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241.
We demonstrate an optical technique to derive the two-dimensional energy conversion efficiency (ηCE), fill factor (FF) and external quantum efficiency (ηQE) distributions across the surface of photovoltaic devices. A compact, inexpensive optical-feedback laser diode microscope is constructed to acquire the confocal reflectance and efficiency maps enabling the observation of the local parametric behavior in silicon photodiodes in photovoltaic mode and single-junction solar cells. The ηCE and ηQE distributions are greatly influenced by local parasitic resistances that depend on laser irradiance. These parasitic resistances decrease the ηCE and ηQE values with distance from the contact electrode at high laser irradiance. The optical technique enables microscopic comparison of ηCE and ηQE within the pn-overlay region of the photodiode sample, revealing its optimization for photodetection rather than power generation. The technique also elucidates the decreasing local ηCE of the solar cell under intense irradiation. 相似文献
242.
Carlos Elvira Beln Levenfeld Blanca Vzquez Julio San Romn 《Journal of polymer science. Part A, Polymer chemistry》1996,34(13):2783-2789
Two tertiary amines with a chemical structure rather similar to dimethyl-4-toluidine have been prepared and tested as activators for the free radical polymerization of methyl methacrylate. 4-Dimethylaminobenzyl alcohol, DMOH, was synthesized by reduction of the corresponding benzaldehyde. 4-Dimethylaminobenzyl methacrylate, DMMO, was synthesized by condensation of methacryloyl chloride with DMOH in the presence of triethylamine as catalyst. Kinetic studies of the bulk polymerization of methyl methacrylate initiated by the redox system BPO–amine have been carried out by differential scanning calorimetry at different temperatures in the interval 30–40°C. An increase of the overall rate constant, k, with increasing temperature was observed for all redox systems. The system BPO/DMT gave the highest values of k. The polymerizations catalyzed by DMOH and DMMO respectively gave lower values of the overall Arrhenius activation than that obtained with DMT. DMMO may participate in the polymerization not only as activator but also as an acrylic derivative which can be incorporated into the polymeric growing chains during the propagation step of the free radical polymerization. © 1996 John Wiley & Sons, Inc. 相似文献
243.
Reinier Lemos Dr. Kamil Makowski Dr. Luis Almagro Dr. Blanca Tolón Dr. Hortensia Rodríguez Dr. M. Ángeles Herranz Dr. Dolores Molero Prof. Dr. Nazario Martín Prof. Dr. Margarita Suárez 《European journal of organic chemistry》2023,26(7):e202201301
Cyclopropanation reactions between C60 and different malonates decorated with monosaccharides and steroids using the Bingel-Hirsch methodology have allowed the obtention of a new family of hybrid compounds in good yields. A complete set of instrumental techniques has allowed us to fully characterize the hybrid derivatives and to determine the chemical structure of monocycloadducts. Besides, the proposed structures were investigated by cyclic voltammetry, which evidenced the exclusive reductive pattern of fullerene Bingel-type monoadducts. Theoretical calculations at the DFT-D3(BJ)/PBE 6-311G(d,p) level of the synthesized conjugates predict the most stable conformation and determine the factors that control the hybrid molecules′ geometry. Some parameters such as polarity, lipophilicity, polar surface area, hydrophilicity index, and solvent-accessible surface area were also estimated, predicting its potential permeability and capability as cell membrane penetrators. Additionally, a molecular docking simulation has been carried out using the main protease of SARS-CoV-2 (Mpro) as the receptor, thus paving the way to study the potential application of these hybrids in biomedicine. 相似文献