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501.
502.
Tatarinov P. V. Mochalova A. E. Belysheva I. V. Smirnova L. A. Bodrikov I. V. 《Russian Journal of Applied Chemistry》2010,83(7):1294-1298
Synthesis of block copolymers of chitosan with acrylamide, involving formation of acrylamide blocks on glucosamine blocks
generated by induced degradation of chitosan macromolecules by the hydrogen peroxide-ascorbic acid system, was studied. 相似文献
503.
Leonid N. Bochkarev Alexander V. Nikitinskii Yulia E. Begantsova Vladislav I. Shcherbakov Natalia E. Stolyarova Irina K. Grigorieva Irina P. Malysheva Galina V. Basova Georgii K. Fukin Evgenii V. Baranov Yurii A. Kurskii Gleb A. Abakumov 《Journal of organometallic chemistry》2005,690(13):3212-3216
The novel germanium-containing alkylidene complexes of molybdenum R3Ge-CHMo(NAr)(OCMe2CF3)2 (Ar = 2,6-i-Pr2C6H3; R = Me, Ph) have been prepared by the reaction of organogermanium vinyl reagents R3 GeCHCH2 with known alkylidene compounds Alkyl-CHMo(NAr)(OCMe2CF3)2 (Alkyl = But, PhMe2C). The titled compounds were isolated as crystalline solids and characterized by elemental analysis, 1H NMR, 13C NMR spectroscopy and X-ray diffraction studies. The geometry of the Mo atoms in the compounds can be described as a distorted tetrahedron. 相似文献
504.
Yulia Polevaya Joshua Samuel Michael Ottolenghi David Avnir 《Journal of Sol-Gel Science and Technology》1995,5(1):65-70
Nitrogen adsorption at −195°C serves as routine method for the measurement of surface area of porous materials derived by
sol-gel procedures. In a systematic study of the simultaneous effect of the pH and water-silane ratio of the starting solutions
of preparation of SiO2 xerogels on their surface areas, it was found that conditions of high acidity and low water/silane ratio result in microporous
materials, the surface of which cannot be accessed by N2 at −195°C, within a realistic time scale, but only by CO2 at 0°C. In a typical result for TMOS/water/methanol = 1/2/3 at pH=1.0, the apparent N2-area was zero, while the CO2-area was 414 m2/gr. It is recommended to recheck apparent N2-low surface areas of sol-gel materials by CO2 adsorption. The behavior of pyrene-doped xerogels of this type is in agreement with the structural characterization by adsorption. 相似文献
505.
A. E. Mochalova N. V. Zaborshchikova A. A. Knyazev L. A. Smirnova V. A. Izvozchikova V. V. Medvedeva Yu. D. Semchikov 《Polymer Science Series A》2006,48(9):918-923
Graft copolymers have been prepared through the free-radical polymerization of acrylamide in water-acetic acid solutions of chitosan in the presence of ammonium persulfate as an initiator. The effect of temperature, pH of a medium, and concentrations of initiator, chitosan, and acrylamide on the grafting kinetics and efficiency has been established. The local concentration of acrylamide in the reaction zone increases due to intermolecular hydrogen bonding between polysaccharide and monomer molecules. Copolymer films are characterized by better mechanical properties compared to those of polysaccharide. Hydrogels with good viscoelastic properties have been obtained when grafting was performed in the presence of N,N-methylenebisacrylamide as a crosslinking agent. 相似文献
506.
Self‐Controlled Monofunctionalization of Quantum Dots for Multiplexed Protein Tracking in Live Cells
Changjiang You Dr. Stephan Wilmes Oliver Beutel Sara Löchte Yulia Podoplelowa Friedrich Roder Christian Richter Thomas Seine Dirk Schaible Gilles Uzé Dr. Samuel Clarke Dr. Fabien Pinaud Dr. Maxime Dahan Dr. Jacob Piehler Prof. Dr. 《Angewandte Chemie (International ed. in English)》2010,49(24):4108-4112
507.
508.
Marian Plotkin Stanislav Volynchik Natalya Y. Ermakov Avishai Benyamini Yulia Boiko David J. Bergman Jacob S. Ishay 《Photochemistry and photobiology》2009,85(4):955-961
The Oriental hornet bears both brown and yellow colors on its cuticle. The brown component is contributed by the pigment melanin, which is dispersed in the brown cuticle and provides protection against insolation, while the yellow‐colored part contains within pockets in the cuticle granules possessing a yellow pigment. These yellow granules (YG) are formed about 2 days prior to eclosion of the imago, and their production continues for about 3 days posteclosion. Xanthopterin is the main component of the granule and lends it its yellow color. Xanthopterin produces a characteristic excitation/emission maximum at 386/456 nm. Characterization by use of mass spectrometry showed the compound to have a molecular ion of 179, as expected from xanthopterin. Spectroscopic examination of the absorption of an entire stripe of yellow cuticle in the course of its metamorphosis revealed that the absorption steadily increases throughout the process to a maximal level of absorption about 3 days posteclosion. In the absence of the YG, the cuticle is permeable to the passage of all wavelengths within the visible range and to the UV range (290–750 nm) in all age groups of hornets. The newly ecloded hornets depart the nest to engage in activities requiring exposure to insolation only as the process of granule formation terminates, namely, when the layer of YG in the cuticle suffices to absorb all the harmful UV radiation. 相似文献
509.
V. M. Mochalova A. V. Utkin A. V. Anan’in 《Russian Journal of Physical Chemistry B, Focus on Physics》2007,1(6):576-580
The reaction zones of steady detonation waves in pressed 2′,2′,2′-trinitroethyl-4,4,4-trinitrobutyrate (TNETB) charges with densities within 1.23–1.79 g/cm3 and initial powder dispersities of 5 and 80 μm were studied with the use of a VISAR interferometer. It was demonstrated that the boundaries of the initial density range within which a pressure growth is observed instead of a chemical spike, predicted by the theory, are determined by the HE dispersity. The measured dependence of the detonation velocity on the initial HE density exhibits features suggestive of an underdriven detonation wave without a chemical spike. The peculiarities observed are accounted for by the heterogeneous structure of pressed HEs, the decomposition of which is of hot-spot character, occurring partly in the compression wave front. 相似文献
510.