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Conclusions A simple and convenient method for analyzing polysaccharide fractions isolated from natural sources has been proposed.The method is based on ion-exchange chromatography on DEAE-cellulose and gel filtration on Bio-Gels using small columns and automatic monitoring of the separation with the aid of a flow-through ultraviolet densitometer. The method is characterized by rapidity and good reproducibility.Khimiya Prirodnykh Soedinenii, Vol. 5, No. 4, pp. 203–206, 1969 相似文献
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E. N. Adamenko L. L. Frolova M. V. Panteleeva A. V. Kuchin 《Chemistry of Natural Compounds》2007,43(1):59-62
Optically active camphordihydro-2,3-pyrazine and camphorquinoxaline were prepared from camphoroquinone enantiomers. It was
shown that (1S,4R)-(+)-camphoroquinone was formed by oxidation of (1S,3R, 4R)-(−)-3-bromocamphor and (1R,4S)-(−)-camphoroquinone from (1R,3S, 4S)-(+)-3-bromocamphor, respectively. Camphor anhydride was a side product (6–10%) of the reaction.
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Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 50–52, January–February, 2007. 相似文献
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With the use of directed graphs, we study topologies on finite sets. On this basis, we propose a new classification of these
topologies. Some properties of T
0-topologies on finite sets are proved. In particular, we prove the existence, in T
0-topologies, of open sets containing any number of elements that does not exceed the cardinality of the set itself.
Translated from Ukrains'kyi Matematychnyi Zhurnal, Vol. 60, No. 7, pp. 992–996, July, 2008. 相似文献
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The photophysical properties (absorption, emission) of the (Bu4N)2[(MoII
6Cl8)L6] (L = CF3COO–, CH2=CHCOO–) cluster salts and (Bu4N)2[(MoII
6Cl8)(CF3COO)6–n]—polyacrylic acid copolymers were studied. Both the cluster-containing monomers and corresponding copolymers phosphoresce intensely ( 0.2—0.4 ms at 77—300 K). 相似文献
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This paper reports results of track registration for fast particles from the hot spot sparked inside a metal target. CR-39 track detectors placed in the ion pinhole camera, a magnetic analyzer, and Thomson-type mass-spectrometer in order were used to obtain images of the hot spot and to determine spectra of the fast particles. Using track detectors in the pinhole camera, we have obtained specific split images. The “average etch rate ratio versus track length” locus for track sample groups is depicted by means of squared diameters asymptotic method. Our analysis shows the majority of tracks belong to hydrogen nuclei. The track loci for the detectors from the pinhole or analyzers turn out to be split into two parallel streaks that have been interpreted as a proton–deuteron doublet. Data obtained using the Thomson analyzer clearly demonstrate the equal numbers of protons and deuterons for some parallel parabola sections. 相似文献