By methods of electron microscopy, adsorption porometry, NMR, IR- EPR spectroscopy, X-ray diffractometry, thermal analysis, chromatography-mass spectrometry the composition, structure and particle morphology β- α2-fraction powders medium-temperature coal ash were investigated. The coke residues depending on heating temperature Polyaromatic hydrocarbons in composition volatile products thermolysis found to be formed mainly by decomposition components β-fraction. results obtained are interest...

Abstract In this work, on the example of bimetallic systems FePt and FePd, an approach is developed to assessing structural parameters nanoscale mono-and polymetallic by transmission electron microscopy (TEM), in comparison with X-ray diffraction method analysis. The interplanar distances, average sizes phase compositions FePd nanosystems are calculated.

Abstract The paper compares some characteristics of nanoparticles the FePt system obtained by method joint reduction solutions metal precursors using different reducing agents: an alkaline solution hydrazine hydrate and sodium tetrahydroborate. transmission electron microscopy is used to analyze shape morphology nanosized particles, according data methods X-ray diffraction, phase analysis carried out main structural parameters are evaluated. Thermal in combination with mass spectrometry...

Abstract Joint reduction with hydrazine from aqueous solutions of precursors produced nanostructured powders the Fe – Pt system in three characteristic phase regions. The samples were subjected to heat treatment range up 800 ° C and characterized at all stages by X-ray diffraction high-resolution electron microscopy; elemental composition was refined method optical emission spectroscopy inductively coupled plasma. In initially obtained samples, only a part substance is detected...

In the work by methods of XRD, TEM, SAED, XPS combined with mass-spectrometry gaseous products, SAXS, and elemental analysis samples phase compositions morphology particles nanostructured Co-Pt system synthesized method reduction hydrazine-hydrate aqueous solutions precursors were studied (in region rich in Pt for first time). It was found that composition range up to ≈ 60 at. % Co. XRD-analysis fixes as only FCC solid solution Co Pt, established upper limit solubility %18±1 At content above...

В работе методами ЭПР- и ЯМР-спектроскопии изучены процессы, протекающие при низкотемпературном пиролизе α-фракции каменноугольного пека в интервале температур 25–700 °С. Показано, что начальном до 400 °С происходят последовательные процессы: гомолитические разрывы С–С- C–H-связей → рекомбинация ароматических π-радикалов с формированием графитоподобных структур. Выявлено, достижении порогового значения температуры (500 °С) образцах начинают преобладать процессы рекомбинации радикалов....

The article reveals for the first time features of nanoparticle morphology, phase compositions, and their changes when heating FePt CoPt nanoalloys. Nanoparticles were obtained by co-reduction precursor solution mixtures with hydrazine hydrate. found a complex methods X-ray diffraction (in situ XRD scattering), TEM HR, cyclic voltammetry. In addition, adsorbometry results obtained, stability different nanocluster structures was calculated molecular dynamics method. There only FCC solid...

The work carried out comprehensive studies of a number industrial semi-cokes using EPR and NMR methods. Apply spectroscopy, it was shown that in all the studied there are two types radical structures, first which low-molecular aromatic radicals.The second type is conjugated polyaromatic unpaired electron delocalized. Line shape analyzing spectra, found differences presented line isotropic cokes. In this highly sensitive method makes possible to monitor changes molecular structure during...

Integrated studies of green coke have been carried out by means X-ray diffractometry, electron microscopy, paramagnetic resonance (EPR) and nuclear magnetic (NMR). It is determined EPR spectroscopy that two types radical structures are present in the samples: low-molecular aromatic radicals conjugated polyaromatic which unpaired delocalised. Analysis line shapes spectra reveals differences between samples under investigation. shown to be highly sensitive method allowing one follow changes...

Calculations of the total energy Fe-Pt nanoclusters, corresponding in phase diagram to compositions FePt, FePt3 intermetallics and possessing either characteristic structures L10 L12, respectively, or non-characteristic disordered structure A1, as well various particle habits (cuboctahedra, icosahedra) are carried out by molecular dynamics for first time. The dependences cluster stability on their size temperature plotted, along with schemes transformations morphology dependence melting...

Nanoparticles of the FePt and CoPt alloys are studied. Detailed structural-phase data on platinum-rich nanosystems has been obtained using a combination X-ray diffraction (XRD), selected-area electron (SAED), high-resolution transmission microscopy (HR-TEM) in scanning microscope, addition with derivatography coupled simultaneous mass spectrometry, elemental analysis samples. The upper limits Fe Co solubility Pt their temperature dependencies have defined. It is shown that, if or contents...

The work is devoted to the synthesis of nanostructured Co-Pt systems with different ratios components and study phase composition resulting products an estimate lattice parameters sizes obtained nanocrystals. Powders nanosystems were synthesized by method chemical co-reduction precursor solutions using hydrazine hydrate as a reducing agent in strongly alkaline medium. To samples, XRD structural analysis scanning electron microscopy (SEM) used. According results SEM, it can be concluded that...

Известно, что каменноугольная

В работе методом сканирующей электронной микроскопии исследованы морфология, структура и минеральный состав образца промышленного карбонизата. Согласно полученным результатам исследуемый образец карбонизата включает в себя частицы различного фракционного состава, которые покрыты органической массой, содержащей кислород. Также установлено, что входит диспергированный аморфный карбонат кальция, подтверждается уменьшением содержания кислорода на поверхности частиц после нагрева инертной...

The morphology of nanoparticles, structural-phase properties, and phase transformations that occur during heating in the nanostructured CoPt CoPd systems rich precious metals, obtained by co-reduction aqueous precursor solutions hydrazine hydrate, were studied X-ray diffraction structural analysis, small-angle scattering, high-resolution transmission electron microscopy. results are interest for development fundamentals materials science bimetallic nanoalloys, provide a key to understand...

The paper is devoted to a study of the phase composition bimetallic FePt nanoparticles synthesized by co-reduction precursor solutions an alkaline solution hydrazine hydrate. XRD structural analysis revealed solubility limit components in solid nanostructured Fe-Pt system (about 10 mol.% Fe). It was found that there difference between molar fraction iron determined method and elemental analysis. Such phenomenon made it possible put forward assumption about existence diffraction-invisible...