In the present work the possibility of CPT invariance examination of the bound states in quantum electrodynamics (QED) is considered. For this purpose, we calculated the cross section for the processes (μ^-+Z→Z+M⁰+e^-, μ⁺+Z→Z+M⁰+e⁺, μ⁺+M⁰+e^- and μ^-+μ⁺→μ^-+M⁰+e⁺. The differential cross section via the invariant mass of (M⁰,e⁺)- or (M⁰,e^-)-system and the total cross section of the above processes in the framework of QED are obtained. The total cross-sections and number of events for muon-nucleus scattering are larger (about 300 times) than ones for electron-nucleus scattering.

Cross sections for the reactions of muonium (anti-muonium) production in high energy electron(positron) scattering by nuclei e^-(e⁺) + Z Z +M⁰(M⁰) + μ^-(μ⁺) are calculated in dependence on an energy and polarization of an initial electron(positron) and a final μ^-(μ⁺)--meson polarization. Due to coherent phenomenon the cross sections are proportional to Z². For Z~100 due to the factor Z² the cross sections are large enough to be measured at energies available at HERA Collider in DESY. The results are discussed in connection with a test of CPT invariance.

Integrated polarization and quantum yield spectra of the electrons, photoemitted from strained AlInGaAs layer, capped by heavily doped thin GaAs quantum well layer, as well as high resolution energy distriubtion curves and a polarization versus energy distribution curves are studied as a function fo light excitation energy and power. The polarization P of up to 83% in conjunction with quantum yield Y=0.5 at T=130K have been measured. At high excitation intensity decrease of Y and P is observed which is attributed to the surface photovoltage effects, i.e. decrease of the negative electron affinity, narrowing of the band-bending region and an increase of the hole concentration in the quatnum well layer. The narrow-band quantum well is shown to provide high effective negative electron afffinity values with no harm to electron polarization.

Spin-polarized electron kinetics is studied by time-resolved polarized photoemission with picosecond resolution. The response time of strained layer photocathodes is found to be in a range of a few picosecond offering an ultrafast response and high spin-polarization of emitted electrons. The studies of the sub-picosecond spin dynamics are facilitated in high-intensity excitation regime when the length of the emission pulse is enlarged due to the dispersion of acceleration time and Coulomb repulsion of the electrons in their flight in the vacuum.

A full-potential linearized augmented plane wave (FLAPW) method is used to investigate (MeAs)₁(GaAs)_n (001) multi-layer structures wiht Me=Al, In, Cs as well as GaAs (001) and (110) surfaces. The layer-resolved densities of states, electron energy spectrum and valence charge-densities are analyzed. The adsorption of cesium is studied on both GaAs surfaces. The coverage dependence of the work function is obtained and is found to be in satisfactory agreement with experiments.

New results of many electron calculations of 4p-subshell photoionization cross section for Kr, Rb⁺, Sr²⁺, and Y are presented. The resonance structure associated with excitation of autoionizing 4s4p⁶np states has been studied. The dynamic polarization and screening effects are taken into account for calculations of resonance parameters. Double-electron excitations is shown to play a crucial role in describing the resonance shapes and widths.

In this contribution we present the results of calculations on electron photodetachment from inner shell of Li^- negative ion. The main attention is paid to taking into account for 1s photodetachment with simultaneous excitation of outer 2s-shell electron. This process leads to formation of resonant structure in photoionization cross section.

Elastic scattering of electrons on negative Li^- ion is considered within the Hartree-Fock approximation and the Dyson Equation method. The scattering phases of partial elastic s-, p- and d-waves and the partial cross sections have been calculated as a function of electron energy. The significant role of polarization interaction between the incoming electron and negative ion is shown. The results of these calculations are compared with results obtained within model consideration.

Scintillation properties of cerium fluoride crystals doped with different di-, tri-, and four-valent cations have been studied. Luminescence spectra, light output and kinetics have been measured. The influence of the valence state of the impurity on the scintillation properties of cerium fluoride is discussed.

