Electron Cotunneling into a Kondo Lattice

Motivated by recent experimental interest in tunneling into heavy electron materials, we present a theory for electron tunneling into a Kondo lattice. The passage of an electron into the Kondo lattice is accompanied by a simultaneous spin flip of the localized moments via cotunneling mechanism. We compute the tunneling current with the large-$N$ mean field theory. In the absence of disorder, differential tunneling conductance exhibits two peaks separated by the hybridization gap. Disorder effects lead to the smearing of the gap resulting in a Fano lineshape.Comment: 4 pages, 2 eps figure

Can Frustration Preserve a Quasi-Two-Dimensional Spin Fluid?

Using spin-wave theory, we show that geometric frustration fails to preserve a two-dimensional spin fluid. Even though frustration can remove the interlayer coupling in the ground-state of a classical anti-ferromagnet, spin layers innevitably develop a quantum-mechanical coupling via the mechanism of ``order from disorder''. We show how the order from disorder coupling mechanism can be viewed as a result of magnon pair tunneling, a process closely analogous to pair tunneling in the Josephson effect. In the spin system, the Josephson coupling manifests itself as a a biquadratic spin coupling between layers, and for quantum spins, these coupling terms are as large as the inplane coupling. An alternative mechanism for decoupling spin layers occurs in classical XY models in which decoupled "sliding phases" of spin fluid can form in certain finely tuned conditions. Unfortunately, these finely tuned situations appear equally susceptible to the strong-coupling effects of quantum tunneling, forcing us to conclude that in general, geometric frustration cannot preserve a two-dimensional spin fluid.Comment: 12 pages, 3 figure

Innovation and Competitiveness in Today’s Technological and Social Transformations

The rapid political and economic changes of recent years and the fourth industrial revolution have opened up new opportunities that are changing the face of the modern economy. At the same time, new risks and threats to the sustainability of development have arisen. In this context, the role of technology and innovation, seen as a factor in the competitiveness of the national economy, requires rethinking. The paper analyses empirical data on the impact of innovation on competitiveness, which led to the conclusion that the influence of this factor has increased, including in the context of the growth of protectionism, the need to move to a model of sustainable development, which requires increased state support for innovation and innovative ecosystems

Realization of the Leadership Potential of Youth in Social and Project Activities

Рассматриваются потенциальные технологии, которые позволят создать формы социальной активности, в которых молодежь будет погружена в особую среду, позволяющую активизировать лидерский потенциал для реализации неиспользуемых резервов социальной системы. В частности, в статье затрагивается понятие социального потенциала, а также упоминается технология развития критического мышления через чтение и письмо, которая может быть включена в модель активизации лидерского потенциала.The article discusses potential technologies that will allow creating forms of social activity in which young people will be immersed in a special environment that allows them to activate leadership potential for the realization of unused reserves of the social system. In particular, the article touches on the concept of social potential, and mentions the technology of developing critical thinking through reading and writing, which can be included in the model of activating leadership potential

The use of modern ICT as tools for development of learning communication in the contemporary university

The article presents a problem-projective study, which is aimed at pedagogical modeling of the introduction modern ICT in the university educational process. The authors explore the idea that the use of modern ICT at the university should ensure the development of a variety of learning communications. This type of complex communications are a cumulative set of methods, channels, techniques, modes and formats for transportation of knowledge that form the information environment of students trainin

Perspectives on retro-tram in tourism

Actualization of cultural heritage based on the nostalgic feeling of the good old days is one of the prospective trends in tourism development in times of crisis. Slowing down the pace of life and time perception are in strong demand due to the overall informatization, growing constraints and risk of uncertainty in the world. The study reveals the factors to manage time perception, describes the concept of the retro style and gives assessment to retro-tram in tourism basing on local and international practices. As a result of the research, the study suggests the concept of the sightseeing retro-tram from the perspectives of the human physiological perception and cultural studies while the results of the cross-case study analysis are summarized as a matrix of managerial recommendations so that to involve it in the tourism industry activities

Effect of mechanical activation on the composition if mineral components in humic acids isolated from carbons

It is shown that the mechanical activation of oxidized and brown coals is accompanied by an increase in the yield of humic acids and in their content of functional groups. It was demonstrated by atomic-emission spectroscopy that, under a high-intensity mechanical treatment, mineral elements are redistributed in the coal substance and incorporated into the structure of humic acids

Impact of magnetic storms on the global TEC distribution

The study is focused on the analysis of total electron content (TEC) variations during six geomagnetic storms of different intensity: from Dstmin = −46&thinsp;nT to Dstmin = −223&thinsp;nT. The values of TEC deviations from its 27-day median value (δTEC) were calculated during the periods of the storms along three meridians: American, Euro-African and Asian-Australian. The following results were obtained. For the majority of the storms almost simultaneous occurrence of δTEC maximums was observed along all three meridians at the beginning of the storm. The transition from a weak storm to a superstorm (the increase of magnetic activity) almost does not affect the intensity of the δTEC maximum. The seasonal effect was most pronounced along the Asian-Australian meridian, less often along the Euro-African meridian and was not revealed along the American meridian. Sometimes the seasonal effect can penetrate to the opposite hemisphere. The character of average δTEC variations for the intense storms was confirmed by GOES satellite data. Though there are some common features of TEC variation revealed during each storm phase, in general no clear dependence of TEC responses on the storm phases was found: the effects were different during each storm at different locations. The behavior of the correlation coefficient (R) between δTEC values along the three meridians was analyzed for each storm. In general, R &gt; 0.5 between δTEC values averaged along each meridian. This result is new. The possible reasons for the exceptions (when R &lt; 0.5) were provided: the complexity of phenomena during the intense storms and discordance in local time of the geomagnetic storm beginning along different meridians. Notwithstanding the complex dependence of R on the intensity of magnetic disturbance, in general R decreased with the growth of storm intensity.</p

Features of shear transformation texture in seamless pipes

Microstructure and texture in seamless 0.08C-Cr-Mo-V, 0.25C-Cr-Mo-V-Nb, 0.08-13Cr-3Ni-Mo-V-Nb, and 18Cr-9Ni steel pipes are studied in the as-rolled and heat-treated states using orientation EBSD microscopy. It has been found that all types of microstructure (ferrite, martensite, and bainite) in products, both after hot rolling and after heat treatment, have well-defined axial crystallographic texture, where the direction is predominately perpendicular to the pipe surface. It is demonstrated that texture formation in heat-treated states is inherited due to the following factors important for the rules of orientation selection during the γ→α phase transformation: 1) occurrence of stable orientation of austenite grains resulted from straining; 2) special misorientation (boundaries) of austenite grains where transformation starts; 3) orientation relationships known for phase transformation; 4) thermal stresses in a product, formed during cooling. The latter can be considered as factor determining special texture in seamless steel pipes. © 2018 Author(s)