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Malik Abdul Waseem ShireenAnjali Srivastava Arjita SrivastavaRahila I.R. Siddiqui 《Tetrahedron letters》2014
Reusable [bmIm]OH was found to be a highly efficient renewable homogenous catalyst for the rapid and convenient synthesis of benzoxazine-4-one derivatives from o-iodobenzoic-acid and benzonitrile at 75 °C in moderate to good yields. This methodology provides a facile and straightforward path to construct other related heterocycles in an eco-compatible fashion. 相似文献
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This paper studies the fabrication and characterization of 80 nm zinc oxide anti-reflective coating (ARC) on flexible 1.3 μm thin film microcrystalline silicon (μc-Si) solar cell. High resolution X-ray diffraction (HR-XRD) shows a c-axis oriented ZnO (0 0 2) peak (hexagonal crystal structure) at 34.3° with full width at half maximum (FWHM) of 0.3936°. Atomic force microscope (AFM) measures high surface roughness root-mean-square (RMS) of the layer (50.76 nm) which suggests scattering of the incident light at the front surface of the solar cell. UV–vis spectrophotometer illustrates that ZnO ARC has optical transmittance of more than 80% in the visible and infra-red (IR) regions and corresponds to band gap (Eg) of 3.3 eV as derived from Tauc equation. Inclusion of ZnO ARC successfully suppresses surface reflectance from the cell to 2% (at 600 nm) due to refractive index grading between the Si and the ZnO besides quarter-wavelength (λ/4) destructive interference effect. The reduced reflectance and effective scattering effect of the incident light at the front side of the cell are believed to be the reasons why short-circuit current (Isc) and efficiency (η) of the cell improve. 相似文献
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Composites of polyaniline with yttrium oxide (Y2O3) nanoparticles have been prepared by chemical polymerizations method by increasing the weight percentage of yttrium oxide. X-Ray diffraction (XRD) and Fourier Transform Infrared Spectra (FTIR) were used to characterize the composites. XRD and FTIR pattern indicate that Polyaniline (PANI) is intercalated into the layers of Y2O3 nanoparticles successfully by in situ polymerization and therefore the degree of crystallinity increases due to crystalline of yttrium oxide nanoparticles. The scanning electron micrographs (SEM) also confirm the formation of dual phase of platelet as well as of flaky structure in PANI-Y2O3. Temperature dependant DC conductivity showed three dimensional variable ranges hopping (3D VRH) model. Activation energy, density of states and hopping length are calculated and found to be influenced by intercalating PANI into the layers of Y2O3 clay. 相似文献
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Hasan M. El Ghanem Saa’Di Abdul Jawad Yazan A. Hussain Adnan S. Abu-Surrah 《Journal of Macromolecular Science: Physics》2014,53(5):878-892
Impedance spectroscopy was utilized to investigate the dielectric properties, ac conductivity and charge transport mechanisms in propylene-alt-CO/ethylene-alt-CO (EPEC) random terpolymer filled with multi-walled carbon nanotubes (MWCNT) as a function of nanofiller content, frequency, and temperature. Equivalent resistor-capacitor (RC) circuit models were proposed to describe the impedance characteristics of the unfilled terpolymer and the nanocomposite at different temperatures. For the nanocomposites, the ac conductivity tended to be frequency independent at low frequencies. At high frequencies, the ac conductivity increased with frequency. The dc conductivity (i.e., plateau of the ac conductivity at low frequencies) at room temperature increased from 10?9 (Ω·m)?1 for the unfilled polymer to l0?3 (Ω·m)?1 for the 6 wt% MWCNT/EPEC nanocomposite. At low temperatures, the equivalent RC model for EPEC-0 and EPEC-2 was found to consist of a parallel RC circuit. However, for 6 wt% MWCNT/EPEC nanocomposite, an RC model consisting of an R/constant phase element (CPE) circuit and a resistor in series was required to describe the impedance behavior of the nanocomposite. 相似文献
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Togapur Pavan Kumar Mohammad Abdul Sattar Vanka Uma Maheshwara Sarma 《Tetrahedron: Asymmetry》2013,24(24):1615-1619
An efficient protocol for the enantioselective Michael additions of ketones to chalcones catalyzed by a hydroxyphthalimide linked triazole–pyrrolidine derivative has been developed. The corresponding products, 1,5-dicarbonyl compounds, were obtained in good yields with high levels of stereoselectivities under mild reaction conditions employing benzoic acid as an additive. 相似文献