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Semigroup Forum - A nilmonoid is a nilsemigroup N with an identity element adjoined. New properties of the canonical presentation of N yield a more precise characterization of 2-cocycles,... 相似文献
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Régis Brugiere et Pierre Lucasson 《辐射效应与固体损伤》2013,168(1):55-57
The nature of the electron bombarded aluminium electrical recovery process has been studied by combining quenches with irradiations. Measured Frenkel pair formation rates per incident electrons as well as annealing kinetics emphasize the role of impurity interstitial trapping. 相似文献
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NMR line‐fitting quantification of polysaccharide N‐acylurea‐based modification in glycoconjugates of Salmonella Typhi Vi polysaccharide 下载免费PDF全文
Raine Garrido Jean Pierre Soubal Leonid Torres Ubel Ramírez Vicente Vérez 《Magnetic resonance in chemistry : MRC》2017,55(8):720-723
The polysaccharides modification via carbodiimide reaction is one of the most applied methods for obtaining conjugated vaccines against Salmonella enterica. However, N‐acylurea carbodiimide adduct generated in the process is a critical impurity in carbohydrate‐based vaccines. A quantitative NMR method was developed for assessing the N‐acylurea carbodiimide adduct impurity. The procedure was based on line‐fitting facilities for processing the NMR signals on complex spectra. The method showed good linearity, accuracy and precision under inter‐operator variation (relative standard deviation <5%). Copyright © 2017 John Wiley & Sons, Ltd. 相似文献
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Abstract The chemical dehydrochlorination of polyvinyl chloride was studied in solution in tetrahydrofuran. The dehydrochlorinated products were characterized by their chlorine contents and by UV/visible spectroscopy. The absorption spectra of dehydrochlorinated PVC consist of a series of absorption maxima between 200 and 600 nm due to the formation of conjugated polyenic sequences. In this article we describe a new method for polyenic sequences evaluation based on deconvolution of the experimental spectrum. A comparison with the former technique usually employed is presented. 相似文献
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The values of the CH3/CH2 ratios measured from accumulated NMR spectra of polyethylenes samples are in good agreement with those obtained from conventional IR techniques. Because NMR does not require calibration, systematic errors could be less important. Owing to the estimated values of the CH/CH3 ratios, tetrasubstituted carbon atoms are present in all the high-pressure polyethylene specimens. 相似文献
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Bis(trimethylsilyl) peroxide can be readily obtained by reaction of trimethylchlorosilane with the hexamethylenetetramine-hydrogene peroxide complex. 相似文献