The Kinetics of Nematic Phase Separation on Cooling the Isotropic Phase of Mesogenic Siloxane-Azomethine Polyether

The kinetics of nematic phase droplet growth as an isotropic melt of mesogenic siloxane-azomethine polyether was cooled was studied by polarizing microscopy. The results were processed statistically and described using the thermodynamics of irreversible processes. An analysis of the time dependences of statistical distribution parameters revealed the occurrence of two regimes of phase separation, (1) the formation of droplets and their growth and (2) coalescence of droplets. Both regimes were quantitatively described by the universal law of the growth of clusters.     

Computational methods and software in computer-aided combinatorial library design

Recent trends in the computer-aided design of diverse and focussed combinatorial libraries are surveyed. First, chemical data input, storage and retrieval including chemical database management and virtual chemical structure enumeration are outlined as background. Then, the optimization of ADMET parameters, diversity maximization, molecular similarity search, QSAR-based virtual screening, pharmacophore search and molecular docking are discussed.     

Spectral structure of polarization radiation from relativistic electrons in aluminum

Collective effects in polarization bremsstrahlung generated by relativistic electrons in a polycrystalline aluminum foil are studied experimentally on the basis of the 2.4-MeV electron accelerator installed at the Institute of Nuclear Physics (Moscow State University, Moscow). A peak structure found in this polarization bremsstrahlung for the first time is in agreement with theoretical predictions. __________ Translated from Yadernaya Fizika, Vol. 63, No. 11, 2000, pp. 2097–2100. __________ Translated from Yadernaya Fizika, Vol. 63, No. 11, 2000, pp. 2097–2100.     

Studying the interaction of 10-keV electrons with a dielectric surface

The grazing incidence interaction of a 10-keV electron beam with a planar surface of plexiglass is studied experimentally. Moreover, the electron passage through flat channels formed by such surfaces is investigated. The experiments reveal the presence of a guiding effect of the electron passage as in the case of a glass surface. However, there are some features, such as the existence of an initial elevation angle for the case of negative inclination angles of the plate. The formation of self-consistent charge on the surface of the plexiglass and its drain when the current is turned off occur more slowly than on the glass surface. This fact points to the difference in the surface conductivity of insulators.     

Diagnostics of nanodisperse polycrystals based on the polarization bremsstrahlung of relativistic electrons

The spectra of polarization bremsstrahlung are measured in the backscattering geometry during the interaction of 7-MeV electrons with a polycrystalline Ni foil. Measurement is conducted under conditions such that the size of the region of coherent X-ray radiation scattering in a target is on the order of 10 nm. The obtained results make it possible to suggest that using polarization bremsstrahlung as a new method for the diagnostics of the atomic structures of nanodisperse polycrystals is effective.     

Selection of Simulating Signal-Like Interference in Radar Systems with Internal Coherence

Radiophysics and Quantum Electronics - We propose and study a method of defense against intelligent simulating signal-like active interference on the basis of an assessment of the coherent...     

On relativistic electron bremsstrahlung in thin targets

The simple model of relativistic electron bremsstrahlung in a thin target is presented for conditions when its thickness less then a photon formation length. Results of our calculations obtained with account of an influence of target dielectric properties are in agreement with data at 25 GeV electron bremsstrahlung in thin layers of different media.     

X-ray diagnostics of grain shapes in nanomaterials

It is demonstrated that an efficient method can be created and used to determine the shape of grains in nanomaterials. This method relies on the discovered correlations between the amplitudes of different Bragg peaks for wideband X rays scattered in the sample on the grain shape.