不同制备工艺过程对Al18B4O33:Eu3+荧光特性的影响

以 9Al2 O3·2B2 O3和含 1 5mol%过量H3BO3为配方 ,用固相反应法在Al2 O3～B2 O3体系中合成基质Al1 8B4O33,并用固相反应法合成了两种荧光粉 ,对所得两种荧光粉的荧光光谱进行测试 ,结果表明两种荧光粉发射红色荧光 ,但它们的发射荧光光谱彼此不同 ,对荧光谱的分析和比较表明 ,制备工艺过程对荧光粉的荧光特性有明显的影响 .     

BaFBr∶Eu发光材料的~（151）Eu穆斯堡尔谱及X射线光电子能谱研究

首次报道了ＢａＦＢｒ：Ｅｕ发光材料的（１５１）Ｅｕ穆斯堡尔谱。结果表明ｆ（Ｅｕ２＋）＜ｆ（Ｅｕ（３＋）），即＜Ｘ２＞Ｅｕ（２＋）＞＜ｘ２＞Ｅｕ（３＋），说明声子与Ｅｕ（２＋）的作用比声子对Ｅｕ（３＋）的作用大。实验结果也证明当温度降低时，ｆ（Ｅｕ（２＋））的增长比ｆ（Ｅｕ（３＋））的增长快，并且发现当温度降低时，Ｅｕ（２＋）的相对含量减少，而Ｅｕ（３＋）的含量增加．变温实验提供的证据表明Ｅｕ（２＋）与Ｅｕ（３＋）之间有电子的“跳动”。穆斯堡尔谱的实验结果还与ＸＰＳ及发光的结果进行了对比和讨论。     

Direct pyrolysis mass spectrometry analysis of fresh and aged $\hbox{PF}_{6}^{-}$‐doped polythiophenes

In this study, pyrolysis mass spectrometry has been applied for the investigation of thermal characteristics of ‐doped polythiophene (PTh) films. Thermal degradation of PTh showed behaviour identical with ‐doped polythiophene (BF₄‐PTh), indicating that the effects of the dopants in question on the thermal characteristics of the PTh are not significant. Besides the oligomer peaks (up to hexamer), peaks indicating decomposition of the thiophene ring have also been detected as in the case of BF₄‐PTh. However, the data also indicated that the oxidation of the dopant was much more effective, yielding mainly POF₃, H₃PO₄ compounds even for the freshly prepared samples. Upon ageing, the yield of these products increased and exposure to air for more than 50 days also caused degradation of the PTh chains. Furthermore, substitution of the thiophene (Th) ring by fluorine has been recorded and was associated with reactions of Th with the reactive oxidation products of the dopant. Analyses of the de‐doped samples showed that although de‐doping was effective to a certain extent, inward diffusion of the counter ion (C₄H₉)₄N⁺ has also occurred. This diffusion was more efficient than that was observed for BF₄‐PTh samples. Copyright © 2004 Society of Chemical Industry     

掺铕稀土配合物的光学树脂荧光光谱研究

报道了将多种稀土铕配合物复合于苯乙烯(ST)／甲基丙烯酸(HMA)的共聚体系,研究了含稀土配合物透明光学树脂的光学性能。发现其具有发光效率高,光谱呈现尖锐的线状谱带及相对于纯稀土配合物粉末来说掺有稀土配合物的光学树脂的发射产生光谱红移等特点。特别是用电子云重排效应(当中心稀土离子与不同配体结合时,其相同的J能级间的跃迁谱带位置略有移动的现象)解释了掺有稀土配合物的光学树脂发射光谱红移现象。并推断出在含稀土配合物复合于光学树脂后。稀土中心离子和配位原子间距离有所减小。     

125I粒子源活度的测量

为了控制粒子源植入组织间实施近距离放射治疗的质量,防范医疗照射事故的发生,按照国际原子能机构1274号技术报告要求,对同一批次(50枚)放射源的10%(5枚)进行检测,并要求测得的粒子源的表观活度与厂家给出值的相对偏差在5%以内.本文介绍了我院临床上使用的125I粒子源(6711型)的活度的测定方法.采用井型电离室测定125I粒子源的空气比释动能率,进而估算出125I粒子源的表观活度(又称等效活度),并对结果进行了分析.结果表明,该批125I粒子源的活度合格率达到80%.     

192Ir源辐射事故中受照人员的临床观察

对在华南地区某次192Ir源人为辐射事故中受照的50例患者进行了临床观察.结果发现,受照的全部患者均出现不同程度的临床症状,其中8例发生染色体畸变,临床诊断为1例亚急性轻(中)度放射病,1例先兆流产.结果表明人为辐射事故危害性极大,受照人员临床表现多样,需要及时诊断和治疗,同时需要长期随访观察.     

聚变堆氦冷固态包层结构和6Li富集度对产氚率的影响

在聚变堆固态包层基本参数基础上，建立简化20°模型，包层分第1壁装甲、第1壁冷却板、氚增殖区和支撑结构。分别选择Li₄SiO₄和Li₂O做增殖材料，应用MCNP程序，研究第1壁结构布置和6Li富集度对产氚率的影响。结果表明：₆Li富集度适宜选择在30％~80％之间；第1壁选择Be装甲可提高产氚率；冷却管板的厚度应取3cm以下，以避免对产氚造成不利的影响。     

Improved optical photoluminescence by charge compensation in the phosphor system CaMoO4:Eu

It has been found that charge compensated CaMoO₄:Eu³⁺ phosphors show greatly enhanced red emission under 393 and 467 nm-excitation, compared with CaMoO₄:Eu³⁺ without charge compensation. Two approaches to charge compensation, (a) 2Ca²⁺ → Eu³⁺ + M⁺, where M⁺ is a monovalent cation like Li⁺, Na⁺ and K⁺ acting as a charge compensator; (b) 3Ca²⁺ → 2Eu³⁺ + vacancy, are investigated. The influence of sintering temperature and Eu³⁺ concentration on the luminescent property of phosphor samples is also discussed.     

Preparation of Non-Grinding Long Afterglow SrAl2O4 ：Eu^2＋ , Dy^3＋ Material by Microwave Combustion Method

The non-grinding long afterglow material SrAl2O4：Eu^2＋ , Dy^3＋ was prepared by combustion method in home mierowave oven direetly, after dispersant, frother, eomburent, and mineralizer were added into the reacting system. XRD analysis showed that the powders were nearly pure SrAl2O4 phase with few other phases, and the size of the grain was 41.1 nm. Fluoreseenee speetrum results indieated that there were 2 exeitation peaks loeated at 345 and 400 nm, and the emission peak loeated at 516 nm, afterglow lasted up to 30 min or more. The mierowave eombustion method has advantages of less time, low temperature and no grinding process, and the material made by the method has good luminescent property.     

BaMgAl10O17:Eu2+稳定性的机理及提高方法

主要概述了蓝色荧光粉(BaMgAl10O17 : Eu2 ,BAM)的研究现状,分析了BAM荧光粉的晶体结构和发光机理,着重介绍了BAM荧光粉在高温灼烧或紫外辐射下的热劣化机理模型,以此对改善BAM热劣化性能的各种方法进行评述,最后展望了BAM的研究.