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排序方式: 共有2026条查询结果,搜索用时 15 毫秒
21.
Pt/钇稳定氧化锆固体电解质在高温下的电化学性质 总被引:1,自引:0,他引:1
用交流阻抗技术研究了二电极、三电极Pt/钇稳定氧化锆(简称YSZ)高温固体电化学体系.开路电位下,Pt/YSZ体系只有一个阻抗半圆,对应于电极体系的电化学活化控制过程,极化电阻随温度变化的表观活化能为171.5kJ/mol.Pt/YSZ界面的双电层电容约为300μF/cm2.阳极极化下,交流阻抗极化电阻显著减小;阴极极化下,极化电阻反而增大,并出现浓差控制现象. 相似文献
22.
用浸渍法制备了掺杂不同质量分数的La0.8Sr0.2Ga0.8Mg0.15Co0.05O3-δ (LSGMC5)粉末的Ni8-Fe2-LSGMC5复合阳极, 并采用交流阻抗和直流极化技术考察了以氢气和二甲醚为燃气时该复合阳极的电化学性能及相应电池的功率输出特性. 结果表明, 在电极中掺入LSGMC5 粉末, 能显著地改善电极的形貌和电极/电解质界面结构, 减小欧姆电阻和极化电阻. 电极中LSGMC5 粉末含量对于氢气及二甲醚电化学氧化性能的影响显著不同. 以二甲醚为燃气时, 电极极化电阻随LSGMC5 粉末含量的增加而减小, 其中LSGMC5 掺杂量为30%的复合阳极具有最高的电化学性能, 相应电池在1073、1023、973 K 时的输出功率分别为1.00、0.61、0.40 W·cm-2; 以氢气为燃气时, LSGMC5 掺杂量为20%的复合阳极具有最好的电化学性能, 随着LSGMC5 掺杂量的进一步增加, 电极极化电阻显著增大. 相似文献
23.
Ostanina T. N. Rudoi V. M. Yaroslavtseva O. V. Solov'ev A. S. Subbotina O. Yu. Dokashenko S. I. 《Russian Journal of Electrochemistry》2004,40(10):1019-1023
The impedance of zinc-rich polymer coatings on steel in a 3-% NaCl solution is studied. The electrochemical behavior of the electrode is satisfactorily described by an equivalent circuit that contains a constant-phase element, which reflects fractal properties of the zinc surface in the binder. From the results of calculations of the circuit elements for metal-rich electrodes with different zinc contents computed are fractions of the active area of the surface of the coating and its fractal dimensionality. 相似文献
24.
The electrical properties of polycrystalline lithium chloroboracite, Li4B7O12Cl, prepared by the sol-gel method were investigated in connection with their structure. Li4B7O12Cl pellets were prepared with different amounts of hydrochloric acid or ammonium chloride. The kind and amount of the chlorine source affected the formation of by-products (Li2B4O7, LiCl, a glass phase) and the morphology of the Li4B7O12Cl pellets. Thus their conductivity, which is dominated by grain boundary response owing to the high porosity of the materials, was also affected. The formation of Li2B4O7 as a by-product led to a higher activation energy and lower conductivity. In those pellets in which Li2B4O7 did form, an increase of the amount of glass phase led to higher conductivities. 相似文献
25.
Impedance biosensors are a class of electrical biosensors that show promise for point-of-care and other applications due to low cost, ease of miniaturization, and label-free operation. Unlabeled DNA and protein targets can be detected by monitoring changes in surface impedance when a target molecule binds to an immobilized probe. The affinity capture step leads to challenges shared by all label-free affinity biosensors; these challenges are discussed along with others unique to impedance readout. Various possible mechanisms for impedance change upon target binding are discussed. We critically summarize accomplishments of past label-free impedance biosensors and identify areas for future research. 相似文献
26.
Alexander S. Bondarenko Genady A. Ragoisha 《Journal of Solid State Electrochemistry》2005,9(12):845-849
Potentiodynamic electrochemical impedance spectroscopy provides extraction of potential-dependent space charge layer capacitance
from potentiodynamic impedance spectra of non-stationary semiconductor–electrolyte interface. The new technique has been applied
for acquisition of Mott-Schottky plots of cathodically treated TiO2 anodic films. Cathodic treatment in 1 M H2SO4 increases donor density and flat band potential of TiO2. Freshly doped films show hysteresis in the space charge layer capacitance in cyclic potential scans. The subsequent cycling
eliminates the hysteresis but preserves the greater part of the doping effect.
Presented at the 4th Baltic Conference on Electrochemistry, Greifswald, 13–16 March 2005 相似文献
27.
28.
BaCe1—xRExO3—0.5x的溶胶—凝胶法合成及离子导电性 总被引:3,自引:0,他引:3
用溶胶-凝胶法合成了系列钙钛矿结构的BaCe1-xRExO3-0.5x(RE=La,Nd,Sm,Eu,Gd,Dy,Ho,Er和Y)复合氧化物,通过XRD和热分析对样品结构及生成过程进行了研究.测定了不同温度下样品的交流阻抗谱,讨论了稀土离子掺杂对BaCeO3电性质的影响.溶胶-凝胶法比固相反应法合成温度降低了600~800℃,稀土掺杂使BaCeO3离子导电率提高了10~40倍. 相似文献
29.
Electrochemical behavior of poly-o-phenylenediamine (PoPhD) films in lithium perchlorate and perchloric acid solutions of different pH and constant ionic strength is studied using cyclic voltammetry, low-amplitude chronoamperometry, chronopotentiometry, and faradaic-impedance spectroscopy. The experimental results point to the diffusion–migration kinetics of charge transfer processes in redox-active PoPhD films and show that two such processes occur during oxidation–reduction of PoPhD. The processes are separated most fully at low concentrations of hydronium ions. Effect of the electrode potential and electrolyte composition on these processes is examined. Different methods yield similar results and permit their more reliable interpretation. 相似文献
30.
Joachim Franzke Maria-Antoaneta Bratescu Damir Veza Kay Niemax 《Mikrochimica acta》1994,113(3-6):349-355
Laser impedance spectroscopy in a miniature neon RF-discharge operating at 0.27 bar was performed. The dominant role of the metastable atoms to the size and the sign of the RF-signal was investigated. Excellent linearity of the RF-signal but poor detection sensitivity of excited metastable neon atoms were found at low laser powers. 相似文献