A 10-m national-scale map of ground-mounted photovoltaic power stations in China of 2020.

We provide a remote sensing derived dataset for large-scale ground-mounted photovoltaic (PV) power stations in China of 2020, which has high spatial resolution of 10 meters. The dataset is based on the Google Earth Engine (GEE) cloud computing platform via random forest classifier and active learning strategy. Specifically, ground samples are carefully collected across China via both field survey and visual interpretation. Afterwards, spectral and texture features are calculated from publicly available Sentinel-2 imagery. Meanwhile, topographic features consisting of slope and aspect that are sensitive to PV locations are also included, aiming to construct a multi-dimensional and discriminative feature space. Finally, the trained random forest model is adopted to predict PV power stations of China parallelly on GEE. Technical validation has been carefully performed across China which achieved a satisfactory accuracy over 89%. Above all, as the first publicly released 10-m national-scale distribution dataset of China's ground-mounted PV power stations, it can provide data references for relevant researchers in fields such as energy, land, remote sensing and environmental sciences.

First-Principles Study on the Nanofriction Properties of Diamane: The Thinnest Diamond Film.

Diamane, the thinnest sp3-hybridized diamond film, has attracted great interest due to its excellent mechanical, electronic, and thermal properties inherited from both graphene and diamond. In this study, the friction properties of surface hydrogenated and fluorinated diamane (H- and F-diamane) are investigated with dispersion-corrected density functional theory (DFT) calculations for the first time. Our calculations show that the F-diamane exhibits approximately equal friction to graphene, despite the presence of morphological corrugation induced by sp3 hybridization. Comparative studies have found that the coefficient of friction of H-diamane is about twice that of F-diamane, although they have the same surface geometric folds. These results are attributed to the packed charge surface of F-diamane, which can not only effectively shield carbon interactions from two contacting films, but also provide strong electron-electron repulsive interaction, resulting in a large interlayer distance and a small wrinkle of potential energy at the interface. The interesting results obtained in this study have enriched our understanding of the tribological properties of diamane, and are the tribological basis for the design and application of diamane in nanodevices.