Observation of asymmetric spectrum broadening induced by silver nanoparticles in a heavy-metal oxide glass

We demonstrate experimentally and support by a theoretical analysis an effect of asymmetric spectrum broadening, which results from doping of silver nanoparticles into a heavy-glass matrix, 90(0.5WO3-0.3SbPO4-0.2PbO)-10AgCl. The strong dispersion of the effective nonlinear coefficient of the composite significantly influences the spectral broadening via the self-phase modulation, and leads to a blue upshift of the spectrum. Further extension of the spectrum towards shorter wavelengths is suppressed by a growing loss caused by the plasmon resonance in the silver particles. The red-edge spectral broadening is dominated by the stimulated Raman Scattering.Comment: Accepted for publishing epl13477; EPL Journal 201

Карнавализация Бродвея Верой Зубаревой. К вопросу о феномене пограничности в рецепции современного поэта-эмигранта

In this article research strategies are determined by attention to the phenomenon of the modern Russian emigrant poet and explication in the work of the borderline factor. A model has been proposed for studying borderness through carnivalization indicators when studying the works of modern Russian emigrant poets. As an example of the implementation of such a model was chosen the Broadway’s poem by Vera Zubareva. The indicators are considered of the rootedness of poetic consciousness by V. Zubareva into the native culture and allusions of Russian literature shown in the analyzed poem. Carnavalization is an indicator of the borderness of Broadway topos and emigrant author's consciousness in the artistic interpretation by V. Zubareva. It is meaningful to include in the lyrical plot along with the realities of New York and their carnivalization of significant reminiscence from Russian classics. In the panorama of modern Broadway created the study revealed the acceptance by V. Zubareva of the creative heritage of Gogol, Dostoevsky, Bulgakov.In this article research strategies are determined by attention to the phenomenon of the modern Russian emigrant poet and explication in the work of the borderline factor. A model has been proposed for studying borderness through carnivalization indicators when studying the works of modern Russian emigrant poets. As an example of the implementation of such a model was chosen the Broadway’s poem by Vera Zubareva. The indicators are considered of the rootedness of poetic consciousness by V. Zubareva into the native culture and allusions of Russian literature shown in the analyzed poem. Carnavalization is an indicator of the borderness of Broadway topos and emigrant author's consciousness in the artistic interpretation by V. Zubareva. It is meaningful to include in the lyrical plot along with the realities of New York and their carnivalization of significant reminiscence from Russian classics. In the panorama of modern Broadway created the study revealed the acceptance by V. Zubareva of the creative heritage of Gogol, Dostoevsky, Bulgakov.В данной статье исследовательские стратегии определены вниманием к феномену современного русского поэта-эмигранта и соответственно экспликации в творчестве фактора пограничности. Предложена модель изучения пограничности через показатели карнавализации при филологическом анализе произведений современных русских поэтов-эмигрантов. В качестве примера реализации такой модели избрано бродвейское стихотворение Веры Зубаревой. Рассмотрены показатели укорененности поэтического сознания В. Зубаревой в родную культуру, а также аллюзии русской литературы, проявленные в анализируемом стихотворении. В художественной интерпретации В. Зубаревой карнавализация является показателем пограничности бродвейского топоса и авторского эмигрантского сознания. Осмыслено включение в лирический сюжет В. Зубаревой наравне с реалиями Нью-Йорка и их карнавализацией значимых реминисценций из русской классики. В создаваемой панораме современного Бродвея в ходе исследования выявлена преемственная связь В. Зубаревой с творческим наследием Гоголя, Достоевского, Булгакова. &nbsp

Study of Posting Activities of Russian Users on Social Media

Content marketing on social media depends on trends in consumer behaviors. A changing focus and emphasis on audience activities on social media are a key optimization problem in social media marketing (SMM). A solution to this problem lies in a field of ongoing empirical studies of posting frequency. In the review of the literature, authors highlight the role of social media as a promising channel for a direct interaction of companies/brands with consumers. Based on theoretical generalizations, authors present a generation sequence of an SMM content strategy. The article also includes an analysis of posting activities of users from Russia on well-known social media. A cost-benefit analysis of posting activities rests upon some factors: socio-demographic characteristics of users, a content format, time and day of the week parameters, etc. Data come from such sources as aggregated statistics of social media and selective interviewing. An analysis of activities for users from Russia has shown that VKontakte is the most popular platform; Instagram is the second, while Facebook is the third. Odnoklassniki and Twitter are less preferred. VKontakte users respond best to short posts. On Facebook, entries with medium-sized texts have got the highest number of responds. On Instagram, long posts work better. The photo format is a leader in all of the social media. The video format has a middle position, while a text is the most inefficient type of content. There is strong differentiation in response time depending on a target audience. Findings have made it possible to present recommendations for optimization of content marketing