In the present work, Fe doped InP substrates were annealed at high temperatures and the effect of annealing on optical absorption spectra was systematically examined. The absorption experiments at low temperature show both a characteristic spectrum of four zero-phonon lines, which are attributed to transitions within the ⁵D ground state of Fe²⁺(3d⁶) ion on the indium site in a tetrahedral crystal field of phosphorus atoms and addition spectrum consisting of two peaks. The lines fall in the energy range close to that of optical transitions at Fe²⁺ ions in InP. The level scheme can be modeled by an Fe²⁺ ion that experiences a weak (111) distortion, and has a 1% lower crystal field splitting parameter Dq than exactly tetrahedral coordinated Fe²⁺. Zeeman measurements lead us to ascribe the new spectrum to (Fe²⁺_In-V_P) pairs.

No abstract available.

Molecular dynamics (MD) simulations were carried out for (i) hydrated bilayers of phosphatidylcholines (PCs): 1,2 stearoyl-sn-glycero-3-PC (18:0/18:0 PC), 1-stearoyl-2-oleoyl-sn-glycero-3-PC (18:0/18:1ω9cis PC), 1-stearoyl-2-linoleoyl-sn-glycero-3-PC (18:0/18:2ω6cis PC), 1-stearoyl-2-lineolenoyl-sn-glycero-3-PC (18:0/18:3ω3cis PC), 1-stearoyl-2-arachidonoyl-sn-glycero-3-PC (18:0/20:4ω6cis PC), 1-stearoyl-2-docosahexaenoyl-sn-glycero-3-PC (18:0/22:66ω3cis PC), and (ii) bilayers of diacylglycerolipid (DG) molecules with the acyl composition identical to that for PCs. The simulation boxes of the PC bilayers consisted of 96 PC molecules and 2304 water molecules (48 lipid molecules per layer and 24 H2) molecules per lipid). The water was modeled by explicit TIP3P water molecules. The head group of the DG molecules was treated as an effective sphere. The interfaces of each DG bilayer were modeled by flat surfaces; no water molecules were present explicitly in the DG bilayer MD simulation boxes consisted of 96 DG molecules. Mass density profiles along the PC and DG bilayer normal for different groups of atoms were calculated. The computer simulation results are compared to one another, to the available experimental data and to other computer investigations of saturated and unstaturated lipid bilayers.

In this contribution, we report on a study of the self-organization of polynucleotides. The process is computer simulated by the method of molecular dynamics. We investigated a set of polymers composed by one type of nucleotide (the amount of atoms ~3000) as well as a natural molecule phenylalanine t-RNA. Spontaneous transition of α-spiral structure into a globule was observed. In some cases the self-organization was similar to that obtained earlier for simple organic polymers and proteins. Special role of potentials in the self-organization of the polynucleotides was investigated.

In this contribution, we report on a study of the self-organization of polypeptides. The process is computer simulated by the method of molecular dynamics. In a previous work we reported about three types of self-organization observe in our calcuations: stable and unstable globule and 'intermediate' globule. To each type of self-organization corresponds a special type of temperature-time dependence. A new set of self-organization simulations with calculation of drift and vibrational components of atom velocities has provided us an explanation of the obtained results.

In this contribution, we report on a study of the growth of carbon nanotubes. A key factor in molecular dynamics modeling is the choice of interatomic potential. Ab initio molecular dynamics requires extensive computer resources, so that is outside the scope of most complex systems. We have developed simpler molecular dynamics model of charges at bonds which takes into account the electronic and atomic degrees of freedom and which can be implemented using a personal computer. Our approach has the possibility of studying the excited states formed by electronic transitions. The fundamental differnece is that previously one considered only an atomic subsystem whereas now we have investigated both subsystems, atomic and electronic, simultaneously. Our approach was applied to computer simulation of carbon fullerenes and in these paper we introduce results of research formation of nanotubes.

In this contribution we report on the influence of temperature on a fullerene shape. We observed conformation transitions at high temperatures. This phenomenon was discovered with the help of a new molecular dynamics model.

In this contribution we report on a study of structure changes of cyclic hydrocarbon molecule, cyclohexane and two electronic isomers of benzol, in the temperature range from 100° to 1200° C by a new molecular dynamics with charges at bonds. We have also studied time dependence of interatomic distance at these temperatures. It was found that C-(C)-C and C-(C-C)-C interactomic distance can serve as a criterion for conformation transitions between the following confirmations: a boat, a chair, and a new conformation in the form of a propeller. Explanation is based on the theory of stability.

