Room- and variable-temperature photoluminescence from 3C-SiC aloetic-shaped nanowires was presented. The SiC nanowires were prepared on Si(100) substrates by the reaction of methane with silicon dioxide. Scanning electron microscope (SEM) and X-ray diffraction (XRD) are used to characterization the nanowires. A green photoluminescence (PL) band centered at 2.34 eV is observed in the nanowires at room temperature. The results from variable-temperature photoluminescence show anomalous temperature dependencies of the spectral characteristics. The emission intensity increases with decreasing temperature until reaching an intensity maximum at about 155 K, then it decreases at lower temperatures. The emission energy has little shift following temperature variations. The anomalous temperature dependencies of PL results may be explained by quantum confinement effect and phonon participation in the emission process.
Some traditional acidic ionic liquids (AILs) have shown great catalytic potential in esterification; meanwhile, the design and application of more new AILs are expected at present.Tropine-based functionalized acidic ionic liquids (FAILs) were synthesized to realize esterification catalysis for the first time; with aspirin synthesis as the template reaction, key influences on the substrate conversion and product yield of the synthesis, such as IL type, ratio of salicylic acid to acetic anhydride, temperature, reaction time and amount of IL, were investigated. The new tropine-based FAILs exhibited excellent performance in catalytic synthesis of aspirin with 88.7% yield and 90.8% selectivity. Multiple recovery and re-usage of N-(3-propanesulfonic acid) tropine is the cation, and p-toluenesulfonic acid is the anion. ([Trps][OTs]) shows satisfactory results. When [Trps][OTs] was used to catalyze different esterification reactions, it also showed good results. The above studies proved that ionic liquid [Trps][OTs] could serve as an ideal green solvent for esterification reaction, which serves as a suitable substitute for current catalysts.
With the emergence of fused ring electron acceptors, the power conversion efficiency of organic solar cells reached 19%. In comparison with the electron donor and acceptor materials progress, the development of cathode interlayers lags. As a result, charge extraction barriers, interfacial trap states, and significant transport resistance may be induced due to the unfavorable cathode interlayer, limiting the device performances. Herein, a hybrid cathode interlayer composed of PNDIT-F3N and PDIN is adopted to investigate the interaction between the photoexcited acceptor and cathode interlayer. The state of art acceptor Y6 is chosen and blended with PM6 as the active layer. The device with hybrid interlayer, PNDIT-F3N:PDIN (0.6:0.4, in wt%), attains a power conversion efficiency of 17.4%, outperforming devices with other cathode interlayer such as NDI-M, PDINO, and Phen-DPO. It is resulted from enhanced exciton dissociation, reduced trap-assisted recombination, and smaller transfer resistance. Therefore, the hybrid interlayer strategy is demonstrated as an efficient approach to improve device performance, shedding light on the selection and engineering of cathode interlayers for pairing the increasing number of fused ring electron acceptors.
Core Ideas We assessed the movement capacity of different P. Banding P fertilizer in suboptimal placement reduced wheat yield with monocalcium phosphate. Diammonium phosphate compensated for the reduction in wheat yield due to suboptimal placement. Banding of P can increase P availability to crops. Our objective was to determine if banding two forms of P fertilizer at multiple distances from the seed can improve wheat ( Triticum aestivum L.) growth and P uptake vs. broadcast P fertilizer application. Waters‐soluble and Ca 2 – P concentrations in soil was greater near the point of P placement when monocalcium phosphate was used compared to diammonium phosphate, while the opposite result was found when the P diffusion distance was greater than 2 cm from the P placement. Another field experiment with four application strategies (broadcasting P, banding P under the wheat row, and banding P 5 and 12 cm from the wheat row) and two P forms was conducted over 2 yr. Banding P under the wheat row increased wheat yield and P uptake regardless of the P form compared to broadcasting P. Banding 12 cm from the row resulted in a 6.0% reduction in wheat yield for monocalcium phosphate compared to broadcasting P. Banding diammonium phosphate 5 or 12 cm from the row provided yield compensations over monocalcium phosphate. Dry matter at regreening was significantly depressed for banding 5 or 12 cm from the row with monocalcium phosphate application relative to broadcasting P, while there was compensatory growth for banding 5 cm from the row after regreening. Root length proliferated with diammonium phosphate than with monocalcium phosphate regardless of band placement. Diammonium phosphate should not be placed more than 5 cm from the row to ensure maximum P uptake potential.
Pharmacognosy Magazine,2013,9,35,250-254.DOI:10.4103/0973-1296.113282Published:June 2013Type:Original ArticleAuthors:Wang Yan, Luo Ji, Song Hang, and Yao Shun Author(s) affiliations:Wang Yan, Luo Ji, Song Hang, Yao Shun Department of Pharmaceutical and Biological Engineering, Sichuan University, Chengdu, China Abstract:Background: Rhizoma dioscoreae nipponicae is a perennial herb and its roots have been widely used in Traditional Chinese Medicine (TCM). Objective: To develop and optimize the extraction and hydrolysis technology of diosgenin from Rhizoma dioscoreae nipponicae. Materials and Methods: 1-methyl-3-(3-sulfopropyl)-imidazolium hydrogen sulfate ([PSMIM]HSO 4 ), as a kind of functional ionic liquid, replaced inorganic acid, and was used in a one-step ultrasonic extraction and hydrolysis for the preparation of diosgenin (the aglycone of dioscin and an important precursor chemical in the pharmaceutical industry) from Rhizoma dioscoreae nipponicae , for the first time. The effects of various factors were evaluated. The obtained product was studied using high performance liquid chromatography (HPLC). Results: About 6.35 mg of diosgenin could be obtained from 2.0 g of raw material. Reusability and recycling of the ionic liquid were validated with fairly good results. The ionic liquid solution was reused four times, and the final extraction efficiency only decreased by 5%. Conclusion: In virtue of the obvious advantages of the green extraction and catalytic solvent, with further study, it is believed that this new one-step preparative method promises to replace the traditional methods. Keywords:Diosgenin, Extraction, hydrolysis, ionic liquidView:PDF (1.41 MB) Full Text
'/%3e%3cuse xlink:href='%23a' transform='rotate(23.036 .093 25.536)'/%3e%3cuse xlink:href='%23a' transform='rotate(45.87 1.273 16.18)'/%3e%3cuse xlink:href='%23a' transform='rotate(69.945 .996 12.078)'/%3e%3cuse xlink:href='%23a' transform='rotate(20.66 -19.689 31.932)'/%3e%3c/svg%3e)