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991.
Z. Gruba? 《Materials Letters》2007,61(3):794-798
The initial stage of copper electrodeposition on the electrochemically activated assembly of carbon microelectrodes from an acid solution of copper sulfate was investigated using cyclic voltammetry, potentiostatic pulse technique and electrochemical impedance spectroscopy. Analysis of the experimental current transients has been carried out using a non-linear fitting procedure according to the model that takes into account spherical diffusion towards a disc-shaped microelectrode. The higher values of diffusion coefficient in comparison with those observed on planar electrodes were explained with an increased diffusion caused by the electrode geometry. Impedance spectra showed two time constants, the high-frequency related to the charge transfer process and the low-frequency corresponded to the deposit morphology. 相似文献
992.
A. D. Bulanov P. G. Sennikov V. A. Krylov T. G. Sorochkina L. A. Chuprov O. Yu. Chernova O. Yu. Troshin 《Inorganic Materials》2007,43(4):364-368
Using gas chromatography and high-resolution Fourier-transform IR spectroscopy, we have determined the concentrations of C1–C4 hydrocarbon impurities in isotopically unmodified silicon tetrafluoride before and after fine purification and in 28Si-enriched SiF4. The concentrations of C1–C4 hydrocarbon impurities in silicon tetrafluoride for SiH4 synthesis have been shown to correlate with those in the synthesized silane. 相似文献
993.
D. L. Kuznetsov E. V. Kol’man Yu. S. Surkov V. V. Uvarin I. E. Filatov 《Technical Physics Letters》2007,33(7):604-606
The process of methane conversion in a mixture modeling the natural gas under the action of a periodic nanosecond pulsed electron beam and an electron-beam-induced non-self-sustained discharge has been numerically simulated and studied in experiment. The possibility of methane conversion under the action of electric pulses without significant heating of the processed gas mixture is demonstrated for the first time. The main conversion products in experiment were hydrogen, ethylene, and acetylene. 相似文献
994.
Capacitor voltage balancing in multilevel flying capacitor inverters by rule-based switching pattern selection 总被引:1,自引:0,他引:1
A rule-based scheme is investigated for capacitor voltage balancing in a multilevel flying capacitor inverter (MFCI). Without using voltage feedback, the scheme determines the best switching pattern for maintaining nil mean current in all capacitors, hence minimising the capacitor voltage fluctuation. The method is developed to work with the selective harmonic elimination (SHE) technique for sinusoidal voltage generation applied to control static VAR compensators. The method has been designed using a four-cell five-level MFCI as an example. The selected pattern has been shown to give superior performance in load-voltage total-harmonies distortion level and mean capacitor voltage fluctuation. The method is validated experimentally for this form of MFCI 相似文献
995.
This article describes the application, at the team and individual level, of findings from the positive psychology research. An overview of this research is presented focusing on several areas generally included in the positive psychology domain: flow, appreciative inquiry, the broaden and build theory, and other strategies for increasing the experience of positive emotions and the identification and deployment of strengths. The authors propose that these applications show promise in consulting psychology engagements and may have merit when utilized by practitioners themselves. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
996.
997.
V. A. Sychevskii N. V. Pavlyukevich L. L. Vasil'ev S. Rozin 《Journal of Engineering Physics and Thermophysics》2003,76(1):18-27
A problem of the Stefan type which describes heat and mass transfer in a porous body with the double phase transition liquid–ice–vapor has been formulated and solved. 相似文献
998.
999.
Two-photon pumping of a random laser 总被引:1,自引:0,他引:1
Burin A.L. Hui Cao Ratner M.A. 《IEEE journal of selected topics in quantum electronics》2003,9(1):124-127
Random lasing originates from pumping disordered materials by high-intensity and high-frequency light. The performance of random lasers is restricted due to the absorption of pumping light within the interfacial layer. The lifetime of optical modes there is short due to the emission of photons to the outside, and it is hard to pump them sufficiently for lasing. The opportunity to excite the modes far from the material surface using two-photon absorption is investigated within the diffusion model. The authors show that lasing requires lower pump power for the two-photon pumping mechanism under conditions of negligible absorption of the emitted light. Experimental implications and restrictions are discussed. 相似文献
1000.