As regional interaction increases in an open economy, a region’s green total factor productivity in agriculture must be considered alongside relationships with other regions. In this study, the slack-based model (SBM) global Malmquist–Luenberger (GML) index is used to measure the green total factor productivity of agriculture in each province of China, and the social network analysis (SNA) and vector autoregressive model (VAR) impulse response function (IRF) are used to examine the spatial network structure and regional interactivity. The research confirms that the absolute value and concentration of agricultural green total factor productivity are generally higher in the south than in the north of China, but the peak is lower in the south than in the north. The network density of agricultural green total factor productivity in China from 2008 to 2019 shows an increase, with the cut-off values of mean, 10, 50, and 100 treated as 4.97%, 2.57%, 3.30%, and 2.43%, respectively. From 2008 to 2019, the central potentials of network entry and network exit of green total factor productivity in China’s agriculture show a “V”-shaped and inverted “V”-shaped evolution path, respectively, with the density of cohesive subgroups growing, which demonstrates that the spatial structure of green total factor productivity in Chinese agriculture has experienced an evolutionary path from polycentric to monocentric to polycentric conditions. The spatial interaction of different cohesive subgroups is intensifying and has a certain degree of self-stability. In terms of regional interaction, the siphon effect of the east on the green development of agriculture in the central and western regions is significant, but the trickle-down effect is not obvious, and the interaction between the central and western regions has a catalytic effect on the efficiency of the green economy of agriculture in both regions. It is recommended that targeted policies be introduced to support the flow of agricultural factors and industrial division of labour between the central and western regions and the south and north, taking into account the actual situation. The novelty of this paper is that it focuses on the green total factor productivity of Chinese agriculture and combines the innovative use of the social network analysis paradigm to analyse the green development of agriculture in a country from a spatial dynamic evolutionary perspective. A limitation of the research methodology in this paper is its poor applicability to closed economy analysis.

A more scientific green economy efficiency indicator is constructed based on OH (2010), and a multiperiod spatial DID model is used to examine the impact of national credit demonstration policies on urban green economy efficiency in a sample of cities above the prefecture level in the Yangtze River Delta. The study confirms the following: (1) The national credit demonstration policy makes a significant contribution to the green economic efficiency of cities, and it is conducive to strengthening awareness of the rule of law in the market to regulate market order. (2) The demand for credit regulation in coastal areas has increased under the new development pattern, and the national credit demonstration policy has effectively enhanced green economy efficiency through institutional supply. (3) Under the national credit demonstration policy, the subprovincial level and above can mobilise more resources for policy refinement and support, reducing transaction costs and improving the efficiency of the green economy. (4) The impact of the national credit demonstration policy on the efficiency of Zhejiang’s green economy is more obvious; but, under the overall framework of the Yangtze River Delta, the policy has a more prominent role in promoting green economy efficiency in other provinces. Policy insights are as follows: (1) Different cities have different degrees of impact on the efficiency of the green economy from the national credit demonstration policy, and they should implement differentiated measures based on regional heterogeneity; (2) regulating the use of administrative resources and avoiding undue administrative intervention are important prerequisites for promoting regional integration to enhance the efficiency of the green economy; and (3) strengthening interprovincial credit policy synergies can help to alleviate administrative distortions of policy implementation and enhance the efficiency of the regional green economy.

In order to solve the problem of integrated heat dissipation in electronic chips under continuous high-intensity operation and thus ensure their stable and normal operation, a novel bionic vapor chamber with a composite structure of leaf vein grooves is proposed. Leaf veins produce effective nutrient transport; however, how the wick core of the leaf vein groove porous composite structure affects heat transfer and flow in the vapor chamber remains elusive. In this study, the effects of the groove parameters, including the central groove diameter (D), the ratio of the inner and outer circle diameter (γ), and the number of grooves (N), on the temperature, velocity, and pressure distribution of the bionic vapor chamber were investigated based on a simplified numerical model. The results show that the maximum temperature difference at the condensing surface was reduced by approximately 50% as compared to the conventional vapor chamber, implying better temperature homogeneity. In addition, the heat and mass transfer performance of the vapor chamber improved as parameter γ increased. Moreover, the effects of variations in parameters N and D on the performance of the vapor chamber were competitive, with larger values of parameters N and D enhancing the heat transfer performance of the vapor chamber, and smaller parameter values reducing the flow pressure drop of the liquid. This provides a reference for research on the optimization of bionic vapor chambers.

