Effect of the structure of a complex network on the properties of the dynamical processes on it

The effect of the structure of a complex network on the properties of an avalanche dynamical process on it has been studied. It has been found that such a structural characteristic of the network as the degree of its assortativity (disassortativity), which is numerically expressed by the assortativity coefficient r, is a control parameter determining the properties of the dynamical process on the network.     

Assortative and disassortative networks. The effect of the topology of a complex network on the properties of dynamical processes on it

The effect of the structure of a complex network on the properties of avalanche dynamical process on it has been analyzed for the first time. It has been shown that the assortativity (disassortativity) degree, which is a structure characteristic of the network and is numerically characterized by the assortativity coefficient r, is a control parameter governing the properties of the dynamical process on the network. The structure of individual avalanches on networks with various r values has been studied. It has been shown that the number of nodes involved in an avalanche is a periodic function of the time.     

Influence of the electric potential on the plastic deformation of conductors

The influence of the electric potential on the creep rate of metal conductors has been investigated. The factors responsible for the variation in the creep rate have been revealed. It has been shown that the electric field localized in a double layer on the surface of the charged conductor leads to lowering the potential barrier separating the elastically and inelastically deformed states.     

To the theory of adsorption on epitaxial graphene: Model approach

A model of adsorption on epitaxial graphene has been constructed in two stages: first, the density of states of a graphene monolayer adsorbed on a solid substrate has been found and then an adsorbed atom has been placed on the epitaxial graphene thus formed. Metallic and semiconductor substrates have been considered. Charge transfer between the adatom and epitaxial graphene has been calculated. The roles of the substrate and graphene layer in the formation of the electronic state of adatoms have been estimated.     

Two-stage crystallization on the surface of smectic nanofilms

The influence of the surface and finite size on crystallization in nanofilms of a smectic C liquid crystal with thicknesses between two and several tens of molecular layers has been studied. Transitions in a single surface molecular layer have been detected by optical methods. It has been found that transitions on the film surface take place at a temperature 8°C higher than the crystallization temperature in a bulk sample. Two-stage crystallization has been detected in surface layers where the surface induces a transition to an intermediate structure different from the structure of the phases of the bulk sample.     

Influence of the external mechanical load on the formation of nanopores in an optical fiber under pulsed UV light

The joint action of an external tensile mechanical stress applied to a fiber and high-power UV light pulses on a photosensitive optical fiber has been investigated. The mechanism of formation of fiber Bragg gratings of the type IIA in photosensitive optical fibers has been revealed, and a theoretical model of their formation has been constructed. This mechanism has been confirmed by a series of experiments on the formation of fiber gratings. It has been established that the actions of UV light pulses on stressed and unstressed fibers differ fundamentally. The critical value of the tensile stress of the fiber at which structural defects intensively nucleate in the fiber under the joint action of the irradiation and external load has been determined. This stress coincides with the breaking stress in our experiments.     

Influence of burrowing the atoms on the density of the Fe and Co nanoclusters on the Cu(100) surface

The dependence of the density of the Co and Fe clusters on the Cu(100) surface on the substrate temperature and the deposition flux of the atoms has been studied by the molecular dynamics method and the kinetic Monte Carlo method. It has been shown that burrowing the impurity atoms into the first substrate layer can considerably increase the density of nanoclusters. The influence of burrowing the atoms on the size distribution of nanoclusters has been investigated.     

Influence of three-dimensional inhomogeneities of the magnetic parameters on the dynamics of vortex-like domain walls

The interaction of a vortex-like domain wall moving in an external magnetic field with a three-dimensional periodic chain of cubic volumes with high values of the saturation magnetization and magnetic anisotropy constant has been investigated theoretically. It has been found that the result of the interaction depends on the initial distance between the wall and the region of inhomogeneity of magnetic parameters at the moment of turning on the external magnetic field. The pinning of domain walls near the regions with high values of the saturation magnetization and magnetic anisotropy constant has been investigated, and the anisotropy of the corresponding depinning fields has been revealed. The method of investigation is the numerical micromagnetic simulation.     

A study of the Millepede alignment algorithm on the Monte Carlo model of the HERA-B outer tracker

In this paper a method of internal alignment of HERA-B OTR PC chambers is discussed. The method is based on a simultaneous fit of the track and alignment parameters, using Millepede matrix reduction and singular value decomposition. Software implementing this idea has been developed, and the method has been studied on Monte Carlo models with different levels of simulation. A generalization of this method for the case of the nonlinear track model has been proposed. The text was submitted by the authors in English.     

Influence of the polarization of radiation on the shape of resonances of coherent population trapping on fine-structure levels

The dependence of the shape of resonances of coherent population trapping (CPT) on magnetic sublevels of thallium atoms, forming a generalized Λ-system with the magnetic sublevels of the fine-structure levels as lower ones, on the polarization of the radiation fields has been numerically studied. The cases of linear, elliptical, and circular polarizations have been considered. The shape and the number of CPT resonances for different polarizations have been compared. It has been concluded that the electromagnetically induced transparency can be changed by changing the polarization properties of the laser radiation. The possibility to decrease the number of observed resonances may be useful in high-resolution spectroscopy.     

