A vertical greening system is becoming increasingly crucial in resolving the energy crisis and environmental problems in a sustainable ecosystem. Researchers have conducted a comprehensive study on vertical greening systems from technology, functional and architectural perspectives. These include ecological, economic and social functions. Most of the current studies emphasize the benefits of vertical greening systems to the environment, while vertical greening technology and its socio-economic benefits receive insufficient attention. In order to study the vertical greening field in depth, this paper comprehensively and systematically summarizes vertical greening technology and functions. Meanwhile, based on the Web of Science (WOS), CiteSpace was used to analyze the relevant literature in the vertical greening field from 2012 to 2022, to explore the hot spots, development status and future trends of vertical greening technology, and to build a knowledge map in the vertical greening field. The research shows that as a low impact development technology, the vertical greening system has received the most extensive attention in the past few years. Air quality, microclimate regulation and energy have always been the focus and hot issues of people’s attention. The future research directions are cooling effect, active system and indoor space. This study is aimed at promoting the future development of vertical greening system technology and providing reference and direction for researchers, planners and developers, as well as individuals interested in future urban and rural planning.

${\mathrm{Al}}_2{\mathrm{O}}_3$ -doped ${\mathrm{La}}_{0.7}{\mathrm{Sr}}_{0.3}{\mathrm{MnO}}_3\left({\mathrm{Al}}_2{\mathrm{O}}_3\text{-}\mathrm{LSMO}\right)$ thin films were deposited on $\mathrm{Si}\left(111\right)$ substrate via a pulsed laser deposition. The deposited ${\mathrm{Al}}_2{\mathrm{O}}_3\text{-}\mathrm{LSMO}$ composite thin films were characterized by x-ray diffraction, scanning electron microscopy, and electro- and magneto-transport measurements. The main phase in the ${\mathrm{Al}}_2{\mathrm{O}}_3\text{-}\mathrm{LSMO}$ composite films was the perovskite phase. Texturelike microstructure was observed in the ${\mathrm{Al}}_2{\mathrm{O}}_3\text{-}\mathrm{LSMO}$ composite films while the average grain size remained almost unchanged compared to the pure samples. The metal-insulator transition temperature decreased as a result of the addition of ${\mathrm{Al}}_2{\mathrm{O}}_3$ and further reduced with increasing ${\mathrm{Al}}_2{\mathrm{O}}_3$ content. A maximum low field mangetoresistance of $\sim 15\%$ was achieved in the $2∕20{\mathrm{Al}}_2{\mathrm{O}}_3\text{-}\mathrm{LSMO}$ thin films, which could be well explained in terms of the grain boundary tunneling effect. The composition of the composite thin films can be easily tuned by adjusting the target composition. This method is believed to be applicable to exploring the combinations of other manganites and insulators.

An ideal artificial bone implant should have similar mechanical properties and biocompatibility to natural bone, as well as an internal structure that facilitates stomatal penetration. In this work, 3D printing was used to fabricate and investigate artificial bone composites based on HA-ZrO₂-PVA. The composites were proportionally configured using zirconia (ZrO₂), hydroxyapatite (HA) and polyvinyl alcohol (PVA), where the ZrO₂ played a toughening role and PVA solution served as a binder. In order to obtain the optimal 3D printing process parameters for the composites, a theoretical model of the extrusion process of the composites was first established, followed by the optimization of various parameters including the spray head internal diameter, extrusion pressure, extrusion speed, and extrusion line width. The results showed that, at the optimum parameters of a spray head diameter of 0.2 mm, extrusion pressure values ranging from 1–3 bar, a line spacing of 0.8–1.5 mm, and a spray head displacement range of 8–10 mm/s, a better structure of biological bone scaffolds could be obtained. The mechanical tests performed on the scaffolds showed that the elastic modulus of the artificial bone scaffolds reached about 174 MPa, which fulfilled the biomechanical requirements of human bone. According to scanning electron microscope observation of the scaffold sample, the porosity of the scaffold sample was close to 65%, which can well promote the growth of chondrocytes and angiogenesis. In addition, c5.18 chondrocytes were used to verify the biocompatibility of the composite materials, and the cell proliferation was increased by 100% when compared with that of the control group. The results showed that the composite has good biocompatibility.