110 research outputs found
Application of Dehydroabietic Acid in Palladium-Catalysed Enyne Cycloisomerisation
No full textDehydroabietic acid (DAA) promotes palladium(0)-catalysed cyclisations of arene-tethered 1,7-enynols and 1, m-enynoates (m = 6,7) to give fused carbocyclic dienes. 6,6,6,5-Tetracyclic lactones are accessible by one-pot cycloisomerisation/DielsAlder reaction/lactonisation from 1,7-enynols. Furthermore, asymmetric counteranion-directed cataly-sis has been developed, which afforded an indene derivative with an all-carbon quaternary stereogenic center.SCI(E)ARTICLE142442-244735
The preparation and infrared radar stealth performance test of a new paraffin-based phase transition microcapsule
No full textA large-scale group decision-making method for site selection of waste to energy project under interval type-2 fuzzy environment
No full textOrthogonal Frequency Division Multiplexing with Phase Modulation and Constant Envelope Design
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Evaluation of Growth, Thermal, and Spectroscopic Properties of Er3+-Doped CLNGG Crystals for Use in 2.7 μm Laser
No full textA series of optical-quality Er3+-doped calcium lithium niobium gallium garnet (CLNGG) single crystals with different Er3+ ion concentration (10, 15 and 30 at.%) has been grown by the Czochralski method. A comparative study of their structure, thermal, and spectroscopic properties is performed. Crystal structure was analyzed with X-ray powder diffraction (XRPD) and refined by the Rietveld method, results showing that the Er:CLNGG crystal possesses a cubic structure with space group Ia3¯d, and the lattice constants decrease linearly as the Er3+ concentration increase. The complete set of thermal properties were systematically studied for the first time. It has been found that all the thermal conductivities increase with temperature, indicating a glass-like behavior. Effect of Er3+ concentration on spectroscopic properties of Er:CLNGG crystals was studied. Results show that with the Er3+ concentration increase, the NIR fluorescence around 1600 nm weakens, while the Mid-IR fluorescence intensity around 2700 nm strengthens. Fluorescence lifetime of 4I13/2 decreased faster than that of 4I11/2 with the Er3+ concentration increase, which is beneficial for surmounting the “bottleneck” effect to achieve 2.7 μm laser. All the results show that CLNGG crystal with high Er3+ concentration is a potential candidate for the 2.7 μm laser
A Novel Comprehensive Quality Index QoX and the Corresponding Context-aware System Framework
No full textChemInform Abstract: The Indium‐Catalyzed Hydration of Alkynes Using Substoichiometric Amounts of PTSA as Additive.
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