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We investigate a nonlinear response of the physical vacuum by the example of the third harmonic in radiation of the electron-positron-photon plasma excited by a strong time dependent electric field at the focus spot of counterpropagating laser pulses. The investigation was developed within the framework of the Bogoliubov-Born-Green-Kirkwood-Yvon kinetic theory nonperturbatively describing vacuum creation of the quasiparticle electron-positron plasma (EPP) and different channels of its interaction with the photon subsystem in the single-photon approximation that are opened in the presence of a strong semiclassical field. We investigate the radiation of EPP in the annihilation channel on the basis of the well known approximations and compare the obtained result with the semiclassical radiation of the plasma oscillations. In the high-frequency range for large adiabaticity parameter the quantum radiation dominates in comparison with the semiclassical one.

The vast increase in the number of forced migrants during the European migration crisis has compelled the receiving countries to concentrate on the issues of migrant reception and accommodation. This study aims to demonstrate how the patterns of settlement of Syrian and Iraqi migrants changed in 2014-2019. We propose a new methodology, building on the Her­findahl-Hirschman index, an indicator of the level and direction of the spatial concentration - deconcentration of migrants, and the Ryabtsev index, which is used to measure the proximity between the settlement structures of migrants and the Swedes. It is established there was a deconcentration of migrants during the crisis (espe­cially in its ascendant phase), carried out by the Swedish authorities. However a reverse process took place in the descendant phase, as a result of self-arranged migrants’ resettlement. The deconcentration of Iraqis and Syrians led to the convergence between the settlement structure typical of immigrants and the Swedes, whilst concentration resulted in divergence accompanied by the emergence of close-knit immi­grant communities on the outskirts of Sweden’s largest cities. The formation of such communi­ties, seen as vulnerable by the national authorities and marked by a high crime rate, impedes the integration of Syrian and Iraqi immigrants into Swedish society.

It has been shown that during the outburst of accretion activity observed in UX Ori type star RZ Psc in 2013, the accretion rate increased approximately by an order of magnitude. This means that the accretion process at the late stages of the Pre-Main Sequence evolution is very unstable. Using the spectra obtained during this episode we have studied the magnetospheric emission in the H$\alpha$ line. Models of magnetospheric accretion are calculated to obtain the parameters of the magnetosphere from this observation. In present work we have taken into account the influence of the recombination delay effect during gas motion in the stellar magnetosphere. The accounting for this effect and the presence of the magnetospheric absorption in the IR CaII triplet lines and its absence in D Na I resonance lines allowed us to place a lower limit on the temperature in the magnetosphere at $\approx$ 10000 K, which significantly improved precision of our estimate of accretion rate. According to the best fit model the logarithm of accretion rate is $\log\dot{M} = -10.1\pm0.3$ ($\dot{M} \approx 7\times10^{-11}$ M$_\odot$yr$^{-1}$) and the inclination angle of RZ Psc is $43\pm 3^\circ$. It is less than the inclination, typical for the UX Ori stars (about 70$^\circ$), that explains the weak photometric variability of this star. Using the obtained accretion rate and magnetosphere radius we estimate the strength of the dipole component of the magnetic field of RZ Psc $\approx$ 0.1 kGs., Comment: This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society Published by Oxford University Press on behalf of the Royal Astronomical Society

We train a deep learning artificial neural network model, Spatial Attention U-Net to recover useful ionospheric signals from noisy ionogram data measured by Hualien's Vertical Incidence Pulsed Ionospheric Radar. Our results show that the model can well identify F2 layer ordinary and extraordinary modes (F2o, F2x) and the combined signals of the E layer (ordinary and extraordinary modes and sporadic Es). The model is also capable of identifying some signals that were not labeled. The performance of the model can be significantly degraded by insufficient number of samples in the data set. From the recovered signals, we determine the critical frequencies of F2o and F2x and the intersection frequency between the two signals. The difference between the two critical frequencies is peaking at 0.63 MHz, with the uncertainty being 0.18 MHz., Comment: 17 pages, 7 figures, 3 tables

The Nuclotron-base Ion Collider fAcility (NICA) is under construction at the Joint Institute for Nuclear Research (JINR), with commissioning of the facility expected in late 2022. The Multi-Purpose Detector (MPD) has been designed to operate at NICA and its components are currently in production. The detector is expected to be ready for data taking with the first beams from NICA. This document provides an overview of the landscape of the investigation of the QCD phase diagram in the region of maximum baryonic density, where NICA and MPD will be able to provide significant and unique input. It also provides a detailed description of the MPD set-up, including its various subsystems as well as its support and computing infrastructures. Selected performance studies for particular physics measurements at MPD are presented and discussed in the context of existing data and theoretical expectations., Comment: 53 pages, 68 figures, submitted as a Review article to EPJA

