[Objectives] To optimize the extraction process of polysaccharides from leaves of Dendrobium officinale. [Methods]The polysaccharides from D. officinale were extracted by internal boiling method. The extraction rate o...[Objectives] To optimize the extraction process of polysaccharides from leaves of Dendrobium officinale. [Methods]The polysaccharides from D. officinale were extracted by internal boiling method. The extraction rate of polysaccharides from D. officinale was studied.Based on the single factor experiment,the L_9( 3~3) orthogonal experiment was designed to optimize the extraction process of polysaccharides from D. officinale. [Results]The optimum process for extracting polysaccharides from D. officinale by internal boiling method was as follows:1. 00 g of D. officinale powder was desorbed with 6. 0 mL of 20% ethanol for 20 min,35. 0 mL of 90℃ water was rapidly added,and the extraction time was 5 min. [Conclusions] Under this condition,the extraction rate of polysaccharides from D. officinale was 12. 31%,which was 3. 75 percentage points higher than that of traditional reflux extraction.展开更多
A series of single phase,warm white light emitting phosphors,Gd(P_(x)V_(1−x))O_(4):y at%Sm^(3+),with 1 at%Bi^(3+) doping concentration were synthesized by high temperature solid state method in this work.The experimen...A series of single phase,warm white light emitting phosphors,Gd(P_(x)V_(1−x))O_(4):y at%Sm^(3+),with 1 at%Bi^(3+) doping concentration were synthesized by high temperature solid state method in this work.The experimental results indicate broadband cyan emission of Bi^(3+)and characteristic orange-red emission of Sm^(3+)can be effectively tuned by changing the ratios of PO^(3−)_(4)/VO^(3−)_(4) in Gd(P_(x)V_(1−x))O_(4):1 at%Sm^(3+),1 at%Bi^(3+),and the energy transfer process among VO^(3−)_(4),Sm^(3+),Bi^(3+) also can be adjusted.Based on this,warm white light emitting can be realized by further optimizing the doping concentration of Sm^(3+) in the phosphors.At 423 K,the PL intensity of Gd(P_(0.7)V_(0.3))O_(4):2 at%Sm^(3+),1 at%Bi^(3+) remains~84.3%of the initial value at 293 K,while the measured quantum efficiency is 67.8%.EL spectrum analysis results of the fabricated white light emitting diode(wLED)based on a 310 nm UV-chip and Gd(P_(0.7)V_(0.3))O4:2 at%Sm^(3+),1 at%Bi^(3+)phosphors imply low correlated color temperature(3132 K)and appropriate color-rending index(R_(a)=82.7).These results demonstrate that Gd(P_(0.7)V_(0.3))O4:2 at%Sm^(3+),1 at%Bi^(3+)is a good candidate for manufacturing UV-activated warm white light emitting diodes.展开更多
基金Supported by Key Discipline Independent Project for Chemical Engineering of Guangxi Colleges and Universities(2015KLOG18)Natural Science Foundation Project of Guangxi Zhuang Autonomous Region(2017GXNSFFA198007Key Science and Technology Project of Guangxi(Gui Ke AA17202010)
文摘[Objectives] To optimize the extraction process of polysaccharides from leaves of Dendrobium officinale. [Methods]The polysaccharides from D. officinale were extracted by internal boiling method. The extraction rate of polysaccharides from D. officinale was studied.Based on the single factor experiment,the L_9( 3~3) orthogonal experiment was designed to optimize the extraction process of polysaccharides from D. officinale. [Results]The optimum process for extracting polysaccharides from D. officinale by internal boiling method was as follows:1. 00 g of D. officinale powder was desorbed with 6. 0 mL of 20% ethanol for 20 min,35. 0 mL of 90℃ water was rapidly added,and the extraction time was 5 min. [Conclusions] Under this condition,the extraction rate of polysaccharides from D. officinale was 12. 31%,which was 3. 75 percentage points higher than that of traditional reflux extraction.
基金Project supported by the National Natural Science Foundation of China(51972181,61705231)Major Basic Research Projects of Shandong Natural Science Foundation(ZR2018ZB0650)+2 种基金China Postdoctoral Science Foundation(2015M580573)High Quality Course Construction Project of Graduate Education in Shandong Province(SDYKC18051)Postgraduate Tutor Ability Improvement Project of Shandong Province(SDYY17179)。
文摘A series of single phase,warm white light emitting phosphors,Gd(P_(x)V_(1−x))O_(4):y at%Sm^(3+),with 1 at%Bi^(3+) doping concentration were synthesized by high temperature solid state method in this work.The experimental results indicate broadband cyan emission of Bi^(3+)and characteristic orange-red emission of Sm^(3+)can be effectively tuned by changing the ratios of PO^(3−)_(4)/VO^(3−)_(4) in Gd(P_(x)V_(1−x))O_(4):1 at%Sm^(3+),1 at%Bi^(3+),and the energy transfer process among VO^(3−)_(4),Sm^(3+),Bi^(3+) also can be adjusted.Based on this,warm white light emitting can be realized by further optimizing the doping concentration of Sm^(3+) in the phosphors.At 423 K,the PL intensity of Gd(P_(0.7)V_(0.3))O_(4):2 at%Sm^(3+),1 at%Bi^(3+) remains~84.3%of the initial value at 293 K,while the measured quantum efficiency is 67.8%.EL spectrum analysis results of the fabricated white light emitting diode(wLED)based on a 310 nm UV-chip and Gd(P_(0.7)V_(0.3))O4:2 at%Sm^(3+),1 at%Bi^(3+)phosphors imply low correlated color temperature(3132 K)and appropriate color-rending index(R_(a)=82.7).These results demonstrate that Gd(P_(0.7)V_(0.3))O4:2 at%Sm^(3+),1 at%Bi^(3+)is a good candidate for manufacturing UV-activated warm white light emitting diodes.
