Core-shell engineered g-C3N4@ NaNbO3for enhancing photocatalytic reduction of CO2.

Photocatalytic reduction of carbon dioxide is a technology that effectively utilizes CO2and solar energy. Sodium niobate (NaNbO3) has received much attention in the field of photocatalysis due to its excellent photocatalytic properties. However, the application of NaNbO3in the field of photocatalysis is still limited by poor reaction to visible light and easy recombination of photo-generated carriers. Heterojunction with g-C3N4to construct core-shell structure can effectively improve the above problems. Combining the two can design a core-shell composite material that is beneficial for photocatalytic reduction of CO2. Herein, we prepared a core-shell heterojunction g-C3N4/NaNbO3by uniformly impregnating urea on the surface of NaNbO3chromium nanofibers with NaNbO3nanofibers prepared by electrospinning as a catalyst carrier, and urea as a precursor of g-C3N4. The core-shell structure of g-C3N4/NaNbO3was verified by a series of characterization methods such as XPS, XRD, and TEM. It was found that under the same conditions, the methanol yield of core-shell g-C3N4/NaNbO3was 12.86µmol·g-1·h-1, which is twice that of pure NaNbO3(6.67µmol·g-1·h-1). This article highlights an impregnation method to build core-shell structures for improved photocatalytic reduction of CO2.

Selective Synthesis of Alkynylated Isoquinolines and Biisoquinolines via RhIII Catalyzed C-H Activation/1,3-Diyne Strategy.

Described herein is a convenient and highly selective synthesis of alkynylated isoquinolines and biisoquinolines from various aryl ketone O-pivaloyloxime derivatives and 1,3-diynes via rhodium-catalyzed C-H bond activation. In this transformations, alkynylated isoquinolines, 3,4'- and 3,3'-biisoquinolines could be obtained respectively through changing the reaction conditions. Mechanistic investigation revealed that the C-H activation of aryl ketone O-pivaloyloxime was the key step to this reaction.

Enwrapping g-C3N4 on In2O3 hollow hexagonal tubular for photocatalytic CO2 conversion: Construction, characterization, and Z-scheme mechanism insight.

The reduction of CO2 achieved by photocatalysis can simultaneously alleviate the energy crisis and solve environmental issues. Nevertheless, it remains challenging for the rational design of photocatalysts with high-efficiency carrier migration ability. Herein, the Z-scheme g-C3N4/In2O3 (CN/INO) heterostructure was fabricated via metal-organic frameworks (MOFs) assisted thermal deposition which could form a fully encapsulated hollow tubular structure. The unique structure was based on the MOFs-derived hollow hexagonal In2O3 tubular integrated with ultrathin g-C3N4. The Z-scheme CN/INO heterojunction exhibited a larger specific surface area and excellent charge separation efficiency. Benefiting from the above features, the Z-scheme CN/INO heterojunction demonstrated superior performance on photocatalytic CO2 reduction. The formation of CO and CH3OH over the optimized CN/INO-2 catalyst was 7.94 and 1.44 µmol⋅g-1⋅h-1, respectively. Moreover, the density functional theory (DFT) calculations and Kelvin probe force microscopy (KPFM) was carried out to further investigate the situation of charge transfer on the interface of CN/INO. The in-situ Fourier transform infrared spectroscopy (FTIR) was measured to confirm the immediate products and the possible mechanism of photocatalytic CO2 reduction was proposed. This work provided a MOFs-assisted strategy to construct a Z-scheme system for photocatalytic CO2 reduction.

A new method for cylindricity error evaluation based on increment-simplex algorithm.

A geometric error determines the quality and function of a product to a certain extent. Cylindricity error is an important indicator of the geometric error of form parts. In recent years, with the development of geometric product verification and specification (GPS), the specification of the cylindricity error and high-precision detection have become the focus in the field of industrial metrology. In this paper, by analyzing the existing cylindricity evaluation strategy, a new method for cylindricity error evaluation based on increment-simplex algorithm is proposed. The purpose is to improve the efficiency of cylindricity error analysis on the basis of ensuring the accuracy requirements. First, according to the GPS specification, the characteristics and applications of the circular section method, the helicoid line method, the generatrix line method, and the bird-cage method for the extraction operation are analyzed. And for the fitting operation, the mathematical models of the cylindricity fitting for the least squares cylinder, minimum circumscribed cylinder, maximum inscribed cylinder, and minimum zone cylinder in cartesian and cylindrical coordinate systems are constructed. Second, a new method of cylindricity error optimization evaluation based on the incremental optimization method is proposed. A theoretical analysis of the new method is made with the circular section method as an example, and the specific steps of cylindricity error analysis based on the circular section method of the new method are given. Finally, experiments and analysis are carried out, and the accuracies and evaluation efficiencies of the cylindricity error of the different cylindricity measurement and evaluation strategies are compared and analyzed. The results and operating efficiency of the increment-simplex algorithm and the traditional algorithms are compared, and the effectiveness and feasibility of the new method are proved.

Identification and Expression Analysis of Tryptophan Hydroxylase in the Brain and Ventral Nerve Cord of Ragworm Neanthes japonica (Polychaeta, Annelida).

Tryptophan hydroxylase (TPH) was stained in the central nervous system of the Neanthes japonica (Polychaeta, Annelida), using sheep anti-tryptophan hydroxylase antibody by the Streptavidin-Peroxidase immunohistochemical method and Colophony-Paraffin embedded section technique. The immunohistochemistry results revealed that the TPH is distributed in the brain and ventral nerve cord, which is consistent with that of serotonin (5-hydroxytryptamine, 5-HT) that labeled by anti-serotonin antibody. Using the rapid amplification of cDNA ends (RACE) technique, TPH cDNA cloned from Neanthes japonica's central nervous system was 1778bp, which encodes predicted protein of 463 amino acid residues. The co-localization of TPH and 5-HT indicated that the specific TPH was responsible for the central serotonin synthesis in the central nervous system of annelida, TPH and 5-HT not only could be as the novel mutual corroboration marker to detect serotonergic neurons, but also provides the evidences for the evolution of aromatic amino acid hydroxylase genes. Anat Rec, 300:415-424, 2017. © 2016 Wiley Periodicals, Inc.