Vol 60, No 4 (2017)

As a result of analysis of the high-resolution Fourier spectrum of the CH₂=CD₂ molecule, the lines corresponding to the transitions from the vibrational state (ν₁₀ = 1) are discovered and assigned for the first time. The experimental data are used to determine the parameters of the effective Hamiltonian of the molecule.

The approach which combines methods of crystal plasticity and deformable solid mechanics is used to explore the stress-strain state of a heavy-wall pipe made of dispersion-hardened Cu-based alloy and subjected to the uniform internal pressure. The distribution of the deformation and stress along the pipe wall is determined for various pipe geometry. The approximating equations are obtained to determine the yielding area and elastic and plastic strength limits.

The paper deals with the dislocation substructure of polycrystalline FCC alloys modified by plastic deformation at a distance from the area of the specimen fracture. Observations are performed using the transmission electron microscopy. Cu–Al alloys with grain size ranging from 10 to 240 μm are studied in this paper. The parameters of the dislocation substructure are measured and their variation is determined by the increasing distance from the fracture area. It is shown how the grain size influences these processes. The different dislocation substructures which determine the specimen fracture at a mesocscale level are found herein.

Results of investigation into the destruction of Ni₃Ge single crystals oriented along the [001] axis are presented. Dislocation structures and deformation relief after deformation at different temperatures are studied. It is demonstrated that the dislocation structure remains homogeneous in the entire range of anomalous temperature dependence of Ni₃Ge mechanical properties. Transition from brittle to brittle-viscous destruction mechanism is observed with increasing temperature. Zones with completely or partially destructed long range atomic order are formed near the opened crack surfaces.

The paper presents the results of research performed by the modeling method and focusing on the distribution of material and energy flows at the interface of solid and liquid media under non-steady-state conditions. Modeling was performed using the case of two parallel oxidation-reduction reactions that occur under the impact of an external current supply of unlimited power. The identified regularities can be used when designing and arranging specific heterogeneous oxidation-reduction processes, in order to arrange local energy impact, including when one needs to form the nano-structured non-metallic inorganic coatings by microplasma method. Modeling demonstrates that nanosized localization of high-energy flows is possible at the media interface. Depending on pulse duration, the instantaneous energy can exceed the bond energy of chemical compounds. The identified regularities are true for description of non-steady-state heterogeneous oxidation-reduction reactions in chemistry, electrochemistry, catalysis and other areas of science and technology.

Using transmission electron microscopy and X-ray diffraction analysis, the structural-phase state of steel 0.1C–2V–1Ti–Fe, deformed by the SPD methods and subjected to high-temperature annealing at the temperatures 600 and 700°С, is investigated. The influence of the steady temperature on the grain size, steel phase composition, carbide transformations, carbide particle size and distribution density, carbon distribution, and fine-structure parameters are determined. A special focus is made on the sources of internal stress.

Numerical value of the shear zone diameter is refined. It is assumed that the shear zone is bounded by long strong dislocation barriers formed in the course of reaction between glissile dislocation segments of the loop and dislocations of non-coplanar sliding systems. Based on the modified model of inter-dislocation contact interactions, the mean free path and the probabilities of occurrence of long strong junctions formed by arbitrary components of the dislocation loop are determined. Results are obtained for different orientations of the crystal deformation axes.

Hadrons and multiquark states are discussed within the context of holographic quantum chromodynamics. This approach is based on an action that describes the hadron structure with breaking of conformal and chiral symmetry and includes confinement through the presence of a background dilaton field. According to gauge/gravity duality, five-dimensional boson and fermion fields, moving in AdS space, are dual to the four-dimensional fields on the surface of the AdS sphere, which correspond to hadrons. In this framework, the hadron wave functions – the building blocks of the hadron properties – are dual to the profiles of the AdS fields in the fifth (holographic) dimension, which is identified with a scale. As applications, we consider the properties of hadrons and multiquark states.

On the basis of a scalar potential associated with Beltrami’s geometry – manifolds of constant negative curvature, the Klein–Gordon problem has been solved, making it possible, under the assumption of a physical structure of the fifth dimension (presumably a rich form of matter), to model on the basis of the Kaluza–Klein theory the hypothesis of decaying dark energy configuring the rates of expansion of the Universe.

Results of investigation into the resonant structure of perturbations and long-term orbital evolution of space vehicles of GLONASS and GPS global navigating satellite systems (GNSS) under assumption that all of them have lost control on 08/01/2015 are presented. It is demonstrated that the majority of the examined objects are in the range of action of the secular resonances of various types. In addition, practically all satellites of the GPS system are within the scope of the 2:1 orbital resonance with rotation of the Earth. Results of the MEGNO analysis demonstrate that the motion of all objects of the GLONASS system during the 100-year period is regular, whereas the motion of the majority of objects of the GPS system is subject to chaotization.

Mechanical and thermogravimetric properties of polymer composite materials with various concentrations of multiwalled carbon nanotubes effectively shielding radiation in the radio frequency (20 Hz – 1 MHz) and microwave (26–36 GHz) frequency ranges are studied. As a matrix, widely available polymeric materials, such as polyvinyl acetate and styrene-acrylate, were used in the form of dispersions. From the analysis of the obtained experimental data, it was shown that the introduction of carbon nanotubes into the polymer matrix makes it possible to increase mechanical properties and thermal stability of composite materials.

The problem of the gauge dependence of the effective field is considered within the framework of the method of the functional renormalization group for general gauge theories.

Using optical and chemical processes, the composition of the products of decay of the atmospheric-pressure non-equilibrium plasma is determined in a pulsed, high-voltage discharge in the modes of apokampic and corona discharges. It is shown that the products of decay primarily contain nitrogen oxides NO_x, and in the mode of the corona discharge – ozone. Potential applications of this source of plasma are discussed with respect to plasma processing of the seeds of agricultural crops.

The results of experimental measurements in the frequency range 10 kHz – 1 GHz of the complex dielectric permittivity of quartz granule powders of various sizes moistened with distilled water and a salt solution are presented. On the basis of these results, a relaxation model has been constructed that makes it possible to separate the influence of relaxation processes caused by polarization of the water–mineral and water–air interfaces on the complex dielectric permittivity. The model parameters are found for various granule sizes and solution concentrations. It is shown that the relaxation time of both processes decreases with decreasing granule size and increasing the concentration of the solution. A different character of the dielectric permittivity hysteresis at different frequencies with a decrease/increase in the water saturation coefficient is explained. The prospects of using the dielectric method for determining the petrophysical characteristics of rocks are discussed.

The effect of the electrode shapes on the pump discharge width and the energy of radiation of the KrF laser with pulse duration of 30 ns is investigated by the method of computer modeling. The pump and laser power density distributions across the discharge cross section are obtained as functions of the electrode curvature radii. It is shown that an optimum is observed in the dependence of the laser radiation energy on the electrode radius given that the excitation parameters and the mixture composition remain unchanged. The optimum is reached with the electrodes for which the maximum excitation power density in the discharge does not exceed 8 MV/cm³.