## The Shubnikov - de Haas and the de Haas - van Alphen effects in bulk crystals and low-dimension structures

Published in category «Condensed matter physics»

The Shubnikov and de Haas (SdH) as well as de Haas and van Alphen (dHvA) effects that allow the identification of quantum-dimensional processes of the energy and magnetic moment in solids are analyzed within frameworks of the classical Landau level formation under the conditions of the prolonged movement of carriers in three- and two-dimensional systems. The methods that are based on the SdH and dHvA effects are possible to be used as the powerful instrument to study quantum interference processes for the studies of the semiconductor nanostructures, with the dimensions close to the Fermi wavelength.

## The formation of physical-chemical properties of zeolite-nanoparticles system by mechanical activation

Published in category «Condensed matter physics»

Pore structure of zeolites modificated with nanoparticles of iron and iron oxides by mechanical mixing are investigated. The modification causes an increase in the specific surface and specific pore volume of zeolites at the cost of a microporosity increase.

## Nanoscale heterophasity and synchrotron radiation diffuse scattering in lead zirconate titanate single crystals near the morphotropic phase boundary

Published in category «Condensed matter physics»

The paper presents the results of quasielastic diffuse scattering of synchrotron radiation in lead zirconate titanate (PZT)single crystals. The experimental confirmation of the hypothesis of two-phase PZT near the morphotropic phase boundary in the investigated temperature range is achieved.

## Electronic properties of the Kronig - Penney model with semi-infinite lattice of random potential barriers

Published in category «Condensed matter physics»

By using the transfer matrices technique a problem on incidence of the Bloch wave on a semi-infinite one-dimensionallattice of δ-function potential barriers of random strength (the modified Kronig-Penney model) is solved. It is shown that anarbitrarily small uncorrelated perturbation of the periodic potential makes the propagation of undamped Bloch waves characteristic for the classical Kronig-Penney model into the lattice impossible. The extinction length of the Bloch wave is calculated.

## Determinations of electrokinetic properties of semiconducting materials for making nanocathods

Published in category «Condensed matter physics»

The interaction of the pulse laser radiation with the solid state samples were studied using the method of the femtosecond laser reflection spectroscopy. The time dependences of the induced reflection coefficient were analyzed. This analysis allowed to measure the relaxation time of free carriers and to formulate the basic technique of development of nanocomposite cathodes based on rare-earth metals with semiconductor impurities.

## The light induced thermal lens dynamics in a binary fluid medium

Published in category «Simulation of physical processes»

The thermal-mass transport processes in a binary fluid medium which is under the influence of the radiation taking into account thermal diffusion flows are analysed. The expression for a focal distance of the thermoinduced lens resulting self-action of a light field is found.

## Geometrically nonlinear thermoelasticity mathematic models of shells with the variable thickness

Published in category «Simulation of physical processes»

The mathematical deformation models of variable thickness shells (smoothly-variable and ribbed shells), experiencing either mechanical load or permanent temperature field and taking into account the geometrical nonlinearity and transverse shear, have been developed. There are given refined geometrical proportions for geometrically nonlinear and steadiness problems.

## The simulation of nonlinear behavior for ferroelectric ceramics with tetragonal structure by finite-element homogenizing

Published in category «Simulation of physical processes»

The application possibility for the model of ferroelectroelastic material based on the testing of effective properties of polycrystal using the methods of finite element homogenization to describe the cyclic loading of polycrystalline piezoceramics has been investigated. The results of finite element solution for nonlinear coupled electro-mechanical problems for a representative volume element of the polycrystal were presented. They were compared with experimental results under various loading conditions.

## Taking account the lamination factor in electromagnetic processes simulation

Published in category «Simulation of physical processes»

The article describes the numerical simulation of technology based on vector and scalar potentials and taking into account anisotropic properties of the medium in the form of magnetic permeability and electrical conductivity tensors. The possibilities of using this technology for taking into account laminated materials influence are discussed. The results of numerical experiments demonstrating the possibilities of the proposed method are presented.

## The computational approach to the problem of quantitative XRF analysis for complex geometry samples

Published in category «Simulation of physical processes»

The paper considers the inhomogeneous sample analysis by XRF method. The method of XRF-tomography and imitation program are described.

