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In this work, chromium coating conducted by magnetron sputtering was introduced to braze SiC ceramics using inactive AgCu filler metal. The results showed that reliable metallurgical bonding of SiC ceramics was obtained at 900°C for 10 minutes. SEM, XRD, and TEM were used to identify the reaction phase in the joint, and the typical interfacial microstructure was SiC/mixed CrSi2 + Cr23C6 layer/CrSi2/Ag(s,s)+Cu(s,s)/CrSi2/mixed CrSi2 + Cr23C6 layer/SiC. The shear strength of SiC joint using chromium coating brazed with inactive AgCu filler metal was 29.6 MPa and the joint fractured at the SiC substrate entirely after shear test. The proposed active element coating method provides a feasible way to achieve the brazing of ceramics. [ABSTRACT FROM AUTHOR]

High‐optical‐quality ternary [(Y1‐xGdx)0.99Dy0.01]2O3 (x = 0 and 0.4) ceramics were successfully fabricated by vacuum sintering with in‐line transmittances of 71.4%‐75.1% at 574 nm, the wavelength of Dy3+ emission (the 4F9/2 → 6H13/2 transition). Substitution of Gd3+ for Y3+ significantly affected the photoluminescent and scintillant properties of the ceramics. Gd3+ addition effectively increased lattice parameters and theoretical densities of the ceramic samples; this contributed to enhanced X‐ray absorption coefficients. Both [(Y1‐xGdx)0.99Dy0.01]2O3 (x = 0 and 0.4) ceramics displayed typical Dy3+ emissions from 4F9/2 → 6HJ (J = 15/2, 13/2, 11/2) transitions under UV and X‐ray irradiations. By incorporating Gd3+ into the lattice, a stronger excitation peak of Gd3+ due to internal f‐f transitions relative to Dy3+ was observed at 276 nm; subsequent ceramics obtained a sharper PL intensity and a warmer hue via effective energy transfer from Gd3+ to Dy3+. Using a Gd3+ dopant generally reduces the total photoluminescence/photoluminescence excitation intensities and light output; it also delays the lifetime and afterglow of the transparent ceramics. [ABSTRACT FROM AUTHOR]

The natural volatile oil has high medicinal value, but the extraction and separation technology were limited by low composition, complex composition, and strong volatility. This study validated the feasibility of membrane separation technology for enriching volatile oil from the aspects of membrane separation efficiency, volatile oil components, and drug efficacy. A shellac coated alumina ceramic (lac@AC) membrane with irregular nanoneedle-like surface structure was prepared to enrich the volatile oil from vinegar-processed Cyperi Rhizoma (vpCR). Compared to the alumina ceramic (AC) membrane, the lac@AC membrane exhibited 29.77 % and 98.05 % increase in water and emulsion flux, respectively. Meanwhile, the oil rejection of lac@AC membrane increased 26.29 %. According to the gas chromatography-mass spectrometry analysis, the similarity between the volatile oils obtained by membrane separation and the traditional steam distillation method was higher than 99.5 %. In addition, antibacterial experiments showed that the volatile oil obtained by membrane separation has similar antibacterial effects to the volatile oil obtained by steam distillation. Component analysis and pharmacodynamic analysis both demonstrated the feasibility of using membrane separation to obtain vpCR volatile oil. This study offers a technical reference for the efficient, high-quality, and environmentally friendly extraction of natural plant oils with complex ingredients. [Display omitted] [ABSTRACT FROM AUTHOR]