34 Result(s)

Article

The production of open-hearth phosphate slags at the “Azovstal” Works

F. F. Sviridenko, A. N. Popova in Metallurgist (1958)

Article

Properties of the amino group in N-(aminophenyl)pyridinium perchlorates

The pyridinium ring as a substituent in aniline is an electron acceptor, the effect of which is comparable to the effect of NO₂ and N(CH₃)₂ groups. Correlation of the reactivities with the basicities of the amino...

G. N. Dorofeenko, Yu. P. Andreichikov… in Chemistry of Heterocyclic Compounds (1974)

Article

Basicities and transformations of pyrylium and pyridinium salts containing p-aminophenyl substituents

On the basis of the measured basicity constants of pyrylium and pyridinium salts containing p-aminophenyl substituents it is shown that the positive charge in the pyrylium cation is considerably higher than in...

É. A. Zvezdina, V. V. Derbenev, V. A. Bren… in Chemistry of Heterocyclic Compounds (1976)

Article

Reactions of heterocyclic cations with nitrogen-containing nucleophiles. 10. Synthesis of 3,5,7-triaryl-1,2-oxazepinium perchlorates by the reaction of 2,4,6-triarylpyrylium salts with nitrones and substituted hydroxylamines

2-Substituted 3,5,7-triaryl-1,2-oxazepinium perchlorates were obtained by the reaction of 2,4,6-triarylpyrylium salts in dimethylformamide with nitrones and N-arylhydroxylamines. The products are the first rep...

É. A. Zvezdina, O. M. Golyanskaya, I. M. Andreeva… in Chemistry of Heterocyclic Compounds (1982)

Article

Reactions of heterocyclic cations with nitrogen-containing nucleophiles. 12. Reaction of pyrylium salts with azomethines

The reaction of pyrylium salts with azomethines leads to the formation of styrylpyrylium, styrylpyridinium, and 4-arylbenzylaminopyrylium salts. The reaction of the latter with ammonia and amines gave pyridine...

É. A. Zvezdina, A. N. Popova, G. N. Dorofeenko in Chemistry of Heterocyclic Compounds (1982)

Article

Reactions of heterocyclic cations with nitrogen-containing nucleophiles. 11. Reaction of 2,6-diphenylpyrylium perchlorate with primary amines, hydrazine, and hydroxylamine

The reaction of 2,6-diphenylpyrylium perchlorate with methylamine and various anilines in acetic acid leads to pyridinium salts; 3,4-bispyridinium perchlorates were obtained in dimethylformamide. The reaction ...

É. A. Zvezdina, A. N. Popova, A. I. Pyshchev… in Chemistry of Heterocyclic Compounds (1982)

Article

Synthesis of 4-(4-pyrazolyl)-substituted pyrylium salts and pyridines

A. N. Popova, S. M. Statsenko, É. A. Zvezdina in Chemistry of Heterocyclic Compounds (1982)

Article

Structure of nanosize bimetals Fe-Co and Fe-Ni

The phase composition and structural features of nano-size powders of Fe-Co and Fe-Ni systems synthesized by reducing the metal salts from strongly alkaline aqueous solutions are investigated by XAFS (XANES/EX...

Yu. A. Zakharov, V. M. Pugachev… in Bulletin of the Russian Academy of Science… (2013)

Article

X-ray diffraction analysis of the crystal structures of different graphites

Graphites of different nature—pyrolytic, synthetic, thermally expanded, and natural graphites—were compared using X-ray diffraction analysis based on the (00l) reflection from the main crystal face. It was found ...

Ch. N. Barnakov, G. P. Khokhlova, V. Yu. Malysheva, A. N. Popova… in Solid Fuel Chemistry (2015)

Article

Effect of heat treatment conditions on the catalytic graphitization of coal-tar pitch

The effect of heat treatment conditions on the properties of carbon materials obtained in the process of the low-temperature graphitization of coal-tar pitch in the presence of a cellular graphite catalyst was...

