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Ali Akbar Moshfegh Behnaz Mazandarani Azarmidokht Nahid Gholam Hosein Hakimelahi 《Helvetica chimica acta》1982,65(4):1229-1232
A short synthesis of the title compounds is reported. Most of the compounds prepared were found to be active against a number of pathogenic microorganisms in vitro. 相似文献
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Ehsan Moaseri Majid Karimi Behnaz Bazubandi Majid Baniadam Morteza Maghrebi 《Polymer Science Series A》2017,59(5):726-733
Alignment of multi-walled carbon nanotubes (MWCNTs) in a bulk epoxy matrix was studied using a magnetic-assisted method. In this study, the applicability of solenoid magnetic field was compared to that of static magnetic field, which has recently been published. It has been found that solenoid magnetic field is able to provide better alignment of MWCNTs due to the uniform magnetic field along the axis of solenoid. Remarkable improvements were achieved in the mechanical properties of aligned MWCNT-reinforced epoxy composites. Alignment of MWCNTs was clearly observed in all regions of the composites by scanning electron microscopy and transmission electron microscopy. 相似文献
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We report extensive simulations of the relaxation dynamics of a self-avoiding polymer confined inside a cylindrical pore. In particular, we concentrate on examining how confinement influences the scaling behavior of the global relaxation time of the chain, tau, with the chain length N and pore diameter D. An earlier scaling analysis based on the de Gennes blob picture led to tau approximately N(2)D(13). Our numerical effort that combines molecular dynamics and Monte Carlo simulations, however, consistently produces different tau results for N up to 2000. We argue that the previous scaling prediction is only asymptotically valid in the limit N"D(53)"1, which is currently inaccessible to computer simulations and, more interestingly, is also difficult to reach in experiments. Our results are thus relevant for the interpretation of recent experiments with DNA in nano- and microchannels. 相似文献
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Seyedeh Behnaz Varandili Dragos Stoian Jan Vavra Kevin Rossi James R. Pankhurst Yannick T. Guntern Núria Lpez Raffaella Buonsanti 《Chemical science》2021,12(43):14484
Understanding the catalyst compositional and structural features that control selectivity is of uttermost importance to target desired products in chemical reactions. In this joint experimental–computational work, we leverage tailored Cu/ZnO precatalysts as a material platform to identify the intrinsic features of methane-producing and ethanol-producing CuZn catalysts in the electrochemical CO2 reduction reaction (CO2RR). Specifically, we find that Cu@ZnO nanocrystals, where a central Cu domain is decorated with ZnO domains, and ZnO@Cu nanocrystals, where a central ZnO domain is decorated with Cu domains, evolve into Cu@CuZn core@shell catalysts that are selective for methane (∼52%) and ethanol (∼39%), respectively. Operando X-ray absorption spectroscopy and various microscopy methods evidence that a higher degree of surface alloying along with a higher concentration of metallic Zn improve the ethanol selectivity. Density functional theory explains that the combination of electronic and tandem effects accounts for such selectivity. These findings mark a step ahead towards understanding structure–property relationships in bimetallic catalysts for the CO2RR and their rational tuning to increase selectivity towards target products, especially alcohols.A higher degree of surface alloying and Zn concentration boosts the selectivity towards ethanol of CuZn catalysts in CO2 electroreduction. 相似文献
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A novel Cu–Zn β‐cyclodextrin (CuZn/β‐CD) model compound was synthesized under ultrasound irradiation to mimic the functionality of copper zinc superoxide dismutase (CuZnSOD). For comparison, Cu/β‐CD and Zn/β‐CD complexes were also synthesized via a sonochemical approach. The obtained complexes were characterized by FTIR, ICP‐OES, UV–vis and Scanning electron microscopy‐Energy dispersive X‐ray (SEM‐EDX) techniques. The SOD activity of the complexes was evaluated by a pyrogallol autoxidation method. These enzyme‐mimetic materials scavenge ambient free radicals, with the potential to provide significant antioxidant protection (scavenging ability > 70%). 相似文献
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Mahdi Sajadieh Mohammad Dakhilalian Hamid Mala Behnaz Omoomi 《Designs, Codes and Cryptography》2012,64(3):287-308
Due to their remarkable application in many branches of applied mathematics such as combinatorics, coding theory, and cryptography, Vandermonde matrices have received a great amount of attention. Maximum distance separable (MDS) codes introduce MDS matrices which not only have applications in coding theory but also are of great importance in the design of block ciphers. Lacan and Fimes introduce a method for the construction of an MDS matrix from two Vandermonde matrices in the finite field. In this paper, we first suggest a method that makes an involutory MDS matrix from the Vandermonde matrices. Then we propose another method for the construction of 2 n × 2 n Hadamard MDS matrices in the finite field GF(2 q ). In addition to introducing this method, we present a direct method for the inversion of a special class of 2 n ?× 2 n Vandermonde matrices. 相似文献
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The incompressible flow of a Newtonian fluid over a backward-facing step is investigated numerically. The geometry is an annular pipe in which the radius of the inner cylinder decreases suddenly. Keeping the radial expansion ratio fixed axisymmetric flows are computed for outlet radius ratios from 0.1 to 1 (ratio of the inner to the outer outlet radius). The Reynolds number at which the flow separates from the outer cylinder decreases as the outlet radius ratio decreases for constant inlet geometry. The growth with Reynolds number of the recirculation zone on the inner outlet cylinder just behind the step is strongly reduced when the recirculation zone on the outer cylinder is established. (© 2015 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献