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151.
The indirect magnetic interaction in semiconductors is used to evaluate the exchange parameters for EuO and EuS respectively which yields Jeff(EuO)?(0.06 ± 0.02) eV and Jeff(EuS)?(0.08 ± 0.04) eV. 相似文献
152.
153.
Lara Jabbour Roberta Bongiovanni Didier Chaussy Claudio Gerbaldi Davide Beneventi 《Cellulose (London, England)》2013,20(4):1523-1545
Li-ion batteries (LIBs) are the most employed power source in portable electronics (e.g., cellular phones, laptop computers…) and are accounted as very promising storage/power systems for future electric/hybrid-electric powered transportation. However for their future development, low production costs and environmental friendliness will be key parameters. In this context, the introduction of water processable biosourced polymers such as cellulose and its derivatives is very interesting and is emerging as a viable route toward the development of green materials and processes for LIB manufacturing. The present review briefly introduces the Li-ion technology and gives an overview on cellulose and cellulose derivatives for the elaboration of separators, electrolytes and electrodes. 相似文献
154.
Dr. Lara Mata Prof. Alberto Avenoza Dr. Jesús H. Busto Prof. Jesús M. Peregrina 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(21):6831-6839
Although 1,2‐cyclic sulfamidates derived from α‐methylisoserine undergo nucleophilic displacement at the quaternary center, to the best of our knowledge their behavior with amines as nucleophiles has never been explored. We have found that a broad range of amines can be used, demonstrating the scope of the reaction, and that excellent control of the chemoselectivity can be achieved. Application of this methodology for the synthesis of a chiral α,β‐diamino acid and an important piperazinone heterocycle is also presented. Additionally, we have found that DMF and DMSO behave not only as polar aprotic solvents but also as O‐nucleophilic reagents, allowing the incorporation of an oxygen atom at a quaternary center of the electrophile, with inversion of configuration. 相似文献
155.
Journal of Global Optimization - We introduce and investigate a new generalized convexity notion for functions called prox-convexity. The proximity operator of such a function is single-valued and... 相似文献
156.
Blanca Ivonne Vergara-Arenas Leticia Lomas-Romero Deyanira Ángeles-Beltrán Guillermo Enrique Negrón-Silva Atilano Gutiérrez-Carrillo Víctor Hugo Lara José Antonio Morales-Serna 《Tetrahedron letters》2017,58(28):2690-2694
The acid properties of Al-MCM-41 and sulfated zirconia were used to develop a strategy for the synthesis of 4-aryl-NH-1,2,3-triazoles via a multicomponent reaction involving various benzaldehydes, sodium azide and nitromethane. The efficiency of the process is analysed from the perspective of the difference in acids among the catalysts used. 相似文献
157.
158.
The Influence of Substituent Orientation on the Photovoltaic Performance of Phthalocyanine‐Sensitized Solar Cells
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Lara Tejerina Dr. M. Victoria Martínez‐Díaz Prof. Dr. Mohammad Khaja Nazeeruddin Prof. Tomas Torres 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(13):4369-4373
Phthalocyanines (Pcs) are used as sensitizers in dye‐sensitized solar cells (DSSCs) because of their stability and intense absorption in the red and near‐IR regions. Impressive progress has been made in photovoltaic efficiencies by introduction of bulky peripheral substituents to help suppress macrocycle aggregation. To reach benchmark efficiencies reported for other related dyes, new designs need to be explored. Single carboxy‐ZnPc regioisomers substituted at the non‐peripheral positions by rigid aryl groups have now been studied, which has shed light on the influence of steric hindrance and/or orientation of the substituent around the anchoring group on the photovoltaic response. The regioisomer bearing the aryl group far away from the anchoring group produces a more effective sensitization of the TiO2 films and higher short‐circuit photocurrent density (Jsc). Taking advantage of the good photovoltaic performance in the near‐IR region of this ZnPc, it was combined with another appropriate dye for panchromatic sensitization of the mesoporous photoelectrode and an increase of the overall device efficiency. 相似文献
159.
Boundary layer flows are ubiquitous in the environment, but their study is often complicated by their thinness, geometric irregularity and boundary porosity. In this paper, we present an approach to making laboratory-based particle image velocimetry (PIV) measurements in these complex flow environments. Clear polycarbonate spheres were used to model a porous and rough bed. The strong curvature of the spheres results in a diffuse volume illuminated region instead of the more traditional finite and thin light sheet illuminated region, resulting in the imaging of both in-focus and significantly out-of-focus particles. Results of a traditional cross-correlation-based PIV-type analysis of these images demonstrate that the mean and turbulent features of an oscillatory boundary layer driven by a free-surface wave over an irregular-shaped porous bed can be robustly measured. Measurements of the mean flow, turbulent intensities, viscous and turbulent stresses are presented and discussed. Velocity spectra have been calculated showing an inertial subrange confirming that the PIV analysis is sufficiently robust to extract turbulence. The presented technique is particularly well suited for the study of highly dynamic free-surface flows that prevent the delivery of the light sheet from above the bed, such as swash flows. 相似文献
160.
Lara Perrin Ali Nourdine Emilie Planes Christian Carrot Nicole Alberola Lionel Flandin 《Journal of Polymer Science.Polymer Physics》2013,51(4):291-302
To develop n-type processable polymeric materials for photovoltaic applications, a series of polymers was synthesized by grafting fullerene C60 onto polystyrene (PS). Grafted polymers were studied and compared with PS:fullerene blends. Electronical and electrical properties were first measured to define the minimal amount of C60 required for solar cells application. Then, thermal properties and rheological behavior of grafted polymers were analyzed to determine whether they could be processed from the melt. A throughout experimental study revealed that C60-grafted polymers exhibit two thresholds. The first threshold at 3–4 vol % (detected by electrical conductivity, electron mobility, and melt viscosity measurements) is associated to the percolation of C60 molecules. The second threshold (evidenced by glass transition and melt viscosity measurements and confirmed by optical and atomic force micrograph observations) at about 12–13 vol % is assumed to be related to the formation of C60 aggregates. © 2012 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2013 相似文献