Sputtering of Ni and Ni₃Al(111) surfaces induced by impact of AlN and NiN (N=1÷55) clusters with energies of 500 eV/atom is studied at atomic scale by means of classifical molecular dynamics (MD). The MD code we used implements many-body tight binding potential spliced to ZBL at short distances. We used relatively large computation cells (containing from 32,000 up to 256,000 atoms) with periodic and damped boundary conditions as well as long simulation times (up to 25 ps) and representaive statistics (up to 1000 runs per each case). Total sputtering yields, emission spectrums, and preferential sputtering features are analyzed, both in the linear and non-linear regimes.

Surface binding energy (Us) is a key parameter of any sputtering models as well as comtuer simulation codes (like TRIM or MARLOWE) which are based on the binary collision approximation (BCA). Nowadays, nothing is known about Us values for compound materials and for materials with impurities too. We used atomic scale modeling in frame of classical molecular dynamics (MD) method in order to calculate the surface binding energy values in pure metals, their alloys and for an impurity atom in metallic matrix. Many-body potential based on the second moment approximation of the tight binding model is incorporated into MD code and it allows us to reach realistic values of surface binding energy. Using calculated values of microscopic energetic parameters in BCA models, we can provide consistency between BCA and MD in modeling of linear sputtering phenomena.

Recently various physical phenomena involving nuclear spins in semiconductors attract much attention. The problem is to produce an array of impurity atoms with nuclear spin I=1/2 in the atom matrix wiht I=0, i.e. to produce a nuclear-spin engineered semiconductor heterostructure. Both the concentration and the spatial distribution of impurity should be controlled. It is supposed that utilization of ³¹P atoms as an impurity in ²⁸Si or ³⁰Si matrix possesses significant advantages. Such a structure could be produced by neutron transmutation doping (NTD) of ²⁸Si/³⁰Si/²⁸Si isotopic heterostructure, according to the nuclear reaction ³⁰Si+n→³¹Si(2.6 hour)→³¹P. Computer simulation of the NTD process provides the conditions necessary to create ²⁸Si/³⁰Si:³¹P/²⁸Si heterostructure with good crystal structure and well-defined distribution of impurity concentration. Simulation was carried out using parallel computing capabilities of workstation cluster of AF Ioffe Physico-Technical Institute of the Russian Academy.

Rate equations approach of computer simulation has been applied to investigate the SiC clusters nucleation and growth on Si surface during molecular beam epitaxy. Cluster surface densities have been obtained for a range of temperatures. The temperature influence on the consequent clusters density, including the surface phase transition (which occurs with simultaneous structure reconstruction), has been determined. The results obtained by the application of the suggested physical model have appeared to be in the reasonable agreement with experimental data.

The local irradation and the method of balk photo-e.m.f. measurement were used for a study of irradiation defects in p-type single silicon irradiated with 8 MeV energy electrons. On the basis of experimental and theoretical studies it was concluded that in irradiating p-type silicon with 8 MeV eneryg electrons the share of atomic cascades in radiation damage production begins to prevail over diffusion. Annealing results have shown that in this case it was possible to create tetra vacancies just like the primary defects are formed. Creation of small disordered areas is not excluded.

A model describing the changes of the Curie-Weiss temperature in lead-zirconate thin films under neutron irradiation is proposed. The Curie-Weiss temperature in the irradiated material decreases which is connected to charges caused by neutron irradiation. The charges located near the surfaces due to Schottky effect and in the bulk of the film results in different rates of the Curie-Weiss temperature decreases with neutron fluence. However the influence of the Schottky layers seems to be more pronounced. Satisfactory agreement between the theoretical results and the experimental data is obtained for different neutron fluences.

Bi-substituted ferrite garnet (R Bi)₃(M FE)₅O₁₂ epitaxial films with anomalously high (up to 1.2 deg/μm at RT) specific Faraday rotation provide a unique possibility of magneto-optical imaging of magnetic field microdistributions with a sub-micron resolution close to the diffraction limit. In the present work we give a detailed description of the physical principles and various applications of such films in materials science, microelectronics, magnetic testing and nondestructive evaluation (NDE) of defects in both ferromagnetic and non-ferrous metal components. In the latter case eddy-current excitation is used to reveal flaws, cracks and corrosion. The technique is ideal for not only detailed inspections, but also for rapid scanning over large areas to quickly determine structural condition of the part.

