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61.
V. E. Smirnova E. N. Popova V. M. Svetlichnyi L. A. Myagkova A. N. Orekhov V. E. Yudin A. M. Muzafarov E. A. Tatarinova 《Russian Journal of Applied Chemistry》2011,84(10):1800-1804
The effect exerted by thermal aging in air at 350°C on the thermal and mechanical properties of composite films prepared on
the basis of heat-resistant polyimide PM and non-film-forming polymethylphenylsiloxane (PMPS) was examined. The phase segregation
of polymeric composites of various compositions and the thermal aging rate were evaluated. 相似文献
62.
N. N. Smirnova Yu. A. Zakharova A. V. Markin N. V. Kuchkina E. Yu. Yuzik-Klimova Z. B. Shifrina 《Russian Chemical Bulletin》2013,62(10):2258-2262
The temperature dependences of heat capacity C ○ p = f(T) of hard poly(phenylene-pyridyl) dendrimers of the first and the second generations based on 1,3,5-triethynylbenzene were studied over the temperature range from 7–180 to 455–470 K for the first time. Over the range 290–350 K, the relaxation transition supposedly caused by sample devitrification was detected and characterized for the dendrimer of the first generation. The experimental results were used to calculate the standard thermodynamic functions, namely, heat capacity, enthalpy, entropy, and change in the Gibbs energy on heating. The standard entropy of formation of the compounds under study was determined at T = 298.15 K. The qualitative and quantitative dependences of the thermodynamic properties of the poly(phenylene-pyridyl) dendrimers on their composition and structure were revealed by comparison of the determined parameters with similar data for the earlier studied dendrimers of this series. 相似文献
63.
Natalya N. Smirnova Tatiana G. Kulagina Larisa A. Smirnova Alla E. Mochalova Lyudmila Ya. Tsvetkova Ya. S. Samosudova Maksim B. Kiseliov Evgeny V. Sevast’yanov 《Journal of Thermal Analysis and Calorimetry》2013,112(3):1447-1452
For the first time, the heat capacity $ C_{\text{p}}^{^\circ } $ of poly(2-ethylhexyl acrylate) has been studied in an adiabatic vacuum calorimeter between 7 and 350 K, the standard thermodynamic functions: heat capacity $ C_{\text{p}}^{^\circ } $ (T), enthalpy H°(T) ? H°(0), entropy S°(T) ? S°(0), Gibbs function G°(T) ? H°(0) have been calculated from T → 0 to 350 K. The energy of combustion Δc U of the compound under study has been measured in a calorimeter with a stationary bomb and an isothermal shell. The standard enthalpy of combustion Δc H° and thermodynamic parameters of formation—enthalpy Δf H°, entropy Δf S°, Gibbs function Δf G°—at T = 298.15 K have been calculated. The results have been used to calculate the thermodynamic characteristics of 2-ethylhexyl acrylate bulk polymerization into poly(2-ethylhexyl acrylate) over the range from T → 0 to 350 K. 相似文献
64.
V. I. Pet’kov E. A. Asabina M. V. Sukhanov A. V. Markin N. N. Smirnova 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2013,87(12):1960-1968
The temperature dependence of the heat capacity C p ○ = f(T) of CaNi0.5Zr1.5(PO4)3 crystalline phosphate is studied by precision adiabatic vacuum and differential scanning calorimetry over the temperature range of 7–640 K. Its standard thermodynamic functions C p ○ (T), H ○(T)-H ○(0), S ○(T), and G ○(T)-H ○(0) for the region T → 0 to 640 K and the standard entropy of formation at T = 298.15 K are calculated from the obtained experimental data. Using data on the low-temperature (30–50 K) heat capacity, the D fractal dimension of phosphate is determined and conclusions about the character of the topology of its structure have been made. The final results are compared to data from thermodynamic investigations of the structurally related crystalline phosphates Zr3(PO4)4, Ni0.5Zr2(PO4)3, and Ca0.5Zr2(PO4)3. 相似文献
65.