В данной исследовательской статье рассматривается вопрос формирования цифровых навыков в процессе обучения у студентов, осваивающих в вузах различные направления подготовки. Обсуждается ситуация с наличием специфических, актуальных для конкретных направлений подготовки, и сквозных, общих, цифровых навыков, формируемых за пределами связанных с ИТ-индустрией направлений подготовки. Высказано предположение, что во всех направлениях подготовки заложена «подушка» общих цифровых навыков, которая может быть закреплена как де-юре – в методической и нормативной базе образовательного процесса, так и де-факто – в практиках обучения. Входе исследования определена рамка общих и специфических цифровых навыков. Для проверки гипотез анализируются две группыданных: нормативная иметодическая базыобразовательных программ (развитие де-юре) и результатыанкетирования студентов, позволяющего определить, как интегрированы практики развития и использования цифровых навыков в их учебе (развитие де-факто). Исследование проводилось по семи направлениям подготовки с заведомо широким диапазоном – от медицины до информационных технологий и филологии. Показано, что цифровые навыки де-юре отражены во всех направлениях подготовки, но нормативное закрепление преимущественно имеют общие, а не специфические цифровые навыки. Установлено наличие разрыва между де-юре и де-факто развитием цифровых навыков, данный разрыв варьируется на различных направлениях подготовки. Результаты исследования могут быть полезны в разработке стратегий развития цифровых навыков в вузах, а также при корректировке методической базы образовательных программ в части развития цифровых навыков., The article discusses the problem of within-the-education-process fostering digital skills among university students of various training programs. The specific skills (relevant to a particular sphere) are differentiated from the general ones (digital skills formed beyond the IT industry). The authors suggest that all training programs contain a «pillow» of general digital skills, which can be fixed both de jure – in the methodological and regulatory bases of the educational process, and de facto – in teaching practices. The study identifies a framework for general and specific digital skills. To test the hypotheses, two groups of data are analyzed: the normative and methodological bases of educational programs (fostering skills de jure) and students’ questionnaire answers on how the practices of developing and using digital skills in their studies are integrated (fostering skills de facto). The research is carried out in seven programs with obviously wide differences – from medicine to information technology and philology. The research has shown that digital skills are de jure represented in all programs, but normative consolidation is more typical for general skills, not for specific digital ones. There is identified a gap between de jure and de facto fostering digital skills, and this gap is various for different programs. The research results can be used in universities when designing strategies to form digital skills or when modifying such skills-related methodological bases of training programs.

The allotropes of a new layered material, phosphorus carbide (PC), have been predicted recently, and a few of these predicted structures have already been successfully fabricated. Herein, by using first-principles calculations, we investigate the effects of rippling an α-PC monolayer, one of the most stable modifications of layered PC, under large compressive strains. Similar to phosphorene, layered PC is found to have the extraordinary ability to bend and form ripples with large curvatures under a sufficiently large strain applied along its armchair direction. The band gap, work function, and Young’s modulus of a rippled α-PC monolayer are predicted to be highly tunable by strain engineering. Moreover, a direct-indirect band gap transition is observed under compressive strains in the range from 6% to 11%. Another important feature of the α-PC monolayer rippled along the armchair direction is the possibility of its rolling to a PC nanotube (PCNT) under an extreme compressive strain. These tubes of different sizes exhibit high thermal stability, possess a comparably high Young’s modulus, and a well tunable band gap which can vary from 0 to 0.95 eV. In addition, for both structures, rippled α-PC and PCNTs, the changes of their properties under compressive strain are explained in terms of the modification of their structural parameters.

It was previously demonstrated, that thermal decarbonylation of N-substituted 2,3-dihydro-2,3-pyrroldiones afforded imidoylketenes, whose chemical behavior largely depends on the nature of substituents at N-1. It was discovered that N-(diphenylenamino)pyrrolediones experienced facile CO-extrusion at elevated temperatures and the resulting a zwitterionic dihydropyrazolone species, which can be represented by enolate-iminium 1,4-dipole resonance form. In the absence of dipolarophiles, the products of [4+4]-cyclodimerization – bis(pyrazolo)dioxadiazocines – were formed in high yields. To this end, we generated the ketenes in the presence of alkyl vinyl ethers, aldehydes, ketenes, nitriles and isocyanides targeting products of dipolar cycloadditions. We further elaborated on the development of various synthetic schemes involving cycloaddition of these unusual 1,4-dipoles. Dipyrazolodioxadiazocines are shelf-stable "ready-to-use" precursors for an in situ generation of enolate-iminium 1,4-dipoles.

Various “wet” synthetic chemical techniques are widely used for the production of multifunctional inorganic materials. In contrast to the standard high-temperature solid state route, methods based on the dissolution of starting reagents allow one to obtain phases with given particle morphology and particle size distribution. Besides, with this approach, the defect structure can be efficiently controlled by varying the synthesis conditions and solution preparation. These advantages are important for producing luminescent materials.