The results of x-ray diffraction analysis of macroscopic stresses in oxide layers and substrate of zirconium alloys are presented in this contribution. Stresses were studied on the tubular specimens of two types of alloys: low tin Zircaloy-4 (Zry-4W) and standard Zircaloy (Zry-4S) which were simultaneously exposed for various time in water with 43 pm O₂ at 360°C. Microstructure characteristics (crystalline size and lattice strains) were evaluated for oxide layers and the metal underlying. Only compressive stresses (up to 1,1 GPz) were determiend in the oxide layers of samples investigated. Only tensile stresses (up to 250 MPa) were determined in metal underlying for all the specimens investigated. The relation between the stress development in oxide layers and kinetics of the alloys investigated was outlined.

The procedure of numerical simulation of near and far fields of diffraction of optical fibers using asymptotic expressions for eigenvalues and eigenfunctions of waveguide modes is considered. The asymptotic expressions suitable for dispersion and polarization effects calculating in step index profiel optical fibers are obatined. The output intensity light profiles are simulated, the statistical properties of distributions are defined and the comparison with experiment is carried out.

Different water disperse systems were studied by integral (spectroturbidemetry) and differential light scattering method with a laser as a source of light. The investigation done concerns the state of kaolin dispersions at storage and under dilution as an example of mineral dispersion systems such as natural water. The role of some light scattering parameters for an optical analysis of water dispersions, like the dispersion of erythrocytes and bacterial cells -Escherichia coli is discussed. The results obtained can help to elaborate the methods for on-line optical control fo natural disperse systems (water, air) with mineral and biological particles.

Different decompositions of large elastoplastic strain on elastic and plastic parts of thermodynamically consistent equations of elastoplasticity are under consideration. It is shown that the values of plastic strains depend on the method of decomposition of elastoplastic strain even for fixed constitutive equations of plasticity and elasticity. Difference of above mentioned plastic strains is investigated analytically and numerically for Mooney elasticity and associate Mises plasticity for special strain: incompressible plane shear and three axial extension.

The subject of interest is the motion of a half space filled by granular medium caused by a normal load applied to its border plane. The process of stresses propagation is represented by Kandaurov model. The mode of standard linear solid is used to take in account the internal friction. The last includes Maxwell and Voigt models of anelasticity. The properties of Kandaurov model simplify the application of the standard linear solid model. The Laplace transforms of vertical displacements of the border plane caused by a constant load are presented as an example in case of axial symmetry.

Dynamics of vertical displacements of a plane bounding a half space filled by Voigt-Kandaurov and Maxwell-Kandaurov media caused by symmetric load is under investigation. The results are obtained for the media possessing the finite values of the sound velocity and of the relaxation times in Voigt's and Maxwell's models of anelasticity.

New standardized, invariant defining equations of thermo-visco-elasticity and criteria of destruction, of fluidity approach and structural transition of reologically complex media based on the concept of endochronic (own, internal) time and equasilinear superposition of mechanical response in its space are considerd. Examples of criteria use corresponding with data of experiment are indicated.

The stress relaxation during the high-rate straining of materials is followed by the energy exchange between macroscopic and mesoscopic scale levels. A correct description of the shock wave propagation in relaxing medium involving the experimentally measured mesoscopic characteristics such as the mass velocity dispersion and the wave amplitude loss on account of irreversible mesostructure formation had been developed on the basis of a new self-consistent non-local hydrodynamic approach. In scope of this theory the problem of the non-steady shock wave propagation in semi-space had been forumulated as a nonlinear operator set with the branching solutions for the mesostructures are responsible for the dynamic behavior of solids as new carriers of deformation. During the stationary wave propagation the macro-meso-energy exchange inside the wave front is reversible. The structure transition to irreversible mesostructures, when medium properties behind the front are considerably changed, can result in a failure of materials.

