WO3对掺铒碲酸盐玻璃的光谱性质的影响

为了满足光通信技术发展对光放大器材料的带宽要求,采用固相法制备了掺铒碲钨酸盐玻璃,研究了其光谱性质和热稳定性。用Judd-Ofelt理论计算了光谱的强度参量,根据McCumber理论计算了受激发射截面,其最大受激发射截面为1.85×10-20cm2,荧光半峰全宽最大值为104nm;用差热法分析了玻璃的热稳定性,析晶温度和转变温度之差最大值为131℃。结果表明,掺铒碲钨酸盐玻璃是一种良好的宽带放大器材料。     

新型掺铒碲酸盐玻璃光谱性质和热稳定性研究

采用高温熔融法制备了掺Er3 :TeO2-B2O3-SiO2-Na2O系列玻璃样品.对样品吸收光谱、发射光谱、差热曲线和Er3 :4I13/2能级的荧光寿命进行了测试和分析.计算得到Er3 的J-O强度参数Ωλ(λ=2,4,6),讨论了SiO2的含量对Er3 在该系列玻璃样品中发光性能的影响.结果表明,SiO2的引入有效提高了玻璃材料的有效发射带宽和热稳定性,有效抑制了材料的荧光上转换效应.同时,计算得到Er3 :4I13/2→4I15/2能级的量子效率为ηmax＝63%.     

Luminescent properties of Eu~（3＋） doped Gd_2WO_6 and Gd_2（WO_4）_3 nanophosphors prepared via co-precipitation method

Eu3+ doped Gd2WO6 and Gd2(WO4)3 nanophosphors with different concentrations were prepared via a co-precipitation method. The structure and morphology of the nanocrystal samples were characterized by using X-ray diffraction (XRD) and field emission scanning electron microscopy (FE-SEM), respectively. The emission spectra and excitation spectra of samples were measured. J-O parameters and quantum efficiencies of Eu3+ 5D0 energy level were calculated, and the concentration quenching of Eu3+ luminescence in different matrixes were studied. The results indicated that effective Eu3+:5D0-7F2 red luminescence could be achieved while excited by 395 nm near-UV light and 465 nm blue light in Gd2WO6 host, which was similar to the familiar Gd2(WO4)3:Eu. Therefore, the Gd2WO6:Eu red phosphors might have a potential application for white LED.     

Mechanism of upconversion emission enhancement in Y_3Al_5O_（12）：Er~（3＋）/Li~＋ powders

Er3+ and Li+ codoped Y3Al5O12(YAG) powders were prepared for a systematic investigation of their upconversion emissions.X-ray diffraction(XRD),upconversion emission spectra,pump power dependence,FT-IR spectra and decay time were studied to characterize the samples.With Li+ doping,the upconversion emission intensity of Er3+ doped YAG powders was obviously enhanced,accompanied with an increase in the ratio of green to red intensity.The enhancement of emission intensity could be attributed to two mechanisms:on...     

Sn掺杂对ZnO压敏变阻器电学性能的影响

本文采用沉淀法以SnCl2·H2O代替SbCl3制备了ZnO压敏变阻器.分析了SnO2含量对变阻器电学性能的影响.随着SnO2含量的增加,漏电流和压敏电压明显增大;而非线性系数在SnO2掺杂量达到3.0 mol％时达到极大值.通过适当的掺杂,得到了漏电流为0.08 μA,非线性系数为80.3,压敏电压为1006.7 V1mA/mm性能良好的ZnO变阻器.     

新型掺铒碲酸盐玻璃光谱性质和热稳定性研究

采用高温熔融法制备了掺Er^3＋：TeO2-B2O3-SiO2-Na2O系列玻璃样品。对样品吸收光谱、发射光谱、差热曲线和Er^3＋：4I 13／2能级的荧光寿命进行了测试和分析。计算得到Er^3＋的J-O强度参数Ωλ（λ=2,4,6）,讨论了SiO2的含量对Er^3＋在该系列玻璃样品中发光性能的影响。结果表明,SiO2的引入有效提高了玻璃材料的有效发射带宽和热稳定性,有效抑制了材料的荧光上转换效应。同时,计算得到Er^3＋：^4 I13／2→^4I 15/2能级的量子效率为ηmax=63％。     

不同活体饵料对中国林蛙幼蛙生长发育的影响

研究饲喂不同活体饵料——蚯蚓、黄粉虫幼虫和蝇蛆对来源相同、个体大小无明显差异、刚度过变态期的中国林蛙幼蛙生长发育的影响.结果表明:饲喂蚯蚓的组其中国林蛙幼蛙的增长率、增重率与饲喂黄粉虫幼虫、蝇蛆的组相比差异显著,增长率达28.18％,增重率达34.44％,存活率达99％.蚯蚓作为开口饵料效果较佳.     

Eu3+∶Y2O3纳米晶的微波法制备和发光性能研究

采用微波法合成了Eu3+∶Y2O3纳米晶,通过控制制备条件得到了不同形貌的Eu3+∶Y2O3纳米晶.Eu3+∶Y2O3纳米晶的形貌随微波反应时间变化明显,当反应时间延长时,Eu3+∶Y2O3纳米晶由纳米球过度为纳米棒,表面态减少.随着表面态减少S6格位与C2格位比值增加,且电荷迁移带发生红移.同时,Eu3+∶Y2O3纳米晶的发光增强.结果表明Eu3+∶Y2O3纳米晶的发光行为与表面态关系密切.     

均匀沉淀法制备纳米氧化锌的工艺条件

以尿素为沉淀剂，采用均匀沉淀法可溶性Zn^2 盐反应制备纳米ZnO。从可溶性Zn^2 盐中优化出最佳原料为硝酸锌。通过正交试验法筛选出最佳工艺条件是：尿素与硝酸锌的物质的量比3.5:1，反应时间为1.0h，反应温度为105℃；收率为93.80%，粒径为11－17nm。     

纳米晶CaWO_4∶Eu~(3+)的制备和发光性质的研究

使用共沉淀法成功制备出了纳米晶CaWO4∶Eu3+发光粉体。样品的XRD衍射图样显示了样品为单相的体心四方晶系CaWO4。对比不同掺杂浓度和不同煅烧温度样品发射谱,发现不同条件下的样品激发峰强度不同,Eu3+在配位场中占据在低对称的格位。对样品强发射峰进行监测,可观测到样品中的基质和Eu3+离子之间存在能量传递。在相同的激发条件下,发现荧光强度随着掺杂浓度变化,将Eu3+掺杂到CaWO4基质中会发生浓度猝灭,掺杂Eu3+的最佳浓度为5mol%。