Polish Question in the Discourse of Russian Pre-Revolutionary Social Thought

An attempt is made to reveal the key elements of the discourse of ethnic diversity management in Russian pre-revolutionary social thought. Numerous texts published by representatives of various sociopolitical views (Westerners, Slavophiles, liberals, conservatives, populists and socialists) devoted to the description and assessment of the policy of the Russian government in relation to national regions in the period under review are analyzed. The study was conducted on the basis of the analysis of mainly English-language scientific literature. Poland was chosen as a model region, that is, the main attention in the article is focused on the Polish question. The choice of this national outskirts is due to the following: on the one hand, it compelled the most close attention of representatives of the Russian pre-revolutionary social movement, and on the other, this territory was the place of testing of various incorporation practices by the Russian government. The study showed that, despite different political views and ideological platforms, Russian intellectuals clearly defined the intentions of the authorities, which consisted in the gradual integration of the periphery into the common imperial space, first on the administrative-legal, and then the cultural field. It is shown that the undulating nature of this process was absolutely opportunistic

Thermal switch of oscillation frequency in belousov- zhabotinsky liquid marbles

© 2019 The Authors. External control of oscillation dynamics in the Belousov- Zhabotinsky (BZ) reaction is important for many applications including encoding computing schemes. When considering the BZ reaction, there are limited studies dealing with thermal cycling, particularly cooling, for external control. Recently, liquid marbles (LMs) have been demonstrated as a means of confining the BZ reaction in a system containing a solid-liquid interface. BZ LMs were prepared by rolling 50 ml droplets in polyethylene (PE) powder. Oscillations of electrical potential differences within the marble were recorded by inserting a pair of electrodes through the LM powder coating into the BZ solution core. Electrical potential differences of up to 100mV were observed with an average period of oscillation ca 44 s. BZ LMs were subsequently frozen to 218C to observe changes in the frequency of electrical potential oscillations. The frequency of oscillations reduced upon freezing to 11mHz cf. 23 mHz at ambient temperature. The oscillation frequency of the frozen BZ LM returned to 23 mHz upon warming to ambient temperature. Several cycles of frequency fluctuations were able to be achieved

Fractional dynamics of coupled oscillators with long-range interaction

We consider one-dimensional chain of coupled linear and nonlinear oscillators with long-range power-wise interaction. The corresponding term in dynamical equations is proportional to $1/|n-m|^{\alpha+1}$. It is shown that the equation of motion in the infrared limit can be transformed into the medium equation with the Riesz fractional derivative of order $\alpha$, when $0<\alpha<2$. We consider few models of coupled oscillators and show how their synchronization can appear as a result of bifurcation, and how the corresponding solutions depend on $\alpha$. The presence of fractional derivative leads also to the occurrence of localized structures. Particular solutions for fractional time-dependent complex Ginzburg-Landau (or nonlinear Schrodinger) equation are derived. These solutions are interpreted as synchronized states and localized structures of the oscillatory medium.Comment: 34 pages, 18 figure

Двухконверторный силовой активный фильтр с пониженными динамическими потерями: синтез управления и моделирование