Optical control of electron spin coherence in CdTe/(Cd,Mg)Te quantum wells

Optical control of the spin coherence of quantum well electrons by short laser pulses with circular or linear polarization is studied experimentally and theoretically. For that purpose the coherent electron spin dynamics in a n-doped CdTe/(Cd,Mg)Te quantum well structure was measured by time-resolved pump-probe Kerr rotation, using resonant excitation of the negatively charged exciton (trion) state. The amplitude and phase shifts of the electron spin beat signal in an external magnetic field, that are induced by laser control pulses, depend on the pump-control delay and polarization of the control relative to the pump pulse. Additive and non-additive contributions to pump-induced signal due to the control are isolated experimentally. These contributions can be well described in the framework of a two-level model for the optical excitation of the resident electron to the trion.Comment: 15 pages, 18 figure

Spin dynamics of electrons and holes in InGaAs/GaAs quantum wells at milliKelvin temperatures

The carrier spin dynamics in a n-doped (In,Ga)As/GaAs quantum well has been studied by time-resolved Faraday rotation and ellipticity techniques in the temperature range down to 430 milliKelvin. These techniques give data with very different spectral dependencies, from which nonetheless consistent information on the spin dynamics can be obtained, in agreement with theoretical predictions. The mechanisms of long-lived spin coherence generation are discussed for the cases of trion and exciton resonant excitation. We demonstrate that carrier localization leads to a saturation of spin relaxation times at 45 ns for electrons below 4.5 K and at 2 ns for holes below 2.3 K. The underlying spin relaxation mechanisms are discussed.Comment: 8 pages, 8 figure

Coherent spin relaxation in molecular magnets

Numerical modelling of coherent spin relaxation in nanomagnets, formed by magnetic molecules of high spins, is accomplished. Such a coherent spin dynamics can be realized in the presence of a resonant electric circuit coupled to the magnet. Computer simulations for a system of a large number of interacting spins is an efficient tool for studying the microscopic properties of such systems. Coherent spin relaxation is an ultrafast process, with the relaxation time that can be an order shorter than the transverse spin dephasing time. The influence of different system parameters on the relaxation process is analysed. The role of the sample geometry on the spin relaxation is investigated.Comment: Latex file, 22 pages, 7 figure

Categoricity Spectra for Rigid Structures

© 2016 by University of Notre Dame. For a computable structure M, the categoricity spectrum is the set of all Turing degrees capable of computing isomorphisms among arbitrary computable copies of M. If the spectrum has a least degree, this degree is called the degree of categoricity of M. In this paper we investigate spectra of categoricity for computable rigid structures. In particular, we give examples of rigid structures without degrees of categoricity

Soil microorganisms in the urban ecosystems of the russian subarctic (Murmansk region, Apatity)

A comprehensive study of the quantitative and qualitative parameters of soil microfungi, bacteria and algae communities in the Apatity city, located in the subarctic zone of Russia, was carried out for the first time. Urban soil samples were taken from various landuse zones (residential, recreational) and compared to arable and forest soils. In the residential zone, a decrease in the number of microfungi in the topsoil horizon to 1.1 thous. CFU/g compared to 22.7 thous. CFU/g in forest soil was revealed. In the residential zone, an increase was found in the number of saprotrophic bacteria to 7.8 million cells g-1 and oligotrophic to 10.9 million cells g-1 compared to 2.6 million cells g-1 and 1.8 million cells g-1 respectively in forest soils. In the recreational zone, the number of soil microorganisms was similar to that in the forest. A decrease in the species diversity of microfungi in the soil of the residential zone and an increase in the diversity of soil algae were revealed. Among the dominant species of fungi in urban soils, atypical species, including pathogenic ones for humans (Penicillium dierckxii, Stachybotris echinatus, Fusarium sp.), were found. In the algal community, diatoms, yellow-green algae, and cyanobacteria appeared in urban soils in comparison with forest soil. As a result of changes in the quantitative and qualitative indicators of soil microbial communities, a decrease in the enzymatic activity of soils has been noted. This may indicate a weakening of the ecosystem functions of urban soils and an increase in the degree of toxicity for living organisms and humans