Magnetic properties of porous spheres BiFeO3 have been studied at temperatures ranging from 2 to 300 K. A transition to cluster spin glass state has been detected in the region of about 100 K. The presence of the transition is confirmed by nonlinear variation of coercive force and the appearance of exchange displacement of magnetic hysteresis loops at temperature below 100 K. Temperature dependence of magnetization for zero-field cooled regime exhibit a maximum at some temperature Tm. The function Tm(H) (H is magneic field) changes in accordance with Almeida-Thouless line. The performed measurements of the frequency dependence of AC susceptibility confirm the behavior of spin glass with spin freezing temperature Tf = 116 K. The critical index zν = 2.5 agrees well with the mean-field theory zν = 2.0. © 2020, ITMO University. All rights reserved.

We present a detailed analysis of the self-consistent system of kinetic equations (KEs) describing electron-positron pair production from vacuum under the action of a spatially homogeneous time-dependent electric field of arbitrary polarization. The physical significance of all the basic functions of the kinetic theory is ascertained. It is demonstrated that the total system of the KEs consists of two coupled quasiparticle and spin subsystems with their integrals of motion. A projection method is proposed in order to obtain the KE system in two particular cases: linearly polarized external electric field and (2+1)-dimensional description of quasiparticles in graphene. We also address the energy conservation law taking into account the internal plasma field and describe an alternative rigorous derivation of the KE system., Comment: 15 pages

For pure metals aluminum and magnesium and for chemical compounds Al₃Mg, Al₂Mg, AlMg and AlMg₃ with crystallographic orientations (100), (110) and (111) the work function is calculated from the first principles in the framework of the density functional theory. It is shown that the dependence of the work function on the magnesium concentration in aluminium is nonlinear. The reasons for the work function differences of chemical compounds depending on the crystallographic orientation are analysed.

Sensing with optical whispering gallery modes (WGMs) is a rapidly developing detection method in modern microfluidics research. This method explores the perturbations of spectra of WGMs propagating along the wall of an optical microcapillary to characterize the liquid medium inside it. Here we show that WGMs in a silica microcapillary can be fully localized (rather than perturbed) by evanescent coupling to a water droplet and, thus, form a high-quality-factor microresonator. The spectra of this resonator, measured with a microfiber translated along the capillary, present a hierarchy of resonances that allow us to determine the size of the droplet and variation of its length due to the evaporation. The resolution of our measurements of this variation equal to 4.5 nm is only limited by the resolution of the optical spectrum analyzer used. The discovered phenomenon of complete localization of light in liquid-filled optical microcapillaries suggests a new type of microfluidic photonic device as well as an ultraprecise method for microfluidic characterization.

Sensing with optical whispering gallery modes (WGMs) is a rapidly developing detection method in modern microfluidics research. This method explores the perturbations of spectra of WGMs propagating along the wall of an optical microcapillary to characterize the liquid medium inside it. Here we show that WGMs in a silica microcapillary can be fully localized (rather than perturbed) by evanescent coupling to a water droplet and, thus, form a high-quality-factor microresonator. The spectra of this resonator, measured with a microfiber translated along the capillary, present a hierarchy of resonances that allow us to determine the size of the droplet and variation of its length due to the evaporation. The resolution of our measurements of this variation equal to 4.5 nm is only limited by the resolution of the optical spectrum analyzer used. The discovered phenomenon of complete localization of light in liquid-filled optical microcapillaries suggests a new type of microfluidic photonic device as well as an ultraprecise method for microfluidic characterization.

Symmetries of the physical world have guided formulation of fundamental laws, including relativistic quantum field theory and understanding of possible states of matter. Topological defects (TDs) often control the universal behavior of macroscopic quantum systems, while topology and broken symmetries determine allowed TDs. Taking advantage of the symmetry-breaking patterns in the phase diagram of nanoconfined superfluid $^3$He, we show that half-quantum vortices (HQVs) -- linear topological defects carrying half quantum of circulation -- survive transitions from the polar phase to other superfluid phases with polar distortion. In the polar-distorted A phase, HQV cores in 2D systems should harbor non-Abelian Majorana modes. In the polar-distorted B phase, HQVs form composite defects -- walls bounded by strings hypothesized decades ago in cosmology. Our experiments establish the superfluid phases of $^3$He in nanostructured confinement as a promising topological media for further investigations ranging from topological quantum computing to cosmology and grand unification scenarios., Comment: 17 pages, 11 figures

Sensing with optical whispering gallery modes (WGMs) is a rapidly developing detection method in modern microfluidics research. This method explores the perturbations of spectra of WGMs propagating along the wall of an optical microcapillary to characterize the liquid medium inside it. Here we show that WGMs in a silica microcapillary can be fully localized (rather than perturbed) by evanescent coupling to a water droplet and, thus, form a high-quality-factor microresonator. The spectra of this resonator, measured with a microfiber translated along the capillary, present a hierarchy of resonances that allow us to determine the size of the droplet and variation of its length due to the evaporation. The resolution of our measurements of this variation equal to 4.5 nm is only limited by the resolution of the optical spectrum analyzer used. The discovered phenomenon of complete localization of light in liquid-filled optical microcapillaries suggests a new type of microfluidic photonic device as well as an ultraprecise method for microfluidic characterization.