Nowadays, active power filters represent one of the most efficient means to reduce inactive power components which provides proper quality of electricity at common network connectivity points. Dynamic power losses in the valves that have a significant impact on the efficiency of the converter and, accordingly, determine the feasibility of using these filters in each specific situation, are among their key parameters. Along with the solution of the problem of ensuring the proper quality of electricity at common network connectivity points, the task of reducing dynamic losses in the valves becomes especially relevant. The purpose of the study is to increase the efficiency of active filtration in terms of reducing dynamic losses in the valves while ensuring high-quality voltages at common network connectivity points and currents consumed from the network. To achieve the goal, it is proposed to jointly use a dual-converter active power filter operating in a mode with different conversion frequencies and rated converter capacities, and an interface LCL-filter. Synthesis of converter control is performed. As a control method, the sliding mode control has been used. The efficiency of the proposed system was assessed by modeling in the MATLAB-Simulink application software package. The simulation results confirm the possibility of organizing a mode of operation in which the conversion frequencies and rated capacities of the converters of active power filters are different. In such a case, the currents and voltages consumed from the network at common network connectivity points have an almost perfect harmonic shape; and the phase shift of the network currents relative to the corresponding voltages has a negligible value. It is shown that the organization of the operating mode of converters with different conversion frequencies and rated capacities can significantly reduce the dynamic losses in the switches of active power filters.Cиловые активные фильтры – одно из наиболее эффективных средств снижения неактивных составляющих потребляемой из сети мощности, позволяющих обеспечить надлежащее качество электроэнергии в точках общего подключения к сети. К ключевым параметрам фильтров относятся динамические потери мощности в вентилях, которые оказывают влияние на КПД преобразователя и соответственно определяют целесообразность применения указанных фильтров в каждой конкретной ситуации. Наряду с решением задачи обеспечения надлежащего качества электроэнергии в точках общего подключения к сети особую актуальность приобретает снижение динамических потерь в вентилях. Цель исследования – повышение эффективности активной фильтрации в части снижения динамических потерь в вентилях при обеспечении высокого качества напряжений в точках общего подключения к сети и потребляемых из сети токов. Для ее достижения предложено совместно использовать двухконверторный силовой активный фильтр, работающий в режиме с различными частотами преобразования и установленными мощностями конверторов, и интерфейсный LCL-фильтр. Выполнен синтез управления преобразователем. В качестве метода используется управление на скользящих режимах. Эффективность предложенной системы оценена посредством моделирования в пакете прикладных программ MATLAB-Simulink. Результаты имитационного моделирования подтверждают возможность организации режима работы, при котором частоты преобразования и установленные мощности конверторов силовых активных фильтров различны. При этом потребляемые из сети токи и напряжения в точках общего подключения к сети имеют практически идеальную гармоническую форму. Фазовый сдвиг сетевых токов относительно соответствующих напряжений пренебрежимо мал. Показано, что организация режима работы конверторов с различными частотами преобразования и установленными мощностями позволяет существенно снизить динамические потери в ключах силовых активных фильтров

Correlation functions near Modulated and Rough Surfaces

In a system with long-ranged correlations, the behavior of correlation functions is sensitive to the presence of a boundary. We show that surface deformations strongly modify this behavior as compared to a flat surface. The modified near surface correlations can be measured by scattering probes. To determine these correlations, we develop a perturbative calculation in the deformations in height from a flat surface. Detailed results are given for a regularly patterned surface, as well as for a self-affinely rough surface with roughness exponent $\zeta$. By combining this perturbative calculation in height deformations with the field-theoretic renormalization group approach, we also estimate the values of critical exponents governing the behavior of the decay of correlation functions near a self-affinely rough surface. We find that for the interacting theory, a large enough $\zeta$ can lead to novel surface critical behavior. We also provide scaling relations between roughness induced critical exponents for thermodynamic surface quantities.Comment: 31 pages, 2 figure

Muon-Spin Rotation Spectra in the Mixed Phase of High-T_c Superconductors : Thermal Fluctuations and Disorder Effects

We study muon-spin rotation (muSR) spectra in the mixed phase of highly anisotropic layered superconductors, specifically Bi_2+xSr_2-xCaCu_2O_8+delta (BSCCO), by modeling the fluid and solid phases of pancake vortices using liquid-state and density functional methods. The role of thermal fluctuations in causing motional narrowing of muSR lineshapes is quantified in terms of a first-principles theory of the flux-lattice melting transition. The effects of random point pinning are investigated using a replica treatment of liquid state correlations and a replicated density functional theory. Our results indicate that motional narrowing in the pure system, although substantial, cannot account for the remarkably small linewidths obtained experimentally at relatively high fields and low temperatures. We find that satisfactory agreement with the muSR data for BSCCO in this regime can be obtained through the ansatz that this ``phase'' is characterized by frozen short-range positional correlations reflecting the structure of the liquid just above the melting transition. This proposal is consistent with recent suggestions of a ``pinned liquid'' or ``glassy'' state of pancake vortices in the presence of pinning disorder. Our results for the high-temperature liquid phase indicate that measurable linewidths may be obtained in this phase as a consequence of density inhomogeneities induced by the pinning disorder. The results presented here comprise a unified, first-principles theoretical treatment of muSR spectra in highly anisotropic layered superconductors in terms of a controlled set of approximations.Comment: 50 pages Latex file, including 10 postscript figure

