A novel orange-red emitting Ba3 Y4 O9：Sm^（3＋） phosphors were prepared by a high temperature solidstate reaction in air. X-ray diffraction（XRD）, photoluminescence spectra, fluorescence decay and temperature-depen...A novel orange-red emitting Ba3 Y4 O9：Sm^（3＋） phosphors were prepared by a high temperature solidstate reaction in air. X-ray diffraction（XRD）, photoluminescence spectra, fluorescence decay and temperature-dependent emission spectra were utilized to characterize the structure and luminescence properties. The results show that the excitation spectrum includes a series of linear peaks at350, 367, 382, 410, 424, 445, 470 and 495 nm, respectively. Under 410 nm excitation, the emission peaks were located at 574 nm（~4 G（5/2）-~6 H（5/2））, 608 nm（~4 G（5/2）-~6 H（7/2））,659 nm（~4 G（5/2）-~6 H（9/2）） and722 nm（~4 G（5/2）-~6 H（11/2））, respectively. The concentration quenching occurs when x equals 0.08 for Ba3 Y（4-x）O9：xSm^（3＋） phosphor and its mechanism is ascribed to the dipole-dipole interaction. The chromaticity coordinates of Ba3 Y（3.92）O9：0.08 Sm^（3＋） phosphor are in the orange-red region. The temperature-dependent study shows that this phosphor has excellent luminescence thermal-stability.And the luminescence intensity of Ba3 Y（3.92）O9：0.08 Sm^（3＋） phosphor at 473 K only declines by about25.75% of its initial intensity. The experimental data indicate that Ba3 Y4 O9：Sm^（3＋） phosphor may be promising as an orange-red emitting phosphor for white light emitting diodes.展开更多
Bacillus spp.has been proven to be critical for the quality of many fermented foods,but as one of the domain bacteria,its effect on the quality of Yibin Yacai has not been fully addressed.Herein,the effects of inocula...Bacillus spp.has been proven to be critical for the quality of many fermented foods,but as one of the domain bacteria,its effect on the quality of Yibin Yacai has not been fully addressed.Herein,the effects of inoculation of Bacillus subtilis Y4 on the physicochemical properties,flavor metabolism and microbial community changes of Yibin Yacai for three-month solid-state fermentation were investigated.The results showed that inoculation of B.subtilis Y4 could reduce the pH and salinity of Yibin Yacai,accelerate the consumption of nitrite,promote the growth of Lactobacillus and the production of sweet amino acid,and inhibit pathogenic microorganisms at the late fermentation stage.During solid-state fermentation,the dominant fungus Cystofilobasidium was positively correlated with most volatile flavor substances,which were indirectly affected by B.subtilis Y4.Furthermore,compared to spontaneous fermented Yibin Yacai,inoculation of B.subtilis Y4 promoted the production of alkenes and made the peak of ester content appear earlier.These results indicated that inoculation of B.subtilis Y4 for solid-state fermentation could improve the quality and taste of Yibin Yacai,and shorten the fermentation time.展开更多
基金supported by the National Key Research and Development Program of China(2016YFB0701003)Key Program of the Frontier Science of the Chinese Academy of Sciences(YZDY-SSW-JSC018)+1 种基金National Natural Science Foundation of China(51402288)Natural Science Foundation of Liaoning Province(201602674)
文摘A novel orange-red emitting Ba3 Y4 O9：Sm^（3＋） phosphors were prepared by a high temperature solidstate reaction in air. X-ray diffraction（XRD）, photoluminescence spectra, fluorescence decay and temperature-dependent emission spectra were utilized to characterize the structure and luminescence properties. The results show that the excitation spectrum includes a series of linear peaks at350, 367, 382, 410, 424, 445, 470 and 495 nm, respectively. Under 410 nm excitation, the emission peaks were located at 574 nm（~4 G（5/2）-~6 H（5/2））, 608 nm（~4 G（5/2）-~6 H（7/2））,659 nm（~4 G（5/2）-~6 H（9/2）） and722 nm（~4 G（5/2）-~6 H（11/2））, respectively. The concentration quenching occurs when x equals 0.08 for Ba3 Y（4-x）O9：xSm^（3＋） phosphor and its mechanism is ascribed to the dipole-dipole interaction. The chromaticity coordinates of Ba3 Y（3.92）O9：0.08 Sm^（3＋） phosphor are in the orange-red region. The temperature-dependent study shows that this phosphor has excellent luminescence thermal-stability.And the luminescence intensity of Ba3 Y（3.92）O9：0.08 Sm^（3＋） phosphor at 473 K only declines by about25.75% of its initial intensity. The experimental data indicate that Ba3 Y4 O9：Sm^（3＋） phosphor may be promising as an orange-red emitting phosphor for white light emitting diodes.
基金supported by the Sichuan Science and Technology Program(no.2019YFG0164).
文摘Bacillus spp.has been proven to be critical for the quality of many fermented foods,but as one of the domain bacteria,its effect on the quality of Yibin Yacai has not been fully addressed.Herein,the effects of inoculation of Bacillus subtilis Y4 on the physicochemical properties,flavor metabolism and microbial community changes of Yibin Yacai for three-month solid-state fermentation were investigated.The results showed that inoculation of B.subtilis Y4 could reduce the pH and salinity of Yibin Yacai,accelerate the consumption of nitrite,promote the growth of Lactobacillus and the production of sweet amino acid,and inhibit pathogenic microorganisms at the late fermentation stage.During solid-state fermentation,the dominant fungus Cystofilobasidium was positively correlated with most volatile flavor substances,which were indirectly affected by B.subtilis Y4.Furthermore,compared to spontaneous fermented Yibin Yacai,inoculation of B.subtilis Y4 promoted the production of alkenes and made the peak of ester content appear earlier.These results indicated that inoculation of B.subtilis Y4 for solid-state fermentation could improve the quality and taste of Yibin Yacai,and shorten the fermentation time.
