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11.
S. Cattarin M.M. Musiani U. Casellato P. Guerriero R. Bertoncello 《Journal of Electroanalytical Chemistry》1995,380(1-2)
In+As+Sb alloys have been deposited onto Ni and Ti cathodes from tartaric acid solutions at pH 2. Homogeneous deposits of composition suitable for achieving InAsxSb1−x can be obtained from this medium. The As-to-Sb ratio can be controlled by properly selecting solution composition and deposition potential.X-ray photoelectron spectroscopy and X-ray diffraction analyses show that formation of III–V compounds occurs at room temperature. In reacts preferentially with As rather than with Sb, but crystalline phases formed at room temperature are Sb-rich. After annealing the In+As+Sb alloys at 250°C, the composition calculated from cell parameters appears similar to that measured by energy-dispersive X-ray analysis, suggesting that the entire deposit has been converted into the InAsxSb1−x crystalline phase. 相似文献
12.
J.W. Guthrie M.S.A. Salam C.A. Murimboh C.L. Chakrabarti D.C. Grégoire 《Analytica chimica acta》2005,528(2):205-218
Complexation of Ni(II), Cu(II), Zn(II), and Cd(II) by dissolved organic carbon (DOC) in some freshwater lakes in Rouyn-Noranda, Québec, Canada, where they were impacted by effluents from a nearby copper smelter, was measured by kinetic and equilibrium methods using cathodic and anodic stripping voltammetry. The measured free-metal-ion and labile metal-complex concentrations were compared with the predictions made by a widely-used computer speciation model, the Windermere Humic Aqueous Model (WHAM): WHAM V and its improved version WHAM VI. If it is assumed that 65% of the DOC is “active”, i.e. behaving as isolated humic substances such as fulvic acid, both versions of WHAM are able to predict the labile and free-metal-ion concentrations of Ni, Zn, and Cd reasonably well; however, both underestimate the free-copper-ion concentration by one to two orders of magnitude. WHAM VI is generally better than or equal to WHAM V for successfully predicting most of the free-metal-ion concentrations. The modelled competition by Al(III) and Fe(III) in the lake surface waters showed that in most cases Cu(II) was most affected by this competition. WHAM VI predicts a larger effect from the Al(III) and Fe(III) competition than does WHAM V. 相似文献
13.
Banks CE Kruusma J Moore RR Tomcík P Peters J Davis J Komorsky-Lovrić S Compton RG 《Talanta》2005,65(2):423-429
Three different electroanalytical techniques for the detection of manganese in marine sediments are evaluated. The anodic stripping voltammetry of manganese at an in situ bismuth-film-modified boron-doped diamond electrode and cathodic stripping voltammetry at a carbon paste electrode are shown to lack the required sensitivity and reproducibility whereas cathodic stripping voltammetry at a bare boron-doped diamond electrode is shown to be reliable and selective with a limit of detection, from applying a 60 s accumulation period of 7.4 × 10−7 M and a sensitivity of 0.24 A M−1. The method was used to evaluate the manganese content of marine sediments taken from Šibenik, Croatia. 相似文献
14.
Estela de Pieri Troiani Edenir Rodrigues Pereira‐Filho Ronaldo Censi Faria 《Electroanalysis》2013,25(8):1988-1994
A simple and sensitive method for simultaneously measuring dopamine (DA), ascorbic acid (AA), and uric acid (UA) using a poly(1‐aminoanthracene) and carbon nanotubes nanocomposite electrode is presented. The experimental parameters for composite film synthesis as well as the variables related to simultaneous determination of DA, AA, and UA were optimized at the same time using fractional factorial and Doehlert designs. The use of carbon nanotubes and poly(1‐aminoanthracene) in association with a cathodic pretreatment led to three well‐defined oxidation peaks at potentials around ?0.039, 0.180 and 0.351 V (vs. Ag/AgCl) for AA, DA, and UA, respectively. Using differential pulse voltammetry, calibration curves for AA, DA, and UA were obtained over the range of 0.16–3.12×10?3 mol L?1, 3.54–136×10?6 mol L?1, and 0.76–2.92×10?3 mol L?1, with detection limits of 3.95×10?5 mol L?1, 2.90×10?7 mol L?1, and 4.22×10?5 mol L?1, respectively. The proposed method was successfully applied to determine DA, AA, and UA in biological samples with good results. 相似文献
15.
