The possibility of modifying the Dreywood anthrone method for spectrophotometric determination of carbohydrates in order to
increase the accuracy and reproducibility of the results was examined. The classical method and a developed modification were
compared. The relative uncertainty in a determination by the modified method was less than 4%.
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Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 218–220, May–June, 2006. 相似文献
Binary polystyrene and poly(4‐vinylpyridine) mixed grafted silica nanoparticles (PSt/P4VP‐g‐SNPs) are fabricated using CuI‐catalyzed azide‐alkyne Huisgen cycloaddition (CuAAC) via grafting‐to method. Azide‐terminated PSt and P4VP are synthesized via post‐ and pre‐atom transfer radical polymerization modification, respectively. Then, the polymers are simultaneously anchored onto alkyne‐modified SNPs by CuAAC yielding mixed brushes as shown by Raman spectroscopy, dynamic light scattering, and thermogravimetric analysis. To the best of our knowledge, this is the first report of simultaneously grafting two distinct polymer chains to synthesize mixed grafted silica nanoparticles using CuAAC technique via grafting‐to method.
Previously, J. B. Krieger, Y. Li, and G. J. Iafrate suggested a new form of exchange correlation potential for electronic structure calculations (KLI form). This paper deals with some problems of adaptation of the KLI formalism to the scattered wave method in the cluster model. The basic approximations of the model (frozen core, muffin tin, and the form of the exchange correlation functional) are examined from the viewpoint of their effect on the results of calculations, considering the given form of the exchange correlation potential. The results of test calculations are given for isolated H, He, Mg, and Xe atoms and H2O, CH4, and CO molecules. 相似文献