Cables and tow-lines are often considered as a thread in modeling of various underwater towed systems. Typically, an external load per unit length of the thread in liquid is assumed specified. In the present paper, a new approach to the definition of the hydrostatic load per unit length of the thread is presented. It is shown that the obtained resultant load per unit length of the thread in liquid differs significantly from conventional weight minus buoyancy per unit length of the thread. To demonstrate the influence of the hydrostatic load, several problems are studied. All results are obtained analytically and compared with similar problems under weight less buoyancy of the thread.

The first differential equation of the Rossler model was supplemented by the term that depends explicitly on time. The cosine amplitude defines external action on this dynamical system, and at some value of the amplitude dynamical chaos is possible. Properties of non-autonomous differential equations were investigated by using the standard methods of nonlinear dynamics including the fast Fourier transformation, point maps, phase trajectory projections. The bifurcation cascades were found under variations of the amplitude. The dynamical model presented can be considered as development of the Rossler simple model.

The numerical model FRACSIM developed by the research group in Tohoku University is proven to be an appropriate approximate model of the hot-dry-rock geothermal reservoir capable to address simultaneously the problems associated with hydraulic stimulation, fluid circulation and heat extraction. The structure of the fractured rock is approximated with the network model of fractal geometry. The adopted procedure makes possible to characterize the geothermal reservoirs by parameters measured from the field data. In the present study an improved mathematical model, which accounts for the effect of thermal dispersion on forced convection during the geothermal energy extraction, is proposed. Since the typical flow rate in the fractured reservoir is relatively high, the values of the effective thermal conductivities in the longitudinal and transverse directions are taken to be directly proportional to the values of the fluid velocity. The importance of the thermal dispersion factor for assessment of the total thermal output of the geothermal reservoir is proven.

The cahnges of the stress regime in the natural rocks often cause the fracture shear displacements, which lead (due to fracture surface roughness) to fracture dilation. The simple approach for simulating this natural process is proposed. The method incorporates the experimental measuring of the real fracture surface topography, mathematical modeling of the synthetic fracture lateral slipping (shear dilation). Mathematical model is based on the spectral synthesis method and accounts for the fractal nature of the fracture surfaces. It is shown that the topography of the lengthy fracture surface in the natural rocks can be properly characterized with the data obtained from the small fragments of these surfaces. The algorithm for computing and predicting the fracture dilation and shear dilation angles in the natural rocks as functions of shear offset is proposed.

A computer model of deforming a thin axisymmetric shell in Lagrangian-Euler coordinates under consecutive static and pulse loading was created. Consecutive loading reduces the wedging-out of a formed article and increase the stretching degree at the expense of magnification of deforming a flange folding in drawing. Deformation hardening of a material, elastic unloading, interaction of a shell with a dia, wave character of high-speed deforming and other factors are taken into account. An implicit finite-difference algorithm of a numerical solution, taking into account uniformity both features of statement and solution of two problems, was designed and a program was implemented. Calculations and experiments have shown a possibility of application of the computer model in practice of designing combined drawing.

Recent clinical studies clearly indicate that the resonant frequencies can be used to assess the healing state of a fractured long bone. Although these studies clearly show a certain relation between the resonant frequencies and the stiffness of the bone, the nature of this relation has not yet studied very well. The attempt of considering the locomotion system of a human shank in complex is firstly presented in this paper. The finite element model of the soft and hard tissues composed of the human shank is developed and the vibration numerical analysis is performed. The values of the resonant frequencies for the isolated tibia and for the complex biomechanical system formed by tibia, fibula, achilles tendon and principal shank muscles are obtained during finite element analysis. The obtained result can be used as theoretical fundament to developing low-frequency resonant methods for testing and diagnostics of the physiological conditions of soft and hard tissue during medical treatment and rehabilitation time period after surgery operation.

Structural characteristics of the austenite phase of a NiTi shape memory alloy (SMA) subjected to thermo-mechanical cycling under a constant applied load were studied. Progressive thermo-mechanical action of the external deformation results in both changes of the defect structure and, macroscopically, in memory shape effect degradation. The study was performed using the x-ray method of analysis. Two parameters have been determined to study the evolution of the austenite phase: root-mean-square (RMS) microstrains and coherent block size. the number of thermoa-mechanical loading cycles was varied either from 50 to 400 (for series) or from 1 to 5 for preliminary estimates. Experimental results show that the loading process depends on the changes in the structural cahracteristics. On this basis we propose some structural parameters helpful in the prediction of the memory shape effect degradation in the actuated SMA materials.

