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151.
The dc and ac electrical transport property of Polyvinyl Alcohol-Multiwall Carbon Nanotubes (PVA-MWNT) composites has been investigated within a temperature range and in the frequency range 20Hz-1MHz. The temperature variation of dc conductivity gives the presence of two different activation energies. The dielectric properties of the samples have been explained in terms of electric modulus vector.The dielectric relaxation has been explained in terms of interfacial polarization occurring in between the insulating PVA matrix and MWNT conductive filler. The variation of the relaxation time with temperature also indicates the presence of two different activation energies. 相似文献
152.
153.
In this paper, an enantioselective synthesis of diplodialide-B has been described. To accomplish this target, a combination of regioselective ring opening of the chiral epoxide, Jacobsen hydrolytic kinetic resolution and Yamaguchi macrolactonization were used as the key steps. 相似文献
154.
155.
Indhumathi Kulandhaisamy Dinesh Babu Rajendran Malathi Kanagasabai Gunasekaran Gurusamy Balaji Moorthy Jithila V. George 《Waves in Random and Complex Media》2017,27(1):38-46
In this paper, an analog multiband phase shifter using slotline configuration is proposed. To implement the design, a pair of modified Split Ring Resonator (SRR) is employed. The periodic property of SRR provides multiband characteristics, whether the coupling slot gives the phase variations over the bands. The operation is well explained with an equivalent circuit model and its characteristics have been studied both in simulation and measurement. The prototype operates in 1.77–2.16, 3.5–3.97, 5.08–5.33, 6.43–6.93, and 8.01–8.59 GHz frequency bands which can be utilized for GSM, GPS, WLAN, C-band, and X-band applications, respectively. 相似文献
156.
157.
We report the observation of persistent photoconductivity (PPC) in flower shaped PbS dendrites grown by the hydrothermal method. Potential fluctuations, due to the presence of various confinement regimes in the branches of dendrites, and surface traps, are likely responsible for the PPC observed here. We also observed photocurrent quenching and decreased dark current in the PPC below 40 K, due to the presence of a metastable state, whereas positive PPC was observed in the temperature region 40–220 K. Dark conductivity measurements, time constant parameters obtained from the stretched exponential fittings of PPC, also showed the metastable state related transition around 50 K. 相似文献
158.
Chandreshwar Thakur Ram Babu Mishra 《International Journal of Theoretical Physics》1990,29(9):1029-1037
Steady flow of an inviscid, incompressible two-phase magnetofluid with infinite electrical conductivity is treated. With one ignorable coordinate in a general orthogonal curvilinear system, general solutions of the equations, considering number densityN constant throughout the motion, are obtained. 相似文献
159.
N K Porwal R M Kadam Y Babu M D Sastry M D Aggarwal Putcha Venkateswarlu 《Pramana》1997,48(4):929-935
Photo-induced charge transfer and its kinetics were investigated in Bi12SiO20 in 10–300 K temperature range, using EPR of Fe3+ centre, underin situ illumination with copper vapour laser (CVL). The decay kinetics was found to follow double exponential behaviour. Relaxation
of the photo-induced electron transfer to the preillumination condition occurred even at 10 K. Shallow traps were, therefore,
associated with the electron trapping, leading to a better understanding of the fast photorefractive response of BSO. 相似文献
160.