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631.
632.
An ionic liquid bulk-modified carbon paste electrode (M-CPE) has been fabricated by using 1-heptyl-3-methylimidazolium bromide as a modifier. Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) were used to evaluate the electrocatalytic activity of the proposed electrode by choosing p-aminophenol (p-AP) as a model compound. Both at a bare carbon paste electrode (CPE) and the M-CPE, p-AP yielded a pair of redox peaks in 0.1 mol·L^-1 phosphate buffer solution (PBS, pH 7.0). At the CPE, the peak-to-peak potential separation (AEp) was 0.233 V, while at the M-CPE the AEp was decreased to 0.105 V. Furthermore, the current response to p-AP at the M-CPE was 10.2 times of that at the CPE by DPV. The electron transfer rate constant (ks) ofp-AP at the M-CPE was 13.3 times of that at the CPE. Under the optimal condition, a linear dependence of the catalytic current versus p-AP concentration was obtained in the range of 2.0× 10^- 6 to 3.0× 10^- 4 mol·L^-1 with a detection limit of 6.0× 10^-7 mol·L^-1 by DPV. In addition, compared to other modified method the proposed electrode exhibited distinct advantages of simple prapartion, surface renewal, good reproducibility and good stability. It has been used to determine p-AP in simulated wastewater samples. 相似文献
633.
The interaction between adenine and beta-CD has been investigated in solution and in the solid state by several analytical techniques, primarily by 1H-NMR, 2D ROESY and fluorescence spectra, and secondarily by other important techniques, for example, Fourier transform infrared spectroscopy (FT-IR) and differential scanning calorimetry (DSC). The association constant and 1:1 nature of the complex between adenine and beta-CD in solution were determined by fluorescence spectroscopy. A spatial configuration for the complex in solution is proposed from analysis of the 1H-NMR and 2D ROESY data. The Fourier transform infrared spectroscopy (FT-IR) and differential scanning calorimetry (DSC) data are consistent with the formation of an inclusion complex. In addition, a solid inclusion complex of adenine with beta-CD was synthesized by the coprecipitation method. 相似文献
634.
用脉冲波交流电流作为极化电流的微分简易示波伏安法 总被引:7,自引:1,他引:7
用脉冲波交流电流作为极化电流的微分简易示波伏安法郑建斌,赵明仁,朱小红,苏玉祥(西北大学化学系电分析化学研究所,西安,710069)关键词示波分析,微分简易示波伏安法,脉冲波交流电流经典示波计时电位法在微量乃至于痕量组分的直接测定方面的应用一直进展缓... 相似文献
635.
636.
A study on organized assemblies in the sodium alkylcarboxylate/fatty alcohol/water systems 总被引:1,自引:0,他引:1
The phase behavior and evolution of self-organized assembling structures in the sodium alkylcarboxylate/fatty alcohol systems were investigated by TEM.With increasing concentration of fatty alcohol,the micelles transform into lamellar La phase,sponge L3 phase,multilamellar vesicle,and transfonn back to lamellar La phase.At higher alcohol concentration,a stable two aqueous phase coexisting region has been observed in this kind of systems after aged two months.Unilamellar vesicles were found both in two separated phases but the vesicle density of the upper phase is much higher than that of the bottom phase. 相似文献
637.
638.
To construct a bioactive interface between metal implant and the surrounding bone tissue, the gradient calcium phosphate bioceramic coating on titanium alloy (Ti-6Al-4V) was designed and fabricated by laser cladding. The results demonstrated that the gradient bioceramic coating was metallurgically bonded to the titanium alloy substrate. The appearance of hydroxyapatite and β-tricalcium phosphate indicated that the bioactive phases were synthesized on the surface of coating. The microhardness gradually decreased from the coating to substrate, which could help stress relaxation between coating and bone tissue. Furthermore, the methyl thiazolyl tetrazolium (MTT) assay of cell proliferation revealed that the laser-cladded bioceramic coating had more favorable osteoblast response compared with the surface of untreated titanium alloy substrate. 相似文献
639.
本文讨论局部紧半群上概率测度的组合收敛性,主要结果是利用局部群化的方法给出了概率测度组合收敛的一些结果. 相似文献
640.
经典推理模式的随机化研究及其应用(Ⅱ) 总被引:7,自引:2,他引:5
证明了D-逻辑度量空间中三种近似推理模式是等价的,指出了全体原子公式之集在D-逻辑度量空间中未必是全发散的. 相似文献