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Каталог книг и брошюр библиотеки ИФ СО РАН

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Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Mikhaleva E. A., Gorev M. V., Molokeev M. S., Kartashev A. V., Flerov I. N.
Заглавие : Anisotropy of piezocaloric effect at ferroelectric phase transitions in ammonium hydrogen sulphate
Место публикации : J. Alloys Compd. - 2020. - Vol. 839. - Ст.155085. - ISSN 09258388 (ISSN), DOI 10.1016/j.jallcom.2020.155085
Примечания : Cited References: 31. - The reported study was supported by the Russian Science Foundation (project no. 19-72-00023 ). X-ray and dilatometric data were obtained using the equipment of Krasnoyarsk Regional Center of Research Equipment of Federal Research Center "Krasnoyarsk Science Center SB RAS"
Аннотация: The role of anisotropy of the thermal expansion in formation of piezocaloric effect (PCE) near ferroelectric phase transitions in NH4HSO4 was studied. Strong difference in linear baric coefficients and as a result in intensive and extensive PCE associated with the different crystallographic axes was found. PCE giving the main contribution to the barocaloric effect were determined at both phase transitions. Rather strong effect of the lattice dilatation on the tuning of PCE was observed. Comparative analysis of PCE at the phase transitions in different materials showed that NH4HSO4 can be considered as a promising solid-state refrigerant. A hypothetical cooling cycle based on alternate using uniaxial pressure along two axes was considered.
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Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Bogdanov E. V., Kartashev A. V., Pogoreltsev E. I., Gorev M. V., Laptash N. M., Flerov I. N.
Заглавие : Anomalous behaviour of thermodynamic properties at successive phase transitions in (NH4)3GeF7
Место публикации : J. Solid State Chem. - 2017. - Vol. 256. - P.162-167. - ISSN 00224596 (ISSN), DOI 10.1016/j.jssc.2017.09.010
Примечания : Cited References: 23. - The reported study was partially supported by the Russian Foundation for Basic Research, research project no. 15-02-02009 a.
Ключевые слова (''Своб.индексиров.''): phase transition--fluorides--heat capacity--entropy--thermal expansion--high pressure
Аннотация: Heat capacity, thermal dilatation, susceptibility to hydrostatic pressure and dielectric properties associated with succession of three phase transitions below room temperature in double fluoride salt (NH4)3GeF7 were studied. A possible transformation into the parent Pm-3m cubic phase was not observed up to the decomposition of compound. Nonferroelectric nature of structural distortions was confirmed. The DTA under pressure studies revealed a high temperature stability of two phases: P4/mbm and Pbam. The entropies of the phase transitions agree well with the model of structural distortions. Analysis of the thermal properties associated with the individual phase transitions in the framework of thermodynamic equations has shown a high reliability of the data obtained. © 2017 Elsevier Inc.
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Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Gorev M. V., Kartashev A. V., Bogdanov E. V., Flerov I. N., Laptash N. M.
Заглавие : Calorimetric, dilatometric and DTA under pressure studies of the phase transitions in elpasolite (NH4)2KZrF7
Место публикации : J. Fluor. Chem. - 2020. - Vol. 235. - Ст.109523. - ISSN 00221139 (ISSN), DOI 10.1016/j.jfluchem.2020.109523
Примечания : Cited References: 45. - The reported study was funded by RFBR according to the research project No. 18-02-00269 a. X-ray and dilatometric data were obtained using the equipment of Krasnoyarsk Regional Center of Research Equipment of Federal Research Center "Krasnoyarsk Science Center SB RAS"
Аннотация: Heat capacity, thermal expansion, and sensitivity to the hydrostatic pressure of (NH4)2KZrF7 elpasolite are studied in a wide temperature range. The changes in deformation and entropy during successive phase transitions are determined: Δ(ΔV/V) = 3·10−4; ΔS = 8 J/mol K The temperatures and entropies of phase transitions turned out to be slightly sensitive to pressure changes. An analysis of the entropy of phase transformations was performed in the framework of the model of the cubic phase structure Fm-3 m. In the low temperature phase, an anomalous behavior of thermodynamic properties, which is not characteristic of phase transitions, was observed, accompanied by a significant change in the crystal lattice entropy.
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Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Flerov I. N., Gorev M. V., Bogdanov E. V., Laptash N. M.
