Vol 61, No 5 (2018)

This article assesses the impact that the journal has had on the research and development in high-current pulse electronics and electrophysics, gas electronics, physics of gas lasers, relativistic microwave electronics, plasma electronics, etc. All these fields of research involve achievements in three areas of science and technology, namely, the creation of high-power nanosecond pulse generators; fundamental studies of nanosecond high-current discharges in gases, which have led to the discovery of the phenomenon of multielectron initiation of discharges, and studies of pulsed vacuum discharges, which have resulted in the discovery of explosive electron emission. The author began his research activities in these areas in 1958 at Tomsk Polytechnic Institute and continued them at the Institute of High Current Electronics of the Siberian Branch of the USSR Academy of Sciences, which was opened in 1977. A number of articles published in the journal were devoted to priority issues such as the studies of nanosecond discharges in gases, in vacuum, and in water; the description of the properties of explosive electron emission; the invention of metal-dielectric cathodes with ferroelectrics, and the proposal of gas compression in devices based on electrically exploded cylindrical conductors.

Special features of L2₁–(14М)–L1₀ martensitic transformations (MT) are experimentally established for [001]-oriented Ni₅₄Fe₁₉Ga₂₇ (аt.%) single crystals under tensile stress, including staging of superelasticity curves, stress hysteresis, and strain level of martensite formation depending on the test temperature and MT sequence. An additional stage of inelastic strain with high strain hardening coefficient and a stress drop arise on the σ(ε) curves in the interval of changes of the stress-induced MT sequence from L2₁–14M–L1₀ to L2₁–L1₀ (320–400 K) at superelasticity (SE). Special features and physical reasons of this stage and of the stress drop related with the processes of origin and detwinning of L1₀ martensite during stress-induced L2₁–L₁₀ transformation are established. The stage of inelastic strain and the stress drop are absent at the L2₁–14М–L1₀ MT in the [001]-oriented single crystals or at the L2₁–L1₀ MT at other orientations, where detwinning of L1₀ martensite is suppressed by geometrical reasons.

Within the framework of the modified potential cluster model with classification of states according to Young tableaux, the possibility is considered of describing the experimental data on the astrophysical S-factor of radiative p¹⁴N capture to the fourth excited state of the ¹⁵O nucleus with angular momentum 3/2+ at 6.79 MeV.

For a proposed model of decaying dark energy the deflection of light in spherically-symmetric static Gross–Perry spacetime and in Kerr–Taub–Bolt spacetime is considered. Estimates are given for the variation of the standard deflection of light in the field of the Sun.

Perturbation theory and the variational method are used to calculate the ground state energy and the ionization energy of a one-dimensional helium atom. Such an atom can be realized in a superstrong magnetic field.

Results of investigation of regular and chaotic motions of near-Earth asteroids (NEAs) in the vicinity of the 1:2 mean motion resonance with the Earth and 2:1 mean motion resonance with Jupiter are discussed in the present work. The resonant zones, constructed from the set of initial values of the semimajor axis and the mean anomaly at some fixed values of other orbital elements, are numerically simulated. By means of the MEGNO parameter, the vicinities of the boundaries of these zones are investigated. Chaotic zones are represented graphically, and the widths of these zones are numerically estimated. The behavior of the resonant and chaotic zones is demonstrated for different values of the eccentricity and inclination.

Methods of X-ray structural analysis and durometry, as well as electron microscopy were used to identify the stages of mechanical alloying in the case of torsion under high quasi-hydrostatic pressure on Bridgman anvils in the Cu–Zn and Au–Co systems that have different mutual solubility and enthalpy of mixing. It was established that decrease in temperature of mechanical alloying from room temperature (cold deformation) to the boiling temperature of liquid nitrogen (80 К, low-temperature deformation) has a considerable impact on mechanical alloying at different processing stages and on characteristics of an alloy synthesized by deformation. In the Cu–Zn system, when the ratio of powder components corresponds to the solid solution of α-brass in equilibrium state, as deformation increased, one observed consecutive change of evolution stages of the powder mix to the state of copper-based solid solution. At the same time, when processing temperature decreases, larger deformation is required to achieve analogous structural changes. In the Au–Co system characterized by absence of solubility at room and lower temperatures, one also observes the stages of powder mix evolution with the increase in deformation. However, complete dissolution occurs in the case of processing at 80 К, while larger deformation is required in the case of increase in mechanical alloying temperature. The paper examines possible mechanisms of solid solution formation in the system of components that are mutually insoluble under equilibrium conditions.

The paper presents a theoretical research of the shock-induced deformation and fracture of Ni₃Al alloy specimens depending on the type of its stress-strain curves. The modeling of deformation is based on a combination of the approaches of continuum mechanics and dislocation kinetics. The complex model is numerically implemented in a software system RANET-3.

