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Properties of Local Structure Surrounding Eu3+ Ion in Various Niobate-Silicate Glasses 总被引:3,自引:0,他引:3
A Series of niobate-silicate glasses doped with Eu3 ions were prepared. The emission, phonon-side band spectra, fluorescence line narrowing spectroscopy and fluorescence lifetimes in these glasses were studied. The intensity parameters and crystal field parameter of Eu3 were obtained. The results indicate that the intensity ratio of the electric-dipole to magnetic-dipole transition and the intensity parameter Ω2 increase with the increasing concentration of Nb2Os, indicating that the symmetry becomes lower, the Eu-O bonds become stronger and the covalency of Eu-O bond increases. The value of B20 decreases with the increasing concentration of Nb2O5, indicating that the distance between the Eu3 ion and oxygen decreases and the Eu-O bond becomes strong, corresponding to the results of the former. As the concentration of Nb2O5 increases, the electron-phonon coupling becomes stronger, thus the nonradiative transition rate of 5Do becomes larger and the lifetime of 5D0 becomes shorter. 相似文献
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通过数值模拟的方法计算了圆坯感应加热过程的温度分布情况,研究了线圈匝数、聚磁体、坯料表面与空气的对流换热等因素对感应加热的影响。结果表明,线圈匝数对坯料温度分布有较大的影响,为了得到相对均匀的温度分布需选择合理的线圈匝数;感应加热中采用聚磁体,可显著提高坯料端部温度,消除坯料端部温度偏低的现象;同时,计算了感应加热过程的磁场分布,解释了坯料温度分布和变化的原因,并提出控制感应加热过程坯料温度的合理措施。 相似文献
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用Ar~ 离子激光器的4880线和He-Ne激光器的6328线同时激发ZnS:Mn~(2 ),Sm~(3 )粉末材料时,我们发现Sm~(3 )中心的发光强度比只用4880线激发明显增长。增长的程度随6328线功率的增加而变强。若用短于4880的激光线(如4658,4727)与6328线同时激发ZnS:Mn~(2 ),Sm~(3 ),Sm~(3 )中心发光强度I_(Sm)明显增长,Mn~(2 )中心发光强度I_(Mn)则稍有下降,当增大 相似文献
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