Cathodic corrosion is an enigmatic electrochemical process that etches metallic electrodes at potentials below 0 V versus the normal hydrogen electrode. Although this phenomenon was discovered in the late 1800s by Fritz Haber, it remained mostly unnoticed during the 20th century and only attracted increased attention in the past decade. This recent attention has generated marked improvements in both the fundamental knowledge and the applications of cathodic corrosion. Fundamental new insights were gained into the effects and possible reaction intermediates of cathodic corrosion. Complementing these insights, recent advances involve applications of cathodic corrosion for nanoparticle synthesis and electrocatalyst modification. Both these applied and fundamental advances will be discussed in this short review on cathodic corrosion. 相似文献
16.
A cathodic stripping voltammetry (CSV) method has been developed to determine water content in organic solvents based on electrooxidation of a gold electrode in the presence of water to form gold oxides upon anodic polarizations. Following cathodic potential scan, a sharp reductive stripping peak of gold oxides is generated and the magnitude of the peak current is related to the water content in the organic solvents. The method has been applied for determination of water in four commonly used water miscible organic solvents, acetonitrile, tetrahydrofuran, acetone and glacial acetic acid, with limits of detection of 60, 10, 40 and 10 ppm, respectively. 相似文献
17.
用混合粘合剂修饰的碳糊电极测定诺氟沙星 总被引:4,自引:0,他引:4
在pH10.50的磷酸盐缓冲溶液中 ,当含有0.8mmol/L的NH4Cl,8mg/L的SLS(十二烷基磺酸钠)时 ,诺氟沙星在由69.1% (w)的石墨粉、24.5 % (w)的液体石蜡和6.4 % (w)的甘油组成的混合粘合剂碳糊电极上产生一灵敏的阴极溶出还原峰 ,峰电位为 -1.61V ;峰电流与诺氟沙星浓度在8.0×10 -9~4.0×10 -7mol/L范围内呈良好的线性关系 ,相关系数为r=0.9949 ,检出限为3.0×10-9 mol/L ;该法用于测定诺氟沙星胶囊含量 ,结果令人满意 相似文献
18.
19.
Cathodic reduction of 2-azido-2,4-pentadien-1-ones under slightly protic conditions result in aminodienones, whereas under acetylating conditions only the methyl-N,N-diacetylaminoadienoates could be prepared in reasonable yields. The low reduction potential of the N,N-diacetylaminodienones leads to a mixture of by-products. The N,N-diacetylaminodienoates were studied as a model of the reduction of the azidodienes at higher reduction potentials. Dimerisation, reduction of the double-bonds and elimination of the N,N-diacetylamino group are possible reactions. The mechanism of reduction under acetylating conditions is discussed. 相似文献
20.
The structure of the 2-thiazolylazosalicylic acid molecule, TAS, has been determined by means of quantum SCF-CI calculations. The ionization potential and the electron affinity of TAS molecule were calculated to have the values 9.057 and 2.56 eV respectively. The solvation energies in different solvents, and the bond orders of the TAS molecule were calculated for the neutral state, the oxidized form (the cation) and the reduced form (the anion). Mixed solvent studies were carried out with TAS and 2-benzothiazolylazosalicylic acid (BTAS), using polar solvents (EtOH and MeOH) to confirm the formation of a solvent-solute complex. The azo group in the TAS molecule nas a considerable contribution in the SCFLUMO; thus cathodic reduction has been focused on the azo group and was verified experimentally by cathodic reduction. 相似文献