The Y-Eu oxalate precursor was prepared with a homogeneous precipitation method. And the additives, Na2CO3, S, NaCl or their combination, were introduced into the precursor to prepare Y2O3 ：Eu^3＋ red phosphors at 10...The Y-Eu oxalate precursor was prepared with a homogeneous precipitation method. And the additives, Na2CO3, S, NaCl or their combination, were introduced into the precursor to prepare Y2O3 ：Eu^3＋ red phosphors at 1000 1300 ℃ for 2 h. The effect of molten salts on particle size and luminescent intensity was studied. The experimental results showed that the complex molten salt （Na：CO3 ＋ S ＋ NaCl） was conductive to enhance the luminescent intensity of Y2O3 ：Eu^3＋. The emission intensity of the phosphor prepared with these additives at 1300 ℃ was about 45% higher than that of the one prepared without molten salt, and about 11% higher than that of the corresponding commercial phosphor. Meanwhile, the particle size of Y2O3 ：Eu^3＋ phosphor was controlled effectively with the molten salt.展开更多
A series of thermodynamic parameters in formation of ultrafine monodispersed colloidal particles of Y(OH)CO3 were measured, estimated and calculated. The thermodynamic stability of Y(OH)CO3 colloidal particles was stu...A series of thermodynamic parameters in formation of ultrafine monodispersed colloidal particles of Y(OH)CO3 were measured, estimated and calculated. The thermodynamic stability of Y(OH)CO3 colloidal particles was studied and discussed by phenomenological model. It is suggested that ultrafine monodispersed colloidal particles of Y(OH)CO3 are stable only in a very narrow temporary supersaturation range ( 1<x<1 .08).展开更多
In the present work,the dispersion casting of Y-2O-3 particles in aluminum-copper alloy was investigated in terms of microstructural changes with respect to Cu contents of 20 （hypo）,33 （eutectic） and 40 （hyper） ...In the present work,the dispersion casting of Y-2O-3 particles in aluminum-copper alloy was investigated in terms of microstructural changes with respect to Cu contents of 20 （hypo）,33 （eutectic） and 40 （hyper） wt pct by scanning electron microscopy （SEM） and energy dispersive spectroscopy （EDS）.For the fabrication of Al-Cu alloy dispersed Y-2O-3 ceramic particles,stir casting method was employed.In case of Al-20 wt pct Cu alloy （hypoeutectic）,SEM images revealed that primary Al was grown up in the beginning.After that,eutectic phase with well dispersed ceramic particles was formed.In case of eutectic composition,Y-2O-3 particles were uniformly dispersed in the matrix.When the Cu is added into Al up to 40 wt pct （hypereutectic）,primary phase was grown up without any Y-2O-3 ceramic particles in the early stage of solidification.Thereafter, eutectic phase was formed with well dispersed ceramic particles.It can be concluded that Y-2O-3 ceramic particles is mostly dispersed in case of eutectic composition in Al-Cu alloy.展开更多
The g-factors of Ground Rotational Band states of N = 44 isotones 82^Sr, 83^Y, 84^Zr and 85^Nb have been measured by the transient-magnetic-field ion implantation perturbed angular distribution （TMF-IMPAD） method. T...The g-factors of Ground Rotational Band states of N = 44 isotones 82^Sr, 83^Y, 84^Zr and 85^Nb have been measured by the transient-magnetic-field ion implantation perturbed angular distribution （TMF-IMPAD） method. The measured g-factors of 82^Sr increase with the increase of spin I, indicating a proton alignment only. Positive peaks appear in the variation of g-factors with spin for 83^Y and 84^Zzr at spin 21/2^＋ and 10^＋ respectively, indicating a proton alignment followed by a neutron alignment. A negative peak occurs for SSNb at the spin 25/2^＋, indicating a neutron alignment followed by a proton alignment.展开更多
