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991.
I. N. Justinijanović J. N. Jovićević A. R. Despić 《Journal of Applied Electrochemistry》1973,3(3):193-200
Kinetic and morphological studies have been made of the deposition of zinc powder on steel substrate, from pure alkaline zincate electrolytes and with small amounts of lead and tin ions in the electrolyte. The rate of co-deposition of hydrogen has been followed volumetrically and the current efficiency of zinc deposition calculated as a function of potential.The addition of lead and tin was found to have a profound effect on the properties of the powder. The dendritic powder, obtained from pure zincate solutions, changes with the addition of lead into a mossy deposit consisting of very small crystallites. Both additives increase the specific surface area of the powder and the average lattice parameters. Hydrogen evolution per unit real surface area and hence the corrosion of the powder are somewhat inhibited by both additives.Reported at the Symposium on Electrocrystallization, 140th Meeting of the Electrochemical Society, Cleveland, Ohio, October 1971. 相似文献
992.
993.
994.
995.
Pulsating potential electrolysis has been applied to one typical electrocatalytic reaction ie, the oxidation of formic acid on platinum and platinum partially covered by lead adatoms electrodes. It has been found that much higher average cds can be obtained with such regimes than in constant potential electrolysis. The effect can be of considerable interest for the application in electrochemical power sources. An analysis of the mechanism of effects of pulsating potentials has been given. A calculated frequency dependence of the average current density is in agreement with experimental one for both electrodes. 相似文献
996.
The second discharge step of nickel oxide accumulator electrodes is suppressed in the presence of a Teflon binder and/or cobalt, cerium, or manganese hydroxide, whereas the first discharge step increases. This behaviour is discussed in terms of ohmic resistance effects and semiconducting properties of the active material. 相似文献
997.
Predictions of size distributions, mean sizes and coefficients of variation in mixed-suspension mixed-product removal crystallizers are presented for the case when crystal growth rate is given by the expression G = G0 (1 + γL)b as suggested by Abegg, Stevens and Larson (ASL). Crystal size distributions were measured at three scales of operation (1, 5 and 30 1.) for a system which exhibits size-dependent growth (potash alum/water). Experimental median sizes were in good agreement with the predictions and coefficients of variation significantly greater than 50% were obtained. The observed variation of crystal growth rate with size however was only moderately well represented by the ASL equation. 相似文献
998.
Übersicht Zunächst werden Formeln für den Motorstrom in Zusammenhang mit der Einphasen-Ausgleichswelle gegeben; weiter wird gezeigt, wie die Motor-Arbeitsdiagramme konstruiert werden können, d. h. entweder mit Hilfe der berechneten Parameter oder mit Hilfe der durch Experimente erhaltenen Angaben.Mit 10 Textabbildungen. 相似文献
999.
1000.
U. V. Desnica B. Šantić Dunja I. Desnica M. Pavlović 《Journal of Electronic Materials》1993,22(4):403-407
Trapping and recombination of free carriers by deep level T3 has been studied. Occupancy of the level by electrons and dynamics of its filling and emptying as a function of illumination
with monoenergetic photons in 0.69–1.55 eV range has been monitored by the thermally stimulated currents method. We have found
that level T3 behaves more like a recombination center than like an ordinary electron trap. Besides trapping free electrons from conduction
band, this trap can also communicate with valence band, trapping holes. The capture cross section for trapping a hole is estimated
to be comparable or even larger than the capture cross section for trapping an electron. However, in many experimental conditions
free electrons are generated more abundantly than free holes, and free carrier mobility and thermal velocity are both much
higher for electrons than for holes. Therefore, electron trapping often prevails, so that this frequently detected defect,
has been up to now most often perceived as a deep electron trap. 相似文献