Giant Magnetoresistance Oscillations Induced by Microwave Radiation and a Zero-Resistance State in a 2D Electron System with a Moderate Mobility

The effect of a microwave field in the frequency range from 54 to 140 $\mathrm{GHz}$ on the magnetotransport in a GaAs quantum well with AlAs/GaAs superlattice barriers and with an electron mobility no higher than $10^6$ $\mathrm{cm^2/Vs}$ is investigated. In the given two-dimensional system under the effect of microwave radiation, giant resistance oscillations are observed with their positions in magnetic field being determined by the ratio of the radiation frequency to the cyclotron frequency. Earlier, such oscillations had only been observed in GaAs/AlGaAs heterostructures with much higher mobilities. When the samples under study are irradiated with a 140-$\mathrm{GHz}$ microwave field, the resistance corresponding to the main oscillation minimum, which occurs near the cyclotron resonance, appears to be close to zero. The results of the study suggest that a mobility value lower than $10^6$ $\mathrm{cm^2/Vs}$ does not prevent the formation of zero-resistance states in magnetic field in a two-dimensional system under the effect of microwave radiation.Comment: 4 pages, 2 figur

Tunneling between 2D electron layers with correlated disorder: anomalous sensitivity to spin-orbit coupling

Tunneling between two-dimensional electron layers with mutually correlated disorder potentials is studied theoretically. Due to this correlation, the diffusive eigenstates in different layers are almost orthogonal to each other. As a result, a peak in the tunnel I-V characteristics shifts towards small bias, V. This "protects" the peak against the interaction-induced smearing, since the relaxation rate near the Fermi level is low. If the correlation in disorder potentials is complete, the peak position and width are governed by the spin-orbit coupling in the layers; this coupling lifts the orthogonality of the eigenstates. Possibility to use inter-layer tunneling for experimental determination of weak intrinsic spin-orbit splitting of the Fermi surface is discussed.Comment: 5 pages, 5 figures; published version, minor change

Fractional quantum Hall effect without energy gap

In the fractional quantum Hall effect regime we measure diagonal ($\rho_{xx}$) and Hall ($\rho_{xy}$) magnetoresistivity tensor components of two-dimensional electron system (2DES) in gated GaAs/Al$_{x}$Ga$_{1-x}$As heterojunctions, together with capacitance between 2DES and the gate. We observe 1/3- and 2/3-fractional quantum Hall effect at rather low magnetic fields where corresponding fractional minima in the thermodynamical density of states have already disappeared manifesting complete suppression of the quasiparticle energy gaps.Comment: 4 pages, 4 figure

Pedagogical conditions of primary drug abuse prevention among students of a higher education institution

The relevance of the researched problem is caused by the fact that being one of the least adapted and socially unprotected groups, young people bear the impress of general social uncertainty, lack of confidence and uneasiness, as a result of it, drug addiction problems among young people are pushed into the forefront among social-pedagogical and psychological-pedagogical problems. The purpose of the presented article consists in theoretical reasons, development experimental and research check of a complex of the pedagogical conditions providing efficiency of primary prevention of drug addiction among students of a higher education institution. The leading method to a research of this problem is the modeling method that enables to consider this problem as a purposeful and organized process of creation of the pedagogical conditions necessary for effective primary prevention of drug addiction among students of a higher education institution. The complex of the pedagogical conditions providing efficiency of process of primary drug abuse prevention is presented in the article. It consists of the pedagogical analysis of the reasons of a drug abuse, detection of specifics of a drug abuse of youthful age, the choice and use of the methods and agents of primary prophylaxis of a youth drug abuse, development of a special course for training of specialists which are carrying out activities for prophylaxis of the drug habit at educational organizations. The complex of pedagogical conditions is focused on the process organization of drug abuse prevention among students and focused on development of methodical ensuring process of training of the teachers who are carrying out activities for drug abuse prevention in educational organizations. The materials of article can be useful to teachers of higher education institutions and colleges participating in the organization and carrying out preventive measures of a drug addiction, and also to the listeners, graduates of military academies, and practical staffof Department of Internal Affairs of the Russian Federation who are interested in drug addiction problems. © Authors

Magnetoresistivity in a Tilted Magnetic Field in p-Si/SiGe/Si Heterostructures with an Anisotropic g-Factor: Part II