## The spatial distribution features of Сherenkov photon flux in the core of an electron-photon extensive atmospheric shower induced by a 5 GeV primary gamma-quantum

Published in category «Simulation of physical processes»

Modeling of the electromagnetic component of an extensive atmospheric shower induced by a 5 GeV primary gamma-quantum is performed. It is shown that at 5 km a.s.l. the mean value of Cherenkov photon flux is 0.2 - 0.5 photon/m2 depending on the distance from the axis of shower (within the distance of 200 m).

## Electrical impedance of flat piezotransducer loaded on environment through the contact layer fluid

Published in category «Mathematical physics»

On the basis of the piezoeffect equations an expression for an electrical impedance of the flat piezotransducer loaded on the environment through a contact layer of a liquid has been received. It is shown that presence of a thin strongly reflecting contact layer leads to that the spectrum of natural frequencies becomes not the equidistant, and good quality of oscillations10 times more, than in a case flat piezotransducer loaded immediately on the environment.

## New key dual series equations connected with axisymmetric torsioin problem for an elastic space containing spherical crack

Published in category «Mathematical physics»

With the help of dual equations method exact solutions are obtained for a class of series relations in associated Legendre functions. Those dual series relations arise in axisymmetric torsion problem for an elastic space containing spherical crack.

## Testing procedure development for multileaf collimator in remote radiation therapy

Published in category «Experimental technique and devices»

The testing results for the work of 48-leaf collimator set up on the Mevatron Primus Siemens linear medical electron accelerator have been considered on evidence obtained by film dosimetry. On testing there were estimated such parameters as the gentry and the collimator attitudes relative to the zero-level, the collimator leafs positions while the gentry and the collimator were rotating, interleaf and interblock radiation leakages, wedge factors for physical and virtual wedges, radiation field dimensions. Practical recommendations on specification and periodicity of calibration procedures for clinical conditions are given.

## Glucose concentration testing in the biological tissue by coherent optical polarimetry

Published in category «Experimental technique and devices»

The testing results for the work of 48-leaf collimator set up on the Mevatron Primus Siemens linear medical electron accelerator have been considered on evidence obtained by film dosimetry. On testing there were estimated such parameters as the gentry and the collimator attitudes relative to the zero-level, the collimator leafs positions while the gentry and the collimator were rotating, interleaf and interblock radiation leakages, wedge factors for physical and virtual wedges, radiation field dimensions. Practical recommendations on specification and periodicity of calibration procedures for clinical conditions are given.

## A principle of the conformal transformation of elecrostatic fields

Published in category «Physical electronics»

Two-dimensional electric fields with ideal focusing are considered. The procedure for a potential and charged particles trajectories transformation into the conformal coordinates by means of methods of the theory of functions of a complex variable is outlined. Various transformations of the Korsunsky field are shown. Energy dispersion is calculated for one of the transformed field.

## The nonlinearity influence of acousto-optic interaction in the paratellurite modulator on the formation of harmonious signals imaging

Published in category «Physical optics»

The influence of acousto-optical nonlinearity on diffraction efficiency at the high amplitude ultrasonic signals is investigated theoretically. Waveform distortion in the light image formed by paratellurite acousto-optical modulator is considered.

## Modelling of a creep and a damage processes for high-temperature chromium P-91 steel

Published in category «Physical materials technology»

The simulation of a creep and a damage processes for P91 type heat-resistant steel on the ground of constitutive equation with internal state damage variable in a wide stress range is proposed. The damage-creep strain relation is defined from standard creep test data in two forms: power law and exponential. The proposed model allows to obtain constant stress creepcurves for 10XCrMoVNb-9-1 (P91) steel under Т = 625°С in consideration of the primary and tertiary creep stages and creep strength in a wide stress range.

## The effect of the ion-exchange treatment and gamma-irradiation on the spectra of phosphate glasses doped with europium

Published in category «Physical materials technology»

Spectroscopic investigation of boron-phosphate glasses of variable alkali compositions, doped with europium, revealed growth of Eu{3}+ concentration and reducement of Eu{2}+ concentration in case of replacement of Li by Na. Glasses of variable compositions were treated in molten salt, as a result one could see growth of Eu{2}+ concentration and reducement of Eu{3}+concentration. It has been shown that ion-exchange treatment increases the amount of hole PO[4]{2-} defects caused by gamma-radiation.

