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Hrabovsky M. Konrad M. Kopecky V. Sember V. 《IEEE transactions on plasma science. IEEE Nuclear and Plasma Sciences Society》1997,25(5):833-839
Experimental investigation of an electric arc stabilized by a water vortex was carried out in a DC arc plasma torch for the power range 90-200 kW. Volt-ampere characteristics of the arc as well as the power balance were determined separately for the part of the arc column stabilized by water and for the remaining part between the nozzle exit and the external anode. The temperature of arc plasma close to the nozzle exit was determined by emission spectroscopy. Negatively biased electric probes in the ion collecting regime were used for determination of the plasma flow velocity. The measured temperatures up to 27000 K, and velocities up to 7 km/s are higher than the values commonly reported for plasma torches with DC arcs stabilized by a gas flow. Mass and energy balances within the arc chamber were determined from the experimental results. The radial transport of the energy by radiation was identified as a decisive process controlling the arc and plasma properties. The balance of radial energy transport was studied. The ratio of energy spent for evaporation of the water to the energy absorbed in the evaporated mass is very low in the water stabilized arc. This is the principal cause of high plasma temperatures and velocities found by the measurements 相似文献
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A new bioinspired nanomaterial has been obtained by chemisorption of folic acid onto nanocrystalline titanium dioxide. The organic chromophore is linked with the semiconductor surface via the glutamate chain and anchored with the carboxylate group. The geometry and electronic structure of the chromophore was studied in detail with DFT. Photoelectrochemical studies revealed photosensitization of the new material towards visible light. The photoelectrodes composed of the folic acid/titanium dioxide hybrid material generated photocurrent over a 300–600‐nm window. Moreover, the direction of the photocurrent could be changed from anodic to cathodic and vice versa by application of the appropriate photoelectrode potential. Photoelectrochemical and spectroscopic studies allowed the elucidation of the mechanism of photocurrent switching. Photoelectrodes composed of folate‐modified titanium dioxide may serve as a simple model of optoelectronic switches and may constitute the basis for molecular photoelectronic devices. 相似文献
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Ohne ZusammenfassungHerrn Prof. Dr.A. Zinke zur Vollendung des 70. Lebensjahres gewidmet. 相似文献
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