Wave packet dynamics in a monolayer graphene

The dynamics of charge particles described by Gaussian wave packet in monolayer graphene is studied analytically and numerically. We demonstrate that the shape of wave packet at arbitrary time depends on correlation between the initial electron amplitudes $\psi_1(\vec r,0)$ and $\psi_2(\vec r,0)$ on the sublattices $A$ and $B$ correspondingly (i.e. pseudospin polarization). For the transverse pseudospin polarization the motion of the center of wave packet occurs in the direction perpendicular to the average momentum ${\vec p_0}=\hbar \vec{k_0}$. Moreover, in this case the initial wave packet splits into two parts moving with opposite velocities along ${\vec p_0}$. If the initial direction of pseudospin coincides with average momentum the splitting is absent and the center of wave packet is displaced at $t>0$ along the same direction. The results of our calculations show that all types of motion experience {\it zitterbewegung}. Besides, depending on initial polarization the velocity of the packet center may have the constant component $v_c=uf(a)$, where $u\approx 10^8 cm/s$ is the Fermi velocity and $f(a)$ is a function of the parameter $a=k_0d$ ($d$ is the initial width of wave packet). As a result, the direction of the packet motion is determined not only by the orientation of the average momentum, but mainly by the phase difference between the up- and low- components of the wave functions. Similar peculiarities of the dynamics of 2D electron wave packet connected with initial spin polarization should take place in the semiconductor quantum well under the influence of the Rashba spin-orbit coupling.Comment: 7 pages, 8 figures, to be published in Phys. Rev.

Psychological and pedagogical technologies for the correction of social fears of participants in a subculture of role-playing games of live action

Purpose of the study is to identify markers, "risk zones" that contribute to deviations among representatives of the subculture "roleviks", to elaborate a technology to correct negative experiences among "role" movement representatives to increase the efficiency of their adaptation. The following research methods were used in this study: “Questionnaire of the hierarchical structure of actual personal fears” (ISAS) methodology to identify phobias; Personality Belief Questionnaire – PBQ to specify dysfunctional beliefs impeding adaptation (emotional well-being, constructive relationships with other people, etc.). The research results suggest that a systematic integrated approach is a necessary condition for the success of the psychological technology aimed at overcoming negative experiences and maladaptation of "role" movement subculture representatives. A combination of diagnostic and correctional models to overcome social fears, deprivation and maladaptation makes up the essence of the technology. The research provides findings that can be used by managers of various levels in the education system, social workers, teachers and practical psychologists in the education system; they can also be of use while organizing special programs for educators, social and psychological services. It has been worked out to help students - “roleviks” to overcome their social fears. It represents a system of single interrelated activities determined to form and develop personal adaptive resources. It has been established that positive changes in adaptation strategies, a decrease in the level of social fears and anxiety are the main criteria for evaluating the effectiveness of the presented psychological-pedagogical technology. It is shown that the applied technology promotes the decrease of experienced fears intensity, forms stress resistance, and contributes to the selection of effective social interaction strategies.The work is performed according to the Russian Government Program of Competitive Growth of Kazan Federal University

Wave packet dynamics in hole Luttinger systems

For hole systems with an effective spin 3/2 we analyzed analytically and numerically the evolution of wave packets with the different initial polarizations. The dynamics of such systems is determined by the $4\times 4$ Luttinger Hamiltonian. We work in the space of arbitrary superposition of light- and heavy-hole states of the "one-particle system". For 2D packets we obtained the analytical solution for the components of wave function and analyzed the space-time dependence of probability densities as well as angular momentum densities. Depending on the value of the parameter $a=k_0d$ ($k_0$ is the average momentum vector and $d$ is the packet width) two scenarios of evolution are realized. For $a>>1$ the initial wave packet splits into two parts and the coordinates of packet center experience the transient oscillations or {\it Zitterbewegung} (ZB) as for other two-band systems. In the case when $a0$ remains almost cylindrically symmetric and the ripples arise at the circumference of wave packet. The ZB in this case is absent. We evaluated and visualized for different values of parameter $a$ the space-time dependence of angular momentum densities, which have the multipole structure. It was shown that the average momentum components can precess in the absence of external or effective magnetic fields due to the interference of the light- and heavy hole states. For localized initial states this precession has a transient character.Comment: 9 pages, 8 gigur

The organization of the rating system for assessing the quality of university students training

In spite the universities use the rating system of assessing for a quite long time, this issue is still not fully considered. The article is based on the position of insufficient state of knowledge of the multifunctionality of the students rating. The rating helps to reveal the potential of students. It is mentioned that the rating system of assessment is a tool that will improve the quality of training and provide the required level of motivation. During the research, the following methods were used: analysis, synthesis, induction, deduction. As a result, the principles of the rating assessment system were revealed, a definition of the term "Rating" was given, its goals were indicated. As an example of the organization of the rating system of assessment, the Nyzhnii Novhorod State Pedagogical University and its "Regulations on the rating system for assessing the quality of student training" were used. It is noted that the rating includes: current check, midterm and final examinations. Further, all possible conditions under which the student receives points were identified and considered. On the example of the NSPU named after Kozma Minin transferring of the rating points into a five-point grading rating system is presented. Also, the types of violations for which points are discarded, are considered. As the study showed, comprehensive planned system yields productive results for students and the university.peer-reviewe

Повседневность в рассказах Бориса Екимова

Boris Ekimov’s stories of the 2000s which formed the collection “Saturday of Souls” are analyzed in the present article. The writer doesn’t set the purpose to recreate peasants’ Atlantis but perceives today of the village as a reality in which a person lives. The concepts of “daily life” and “daily occurrence” are differentiated in the article as the ones that have different extension and occur at different times. Daily life is classified as sacral, it is one of the manifestations of existence, while daily occurrence assumes an appeal to the private life of an ordinary person in the present and his/her inclusiveness into the civilized everyday life. The study of the everyday life of B. Ekimov’s characters that allowed him to describe the current state of the village, which is characterized by the daily life coordinates reduction, has become the purpose of this article. The deformed connections between people in the literary world of the writer are, first of all, demonstrated in the transformation of the image of the master and changes in the character of the neighborhood relationsВ настоящей статье анализируются рассказы Бориса Екимова 2000-х годов, составивших сборник «Родительская суббота». Писатель не ставит целью воссоздать крестьянскую Атлантиду, а воспринимает сегодняшний день деревни как данность, в которой живет человек. В статье разграничиваются понятия «быт» и «повседневность» как разнообъемные и разновременные. Быт отнесен к сакральному, это одно из проявлений бытия, повседневность же предполагает обращение к приватной жизни обычного человека в настоящем, его включенность в цивилизационный обиход. Целью статьи стало исследование повседневной жизни героев Б. Екимова, позволяющей ему описать современное состояние деревни, характеризующееся редуцированностью бытийных координат. В художественном мире писателя деформированные связи между людьми проявляются, в первую очередь, в трансформации образа хозяина и изменении характера соседских отношений

Batch pulping on the basis of natural substandard siliceous materials

It is shown that using silica sand of Tugansk deposit (Tomsk region) and marshalite of Elbash deposit (Novosibirsk region) having more developed specific surface in comparison with silica sand of Tashlin deposit (Ulyanovsk region) in combination with their grain defective structure provides an increase of batch chemical activity at the stage of silica- and glass-formation. The effective method of preparing glass batch using substandard fine-dispersed siliceous materials in glass production is their compaction