Antioxidant Activity of Different Solvent Extracts of Blumea Megacephala in Vitro

[Objectives] The aim was to study the antioxidant activity of different solvent extracts of Blumea Megacephala in vitro. [Methods] The removal rates of DPPH free radicals and ABTS free radicals and the reduction capacity of Fe^(3+) by ethanol extract( EE),acetone extract( AE) and ethyl acetate extract( EAE) of Blumea Megacephala were detected. [Results]The three extracts of Blumea Megacephala had certain antioxidant activity,of which the antioxidant activity of ethyl acetate extract was the strongest and has great potential for development.[Conclusions]The study can provide scientific reference for the deep research on the antioxidant activity of Blumea Megacephala.

Analysis of the Volatile Components of Polygonum chinense L.Extracted with Different Solvents by GC-MS

[Objectives]This study was conducted to investigate the volatile components of Polygonum chinense L.[Methods]The volatile components of the methanol extract,ethyl acetate extract,chloroform extract and petroleum ether extract of P.chinense were analyzed and determined by gas chromatography.[Results]The volatile components of the methanol extract from P.chinense were the most,and phenolic acids and ketones accounted for a relatively high proportion,among which pyrogallic acid had the highest content.The ethyl acetate extract contained the second most volatile components,mostly acids and esters,of whichβ-sitosterol had the highest content;the chloroform and petroleum ether extracts had relatively few types of volatile components,most of which were alkanes,and the content ofγ-sitosterol shared by the two was the highest.The common substances of the four extracts were palmitic acid and phytol.[Conclusions]This study provides a theoretical basis for the quality evaluation of P.chinense and a scientific basis for its resource development.

Organic Solar Cells Flexible P3HT：PCBM Thin Film and Improving Its Performance

Organic solar cells （OSCs） is a new generation of solar cells have emerged as an alternative to conventional Si-based solar cells owing to their advantages of low cost, ease of fabrication and their potential for the manufacture of flexible and large area solar cells. So we chose that part to beginning study of the material and all parameters effects in environmental condition because the solar cell working in environment. In this study the fabrication of poly（3-hexylthiophene） （P3HT） and [6,6]-phenyl C61-butyric acid methyl ester （PCBM） blend flexible thin film using spin coating was reported. Process parameters like solvent, electron donor to acceptor ratio, concentration and temperature were also studied. We used solvent systems to make active layer of P3HT：PCBM composite and PEDOT：PSS as a buffer layer. Highest absorption was obtained for the flexible thin film made with 1：1 and 1：0.75 ratio of P3HT to PCBM. Chloroform solvent in 40 gm/ml concentration at 90 ~C was the optimum conditions to make flexible device.

Effect of solvent on luminescence properties of re-dispersible LaF_3:Ln^(3+)(Ln^(3+)=Eu^(3+),Dy^(3+),Sm^(3+) and Tb^(3+)) nanoparticles

LaF3：Ln3＋ （Eu3＋, Dy3＋, Sm3＋ and Zb3＋） nanoparticles were prepared in different solvents such as water, EG （ethylene gly- col）, DMSO （dimethyl sulfoxide） and their mixed solvents at a relatively low temperature of 150 ~C by simple chemical route. All the prepared samples showed hexagonal phase and exhibited spherical morphology. The highest ltmainescence intensity was observed for the samples prepared in EG than the samples prepared in other solvents. However, the sample prepared in water showed anomalously higher luminescence intensity than that of the sample prepared in DMSO.