A novel Eu^(3+)-doped fluorapatite red phosphor Ca_(2)Y_(8)(BO_(4))_(2)(SiO_(4))_(4)F_(2)Eu^(3+)with pure phase was synthesized in this study.Density functional theory(DFT)calculation and diffuse reflection spectrum a...A novel Eu^(3+)-doped fluorapatite red phosphor Ca_(2)Y_(8)(BO_(4))_(2)(SiO_(4))_(4)F_(2)Eu^(3+)with pure phase was synthesized in this study.Density functional theory(DFT)calculation and diffuse reflection spectrum analysis reveal its potential as a matrix for phosphors excited by ultraviolet light.Eu^(3+)has a^(7)F_(0)→^(5)L_(6)transition at 394 nm,and the prepared phosphor exhibits a high emission intensity at 614 nm,which may be attributed to the^(5)D_(0)-^(7)F_(2)energy transition at the lower symmetry site of Eu^(3+).The optimal doping concentration of the phosphor is determined to be 11 mol%,with concentration quenching attributed to the exchange interaction mechanism.The overall color purity of the phosphor is up to 99.88%,with an internal quantum efficiency as high as 91.15%.Notably,Ca_(2)Y_(8)(BO_(4))_(2)(SiO_(4))_(4)F_(2):11 mol%Eu^(3+)(CYBSF:11 mol%Eu^(3+))phosphors exhibit good thermal stability,with a thermal quenching temperature(T1/2)of 552 K and the intensity of emission at 423 K still at 88.89%of that at 298 K.The activation energy of the phosphor is up to 0.30287 eV.Its comprehensive luminescence performance surpasses that of commercial red phosphor,making it suitable for near ultraviolet excited warm white light emitting diode(NUV-WLED)with a high color rendering index(Ra=82)and a correlated color temperature(CCT)of 4339 K.Moreover,the phosphor achieves latent fingerprint visualization and anti-counterfeiting ink on different material surfaces:glass,aluminum foil,plastic and paper.Overall,the fluorapatite CYBSF:11 mol%Eu^(3+)phosphor holds great potential for multimodal applications due to its high quantum efficiency and good thermal stability.展开更多
Solubilities and properties (density, conductivity and pH value) of solutions in the quaternary system Li +,K +//CO 2- 3,B 4O 2- 7-H 2O at 288 K were experimentally studied with the isothermal equilibrium method. The ...Solubilities and properties (density, conductivity and pH value) of solutions in the quaternary system Li +,K +//CO 2- 3,B 4O 2- 7-H 2O at 288 K were experimentally studied with the isothermal equilibrium method. The phase diagram of the system consisted of two invariant points E and F, five univariant curves, and four crystallization fields that belonged to K 2CO 3·3/2H 2O,Li 2 B 4O 7·3H 2O, K 2 B 4O 7 ·4H 2O and Li 2CO 3. The composition of the solution corresponding to E was w(CO 2- 3)=2.27 %, w(B 4O 2- 7) =6.05 %, w(K + ) =4.30%,w(Li + )=0.30 % and the equilibrium solids were Li 2 B 4O 7· 3H 2O+K 2 B 4O 7·4H 2O+Li 2CO 3;The composition of the solution for F was w(CO 2- 3) =22.45%,w(B 4O 2- 7)=1.88%,w(K + )=29.96%,w(Li + )=0.03% and the equilibrium solids were K 2CO 3·3/2H 2O+ K 2 B 4O 7·4H 2O+Li 2CO 3. K 2CO 3 possesses strong salting-out effect on K 2 B 4O 7,Li 2CO 3 and Li 2 B 4O 7.展开更多
[Objective]The study aimed to screen the starch-degrading bacterium in bagasse and carry on the identification of strains s2g5-1 and s3g4-8.[Method]By using a variety of selective media,varieties of starch degrading b...[Objective]The study aimed to screen the starch-degrading bacterium in bagasse and carry on the identification of strains s2g5-1 and s3g4-8.[Method]By using a variety of selective media,varieties of starch degrading bacterium were isolated from the sugar cane bagasse form different stages of natural fermentation,then,primary screening and secondary screening were performed.[Result] Starch-degrading strains s2g5-1 and s3g4-8 were screened,and they were identified as Bacillus amyloliquefaciens according to their morphological,physiological,biochemical and molecular characteristics.[Conclusion]The research provided theoretical basis for factory application of bagasse.展开更多
