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1.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Вальков, Валерий Владимирович, Аксенов, Сергей Владимирович, Уланов Е. А.
Заглавие : Эффект Фано при туннелировании спин-поляризованного электрона через одиночную магнитную примесь
Место публикации : Физ. низких температур. - 2013. - Т. 39, Вып. 1. - С. 48-52
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2.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Беляев, Борис Афанасьевич, Волошин, Александр Сергеевич, Шабанов, Василий Филиппович
Заглавие : Исследование добротности резонанса примесной моды в микрополосковой модели одномерного фотонного кристалла
Место публикации : Доклады Академии наук. - 2005. - Т. 403, № 3. - С. 319-324. - ISSN 0869-5652
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3.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Zhandun V. S., Zamkova N. G., Zinenko V. I.
Заглавие : Effect of an Eu3+ impurity on the antiferrodistortion and ferroelectric instabilities in an EuTiO3 bulk crystal and thin films
Коллективы : Russian Foundation for Basic Research [12-02-00025-a], Russian Federation [NSh-924.2014.2]
Место публикации : J. Exp. Theor. Phys.: MAIK Nauka-Interperiodica / Springer, 2015. - Vol. 120, Is. 1. - P.103-109. - ISSN 1063, DOI 10.1134/S1063776115010070. - ISSN 10906509(eISSN)
Примечания : Cited References:21. - This work was supported by the Russian Foundation for Basic Research (project no. 12-02-00025-a) and the program Leading Scientific Schools of the President of the Russian Federation (project no. NSh-924.2014.2).
Предметные рубрики: PEROVSKITES
Аннотация: The existence of an antiferrodistortion transition in EuTiO3 is disputable, and this question needs to be answered. One of the possible causes is the presence of an Eu3+ impurity in a sample. A nonempirical polarizable ion model is used to study the effect of a trivalent Eu3+ ion impurity on the antiferrodistortion and ferroelectric instabilities of an EuTiO3 crystal in the bulk and the thin-film states. Lattice dynamics calculation shows that a bulk impurity-free EuTiO3 crystal has no unstable modes throughout the entire phase space volume. The addition of an Eu3+ impurity leads to a significant softening of the rotational mode, the distortion in which makes tetragonal phase I4/mcm (which is experimentally observed) energetically favorable. In going from the bulk crystal to the thin film, the vibration spectrum of the impurity-free film has unstable antiferrodistortion and rotational modes. The addition of an Eu3+ impurity enhances the antiferrodistortion instability, which fully or partly suppresses ferroelectricity.
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4.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Yurkin G. Yu., Patrin G. S., Yarikov S. A.
Заглавие : Magnetic Properties of Fe1-xCoxSi Single Crystals at Low Co Impurity Concentrations
Место публикации : J. Sib. Fed. Univ. Math. Phys. - 2019. - Vol. 12, Is. 6. - P.756-771. - ISSN 1997-1397, DOI 10.17516/1997-1397-2019-12-1-1-6; Журн. СФУ. Матем. и физика. - ISSN 2313-6022 (eISSN)
Примечания : Cited References: 17
Аннотация: Velocity of bulk acoustic waves in base and rotated cuts have been measured by the ultrasonic pulse-echo method and values of CE ijkl and eijk in single crystals YAl3(BO3)4 have been calculated. The value of dijk piezoelectric modulus of these single crystals have been determined by quasistatic measurements, and εσ ij dielectric constants have been determined by the flat capacitor method. Experimental values of material constants have been applied for the study of Magnetostatic properties of FeSi and Fe0;98Co0;02Si single crystals have been studied. It has been found that the temperature and field dependences of the magnetization of monocrystal FeSi are strongly affected by introduction of a small amount of Co (2 %). A description of the results were provided by a model accounting for the formation of superparamagnetic iron clusters, as well as Fe-Co complexes. It is assumed that Fe-Co complexes form a ferromagnetic phase, which is approximately 0.6% of the Fe0;98Co0;02Si sample weightВ работе представлено исследование магнитостатических характеристик образцов FeSi и Fe0;98Co0;02Si. Обнаружено, что внесение небольшого количества примести Co (2 %) значительно влияет на температурные и полевые зависимости намагниченности монокристалла FeSi. Результаты обрабобтаны в рамках модели, учетывающей образование суперпарамагнитных кластеров железа, а также комплексов Fe-Co. Предполагается, что комплексы Fe-Co образуют ферромагнитную фазу, которая составляет примерно 0,6 % от массы образца Fe0;98Co0;02Si.
