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962.
Dongxia Nie Ping Li Dan Zhang Tianshu Zhou Ying Liang Guoyue Shi 《Electrophoresis》2010,31(17):2981-2988
In this article, a carbon disk electrode modified with mesoporous carbon material (CMK‐3) was used in CE with amperometric detection system for the simultaneous determination of four types of important nitroaromatic compounds, including 2,4,6‐trinitrotoluene (TNT), 1,3,5‐trinitrobenzene (TNB), 2,4‐dinitrotoluene (DNT) and 1,3‐dinitrobenzene (DNB). Compared with the bare carbon electrode, the CMK‐3 modified electrode greatly improved the sensitivity at a relatively positive detection potential due to its excellent electrocatalytic activities, high conductivity and large effective surface area. The four analytes could be well separated and detected within 480 s. A good linear response was obtained for TNB, DNB, TNT and DNT from 8.4 to 5.0×103 μg/L, with correlation coefficients higher than 0.9992. And the detection limits were established between 3.0 and 4.7 μg/L for the four investigated nitroaromatic compounds (S/N=3). The CMK‐3‐modified electrode was successfully employed to analyze coking wastewater, tap water and river samples with recoveries in the range of 94.8–109.0%, and RSDs less than 5.0%. The presented results demonstrated that the CMK‐3‐modified carbon electrode used in CE with amperometric detection was of convenient preparation, high sensitivity and good repeatability, which could be employed in the rapid determination of practical samples. 相似文献
963.
The wetting and evaporation behaviors of molten Mg drops on pressureless-sintered SiC surfaces were studied in a flowing Ar atmosphere at 973-1173 K by an improved sessile drop method. The initial contact angles are between 83° and 76°, only mildly depending on temperature. The formation of a ridge at the triple junction as a result of reaction between molten Mg and the SiO2 film on the SiC surface pins the triple line and leads to a constant contact diameter mode during the entire evaporation process. Moreover, the diffusion coefficients of the Mg vapor at different temperatures were evaluated based on a simple model. 相似文献
964.
在水相中,FeCl3催化对甲基苯胺聚合合成了对甲基苯胺三分子聚合物——(N,N′E,N,N′E)-N,N′-(2-氨基-5-甲基-2,5-环己二烯-1,4-二亚基)二(4-甲基苯胺)(1),其结构经X-射线单晶衍射仪表征。1属六方晶系,R3空间群,晶胞参数:a=21.116(2),b=21.116(2),c=10.364(2),α=90°,β=90°,γ=120°,Mr=315.41,Z=9,V=4002.1(10)3,Dc=1.178 g.cm-3,μ=0.070 mm-1,λ=0.710 73,F(000)=1 512,R=0.067 8,wR=0.112 6。 相似文献
965.
966.
Lucia Dančová Igor Bodík Andrea Blšťáková Zuzana Jakubčová Miloslav Drtil 《Chemical Papers》2008,62(5):451-457
Possibilities of membrane technology and the use of membrane processes in wastewater treatment were investigated. The main
focus was the monitoring of the starting phase of a domestic wastewater treatment plant. Experimental part of the study was
realized at the municipal wastewater treatment plant (WWTP) Devínska Nová Ves — Bratislava during the period from February
2005 to September 2006. The system was stable without any external chemical treatment of the membrane modules and the permeate
quality was very high. Observed decrease of COD and BOD5 values ranged between 91 % and 98 %. The process of nitrification was very successful considering its high efficiency (>
95 %).
Presented at the 34th International Conference of the Slovak Society of Chemical Engineering, Tatranské Matliare, 21–25 May
2007. 相似文献
967.
968.
Jingquan Sha Jun Peng Shujing Zhou Min Zhu Ling Han Dan Chen 《Journal of Cluster Science》2008,19(3):499-509
Two new bivanadyl capped Keggin polyoxometalate-based inorganic–organic hybrid compounds, [M(2,2′-bipy)2(H2O)]2[AsMo12O40(VO)2]}(M = Co 1, Zn 2; bipy = bipyridine), have been synthesized under hydrothermal conditions by directly using Li3[AsMo12O40] · nH2O as starting materials. Single crystal X-ray analysis revealed that compounds 1 and 2 were isostructural, consisting of a neutral bivanadyl capped Keggin POMs bigrafted by [M(2,2′-bipy)2(H2O)]2+ fragments. Other characterizations by elemental analysis, IR spectra, XPS spectra, power X-ray diffraction and TG analysis
were also described in the paper. The study of the electrochemical properties of compounds 1 and 2 exhibit similar redox behaviors, undergoing three two-electron reversible redox processes, and the electrocatalysis of 1 has also been studied in detail.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
969.
Capillary electrophoresis using 1-butyl-3-methylimidazolium tetrafluoroborate as background electrolyte for the separation and determination of 11 amino acids was studied. Several parameters, such as ionic liquid concentration, pH of background electrolyte and applied voltage, were optimized. Amino acids were derived with Sanger’s reagent (2,4-dinitrofluorobenzene) and the detection was performed by an ultraviolet absorption detector at 360 nm. Under selected conditions, 11 amino acids were completely separated within 16 min. The RSD values of integrated areas and migration times are <3.03 and <1.64%, respectively. The electroosmotic flow can be influenced by imidazolium cation, and the association between the imidazolium cation and the derived amino acids plays an important role in the separation mechanism. This method not only provides an approach for the separation and determination of amino acids, but is also an extension of the ionic liquid application to capillary electrophoresis. 相似文献
970.
借助隐预解算子技巧来研究广义多值拟变分包含的灵敏性分析.所得结果改进、推广和统一了文献中的一些结果. 相似文献