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911.
Anne E. V. Gorden† Julian Davis Vladimir Král D. Webster Keogh‡ Norman L. Schroeder 《Supramolecular chemistry》2013,25(2):91-100
The addition of aqueous pH 7 solutions of 7.2×10-3?M pertechnetate to dilute aqueous 2.5% MeOH solutions containing a water-solubilized sapphyrin, 3,12,13,22-tetraethyl-8,17-bis[bis(hydroxyethyl)-amino)carbonylethyl]-2,7,18,23-tetramethylsapphyrin (1), gives rise to spectroscopic changes in the UV–Vis spectrum of 1 that are consistent with anion-binding and sapphyrin deaggregation. The spectroscopic changes induced by pertechnetate were found to differ dramatically from those induced by the addition of either pure water or dilute nitric acid; however, they were found to parallel those seen when sodium phosphate was added to solutions of 1 under analogous experimental conditions. Fits of the spectroscopic titration data to a 1:1 binding profile revealed that the effective K describing the interaction of pertechnetate anion with 1 was ca. 3900±300?M-1; this value compares to the effective K of 23000±3000?M-1 that describes the corresponding interaction of sodium phosphate with 1. 相似文献
912.
Haibin Lu Zheming Wang Mohammed Shabab Julian Oeljeklaus Steven H. Verhelst Farnusch Kaschani Markus Kaiser Matthew Bogyo Renier A.L. van der Hoorn 《Chemistry & biology》2013,20(2):168-176
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913.
Joanna M. Krawczyk Ginka H. Völler Bartlomiej Krawczyk Julian Kretz Mark Brönstrup Roderich D. Süssmuth 《Chemistry & biology》2013,20(1):111-122
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914.
The purpose of this work is the phase-field modeling of fcc-to-bcc martensitic phase transformations in polycrystals and the coupling with crystal plasticity. Assuming microscopic periodic fields, Green-function- and fast Fourier transform (FFT)-methods are used to solve the quasi-static balance of linear momentum. The Allen-Cahn evolution equation is discretized based on a semi-implicit time integration scheme in Fourier space. Two-dimensional results are presented and the interplay between martensitic phase transformation and plastic slip is studied at different stages of the deformation. (© 2015 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
915.
We propose a nonlocal continuum model to describe the size-dependent superelastic effect observed in recent experiments of single crystal Cu-Al-Ni shape memory alloys. The model introduces two length scales, one in the free energy and one in the dissipation, which account for the size-dependent hardening and dissipation in the loading and unloading response of micro- and nanopillars subject to compression tests. The information provided by the model suggests that the size dependence observed in the dissipation is likely to be associated with a nonuniform evolution of the distribution of the austenitic and martensitic phases during the loading cycle. 相似文献
916.
Abdelhak Belaidi Thomas Dittrich David Kieven Julian Tornow Klaus Schwarzburg Martha Lux‐Steiner 《固体物理学:研究快报》2008,2(4):172-174
The local absorber layer thickness (dlocal) of solar cells with extremely thin absorber was changed between 10 nm and 70 nm. As a model system, ZnO nanorod arrays (electron conductor) with fixed internal surface area coated with In2S3 (absorber) and impregnated with CuSCN (transparent hole conductor) were applied. The performance of the small area solar cells depended critically on dlocal. The highest short circuit current density was reached for the lowest dlocal. In contrast, the highest open circuit voltage was obtained for the highest dlocal. A maximum energy conversion efficiency of 3.4% at AM1.5 was achieved. Limiting factors are discussed.(© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
917.
Julian Gebauer 《Tetrahedron letters》2005,46(1):43-46
A diastereoselective synthesis of substituted mono- and bicyclic-piperidine and pyrrolidine derivatives is presented, employing a highly selective cross metathesis (CM) reaction followed by a domino reduction-cyclization process. 相似文献
918.
919.
Julian Edward 《Mathematical Methods in the Applied Sciences》2004,27(1):91-99
The Laplace operator is considered for waveguides perturbed by a periodic structure consisting of N congruent obstacles spanning the waveguide. Neumann boundary conditions are imposed on the periodic structure, and either Neumann or Dirichlet conditions on the guide walls. It is proven that there are at least N (resp. N‐1) trapped modes in the Neumann case (resp. Dirichlet case) under fairly general hypotheses, including the special case where the obstacles consist of line segments placed parallel to the waveguide walls. Copyright © 2004 John Wiley & Sons, Ltd. 相似文献
920.