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5.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Yurkin G. Yu., Patrin G. S., Yarikov, Stanislav A.
Заглавие : Magnetic Properties of Fe1-xCoxSi Single Crystals at Low Co Impurity Concentrations
Место публикации : J. Sib. Fed. Univ. Math. Phys. - 2019. - Vol. 12, Is. 1. - P.94-99. - ISSN 1997-1397, DOI 10.17516/1997-1397-2019-12-1-94-99; \b Журнал СФУ. Математика и физика. - ISSN 2313-6022(eISSN)
Примечания : Cited References: 17
Ключевые слова (''Своб.индексиров.''): co impurities--iron silicide--superparamagnetism--силицид железа--примесь co--суперпарамагнетизм
Аннотация: Magnetostatic properties of FeSi and Fe0,98Co0,02Si single crystals have been studied. It has been found that the temperature and field dependences of the magnetization of monocrystal FeSi are strongly affected by introduction of a small amount of Co (2 %). A description of the results were provided by a model accounting for the formation of superparamagnetic iron clusters, as well as Fe-Co complexes. It is assumed that Fe-Co complexes form a ferromagnetic phase, which is approximately 0.6% of the Fe0,98Co0,02Si sample weight.В работе представлено исследование магнитостатических характеристик образцов FeSi и Fe0,98Co0,02Si. Обнаружено, что внесение небольшого количества примести Co(2%) значительно влияет на температурные и полевые зависимости намагниченности монокристалла FeSi. Результаты обработаны в рамках модели, учитывающей образование суперпарамагнитных кластеров железа, а также комплексов Fe-Co. Предполагается, что комплексы Fe-Co образуют ферромагнитную фазу, которая составляет примерно 0,6 % от массы образца Fe0,98Co0,02Si.
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6.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Vorotynov A. M., Ovchinnikov S. G., Rudenko V. V.
Заглавие : Uniaxial and basal plane anisotropy caused by Cr2+ impurity ions in CrBO3 crystals
Место публикации : J. Phys. Chem. Solids. - 2018. - Vol. 123. - P.389-392. - ISSN 00223697 (ISSN), DOI 10.1016/j.jpcs.2018.08.016
Примечания : Cited References: 14
Ключевые слова (''Своб.индексиров.''): anisotropy--chromium compounds--crystal impurities--ions--single crystals
Аннотация: IIn this study, the uniaxial and basal anisotropy governed by Cr2+ impurity ions was treated based on the Cr2+– BO3 3− ion vacancy model using single ion approximation. The anomalous behavior of the basal anisotropy at low temperatures was predicted.
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7.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Val'kov V. V., Aksenov S. V., Ulanov E. A.
Заглавие : Fano effect upon tunneling of a spin-polarized electron through a single magnetic impurity
Место публикации : Low Temp. Phys. - 2013. - Vol. 39, no. 1. - P.35-38. - DOI 10.1063/1.4775746; \b Физика низких температур
Аннотация: The calculations of transport characteristics of a single magnetic impurity showed that the presence of different effective channels for electron transmission results in the Fano effect. It was noticed that the external magnetic field and gate voltage allow controlling the conducting properties, which are governed by the configuration interaction between the states of the system
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8.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Val'kov V. V., Zlotnikov A. O.
Заглавие : Effect of pressure on antiferromagnetic and superconducting ordering in systems with heavy fermions
Коллективы : International Interdisciplinary Symposium “Ordering in Minerals and Alloys” (14th; 8 -13 Sept. 2011; Rostov-on-Don)
Место публикации : Bull. Russ. Acad. Sci.: Phys.: Allerton Press, 2012. - Vol. 76, Is. 7. - P.733-736. - ISSN 0022-2860, DOI 10.3103/S1062873812070362
Примечания : Cited References: 7. - This work was supported by the Department of Physical Sciences, Russian Academy of Sciences (the Strong Electron Correlations Program); the Russian Foundation for Basic Research, projects nos. 100200251 and 110200741; the RFBR Sibir’, project no. 110298007; and by the federal target program Scientific and Pedagogical Personnel of an Innovative Russia, 2009–2013.
Ключевые слова (''Своб.индексиров.''): antiferromagnetic orderings--antiferromagnetic orders--antiferromagnetic phasis--antiferromagnetics--cooper instability--effect of pressure--external pressures--heavy fermion--impurity level--localized state--periodic anderson model--seed energy--spin moments--superconducting ordering--superexchange interaction--superconductivity--antiferromagnetism
Аннотация: Characteristics of the superconducting and antiferromagnetic phases of heavy-fermion intermet-allides are described within a periodic Anderson model with allowance for the superexchange interaction between spin moments of the localized states. It is shown that an external pressure that changes the seed energy of an impurity level can rapidly destroy the long-range antiferromagnetic order. The development of the Cooper instability near such an order-disorder transition induces the experimentally observed state in which superconductivity coexists with the antiferromagnetic ordering. В© 2012 Allerton Press, Inc.
