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681.
Sajid Saikia Animesh Ghosh Angshuman Nag 《Angewandte Chemie (International ed. in English)》2023,62(33):e202307689
A phosphor emitting both white light and broad near-infrared (NIR) radiation can simultaneously provide visual inspection and early signs of rotting of food products. The broad NIR emission is absorbed by the vibrational overtones of water molecules present in food items, providing the non-invasive image contrast to assess the food freshness. Here we design a phosphor, namely, Cr3+-Bi3+-codoped Cs2Ag0.6Na0.4InCl6, that simultaneously emit warm white light and broad NIR (1000 nm) radiation with quantum yield 27 %. This dual emitter is designed by combining the features of s2-electron (Bi3+) and d3-electron (Cr3+) doping in a weak crystal field of the halide perovskite host. excitation of Bi3+, using a commercial 370 nm ultraviolet light-emitting-diodes (UV-LED), yields both the emissions. A fraction of the excited Bi3+ dopants emit the warm white light, and the other fraction transfers its energy non-radiatively to Cr3+. Then the Cr3+ de-excites emitting broad NIR emission. Temperature dependent (6.4–300 K) photoluminescence in combination with Tanabe-Sugano diagram show that the Cr3+ experiences a weak crystal field ( =2.2), yielding the NIR emission. As a proof of concept, we fabricated a panel containing 122 phosphor-converted LEDs, demonstrating its capability to inspect food products. 相似文献
682.
683.
Band state concept has been used for the first time to explain the Melting temperature and Debye temperature of ternary chalcopyrite semiconductors. The experimental results agree quite well with those evaluated from this model. Finally we derive a correlation between the two termperatures. 相似文献
684.
Varnakumar Gayathri K. Stephen Suresh Prem Dr. Niraikulam Ayyadurai Dr. Debasis Samanta 《European journal of organic chemistry》2023,26(14):e202201182
Click reaction or copper-assisted azide–alkyne cycloaddition (CuAAC) reaction can conveniently synthesize desired organic molecules or functionalize biological macromolecules. In many cases, trace amounts of residual copper from the reaction mixture are not trivial to remove when the exhaustive purification step is avoided to fulfill the essential criteria of a click reaction. It is often detrimental, particularly for biochemical applications or when it involves biological macromolecules. Herein, we have reported the synthesis of a new type of copper (I) complex as a smart catalyst for click reaction, which can be separated from the reaction mixture very easily by the slight elevation of temperature, thanks to its thermoresponsive behavior. The click reactions using a thermoresponsive catalyst were first studied in an aqueous medium using various organic molecules containing alkyne and azide functional groups. Later, the strategy was extended to biological macromolecules like collagen. 相似文献