The paper presents the fractal analysis which shows that the distribution or dispersion of 2D nanofiller (graphene oxide) particles in the polymer matrix of nanocomposite determines the critical index in the percolation model of nanocomposite reinforcement. The structure of the particle network or tactoidal aggregates of 2D nanofiller is connected with the finite structure of nanocomposite as a whole and also with the interface effects occurred. Correctness of proposed approach shows good agreement between theoretical calculations and experimental data.

As a result of analysis of the high-resolution Fourier spectrum, the parameters of the effective Hamiltonian for the (010) state and the dipole moment of the v₂ band of the H₂S molecule are determined.

It is proved that the solution of the quasiclassical kinetic equation for the Bose and Fermi statistics can be represented in general in the approximation of the relaxation time. Thanks to the found general solution for the distribution function f(r, p, t), any nonequilibrium characteristic of metals, magnets, and dielectrics can be calculated in any order of perturbation theory in the approximation of the relaxation time τ.

An analytical expression is derived for the energy of a three-component electron-hole liquid (EHL) in a magnetic field. Results of calculations of the EHL properties in Si/Si_1–xGe_x/Si quantum wells are presented. The influence of the magnetic field on the EHL properties and stability depending on the germanium concentration in the SiGe layer is revealed. It is found that the equilibrium electron-hole pair density strongly increases with the magnetic field. It is shown that the dependences of the filling factors of the Landau levels on the magnetic field are shaped as plateaus.

Gains of lasers with regular polygon cross sections of tubes are considered. Results obtained demonstrate the consistency of the model.

Based on a numerical solution of the Boltzmann equation and the equation for charging monodisperse macroparticles, the influence of dust on the electron-transfer coefficients is investigated in a weakly ionized plasma within the range of the reduced-field values E/N = 5·10⁻¹⁸–1·10⁻¹⁵ V·cm2 and dust parameters nd a² = 10⁻⁴–5·10⁻³ cm⁻¹. It is shown that in the region of small values of E/N the diffusion and mobility coefficients in the argon plasma increase upon addition of dust, given the invariable reduced-field value. The effect is accounted for by the presence of a Ramsauer minimum in the transport cross-section of particle collisions. For the discharge in helium, the deviations in the transfer coefficients after the introduction of dust are less pronounced. The presence of dust changes the structure of the electron energy loss during collisions – the fraction of inelastic loss becomes essential in the entire range of the E/N values.

A comparative investigation of the influence of thermomechanical treatment modes on the structural-phase state and mechanical properties of a V–Cr–Zr–Ta low-activation vanadium alloy is performed. It is demonstrated that the use of thermomechanical treatment improves the level of short-term strength at room and elevated temperatures. The alloy is characterized by high ductility in a wide range of temperatures irrespective of the regimes of thermomechanical treatment. It is found out that the V–Cr–Zr–Ta alloy possesses higher thermal microstructure stability and mechanical properties compared to those of the V–Ti–Cr alloys.

The results of studying electrical and gas sensitive characteristics of H₂ sensors based on thin nanocrystalline SnO₂ films with the Pt, Pd, and Ag dispersed layers deposited on the surface and Ag, Y, and Ag + Y additives in the volume are presented. It is shown that various combinations of catalysts on the surface and in the volume have a significant effect on the microstructure of films and density of oxygen adsorption sites on the surface of tin dioxide. As a result, the resistance values of sensors in clean air R₀, activation energies of the temperature dependences of R₀, responses to hydrogen in the concentration range of 50–2000 ppm are different. Studies performed by the method of UV-visible spectroscopy revealed in the absorption spectra of films with a silver addition in the volume a band of surface plasmon resonance of silver indicating that the additive is present in the form of metallic Ag nanoparticles. Particular attention was paid to the influence of long-term tests on the properties of sensors with the listed additives. It was established that the joint introduction of Ag+Y into the volume of films prevents the increase of the resistance and responses during prolonged exposure to hydrogen, which is observed during the operation of all other samples studied. Possible mechanisms for changing the sensors’ properties during testing and the role of additives in their stabilization are considered.

A method of finding all test pairs for robust testable Path Delay Faults (PDFs) is suggested. In foreign literature, the authors find only one or several subsets of the test pairs. In this paper, the test pairs are formed from sequential sets and represented compactly by the Reduced Ordered Binary Decision Diagram (ROBDD). In this paper, the test pairs are formed from adjacent test patterns. All such test pairs are compactly represented by the ROBDD. Having got all test pairs for a path, we may derive a test sequence detecting the robust PDFs of the path in sequential circuits without using Scan techniques. In addition, having got the above-mentioned ROBDDs for a set of paths, we may find compact test sets for the Scan techniques oriented to decreased power consumption during testing. Finding all test pairs is reduced to deriving a Boolean difference for the path considered. The Boolean difference is obtained by applying operations on ROBDDs involved from the combinational part fragments of a sequential circuit. The Boolean difference is also represented by the ROBDD.