Sensing with optical whispering gallery modes (WGMs) is a rapidly developing detection method in modern microfluidics research. This method explores the perturbations of spectra of WGMs propagating along the wall of an optical microcapillary to characterize the liquid medium inside it. Here we show that WGMs in a silica microcapillary can be fully localized (rather than perturbed) by evanescent coupling to a water droplet and, thus, form a high-quality-factor microresonator. The spectra of this resonator, measured with a microfiber translated along the capillary, present a hierarchy of resonances that allow us to determine the size of the droplet and variation of its length due to the evaporation. The resolution of our measurements of this variation equal to 4.5 nm is only limited by the resolution of the optical spectrum analyzer used. The discovered phenomenon of complete localization of light in liquid-filled optical microcapillaries suggests a new type of microfluidic photonic device as well as an ultraprecise method for microfluidic characterization.

We study simultaneous collisions of two, three, and four kinks and antikinks of the $\phi^6$ model at the same spatial point. Unlike the $\phi^4$ kinks, the $\phi^6$ kinks are asymmetric and this enriches the variety of the collision scenarios. In our numerical simulations we observe both reflection and bound state formation depending on the number of kinks and on their spatial ordering in the initial configuration. We also analyze the extreme values of the energy densities and the field gradient observed during the collisions. Our results suggest that very high energy densities can be produced in multi-kink collisions in a controllable manner. Appearance of high energy density spots in multi-kink collisions can be important in various physical applications of the Klein-Gordon model., Comment: 21 pages, 8 figures; v2: minor changes to match version published in JHEP

В статье рассматриваются показатели, характеризующие возрастные структуры населения стран, входящих в Евразийский экономический союз. Проанализированы региональные различия возрастных структур, коэффициенты демографической нагрузки., The article discusses the indicators of age structure of the population of the countries included in the Eurasian economic Union. Analyzed regional differences in the age structures, the age dependency ratios.

The pairwise interaction energies of O–O and N–N in bcc metals of group VB, which were calculated earlier using first-principles methods, have been employed to analyze the effect of the interatomic interactions on the configurational contribution to the thermodynamic activity. The strong effect of interstitial- interstitial interaction has been shown. The configurational contribution grows in the row (Nb–N) → (V–N) → (Ta–N) → (Nb–O) → (V–O) → (Ta–O), which is caused by a weakening of the mutual attraction of interstitial atoms in these solid solutions. The strong repulsion that characterizes the majority of coordination shells only weakly affects the thermodynamic activity. The character of the temperature dependence of the configurational contribution is defined by the strength of the mutual attraction of the interstitial atoms, i.e., upon strong attraction, the contribution increases with increasing temperature (Nb–N, V–N, Ta–N, and Nb–O) and, upon weak attraction, it decreases (V–O and Ta–O)., QC 20170609

The influence of the temperature and sort of alloying element on the deformation of the nanocrystalline (NC) binary Al alloys with segregation of 10.2 at% Ti, Co, or Mg over grain boundaries has been studied using the molecular dynamics. The deformation behavior of the materials has been studied in detail by the simulation of the shear deformation of various Al bicrystals with the grain-boundary segregation of impurity atoms, namely, Ti, Co, or Mg. The deformation of bicrystals with different grain orientation has been studied. It has been found that Co introduction into grain boundaries of NC Al has a strengthening effect due to the deceleration of the grain-boundary migration (GBM) and difficulty in the grain-boundary sliding (GBS). The Mg segregation at the boundaries greatly impedes the GBM, but stimulates the development of the GBS. In the NC alloy of Al–Ti, the GBM occurs actively, and the flow-stress values are close to the values characteristic of pure Al.

We study simultaneous collisions of two, three, and four kinks and antikinks of the $\phi^6$ model at the same spatial point. Unlike the $\phi^4$ kinks, the $\phi^6$ kinks are asymmetric and this enriches the variety of the collision scenarios. In our numerical simulations we observe both reflection and bound state formation depending on the number of kinks and on their spatial ordering in the initial configuration. We also analyze the extreme values of the energy densities and the field gradient observed during the collisions. Our results suggest that very high energy densities can be produced in multi-kink collisions in a controllable manner. Appearance of high energy density spots in multi-kink collisions can be important in various physical applications of the Klein-Gordon model., Comment: 21 pages, 8 figures; v2: minor changes to match version published in JHEP

The influence of the temperature and sort of alloying element on the deformation of the nanocrystalline (NC) binary Al alloys with segregation of 10.2 at% Ti, Co, or Mg over grain boundaries has been studied using the molecular dynamics. The deformation behavior of the materials has been studied in detail by the simulation of the shear deformation of various Al bicrystals with the grain-boundary segregation of impurity atoms, namely, Ti, Co, or Mg. The deformation of bicrystals with different grain orientation has been studied. It has been found that Co introduction into grain boundaries of NC Al has a strengthening effect due to the deceleration of the grain-boundary migration (GBM) and difficulty in the grain-boundary sliding (GBS). The Mg segregation at the boundaries greatly impedes the GBM, but stimulates the development of the GBS. In the NC alloy of Al–Ti, the GBM occurs actively, and the flow-stress values are close to the values characteristic of pure Al.

