“…Some scholars only take a single city as the research object [Kassomenos et al, 2012 (Thessaloniki); Yotova et al, 2016 (Thessaloniki); Mohammed et al, 2018 (Kut City); Dang et al, 2021 (Beijing and Chengdu)], while others study small areas, such as the Estarreja area (Figueiredo et al, 2013), Rithala areas in India (Mishra et al, 2016), Thessaloniki area (Poupkou et al, 2011;Aleksandropoulou et al, 2012), Taiwan and Japan (Lu et al, 2018), and Taiwan Province (Chang et al, 2019). Other studies take the whole country as the object Yu et al, 2019;Wang et al, 2020;Zhou et al, 2020). Furthermore, Chang and Hu (2018) set up the G7 and BRICS as research objects, while Qian et al (2021) target major industrial sectors in China as research objects.…”