A single-phased silicate compound （Ba1-xCex）9（Sc1-yMny）2Si6O24 was prepared by solid-state reaction at high temperature. From powder X-ray diffraction （XRD） analysis, the formation of Ba9Sc2Si6O24 with an R3 spa...A single-phased silicate compound （Ba1-xCex）9（Sc1-yMny）2Si6O24 was prepared by solid-state reaction at high temperature. From powder X-ray diffraction （XRD） analysis, the formation of Ba9Sc2Si6O24 with an R3 space group was confirmed. In the photoluminescence spectra under ultraviolet （UV） ray excitation, the Ba9Sc2Si6O24：Ce3＋,Mn2＋ phosphor emits two distinctive color light bands： a blue one originating from Ce3＋and a red one caused by Mn2＋. The energy transfer process from Ce3＋ to Mn2＋ was confirmed, the critical radius as well as the transfer efficiency was calculated, and the energy transfer mechanism was discussed. In addition, the decay-time testing indicates that the energy transfer efficiencies from Ce（1） to Mn2＋ and Ce（2） to Mn2＋ are different. The emission chromaticity of Ba9Sc2Si6O24：Ce3＋,Mn2＋ phosphor could be tuned from blue to red by altering the Ce3＋/Mn2＋ concentration ratio.展开更多
The crystal of the title compound Sr6Gd0.61Sc1.39(BO3)6 (Mr = 1037.00) was grown by Czochralski method. It crystallizes in trigonal, space group 3Rwith a = 12.415(2), c = 9.274(2) ? Z = 3, V = 1238.0(4) 3, Dc = 4.173 ...The crystal of the title compound Sr6Gd0.61Sc1.39(BO3)6 (Mr = 1037.00) was grown by Czochralski method. It crystallizes in trigonal, space group 3Rwith a = 12.415(2), c = 9.274(2) ? Z = 3, V = 1238.0(4) 3, Dc = 4.173 g/cm3, l(MoKa) = 0.71073 ? m = 22.278 mm-1, F(000) = 1411, S = 1.213, the final R = 0.0577 and wR = 0.1414 for 401 observed reflections with I>2s(I). In the structure Gd(1)O6 (Gd(1) = Gd0.46 + Sc0.54) and Gd(2)O6 (Gd(2)= Gd0.15 + Sc0.85) are alternately stacked between the planar triangular BO3 groups to form chains extending along the trigonal axis. These chains are connected through the 9-coordinate Sr atoms.展开更多
Dear Editor： Omega-3 polyunsaturated fatty acids （n-3 PUFAs） are essential fatty acids for normal cellular functions and have been used for prevention and treatment of many diseases, including coronary heart disea...Dear Editor： Omega-3 polyunsaturated fatty acids （n-3 PUFAs） are essential fatty acids for normal cellular functions and have been used for prevention and treatment of many diseases, including coronary heart disease, dia- betes, and cancers. n-3 PUFAs and n-6 PUFAs have been shown to decrease and increase the severity of several human diseases, respectively. Unfortunately,展开更多
基金the National Natural Science Foundation of China(Grant No.51272027)the Specialized Research Fund for the Doctoral Program of Higher Education of China(Grant No.20100006110011)
文摘A single-phased silicate compound （Ba1-xCex）9（Sc1-yMny）2Si6O24 was prepared by solid-state reaction at high temperature. From powder X-ray diffraction （XRD） analysis, the formation of Ba9Sc2Si6O24 with an R3 space group was confirmed. In the photoluminescence spectra under ultraviolet （UV） ray excitation, the Ba9Sc2Si6O24：Ce3＋,Mn2＋ phosphor emits two distinctive color light bands： a blue one originating from Ce3＋and a red one caused by Mn2＋. The energy transfer process from Ce3＋ to Mn2＋ was confirmed, the critical radius as well as the transfer efficiency was calculated, and the energy transfer mechanism was discussed. In addition, the decay-time testing indicates that the energy transfer efficiencies from Ce（1） to Mn2＋ and Ce（2） to Mn2＋ are different. The emission chromaticity of Ba9Sc2Si6O24：Ce3＋,Mn2＋ phosphor could be tuned from blue to red by altering the Ce3＋/Mn2＋ concentration ratio.
基金Supported by the National Natural Science Foundation of China (50272066) and the Key Project of Science and Technology of Fujian Province (2001H107)
文摘The crystal of the title compound Sr6Gd0.61Sc1.39(BO3)6 (Mr = 1037.00) was grown by Czochralski method. It crystallizes in trigonal, space group 3Rwith a = 12.415(2), c = 9.274(2) ? Z = 3, V = 1238.0(4) 3, Dc = 4.173 g/cm3, l(MoKa) = 0.71073 ? m = 22.278 mm-1, F(000) = 1411, S = 1.213, the final R = 0.0577 and wR = 0.1414 for 401 observed reflections with I>2s(I). In the structure Gd(1)O6 (Gd(1) = Gd0.46 + Sc0.54) and Gd(2)O6 (Gd(2)= Gd0.15 + Sc0.85) are alternately stacked between the planar triangular BO3 groups to form chains extending along the trigonal axis. These chains are connected through the 9-coordinate Sr atoms.
文摘Dear Editor： Omega-3 polyunsaturated fatty acids （n-3 PUFAs） are essential fatty acids for normal cellular functions and have been used for prevention and treatment of many diseases, including coronary heart disease, dia- betes, and cancers. n-3 PUFAs and n-6 PUFAs have been shown to decrease and increase the severity of several human diseases, respectively. Unfortunately,