Investigation of the thermoelastic martensitic transformation is of high interest nowadays because of the numerous applications of the materials with such structural peculiarities. Thermodynamics, kinetics, structure, morphology of martensitic transformation still remain unclear in many respects. From this point of view, the effective way to study various properties of metallic crystals on atomistic level is molecular dynamics simulation, for which good qualitative agreement with the experiment can be achieved even with simple Morse or Lennard-Jones interatomic potentials. In this paper, the effect of dislocations on the direct and reverse martensitic transformation is studied by molecular dynamics simulation in a two-dimensional model of the ordered alloy with the AB stoichiometry. The three dimensional analog to this structure is B2 superstructure based on bcc lattice, which is characteristic for intermetallic NiTi alloy. It is found, that the dislocations can be considered as the nucleation centers for martensite phase, increasing the temperature of the direct martensitic transformation in comparison with the homogeneous martensitic transformation. The martensite domains found in the structure after transformation and the reverse martensitic transformation takes place in the presence of the domain boundaries, meaning that the austenite nucleates heterogeneously. At the reverse transformation, splitting of perfect dislocations into partials dislocations took place. Thus, it was established in the present study that, on the one hand, dislocations affect the direct martensitic transformation as the nucleation centers, and from the other hand, reverse martensitic transformation changes the dislocation structure of the modeled alloy. © 2017, Institute for Metals Superplasticity Problems of Russian Academy of Sciences. All rights reserved., MD simulation of direct and reverse MT in the framework of the 2D model of an ordered alloy shows that dislocations can be considered as the nucleation centers of martensite during direct MT. In the absence of dislocations, martensite nucleates homogeneously at lower temperatures. The reverse MT occurs in the presence of twinned martensite and domain walls in the system, which means that even in the absence of dislocations, the structure of the alloy is not ideal. During the reverse MT, the perfect dislocations split into partial dislocations. It should be noted that for selected model parameters MT is associated with large lattices deformations, therefore, temperature hysteresis is also large, which is not typical for SM alloys. However, the consideration of the Acta Mater. 95, 37 (2015). effects of SM and superelasticity is not prohibited in frame of 14. C. Ni, H. Ding, XJ.. Jin. J. Alloys Compd. 546, 1 (2013). this model, since the degree of coherence of the martensite 15. S. Kazanc, FA. . Celik, S. Ozgen. J. Phys. Chem. Solids. 74, and austenite lattices is quite high. One of the important 1836 (2013). problems for futher investigations is the studying of the MT 16. T. Suzuki, M. Shimno, K. Otsuka, X. Ren, A. Saxena. as the detonation process [36]. J. Alloys Compd. 577S, S113 (2013). 17. B. Wang, E. Sak-Saracino, N. Gunkelmann, Aknowledgements. S.V. D. acknowledges support from the H.M. Urbassek. Comp. Mater. Sci. 82, 399 (2014). Russian Foundation for Basic Research, grant No. 16-58-48001 18. C. Tatar, S. Kazanc. Current Applied Physics. 12, 98 IND_omi (design of the research, discussion of the results). (2012). J.A. B and V.G. P. are grateful for the financial support from 19. A.R. Kuznetsov, Yu.N. Gornostyrev, M.I. Katsnelson, the Russian Science Foundation, grant No. 15-12-10014 A. V. Trefilov. Mater. Sci Eng. A309–311068 (2001). (numerical simulations and writing the paper). R.I. B. thanks 20. I.N. Kar’kin, Yu.N. Gornostyrev, L.E. Kar’kina.

