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61.
Wiesław Pusz 《Communications in Mathematical Physics》1993,152(3):591-626
A complete classification of irreducible unitary representations of a one parameter deformationS
q
L(2,C) (0<q<1) ofSL(2,C) is given. It shows that in spite of a popular belief the representation theory forS
q
L(2,C) is not a smooth deformation of the one forSL(2,C). 相似文献
62.
Milanowska J Polit A Wasylewski Z Gruszecki WI 《Journal of photochemistry and photobiology. B, Biology》2003,72(1-3):1-9
Two-component monomolecular layers were formed with DPPC and two stereoisomers of zeaxanthin 9-cis and 13-cis at the argon-water interface. Very distinct over-additivity which represents affection of a lipid arrangement in the membrane has been observed in the case of zeaxanthin 9-cis (maximum at 20 mol%) but not in the case of zeaxanthin 13-cis. The differences in the organization of the isomers of zeaxanthin-DPPC monolayers are interpreted in terms of the different orientation of both xanthophylls at the interface observed at relatively high surface pressures (>25 mN/m) comparable to the surface pressures of biomembranes. The results are consistent with the model according to which zeaxanthin 9-cis adopts a vertical orientation at the polar-nonpolar interface in contrast to zeaxanthin 13-cis, which is oriented horizontally owing to the fact that it interacts by two hydroxyl groups with the same hydrophobic-hydrophilic interface in the monolayer. The findings are discussed in comparison with the behavior of zeaxanthin in the conformation all-trans in the same system. Zeaxanthin all-trans forms efficiently molecular aggregates in the mixed monolayers in contrast to cis isomers. Circular dichroism measurements show the formation of molecular structures by zeaxanthin 13-cis that are interpreted as dimers. FTIR measurements show that these dimers are stabilized by van der Waals interactions unlike aggregated structures formed by all-trans zeaxanthin that are stabilized by hydrogen bonding. Physiological importance of the differences in aggregation and orientation of stereoisomers of zeaxanthin in lipid environment is discussed. 相似文献
63.
A new catalytic method for the determination of divalent sulphur compounds, which are soluble or insoluble in water, based on the iodine–azide reaction in various alcoholic solutions is described. As model divalent sulphur catalysts the sodium sulphide and thiourea were chosen. Determination of ethylenethiourea in alcoholic extracts from apples and bananas was an example of practical application of the proposed method. To that purpose five previous elaborated techniques were adopted: titration, volumetric, gas chromatographic, enthalpimetric and potentiometric. The effect of other organic solvents, salts, acids and pH on the determination of divalent sulphur catalysts was also evaluated. 相似文献
64.
65.
66.
Summary A method for determining cyclo C6-C7-peroxides and hydroperoxides by high-resolution capillary GC has been developed. The compounds were synthesized in the liquid
phase and identified in chromatograms of the reaction mixture of cyclohexyl hydroperoxide and cycloheptane using GC-MS. Peroxy
compounds were determined using an FID. The effective carbon number (ECN) concept was used to calculate response factors of
the peroxy compounds analysed. The experimentally determined response factor for cyclohexyl hydroperoxide was identical (within
error limits) with that calculated. 相似文献
67.
Katarzyna Materna Wilhelm J. Tic Adam Sokołowski Wiesław Hreczuch 《Central European Journal of Chemistry》2011,9(2):300-307
A series of ethoxylates of 2,2,4-trimethyl-1,3-pentanediol mono-isobutyrate representing a synthetic C12 hydroxyester hydrophobe
was obtained. The solubility parameters, surface tension and critical micelle concentrations for model solutions were investigated.
The new surfactants were found to produce extremely low foam levels and a non-standard surface interfacial behavior was determined.
It was observed that the ethoxylates of the C12 hydroxyester formed an oriented monolayer at the interface regardless of their
average polyaddition degree. Such behavior is different from the surface activities of commonly known linear nonionic surfactants
and it indicates self organization of the surfactants at the interface. This feature offers possibility for application of
these surfactants in nanotechnology as well as in the conventional cleaning processes. 相似文献
68.
Katarzyna Guzow Magda Milewska Cezary Czaplewski Wiesław Wiczk 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2010,75(2):773-781
The structure and spectroscopic properties of 5-methyl-2-(8-quinolinyl)benzoxazole and its complexes with Zn(II) ion were studied using a DFT and TD DFT methods with def2-TZVP basis set. It was shown that the type of functional used (B3-LYP or pbe0) implemented in TURBOMOLE package does not have essential influence on the geometry (small differences in bond length, valence and dihedral angles) of studied compounds in both ground and excited states. However, significant differences were obtained for the position of vertical absorption and emission transition but not for the oscillator strength of transition. Application of pbe0 functional seems to reproduce better the experimental spectrum. 相似文献
69.
The Standard Model of strong and electroweak interactions uses point-like spin 1/2 particles as the building bricks of matter and point-like spin 1 particles as the force carriers. One of the most important questions to be answered by the present and future particle physics experiments is whether the elementary spin 0 particles exist, and if they do, what are their interactions with the spin 1/2 and spin 1 particles. Spin 0 particles have been searched extensively over the last decades. Several initial claims of their discoveries were finally disproved in the final experimental scrutiny process. The recent observation of the excess of events at the LHC in the final states involving a pair of vector bosons, or photons, is commonly interpreted as the discovery of the first elementary scalar particle, the Higgs boson. In this paper we recall examples of claims and subsequent disillusions in precedent searches spin 0 particles. We address the question if the LHC Higgs discovery can already be taken for granted, or, as it turned out important in the past, whether it requires a further experimental scrutiny before the existence of the first ever found elementary scalar particle is proven beyond any doubt. An example of the Double Drell–Yan process for which such a scrutiny is indispensable is discussed in some detail. 相似文献
70.
Wies?aw ?liwa 《Indagationes Mathematicae》2009,20(2):261-271
It is known that no non-Archimedean LB-space (and no strict non-Archimedean LF-space) is metrizable. We show that there exist many metrizable (or even normable) non-Archimedean LF-spaces. We prove that every non-normable polar non-Archimedean Fréchet space (and every non-Archimedean Banach space with an infinite basis (xα)) contains a dense subspace which is an LF-space. 相似文献