In this Paper,four Pd NaY samples prepared by means of exchanging NaY Zeo-lite with [Pd(NH3)4]2+ under microwave rediation were studied by XPS.The XPS results show that the Pd particles encaged in Y Zeolite can be obt...In this Paper,four Pd NaY samples prepared by means of exchanging NaY Zeo-lite with [Pd(NH3)4]2+ under microwave rediation were studied by XPS.The XPS results show that the Pd particles encaged in Y Zeolite can be obtained.展开更多
基金Project supported by the National Natural Science Foundation of China (50372086)the Ministry of Science and Technology of Chi-na (2006CB601104)
文摘The Y-Eu oxalate precursor was prepared with a homogeneous precipitation method. And the additives, Na2CO3, S, NaCl or their combination, were introduced into the precursor to prepare Y2O3 ：Eu^3＋ red phosphors at 1000 1300 ℃ for 2 h. The effect of molten salts on particle size and luminescent intensity was studied. The experimental results showed that the complex molten salt （Na：CO3 ＋ S ＋ NaCl） was conductive to enhance the luminescent intensity of Y2O3 ：Eu^3＋. The emission intensity of the phosphor prepared with these additives at 1300 ℃ was about 45% higher than that of the one prepared without molten salt, and about 11% higher than that of the corresponding commercial phosphor. Meanwhile, the particle size of Y2O3 ：Eu^3＋ phosphor was controlled effectively with the molten salt.
文摘A series of thermodynamic parameters in formation of ultrafine monodispersed colloidal particles of Y(OH)CO3 were measured, estimated and calculated. The thermodynamic stability of Y(OH)CO3 colloidal particles was studied and discussed by phenomenological model. It is suggested that ultrafine monodispersed colloidal particles of Y(OH)CO3 are stable only in a very narrow temporary supersaturation range ( 1<x<1 .08).
基金Acknowledgement This work was supported financially by Ministry of Commerce, Industry ＆： Energy （MOCIE） through National Mid- and Long-term Atomic Energy R＆D Program.
文摘In the present work,the dispersion casting of Y-2O-3 particles in aluminum-copper alloy was investigated in terms of microstructural changes with respect to Cu contents of 20 （hypo）,33 （eutectic） and 40 （hyper） wt pct by scanning electron microscopy （SEM） and energy dispersive spectroscopy （EDS）.For the fabrication of Al-Cu alloy dispersed Y-2O-3 ceramic particles,stir casting method was employed.In case of Al-20 wt pct Cu alloy （hypoeutectic）,SEM images revealed that primary Al was grown up in the beginning.After that,eutectic phase with well dispersed ceramic particles was formed.In case of eutectic composition,Y-2O-3 particles were uniformly dispersed in the matrix.When the Cu is added into Al up to 40 wt pct （hypereutectic）,primary phase was grown up without any Y-2O-3 ceramic particles in the early stage of solidification.Thereafter, eutectic phase was formed with well dispersed ceramic particles.It can be concluded that Y-2O-3 ceramic particles is mostly dispersed in case of eutectic composition in Al-Cu alloy.
基金supported by National Science Foundation of China (Nos.10435010,109751891)
文摘The g-factors of Ground Rotational Band states of N = 44 isotones 82^Sr, 83^Y, 84^Zr and 85^Nb have been measured by the transient-magnetic-field ion implantation perturbed angular distribution （TMF-IMPAD） method. The measured g-factors of 82^Sr increase with the increase of spin I, indicating a proton alignment only. Positive peaks appear in the variation of g-factors with spin for 83^Y and 84^Zzr at spin 21/2^＋ and 10^＋ respectively, indicating a proton alignment followed by a neutron alignment. A negative peak occurs for SSNb at the spin 25/2^＋, indicating a neutron alignment followed by a proton alignment.
文摘In this Paper,four Pd NaY samples prepared by means of exchanging NaY Zeo-lite with [Pd(NH3)4]2+ under microwave rediation were studied by XPS.The XPS results show that the Pd particles encaged in Y Zeolite can be obtained.
