Scott Kelby将为你演示如何用一个便宜的柔光伞替代昂贵的柔光箱进行拍摄照明。这期我们的目标是用一套物美价廉的装备拍出看起来像是大制作的效果。在上一期中我用了一个小的可折叠柔光伞,它很适用于拍头部肖像——但是如果你需要一个...Scott Kelby将为你演示如何用一个便宜的柔光伞替代昂贵的柔光箱进行拍摄照明。这期我们的目标是用一套物美价廉的装备拍出看起来像是大制作的效果。在上一期中我用了一个小的可折叠柔光伞,它很适用于拍头部肖像——但是如果你需要一个能够覆盖更大范围、看起来像是自然光的光源。展开更多
Photoluminescence (PL) of Bi12GeO20 and Mo doped Bi12GeO20 (Mo: Bi12GeO20) crystals in visible and near-infrared (NIR) spectral regions were studied. X-ray diffraction analysis, absorption and Raman scattering spectra...Photoluminescence (PL) of Bi12GeO20 and Mo doped Bi12GeO20 (Mo: Bi12GeO20) crystals in visible and near-infrared (NIR) spectral regions were studied. X-ray diffraction analysis, absorption and Raman scattering spectra of these crystals were also measured. Pure Bi12GeO20 after annealing in N2 atmosphere at 450 oC and 550 °C show predominant emissions at about 745 and 1250 nm bands, while the emission peaks of Mo:Bi12GeO20 crystals untreated or after annealing in Ar at 300 °C are at around 538 and 1165 nm. The results suggest that annealing induces intrinsic luminescence of Bi in pure Bi12GeO20 at room temperature and Mo influences the luminescence centers of Bi12GeO20. The emission peaks of Bi12GeO20 and Mo: Bi12GeO20 probably owe to lower-valent Bi ions.展开更多
基金supported by the National Natural Science Foundation of China (Grant Nos. 60778036, 60938001, 61078053, 51002175)the Science and Technology Commission of Shanghai Municipality (Grant No. 09JC1415300)the Hundred Talents Project of the Chinese Academy of Sciences
文摘Photoluminescence (PL) of Bi12GeO20 and Mo doped Bi12GeO20 (Mo: Bi12GeO20) crystals in visible and near-infrared (NIR) spectral regions were studied. X-ray diffraction analysis, absorption and Raman scattering spectra of these crystals were also measured. Pure Bi12GeO20 after annealing in N2 atmosphere at 450 oC and 550 °C show predominant emissions at about 745 and 1250 nm bands, while the emission peaks of Mo:Bi12GeO20 crystals untreated or after annealing in Ar at 300 °C are at around 538 and 1165 nm. The results suggest that annealing induces intrinsic luminescence of Bi in pure Bi12GeO20 at room temperature and Mo influences the luminescence centers of Bi12GeO20. The emission peaks of Bi12GeO20 and Mo: Bi12GeO20 probably owe to lower-valent Bi ions.