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9.

Вид документа : Статья из сборника (однотомник)
Шифр издания :
Автор(ы) : Val'kov V. V., Aksenov S. V., Ulanov E. A.
Заглавие : Effect of multiple scattering on the quantum transport of electrons through a magnetic impurity with a single-ion anisotropy : abstract
Коллективы : Российская академия наук, Физико-технический институт им. А.Ф. Иоффе РАН, "Spin Waves", International Symposium
Место публикации : Spin Waves 2013, Int. Symp.: Program. Abstracts. - СПб., 2013. - P.75. - ISBN 978-5-91918-334-1
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10.

Вид документа : Статья из сборника (однотомник)
Шифр издания :
Автор(ы) : Val'kov V. V., Aksenov S. V., Ulanov E. A.
Заглавие : Effect of multiple scattering on the quantum transport of electrons through a magnetic impurity with a single-ion anisotropy : abstract
Коллективы : "Functional Materials", International Conference , Taurida National V. I. Vernadsky University
Место публикации : Functional materials: Abstracts/ ed. V. N. Berzhansky. - Simferopol, 2013. - Ст.BP2-1P/2. - P. - ISBN 978-966-491-465-6
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11.

Вид документа : Статья из сборника (однотомник)
Шифр издания :
Автор(ы) : Boldyrev K. N., Popova M. N., Bezmaternykh L. N., Gudim, I. A.
Заглавие : Uncontrolled impurity of Bi3+ in rare-earth iron borates RFe3(BO3)4
Коллективы : International Conference on the Physics of Optical Materials and Devices
Место публикации : The 4th International Conference on the Physics of Optical Materials and Devices. ICOM 2015: book of abstracts. - 2015. - P.262. - ISBN 978-86-7306-134-4
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12.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Onufrienok V. V., Chzhan A. V., Bondarenko G. V., Yurkin G. Yu.
Заглавие : Transition of metastable pyrrhotites to a stable phase state
Место публикации : Inorg. Mater. - 2020. - Vol. 56, Is. 9. - P.898-902. - ISSN 0020-1685, DOI 10.1134/S0020168520090137. - ISSN 1608-3172(eISSN)
Примечания : Cited References: 23
Предметные рубрики: MAGNETIC-PROPERTIES
TEMPERATURE
CHEMISTRY
Аннотация: Equilibrium phase relations of synthetic minerals prepared by annealing metastable iron sulfides, followed by prolonged isothermal storage in the Earth atmosphere, have been studied by X-ray diffraction. The results demonstrate that prolonged storage of synthetic pyrrhotites annealed at different temperatures makes it possible to identify metastable and stable phases of Fe and S compounds.
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13.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Togushova, Yu. N., Shestakov V. A., Korshunov M. M.
Заглавие : Impurity-induced smearing of the spin resonance peak in Fe-based superconductors
Коллективы : RFBR [13-02-01395]; President Grant for Government Support of the Leading Scientific Schools of the Russian Federation [NSh-2886.2014.2]; Ministry of education and science of Russia [GF-2, SFU]
Место публикации : J. Low Temp. Phys.: Springer/Plenum Publishers, 2016. - Vol. 185, Is. 5-6. - P.481-487. - ISSN 0022-2291, DOI 10.1007/s10909-016-1577-x. - ISSN 1573-7357(eISSN)
Примечания : Cited References:25. - We acknowledge partial support by the RFBR (Grant 13-02-01395), President Grant for Government Support of the Leading Scientific Schools of the Russian Federation (NSh-2886.2014.2), and The Ministry of education and science of Russia (GF-2, SFU).
Предметные рубрики: HIGH-TEMPERATURE SUPERCONDUCTIVITY
ELECTRONIC-STRUCTURE
IRON
Ключевые слова (''Своб.индексиров.''): fe-based superconductors--spin resonance peak--spin-orbit coupling--impurity scattering
Аннотация: The spin resonance peak in the iron-based superconductors is observed in inelastic neutron scattering experiments and agrees well with predicted results for the extended s-wave (s±) gap symmetry. On the basis of four-band and three-orbital tight-binding models we study the effect of nonmagnetic disorder on the resonance peak. Spin susceptibility is calculated in the random-phase approximation with the renormalization of the quasiparticle self-energy due to the impurity scattering in the static Born approximation. We find that the spin resonance becomes broader with the increase of disorder and its energy shifts to higher frequencies. For the same amount of disorder the spin response in the s± state is still distinct from that of the s++ state.
