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<正>YAG:Ce crystal with a diameter of 110 mm is successfully grown by the temperature gradient technique (TGT).The effects of annealing on the luminescence efficiency of YAG:Ce crystal are investigated,and the optimal annealing temperature and atmosphere are obtained.The mechanism of variation behavior of the luminescence efficiency of YAG:Ce under different annealing conditions is discussed and some details on the luminescence associated with color centers are analyzed. 相似文献
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<正>We report the luminescence properties and decay profiles of Ce:YAlO_3,Mn:YAlO_3,and Ce,Mn:YAlO_3 crystals grown by Czochralski method.The spectroscopic properties show that both Mn~(2+) ions and Mn~(4+) ions exist in Mn:YAlO_3 and Ce,Mn:YAlO_3 crystals.The Mn~(2+) ions have a broad emission band of 60 nm in Mn-doped YAlO_3 crystal at 530 nm.The luminescence spectra also indicate that there is significant energy transfer between Ce~(3+) and Mn~(4+) in Ce,Mn:YAlO_3 crystal.Because of the energy transfer,the first decay component in Ce,Mn:YAlO_3 decreases from 24.5 to 10.8 ns,which is much faster than that of Ce:YAlO_3. 相似文献
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Judd-Oflet analysis of spectrum and laser performance of Ho:YAP crystal end-pumped by 1.91μm Tm:YLF laser 下载免费PDF全文
The Ho:YAP crystal is grown by the Czochralski technique.The room temperature polarized absorption spectra of Ho:YAP crystal was measured on a c cut sample with 1 at% holmium.According to the obtained Judd-Ofelt intensity parameters Ω2 = 1.42 × 10-20 cm2,Ω4 = 2.92 × 10-20 cm2,and Ω6 = 1.71 × 10-20 cm2,this paper calculated the fluorescence lifetime to be 6 ms for 5I7 →5 I8 transition,and the integrated emission cross section to be 2.24×10-18 cm2.It investigates the room temperature Ho:YAP laser end pumped by a 1.91 μm Tm:YLF laser.The maximum output power was 4.1 W when the incident 1.91 μm pump power was 14.4 W.The slope efficiency is 40.8%,corresponding to an optical to optical conversion efficiency of 28.4%.The Ho:YAP output wavelength was centred at 2118 nm with full width at half maximum of about 0.8 nm. 相似文献
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鼻咽癌患者指甲的红外光谱研究 总被引:2,自引:0,他引:2
利用傅里叶红外光谱研究了20例正常人和3例鼻咽癌患者手指甲的红外光谱,结果表明:癌指甲样品与正常指甲样品的红外光谱在峰形、峰强度、峰频率等方面均存在明显差异;它们的最大区别是:酰氨Ⅱ带峰形的变化,δs(CH3)峰的消失,以及874.0 cm-1附近有无吸收峰。还着重研究了磷酸二酯基团的对称和反对称伸缩振动;以及C—O基团伸缩振动峰的变化。并从蛋白质、核酸氢键的角度以及膜脂碳氢链排列及构像变化角度等方面分析了发生变化的原因。磷酸二酯基团的对称伸缩振动峰呈现有规律的变化, 即癌样品由1 080.0位移到1 077.6 cm-1, 反对称伸缩振动由1 239.4位移到1 238.4 cm-1, 表明指甲核酸分子内磷酸二酯键骨架的结构发生了改变。另外, 膜脂分子中的CH2弯曲振动 δ(CH2)的波数也有些改变, 即癌样品由1 453.1位移到1 453.7 cm-1。而且,峰的强度也有所增强, 说明癌患者指甲的膜脂中亚甲基链的无序状态较正常人的大。 相似文献
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目的探讨过敏性紫癜(HSP)患儿的临床特点及发病机制。方法对76例HSP患儿急性期的临床表现进行分析总结;并采用流式细胞仪分析技术及免疫比浊法对外周血淋巴细胞亚群(CD3、CD4、CD8、CD19、NK细胞)及血清补体C3进行检测,与30例健康儿童进行对照比较。结果76例患儿中发病同时或发病前2周内有呼吸道感染62例(81.6%)。76例患儿均先后出现紫癜,以双下肢皮肤紫癜最多见,合并消化道症状56例(73.7%),其中以消化道症状为首发症状21例(27.6%);合并肾损害36例(47.3%),其以微量蛋白尿型、血尿和蛋白尿型为多见,肾病综合征型少见。HSP组急性期外周血CD4及NK细胞数量降低、CD19显著升高,与对照组比较,差异均有统计学意义(均P<0.01);血清补体C3增高,与对照组比较,差异有统计学意义(P<0.05);血CD8增高,但与对照组比较,差异无统计学意义(P>0.05)。结论 HSP患儿发病与呼吸道感染有密切关系,胃肠道症状为首发症状的比例较高,合并肾损害也较多,但以微量蛋白尿型、血尿和蛋白尿型为多见,预后良好。儿童HSP的发病与T、B淋巴细胞及NK细胞的功能紊乱有关,且补体系统也参与HSP的发病。 相似文献
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