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211.
Wireless Personal Communications - Thyroid disorder affects the regulation of various metabolic processes throughout the human body. Structural and functional disorders can affect the body and the... 相似文献
212.
213.
Manish?TaunkEmail author Atul?Kapil Subhash?ChandEmail author 《Journal of Materials Science: Materials in Electronics》2011,22(2):136-142
Polypyrrole (PPy) is polymerized by chemical oxidative polymerization in presence of anionic surfactant sodium bis (2-ethylhexyl) sulfosuccinate
(DEHS) as the dopant. The electrical conductivity was optimized in terms of oxidant to monomer molar ratio and polymerization yield
was measured for these reactions. We have used ammonium persulphate (APS) as the oxidant for polymerization in this series of experiments. The effect of concentration of oxidant on the electrical
conductivity is examined. Chemical synthesis of polypyrrole is supported by FTIR spectrum. The electrical conductivity of
doped and undoped polypyrrole has been measured in the temperature range of 10–300 K and is found to increase with rise in
temperature. Electrical conductivity of PPy was analyzed in the light of various charge transport models. Analysis of the electrical conductivity data reveals that in
the temperature range 60–300 K electrical transport is predominantly governed by power law behaviour given by Kivelson model.
However in the low temperature range 10–60 K electrical transport is dominated by the fluctuation assisted mechanism. 相似文献
214.
This paper reports about the analysis and optimization of micro-geometry parameters (i.e. total profile deviation ‘Fa’ and accumulated pitch deviation ‘Fp’) of the wire electric discharge machined (WEDMed) fine-pitch miniature spur gears made of brass. Effects of four WEDM process parameters namely voltage, pulse-on time, pulse-off time and wire feed rate on the micro-geometry of the miniature gears were analyzed by conducting the experiments designed using Box–Behnken approach of response surface methodology (RSM). Analysis of variance study found all four input parameters significant. Larger deviations in profile and pitch were observed with higher values of the voltage and pulse-on time, and with lower values of wire feed rate and pulse-off time. Multi-performance optimization of WEDM parameters was done using the desirability analysis to minimize profile deviation and pitch deviation simultaneously. The values of Fa and Fp of the gear obtained by the confirmation experiment conducted at the optimized WEDM parameters were as 11.5 μm and 9.1 μm respectively. These values categorize the WEDMed gear having DIN quality number as 7 and 5 respectively for profile and pitch which are better than those obtained by the conventional miniature gear manufacturing processes. 相似文献
215.
We theoretically analyze all-optical switching in the recently characterized LOV2 domain from Avena sativa (oat) phot1 phototropin, a blue-light plant photoreceptor, based on nonlinear intensity-induced excited-state absorption. The transmission of a cw probe laser beam at 660 nm corresponding to the peak absorption of the first excited L-state, through the LOV2 sample, is switched by a pulsed pump laser beam at 442 nm that corresponds to the maximum initial D state absorption. The switching characteristics have been analyzed using the rate equation approach, considering all the three intermediate states and transitions in the LOV2 photocycle. It is shown that for a given pump pulse intensity, there is an optimum pump pulsewidth for which the switching contrast is maximum. It is shown that the probe laser beam can be completely switched off (100% modulation) by the pump laser beam at 50 kW/cm2 for a concentration of 1 mM with sample thickness of 5.5 mm. The switching characteristics are sensitive to various parameters such as concentration, rate constant of L-state, peak pump intensity and pump pulse width. At typical values, the switch-off and switch-on time is 1.6 and 22.3 mus, respectively. The switching characteristics have also been used to design all-optical not and the universal nor and nand logic gates 相似文献