Главная
Авторизация
Фамилия
Пароль
 

Базы данных


Труды сотрудников ИФ СО РАН - результаты поиска

Вид поиска

Область поиска
в найденном
 Найдено в других БД:Каталог книг и брошюр библиотеки ИФ СО РАН (2)
Формат представления найденных документов:
полный информационныйкраткий
Отсортировать найденные документы по:
авторузаглавиюгоду изданиятипу документа
Поисковый запрос: (<.>S=MOLECULES<.>)
Общее количество найденных документов : 9
Показаны документы с 1 по 9
1.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Averyanov E. M.
Заглавие : Orientational order and critical-behavior of a discoid nematic liquid-crystal
Место публикации : JETP Letters. - 1995. - Vol. 61, Is. 10. - P.815-820. - ISSN 0021-3640
Примечания : Cited References: 14
Предметные рубрики: MOLECULES
Аннотация: First experimental data on the orientational order of the molecules in a discoid nematic liquid crystal are reported. These results are dramatically at odds with the results of a numerical simulation for rigid disk-shaped molecules. The N-D-I phase transition is simultaneously close to an isolated Landau critical point and to the tricritical point, as in ordinary calamite nematic liquid crystals with Planckian molecules. This result indicates that conformational degrees of freedom of the molecule play an important role in the features of the N-D-I transition. (C) 1995 American Institute of Physics.
WOS
Найти похожие
2.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Averyanov E. M.
Заглавие : Character of the N-D-D-h(0,d) phase transition in diskotic liquid crystals
Место публикации : JETP Letters. - 1996. - Vol. 63, Is. 1. - P.33-37. - ISSN 0021-3640, DOI 10.1134/1.566959
Примечания : Cited References: 20
Предметные рубрики: MOLECULES
CONSTANTS
SPLAY
BEND
Аннотация: The first experimental data on the orientational ordering of a diskotic reentrant nematic N-D are presented. The data show that the phase transition N-D-D-h(0,D-d) is a strong first-order transition with a large jump Delta S similar or equal to 0.2 in the orientational order parameter S of the molecules. This indicates an anomalously strong coupling between the columnar and orientational ordering of the molecules and explains the absence of fluctuational divergence of the elastic moduli K-11 and K-22 in the nematic phase near this transition. (C) 1996 American Institute of Physics.
WOS
Найти похожие
3.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Averyanov E. M.
Заглавие : Orientation ordering and critical behavior of discoid nematics
Место публикации : Zhurnal Eksperimentalnoi Teor. Fiz.: MEZHDUNARODNAYA KNIGA, 1996. - Vol. 110, Is. 5. - P1820-1840. - ISSN 0044-4510
Примечания : Cited References: 55
Предметные рубрики: LIQUID-CRYSTALS
PHASE-TRANSITION
ISOTROPIC-PHASE
LOCAL FIELD
SMECTIC-A
MOLECULES
SUSCEPTIBILITY
CONFORMATION
PARAMETER
DYNAMICS
WOS
Найти похожие
4.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Di Valentin C., Neyman K. M., Risse T., Sterrer M., Fischbach E., Freund H. J., Nasluzov V. A., Pacchioni G., Rosch N.
