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91.
The director structures, meniscus profile, and defects in free-standing films of the twist grain boundary TGBA and UTGBC* liquid crystals were studied. The films were characterized by a combination of polarizing microscopy and fluorescence confocal polarizing microscopy. Five principal regions of meniscus were distinguished. When film thickness in the meniscus is much smaller then the TGB pitch, there is no difference between the free-standing films of TGB and ordinary smectic A liquid crystals. When the film thickness is larger than the TGB pitch, filamentary texture is observed. The 3D director pattern of the filaments are similar to the ground state director fields of TGBA and UTGBC* liquid crystals. In the intermediate thickness region of the meniscus, when the film thickness and TGB pitch are commensurate, a unique radial pattern is observed. Based on the fluorescence confocal polarizing microscopy studies of the director field, we propose a model for the 3D director structure in this part of the meniscus. 相似文献
92.
A nearlattice S is a meet semilattice together with the property that any two elements possessing a common upper bound have a supremum. Here the authors have introduced the notion of sectionally semicomplemented distributive nearlattices and given several characterizations of them. The skeleton SCon(S) of Con(S), the congruence lattice, consists of all those nearlattice congruences which are the pseudocomplements of members of Con(S). The relationship between skeletal congruences and kernel of skeletal congruences leads to numerous characterizations of sectionally semicomplemented distributive nearlattices and semiboolean algebras. For example we prove, for a distributive nearlattice S with 0, the following conditions are equivalent:
AMS Subject Classifications (1991): 06A12, 06A99, 06B10. 相似文献
(i) | S is sectionally semicomplemented |
(ii) | The map Θ Θ ̸ker Θ of SCon(S) onto KSCon(S) is one-to-one. |
(iii) | The map Θ Θ ̸ker Θ of SCon(S) onto KSCon(S) preserves finite joins. |
(iv) | The map Θ Θ ker ̸Θ is a lattice isomorphism of SCon(S) onto KSCon(S), whose inverse is the map J ̸ Θ(J)**. |
93.
Summary The existence of the parity-breaking phase transition between untwisted and twisted bipolar structures of the tangentially
anchored spherical nematic drops has been shown experimentally. Twisted structures behave like the optically active objects
in spite of the nonactivity of nematic and isotropic matrix themselves. Temperature dependences of the order parameter (twist
angle) have been determined for the drops of 8 CB and 8 OCB. It has been shown that these dependences are very similar to
that observed in usual second-order phase transition.
Work presented at the second USSR-Italy Bilateral Meeting on Liquid Crystals held in Moscow, September 15–21, 1988. 相似文献
94.
A magnetized Iron CALorimeter (ICAL) detector at the India-based neutrino observatory (INO) is used to study neutrino oscillation sensitivity using atmospheric muon neutrino source. The ICAL detector will be able to detect muon tracks and hadron showers produced by neutrino interactions with the iron target. We have performed precision measurement analysis for the atmospheric neutrino oscillation parameters with the muon neutrino events, generated by Monte Carlo NUANCE event generator. A marginalized χ2 analysis based on reconstructed neutrino energy and muon zenith angle binning scheme has been performed to determine the sensitivity for the atmospheric neutrino mixing parameters, \(\sin ^{2}\theta _{23}\) and \(| {\Delta } m^{2}_{23}|\). 相似文献
95.
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99.
We report on a thermodielectric bistability in dual frequency nematic liquid crystals (LCs) caused by the anisotropic nature of dielectric heating and director reorientation in an electric field. The bistability is a result of the positive feedback loop: director reorientation --> anisotropic dielectric heating --> dielectric anisotrophy --> director reorientation. We demonstrate both experimentally and theoretically that two states with different temperature and director orientation, namely, a cold planar state and a hot homeotropic state coexist in a LC cell for a certain frequency and amplitude range of the applied voltage. 相似文献
100.
For ?1≤B<A≤1, let \(\mathcal {S}^{*}(A,B)\) denote the class of normalized analytic functions \(f(z)= z+{\sum }_{n=2}^{\infty }a_{n} z^{n}\) in |z|<1 which satisfy the subordination relation z f ′(z)/f(z)?(1 + A z)/(1 + B z) and Σ?(A,B) be the corresponding class of meromorphic functions in |z|>1. For \(f\in \mathcal {S}^{*}(A,B)\) and λ>0, we shall estimate the absolute value of the Taylor coefficients a n (?λ,f) of the analytic function (f(z)/z)?λ . Using this we shall determine the coefficient estimate for inverses of functions in the classes \(\mathcal {S}^{*}(A,B)\) and Σ?(A,B). 相似文献