Заглавие : Chemical pressure as an effective tool for tuning the structural disordering and barocaloric efficiency of complex fluorides (NH4)3MF7 (M: Sn, Ti, Ge, Si)
Колич.характеристики :18 с
Место публикации : J. Phys. D: Appl. Phys. - 2024. - Vol. 57, Is. 17. - Ст.175301. - ISSN 00223727 (ISSN), DOI 10.1088/1361-6463/ad211b. - ISSN 13616463 (eISSN)
Примечания : Cited References: 39. - The study was supported by a Grant from the Russian Science Foundation No. 23-22-00115, https://rscf.ru/project/23-22-00115/
Аннотация: Double fluoride salts (NH4)3M4+F7 (M4+: Sn, Ti, Ge, Si) demonstrate a high efficiency of using chemical pressure as a tool for control and tuning structural ordering/disordering, sensitivity to hydrostatic pressure, successions of the phase transitions, etc and, as a result, for purposeful variation within a wide range of parameters of barocaloric effect (BCE). The conventional and inverse BCEs near the triple points were found on the T − p phase diagrams, combination of which can be used to construct original cooling cycle in narrow temperature and pressure ranges. Reconstructive transformation between two cubic phases, Pm3-m ↔ Pa3-, realized in (NH4)3SnF7 at atmospheric pressure and in (NH4)3TiF7 at p ˃ 0.4 GPa are characterized by rather low thermal hysteresis, δT0 = 1 K, and a great entropy change, ΔSBCE = 110–152 J (kg · K)−1, depending on the size of the central atom. At above 300–350 K, a contribution to BCE associated with the regular thermal expansion of the crystal lattice becomes comparable to entropy and temperature changes under pressure in the region of the phase transitions. An analysis of the absolute, relative and integral barocaloric characteristics of (NH4)3M4+F7 compounds showed their high competitiveness with respect to other barocaloric materials considered as promising solid-state refrigerants.
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Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Gorban A., Popova T., Zinovyev A.
Заглавие : Codon usage trajectories and 7-cluster structure of 143 complete bacterial genornic sequences
Разночтения заглавия :авие SCOPUS: Codon usage trajectories and 7-cluster structure of 143 complete bacterial genomic sequences
Место публикации : Physica A: ELSEVIER SCIENCE BV, 2005. - Vol. 353. - P365-387. - ISSN 0378-4371, DOI 10.1016/j.physa.2005.01.043
Примечания : Cited References: 46
Предметные рубрики: DNA-BASE COMPOSITION
ASYMMETRIC SUBSTITUTION PATTERNS
PROTEIN-CODING REGIONS
MICROBIAL GENOMES
GENE IDENTIFICATION
MARKOV-MODELS
G+C CONTENT
BIAS
PREDICTION
SELECTION
Ключевые слова (''Своб.индексиров.''): genome--cluster--codon usage--correlations--entropy--mean field--cluster--codon usage--correlations--entropy--genome--mean field--approximation theory--correlation methods--database systems--entropy--functions--genes--mathematical models--clusters--codon usage--genomes--mean field--bacteria
Аннотация: Three results are presented. First, we prove the existence of a universal 7-cluster structure in all 143 completely sequenced bacterial genomes available in Genbank in August 2004, and explained its properties. The 7-cluster structure is responsible for the main part of sequence heterogeneity in bacterial genomes. In this sense, our 7 clusters is the basic model of bacterial genome sequence. We demonstrated that there are four basic "pure" types of this model, observed in nature: "parallel triangles", "perpendicular triangles", degenerated case and the flower-like type. Second, we answered the question: how big are the position-specific information and the contribution connected with correlations between nucleotide. The accuracy of the mean-field (context-free) approximation is estimated for bacterial genomes. We show that codon us-age of bacterial genomes is a multi-linear function of their genomic G+C-content with high accuracy (more precisely, by two similar functions, one for eubacterial genomes and the other one for archaea). Description of these two codon-usage trajectories is the third result. All 143 cluster animated 3D-scatters are collected in a database and is made available on our web-site: http://www.ihes.fr/similar to zinovyev/7clusters. (c) 2005 Elsevier B.V. All rights reserved.
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Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Mikhaleva E. A., Gorev M. V., Bondarev V. S., Bogdanov E. V., Flerov I. N.
Заглавие : Comparative analysis of elastocaloric and barocaloric effects in single-crystal and ceramic ferroelectric (NH4)2SO4
Место публикации : Scripta Mater. - 2021. - Vol. 191. - P.149-154. - ISSN 13596462 (ISSN), DOI 10.1016/j.scriptamat.2020.09.030
Примечания : Cited References: 47. - The reported study was supported by the Russian Science Foundation (project no. 19-72-00023 ). X-ray and dilatometric data were obtained using the equipment of Krasnoyarsk Regional Center of Research Equipment of Federal Research Center “Krasnoyarsk Science Center SB RAS”
Аннотация: We report the influence of anisotropy and texture on elasto(ElCE)- and baro(BCE)-caloric effects in single-crystal and ceramic (NH4)2SO4. Inverse extensive and intensive ElCE in ceramics, (ΔSElCE)cer = 87 J/kg·K; ΔTAD = - 11.6 K), as well as in a single crystal along the ferroelectric axis a, (ΔSElCE)a = 115 J/kg·K; (ΔTAD)a = - 16 K, significantly exceed BCE, ΔSBCE = 75 J/kg·K; ΔTAD = - 9.8 K, even at low pressure ~ 0.3 GPa. Caloric parameters of ammonium sulphate are comparable with those for promising solid-state refrigerants.
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Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Gorev M. V., Bogdanov E. V., Flerov I. N.
