Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

Wyszukujesz frazę "Bykov, V. I" wg kryterium: Wszystkie pola


Wyświetlanie 1-4 z 4
Tytuł:
Size Effects in Radiospectroscopy Spectra of Ferroelectric Nanopowders
Autorzy:
Glinchuk, M. D.
Kondakova, I. V.
Laguta, V. V.
Slipenyuk, A. M.
Bykov, I. P.
Ragulya, A. V.
Klimenko, V. P.
Powiązania:
https://bibliotekanauki.pl/articles/2043389.pdf
Data publikacji:
2005-07
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
73.22.-f
61.72.Hh
68.35.Rh
Opis:
The theoretical and experimental investigation of ferroelectric nanopowders is performed. The manifestation in radiospectroscopy spectra of size driven ferroelectric-paraelectric phase transition at some critical particle average size R = R$\text{}_{c}$ was the main goal of the consideration. In theoretical part the size effect for the materials with ferroelectric tetragonal phase at room temperature and cubic paraelectric phase was considered allowing for the spontaneous polarization inhomogeneity inside a particle and distribution of particle sizes. In ESR the transformation of the spectra from tetragonal symmetry to cubic symmetry lines with decrease in nanoparticle sizes was calculated. The method of R$\text{}_{c}$ value extraction from the ratio of the different symmetry lines intensities in the absorption spectra was proposed. Measurements of Fe$\text{}^{3+}$ ESR spectra in nanopowder of BaTiO$\text{}_{3}$ were carried out at room temperature. The samples were prepared by rate-controlled method with different particle sizes, which depend on annealing temperature. The decrease in intensity of tetragonal symmetry ESR lines of Fe$\text{}^{3+}$ and appearance of cubic symmetry line with asymmetry of the shoulders was observed with the average sizes decrease with complete disappearance of tetragonal spectrum at R ≤ 40 nm. The comparison of the theory with experiment was carried out. The theory fits experimental data pretty good. The value of critical size R$\text{}_{c}$ ≈ 40 nm was extracted from ESR data. The asymmetry and broadening of right hand side shoulder of ESR cubic symmetry line was shown to be related to contribution of paramagnetic centers in the vicinity of the particles surface with lower than cubic symmetry. The deconvolution of the cubic line allowed to show that this region size is about 3 nm.
Źródło:
Acta Physica Polonica A; 2005, 108, 1; 47-60
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Local Order in KTaO$\text{}_{3}$ Admixtured by the Ions of Li$\text{}^{+}$
Autorzy:
Kaszyńska, K.
Trybuła, Z.
Glinchuk, M. D.
Bykov, I. P.
Laguta, V. V.
Powiązania:
https://bibliotekanauki.pl/articles/2043642.pdf
Data publikacji:
2005-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
64.70.-p
36.40.Ei
77.22.Gm
74.72.-h
74.76.Bz
Opis:
The low temperature behavior of the KTaO$\text{}_{3}$ type incipient ferroelectric crystals is of constant interest. The quantum fluctuations reduce the transition to the ferroelectric state in these crystals. It is possible that the small amount of the dopant Li$\text{}^{+}$ can lead, through the elastic interactions, to local glass-like short-range order or even to the relaxor ferroelectric order for x>2.6%. We presented that the low lithium doped x=0.005 KTaO$\text{}_{3}$ crystals exhibit the dielectric dispersion ofε andε", suggesting the glass-like behavior in the low temperature range.
Źródło:
Acta Physica Polonica A; 2005, 108, 2; 379-383
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
More About the Height of Faces in 3-Polytopes
Autorzy:
Borodin, Oleg V.
Bykov, Mikhail A.
Ivanova, Anna O.
Powiązania:
https://bibliotekanauki.pl/articles/31342325.pdf
Data publikacji:
2018-05-01
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
plane map
planar graph
3-polytope
structural properties
height of face
Opis:
The height of a face in a 3-polytope is the maximum degree of its incident vertices, and the height of a 3-polytope, h, is the minimum height of its faces. A face is pyramidal if it is either a 4-face incident with three 3-vertices, or a 3-face incident with two vertices of degree at most 4. If pyramidal faces are allowed, then h can be arbitrarily large, so we assume the absence of pyramidal faces in what follows. In 1940, Lebesgue proved that every quadrangulated 3-polytope has h ≤ 11. In 1995, this bound was lowered by Avgustinovich and Borodin to 10. Recently, Borodin and Ivanova improved it to the sharp bound 8. For plane triangulation without 4-vertices, Borodin (1992), confirming the Kotzig conjecture of 1979, proved that h ≤ 20, which bound is sharp. Later, Borodin (1998) proved that h ≤ 20 for all triangulated 3-polytopes. In 1996, Horňák and Jendrol’ proved for arbitrarily polytopes that h ≤ 23. Recently, Borodin and Ivanova obtained the sharp bounds 10 for trianglefree polytopes and 20 for arbitrary polytopes. In this paper we prove that any polytope has a face of degree at most 10 with height at most 20, where 10 and 20 are sharp.
Źródło:
Discussiones Mathematicae Graph Theory; 2018, 38, 2; 443-453
2083-5892
Pojawia się w:
Discussiones Mathematicae Graph Theory
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Low 5-Stars at 5-Vertices in 3-Polytopes with Minimum Degree 5 and No Vertices of Degree from 7 to 9
Autorzy:
Borodin, Oleg V.
Bykov, Mikhail A.
Ivanova, Anna O.
Powiązania:
https://bibliotekanauki.pl/articles/31348144.pdf
Data publikacji:
2020-11-01
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
planar map
planar graph
3-polytope
structural properties
5-star
weight
height
Opis:
In 1940, Lebesgue gave an approximate description of the neighborhoods of 5-vertices in the class $P_5$ of 3-polytopes with minimum degree 5. Given a 3-polytope $P$, by $h_5(P)$ we denote the minimum of the maximum degrees (height) of the neighborhoods of 5-vertices (minor 5-stars) in $P$. Recently, Borodin, Ivanova and Jensen showed that if a polytope $P$ in $P_5$ is allowed to have a 5-vertex adjacent to two 5-vertices and two more vertices of degree at most 6, called a (5, 5, 6, 6, ∞)-vertex, then $h_5(P)$ can be arbitrarily large. Therefore, we consider the subclass \(P_5^\ast\) of 3-polytopes in $P_5$ that avoid (5, 5, 6, 6, ∞)-vertices. For each $P^\ast$ in $P_5^\ast$ without vertices of degree from 7 to 9, it follows from Lebesgue’s Theorem that $h_5(P^\ast) ≤ 17$. Recently, this bound was lowered by Borodin, Ivanova, and Kazak to the sharp bound $h_5(P^\ast) ≤ 15$ assuming the absence of vertices of degree from 7 to 11 in $P^\ast$. In this note, we extend the bound $h_5(P^\ast) ≤ 15$ to all $P^\ast$s without vertices of degree from 7 to 9.
Źródło:
Discussiones Mathematicae Graph Theory; 2020, 40, 4; 1025-1033
2083-5892
Pojawia się w:
Discussiones Mathematicae Graph Theory
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-4 z 4

    Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies