2010年10月21日,美国阔叶木地板联合会(Coalition For American Hardwood Parity)代表美国多层实木地板产业(Multilayered)向美国商务部和国际贸易委员会提交申请,要求对原产于中国的多层实木地板进行反倾销、反补贴立案(双反案)...2010年10月21日,美国阔叶木地板联合会(Coalition For American Hardwood Parity)代表美国多层实木地板产业(Multilayered)向美国商务部和国际贸易委员会提交申请,要求对原产于中国的多层实木地板进行反倾销、反补贴立案(双反案)调查,展开更多
Red phosphors MgxCa1-xTiO3:Eu3+ (0〈x〈0.5) were synthesized by solid-state reaction method. The crystalline structure and morphology of the as-prepared samples were confirmed by X-ray diffraction (XRD) and scan...Red phosphors MgxCa1-xTiO3:Eu3+ (0〈x〈0.5) were synthesized by solid-state reaction method. The crystalline structure and morphology of the as-prepared samples were confirmed by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The luminescence property was measured using photoluminescence excitation and photoluminescence emission spectra. Results showed that spherical particles appeared in the phosphor bodies and size of the phosphor particles were tmiformly distributed in the range of 600-800 nm when the Mg2+ concentration was about 40 mol.%. It could readily be seen that the strongest PL emission was located at 617 nm monitored at 398 nm, which well matched with the near ultraviolet (NUV, 395400 nm) GaN-LEDs. More importantly, PL emission intensity (617 nm) of phosphor Mg0.nCa0.6TiO3:0.03Eu3+ was 4.26 times of that of phosphor CaTiO3:0.03Eu3+ Based on these results, it implied that the PL intensity of phosphorCaTiO3:0.03Eu3+ could be significantly enhanced by introducing Mg2+ into CaTiO3 host lattices and the phosphor Mg0.4Ca0.6TiO3:0.03Eu3+ might be the promising red-emitting phosphor in making tricolor phosphor converted white-LEDs.展开更多
This work was aimed at improving the water-resistance stability of CaS:Eu2+,Sm2+ phosphor. An organic-inorganic com- posite coating method was adopted in order to obtain ideal phosphor. The phosphor was coated with...This work was aimed at improving the water-resistance stability of CaS:Eu2+,Sm2+ phosphor. An organic-inorganic com- posite coating method was adopted in order to obtain ideal phosphor. The phosphor was coated with SiO2 via sol-gel technique and it was also covered by polymethyl methacrylate (PMMA) via dissolution-cohesion technique. Powder X-ray diffraction (XRD) patterns, fluorescence spectroscopy and transmission electron microscopy (TEM) were employed to characterize the phase structures, emission spectrum and surface morphologies, respectively. In addition, the water-resistance stability of the phosphor was tested by soaking the phosphor into deionized water. The results showed that the phase structures remained the same as the uncoated phosphor and the po- sition of the fluorescence peak did not shift after surface treatment. Results showed that the water-resistance stability of the phosphor was improved to some degree. Moreover, the photoluminescence (PL) intensity of the coated phosphors reduced less than 10% of the original phosphors. Though being soaked into deionized water for 50 h, the phosphor coated with 10 wt.%SiO2-10 wt.%PMMA retained 85.9% PL intensity compared to that of the uncoated phosphor. Therefore, it could be concluded that the 10 wt.%SiO2-10 wt.%PMMA composite coating effectively improved the phosphor water resistance and retained its good optical properties.展开更多
基金Project supported by National Natural Science Foundation of China(11305260)
文摘Red phosphors MgxCa1-xTiO3:Eu3+ (0〈x〈0.5) were synthesized by solid-state reaction method. The crystalline structure and morphology of the as-prepared samples were confirmed by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The luminescence property was measured using photoluminescence excitation and photoluminescence emission spectra. Results showed that spherical particles appeared in the phosphor bodies and size of the phosphor particles were tmiformly distributed in the range of 600-800 nm when the Mg2+ concentration was about 40 mol.%. It could readily be seen that the strongest PL emission was located at 617 nm monitored at 398 nm, which well matched with the near ultraviolet (NUV, 395400 nm) GaN-LEDs. More importantly, PL emission intensity (617 nm) of phosphor Mg0.nCa0.6TiO3:0.03Eu3+ was 4.26 times of that of phosphor CaTiO3:0.03Eu3+ Based on these results, it implied that the PL intensity of phosphorCaTiO3:0.03Eu3+ could be significantly enhanced by introducing Mg2+ into CaTiO3 host lattices and the phosphor Mg0.4Ca0.6TiO3:0.03Eu3+ might be the promising red-emitting phosphor in making tricolor phosphor converted white-LEDs.
基金supported by National Natural Science Foundation of China(11305260)
文摘This work was aimed at improving the water-resistance stability of CaS:Eu2+,Sm2+ phosphor. An organic-inorganic com- posite coating method was adopted in order to obtain ideal phosphor. The phosphor was coated with SiO2 via sol-gel technique and it was also covered by polymethyl methacrylate (PMMA) via dissolution-cohesion technique. Powder X-ray diffraction (XRD) patterns, fluorescence spectroscopy and transmission electron microscopy (TEM) were employed to characterize the phase structures, emission spectrum and surface morphologies, respectively. In addition, the water-resistance stability of the phosphor was tested by soaking the phosphor into deionized water. The results showed that the phase structures remained the same as the uncoated phosphor and the po- sition of the fluorescence peak did not shift after surface treatment. Results showed that the water-resistance stability of the phosphor was improved to some degree. Moreover, the photoluminescence (PL) intensity of the coated phosphors reduced less than 10% of the original phosphors. Though being soaked into deionized water for 50 h, the phosphor coated with 10 wt.%SiO2-10 wt.%PMMA retained 85.9% PL intensity compared to that of the uncoated phosphor. Therefore, it could be concluded that the 10 wt.%SiO2-10 wt.%PMMA composite coating effectively improved the phosphor water resistance and retained its good optical properties.