## Durability of polymer light emitting diodes

Published in category «Physical materials technology»

The paper discusses the physical reasons for the limited efficiency of organic light-emitting diodes. The evaluation of lifetime of organic materials in strong electric fields is made.

## An analysis of molecular mechanisms of stretching of short fragments of DNA double stranded

Published in category «Biophysics and medical physics»

In this work we have developed algorithms and computer programs for stretching of dsDNA with arbitrary nucleotide sequence and structure with ICM-Pro - software package for molecular modeling of biomacromolecules.The differences in structure transitions in dsDNA under stretching from 3' and 5' DNA ends investigated.

## Viscous-elastic biopolymers: physical-mechanical properties and application in ophthalmology

Published in category «Biophysics and medical physics»

The investigation problems of viscous-elastic biopolymers physical-mechanical properties are considered in the paper.The technologies of surgery in the eye cataract treatment are described.

## The effect of the external constant electric field on dipole moment of LC main-chain polymer

Published in category «Physics of molecules»

The comparison study of dipole moments of LC main-chain polymer (I) and its low-molecular analog (II) under applied external electric field of 10 kV/cm was carried out. It was found temperature dependences of dipole moment of (I) and (II) at the absence of external electric field were similar. Under external electric field the dipole moment of (II) doesn’t change but the dipole moment of (I) dramatically reduced with temperature revealing intramacromolecular transition at 50 °C. The Kirkwood factor varies from 0,94 at 20 °C to 0,35 at 70 °C.

## Optimization of discrimination effect of the dual-energy method in radioscopy

Published in category «Nuclear physics»

In this work we consider the possibility of material discrimination improvement for groups of effective atomic number values in radioscopy of large-sized objects at the expense of the bremsstrahlung preliminary filter installation. Optimum values of filter parameters and dual energy of the accelerator for the best material discrimination are evaluated.

## The behavior of invariant amplitudes of nucleon-nucleon scattering

Published in category «Nuclear physics»

Two-dimensional electric fields with ideal focusing are considered. The procedure for a potential and charged particles trajectories transformation into the conformal coordinates by means of methods of the theory of functions of a complex variable is outlined. Various transformations of the Korsunsky field are shown. Energy dispersion is calculated for one of the transformed field.

## Hadron production in lepton-nucleus interactions at high energies

Published in category «Nuclear physics»

Hadron production in lepton-nucleus interactions at high-energies is considered in framework of developing Monte Carlo(MC) generator HARDPING (Hard Probe Interaction Generator). Such effects as formation length, energy loss and multiple rescattering for produced hadrons are implemented into the HARDPING. Available data from HERMES on hadron production in lepton-nucleus collisions are described by the current version of the HARDPING generator in a reasonable agreement.

## Solution examples of the Cauchy problem for some variants of the Frankl system of elliptic type

Published in category «Mathematics»

The work contains examples of faithful analytic solutions of the Cauchy problem for some elliptic systems of the first order quasilinear partial differential equations. The solutions are presented in explicit forms and in initial variables.The method of an additional argument as basical one has allowed to establish the qualitative causes of an incorrectness of solutions and to define conditions of the classical solutions existing.

## An experimental investigation of the pulsing gas efflux from the receiver

Published in category «Mechanics»

Two alternative schemes of a pulsing subsonic air efflux from the receiver with an elevated pressure to the atmosphere have been investigated. The 1st efflux takes place only through the closing unit, the 2nd one - through the closing unit which has the attached cylindrical pipe of the long extending. The frequency dependences of flow rate were obtained. It was established that the pipe presence (the 2nd scheme) can cause a change up to 20 per cent in the flow rate at resonance frequencies and the flow rate increase over a range of moderate frequencies (10 - 80 Hz) when compared two schemes at the same action frequencies of the closing unit operating in the pulse mode of gas efflux.

## Nikolay Nicolaevich Lebedev (on occasion of his 100th birthday)

Published in category «Chronicle»