排序方式: 共有41条查询结果,搜索用时 31 毫秒
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Fedyushin P. A. Serykh A. A. Vinogradov A. S. Mezhenkova T. V. Platonov V. E. Nasyrova D. I. Samigullina A. I. Fedin M. V. Zayakin I. A. Tretyakov E. V. 《Russian Chemical Bulletin》2022,71(8):1670-1678
Russian Chemical Bulletin - A method was developed for the synthesis of perfluoro-1,1′:4′,1″-terphenyl by the reaction of chloroperfluorobenzene with zinc dust followed by the... 相似文献
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L.?N.?MaskaevaEmail author V.?F.?Markov E.?A.?Fedorova I.?A.?Berg R.?F.?Samigullina V.?I.?Voronin 《Russian Journal of Applied Chemistry》2017,90(10):1572-1578
The hydrochemical precipitation method at 298 and 333 K with, respectively, thiocarbamide and sodium selenosulfate was used to obtain nanostructured powders of copper sulfide with formula composition Cu2S, which are composed of globules 200–500 nm in diameter, formed by 70–100-nm particles, and copper(I) selenide, composed of crystallites with polyhedral shape, sizes of 80 to 500 nm, and a formula composition Cu1.84Se. An X-ray diffraction analysis revealed the orthorhombic Cu2S structure (space group no. 39-Abm2) with unit cell parameters a = 1.182 nm, b = 2.705 nm, and c = 1.343 nm. Powders of Cu1.84Se copper selenide have a cubic structure (space group Fm3m) with lattice constant a = 0.5693 nm. A thermal analysis demonstrated that the chemically precipitated Cu2S and Cu1.84Se powders have a stable elemental composition up to 200–240°C. An intense oxidation of the samples begins at a temperature exceeding 250°C and is accompanied by a sharp decrease in their content of sulfur (selenium) and by an increase in the content of oxygen. 相似文献
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Russian Physics Journal - A detailed analysis of the phase trajectories of cosmological models based on classical and scalar fields near surfaces of zero effective energy has been carried out. A... 相似文献
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E. L. Gavrilova I. A. Krutov A. A. Valieva Kh. R. Khayarov A. I. Samigullina A. T. Gubaidullin N. I. Shatalova R. N. Burangulova O. G. Sinyashin 《Russian Journal of General Chemistry》2018,88(11):2269-2275
New phosphorylated 1,2,4-triazole-3-thiones have been synthesized, and the possibility of their N,Sfunctionalization has been demonstrated. The direction of alkylation of 1,2,4-triazole-3-thiones with ethyl acrylate has been shown to depend on the substituent on the N4 atom. 相似文献
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Mamedov V. A. Khafizova E. A. Gubaidullin A. T. Murtazina A. M. Adgamova D. I. Samigullina A. I. Litvinov I. A. 《Russian Chemical Bulletin》2011,60(2):368-372
A reaction of 3-(α-aminobenzyl)quinoxalin-2(1H)-one with ethyl acetoacetate in boiling acetic acid is accompanied by contraction of the pyrazine ring. A rearrangement involving
the fragment C(2)-C(3)-C(NH2)Ph of the quinoxaline system and the fragment C(2)-C(3) of ethyl acetoacetate yields 2-(4-ethoxycarbonyl-5-methyl-2-phenylpyrrol-3-yl)benzimidazole.
Possible pathways of this reaction are considered. 相似文献
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B. V. Slobodin L. L. Surat B. V. Shulgin A. N. Cherepanov A. V. Ishchenko R. F. Samigullina F. G. Neshov 《Russian Journal of Inorganic Chemistry》2009,54(10):1543-1550
Rhombohedral hexametavanadates K4Sr(VO3)6, K4Ba(VO3)6, Rb4 Ba(VO3)6, and Cs4Ba(VO3)6 melt incongruently in the temperature range of 491 to 600°C. Cooling of peritectic melts yields mixtures of compounds typical
of M2+O-M2+O-V2O5 systems, far from equilibrium and depending on the cooling kinetics. The vanadate Cs4Ba(VO3)6 undergoes reversible polymorphic transformation at 360°C. All compounds show broad-band luminescence with a maximum of the
luminescence spectrum at 490–590 nm with three types of excitation. The vanadates K4Sr(VO3)6 and Rb4Ba(VO3)6 show the highest luminescence intensity at room temperature. The latter is also most efficient at liquid nitrogen temperatures.
The luminescence spectra depend on the excitation of vanadates. Three hypotheses were put forward to interpret this finding.
The nature of luminescence is attributed to the relaxation of electronic excitation in [VO4]3− structural tetrahedra present in the vanadates. The performance characteristics of luminophores were determined. These luminophores
may be promising as X-ray luminescent screens, radioluminescence indicators, and light-emitting diode devices. 相似文献
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B. V. Slobodin L. L. Surat R. F. Samigullina 《Russian Journal of Inorganic Chemistry》2009,54(5):797-802
Formation and stability temperatures were determined for the three polymorphs of copper pyrovanadate. The low-temperature β phase is formed at 500°C and is stable from room temperature to 610°C. The intermediate phase is stable within 610–705°C. The high-temperature γ phase is stable within 710–780°C. The rates of γ → α and α → β phase transitions upon cooling differ considerably. α-Cu2V2O7 detected at room temperature upon cooling of a molten sample is metastable. 相似文献
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V. V. Yanilkin N. V. Nastapova R. R. Fazleeva G. R. Nasretdinova E. D. Sultanova A. Yu. Ziganshina A. T. Gubaidullin A. I. Samigullina V. G. Evtugin V. V. Vorobev Yu. N. Osin 《Russian Chemical Bulletin》2018,67(2):215-229
Efficient mediated electrosynthesis of nanocomposite Au@р(MVCA8+-co-St) (~6 nm), in which ultrasmall Au nanoparticles (Au-NP) were bound in nanocapsules of water-soluble nanoparticles of соpolymer р(MVCA8+-co-St) of tetraviologen calix[4]resorcinol (MVCA8+) with styrene (St), was accomplished by the reduction of AuI in aqueous medium. The quanti- tative reduction of AuI was carried out using the theoretically necessary amount of electricity and was not accompanied by the deposition of metal on the electrode. Radical cations of viologen units MV?+ of the molecule р(MVCA4?+-co-St) adsorbed on the electrode and π-dimers MV?+···MV?+ of π-polymers [р(MVCA4?+-co-St)] n deposited on the electrode act- ed as the reducing agents with respect to AuI. During electrolysis, the nanoparticles agglo- merated to 37—50 nm. The nanocomposite particles dispersed in ethanol had sizes of 72±16 nm and also contained Au-NP with sizes of 51±8 and 19±3 nm. The catalytic activity of the nanocomposite in the reduction of p-nitrophenol with sodium borohydride was demon- strated. A similar reduction of AgCl nanoparticles (~250 nm) led to the formation of silver nanoparticles with crystallite sizes in the range of 7—11 nm, the process was inefficient, however, even when using 250% of electricity, an incomplete reduction of AgCl was still observed. 相似文献