The magnetoresistance components $\rho_{xx}$ and $\rho_{xy}$ were measured in two p-Si/SiGe/Si quantum wells that have an anisotropic g-factor in a tilted magnetic field as a function of temperature, field and tilt angle. Activation energy measurements demonstrate the existence of a ferromagnetic-paramagnetic (F-P) transition for a sample with a hole density of $p$=2$\times10^{11}$\,cm$^{-2}$. This transition is due to crossing of the 0$\uparrow$ and 1$\downarrow$ Landau levels. However, in another sample, with $p$=7.2$\times10^{10}$\,cm$^{-2}$, the 0$\uparrow$ and 1$\downarrow$ Landau levels coincide for angles $\Theta$=0-70$^{\text{o}}$. Only for $\Theta$ > 70$^{\text{o}}$ do the levels start to diverge which, in turn, results in the energy gap opening.Comment: 5 pages, 6 figure

Educational and cognitive independence of students in e-learning

Topicality of the topic is driven by the changed social and economic conditions in Russia, that led to the search for educational paradigms adequate to the new social and economic development of the country, and by the rapid growth of the role of information technologies as well as by the need to improve the professionalism of teachers in their use of computer technologies in education. The aim of the article is to draw the attention of the pedagogical community to the actual forms of e-learning in modern educational practice of Russian education. The leading approach to the study of this problem is the analysis of world and Russian experience of using e-learning in order to strengthen the independence of students. The recommendations on the implementation of e-learning in the context of Russian education were suggested as the result of the research. The material of the article can be useful for teachers seeking to apply modern methods and technologies of teaching. © Authors

Issues of financial assurance of economy greening in the regions

The relevance of the analyzed issue is caused by the need to internalize environmental externalities in the modern world. The purpose of the article is to examine the issue of financial support of the green economy using the example of the regions included in the Volga Federal District (VFD). The leading methods to the study of this issue is a comparative analysis of environmental taxes and charges in Russia and countries of the European Union (EU) and the analysis of environmental problems in the regions of the Volga Federal District, which allow identifying the shortcomings of the existing environmental payment system and proposing measures to modernize the system of financial support of the green economy. The key shortcomings of the existing environmental payment system: low rates of environmental payments; the inappropriate use of funds received from environmental payments; concentration of 97% of revenues from environmental payments in the federal budget. The contents of the article may be helpful for public authorities of general and special competence to develop the principal directions of environmental policy and plan activities aimed at improving the green economy. © 2016 Shekhova et al

The experience of positioning the university at the educational services market

The relevance of the problem under study is based on the necessity to find the most productive method of positioning a higher educational organization at the educational services market within the conditions of transfer from the centrally planned economy to a market economy and changing of the thinking format of the young generation. The purpose of the article is to develop a set of marketing actions for positioning a higher educational organization at the educational services market and its assessment. The lead method of studying this problem is modeling which provides the possibility to consider the problem as a process of results-oriented and well-informed managing of the process of development of a university as an educational system. The article contains a set of marketing actions aimed at positioning the university at the educational services market using the organization’s own internal resources and consisting of the interconnected components, such as motivational-target, content-processing and resultassessing; their specific features are described and the algorithm of implementing this set is developed. The developed and assessed system is intended for promotion of the university as a brand at the educational services market, for strengthening and reinforcing its competitive positions and increasing the university’s attractiveness for future students. The materials of the article can be useful for education specialists oriented towards marketing of educational services, for teachers who deliver a course of lectures in disciplines related to pedagogical marketing or marketing of educational services. © 2016 Dorozhkin et al

Peculiarities of students of pedagogical specialties training in preventive work with juveniles delinquents

The relevance of the problem under investigation is due to the high significance of preventive work with juvenile delinquents to society. The article aims to study the problems arising while developing students' competencies in professional activities for the prevention of the infringing behavior of juvenile delinquents, as well as the identification of specific historical and socio-cultural conditioning of the criminalization of youth environment. The leading method to the study of this problem is the analysis and synthesis of experience in teaching students of pedagogical specialties skills for crime prevention and the illegal behavior of juveniles; this method allows us to identify ways to enhance students' learning qualities for this kind of activity. Research results: the methodological approaches for teaching students the skills of preventive work with juveniles delinquencies were developed; the analysis of socio-cultural causes of juvenile delinquency and their effect on the prevention work was carried out; recommendations to improve the effectiveness of pedagogical preventive work with juvenile offenders and specification of features and methods of teaching this kind of activity were formulated. The article can be useful for the practical work of teachers, social workers, law enforcement officers and all those who, one way or another connected with the work on the prevention of crime and the illegal behavior of underage. © 2016 Moskalenko et al