D. N. Chausov А. D. Kurilov А. V. Kazak А. I. Smirnova V. К. Velichko E. V. Gevorkyan 《Liquid crystals》2013,40(9):1345-1352
A cholesteric liquid crystal (CLC) – cholesteryl tridecylate (X-20) was doped with nanoparticles of shungite carbon (Sh) to effectively improve some physicochemical properties of the CLC matrix for the further use in electronic devices. The influence of Sh (concentration of 0.005 and 0.02 wt. %) on phase transition temperatures of X-20 was studied. Addition of 0.005 wt. % of Sh shifts phase transition temperatures upward, while the concentration increase to 0.02 wt. % leads to the opposite effect. These data were taken into account during the study of dielectric properties in different phase states. The dielectric properties were studied in the frequency range from 20 Hz to 10 MHz. Only for the system X-20/Sh (0.02 wt. %), dispersion of the dielectric permittivity was observed. The dispersion was caused by the appearance of additional relaxation processes and it was substantially more extended than the classical Debye theory suggests. The results of the research show that the ‘CLC – Sh nanoparticles’ composites can be used as promising materials to increase the efficiency of radio electronics devices. 相似文献
66.
A. V. Kaznacheev I. Yu. Smirnova A. S. Sonin N. A. Churochkina 《Polymer Science Series A》2013,55(3):153-158
Samples of nematics stabilized by a polymer network, which are new composite materials, were prepared. A ZhK-1277 nematic composite and a bisphenyl-A-dimethacrylate monomer were used. Polymerization was conducted via UV radiation. The electro-optic properties, i.e., the dependence of transmittance and the turn-on and turn-off times on the electric voltage and layer thickness, of the resulting material and a pure nematic were studied. The experimental results are explained by the domain structure of the nematic in a polymer network, according to which the liquid crystal in an electro-optic cell is composed of oriented domains separated by thin partitions of the polymer. The size of the domain regions of the liquid crystal is 2 μm. 相似文献
67.
Ionic and Phase Compositions of Y2.5Ce0.5Fe2.5Ga2.5O12 Ferrogarnet Powder Produced by Gel Combustion
Teterin Yu. A. Smirnova M. N. Maslakov K. I. Teterin A. Yu. Kopeva M. A. Nikiforova G. E. Ketsko V. A. 《Doklady Physical Chemistry》2022,503(2):45-49
Doklady Physical Chemistry - The ionic and phase compositions of Y2.5Ce0.5Fe2.5Ga2.5O12 ferrogarnet samples obtained by gel combustion with subsequent vacuum annealing were studied for the first... 相似文献
68.
Eremina Julia A. Smirnova Ksenia S. Lider Elizaveta V. Klyushova Lyubov’ S. Sheven’ Dmitriy G. Potkin Vladimir I. 《Transition Metal Chemistry》2022,47(1):19-30
Transition Metal Chemistry - In this study, Ni(II) and Co(II) complexes [Co(H2O)2L2] (1), [Ni(H2O)2L2] (2), [Co(phen)L2] (3), [Ni(phen)L2]·2H2O·EtOH (4·2H2O), and... 相似文献
69.
V. S. Krivobok I. A. Denisov E. N. Mozhevitina S. N. Nikolaev E. E. Onishchenko A. A. Pruchkina A. A. Silina N. A. Smirnova M. A. Chernopitsskii N. I. Shmatov 《Physics of the Solid State》2016,58(5):981-991
Shallow impurity–defect states in undoped Cd1–xZnxTe (x ~ 3–6%) single crystals have been studied using low-temperature photoluminescence measurements. It has been found that the effect exerted by zinc is mainly reduced to a rigid shift of all the specific features associated with the exciton radiation, which made it possible, with a high (~0.3 meV) accuracy, to measure the band gap and the zinc concentration in solid solutions. Hydrogen-like donors with the ground-state energy of ~14 meV and four types of acceptors with average activation energies of 59.3 ± 0.6 meV, 69.6 ± 1.5 meV, 155.8 ± 2.0 meV, and 52.3 ± 0.6 meV have been identified in all the crystals studied. Based on a comparison with the results of the analysis of the impurity background and the data available in the literature on impurity–defect emission in undoped CdTe, the first three acceptors can be assigned to the substitutional impurities NaCd, PTe, and CuCd, respectively. The most shallow acceptor (52.3 ± 0.6 meV) is a complex defect in which there is a nonstandard excited level separated by only 7 meV from the ground level. This level is formed apparently due to the removal of degeneracy, which is characteristic of TD acceptors, by the low-symmetry potential of the complex defect. 相似文献
70.
Smirnova M. N. Kop’eva M. A. Nikiforova G. E. Nipan G. D. Yapryntsev A. D. Petrova K. V. Korotkova N. A. 《Doklady Chemistry》2021,500(2):213-218
Doklady Chemistry - The boundaries of Mg1 – xNixGa2O4 solid solutions (0 ≤ х ≤ 0.5) with a spinel structure synthesized by the gel combustion method,... 相似文献