In this paper, sodium citrate was selected as a shape inducer to construct a multi-interface embroidered spherical structure. The RL _min value is −45.6 dB and the EAB at 2.6 mm is 6.08 GHz, owing to the mutual balance of impedance and attenuation.

It is of significant importance to conduct research on the relationship between urbanization and eco-efficiency (EE), for it can aid policy making for urban and regional sustainable development. This paper studied the effects of urbanization on the EE in 30 provinces of China from 2008 to 2019. Using the epsilon-based measure (EBM) model with undesirable outputs, this study measured the EE of China’s provinces before empirically analyzing the effects of urbanization on EE. Conclusions could be drawn: the annual mean EE of the eastern region was the highest (0.837), followed by those of the central region (0.653) and western region (0.570), and that of the northeast region remained the lowest (0.438). Zooming into the provinces and cities, the EEs of Beijing, Shanghai, and Fujian were at the production frontier surface, with a high level of EE during the study period, while those of Gansu, Ningxia, and Xinjiang were generally at a lower level. Empirical analysis showed that the effects of urbanization on EE in China presented a U-shaped relationship, having a negative correlation first and then reversing to a positive one. At present, China is in the early negative stage, and the turning point has yet to come. Considering the control variables, the economic development level, technological progress, and foreign direct investment have positively influenced eco-efficiency. Overall, the paper may shed light on related studies and provide relevant policy suggestions to promote EE through a new urbanization strategy.