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  • Synthesis and spectroscopic analysis of the structure and oxidizing ability of Fe3O4 magnetic fluid nanoparticles.

    In this paper we investigated the structure of the magnetic fluid based on Fe3O4 nanoparticles. Magnetic fluid based on Fe3O4 nanoparticles is used for cancer treatment, targeted drug delivery, hyperthermia, as a contrast agent in surgery, as a barrier to blood flow and others. Magnetic fluid based on Fe3O4 nanoparticles was synthesized by chemical condensation of magnetite nanoparticles. Characteristics of magnetic fluid (oxidation of iron nanoparticles size, density) were investigated using X-ray absorption spectroscopy. The changes of the antitumor effect of the magnetic fluid is associated with an increase of the particle size of the iron oxide that has a significant impact on their penetration in a tumor tissue.

    Keywords: magnetic fluid, magnetite, nanoparticles, Fe3O4, oxidation state, density, antitumor activity

  • Spectroscopic study of the structure of transition metal nanoparticles, with pronounced antitumor activity.

    In this work, the nanoparticles were investigated biogenic metals iron, fine and coarse copper nanoparticles, the nanoparticles of zinc test samples showed pronounced antitumor activity in the body tumor-bearing rats. Nanoparticles were introduced into the body of rats as a solution in sodium chloride .On laboratory X-ray absorption spectrometer R-XAS Looper were measured X-ray absorption spectra (XANES) of reference samples of iron, copper, zinc foil, iron oxide, copper, zinc and investigated nanoparticles. Based on the data, it was concluded that their structure, charge state and redox pure powders and sodium chloride.

    Keywords: magnetic fluid, magnetite, nanoparticles, Fe3O4, oxidation state, density, antitumor activity

  • Special features of mechanochemical activation Al-Si mixture and the formation of hot-deformed powder material based on the mixture

    This paper presented the study of the mechanochemical activation powder mix in dry and liquid grinding media, accompanied by agglomeration of the particles. It Is shown that when agglomerate particles having a bimodal size distribution is forming during the treatment in a dry grinding media and partially (2 wt % ) decaying at grinding by pestle in mortar. The transition to liquid grinding media is leading to a unimodal size distribution and increasing dispersion of the agglomerated particles, characterized by secondary agglomerating when using the alcohol and destruction when using activation in saturated aqueous solution of boric acid. Inherited effect mechanical activation parameters on the compaction process during cold compaction and hot stamping has been determined. Application treated in a high energy mill in an grinding media saturated aqueous H3BO3 Al-Si powder mix results in the formation of moldings with low cold-pressing relative density (0.735) and the activation of the hot stamping compaction (|εh| = 0,592) providing production of hot-deformed powder material with increased mechanical properties.

    Keywords: mechanochemical activation, hot-deformed powder material, aluminum, silicon, dispersion, agglomeration

  • Synthesis and electrochemical properties of LiMn1/3Cr1/3Fe1/3O2 solid solution with the structure of α-NaFeO2

    The solid solution of  LiMn1/3Cr1/3Fe1/3O2 with the structure of α-NaFeO2  isostructural with the widely used LiCoO2  has been synthesized and investigated as a cathode material. Rated voltage of LiMn1/3Cr1/3Fe1/3O2  relative to the lithium is 4 V.  The possibility of charging − discharging the material to a specific capacity of 220-250 mAh/g at currents of C/15-C/50 without phase transformations has been experimentally demonstrated. 

    Keywords: lithium-ion batteries, cathode materials, Delafosse, solid solution, X-ray structural analysis, electrochemical properties

  • Local Atomic and Electronic Structure of the Fe dopants in AlN:Fe Nanorods

    Fe-doped AlN nanorods were studied by means of x-ray absorption spectroscopy above the Fe K- and L2,3- edges. Theoretical simulations of the x-ray absorption spectra show that Fe atoms mainly substitute Al. A minor fraction of Fe interstitials or Fe-Al-N ternary alloy can be identified as well. Bader’s AIM analysis predicts that neutral substitutional FeAl defect is in 2+ charge state, though Al in pure AlN is in 3+ charge state.  Fe L2,3 absorption spectra and photoluminescence data indicate the coexistence of Fe2+/Fe3+ in AlN:Fe nanorods so different charge states of substitutional FeAl should co-exist.

