Effects of Host Doping on Spectral and Long-Lasting Properties of Sm^3＋ -Doped Y2O2S

Gd- or Lu-doped long afterglow red phosphor Y2O2S：Sm^3＋ was synthesized using the high temperature flux fusion method. The obtained phosphors were analyzed using X-ray diffraction to determine the crystal structure, and the phase analyses show that the product is in single phase. The luminescence spectra and decay curve were measured on a Hitachi F-4500 fluorescence spectrophotometer. The decay time was determined on an ST-900PM weak light photometer. The analyses show that host doping of Lu improves both luminescence and decay time of the materials. The concentration of doped Lu and Sm was varied in order to determine the optimal condition and to synthesize the product with the best properties. The mechanism of the long afterglow was also briefly discussed.     

Sr8Si4O12Cl8:Eu3+,M3+(M3+=Bi3+,Gd3+)中Eu3+的敏化发光

以Na2CO3为电荷补偿剂,采用高温固相法合成了碱土氯硅酸盐Sr8Si4O12Cl8:(Eu3 M3 )(M=Bi3 ,Gd3 )荧光材料.X射线衍射分析结果表明:合成的Sr8Si4O12Cl8:(Eu3 ,M3 )为纯四方相.Eu3 的发射主峰位于614 nm,为5D0→7F2的电偶极跃迁,表明Eu3 处于非中心对称格位,即取代Sr2 的位置.通过对其激发光谱和发射光谱研究,发现敏化剂Bi3 ,Gd3 的掺入对Eu3 的发射具有较强的敏化作用,当Bi3 和Gd3 的掺杂量(摩尔分数)分别为5.0%时,Eu3 的相对发光强度分别提高了29.4%和23.6%.     

封端不饱和聚酯树脂的合成及性能研究

在合成通用型不饱和聚酯(UP)树脂的基础上,反应后期分别用环己醇、苯甲酸及环己醇/苯甲酸进行封端处理,得到封端改性UP树脂.对封端前后UP树脂的性能进行了研究,发现封端后UP树脂的性能与通用型UP树脂的性能基本相当,但耐腐蚀性明显提高,其中酸值50 mg KOH/g时封端的UP树脂的耐腐蚀性比酸值80 mgKOH/g时封端强,而采用环己醇/苯甲酸同时封端后耐腐蚀性提高得更为明显.     

基质掺杂对CdSiO_3∶Sm~(3+)体系红色长余辉发光材料的影响

采用传统的高温固相反应合成了基质掺杂的Cd(RE1Si)O3∶Sm3 (RE=Al,Ga,v,Mo,zr,Ti,W)长余辉发光材料.用荧光光谱仪研究了对CdsiO3∶Sm3 体系进行不同离子的掺杂所得样品的光谱性质.对离子掺杂影响产物性能的研究表明,掺杂离子电荷是主要的影响因素,具有较高电荷的Mo、W的掺杂对产物的余辉时间具有明显的增强作用,其余辉时间分别达到453s和924s.     

钒酸铋/二氧化钛-石墨烯宽光谱复合光催化剂的制备及性能

通过溶剂热法制备了具有可见光光催化活性的BiVO₄/TiO₂-石墨烯复合光催化剂.利用X射线粉末衍射、透射电子显微镜、紫外-可见漫反射光谱和荧光发射光谱对样品进行表征,复合光催化剂的催化活性以模拟太阳光条件下降解水溶液中亚甲基蓝来评价.结果表明:BiVO₄/TiO₂-石墨烯复合光催化剂在530-800 nm的可见光范围具有很强的吸收峰.石墨烯的引入不仅拓宽了光谱响应范围,而且使得BiVO₄和TiO₂粒子均匀地分散在石墨烯薄片上,能快速捕获并迁移电子,有效地提高了光生载流子的分离效率,从而提高其光催化活性.      

Photoluminescence of Cerium(Ⅲ)in Lanthanum Strontium Halophosphates

La_(1.5)Sr_(7.0)Na_(1.5)(PO_4)_6X′X″(X′and X″stand for two identical or different halide ions F~-,Cl~-,and Br~-)is anew kind matrix of phosphors.X-ray analysis shows that these crystals belong to the apatite structure ofhexagonal system with a space group of p6_(3/m).Their lattice parameters have been obtained.Subsolidus phaserelationship in the double halophosphate systems were determined by lattice parameter method.It has beenproved that in the Br-Cl and F-Cl systems there exist complete and continuous solid solutions.In the F-Br sys-tem there appears a two phase region with the bromide composition 0.75     

工科无机化学的理想教材--介绍大连理工大学编写的《无机化学》

本文从我校工科无机化学教学要求、教材选择和使用情况谈起,陈述了我们对大连理工大学编写的第四版<无机化学>教材的体会和认识.