Synergetic development is the basis and means for the sustainable development of regional economies. Research on the synergetic economic relationship between cities and the exposure of the internal structure and evolution mechanisms of the Urban Economic Synergetic Development Network (UESDN) in the context of industrial agglomeration promote the construction and sustainable development of such a system. Industrial agglomeration not only affects the spatial distribution of industrial structures and enterprise activities but also causes differences in city positions. Using input–output theory, this study constructed a UESDN for China in 2005, 2010, and 2015, and employed social-network analysis to analyze the spatial and temporal evolution characteristics of China’s synergetic development pattern. The degree centrality, betweenness centrality, and cohesive subgroups of the UESDN were computed using models in complex-network theory. This study found that the synergetic development pattern of Chinese urban economies has gradually developed from the hub-spoke model focused on Eastern provincial capitals to the network model of eastern and central cities over the period of 2005–2015. A few key cities act as intermediaries that carry economic factors with the shortest path in the UESDN. The Yangtze River economic belt, the axis belt of the Eastern coast and that of the Western economic belt were gradually formed. The number and strength of the correlation between cities within the subgroups have also continually increased. In our conclusion, we offer some suggestions for establishing a system of synergetic development between cities to improve urbanization levels.

Due to growing concerns for environmental problems and food quality, consumers pay more attention to the carbon emission and freshness of fresh food. The booming e-commerce also accelerates the development of the dual-channel supply chain. In the dual-channel supply chain of fresh food, the carbon emission and freshness of fresh food are becoming important factors affecting consumers’ purchase demand. This paper focuses on the optimal decision of carbon emission reduction and pricing, which is investigated by a Stackelberg game-theoretic approach in three dual-channel supply chain sales models (retailer dual channel, producer dual channel, and mixed dual channel). A two-stage fresh food supply chain system composed of a producer and a retailer is explored. The sensitivity analysis and the comparison of three dual-channel models are carried out. The results show the following: (1) the sales price, carbon emission reduction, market demand, producer’s profit, retailer’s profit, and supply chain’s profit of fresh food under the three dual-channel supply chains show the same change on different levels of consumers’ low-carbon preference coefficient and freshness level, respectively; (2) the optimal decision of carbon emission reduction and pricing, demand, and profit of the three dual-channel models need to be determined according to the value of consumers’ purchasing preferences for the retailer’s offline channel. The paper gives some enlightenment to the decision-making members in the fresh dual-channel supply chain.