    Keywords: diversification of management, production diversification, financial and economic purposes of a diversification, technological purposes of ensuring flexibility of production

  • Local atomic and electronic structure of nanostructured condensed materials for rechargeable current sources on the basis of V2O5/Fe/LiF nanocomposite within charge-discharge cycle

    In this paper we study of the local atomic and electronic structure of nanostructured condensed material for rechargeable current sources on the basis of 15mas.%V2O5/Fe/LiF nanocomposite within charge-discharge cycle. Principle component analysis (PCA) of the series of Fe K-edge spectra collected during 1 st charge showing the concentrations of the components Fe, FeF2 and V[FeV]O4. We found the changes in the V oxidation state from the analysis of the experimental Fe K- and V K- XANES spectra. Total and partial density of states of components are presented.

    Keywords: nanostructured materials for rechargeable current sources, dynamics of local atomic and electronic structures, XANES, DFT

  • "Methods of determining the grain boundary diffusion coefficient impurities in metals on the basis of numerical solutions for the Fisher model"

    In the introduction the relevance of the study of diffusion along grain boundaries in metals. The aim of the work was to develop a method for determining the diffusion coefficient of impurity atoms at the grain boundaries in metals based on the numerical solution of the model by Fisher. The methodology laid plotting the ratio of the depth of bulk diffusion and grain boundary diffusion on the ratio of the diffusion coefficients of impurity atoms in them. In the construction of numerical solutions available to simplify the modeling of the physical nature of the process of diffusion along grain boundaries. The technique may be used in experiments with widely varying parameters diffusion annealing. Examples of the application procedure. The estimation of the coefficient of grain-boundary diffusion of copper in polycrystalline nickel. Also calculated the ratio of maximal depth of diffusion of silver in the grain and the grain boundary in the SMC copper.

    Keywords: diversification of management, production diversification, financial and economic purposes of a diversification, technological purposes of ensuring flexibility of production

  • Development of elements for "smart clothes" based on the electrochemical charge storage system for microsystems technique

    In this paper we propose basic geometric, mass and electrical parameters of the element for collection of static electricity from the surface of the textile. This element is a reversible electrochemical charge storage system based on nanostructured nickel oxide and carbon cloth. Element has a planar structure, it is flexible, lightweight, safety and ergonomic. Proposed element can be used as a power source for the Microsystems technique in "smart clothes".

    Keywords: "smart clothes", microsystems technique, static electricity, supercapacitor, composite material NiO/C

  • Gold nanoparticles functionalisation by long-chain thiol and amine ligands: study of local atomic and electronic structure of ligand-gold bond

    In the present work we report on the study of local atomic and electronic structure of gold nanoparticles funnctionalised by thiol and amine containing long-chain ligands. The study of nanoscale atomic structure is performed by means of X-ray absorption spectroscopy (XANES: X-ray Absorption Near-Edge Structure) and computer simulation. In consequence of the experimantally obtained data analysis and computer simulation it was obtained that strong bonding takes place when 11-mercaptoundecanoic acid is bound to the gold nanoparticles surface, forming a chemical bond Au-S 0.25 nm in length. Weaker bonding is observed when forming bond between dodecylamine and gold nanoparticles surface atom resulting in Au-N bond 0.23 nm in length. Supplementary XANES spectra analysis by means of density functional theory reveals the nature of formation of the investigated nanoscale structure.

    Keywords: nanoscale structure of matter, X-ray absorption spectroscopy, XANES, density functional theory, nanoparticles functionalisation

  • Study of the catalytic ability of the nanosized catalysts based on CeO2 during catalytic reaction

    The nano-catalyst ceria (CeO2), activated by Pt nanoparticles, is known for being prospective and efficient material widely used in catalysis, fuel elements, and sensors. One of the most up-to-date methods of catalysts' reasearch is X-ray absorption spectroscopy (XAS) that is sensitive to the chemical state of catalyst's active centers [1,2]. Using XAS in the fluorescense detection mode at CeL1 line with high precision we studied electronic structure of Pt-activated nanoparticles of ceria at various redox conditions. In order to detect partial X-ray fluorescence yield the emission line CeLγ3 was used, which allowed us to increase spectral resolution. We researched local atomic and electronic structure of the materials under study. Oxygen vacansies were found to appear on the nanoparticles surface of ceria at 5% CO He atmosphere. Theoretical modeling of the obtained spectra at CeL1-edge demonstrated good agreement with experiment.

