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41.
42.
Alwin S. Wheeler 《Fresenius' Journal of Analytical Chemistry》1909,48(11):712
Ohne Zusammenfassung 相似文献
43.
Solar panels and bio‐optical sensors play a significant and growing role in a number of applications that are of importance to many organizations. Many of these instruments require a high transmission of radiation into the device for it to work properly. A major issue faced is that harsh marine environments often aid in the growth or development of fouling on the coverglass used to protect the instruments. Over a period of time in an ocean environment, some plant or animal may attach itself to the coverglass, ultimately obscuring the glass and rendering the instrument useless. As such, an antifouling mechanism is needed for these instruments that is inexpensive, long‐lasting, and environment friendly. The approach discussed herein involves the use of known antifouling chemicals which have been incorporated into the polymer matrix. Polymethylmethacrylate (PMMA), bisphenol A polycarbonate (Bis A PC), and a co‐polyterephthalate (CPTE) were examined. The plaques are optically transparent and previous work has shown that, for most samples, the materials display a minimal decrease in mechanical behavior upon the addition of the algaecides. This paper will discuss the effects on the materials' optical properties when exposed to both harsh marine conditions as well as high intensity UV light. Specifically, the decrease in transmission of visible light was examined over a 6 month period of time. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
44.
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46.
Wheeler 《Fresenius' Journal of Analytical Chemistry》1866,5(1):414
Ohne Zusammenfassung 相似文献
47.
Pei-Hsun Wei Mukulesh Mondal Gero D. Harzmann Kraig A. Wheeler 《Tetrahedron letters》2010,51(51):6690-6694
The mechanism of PBu3-catalyzed homodimerization of ketoketenes has been explored and compared with that of the previously reported trialkylphosphite-mediated reactions. NMR studies of the PBu3-catalyzed reaction implicated the involvement of tetravalent phosphonium intermediates. Phosphonium intermediates in the catalytic cycle were trapped through reaction with trimethylsilyl chloride and 4-chlorobenzaldehyde, and the resulting products were characterized. A method for the stoichiometric generation of phosphonium enolates was developed as a result of these studies. No evidence was obtained for the involvement of pentacovalent phosphorane intermediates in trialkylphosphine-catalyzed ketoketene homodimerization reactions, in contrast with the mechanism of the trialkylphosphite-mediated homodimerization of dimethylketene. An X-ray crystal structure analysis of methylphenylketene dimer showed that it possesses Z-geometry about the exocyclic olefin. 相似文献
48.
Max M. Abrahams Gregory W. Cushing Zachary N. Pickett William A. Howard Kraig A. Wheeler 《Journal of chemical crystallography》2010,40(7):583-590
Abstract
Mer-RhBr3(Me2pzH)3 (Me2pzH = 3,5-dimethylpyrazole) (monoclinic, P21/n, a = 8.3300 (5) Å, b = 16.2889 (9) Å, c = 15.9299 (11) Å, α = 90°, β = 100.217 (5)°, γ = 90°; V = 2,127.2 (2) Å3; Z = 4) has been characterized by X-ray diffraction, 1H and 13C nuclear magnetic resonance spectroscopy, infrared spectroscopy, and electronic absorption spectroscopy, and modeled by density functional theory (DFT) and time-dependent density functional theory (TDDFT). Mer-RhBr3(Me2pzH)3 is an octahedral complex with a HOMO → LUMO transition at 486 nm. The DFT and TDDFT calculations predicted mer-RhBr3(Me2pzH)3 to be an octahedral complex with a HOMO → LUMO transition at 540 nm. 相似文献49.
L.Q. EnglishS.G. Wheeler Y. ShenG.P. Veldes N. WhitakerP.G. Kevrekidis D.J. Frantzeskakis 《Physics letters. A》2011,375(9):1242-1248
We study experimentally, analytically and numerically the backward-wave propagation, and formation of discrete bright and dark solitons in a nonlinear electrical lattice. We observe experimentally that a focusing (defocusing) effect occurs above (below) a certain carrier frequency threshold, and backward-propagating bright (dark) discrete solitons are formed. We develop a discrete model emulating the relevant circuit and benchmark its linear properties against the experimental dispersion relation. Using a perturbation method, we derive a nonlinear Schrödinger equation, that predicts accurately the carrier frequency threshold. Finally, we use numerical simulations to corroborate our findings and monitor the space-time evolution of the discrete solitons. 相似文献
50.
A. J. Wheeler 《Fresenius' Journal of Analytical Chemistry》1908,47(2-3):174
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