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14.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Bondarenko G. V., Ovchinnikov S. G., Rudenko V. V., Sosnin V. M., Tugarinov V. I., Vorotynov A. M.
Заглавие : The generalized method of quantitative description of the uniaxial anisotropy in weak ferromagnet rhombohedral calcite type structure crystals with S-state ions
Место публикации : J. Magn. Magn. Mater. - 2013. - Vol. 335. - P.90-96. - ISSN 0304-8853, DOI 10.1016/j.jmmm.2013.01.037
Примечания : Cited References: 35
Ключевые слова (''Своб.индексиров.''): weak ferromagnetism--magnetic anisotropy--impurity
Аннотация: The method for investigation of the uniaxial and hexagonal anisotropies in weakly ferromagnetic rhombohedral FeBO3 crystals with the Fe2þ magnetic impurity with the use of the single-ion and pair approximation has been developed. In the framework of this method, a quantitative discrepancy between theoretical and experimental data on a uniaxial field has been eliminated. The energy contributions to the hexagonal anisotropy that are caused by the Dzyaloshinsky–Moriya interaction, the crystal field of Fe3þ ions and the temperature dependence of this anisotropy were analytically treated. The experimental temperature dependence of the hexagonal anisotropy of FeBO3 crystals is explained. It is shown that the compensation point and the typical temperature dependence of the hexagonal anisotropy result from the competition of the contributions of Fe3þ and Fe2þ ions. It is shown that respective considerable contributions to the anisotropy of Fe3þ and Fe2þ ions are made by the cubic symmetry and the uniaxial symmetry of the exchange ‘‘single-ion’’ type. The anisotropy constants for FeBO3 crystal was obtained by using the described results. It was shown, that for the calcite type structure crystals (iron borate and manganese carbonate) with S-state ions, the single ion and pair models (which previously raised doubts in their validity and accuracy) describe the experimental data good enough.
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15.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Shestakov V. A., Korshunov M. M., Dolgov O. V.
Заглавие : Temperature-dependent s± ↔ s++ transitions in the multiband model for Fe-based superconductors with impurities
Коллективы : Russian Foundation for Basic Research [16-02-00098]; Presidium of RAS Program for the Fundamental Studies [12]; "BASIS" Foundation for Development of Theoretical Physics and Mathematics; Gosbudget program [0356-2017-0030]
Место публикации : Symmetry. - Basel, 2018. - Vol. 10, Is. 8. - Ст.323. - ISSN 2073-8994, DOI 10.3390/sym10080323
Примечания : Cited References: 50. - This work was supported in part by the Russian Foundation for Basic Research (grant 16-02-00098), Presidium of RAS Program for the Fundamental Studies #12, and "BASIS" Foundation for Development of Theoretical Physics and Mathematics. MMK acknowledges support by the Gosbudget program #0356-2017-0030.
Предметные рубрики: IRON-BASED MATERIALS
Ключевые слова (''Своб.индексиров.''): unconventional superconductors--iron pnictides--iron chalcogenides--impurity scattering
Аннотация: We study the dependence of the superconducting gaps on both the disorder and the temperature within the two-band model for iron-based materials. In the clean limit, the system is in the s± state with sign-changing gaps. Scattering by nonmagnetic impurities leads to the change of the sign of the smaller gap, resulting in a transition from the s± to the s++ state with the sign-preserving gaps. We show here that the transition is temperature-dependent. Thus, there is a line of s±→s++ transition in the temperature–disorder phase diagram. There is a narrow range of impurity scattering rates, where the disorder-induced s±→s++ transition occurs at low temperatures, but then the low-temperature s++ state transforms back to the s± state at higher temperatures. With increasing impurity scattering rate, the temperature of such s++→s± transition shifts to the critical temperature Tc, and only the s++ state is left for higher amounts of disorder.
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16.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Shestakov V. A., Korshunov M. M.
Заглавие : Influence of temperature on the impurity-induced s ± → s ++ transition in the two-band model for Fe-based superconductors
Коллективы : Euro-Asian Symposium "Trends in MAGnetism"
Место публикации : J. Phys. Conf. Ser. - 2019. - Vol. 1389, Is. 1. - Ст.012065. - ISSN 1742-6588, DOI 10.1088/1742-6596/1389/1/012065. - ISSN 1742-6596 (eISSN)
Примечания : Cited References: 45. - The reported study was funded by RFBR, project number 19-32-90109, and by the “BASIS” Foundation for Development of Theoretical Physics and Mathematics.