Investigation of the thermoelastic martensitic transformation is of high interest nowadays because of the numerous applications of the materials with such structural peculiarities. Thermodynamics, kinetics, structure, morphology of martensitic transformation still remain unclear in many respects. From this point of view, the effective way to study various properties of metallic crystals on atomistic level is molecular dynamics simulation, for which good qualitative agreement with the experiment can be achieved even with simple Morse or Lennard-Jones interatomic potentials. In this paper, the effect of dislocations on the direct and reverse martensitic transformation is studied by molecular dynamics simulation in a two-dimensional model of the ordered alloy with the AB stoichiometry. The three dimensional analog to this structure is B2 superstructure based on bcc lattice, which is characteristic for intermetallic NiTi alloy. It is found, that the dislocations can be considered as the nucleation centers for martensite phase, increasing the temperature of the direct martensitic transformation in comparison with the homogeneous martensitic transformation. The martensite domains found in the structure after transformation and the reverse martensitic transformation takes place in the presence of the domain boundaries, meaning that the austenite nucleates heterogeneously. At the reverse transformation, splitting of perfect dislocations into partials dislocations took place. Thus, it was established in the present study that, on the one hand, dislocations affect the direct martensitic transformation as the nucleation centers, and from the other hand, reverse martensitic transformation changes the dislocation structure of the modeled alloy. © 2017, Institute for Metals Superplasticity Problems of Russian Academy of Sciences. All rights reserved., MD simulation of direct and reverse MT in the framework of the 2D model of an ordered alloy shows that dislocations can be considered as the nucleation centers of martensite during direct MT. In the absence of dislocations, martensite nucleates homogeneously at lower temperatures. The reverse MT occurs in the presence of twinned martensite and domain walls in the system, which means that even in the absence of dislocations, the structure of the alloy is not ideal. During the reverse MT, the perfect dislocations split into partial dislocations. It should be noted that for selected model parameters MT is associated with large lattices deformations, therefore, temperature hysteresis is also large, which is not typical for SM alloys. However, the consideration of the Acta Mater. 95, 37 (2015). effects of SM and superelasticity is not prohibited in frame of 14. C. Ni, H. Ding, XJ.. Jin. J. Alloys Compd. 546, 1 (2013). this model, since the degree of coherence of the martensite 15. S. Kazanc, FA. . Celik, S. Ozgen. J. Phys. Chem. Solids. 74, and austenite lattices is quite high. One of the important 1836 (2013). problems for futher investigations is the studying of the MT 16. T. Suzuki, M. Shimno, K. Otsuka, X. Ren, A. Saxena. as the detonation process [36]. J. Alloys Compd. 577S, S113 (2013). 17. B. Wang, E. Sak-Saracino, N. Gunkelmann, Aknowledgements. S.V. D. acknowledges support from the H.M. Urbassek. Comp. Mater. Sci. 82, 399 (2014). Russian Foundation for Basic Research, grant No. 16-58-48001 18. C. Tatar, S. Kazanc. Current Applied Physics. 12, 98 IND_omi (design of the research, discussion of the results). (2012). J.A. B and V.G. P. are grateful for the financial support from 19. A.R. Kuznetsov, Yu.N. Gornostyrev, M.I. Katsnelson, the Russian Science Foundation, grant No. 15-12-10014 A. V. Trefilov. Mater. Sci Eng. A309–311068 (2001). (numerical simulations and writing the paper). R.I. B. thanks 20. I.N. Kar’kin, Yu.N. Gornostyrev, L.E. Kar’kina.

In the framework of strong field QED, the generation of a residual alternating polarization current is demonstrated, which remains after switching off an external field pulse. This effect is stipulated by inertial properties of the physical vacuum. In the standard vacuum D = 2+1 QED, this current is rapidly damped fast but can be available, apparently, for observation in the graphene, where the Fermi velocity vF << c plays an analogous role as the light velocity.

Creation of miniature optical delay lines and buffers is one of the greatest challenges of the modern photonics which can revolutionize optical communications and computing. Several remarkable designs of slow light optical delay lines employing coupled ring resonators and photonic crystal waveguides has been suggested and experimentally demonstrated. However, the insertion loss of these devices is too large for their practical applications. Alternatively, the recently developed photonic fabrication platform, Surface Nanoscale Axial Photonics (SNAP) allows us to fabricate record small delay lines with unprecedentedly small dispersion and low loss. In this report, we review the recent progress in fabrication and design of miniature slow light devices and buffers, in particular, those based on the SNAP technology.

Creation of miniature optical delay lines and buffers is one of the greatest challenges of the modern photonics which can revolutionize optical communications and computing. Several remarkable designs of slow light optical delay lines employing coupled ring resonators and photonic crystal waveguides has been suggested and experimentally demonstrated. However, the insertion loss of these devices is too large for their practical applications. Alternatively, the recently developed photonic fabrication platform, Surface Nanoscale Axial Photonics (SNAP) allows us to fabricate record small delay lines with unprecedentedly small dispersion and low loss. In this report, we review the recent progress in fabrication and design of miniature slow light devices and buffers, in particular, those based on the SNAP technology.

A method of precise characterization of surface nanoscale axial photonics (SNAP) structures with a reference fiber is proposed, analyzed, and demonstrated experimentally. The method is based on simultaneous coupling of a microfiber to a SNAP structure under test and to a reference optical fiber. Significant reduction of measurement errors associated with the environmental temperature variations and technical noise of the spectrum analyzer is demonstrated. The achieved measurement precision of the effective radius variation of the SNAP structure is 0.2 Å.

