Square vortex solitons with a large angular momentum

We show the existence of square shaped optical vortices with a large value of the angular momentum hosted in finite size laser beams which propagate in nonlinear media with a cubic-quintic nonlinearity. The light profiles take the form of rings with sharp boundaries and variable sizes depending on the power carried. Our stability analysis shows that these light distributions remain stable when propagate, probably for unlimited values of the angular momentum, provided the hosting beam is wide enough. This happens if the peak amplitude approaches a critical value which only depends on the nonlinear refractive index of the material. A variational approach allows us to calculate the main parameters involved. Our results add extra support to the concept of surface tension of light beams that can be considered as a trace of the existence of a liquid of light.Comment: 6 pages, 6 figures, submitted to Phys. Rev.

Reconstruction of the historical and cultural landscape of the late XIX century"Settlement "Kamennaya melnitsa""in the process of future designers training

Today, the problem of preservation of historical and cultural landscapes as the objects of local history, eyewitnesses to the memory of Kazan development, as the objects for thedevelopment of domestic tourism in Tatarstan, is especially urgent. One of such objects is the lost cultural and historical landscape of the studied object “Settlement“ Kamennaya Melnitsa””, located at Vysokogorsk district of the Republic of Tatarstan. At the turn of the XVIII-XIX centuries, there was the flour production, belonging to the family of merchants - the Suslovs. In the course of the work, geological, hydrological, ecological and historical features of the Blue Lakes area and the history of flour milling industry, using water mills, were studied. The article presents the main provisions, which allow to implement the project of reconstruction the historical and cultural landscape of the “Settlement “Kamennaya Melnitsa””, located within the specially protected natural area of the "Blue Lakes" reserve, into the study programs of the additional education institutions of the small homeland history. This is done with the aim to preserve historical connection of generations, as well as to promote the process of reviviscence of cultural and historical objects. Detailed characteristics and description of the objects of historical and cultural landscape is given in the work. The practical experience is shown in a logical sequence from the initial studies of the surviving remnants of historical objects to the project of its renovation and 3-D visualization.Keywords: historical and cultural landscape, cultural and historical heritage, renovation, reconstruction, 3-D visualization

Laser in the axial electric field as a tool to search for P-, T- invariance violation

We consider rotation of polarization plane of the laser light when a gas laser is placed in a longitudinal electric field (10~kV/cm). It is shown that residual anisotropy of the laser cavity 10^{-6} and the sensitivity to the angle of polarization plane rotation about 10^{-11} -10^{-12} rad allows one to measure an electron EDM with the sensitivity about 10^{-30} e cm.Comment: 12 page

INNOVATIVE APPROACH IN PREPARING STUDENTS OF TECHNICAL UNIVERSITIES

В статье поднимается вопрос о специфики подхода к обучению в технических вузах с применением инновационных методик. Предложены инновационные решения, позволяющие улучшить качество образованияThe article raises the question of the specifics of the approach to training in technical universities. The proposed innovative solutions to improve the quality of educatio

Polarization-dependent transformation of a paraxial beam upon reflection and refraction: a real-space approach

We analyze the paraxial beam transformation upon reflection and refraction at a plane boundary. In contrast to the usual approach dealing with the beam angular spectrum, we apply the continuity conditions to explicit spatial representations of the electric and magnetic fields on both sides of the boundary. It is shown that the polarization-dependent distortions of the beam trajectory (in particular, the "longitudinal" Goos-H\"anchen shift and the "lateral" Imbert-Fedorov shift of the beam center of gravity) are directly connected to the incident beam longitudinal component and appear due to its transformation at the boundary.Comment: 10 pages, 1 figure. Formulae (32), (33), footnote 2 and Ref. 27 are added, some sentences are correcte

Lithologic-facies and paleogeographic features of Mid-Upper Jurassic oil-gas bearing sediments in Nurolsk depression (Western Siberia)

Bathonian-Callovian-Oxfordian sedimentation environment reconstruction in SE Nurolsk depression, Western Siberia has been described. Paleogeographic and litho-geochemical features of sediments, numerous plant remains and ichnofossils indicated the fact that this territory during the Naunaksk suite formation was the transition in-situ sedimentogenesis. Based on the integrated research data, the potential litho-facies were identified in the Mid-Upper sediments within Nurolsk depression, Western Siberia

Information and educational environment for realizing distance technologies

Distance technologies are widely used in educational process. The present work is devoted to the experience of implementation and usage of information and educational portal "Biotechnical Systems and Technologies". The portal integrates all participants interested in development of biomedical engineering education in Urals region. Portal has a modular design, that includes "Information", "Documents", "Education", "The Practice", "Enterprises" blocks, that allow one to realize various stages of educational processДистанционные технологии широко используются в образовательном процессе. Настоящая работа посвящена рассмотрению опыта внедрения и использования информационно-образовательного портала «Биотехнические системы и технологии». Портал объединяет всех участников, заинтересованных в развитии инженерного медико-биологического образования в Уральском регионе. Портал построен по модульному принципу, куда входят блоки «Информация», «Документы», «Учеба», «Практика», «Предприятия», с помощью которых можно реализовать различные этапы образовательного процесс

Excitonic effects on the two-color coherent control of interband transitions in bulk semiconductors

Quantum interference between one- and two-photon absorption pathways allows coherent control of interband transitions in unbiased bulk semiconductors; carrier population, carrier spin polarization, photocurrent injection, and spin current injection may all be controlled. We extend the theory of these processes to include the electron-hole interaction. Our focus is on photon energies that excite carriers above the band edge, but close enough to it so that transition amplitudes based on low order expansions in $\mathbf{k}$ are applicable; both allowed-allowed and allowed-forbidden two-photon transition amplitudes are included. Analytic solutions are obtained using the effective mass theory of Wannier excitons; degenerate bands are accounted for, but envelope-hole coupling is neglected. We find a Coulomb enhancement of two-color coherent control process, and relate it to the Coulomb enhancements of one- and two-photon absorption. In addition, we find a frequency dependent phase shift in the dependence of photocurrent and spin current on the optical phases. The phase shift decreases monotonically from $\pi /2$ at the band edge to 0 over an energy range governed by the exciton binding energy. It is the difference between the partial wave phase shifts of the electron-hole envelope function reached by one- and two-photon pathways.Comment: 31 pages, 4 figures, to be published in Phys. Rev.

Транспорт катионов в эритроцитах при бронхиальной астме

The content and ion-transporting systems of monovalent ions and calcium in patients with bronchial asthma were studied through an example of erythrocyte membrane. An increase of intracellular concentration of sodium associated with increased cellular influx of this ion (Na+, K+, 2Clco-transport) and decreased efflux (Na+, K+-AT Pase) has been revealed. Decreased activity of Ca2+-ATPase — an enzyme sustaining physiological levels of intracellular calcium has been observed. Possible mechanisms of involvement of the above-mentioned abnormalities in bronchial asthma pathogenesis have been suggested.

Instrumental program complex on biotechnical systems

The instrumental and program system, which is a computer system of acquisition and control of data from biomedical devices, is described. The system is designed for laboratory and practical training on the disciplines of professional cycle in the framework of educational program "Biotechnical Systems and Technologies"Приведено описание инструментально-программного комплекса, который представляет собой компьютерную систему сбора и управления данными приборов медико-биологического назначения. Комплекс предназначен для проведения лабораторных и практических занятий в рамках дисциплин профессионального цикла направления подготовки «Биотехнические системы и технологии