Shock-free ferroelectric liquid crystal displays with high optical contrast

Shock-free ferroelectric liquid crystal displays with high optical contrast and low operating voltage are the concern of this contribution. Ferroelectric liquid crystal compositions with a wide temperature range of the chiral smectic C phase are designed. The influence of the chiral fragments of the molecules, especially their length, on the mechanical stability of the SmC phase has been investigated. The relation between the surface anchoring energy of the aligning polymer and the viscoelastic properties of the SmC phase has been described. Our qualitative model reflects the resistance of the SmC layer structure against mechanical and thermal action

Синтез 3,6-дизамещенных циклогексенонов и мезоморфные свойства их ароматических производных

The synthesis of 3,6-disubstituted cyclohex-2-еnones, their aromatization by phosphorous pentachloride and preparation of liquid crystalline compounds with high birefringence have been described. The mesomorphic properties of substituted terphenyls and quaterphenyls and their practical application in displays are discussed.Осуществлены синтез и ароматизация 3,6-дизамещенных циклогекс-2-енонов под действием пятихлористого фосфора. Рассмотрены жидкокристаллические свойства продуктов ароматизации, других мезоморфных производных 3,6-дизамещенных циклогекс-2-енонов, перспективы их практического использования в электрооптических устройствах отображения информации

Эффективный метод синтеза замещенных 2-метилбензофуранов

The efficient method for synthesis of substituted 2-methylbenzofurans based on aromatization of 3-substituted-6-allylcyclohex-2-еnones in the presence of iodine with subsequent potassium hydroxide treatment of 2-iodomethyl-2,3-dihydro-benzofuran intermediates, has been described.Предложен эффективный метод синтеза замещенных 2-метилбензофуранов, основанный на ароматиза-ции 3-замещенных-6-аллилциклогекс-2-енонов в присутствии иода, последующей обработке промежуточных 2-иодметил-2,3-дигидробензофуранов гидроокисью калия

Liquid crystal displays and anisotropic materials development in Belarus: present and future

Research, development and production of liquid crystal displays and materials in Belarus are presented. The original methodology of the creation of advanced devices and anisotropic materials is considered. The proposed approach of design of new devices, anisotropic materials and ordered nanostructured surfaces and layers is based on numerous data obtained in the last decades in the study of liquid crystals and ordered fluids; on the regularities of the evolutionary development of natural organic compounds; on the use of the anisotropy of the molecules of polyfunctional compounds for the design of new molecular structures (molecular engineering), films, liquid crystals, micelles, membranes, etc. and for the creation of anisotropic ensembles of molecules and biological systems

Extinction threshold in the spatial stochastic logistic model: space homogeneous case

We consider the extinction regime in the spatial stochastic logistic model in R^d (a.k.a. Bolker–Pacala–Dieckmann–Law model of spatial populations) using the first-order perturbation beyond the mean-field equation. In space homogeneous case (i.e. when the density is non-spatial and the covariance is translation invariant), we show that the perturbation converges as time tends to infinity; that yields the first-order approximation for the stationary density. Next, we study the critical mortality – the smallest constant death rate which ensures the extinction of the population – as a function of the mean-field scaling parameter ε>0. We find the leading term of the asymptotic expansion (as ε→0) of the critical mortality which is apparently different for the cases d≥3, d = 2, and d = 1

Shock-free ferroelectric liquid crystal displays with high optical contrast

Shock-free ferroelectric liquid crystal displays with high optical contrast and low operating voltage are the concern of this contribution. Ferroelectric liquid crystal compositions with a wide temperature range of the chiral smectic C phase are designed. The influence of the chiral fragments of the molecules, especially their length, on the mechanical stability of the SmC phase has been investigated. The relation between the surface anchoring energy of the aligning polymer and the viscoelastic properties of the SmC phase has been described. Our qualitative model reflects the resistance of the SmC layer structure against mechanical and thermal action