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121.
122.
Fu-Ken Liu 《Analytica chimica acta》2005,528(2):249-254
This paper demonstrates that capillary electrophoresis (CE) can be employed for characterizing the sizes of nanometer-scale gold particles. We characterized the gold nanoparticles by effecting CE separation using a buffer of SDS (70 mM) and 3-cyclohexylamino-1-propanesulfonic acid (CAPS; 10 mM) at pH 11.0 and an applied voltage of 18 kV and obtained a linear relationship (R2 > 0.99) between electrophoretic mobilities and size for nanoparticles whose diameters fall in the regime from 5.0 ± 0.5 to 41.2 ± 3.3 nm; the relative standard deviations of these electrophoretic mobilities are <0.8%. We evaluated the feasibility of employing these separation conditions for the size characterization by of gold nanoparticle samples that were synthesized by a rapid microwave heating method. We confirmed that this CE method is a valid one for size characterization by comparing the results obtained by CE with those provided by scanning electron microscopy (SEM); a good correlation exists between these two techniques. Our results demonstrate that CE can be employed to accelerate the analysis of the sizes of nanomaterials. 相似文献
123.
Won Young Jung Byung Ho Noh Seung Hee Baek Gun-Dae Lee Seong Soo Park Seong-Soo Hong 《Reaction Kinetics and Catalysis Letters》2007,91(2):223-231
SBA-15 mesoporous material was prepared by microwave-hydrothermal method and was used as support in TiO2-loaded SBA-15 photocatalysts. The physical properties of these particles were investigated. We also examined the activity
of these samples as photocatalysts for the decomposition of orange II. Titania loaded on a silica matrix decreases the surface
area of the support as expected for TiO2 incorporation. For TiO2-loaded SBA-15 photocatalysts, the IR absorption at ∼960 cm−1 commonly accepted as the characteristic vibration of the Ti-O-Si bond. The photocatalytic activity increases with an increase
of the TiO2 loading. 相似文献
124.
M. Katkevičs A. Kontijevskis I. Mutule E. Sūna 《Chemistry of Heterocyclic Compounds》2007,43(2):151-159
A 30-membered library of coumarins has been synthesized in a microwave-assisted Pechmann reaction using neat trifluoroacetic
acid both as an acidic reagent and a reaction medium. Alternatively, polymer-supported sulfonic acid Amberlyst-15 could also
be employed to facilitate the formation of coumarins. The use of a specially-built microwave synthesizer with liquid handling
tools rendered the automated synthesis of a coumarin library feasible.
__________
Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 200–208, February, 2007. 相似文献
125.
微波增压溶样-石墨炉原子吸收光谱法同时测定植物性样品中微量铅镉 总被引:7,自引:2,他引:7
使用微波增压溶样法,将样品用HNO3—HClO4溶解后,用石墨炉原子吸收光谱法同时测定植物性样品中铅和镉。以磷酸二氢铵—硝酸镁作为基体改进剂,可使灰化温度大大提高,克服了基体的干扰。铅和镉的回收率分别为95.3%—104.8%和96.2%—105.5%,RSD分别为4.8%-7.2%和4.3%-7.6%。 相似文献
126.
HUA Guo-Pinga ZHU Xiao-Tongb ZHANG Jin-Pengb XU Jia-Ningb WANG Qianb JI Shun-Junc ZHANG Yongc TU Shu-Jiangb② a 《结构化学》2006,25(5):599-603
1 INTRODUCTION Various quinolone derivatives are known to dis- play interesting biological properties ranging from microbial activity to cytotoxicity[1]. They have been reported as antiviral (HIV-1)[2] and antitumor agents[3] as well as used as tubulin[4], topoisomerase[5] and thrombocyte inhibitors[6]. As a member of the quino- lone family, substituted N-phenyl-2-quinolones re-present the structural basis of many biologically active compounds, such as protein kinase inhibitors, immunodu… 相似文献
127.
改进的微波辅助无溶剂法提取薄荷和陈皮中的挥发油组分 总被引:1,自引:0,他引:1
An improved solvent free microwave extraction, in which a kind of microwave absorption medium (carbonyl iron powder) was used, was applied to the extraction of essential oil from dried menthol mint and orange peel without addition of any solvent and pretreatment. It took much less time of extraction (30 min) than microwave-assisted hydrodistillation (90 min) and conventional hydrodistillation (180 min). The kinds of chemical compositions in essential oil extracted by different methods were almost the same and such improved solvent free microwave extraction can be a feasible way in extraction of essential oil from dried plant materials. 相似文献
128.
N. M. Bogdanovich V. P. Gorelov V. B. Balakireva T. A. Demyanenko 《Russian Journal of Electrochemistry》2005,41(5):576-581
The phase composition and electroconduction in air of solid electrolytes (Ce0.8Sm0.2)1 − x
CuxO2 − δ (CSCu), where x = 0, 2, 5, 10, and 20 mol % and which are synthesized using the ceramic technology, are studied. Adding an additive of CuO lowers the CSCu sintering temperature by 100– 200°C and leads to the formation of single-phase solid solutions of a fluorite type up to x = 10 mol %. The electroconductivity of the CSCu electrolytes remains practically invariant upon adding up to 5 mol % Cu and equals 0.089–0.095 and 0.017–0.021 S cm−1 at 800 and 600°C. The sintering, adhesion, and electroconductance of composite cathodes based on La0.8Sr0.2MnO3 with 40% CSCu and their electrochemical behavior in air in the temperature interval 900–1000°C on carrying electrolyte Zr0.9Y0.1O1.95 with a CSCu sublayer containing 2 mol % Cu are studied.__________Translated from Elektrokhimiya, Vol. 41, No. 5, 2005, pp. 656–661.Original Russian Text Copyright © 2005 by Bogdanovich, Gorelov, Balakireva, Dem’yanenko. 相似文献
129.
130.
A. M. Wrobel B. Lamontagne M. R. Wertheimer 《Plasma Chemistry and Plasma Processing》1988,8(3):315-329
We have investigated O2/CF4 plasma etching of five commercial polymers: polyimide, polyamide, polyethylene terephthalate, polycarbonate and cured epoxy resin. A new large-area microwave plasma apparatus has been used in this work, but the same apparatus can also be used as a capacitively coupled radiofrequency (13.56 MHz) discharge reactor. The effect of operating parameters such as pressure, etchant gas composition, excitation frequency and sample temperature upon etch kinetics has been examined. We have observed distinct maxima in the etch rate as functions of pressure and CF4 concentration. Activation, energies evaluated from the Arrhenius plots fall in the range 0.04-0.2 eV, in agreement with data in the literature. Dry etch susceptibility of a given polymer correlates strongly with the degree of unsaturation in the polymer's structure 相似文献