基金supported by the National Natural Science Foundation of China(52372013)Natural Science Foundation of Shanghai(22ZR1460600)。
文摘A novel Eu^(3+)-doped fluorapatite red phosphor Ca_(2)Y_(8)(BO_(4))_(2)(SiO_(4))_(4)F_(2)Eu^(3+)with pure phase was synthesized in this study.Density functional theory(DFT)calculation and diffuse reflection spectrum analysis reveal its potential as a matrix for phosphors excited by ultraviolet light.Eu^(3+)has a^(7)F_(0)→^(5)L_(6)transition at 394 nm,and the prepared phosphor exhibits a high emission intensity at 614 nm,which may be attributed to the^(5)D_(0)-^(7)F_(2)energy transition at the lower symmetry site of Eu^(3+).The optimal doping concentration of the phosphor is determined to be 11 mol%,with concentration quenching attributed to the exchange interaction mechanism.The overall color purity of the phosphor is up to 99.88%,with an internal quantum efficiency as high as 91.15%.Notably,Ca_(2)Y_(8)(BO_(4))_(2)(SiO_(4))_(4)F_(2):11 mol%Eu^(3+)(CYBSF:11 mol%Eu^(3+))phosphors exhibit good thermal stability,with a thermal quenching temperature(T1/2)of 552 K and the intensity of emission at 423 K still at 88.89%of that at 298 K.The activation energy of the phosphor is up to 0.30287 eV.Its comprehensive luminescence performance surpasses that of commercial red phosphor,making it suitable for near ultraviolet excited warm white light emitting diode(NUV-WLED)with a high color rendering index(Ra=82)and a correlated color temperature(CCT)of 4339 K.Moreover,the phosphor achieves latent fingerprint visualization and anti-counterfeiting ink on different material surfaces:glass,aluminum foil,plastic and paper.Overall,the fluorapatite CYBSF:11 mol%Eu^(3+)phosphor holds great potential for multimodal applications due to its high quantum efficiency and good thermal stability.
文摘Solubilities and properties (density, conductivity and pH value) of solutions in the quaternary system Li +,K +//CO 2- 3,B 4O 2- 7-H 2O at 288 K were experimentally studied with the isothermal equilibrium method. The phase diagram of the system consisted of two invariant points E and F, five univariant curves, and four crystallization fields that belonged to K 2CO 3·3/2H 2O,Li 2 B 4O 7·3H 2O, K 2 B 4O 7 ·4H 2O and Li 2CO 3. The composition of the solution corresponding to E was w(CO 2- 3)=2.27 %, w(B 4O 2- 7) =6.05 %, w(K + ) =4.30%,w(Li + )=0.30 % and the equilibrium solids were Li 2 B 4O 7· 3H 2O+K 2 B 4O 7·4H 2O+Li 2CO 3;The composition of the solution for F was w(CO 2- 3) =22.45%,w(B 4O 2- 7)=1.88%,w(K + )=29.96%,w(Li + )=0.03% and the equilibrium solids were K 2CO 3·3/2H 2O+ K 2 B 4O 7·4H 2O+Li 2CO 3. K 2CO 3 possesses strong salting-out effect on K 2 B 4O 7,Li 2CO 3 and Li 2 B 4O 7.
基金Supported by the Central Public-interest Scientific Institution Basal Research Fund(2008hzs1J021,2009hzs1J033)~~
文摘[Objective]The study aimed to screen the starch-degrading bacterium in bagasse and carry on the identification of strains s2g5-1 and s3g4-8.[Method]By using a variety of selective media,varieties of starch degrading bacterium were isolated from the sugar cane bagasse form different stages of natural fermentation,then,primary screening and secondary screening were performed.[Result] Starch-degrading strains s2g5-1 and s3g4-8 were screened,and they were identified as Bacillus amyloliquefaciens according to their morphological,physiological,biochemical and molecular characteristics.[Conclusion]The research provided theoretical basis for factory application of bagasse.