    Keywords: X-ray absorption spectroscopy, HERFD, XAS, Ce-based catalysts, oxygen vacansies

  • Local Atomic Structure and Computer Modeling of the Copper Ion in Amyloid Beta Peptide: XAS Study

    Alzheimer's disease is an incurable illness. It affects about half a million people in Russia, and due to the general trend towards aging of the population the number of Alzheimer's disease cases will steadily increase. Insoluble deposits of amyloid beta in the brain tissue (amyloid plaques) are the major morphological characteristic of Alzheimer's disease. It has been found that the increased concentration of copper in amyloid plaques results in copper ions bound to the protein. It is the presence of copper in the binding site triggers of the formation of amyloid plaques. Therefore, the study of the binding site in amyloid beta is of great scientific interest. The local atomic structure of the Cu(I) copper ion binding site in the amyloid beta peptide has been studied by means of XANES spectroscopy. Several model structures obtained by molecular mechanics and density functional theory (ADF code) have been tested. Theoretical analysis of X-ray absorption spectra based on the finite difference method implemented in FDMNES code was performed. An appropriate model structure of the Cu(I) copper ion binding site in amyloid beta peptide has been found.

    Keywords: amyloid beta, binding site, Alzheimer's disease, the method of finite differences, Cu(I)

  • In-situ XANES technique to study of the catalysts

    This paper describes an in-situ experimental technique to study of ceria nanocatalysts by using X-ray absorption near edge spectroscopy XANES. This technique allows us to determine Ce3+ concentration inside ceria nanoparticles in the course of catalytic reaction based on the comparison and divergence minimization of the Ce L3 XANES spectrum of the ceria nanoparticles under catalysts (atmosphere, temperature) with a linear combination of two independent components corresponding to spectra of Ce4+ ion of the CeO2 structure and Ce3+ ion of the theoretical Ce2O3 structure. The calculated weight ratio determines the Ce3 + concentration in the sample during the catalytic reactions.

    Keywords: in-situ X-ray absorption spectroscopy, HERFD, XAS, ceria nanoparticles, Ce-based catalysts, Ce3+ concentration

  • Raman spectra on three phase transitions of perchlorate of natrium

    The analysis of temperature dependence of frequencies of lines  is conducted active in the spectrums of combination dispersion of  perchlorate of natrium. The theory analysis of spectrums is conducted.

    Keywords: Perchlorat of natrium, anion, spectrums of combination dispersion, phase change

  • Symmetry of anions in molten solts and raman spectra

    The values  the frequencies of the stretching vibrations of anions  SCN-,  NO2-, NO3-, CℓO4- in molten salts of alkali metals and their point group symmetry. There is a correlation with an increase in the frequency of symmetry  

    Keywords: Raman Spectra; anions; molten solts; group symmetry.

  • Local atomic structure dynamics of new nanostructured condensed materials for rechargeable current sources on the basis of V2O5/Fe/LiF nanocomposite within charge-discharge cycle

    In this paper we study the dynamics of the local atomic structure of new nanostructured condensed material for for rechargeable current sources on the basis of 15mas.%V2O5/Fe/LiF nanocomposite within charge-discharge cycle on the basis of X-ray diffraction (XRD), X-ray absorption spectroscopy (XANES) and of computer simulation. The analysis of the experimental data obtained during the first charge cycle reveals the transformation of iron to more than 50% of iron fluoride (II) , Li ions intercalate into the structure of amorphous V2O5 forming LiVO2 compound.

    Keywords: diversification of management, production diversification, financial and economic purposes of a diversification, technological purposes of ensuring flexibility of production