Effect of sediment formation on the filtration of a liquid from suspension

The problem of the gravitational filtration of a liquid in suspension is considered taking into account the formation of deposition by sedimentary disperse particles. The behavior of the suspension has been described using the system of equations of 1D inertia-free motion of a two-phase mixture, while the flow of the liquid through the porous sediment layer has been described by the filtration equation based on the Darcy law. The dynamics of sediment formation has been analyzed. Limiting cases of equidense and equilibrium suspensions have been studied separately. The expressions for integrated characteristics of the filtration of a disperse mixture in the gravity field have been derived, and the intensities of filtration in different regimes have been compared. The effect of key parameters on the dynamics of filtering a liquid from a suspension has been investigated.     

On the accuracy of the ray-tracing algorithms based on various sound receiver models

In this paper, the effect of sound ray detection on the accuracy of sound field simulation by using the ray-tracing technique has been discussed. The current methods to define the receiver size have been briefly described. Then a new equation for the computation of the size of a receiver has been proposed and it has considered such factors as the size of the room, the number of initial rays and the distance from source to receiver. The corresponding algorithm has been compared with two other algorithms that are based on different receiver models. It can be concluded from the computed and measured results that the new model is applicable for more extensive situations.     

Effect of low electrical potentials on the microhardness of metallic materials

The effect of low (<5 V) electrical potentials on the microhardness of metallic materials has been studied experimentally. It has been revealed that this effect does depend on the sign of the electric field potential. It has been found that the microhardness of aluminum, cobalt, and zinc decreases and the microhardness of zirconium and iron increases when an electrical potential is applied. It has been argued that the degree of microhardness change under an electric field depends on the magnitude of applied potential, the magnitude of the Hall coefficient of a metal, and its physicochemical properties.     

Effect of the integrated time of the induced current signal on the position resolution of the RPC detector

A prototype RPC with position resolution less than 1 mm has been produced and studied. Based on this RPC detector, the effect of the width of the integrated FADC time window on the position resolution of a RPC has been studied experimentally and theoretically. The results of theoretical calculation and experimental measurement have shown good agreement.     

Effect of the gas density on the force action of a turbulent jet

We have reported on the results of experimental and theoretical studies of the effect of the gas density on the force action of a gas jet for the flow parameters monitored by the pressure upstream of the outlet aperture. No appreciable effect of density has been revealed. At attempt has been made to describe the dependence of the force of action of the jet on the pressure upstream of the outlet aperture using isentropic expressions. It has been found that the only parameter of the gas that can affect the force action of the jet is the adiabatic exponent.     

Effect of the integrated time of the induced current signal on the position resolution of the RPC detector

A prototype RPC with position resolution less than 1 mm has been produced and studied. Based on this RPC detector, the effect of the width of the integrated FADC time window on the position resolution of a RPC has been studied experimentally and theoretically. The results of theoretical calculation and experimental measurement have shown good agreement.     

New experiment on the observation of the effect of accelerating matter in neutron optics

The results of a new experiment on the observation of the effect of accelerating matter in neutron optics are reported. It has been shown that the velocity of neutrons periodically varies when they pass through a harmonically moving refractive sample. The idea of the experiment is based on time focusing, i.e., on the fact that the periodic modulation of the velocity of neutrons leads to the oscillation of the flux density at the observation point. The magnitude of the effect is in reasonable agreement with the theoretical predictions. The experiment has been carried out with ultracold neutrons and a change of ±1 cm/s has been detected in the neutron velocity.     

Mobility of vacancies under deformation and their effect on the elastic properties of graphene

The effect of isolated vacancies on the elastic properties of a graphene sheet has been investigated by the ab initio density functional method. An almost inverse linear dependence of the Young’s modulus on the concentration of vacancies has been revealed. The height of potential barriers for the motion of vacancies in various directions has been calculated as a function of various independent applied strains. The velocity of vacancies at various temperatures has been calculated as a function of applied strains using the transition state theory.     

Calorimetric studies of a quasi-liquid layer on the surfaces of ice granules

The calorimetric studies of a quasi-liquid layer on the surface of ice have been performed. The activation energy in the thermal generation of the quasi-liquid layer has been determined. The gravitational draining of the quasi-liquid layer over an ice surface has been detected. The transition of the quasi-liquid layer to granules of a hydrophilic material, which is accompanied by the energy release, has been revealed.     

Effect of Pump Depletion on the Spectrum of Twin Beams

The effect of pump depletion on the spectrum of twin beams, which appear in the process of collinear parametric down-conversion in a nonlinear crystal with an aperiodic domain structure and have a high degree of simultaneity, has been described. A system of equations describing the interaction of pump with all modes of scattered light simultaneously has been derived. It has been shown that pump depletion results in a noticeable broadening of the spectrum of twin beams for a quadratic-hyperbolic law of variation of the reciprocal lattice vector of the domain structure. The effect of narrowing of the coherent peak in the sum-frequency generation signal from twin beams has been demonstrated. This effect increases as the pump is depleted.