Experimental results on the relief dynamics on the loaded Si(111) surface obtained by scanning tunneling microscopy, are presented. Two experimental series are considered: for mechanically and chemically polished surface. Despite the difference of the dynamics scenario in two cases, all effects are essentially surface ones, they arise due to mass redistribution along the surface. As a general framework for consideraiotn we propose the minimum energy principle.

The evolution of plasticity of annealed metallic glass was investigated by microindentation and U-method. Morpholigical features of metallic glass destruction during intendtation were investigated and explained. It was established that for mechanical testing of thin metallic glass, elastic substrates must be used. Mechanical testing mehod of laser treated metallic glass is suggested.

Influence of small doses of x-ray radiation on processes of healing microcrack was investigated. X-ray radiation results in stress relaxation in the tip of cracks for account of reversible motion of dislocations. The intensity of healing and stress relaxation increases with diminishing a wave length of x-rays. The mechanisms of stress relaxation and healing were discussed.

In this report we describe the similarity criterions real objects and models, the possibilities of numerical modeling of gas dynamic processes in the CMM complex of programs developed by us. To describe the volume combustion chamber we use the analytical model of the second range surfaces with the limitations. The algorithm of the modeling program is based on the numerical solution of the full system of nonlinear unsteady equations of dynamics viscid, burning, heat-conducting gas, on the conditions of having diffusion and chemical reactions in two- or three-diemnsional target setting. We look over the building and modification of 2D- and 3D-models of different ranges of complication taking in consideration chemical reactions or not. We compare the results of modeling with the theoretical calculation results and with the experimental data. We also look over the variants to use the results of modeling and the directions of further CMM developemnt.

With the help of algebraic equations it is possible to describe large variety of geometrical surfaces. The algebraic linear equation describes a plane. This equation at any value of factors has the real solution. The algebraic equation of the second degree describes 17 types of surfaces, from which one 5 types imaginery. How many types of a surface can be described by an equation by third and more degrees do not know. For operational use of the description of surfaces with the help of algebraic equations by third and more degrees are necessary for establishing classification of actual surfaces and to determine imaginary areas. In the given activity the methods for realization of such classification and attempt are offered to execute classification for surfaces of the third degree.

The analytical designing composite under the shape of surfaces can be executed by change of values of factors of an algebraic equation circumscribing these surfaces. The more exponent of an equation, the more kinds of a surface it is possible to receive, changing values of factors of an equation. In the given activity the findings of investigation of an algebraic quartic equation obtained by multiplication of the members of two equations of the second degree is resulted. The input equations describe orbs of one size, but displaced in space rather one another. These orbs are intersected. The factors of an equation are adduced to integer values. During research they sequentially decreased per unit of from maximum rating up to null and then up to maximum negative value. The effect of factors on the shape of a surface is shown by the way tables of values of factors of equations and figures of a surface.

Particle systems nowadays are the most popular visualization method for various special effects in 3D computer graphics. Software implementation of a particle system must have an abstract object-oriented model in order to be generic and portable. Besides, for real time graphics it is necessary that the particle system would remain efficient in processor time and memory. Original methods are described in this paper, which allow us to build such systems abstract and generic; as much as possible not depending on software environment and efficient at the same time.

The paper describes a common approach to generation of motion blue effect with particle systems in real time computer graphics. The issue is significant time and memory costs of this effect implementation. Our original method allows us to reduce memory cost, which otherwise may be high especially if there are a few cameras in the system. A basic idea is that instead of storing several previous particle positions they are summed up with some weights and only result is stored.

In this article we formalize and consider the path-planning problem on the weighted graph with prizes (PCPP - prize collecting path-planning). It is generalized travel salesman problem on graph with prizes. We give the formal statement of the PCPP problem and prove that it is NP-hard. We developed the algorihtm to resolve the PCPP problem exactly if graph is a tree and proposed several heuristics based on this algorithm to resolve the problem in common case.