Ultramarine is a highly favored blue inorganic pigment. It is non-toxic with a deep color and widely used in architecture, plastics, coatings, fine arts and cosmetics. In this study, ultramarine pigment was synthesized using palygorskite, anhydrous sodium carbonate and sulfur as the raw materials through the high-temperature solid-phase method.
View Article and Find Full Text PDFDirect methanol fuel cells (DMFCs) have attracted increasing attention as a very promising and important energy source. In this paper, density functional theory (DFT) is used to study the structure and O-H fracture mechanism of methanol adsorption on PtCu (111) ( = 1, 2, 3) binary metal catalyst surfaces under different coverages. By comparing the adsorption energy and dehydrogenation energy barriers of methanol, it is found that the adsorption strength and dehydrogenation energy barriers of methanol on Pt and Cu sites decreased with increasing coverage.
View Article and Find Full Text PDFA large number of experiments show that PtCu catalyst has a good catalytic effect on methanol decomposition. Therefore, density functional theory (DFT) was used to further study the dehydrogenation of methanol catalyzed by PtCu (n = 1-3, m = 0-2). The energy diagrams of O-adsorption path and H-adsorption path were drawn.
View Article and Find Full Text PDFTo investigate the chemical constituents from Barringtonia racemosa, twelve compounds were isolated by chromatography methods and identified as 3β-p-E-coumaroymaslinic acid (1), cis-careaborin (2), careaborin (3), maslinic acid (4), 2α, 3β, 19α-trihydroxyolean-12-ene-24, 28-dioic acid (5), 3β-p-Z-coumaroylcorosolic acid (6), corosolic acid (7), 1α, 2α, 3β, 19α-tetrahydroxyurs-12-en-28-oic acid (8), 19α-hydroxyl ursolic acid (9), 3α, 19α-dihydroxyurs-12-en-24, 28-dioic acid (10), tormentic acid (11), 3-hydroxy-7, 22-dien-ergosterol(12) by the NMR and MS data analysis. Among them, compounds 1-4,7-12 were obtained from the genus Barringtonia for the first time. All the compounds didn't show nocytotoxic activity against MCF-7 and A549 cell lines (IC₅₀>50 mg•L⁻¹).
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