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21.
Roe C Moragas Solá T Sasraku-Neequaye L Hobbs H Churcher I MacPherson D Stockman RA 《Chemical communications (Cambridge, England)》2011,47(26):7491-7493
The synthetic utility of S-mesitylsulfinimines for the synthesis of chiral amines and aziridines was examined through their reactions with Grignard reagents, with the ylides derived from trimethylsulfonium iodide and S-allyl-tetrahydrothiophenium bromide and through an aza-Darzens manifold, affording convenient access to a diverse range of highly substituted chiral amines and aziridines in high yields and excellent stereoselectivities. 相似文献
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For the 2006 ASA Data Exposition we created graphics that, in the legacy of John Tukey, tried to “force the unexpected upon us” (Tukey in Proceedings of the 18th conference on design of experiments in Army research and development I, Washington, 1972). The data were geographic and meteorological measurements taken every month for 6 years on a coarse 24 by 24 grid covering Central America. Using conventional static graphics and some less conventional interactive graphics, we were able to find expected features in the data, such as seasonal patterns, spatial correlations, and El Niño events, as well as some more surprising results, several of which were corroborated by stories in the news. 相似文献
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The effects of radiation-induced solute redistribution and diffusion are studied for 30 keV Mn implants in nickel irradiated with 75 keV Ni+ ions at 500°C. The peak of the Mn implant profile is driven to greater depth with increasing irradiation dose until a steady-state solute profile is established. The rate of drift of Mn atoms and their diffusion coefficient is related to the distribution of point-defects in the nickel under irradiation. 相似文献
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The VideoAFM provides a 1000 fold increase in image rate compared to conventional atomic force microscopes, giving nanometre resolution images of surfaces at a rate of 15 frames s(-1), which is approximately 1 million pixels s(-1). Images of high stiffness surfaces such as calibration grids are provided for the first time, and allow for a more rigorous examination of the meaning of the data obtained with the VideoAFM. Instrumental changes that could provide true topographic images are discussed. The advantages of a high speed scanning technique that is integrated within a conventional AFM are outlined. Particular emphasis is given to the capability to 'tile' images, and hence rapidly map large areas with nanometre resolution. It is found that the inherent increase in stability that comes from a high frame rate leads to the possibility of manually manipulating the sample while maintaining a sharp image, allowing real-time user interaction with the AFM. The possible application of the VideoAFM approach for the very rapid analysis of surface properties and, ultimately, surface chemistry is discussed and some possible routes are given. 相似文献
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Effects of Mineral Dissolution Ratios on Chemical-Dissolution Front Instability in Fluid-Saturated Porous Media 总被引:1,自引:0,他引:1
The main purpose of this article is to investigate, both theoretically and computationally, the effects of mineral dissolution
ratios on the different respects of chemical-dissolution front instability problems in fluid-saturated porous media. In order
to get a better understanding of how the mineral dissolution ratio affects the propagation and evolution of a planar chemical-dissolution
front in an infinite space consisting of a fluid-saturated porous medium, the theoretical analysis method is used to derive
the generous solution to the propagation speed of the planar chemical-dissolution front, while the computational simulation
method is employed to simulate the detailed evolution process when the planar chemical-dissolution front is evolved into complicated
morphologies at the supercritical Zhao numbers. The related theoretical results reveal that the mineral dissolution ratio plays an important role in controlling
the propagation speed of a planar chemical-dissolution front in the fluid-saturated porous medium. An increase in the value
of the mineral dissolution ratio can result in a remarkable decrease in the value of the propagation speed of a planar chemical-dissolution
front. On the other hand, the related computational simulation results demonstrate that the mineral dissolution ratio has
a considerable influence on the evolution pattern of a planar chemical-dissolution front during its propagation in the fluid-saturated
porous medium. An increase in the mineral dissolution ratio can reduce the likelihood for a planar chemical-dissolution front
to evolve from the initial planar shape into different morphologies within the fluid-saturated porous medium of finite size. 相似文献
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Norbornene derivatives from a metal‐free,strain‐promoted cycloaddition reaction: New building blocks for ring‐opening metathesis polymerization reactions 下载免费PDF全文
Christopher E. Hobbs Binhong Lin Thomas Malinski 《Journal of polymer science. Part A, Polymer chemistry》2015,53(20):2357-2362
The preparation of new ring opening metathesis polymerization (ROMP) monomers using a 1,3‐dipolar cycloaddition between aryl azides and norbornadiene is described. Various norbornenetriazolines, obtained through a solvent‐and catalyst‐free reaction, can subsequently be incorporated into polymer backbones through ROMP reactions. Furthermore, thermal decomposition of the triazoline moiety can allow for further polymer functionalization. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015 , 53, 2357–2362 相似文献
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