A method of precise characterization of surface nanoscale axial photonics (SNAP) structures with a reference fiber is proposed, analyzed, and demonstrated experimentally. The method is based on simultaneous coupling of a microfiber to a SNAP structure under test and to a reference optical fiber. Significant reduction of measurement errors associated with the environmental temperature variations and technical noise of the spectrum analyzer is demonstrated. The achieved measurement precision of the effective radius variation of the SNAP structure is 0.2 Å.

A method of precise characterization of surface nanoscale axial photonics (SNAP) structures with a reference fiber is proposed, analyzed, and demonstrated experimentally. The method is based on simultaneous coupling of a microfiber to a SNAP structure under test and to a reference optical fiber. Significant reduction of measurement errors associated with the environmental temperature variations and technical noise of the spectrum analyzer is demonstrated. The achieved measurement precision of the effective radius variation of the SNAP structure is 0.2 Å.

Creation of miniature optical delay lines and buffers is one of the greatest challenges of the modern photonics which can revolutionize optical communications and computing. Several remarkable designs of slow light optical delay lines employing coupled ring resonators and photonic crystal waveguides has been suggested and experimentally demonstrated. However, the insertion loss of these devices is too large for their practical applications. Alternatively, the recently developed photonic fabrication platform, Surface Nanoscale Axial Photonics (SNAP) allows us to fabricate record small delay lines with unprecedentedly small dispersion and low loss. In this report, we review the recent progress in fabrication and design of miniature slow light devices and buffers, in particular, those based on the SNAP technology.

Creation of miniature optical delay lines and buffers is one of the greatest challenges of the modern photonics which can revolutionize optical communications and computing. Several remarkable designs of slow light optical delay lines employing coupled ring resonators and photonic crystal waveguides has been suggested and experimentally demonstrated. However, the insertion loss of these devices is too large for their practical applications. Alternatively, the recently developed photonic fabrication platform, Surface Nanoscale Axial Photonics (SNAP) allows us to fabricate record small delay lines with unprecedentedly small dispersion and low loss. In this report, we review the recent progress in fabrication and design of miniature slow light devices and buffers, in particular, those based on the SNAP technology.

A method of precise characterization of surface nanoscale axial photonics (SNAP) structures with a reference fiber is proposed, analyzed, and demonstrated experimentally. The method is based on simultaneous coupling of a microfiber to a SNAP structure under test and to a reference optical fiber. Significant reduction of measurement errors associated with the environmental temperature variations and technical noise of the spectrum analyzer is demonstrated. The achieved measurement precision of the effective radius variation of the SNAP structure is 0.2 Å.

The Multipurpose Detector (MPD) \cite{cite1.MPD_CDR} is designed to study of hot and dense baryonic matter in collisions of heavy ions over the atomic mass range 1--197 at the centre of mass energy up to $\sqrt{S_{NN}}$ = 11 GeV (for Au79+). The MPD experiment will be carried out at the JINR accelerator complex NICA \cite{cite2.NICA_CDR} which is under construction. The barrel part of the MPD consists of various detectors surrounding the interaction point. It includes a precise tracking system (time projection chamber (TPC) and silicon inner tracker (IT)) and high-performance particle identification system based on time-of-flight (TOF) and calorimeter (ECal). The triple-stack multigap resistive plate chamber is chosen as an active element of the TOF. It provides good time resolution and long term stability. This article presents parameters of the MRPC obtained using the deuteron beam of JINR accelerator Nuclotron. The time resolution is $\sim$40 ps with efficiency of 99\%. Rate capability studies resulted with a time resolution of 60 ps and efficiency higher than 90\% on the beam with particle flux densities up to 2 kHz/cm$^2$., Comment: 8 pages, 10 figures, Proceedings of the XIII Workshop on Resistive Plate Chambers and Related Detectors (RPC2016), February 22 - 26, 2016, Ghent, Belgium

В статье проанализирован по ряду параметров командный состав полевых полков Сибирского корпуса второй половины 1760-х гг. с целью определить особенности имперской государственной политики в сфере комплектования вооруженных сил страны. На основе изучения архивных материалов выяснено, что при численном преобладании среди офицеров лиц, происходивших из дворян, многие из них принадлежали к мелкопоместному дворянству, что в значительной степени стирало дистанцию между ними и их подчиненными, выходцами из тяглых сословий. Комплектование полков Сибирского корпуса людьми, обладавшими служебным стажем и боевым опытом, объясняется существованием реальной угрозы военного столкновения с Китаем., The article analyzes a number of aspects connected with the commanding officers of the field troops of the Siberian Corps of the 2nd half of the 1760s to determine the peculiarities of the imperial state policy in the sphere of recruitment of the armed forces of the country. With reference to a number of archival materials, the author comes to the conclusion that while outnumbering recruits from other social classes, officers from the nobility were mainly from the small gentry which considerably bridged the gap between them and their subordinates, representatives of taxed classes. The recruitment of people with work and military experience into the Siberian Corps can be explained by the real threat of a military conflict with China.

