Electron mobility on a surface of dielectric media: influence of surface level atoms

We calculate the contribution to the electron scattering rate from the surface level atoms (SLA), proposed in [A.M. Dyugaev, P.D. Grigoriev, JETP Lett. 78, 466 (2003)]. The inclusion of these states into account was sufficient to explain the long-standing puzzles in the temperature dependence of the surface tension of both He isotopes and to reach a very good agreement between theory and experiment. We calculate the contribution from these SLA to the surface electron scattering rate and explain some features in the temperature dependence of the surface electron mobility. This contribution is essential at low temperature $T<0.5$ when the He vapor concentration is exponentially small. For an accurate calculation of the electron mobility one also needs to consider the influence of the clamping electric field on the surface electron wave function and the temperature dependence of the He3 chemical potential.Comment: 6 pages, 1 figur

Of professional future of vocational pedagogical university’s students

The article describes the features of professional identity and forecasting of professional future for bachelors of vocational trainingРаскрываются особенности профессиональной идентификации и прогнозирования профессионального будущего у бакалавров профессионального обучени

The problem of forming time transspektive professional development of future specialists in modern conditions

The article deals with the concept of "individual time transspective" in the context of the professionalization of the individual. The author proves the necessity to study student?s professional transspective. There were allocated individual time distortions of transspective of professional development: decenteration in the past and the future, contraction of perspective, discrete transspective and its splitting in the allocation of alternative options for professional developmentВ статье раскрывается понятие «индивидуальная временная трансспектива» в контексте профессионализации личности. Обосновывается необходимость изучения профессиональной трансспективы у учащихся профессиональной школы. Выделены искажения индивидуальной временной трансспективы профессионального становления: децентрации в прошлое и в будущее, укорочение перспективы, дискретность трансспективы и ее расщепление в процессе выделения альтернативных вариантов профессионального развити

Sentinel headache as a warning symptom of ischemic stroke

Background: There are no previous controlled studies of sentinel headache in ischemic stroke. The purpose of the present study was to evaluate the presence of such headache, its characteristics and possible risk factors as compared to a simultaneous control group. Methods: Eligible patients (n = 550) had first-ever acute ischemic stroke with presence of new infarction on magnetic resonance imaging with diffusion-weighted imaging (n = 469) or on computed tomography (n = 81). As a control group we studied in parallel patients (n = 192) who were admitted to the emergency room without acute neurological deficits or serious neurological or somatic disorders. Consecutive patients with stroke and a simultaneous control group were extensively interviewed soon after admission using validated neurologist conducted semi-structured interview forms. Based on our previous study of sentinel headache in transient ischemic attacks we defined sentinel headache as a new type of headache or a previous kind of headache with altered characteristics (severe intensity, increased frequency, absence of effect of drugs) within seven days before stroke. Results: Among 550 patients with stroke 94 patients (17.1%) had headache during seven days before stroke and 12 (6.2%) controls (p < 0.001; OR 3.9; 95% CI 1.7-5.8). Totally 81 patients (14.7%) had sentinel headache within the last week before stroke and one control. Attacks of arrythmia during seven days before stroke were significantly associated with sentinel headache (p = 0.04, OR 2.3; 95% CI 1.1-4.8). Conclusions: A new type of headache and a previous kind of headache with altered characteristics during one week before stroke are significantly more prevalent than in controls. These headaches represent sentinel headaches. Sudden onset of such headaches should alarm about stroke. © 2020 The Author(s)

Fast diffusion of graphene flake on graphene layer

Diffusion of a graphene flake on a graphene layer is analyzed and a new diffusion mechanism is proposed for the system under consideration. According to this mechanism, rotational transition of the flake from commensurate to incommensurate states takes place with subsequent simultaneous rotation and translational motion until the commensurate state is reached again, and so on. The molecular dynamics simulations and analytic estimates based on ab initio and semi-empirical calculations demonstrate that the proposed diffusion mechanism is dominant at temperatures T ~ Tcom, where Tcom corresponds to the barrier for transitions of the flake between adjacent energy minima in the commensurate states. For example, for the flake consisting of ~ 40, 200 and 700 atoms the contribution of the proposed diffusion mechanism through rotation of the flake to the incommensurate states exceeds that for diffusion of the flake in the commensurate states by one-two orders of magnitude at temperatures 50 - 150 K, 200 - 600 K and 800 - 2400 K, respectively. The possibility to experimentally measure the barriers to relative motion of graphene layers based on the study of diffusion of a graphene flake is considered. The results obtained are also relevant for understanding of dynamic behavior of polycyclic aromatic molecules on graphene and should be qualitatively valid for a set of commensurate adsorbate-adsorbent systems.Comment: 33 pages, 6 figure

Typology of strategies of personality meaning-making during professional education

The importance of the studied issue is conditioned by the fact that high dynamic of processes in the labour market requires constant work of an individual on self-determination and search for significance of his/her professional activity. The purpose of research is theoretical development and empirical verification of the types of strategies of meaning-making based on perceptions of future in terms of professional self-determination of the personality at the stage of vocational training. Basic research methods: modelling, psychosemantic approach, allowing to perform research process with the possibility of more in-depth analysis of the results. Research results: the model of the semantical future in the consciousness of the personality, which includes affective, cognitive, activity and intentional components is developed and empirically verified; the types of strategies of meaning-making based on perceptions of future in terms of professional selfdetermination of the personality at the stage of vocational training is identified, the typology includes the following 3 types of the meaning-making strategies: strategy of integration of the meaning of education and profession in the model of own future, strategy of disintegration and strategy of uncertainty and delay of the semantical choice. Significance of results: analysis of the semantical grounds for future professional activity will help optimize the training of a competent, competitive and adaptive specialist ready to continuous self-development, and to intensify the process of professional self-determination and building life and professional prospects of the personality at the stage of vocational training, as exactly at this stage the professional competence and identity is built up. © 2016 Shchipanova et al

Catalytic degradation of polyethylene in the presence of synthetic aluminosilicates

Degradation of polyethylene in the presence of synthetic amorphous aluminosilicates as catalysts to form petroleum-like hydrocarbons was studiedyesBS