【摘 要】
:
A novel synthesis process, based on the polyacrylamide gel method, was used to prepare Ce-doped YAG phosphor powders. Effects of heat treatment parameters, temp
【机 构】
:
Department of Materials Science and Engineering
论文部分内容阅读
A novel synthesis process, based on the polyacrylamide gel method, was used to prepare Ce-doped YAG phosphor powders. Effects of heat treatment parameters, temperature and holding time, the fluxes, and atmosphere on microstructure and particle morphology as well as luminescent properties of YAG:Ce3+ phosphor powders were studied by X-ray powder diffractometry,scanning electron microscopy, and fluorescence spectrophotometry. The results show that the formation temperature (1 000 ℃) of pure YAG phase is significant low when being synthesized by the polyacrylamide gel method, compared with solid-state reaction.For luminescent properties, the intensity of emission of YAG:Ce3+ phosphor increases steadily with increasing temperature from 900℃ to 1 300 ℃ and prolonging holding time from 100 min to 400 min. But blue shift phenomenon is observed for 400 min calcination.Fluxes as BaF2 and H3BO3 can enhance the intensity of emission of phosphor due to the improvement of crystallization of YAG and the stabilization of trivalence cerium ion in YAG host lattice at high temperature. Weak reduction atmosphere can contribute to improvement of the emission intensity of YAG:Ce3+ phosphor powders.
其他文献
This paper presents a 2D analytical solution for the transverse velocity distribution in compound open channels based on the Shiono and Knight method (SKM), in
以宁夏银北灌区为实例,把土壤临界含盐量、地下水临界埋深和临界矿化度概念引入水资源管理中,建立了防治盐碱化的多目标决策模型,并利用约束法和模拟方法对不同水平年银北灌区的引、采、排水量进行优化计算。该模型实现了水资源优化配置对三大水盐指标,即地下水埋深、土壤含盐量和地下水矿化度的全面调控,可用于干旱、半干旱地区以防治土壤盐碱化为目的的灌排管理决策。
In order to study the engineering behaviors of reinforced gabion retaining wall, laboratory model test was carried out. Cyclic load and unload of five levels (0
A 1/3-scale reinfored concrete (RC) frame of unequal storey height with specially shaped columns was tested under low frequency cyclic loading. The damage chara
The existence of the pullback attractor for the 2D non-autonomous g-Navier-Stokes equations on some bounded domains is investigated under the general assumption
According to the existing problems of liquefaction models of saturated sand that were put forward under dynamic action, on the basis of Handin-Drnevich model, a
Thin films of PrCoO3 were deposited on LaAlO3 substrates by pulsed laser deposition technique. X-ray diffraction result indicates that films are single phase an
In order to analyze the seismic response characteristics of pile-supported structure, a computational model considering pile-soil-structure interaction effect w
The micromigration of oil-drive-water and gas-drive-water in oil and gas fields was studied, by using core slices and micro-experimental technology, and the mig
In this paper, a back propagation artificial neural network (BP-ANN) model is presented for the simultaneous estimation of vapour liquid equilibria (VLE) of fou