Заглавие : Density-functional model cluster studies of EPR g tensors of F-s(+) centers on the surface of MgO
Разночтения заглавия :авие SCOPUS: Density-functional model cluster studies of EPR g tensors of F s + centers on the surface of MgO
Место публикации : J. Chem. Phys.: AMER INST PHYSICS, 2006. - Vol. 124, Is. 4. - Ст.44708. - ISSN 0021-9606, DOI 10.1063/1.2161190
Примечания : Cited References: 37
Предметные рубрики: ELECTRONIC G-TENSORS
CORRELATION-ENERGY
MGO(001) SURFACE
OXYGEN VACANCIES
SPIN-ORBIT
G-VALUES
ATOMS
APPROXIMATION
COMPLEXES
MOLECULES
Ключевые слова (''Своб.индексиров.''): density-functional model cluster--single-crystalline thin films--spin-orbit interaction--anisotropy--paramagnetic resonance--single crystals--tensors--thin films--magnesium compounds
Аннотация: We report g tensors of surface color centers, so-called F-s(+) centers, of MgO calculated with two density-functional approaches using accurately embedded cluster models. In line with recent UHV measurements on single-crystalline MgO film, we determined only small g-tensor anisotropies and negative shifts Delta g equivalent to g-g(e) for all F-s(+) sites considered, namely, (001)-terrace, step, edge, and corner sites. The g values are very sensitive to the local structure of the defect: relaxation reverses the sign of Delta g. However, accounting for the spin-orbit interaction either self-consistently or perturbatively yields very similar results. In addition to the values of the tensor components, their direction with respect to the surface was determined. In contrast to edges, significant deviations from ideal C-2v symmetry were found for F-s(+) centers at steps. Recent data on single-crystalline thin films are reevaluated in the light of these results. (c) 2006 American Institute of Physics.
WOS,
Scopus,
Читать в сети ИФ
Найти похожие
5.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Gerasimova J. V., Vtyurin A. N.
Заглавие : Evans hole in internal modes IR spectrum of WO3F33-ions in (NH4)(3)WO3F3 crystal
Место публикации : Chem. Phys. Lett.: ELSEVIER SCIENCE BV, 2012. - Vol. 523. - P.144-147. - ISSN 0009-2614, DOI 10.1016/j.cplett.2011.12.041
Примечания : Cited References: 11. - We would like to thank Prof. E. M. Aver'yanov for discussion, and V. A. Ouskin for the technical assistance. This work has been supported by the Russian Foundation for Basic Researches, Grant No. 11-02-98002-r_sibir_a.
Предметные рубрики: INFRARED-SPECTRA
PHASE-TRANSITIONS
OXYFLUORIDE
MOLECULES
Аннотация: Infrared absorption of (NH4)(3)WO3F3 compound has been studied. Profile of asymmetric band in 600-1000 cm (1) range associated with polar W-O vibrations of WO3F33- ions is explicable on the basis of multi-oscillatory dynamics with account of damping. Complex profile with Evans holes proves that internal modes of WO3F33- anions in the fluorine-oxygen octahedron interact due to the effects of the local field. (C) 2011 Elsevier B. V. All rights reserved.
Смотреть статью,
Scopus,
WoS,
Читать в сети ИФ
Найти похожие
6.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Aver'yanov E. M.
Заглавие : New features of a smectic-A-crystal-B phase transition in a homologous series of liquid crystals
Место публикации : JETP Letters. - 2014. - Vol. 99, Is. 3. - P.158-163. - ISSN 0021-3640, DOI 10.1134/S0021364014030047. - ISSN 1090-6487
Примечания : Cited References: 21
Предметные рубрики: POLARIZABILITY
POLYMORPHISM
ANISOTROPY
MOLECULES
BEHAVIOR
Аннотация: The components L j of the Lorentz tensor and the polarizability density of molecules G in the smectic-A and crystalline-B phases have been determined for homologues of the series of alkyl-p-(4-alkoxybenzylideneamino-)cinnamates. The quantity L j (G) in both phases is a linear (quadratic) function of the orientational order parameter of molecules S, which is invariant (noninvariant) with respect to the A-B transition, which is manifested in the form of jumps δL j and δG and enhancement of the G(S) dependence. An increase in the length of terminal molecular chains and weakening of interlayer correlation of molecules are accompanied by strengthening of the A-B transition of the first order and G(S) dependences in both phases together with an increase in δL j and δG. Change δG and dependence G(S) in the B phase are related to change in the conformation (flattening) of aromatic molecular cores.
Смотреть статью,
Scopus,
WoS,
Читать в сети ИФ
Найти похожие
7.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Aver'yanov E. M.
