Crystal growth and structural analysis of perovskite chalcogenide BaZrS3_3 and Ruddlesden-Popper phase Ba3_3Zr2_2S7_7

Perovskite chalcogenides are gaining substantial interest as an emerging class of semiconductors for optoelectronic applications. High quality samples are of vital importance to examine their inherent physical properties. We report the successful crystal growth of the model system, BaZrS$_3$ and its Ruddlesden-Popper phase Ba$_3$Zr$_2$S$_7$ by flux method. X-ray diffraction analyses showed space group of $Pnma$ with lattice constants of $a$ = 7.056(3) \AA\/, $b$ = 9.962(4) \AA\/, $c$ = 6.996(3) \AA\/ for BaZrS$_3$ and $P4_2/mnm$ with $a$ = 7.071(2) \AA\/, $b$ = 7.071(2) \AA\/, $c$ = 25.418(5) \AA\/ for Ba$_3$Zr$_2$S$_7$. Rocking curves with full-width-at-half-maximum of 0.011$^\circ$ for BaZrS$_3$ and 0.027$^\circ$ for Ba$_3$Zr$_2$S$_7$ were observed. Pole figure analysis, scanning transmission electron microscopy images and electron diffraction patterns also establish high quality of grown crystals. The octahedra tilting in the corner-sharing octahedra network are analyzed by extracting the torsion angles.Comment: 4 Figures, 2 Table

Experimental Measurement of Thermal Conductivities in a Thin Heterogeneous Structure of Thermal Diodes

Thermal diode has a wide application in the field of thermal management and thermal control. This article reports experimental results about measurement of the thermal conductivities of a novel thin layer (the thickness is about 0.3mm) for thermal diode applications. The layer consists printing paper, nylon mesh and liquid water, which are sealed between two pieces of aluminum, thus has a heterogeneity sublayers structure. It is shown that the thermal conductances are different in the two opposite through-plane directions. At 75 ˚C, the thermal conductivity is 0.457 W/mK in the conductive direction, more than 3 times larger than that in the opposite direction (0.133 W/mK). This phenomenon is due to the one-direction flow of working fluid. The thermal performance is dependent on the operating temperature and liquid water content in the structure

Cold Stress-induced Glucosyltransferase CsUGT78A15 is Involved in the Formation of Eugenol Glucoside in Camellia sinensis

Eugenol is a natural phenolic compound known for its health-promoting properties and its ability to add a floral scent to tea plants. Plant eugenol glycosides have been identified and shown to make important contributions to fruit floral quality. However, the details of their biosynthesis and metabolism in tea plants are still unknown. Here, eugenol glucoside was unambiguously identified as a native metabolite in the tea plant, and its biosynthesis was shown to be induced by low temperature treatment. Through the analysis of UGTs induced by low temperature, the glycosyltransferase CsUGT78A15 was identified in tea, and its encoded protein was shown to catalyze the glucosylation of eugenol. Vmax/Km ratios showed that eugenol was the most suitable substrate for CsUGT78A15. Sugar donor preference analysis showed that CsUGT78A15 had a higher selectivity for glucose, followed by galactose and glucuronic acid. The expression of CsUGT78A15 was correlated with the accumulation of eugenol glucoside in different tissues and genotypes of tea. Down-regulation of CsUGT78A15 led to a decreased eugenol glucoside content under cold stress, indicating that CsUGT78A15 plays an important role in the biosynthesis of eugenol glucoside under cold stress. The identification of eugenol glucoside in the tea plant and the discovery of a cold stress-induced eugenol glucosyltransferase in tea provide the foundation for the improvement of tea flavor under cold stress and the biotechnological production of eugenol glucoside