Заглавие : Conventional and inverse barocaloric effects around triple points in ferroelastics (NH4)3NbOF6 and (NH4)3TiOF5
Место публикации : Scripta Mater. - 2017. - Vol. 139. - P.53-57. - ISSN 13596462 (ISSN), DOI 10.1016/j.scriptamat.2017.06.022
Примечания : Cited References: 17
Ключевые слова (''Своб.индексиров.''): barocaloric effect--entropy--order-disorder phenomena--phase diagram--polymorphic phase transformation
Аннотация: We report the conventional and inverse barocaloric effect (BCE) in ferroelastics (NH4)3NbOF6 and (NH4)3TiOF5. We found a rich set of the structural phase transitions and triple points on the T − p phase diagrams. Extensive and intensive BCE near some transformations and around triple points in both crystals are outstanding (|∆ SBCE max | = 30–100 J/kg·K; |∆ TAD max | = 4–22 K) and can be achieved at low pressure 0.01–0.60 GPa.
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Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Gorev M. V., Mikhaleva E. A., Flerov I. N., Bogdanov E. V.
Заглавие : Conventional and inverse barocaloric effects in ferroelectric NH4HSO4
Место публикации : J. Alloys Compd. - 2019. - Vol. 806. - P.1047-1051. - ISSN 09258388 (ISSN), DOI 10.1016/j.jallcom.2019.07.273
Примечания : Cited References: 22
Аннотация: In this study, the conventional and inverse barocaloric effects (BCE) in ferroelectric NH4HSO4 are reported. Maximum extensive and intensive BCE near order–disorder phase transition can be achieved at low pressure p≤0.1 GPa. Large thermal expansion of the crystal lattice plays a very important role in the developing conventional BCE and conversation between BCE of different sign in the narrow temperature range.
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Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Bondarev V. S., Mikhaleva E. A., Gorev M. V., Flerov I. N.
Заглавие : Direct and indirect studies of the electrocaloric effect in single crystalline ferrielectric (NH4)2SO4
Место публикации : J. Alloys Compd. - 2022. - Vol. 892. - Ст.162130. - ISSN 09258388 (ISSN), DOI 10.1016/j.jallcom.2021.162130
Примечания : Cited References: 38. - The reported study was supported by the Russian Science Foundation (project no. 19-72-00023)
Аннотация: The influence of an electric field on the phase transition parameters and the electrocaloric response in ferrielectric (NH4)2SO4 was studied using a universal multifunctional adiabatic calorimeter. The very low sensitivity of the phase transition temperature to the electric field, dT0/dE ≈ 5·10-3 K/(kV/cm), was shown to be the reason for the low maximum value of the intensive electrocaloric effect, ΔTAD, at E = 11 kV/cm: direct and indirect measurements gave the values of 0.01 K and 0.05 K, respectively. However, the extensive electrocaloric response revealed by an analysis of the entropy–temperature–electric field phase diagram was relatively large, with a value of ΔSECE ≈ − 19 J/kg K, due to the significant contribution of a jump in the excess entropy to the total value, δS0/ΔS0 ~ 0.37. An additional irreversible increase in temperature under the electric field was associated with the Joule effect and indicated a significant electrical conductivity of ammonium sulphate.
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10.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Flerov I. N., Gorev M. V., Fokina V. D., Bovina A. F., Bogdanov E. V., Pogoreltsev E. I., Laptash N. M.
Заглавие : Disorder and phase transitions in oxyfluoride (NH4)(3)Ta(O-2)(2)F-4
Место публикации : J. Fluor. Chem. - 2011. - Vol. 132, Is. 10. - P.713-718. - ISSN 0022-1139, DOI 10.1016/j.jfluchem.2011.05.012
Примечания : Cited Reference Count: 19. - Гранты: This work was supported by the Council on Grants from the President of the Russian Federation for the Support of Leading Scientific Schools of the Russian Federation (NSh-4645.2010.2).Финансирующая организация: Council on Grants from the President of the Russian Federation for the Support of Leading Scientific Schools of the Russian Federation [NSh-4645.2010.2]
Предметные рубрики: HEAT-CAPACITY
COMPLEXES
RB2KTIOF5
FLUORIDES
CRYOLITE
Ключевые слова (''Своб.индексиров.''): cubic oxyfluorides--structural disorder--phase transitions--entropy--permittivity--pressure effect--cubic oxyfluorides--entropy--permittivity--phase transitions--pressure effect--structural disorder
Аннотация: Calorimetric, X-ray, dielectric and DTA under pressure measurements have been performed on oxyfluoride (NH4)(3)Ta(O-2)(2)F-4. The succession of nonferroelectric phase transitions was found associated with the order-disorder processes. The comparative analysis tantalate with related niobate has revealed the important role of the central atom in the physical properties behavior, mechanism of structural distortions and barocaloric effect in oxyfluorides with the eight-coordinated anionic polyhedra. (C) 2011 Elsevier By. All rights reserved.
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