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In this paper analytic and invariant solution of the electron motion in crossed electric and magnetic fields where H < E is examined. It is shown that the invariant solution of the proposed problem is formally similar to that of quantum harmonic oscillator. Examining the polarity operator in external field, it is deduced that there is an expression consisting of spin components which remains constant throughout the motion and therefore is integral of motion. Eigenvalues and eigenfunctions corresponding to spin integral of motion are found and analyzed. [ABSTRACT FROM AUTHOR]

The daily activities of two isolated populations of endangered species of rock lizards Darevkia rostombekowi were studied. The main aim of our study was the show the competition among syntopic species of rock lizards. Our results have shown the similarity of patterns of daily activities for lizards belonging to different species and sharing the same territories and differences in peak of their activities, which allow them to avoid the competition. [ABSTRACT FROM AUTHOR]

Some aspects of thermal biology were considered in three species of the lizard genus Darevskia: the parthenogenetic Darevskia armeniaca and D. unisexualis, and their parental bisexual species Darevskia valentini. The main objective of the present research was to compare the thermal biology of these species in a mixed population. Material was captured at four localities in Armenia: Kuchak, Dilijan, Mets Sepasar, and Artavaz in summer 2007, 2013, 2016, and 2018, respectively. Their snout-vent length and cloacal body temperature, as well as air and substrate temperatures were measured. The following differences in the thermal biology of the study species were revealed: D. unisexualis had a relatively low activity temperature range (T = 22.0–32.8°C, vs. 25.6–35.6°C for D. armeniaca or 25.3–35.4°C for D. valentini). The body temperatures of different species were found to correlate differently with both the air temperature and the substrate temperature under the conditions of their coexistence at Kuchak. [ABSTRACT FROM AUTHOR]

The results of the analysis of the genetic variability of parthenogenetic Darevskia rostombekowi (Darevsky, 1957) species using four microsatellite-containing loci are presented. Based on 118 records with geographical coordinates of the presence of this species in Transcaucasia, the maps of potential range were created. The analysis of the genetic structure of populations demonstrated that despite the established multiclonality (seven clonal lines in four populations), D. rostombekowi was formed as a result of a single act of hybridization between closely related bisexual species. The predicted distribution of D. rostombekowi using the modelling of potential range revealed new suitable habitats, where the presence of the species has not been reported previously. The results of this study and the absence of multiple acts of hybridization during the formation of these clones may indicate a regression of population size of the species. Consequently, the estimation of the conservation status of this parthenogenetic species seems to be justified. [ABSTRACT FROM AUTHOR]

Transformation (reflection and transmission) of sound and electromagnetic waves are considered in non-stationary media, properties of which abruptly change in time. Reflection and transmission coefficients for both amplitudes and intensities of sound and electromagnetic waves are obtained. Quantitative relations between the reflection and transmission coefficients for both sound and electromagnetic waves are given. The sum of the energy flux reflection and transmission coefficients for both types of waves is not equal to one (for sound waves it is greater than one). The energy of both waves is not conserved, that is, exchange of the energy occurs between the corresponding waves and medium. As a result, the sound wave obtains a notable property: the transmitting wave carries energy equal to the sum of the energies of the incident and reflected waves. A possibility of the amplification of sound waves and transformation of their frequencies is illustrated. [ABSTRACT FROM AUTHOR]

For the first time the high-energy neutrons scattering in a crystal is considered under the influence of an external laser wave field. The process is inelastic with respect to the laser wave and at the same time it is elastic with respect to a crystal. The possibility of high-energy neutron diffraction is illustrated—wavelength of neutrons is less than the lattice period. The method is based on the multiphoton interaction of the neutron anomalous magnetic moment with the field of laser radiation by using the Farri representation. The neutron-phonon interaction is considered to be a perturbation described by the Fermi pseudopotential. [ABSTRACT FROM AUTHOR]

The fourth order linear differential equation is obtained for the probability density considering the non-Hermitian Hamiltonian (the case of quasistationary states—complexity of energy). Third order nonlinear differential equation for the square of the modulus of the order parameter and for the phase is obtained by making use of Ginzburg–Landau equations. Three integrals of “motion” are found in the absence of the external magnetic field and two integrals are found in the presence of the external magnetic field. The analysis of these integrals is conducted. New analytical solutions are obtained. [ABSTRACT FROM AUTHOR]