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[Display omitted] • The Au NCs modified BiOBr catalyst was successfully applied to photocatalytic CO 2 reduction. • The Au active sites improve charge separation and transfer efficiency. • The Au active sites can effectively enhance the selectivity and activity of catalyst. The selectivity and activity of photocatalytic CO 2 reduction can be effectively enhanced by modulating the reduction pathway of CO 2 molecules and promoting the separation of photogenerated charges. Here, we synthesized an Au nanoclusters (Au NCs) modified BiOBr nanosheets catalyst with highly exposed Au active sites by liquid nitrogen assisted ionothermal method. Compared with the pristine BiOBr, the 2.0 wt% Au 25 NCs/BiOBr showed excellent photocatalytic activity with a nearly double increase in the rate of CO emission (43.57 μmol g−1h−1). Through relevant experimental characterizations and density functional theory (DFT) calculations, it had been proved that the increased CO 2 reduction activities of the samples are attributed to the Au active sites. The increase of Au active sites lowered the CO 2 thermodynamic reaction energy barrier and also changed the reaction pathways. This work will play a positive role in application of Au NCs catalysts in photocatalytic applications in the further. [ABSTRACT FROM AUTHOR]

This paper introduces an astronomical image alignment algorithm. This algorithm uses the means of the rows and columns of the original image for alignment, and finds the optimal offset corresponding to the maximum similarity by comparing different offsets between images. The similarity is evaluated by the standard deviation of the quotient divided by the means. This paper also discusses the theoretical feasibility of this algorithm. Through practical testing, it has been confirmed that the algorithm is fast and robust. • This work introduces a very simple, fast, and robust image align algorithm. [ABSTRACT FROM AUTHOR]

Enhancing charge separation in semiconductor photocatalysts is a major challenge for efficient artificial photosynthesis. Herein, a compact heterojunction is designed by embedding half‐metallic C(CN)3 (hm‐CN) hydrothermally in BiOBr (BOB) as the backbone. The interface between hm‐CN and BOB is seamless and formed by covalent bonding to facilitate the transmission of photoinduced electrons from BOB to hm‐CN. The transient photocurrents and electrochemical impedance spectra reveal that the modified composite catalyst exhibits a larger electron transfer rate. The photocatalytic activity of hm‐CN/BOB increases significantly as indicated by a CO yield that is about four times higher than that of individual components. Density‐functional theory calculations verify that the heterojunction improves electron transport and decreases the reaction energy barrier, thus promoting the overall photocatalytic CO2 conversion efficiency. The half‐metal nitride coupled semiconductor heterojunctions might have large potential in artificial photosynthesis and related applications. [ABSTRACT FROM AUTHOR]

Water pollution is a significant social issue that endangers human health. The technology for the photocatalytic degradation of organic pollutants in water can directly utilize solar energy and has a promising future. A novel Co3O4/g-C3N4 type-II heterojunction material was prepared by hydrothermal and calcination strategies and used for the economical photocatalytic degradation of rhodamine B (RhB) in water. Benefitting the development of type-II heterojunction structure, the separation and transfer of photogenerated electrons and holes in 5% Co3O4/g-C3N4 photocatalyst was accelerated, leading to a degradation rate 5.8 times higher than that of pure g-C3N4. The radical capturing experiments and ESR spectra indicated that the main active species are •O2− and h+. This work will provide possible routes for exploring catalysts with potential for photocatalytic applications. [ABSTRACT FROM AUTHOR]

We present the Photometric Auxiliary System (PAS) attached to the 25-cm Photometric Telescope (PT) at Xinglong Observatory of National Astronomical Observatories, Chinese Academy of Sciences (NAOC). This PAS can provide real-time atmospheric extinction for other telescopes at the same station for flux calibration via observing standard stars, e.g. the 2.16-m reflector and 1-m telescope. Moreover, the real-time atmospheric extinction could act as a useful reference for other local telescopes regarding the adjustment of observing strategies, such as changing the exposure time, which is important for the observers. This PAS has been operated since February 2012, and we have obtained the r -band atmospheric extinction of Xinglong Observatory from February 2012 to March 2018. With these data, we have analyzed the atmospheric extinction of Xinglong Observatory in detail. [ABSTRACT FROM AUTHOR]