Заглавие : Structural and thermodynamic consequencies of the interaction of conformational degrees of freedom of azomethines in the nematic phase
Место публикации : J. Struct. Chem.: Springer, 2014. - Vol. 55, Is. 4. - P.605-611. - ISSN 0022-4766, DOI 10.1134/S0022476614040039. - ISSN 1573-8779
Примечания : Cited References: 21
Предметные рубрики: CONJUGATED POLY(AZOMETHINE)S
TERMINAL SUBSTITUENTS
ELECTRONIC-STRUCTURES
FLUORINATED ANALOGS
INTERNAL-ROTATION
MOLECULES
COMPOUND
ANGLES
STATE
NMR
Ключевые слова (''Своб.индексиров.''): azomethines--benzylideneaniline--conformation--steric effects of substituents--nematic-isotropic liquid transition--conformational polymorphism
Аннотация: The interaction of the conformational degrees of freedom of azomethines in the nematic phase, which is induced by electronic donor-acceptor properties of the terminal substituents of the benzylideneaniline core is studied. These degrees of freedom related to the rotation angles phi (k) around the bonds between the substituent and the aniline ring (phi(1)) and also between the CH=N bridge and the aniline ring (omega(2)) are characterized by the parameters Q (k) = aOE (c) cos(2)phi (k) . It is found that the interaction of these degrees of freedom is manifested in the linear dependence Q (2)(Q (1)). Within the phenomenological theory the effect of this interaction on changes delta (k) in the Q (k) values during the nematic liquid crystal-isotropic liquid phase transition is revealed along with the temperature T (NI) and character of this transition. The derivation of previously established empirical dependences T (NI)(Q (k) ) is presented in the presence of direct and indirect steric effects of side substituents affecting the Q (k) values. A diverse combination of delta (k) signs in the nematic phase, which is a prerequisite for the conformational polymorphism of the nematic phases of azomethines, is shown.
Смотреть статью,
Scopus,
WOS,
Читать в сети ИФ
Найти похожие
8.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Аверьянов, Евгений Михайлович
Заглавие : Температурные зависимости показателей преломления одноосных каламитных жидких кристаллов с высоким двупреломлением
Место публикации : Жидк. кристаллы и их практич. использ. - 2018. - Т. 18, № 2. - С. 53-63. - ISSN 1991-3966, DOI 10.18083/LCAppl.2018.2.53; Liq. Cryst. Appl.
Примечания : Библиогр.: 29
Предметные рубрики: PHASE-TRANSITION
ORIENTATIONAL ORDER
ISOTROPIC LIQUID
MOLECULES
Ключевые слова (''Своб.индексиров.''): жидкие кристаллы--температурные зависимости показателей преломления--liquid crystals--temperature dependences of the refractive indices
Аннотация: Температурные зависимости показателей преломления nj(t) и величин n(t) = (n|| + 2n⊥)/3, n(t) =ε-1/2, ε= (ε|| + 2ε⊥)/3, εj = nj2 для световых волн с поляризацией вдоль (j = ||) и нормально директору (j = ⊥) в одноосных каламитных жидких кристаллах (ЖК) исследованы в рамках микроскопического подхода с учетом анизотропии тензора локального поля fj(t) =1 + Lj(t)[εj(t)–1] и тензора Лорентца Lj(t). Показано, что известные отрицательные производные n(t)' = dn(t)/dt, n' и точка to минимума на зависимости n⊥(t) в каламитных ЖК отвечают малым и средним значениям двупреломления Δn = n|| – n⊥. Для ЖК с высокими величинами Δn и компонентами L⊥, превышающими пороговое значение L⊥e(nj), предсказаны два новых эффекта: положительные значения n', и наличие точки te максимума на зависимости n||(t). Для ряда нематиков с высокими значениями Δn определены компоненты Lj(t), подтверждено наличие предсказанных эффектов и условий их проявления, получены значения te и прослежена их связь с величиной Δn. Выяснены особенности перехода от ЖК с точкой to к ЖК с точкой te по мере роста Δn.The temperature dependences of the refractive indices nj(t) and the values n(t) = (n|| + 2n⊥)/3, n(t) =ε-1/2, ε= (ε|| + 2ε⊥)/3, εj = nj2 for the light waves