Computer simulations in the framework of the Density Functional Theory have become an established tool for computer simulations of materials properties. In most cases, however, information is obtained at ambient conditions, preventing design of materials for applications at extreme conditions. In this work we employ ab initio calculations to investigate the influence of stresses on structure and stability of Ti-Mo and Zr-Nb alloys, an important class of construction materials. Calculations reproduce known phase stability trends in these systems, and we resolve the controversy regarding the stability of body-centered cubic solid solution in Mo-rich Ti-Mo alloys against the isostructural decomposition. Calculated results are explained in terms of the electronic structure effects, as well as in terms of physically transparent thermodynamic arguments that relate phase stability to deviations of concentration dependence of atomic volume from the linear behavior.

Accepted: 2010-05-12

One of the most sought-after objects in topological quantum matter systems is a vortex carrying half a quantum of circulation. They were originally predicted to exist in superfluid 3He-A, but have never been resolved there. Here we report an observation of half-quantum vortices (HQVs) in the polar phase of superfluid 3He. The vortices are created with rotation or by the Kibble-Zurek mechanism and identified based on their nuclear magnetic resonance signature. This discovery provides a pathway for studies of unpaired Majorana modes bound to the HQV cores in the polar-distorted A phase., Comment: 10 pages, 6 figures, version accepted to Phys. Rev. Lett

One of the most sought-after objects in topological quantum matter systems is a vortex carrying half a quantum of circulation. They were originally predicted to exist in superfluid 3He-A, but have never been resolved there. Here we report an observation of half-quantum vortices (HQVs) in the polar phase of superfluid 3He. The vortices are created with rotation or by the Kibble-Zurek mechanism and identified based on their nuclear magnetic resonance signature. This discovery provides a pathway for studies of unpaired Majorana modes bound to the HQV cores in the polar-distorted A phase., Comment: 10 pages, 6 figures, version accepted to Phys. Rev. Lett

Computer simulations in the framework of the Density Functional Theory have become an established tool for computer simulations of materials properties. In most cases, however, information is obtained at ambient conditions, preventing design of materials for applications at extreme conditions. In this work we employ ab initio calculations to investigate the influence of stresses on structure and stability of Ti-Mo and Zr-Nb alloys, an important class of construction materials. Calculations reproduce known phase stability trends in these systems, and we resolve the controversy regarding the stability of body-centered cubic solid solution in Mo-rich Ti-Mo alloys against the isostructural decomposition. Calculated results are explained in terms of the electronic structure effects, as well as in terms of physically transparent thermodynamic arguments that relate phase stability to deviations of concentration dependence of atomic volume from the linear behavior.

Computer simulations in the framework of the Density Functional Theory have become an established tool for computer simulations of materials properties. In most cases, however, information is obtained at ambient conditions, preventing design of materials for applications at extreme conditions. In this work we employ ab initio calculations to investigate the influence of stresses on structure and stability of Ti-Mo and Zr-Nb alloys, an important class of construction materials. Calculations reproduce known phase stability trends in these systems, and we resolve the controversy regarding the stability of body-centered cubic solid solution in Mo-rich Ti-Mo alloys against the isostructural decomposition. Calculated results are explained in terms of the electronic structure effects, as well as in terms of physically transparent thermodynamic arguments that relate phase stability to deviations of concentration dependence of atomic volume from the linear behavior.

Computer simulations in the framework of the Density Functional Theory have become an established tool for computer simulations of materials properties. In most cases, however, information is obtained at ambient conditions, preventing design of materials for applications at extreme conditions. In this work we employ ab initio calculations to investigate the influence of stresses on structure and stability of Ti-Mo and Zr-Nb alloys, an important class of construction materials. Calculations reproduce known phase stability trends in these systems, and we resolve the controversy regarding the stability of body-centered cubic solid solution in Mo-rich Ti-Mo alloys against the isostructural decomposition. Calculated results are explained in terms of the electronic structure effects, as well as in terms of physically transparent thermodynamic arguments that relate phase stability to deviations of concentration dependence of atomic volume from the linear behavior.

Computer simulations in the framework of the Density Functional Theory have become an established tool for computer simulations of materials properties. In most cases, however, information is obtained at ambient conditions, preventing design of materials for applications at extreme conditions. In this work we employ ab initio calculations to investigate the influence of stresses on structure and stability of Ti-Mo and Zr-Nb alloys, an important class of construction materials. Calculations reproduce known phase stability trends in these systems, and we resolve the controversy regarding the stability of body-centered cubic solid solution in Mo-rich Ti-Mo alloys against the isostructural decomposition. Calculated results are explained in terms of the electronic structure effects, as well as in terms of physically transparent thermodynamic arguments that relate phase stability to deviations of concentration dependence of atomic volume from the linear behavior.