As an important part of China’s ecological civilization, the impact of the Central Inspections of Environmental Protection (CIEP) on the development of a green economy has been widely recognized. This article uses the first round of the Central Inspections of Environmental Protection (CIEP) and the “look-back” in cities above the prefecture level in China’s Yangtze River Delta as a quasi-natural experiment to construct more scientific green economic efficiency indicators based on OH (2010), and employs a multi-period spatial DID (difference-in-differences) model to empirically investigate the impact of the CIEP on the urban green economic efficiency. This study confirms that: (1) The Central Inspections of Environmental Protection have a significant contribution to the green economic efficiency of cities, and the “look-back” is of great significance to the long-term green development of cities. (2) The Central Inspections of Environmental Protection have had a positive impact on the building of a pro-clear government–business relationship in coastal and riverine areas, promoting the application of green technology research and development, and, thus, improving the green economic efficiency of cities. (3) Under the constraints of the central environmental protection inspection system, the southern Jiangsu region has been effective in promoting the green transformation of enterprises to enhance the efficiency of the city’s green economy due to its location endowment and historical tradition of opening ports and trading in the late Qing Dynasty. (4) Under the pressure of environmental regulation, some enterprises chose to relocate their production to non-inspected areas, which had a negative spillover effect on the green economic efficiency of the cities they moved into. Policy Implications: The impact of central environmental inspections on the efficiency of urban green economies varies from time to time and place to place, and it is important to regulate the use of administrative resources and strengthen inter-provincial coordination to promote synergy and cooperation across provincial environmental inspection systems. This paper provides ideas for understanding the logical starting point for the implementation of the central environmental inspection system, and for better promoting the green transformation and high-quality development of regional economies based on national characteristics.

Ground source heat pumps (GSHPs), a high-efficiency and energy-saving air-conditioning technology that utilizes shallow geothermal resources for both heating and cooling, are a vital green energy system for residential and commercial buildings. Improving the performance of such a system was the focus of the current research. As soil temperature and thermal radius are two important aspects that affect the performance of ground source heat pump systems, we conducted a new numerical simulation to capture the changes in sensitive factors and propose the optimized paths. The numerical simulation analyzed the thermal characteristics of a borefield under different pre-cooling times and soil types. The results indicated the following: (1) The rate of the ground temperature change with pre-cooling during the discharging period had a faster rise than in the case without pre-cooling. The longer the precooling time was, the smaller the thermal radius became. In particular, when the precooling time was longer than 14 days, the decrease in the thermal radius rate percentages was less than 4%. (2) Among the three kinds of soils compared, the soils with lower thermal conductivity and thermal diffusivity best suppressed the thermal interference effects. (3) Using a multivariate nonlinear function regression model, a simulation formula was proposed to predict- the thermal radius, which considered the factors of thermal diffusivity, precooling time, and discharging time. The prediction deviation was within 14.8%.

Taking the Yangtze River Delta of China as a case study, the SBM model GML index is used to measure urban green total factor productivity (GTFP), green technical efficiency (EC) and green technological progress (TC) respectively, and the multi-period spatial DID method is applied to empirically demonstrate the long-term heterogeneous effects of the late Qing Dynasty's open port and trade policy on urban green economic efficiency. The study concludes that (1) the late Qing Dynasty's policy of opening ports for trade objectively increased the city's long-term green total factor productivity (GTFP) and green technical efficiency (EC), but had an insignificant effect on green technological progress (TC). (2) The Treaty of Shimonoseki was a watershed in the long-term impact of the port-opening and trading policy on green economic efficiency, with the port-opening and trading policy implemented before 1895 boosting urban GTFP and EC, and the port-opening and trading policy implemented after 1895 having a negative impact on urban GTFP, EC and TC. (3) Long-term GTFP, EC and TC were negatively affected by the opening of ports and trading policies in cities where the governors were based, while opening of ports and trading policies in cities where the governors were not based had a positive effect on long-term GTFP, EC and TC. (4) Western powers following the civil law tradition had a more prominent long-term impact on the green economic efficiency of economically invaded cities than did common law countries. This paper appropriately verifies the long-term impact of open history on a city's green economic efficiency, which is instructive for better understanding, formulating and improving foreign opening policies in the new era.