polarized along (j = ||) and across (j = ⊥) the director in uniaxial calamitic liquid crystals (LCs) were studied within the microscopic approach with taking into account the anisotropy of the local-field tensor fj(t) =1 + Lj(t)[εj(t)–1] and the Lorentz tensor Lj(t). The known negative derivatives n(t)' = dn(t)/dt, n' and the point to of minimum at the dependence n⊥(t) for calamite LCs were shown to correspond to small and medium values of the birefringence Δn = n|| – n⊥. For LCs with high values of δn and components L⊥ exceeding the threshold value L⊥e two new effects were predicted: positive derivatives n', and the presence of the point te of maximum at the dependence n||(t). For a number of nematics with high values of Δn the components Lj(t) were determined, the presence of the predicted effects and the conditions for their manifestation were confirmed, the values te were obtained and their connection with the magnitude Δn were established. The features of the transition from LCs with point to to LCs with point c under gradual increase in Δn were cleared up.
Смотреть статью,
РИНЦ,
Scopus,
WOS,
Читать в сети ИФ
Найти похожие
9.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Liu, Yan Rong, Wu, Yong, Wang, Jian Guo, Vendrell, Oriol, Kimberg V., Zhang, Song Bin
Заглавие : Electron-rotation coupling in diatomics under strong-field excitation
Место публикации : Phys. Rev. A. - 2020. - Vol. 102, Is. 3. - Ст.033114. - ISSN 2469-9926, DOI 10.1103/PhysRevA.102.033114. - ISSN 2469-9934(eISSN)
Примечания : Cited References: 78. - S.B.Z. thanks H. D. Meyer for his helpful instructions of Wigner-DVR in MCTDH. Grants from the National Basic Research Program of China (2017YFA0403200), NSFC (No. 11604197, No. 11974230, and No. 11934004), the Science Challenge Program of China (TZ2018005 and TZ2016005) are acknowledged. V.K. acknowledges financial support from Swedish Research Council (VR) and the Ministry of Science and High Education of Russian Federation, Project No. FSRZ2020-0008.
Предметные рубрики: REAL-TIME OBSERVATION
DYNAMICS
LASER
ULTRAFAST
MOLECULES
Аннотация: he photoexcitation and photodissociation of diatomic molecules by intense pulse lasers has been the subject of extensive investigations over the past decades. However, the usually employed theoretical framework neglects the coupling between the molecular rotational angular momentum (R) and the angular momentum of the electrons projected onto the molecular axis Ω=Λ+Σ, which results in the known Λ-doubling phenomenon in high-resolution electronic spectra of diatomic molecules. While neglecting this coupling is an excellent approximation in the weak-field or perturbative regime owing to the large mass difference between the rotating atoms and the electrons, the approximation breaks down for intense laser pulses because of the repeated Rabi cycling of the electronic transitions, which can have a significant effect on the rotational degrees of freedom of the molecule. By correcting the transition dipole matrix elements and introducing angular basis sets based on Wigner D functions, the conventional theoretical treatment is generalized to a universal description valid for both the weak- and strong-field regimes. The theoretical treatment developed here is applied to the ∣1Σ› to ∣1Π› transitions in diatomic systems. Our results reveal that, for field intensities resulting in about one Rabi cycling for extreme ultraviolet or x-ray transitions, the theoretical predictions by the conventional theoretical frame need to be corrected when considering observables such as the molecular alignment and the angular distribution of the photofragments.
Смотреть статью,
Scopus,
WOS,
Читать в сети ИФ
Найти похожие
 

Другие библиотеки

© Международная Ассоциация пользователей и разработчиков электронных библиотек и новых информационных технологий
(Ассоциация ЭБНИТ)