New measurements for the thermal diffusion factor and for the diffusion coefficient derived from it are reported for the Ar-CO2 gaseous mixture at different temperatures and for various concentrations of the CO2 molecule. Several of the interaction potentials between the partners which have been suggested in the literature are examined, and quantum dynamics calculations are carried out to compare their performances using the infinite order sudden dynamic decoupling scheme. The present results are compared with other experiments and show clearly that, although one of the empirical potentials turns out to be the most realistic for describing such properties, a unique form of a multiproperty-tested potential energy surface for this system is still lacking. 相似文献
Russian Chemical Bulletin - The K5 capsular polysaccharide (CPS) was isolated from the bacterium Acinetobacter baumannii (A. baumannii) SDF and studied by 1D and 2D 1H and 13C NMR spectroscopy... 相似文献
Physics of Wave Phenomena - A possibility of calibrating a piezo transducer by comparing thermoacoustic and vaporization pressure signals generated in a metal (liquid mercury) irradiated with... 相似文献
The polysaccharide composition in sporophylls of the brown alga Alaria marginata enriched with laminaran and sulfated polysaccharides was studied. It was shown that laminaran molecules had an average degree of polymerization about 30 and consisted mainly of 3-linked β-D-glucopyranose residues, having no more than 10% of 1→6 linkages. The majority of chains (about 60%) were terminated at "reducing" end by mannitol residue. Alginic acid of sporophylls contained mannuronic (M) and guluronic (G) acids residues distributed along the linear polymer molecules as MM, MG, and GG blocks at a ratio of 4: 1: 1. Fucoidan was found to be composed of fucose, galactose, and sulfate as the major constituents, while xylose, mannose, glucuronic acid, and acetate were the minor components. It was shown that fucoidan contained two major components: fucan sulfate, molecules of which are built up of 3-linked fucopyranose residues with branches and sulfate groups at different positions, and fucogalactan, also containing chains of 3-linked fucopyranose residues with branches at positions 4 together with highly branched galactan chains terminated by fucose residues. The fucoidan contained also sulfated glucuronomannan and sulfated glucuronan as minor components. 相似文献
The cutting element LiF–LiVO3–LiKMoO4–KBr of the quinary reciprocal system Li, K||F, Br, VO3, MoO4 was studied by differential thermal analysis. The composition and melting point of the alloy corresponding to a quaternary eutectic were determined (7.0 mol % LiF, 32.0 mol % LiVO3, 47.7 mol % Li2MoO4 + K2MoO4, 12.3 mol % KBr, 410°С). 相似文献
Phase equilibria in the LiBr–LiVO3–Li2MoO4–KBr quaternary system (the stable tetrahedron of the quaternary reciprocal system Li, K || Br, VO3, MoO4) were studied by differential thermal analysis. The composition and melting point of a quaternary eutectic were determined: 56.7 mol % LiBr, 1.5 mol % LiVO3, 4.9 mol % Li2MoO4, 36.9 mol % KBr, 321°C. 相似文献
Capsular polysaccharide (CPS) was isolated from a nosocomial pathogen Acinetobacter baumannii (A. baumannii) NIPH67 and studied by sugar analysis, Smith degradation, and 1H and 13C NMR spectroscopy. The CPS was found to contain 5,7-diacetamido-3,5,7,9-tetradeoxy-l-glycero-l-manno-non-2-ulosonic acid (di-N-acetylpseudaminic acid, Pse5Ac7Ac), and the structure of the linear trisaccharide repeating unit of the CPS was established as →4)-α-Psep5Ac7Ac-(2→6)-β-d-Galp-(1→3)-α-d-GalpNAc-(1→. The genetic content of the capsule biosynthesis cluster of A. baumannii NIPH67, designated KL33, is consistent with the established CPS structure, and thus the capsule of the investigated strain was assigned to K33 group. Functions of proteins including two glycosyltransferases encoded by the genes of the K33 locus were assigned based on the structure of CPS and by the comparison with related proteins of other capsular types of A. baumannii. 相似文献
Several fucoidan fractions were isolated from the biomass of the Kamchatka brown alga Laminaria bongardiana by hot water extraction followed by anion-exchange chromatography. Fucoidans were found to be composed of l-fucose, d-galactose, and sulfate as the major components, whereas d-xylose, d-mannose, d-glucuronic acid, and acetate were detected as the minor constituents. Highly sulfated fucoidan fractions F-2 and F-3 were solvolytically desulfated by heating in dimethyl sulfoxide in the presence of pyridine. The structures of native and desulfated polysaccharides were investigated by the methylation analysis and NMR spectroscopy. It was shown that F-2 contains fucan sulfate, the backbone of which is made of 1→3-linked α-l-fucopyranose residues with single α-l-Fucp branches at positions 2 and sulfate groups predominantly at positions 4. Sulfated fucoglucuronomannan, fucoglucuronan, and fucogalactan were detected in F-2 as concomitant polysaccharides. Fucan sulfate and sulfated fucogalactan were the major components of the fraction F-3. The anticoagulant properties of fucoidan fractions were assessed. It was demonstrated that the activity of the fraction F-3 is comparable with that of low-molecular-weight heparin (enoxaparin), whereas the activity of total fucoidan F and the fraction F-2 is ~2/3 and ~1/2, respectively, of the activity of F-3, which is in accordance with the lower sulfate content in these samples. Desulfated preparations F-2deS and F-3deS were completely devoid of anticoagulant activity.
The composition and structure of plasma-polymerized coatings on the surface of a silicon single crystal are studied using
methods of mass spectrometry and vibrational spectroscopy. It is established that the coating on the side of the surface is
a set of ordered and unordered regions of branched chains of halogenocarbons and halogenohydrocarbons. A significant thickness
of the coating-substrate transition layer contains silicon carbide and nitrogen dissolved in carbon. A great bulk of the coating
is made up of amorphous carbon. The coating mass contains adsorbed gases that block reactive centers. Consideration is given
to the special features of recording of vibrational spectra, the coating structure, its differences over the depth, the structural
difference between the coating and a polymer film, and aging of the polymer material.
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 66, No. 3, pp. 338–344, May–June, 1999. 相似文献
Infrared and polarized Raman spectra of a K3H(SO4)2 crystal are experimentally obtained at a temperature of 92 K and at room temperature. The structural, spectral, and calorimetric measurements together confirm that the K3H(SO4)2 crystal has a monoclinic syngony and contains the dimers SO42–...O3SOH– as base units. The sulfate anions are hydrogen-bonded. 相似文献