G. P. Khokhlova, Ch. N. Barnakov, V. Yu. Malysheva, A. N. Popova… in Solid Fuel Chemistry (2015)

Article

Influence of carbon additives on the thermal transformation of coal pitch

The influence of carbon additives with different texture on the thermal transformation of coal pitch is studied. The additives considered are Kemerit carbon nanomaterial, Taunit M nanotubes, AG-3 active coal, ...

G. P. Khokhlova, Ch. N. Barnakov, A. N. Popova, L. M. Khitsova in Coke and Chemistry (2015)

Article

Carbonization of coal pitch with graphite additives

The influence of added pyrolytic graphite and graphite foam on the crystalline structure of the product formed in the carbonization of moderate-temperature coal pitch at 900°C is investigated by X-ray diffract...

G. P. Khokhlova, Ch. N. Barnakov, A. N. Popova in Coke and Chemistry (2016)

Article

Structure and conductivity of carbon materials produced from coal pitch with carbon additives

Attention focuses on the structure and electrical conductivity of carbon materials obtained by the carbonization of coal pitch in the presence of additives (nanotubes, graphite foam, and graphite), at temperat...

Ch. N. Barnakov, G. P. Khokhlova, A. N. Popova, A. I. Romanenko… in Coke and Chemistry (2017)

Article

Crystallographic analysis of graphite by X-Ray diffraction

X-ray diffraction is a widely used nondestructive method of studying carbon materials. It is employed to study the phase composition of samples, to analyze the qualitative and quantitative composition of speci...

A. N. Popova in Coke and Chemistry (2017)

Article

Producing Hexane-Insoluble Asphaltene Films from Coal Pitch

The possibility of producing hexane-insoluble asphaltenes from a toluene solution of mid-temperature coal pitch is demonstrated. The topography, morphology, and structure of films consisting of asphaltene asso...

S. A. Sozinov, L. V. Sotnikova, A. N. Popova, R. P. Kolmykov… in Coke and Chemistry (2018)

Article

Electrical Conductivity of Carbon Materials Based on Coal-Tar Pitch with Added Graphite Foam

Attention focuses on the structure and electrical conductivity of carbon materials produced by the carbonization (at 900°C) of coal-tar pitch with the addition of 0.03–0.3% graphite foam and oxidized graphite ...

Ch. N. Barnakov, G. P. Khokhlova, A. N. Popova, A. I. Romanenko in Coke and Chemistry (2018)

Article

Fabrication and physicochemical characterization of graphene oxide derived from thermally expanded graphite

Graphene oxide was obtained from expanded graphite according to the modified Hummers method. The reaction time was significantly reduced (from 24 to 8 h) by applying the expanded graphite in the oxidation proc...

L. V. Ilkevich, T. B. Tkachenko, A. V. Samarov, A. A. Burtsev… in Russian Chemical Bulletin (2018)

Article

The Ion-Exchange Properties of Polymeric Zirconium Phosphate and Zirconium Dioxide

The ion-exchange properties of polymeric zirconium phosphate and zirconium dioxide were studied and their ion-exchange capacities with respect to pyridine bases and pyridinecarboxylic acids were determined. Th...

G. N. Altshuler, N. V. Malyshenko, A. N. Popova in Inorganic Materials: Applied Research (2018)

Article

Thermal-Decomposition Products of Hexane-Insoluble Asphaltenes from Coal Pitch

The thermal-destruction products of hexane-insoluble asphaltenes from coal pitch and petroleum asphaltenes are compared. The volatile thermal-decomposition products of the asphaltenes are studied by thermal an...

S. A. Sozinov, L. V. Sotnikova, A. N. Popova, L. M. Hitsova in Coke and Chemistry (2018)

Article

Phase transformations in Cd–Ni nanostructured system at elevated temperatures

Using X-ray diffraction (both in vacuum and in air), derivatomass-spectrometry and thermo-programmed oxidation, phase transformations in nanostructured Cd–Ni system occurring while heating up 720 °C were descr...

V. M. Pugachev, Yu. A. Zakharov, A. S. Valnyukova… in Russian Chemical Bulletin (2019)