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Micro-and nanocrystals cubic-phase SrF2:Yb3+/Er3+ upconversion luminescence phosphors were synthesized via a facile hydro-thermal route in the presence of different surfactants.The samples were characterized with X-ray diffraction (XRD),Fourier transform infra-red spectra (FT-IR),scanning electron microscopy (SEM),transmission electron microscopy (TEM),and upconversion emission spectra.As-prepared products showed a variety of morphologies,such as cubic-shaped microcrystal,hierarchical structure microspheres... 相似文献
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A series of new red-emitting BaCa1-2xBO3F:xEu3+, xM+ (M=Li, Na, K) phosphors were synthesized by the solid-reaction method. X-ray diffraction (XRD), diffuse reflection (UV-vis) and photoluminescence spectra were utilized to characterize the crystallization process, structure and luminescence properties of the as-synthesized phosphors. The XRD results indicated that the sample began to crystallize at 800 oC, and single-phase BaCaBO3F was fully obtained after annealing at 1000 oC. The charge compensated behav... 相似文献
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以双(2,4,5-三氯-6-正丁烷氧羰基苯基)草酸酯(简称CPPO)和红色荧光剂罗丹明B组成的过氧草酸酯类化学发光体系为研究对象,从粒径、用量和种类的角度讨论了分散剂云母等对体系发光效率的影响.结果表明,添加30μm云母50mg后,体系的发光寿命、强度均显著增加,发光效率较高。 相似文献
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煤的芳烃化学研究进展 总被引:2,自引:0,他引:2
当世界上的石油资源逐渐枯竭之后,煤能否成为21世纪化学工业的原材料?科学家们正面临极富感染力的挑战,即寻找和发展一条利用液化煤中的芳烃化合物合成有机化学品的新途径。近期研究表明,新兴的煤化学工业具有很大的发展潜力。本文主要讨论和介绍煤的非燃料利用问题,研究发展由煤制取芳烃化学品和材料的可能途径。综述有关文献26篇。 相似文献
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In this paper,we have investigated the spectral characteristics of Eu~(3 )ion sorbed on NaY,NaX and NaAzeolites.During calcination,the influence of Eu~(3 )ion's positions in zeolites on its spectral structures are dis-cussed emphatically.The experimental results show that the electric dipole-to-magnetic dipole transition inten-sity ratios of Eu~(3 )emission in NaY,NaX and NaA zeolites calcinated at the same temperature increase inproper order.The bonding actions between Eu~(3 )ion and framework oxygens are studied by the measurementsof excitation spectra and X-ray photoelectron spectroscopy.In the Eu~(3 )content ranging from 0.95% to10.5%,the concentration quenching of the fluorescence in Eu(Ⅲ)-NaY is not observed. 相似文献
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