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As one of the important structures of composite materials, polymethacrylimide (PMI) foam sandwich structure is prone to debonding and delamination defects during manufacturing and service, which seriously affects the mechanical properties of materials. Therefore, it is necessary to detect the defects of foam sandwich structure. A linear frequency modulation infrared thermal wave nondestructive testing system was built to study the correlation between the geometric characteristics (diameter and depth) of the defect and the surface temperature signal and its influence on the detection effect. The image sequence is processed by principal component analysis, discrete Fourier transform, thermal wave signal reconstruction, and other algorithms. Studies have shown that the larger the defect diameter, the shallower the depth, easy to detect defects, detection effect is good. The detection system can effectively detect and identify debonding and de-lamination defects. The thermal wave signal reconstruction method is superior to the principal component analysis method and the discrete Fourier transform method in the signal-to-noise ratio index, which improves the quality of the image and is conducive to the effective identification of the image surface defect information.

Regioselective hydroesterification of alkenes and alkenylphenols was achieved utilizing CO2 as a CO source with the assistance of PMHS.

Synthesis of drug metabolites, which often have complex structures, is an integral step in the evaluation of drug candidate metabolism, pharmacokinetic (PK) properties, and safety profiles. Frequently, such synthetic endeavors entail arduous, multiple-step de novo synthetic routes. Herein, we present the one-step Shono-type electrochemical synthesis of milligrams of chiral α-hydroxyl amide metabolites of two orexin receptor antagonists, MK-8133 and MK-6096, as revealed by a small-scale (pico- to nano-mole level) reaction screening using a lab-built online electrochemistry (EC)/mass spectrometry (MS) (EC/MS) platform. The electrochemical oxidation of MK-8133 and MK-6096 was conducted in aqueous media and found to produce the corresponding α-piperidinols with exclusive regio- and stereoselectivity, as confirmed by high-resolution nuclear magnetic resonance (NMR) characterization of products. Based on density functional theory (DFT) calculations, the exceptional regio- and stereoselectivity for this electrochemical oxidation are governed by more favorable energetics of the transition state, leading to the preferred secondary carbon radical α to the amide group and subsequent steric hindrance associated with the U-shaped conformation of the cation derived from the secondary α-carbon radical, respectively.

The newly identified Neoproterozoic Yuanmou high-Nb mafic and adakitic rocks at the western margin of the Yangtze Block in South China are investigated for petrogenesis and geodynamic implications. Zircon U-Pb ages show the adakitic granodiorite host and mafic microgranular enclaves (MMEs) were synchronously emplaced at 811−806 Ma, and were cut by an 802 ± 11.5 Ma mafic dike. The medium-grained granodiorites consist mainly of plagioclase, quartz, K-felspar, biotite, and amphibole. High SiO2 (62.8−67.5 wt%), Al2O3 (13.1−16.8 wt%) contents, high Sr/Y (17.4−49.0), and (La/Yb)N (16.3−52.6) but low Y (6.83−16.1 ppm) and Yb (0.74−1.82 ppm) concentrations of the granodiorites point toward their calc-alkaline and adakitic nature. Further, their high Dy/Yb (1.52−2.31) and Gd/Y (2.35−4.43) and low K2O/Na2O (0.22−0.48) and Th/La (0.14−0.20) ratios, constant bulk rock εNd(t) (−0.5 to −1.5) and zircon εHf(t) (0.0 to +2.3) values, suggest that the granodiorites were derived from partial melting of a mafic lower crustal source. The MMEs in the granodiorites and mafic dike intrusions are composed of amphibole, plagioclase, clinopyroxene, and olivine, and have similar chemical compositions, such as high Nb (15.7−41.9 ppm) and TiO2 (2.13−3.39 wt%) contents and high Nb/U (18.7−30.9) values, akin to alkaline high-Nb basalts (HNB). Their variable Ba/Nb (7.68−79.2), Nb/Zr (0.09−0.16), high Nb/Th (5.47−6.68), and low Th/Zr (0.01−0.03) and La/Nb (1.03−1.37) ratios indicate a mantle source modified by melts derived from subducted oceanic crust and sediments. The Yuanmou HNB with high εNd(t) (+4.8 to +6.9) were probably generated during back-arc extension by decompression melting of a mantle source metasomatized by adakitic slab melts formed during earlier stages of the subduction. This implies that the location of the back-arc was far from the subducted oceanic slab, possibly due to a slab rollback process. In this scenario, HNB intrusions provided the heat for partial melting and adakitic melt formation in the mafic lower crust. The model suggests that the Yuanmou and other similar associations of HNBs and adakitic rocks emplaced along the western margin of the Yangtze Block are products of a widespread Neoproterozoic back-arc extension.

Anthocyanins play a critical role in flower colour pattern formation, and their biosynthesis is typically regulated by transcription factors (TFs). Curcuma alismatifolia is a well-known ornamental plant with colourful flowers. However, little is known about the genes that regulate anthocyanin accumulation in C. alismatifolia. In the present study, high-quality RNA was extracted from three flowering stages of ‘Dutch Red’ and the blossoming stage of ‘Chocolate’. In all, 576.45 Mb clean data and 159,687 de-redundant sequences were captured. The Kyoto Encyclopedia of Genes and Genomes analysis showed that the pathways of phenylpropanoid biosynthesis, flavonoid biosynthesis, flavone and flavonol biosynthesis, and terpenoid backbone biosynthesis were the most enriched. Thirty unique isoforms were annotated as encoding enzymes or TFs involved in anthocyanin biosynthesis. Further analysis showed that the up-regulation of anthocyanin biosynthesis genes was associated with the red colour formation of ‘Dutch Red’, and their expression was induced at the initial flowering stage. The gene flavonoid 3′, 5′-hydroxylase, a key enzyme in the formation of delphinidin-based anthocyanins, reduced expression in ‘Chocolate’. In addition, we identified totally 14 TFs including 11 MYB proteins and 3 WD proteins, which might play important roles in the regulation of anthocyanin biosynthesis. The quantitative Real-Time Polymerase Chain Reaction (qRT-PCR) results were generally consistent with the high-throughput sequencing results. Together, the results of our study provide a valuable resource for the regulatory mechanism of anthocyanin biosynthesis in C. alismatifolia and for the breeding of Curcuma cultivars with novel and charming flower colours.