Tight-binding approach to excitons bound to monolayer impurity planes: strong radiative properties of InAs in GaAs

A theory of Wannier-Mott excitons bound to monolayer (ML) impurity planes in semiconductors, which is based on Green's function tight-binding calculations of the single-particle states, is presented. Binding energies and oscillator strengths for one and two MLs of InAs in GaAs are predicted to be much larger than in the usual InxGa1-xAs/GaAs thick quantum wells. The reason is the increase of effective mass of both carriers due to folding of the InAs bands along the growth direction. The results suggest that ML insertions can be used as intense light sources in light-emitting devices

Public political narratives: developing a neglected source through the exploratory case of Russia in the Putin-Medvedev era

The place of narrative in political science is an issue that resurfaces with regularity, usually focusing on the questions of generalisability, evidence and causality which lie at the heart of the discipline. Most such debate concerns the use of narrative by political scientists. Far less attention has been devoted to the use of narrative by political actors, despite its relative ubiquity. Even where such attention has been given, it concentrates less on the narrative per se, and more on its performance and impact. However, the nature of public political narratives means that analysis of them facilitates a holistic understanding of their narrators' politics. A public political narrative consists of a sequential account given by political actors connecting selected, specific developments so as to impose a desired order on them. Taking contemporary Russia as an exploratory case, narrative analysis draws out the motivations, world view and inconsistencies within the Putin-Medvedev regime. Recurring motifs and symbols identify the regime's political priorities, explaining policy choices and revealing future concerns. Narrative has a predictive aspect, identifying likely policy responses to unexpected events. Narratives capture time, and shifts in their temporalities indicate changes in self-conceptualisation and political priorities. Temporal appropriations include or exclude particular agential and causal explanations. The relationship between their plots and subplots represents a political signalling process. Public political narratives provide temporally and spatially specific exceptionalist accounts, but their combinatory quality also facilitates comparative analysis. The approach essayed here provides methodological generalisability, arguing that the neglect of public political narratives merits correcting

Strong interface-induced spin-orbit coupling in graphene on WS2

Interfacial interactions allow the electronic properties of graphene to be modified, as recently demonstrated by the appearance of satellite Dirac cones in the band structure of graphene on hexagonal boron nitride (hBN) substrates. Ongoing research strives to explore interfacial interactions in a broader class of materials in order to engineer targeted electronic properties. Here we show that at an interface with a tungsten disulfide (WS2) substrate, the strength of the spin-orbit interaction (SOI) in graphene is very strongly enhanced. The induced SOI leads to a pronounced low-temperature weak anti-localization (WAL) effect, from which we determine the spin-relaxation time. We find that spin-relaxation time in graphene is two-to-three orders of magnitude smaller on WS2 than on SiO2 or hBN, and that it is comparable to the intervalley scattering time. To interpret our findings we have performed first-principle electronic structure calculations, which both confirm that carriers in graphene-on-WS2 experience a strong SOI and allow us to extract a spin-dependent low-energy effective Hamiltonian. Our analysis further shows that the use of WS2 substrates opens a possible new route to access topological states of matter in graphene-based systems.Comment: Originally submitted version in compliance with editorial guidelines. Final version with expanded discussion of the relation between theory and experiments to be published in Nature Communication