Аннотация: In Fe-based superconducting materials, the s ± state with the sign-changing gap in the clean limit could be changed to the sign-conserving s ++ state by nonmagnetic impurities. Previous results are obtained for the fixed temperature well below the superconducting critical temperature Tc . We study how the increasing temperature affects the transition between s ± and s ++ states in the two-band model. The calculations show that the s ± → s ++ transition appears to be dependent on temperature T, i.e. there exists a narrow range of impurity scattering rates, where the s ++ state in dirty superconductor at low temperature is transformed back to the s ± state by increasing T. With the nonmagnetic impurity scattering rate increasing, the temperature of such a reverse transition is shifted to Tc , while the s ++ state remains solely one for higher degree of disorder.
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17.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : SANDALOV I. S., YERUKHIMOV M. S.
Заглавие : EFFECT OF MIXING THE STATES OF CONDUCTIVITY ELECTRONS AND IMPURITY D(F) IONS ON ELECTRIC-CONDUCTIVITY
Место публикации : Zhurnal Eksperimentalnoi Teor. Fiz.: MEZHDUNARODNAYA KNIGA, 1982. - Vol. 82, Is. 1. - P246-253. - ISSN 0044-4510
Примечания : Cited References: 17
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18.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Klyuchantsev A. B., Dzebisashvili D. M.
Заглавие : Quantum transport via dot devices with arbitrarily strong interactions
Колич.характеристики :22 с
Место публикации : Phys. Scr. - 2023. - Vol. 98, Is. 3. - Ст.035811. - ISSN 00318949 (ISSN), DOI 10.1088/1402-4896/acb61e. - ISSN 14024896 (eISSN)
Примечания : Cited References: 49. - The authors would like to thank V V Val'kov and S.V. Aksenov for fruitful discussions
Аннотация: The paper develops a theory of tunneling electron transport through atomic-scale systems (or briefly quantum dots) with arbitrarily strong interaction. The theory is based on a diagram technique for nonequilibrium Green’s functions defined on Hubbard operators. The use of Hubbard operators, describing many-body states of an entire quantum dot, makes it possible to represent the Hamiltonian of the quantum dot in a universal diagonal form and consider its coupling with two leads within the perturbation theory. It is shown that in the case when all Hubbard operators are defined for the same site, some rules of the diagram technique for Hubbard operators, initially developed for lattice models, have to be modified. As an example of the application of the modified theory, the current-voltage characteristics of the single-impurity Anderson model with infinitely large Coulomb repulsion are calculated. It is shown that taking into account the multiple electron tunneling processes with spin flips results in the dip in the center of the Lorentz distribution peak, describing the density of states of the one level Anderson impurity coupled with two leads. The emergence of this dip in the density of states leads to a peculiar feature in the bias voltage dependence of the differential conductivity, which can be detected experimentally.
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19.

Вид документа : Статья из сборника (однотомник)
Шифр издания :
Автор(ы) : Chzhan A.V., Patrin G.S., Isaeva I.N.
Заглавие : Photo-induced Relaxation Self-Oscillations of Stripe Structures in FeBO(3)
Место публикации : DEFECTS AND DIFFUSION IN METALS: AN ANNUAL RETROSPECTIVE XI. - STAFA-ZURICH: TRANS TECH PUBLICATIONS LTD, 2009. - Vol. 293. - С. 115-119. - (Defect and Diffusion Forum Series). - ISBN 1012-0386
Примечания : Cited Reference Count: 6
Ключевые слова (''Своб.индексиров.''): impurity centers--induced magnetic anisotropy--iron borate--relaxation
Аннотация: Photo-induced self-oscillations of stripe structures are studied in FeBO(3) crystals at low temperatures. Experimental data show that the observed oscillations have a relaxational character. On the basis of the research carried out, a model for such oscillations is presented.
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20.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Petrakovsky G. A., Patrin G. S.
Заглавие : Effect of optical-excitation of impurity holmium ions on magnetic-resonance in yttrium-iron-garnet
Место публикации : Zhurnal Eksperimentalnoi Teor. Fiz.: MEZHDUNARODNAYA KNIGA, 1986. - Vol. 90, Is. 5. - P1769-1780. - ISSN 0044-4510
Примечания : Cited References: 27
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