9 results match your criteria: "Institute of Chemistry of the Komi Science Center[Affiliation]"

The pyrochlore-type solid-solution formation in a BiMgCuTaO system, synthesized for the first time, is observed at ≤ 0.56. High-temperature X-ray diffraction showed that the pyrochlore phase exists in air up to 1080 °C, where its thermal decomposition leads to the segregation of (Mg,Cu)TaO.

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In this study, electrospray deposition has been used as a method to prepare lignin submicron spherical particles. Regularities of electrospraying of lignin solutions in DMSO were revealed. The influence of voltage, distance between electrodes, feed rate, temperature and concentration of lignin solution on the morphology, size and polydispersity of the obtained particles was determined.

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A phase-pure nickel bismuth tantalate with pyrochlore structure was synthesized by a solid-phase synthesis method for the first time. The crystal structure of pyrochlore (refined formula BiNiTaO, sp. gr.

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Article Synopsis
  • The paper analyzes the chemical structure of Araucaria lignin, a unique relic plant from the Permian period, using various advanced analytical techniques.
  • It identifies distinct structural features of Araucaria lignin that set it apart from modern coniferous lignins and reveals its unique paramagnetic properties.
  • For the first time, the research classifies Araucaria lignin as compositionally heterogeneous GH lignins, a classification not seen in contemporary lignins.
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The aflatoxin B1 (AFB1) adsorption properties of several lignins isolated by the Pepper's method from grassy plants: Helianthus tuberosus (LS-1), Atriplex patula (LS-2), Rhododendron tomentosum (LS-3), Althaea officinalis (LS-4), Lavatera (LS-5), and from wood of spruce Pícea (LS-6) were studied. The adsorption was conducted in vitro in the modeled conditions of the gastrointestinal tract. The correlations between the values of adsorption-desorption and the parameters of surface-porous structure and chemical structure of the lignins were established.

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Recent advances in investigations of chemical structure of lignin give rise to questions about relationship between chemical structure and topology of the macromolecules. In this paper, we made a comparison of results of the studies of chemical and topological structures of lignins. The features of topological structure of lignins of birch and apple wood were identified on the basis of the study of dilute solutions of the lignins by the sedimentation-diffusion analysis and viscometry.

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Thermal behavior of the orthorhombic (α) and triclinic (β) polymorphs of BiNbO was studied by the methods of high-temperature powder X-ray diffraction (HTPXRD) and differential scanning calorimetry (DCS) in the temperature range 25-1200 °C. The study revealed the sequence of thermal phase transformations and the new high-temperature modification, γ-BiNbO, which was formed above 1001 °C and existed up to the melting temperature of BiNbO. The incongruent melting of BiNbO was characterized by the formation of the cubic phase with the approximate composition BiNbO.

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Caryophyllane thioterpenoids were synthesized in 23 - 81% yields. The antioxidant properties of the obtained compounds in various model systems were found. It was revealed that 4,5-epoxycaryophyll-9-ylmethanethiol has the greatest antioxidant activity.

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