coupling and coordination development of agricultural ecological economic systems in various provinces has steadily increased, but the development level between regions is uneven. It is necessary to strengthen natural disaster management, increase investment in agricultural development, and enhance regional cooperation between regions to promote high-quality and green sustainable development of agricultural ecological economic systems. [Innovation] A new evaluation index system was constructed, the indicator data are complete and comprehensive (including data from 31 different province administrative regions from 2010 to 2020), and the analysis perspective is rich and diverse (through the comparison and changes of the time and space perspectives, the results from different perspectives were comprehensively analyzed). This paper finds that the coordination degree shows significant periodicity with 2015 as the boundary; the growth rate is “west fast and east slow”.