bluuebunny/crossref_metadata_2025 huggingface dataset:
RanGTP induces an effector gradient of XCTK2 and importin α/β for spindle microtubule cross-linking
Authors: Ems-McClung Stephanie C. , Emch Mackenzie , Zhang Stephanie , Mahnoor Serena , Weaver Lesley N. , Walczak Claire E.
Published: December 2019

High RanGTP around chromatin is important for governing spindle assembly during meiosis and mitosis by releasing the inhibitory effects of importin α/β. Here we examine how the Ran gradient regulates Kinesin-14 function to control spindle organization. We show that Xenopus Kinesin-14, XCTK2, and importin α/β form an effector gradient that is highest at the poles and diminishes toward the chromatin, which is opposite the RanGTP gradient. Importin α and β preferentially inhibit XCTK2 antiparallel microtubule cross-linking and sliding by decreasing the microtubule affinity of the XCTK2 tail domain. This change in microtubule affinity enables RanGTP to target endogenous XCTK2 to the spindle. We propose that these combined actions of the Ran pathway are critical to promote Kinesin-14 parallel microtubule cross-linking to help focus spindle poles for efficient bipolar spindle assembly. Furthermore, our work illustrates that RanGTP regulation in the spindle is not simply a switch, but rather generates effector gradients where importins α and β gradually tune the activities of spindle assembly factors.
Comparison BIPM.RI(I)-K6 of the standards for absorbed dose to water of the KRISS, Korea and the BIPM in accelerator photon beams
Authors: Kessler C , Burns D T , Picard S , Roger P , Kim I J , Kim B C , Kim Y H , Kim J H , Chung J P , Yi C Y
Published: December 2019

A key comparison has been made between the absorbed dose to water standards of the KRISS, Korea and the BIPM in accelerator photon beams. The results show the standards to be in agreement within the expanded uncertainty (k = 2) of the comparison of 12 parts in 103. The results are analysed and presented in terms of degrees of equivalence, suitable for entry in the BIPM key comparison database.

Main text

To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/.

The final report has been peer-reviewed and approved for publication by the CCRI, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
Dynamical observation of mobility edges in one-dimensional incommensurate optical lattices
Authors: Xu Zhihao , Huangfu Hongli , Zhang Yunbo , Chen Shu
Published: December 2019

We investigate the wave packet dynamics for a one-dimensional incommensurate optical lattice with a special on-site potential which exhibits the mobility edge in a compactly analytic form. We calculate the density propagation, long-time survival probability and mean square displacement of the wave packet in the regime with the mobility edge and compare with the cases in extended, localized and multifractal regimes. Our numerical results indicate that the dynamics in the mobility-edge regime mix both extended and localized features which is quite different from that in the mulitfractal phase. We utilize the Loschmidt echo dynamics by choosing different eigenstates as initial states and sudden changing the parameters of the system to distinguish the phases in the presence of such system.
Entropy and mutual information in models of deep neural networks*
Authors: Gabrié Marylou , Manoel Andre , Luneau Clément , Barbier Jean , Macris Nicolas , Krzakala Florent , Zdeborová Lenka
Published: December 2019

We examine a class of stochastic deep learning models with a tractable method to compute information-theoretic quantities. Our contributions are three-fold: (i) we show how entropies and mutual informations can be derived from heuristic statistical physics methods, under the assumption that weight matrices are independent and orthogonally-invariant. (ii) We extend particular cases in which this result is known to be rigorously exact by providing a proof for two-layers networks with Gaussian random weights, using the recently introduced adaptive interpolation method. (iii) We propose an experiment framework with generative models of synthetic datasets, on which we train deep neural networks with a weight constraint designed so that the assumption in (i) is verified during learning. We study the behavior of entropies and mutual informations throughout learning and conclude that, in the proposed setting, the relationship between compression and generalization remains elusive.
The peculiarities of spectral dependences of the transverse Kerr effect of Au-Co nanostructures
Authors: Yurasov A N , Yashin M M , Ganshina E A , Mokrushina A A , Semenova D V
Published: December 2019

The paper is concerned with the experimental spectral dependence of the magneto-optic Kerr effect for samples of nano-layered films of Co-Au. Theoretical spectral dependences of the ‘Transversal Kerr Effect’ are constructed. Spectral dependences taking into account the size effect are given. Theoretical and experimental data are compared. There is good agreement between experimental and simulated results. The relevance of this research area and the results obtained are noted. Discussed the possibility of using such nano-layered thin films structures.
Molecular dynamics simulation of thermal diffusion processes in non-isothermal flow of the medium
Authors: Sidorov A V , Grabov V M , Zaitsev A A , Kuznetsov D V
Published: December 2019

The article presents a brief information on the discovery and experimental study of a new thermoelectrokinetic effect consisting in the formation of thermoelectrokinetic EMF in viscous conductive media in the presence of mass transfer (particles) and the action of a temperature gradient. On the basis of the molecular dynamics method, a mathematical model is developed and a numerical simulation of the non-isothermal flow of the Lennard-Jones fluid under the conditions of thermoelectrokinetic effect formation is carried out. As a result of the simulation the microscopic regularities of its formation are established.
Study of irreversible degradation processes in gate dielectric of MIS structures
Authors: Andreev D V , Stolyarov A A , Andreev V V , Tsarkov A V
Published: December 2019

In this paper we propose an improved method for accelerated tests of the MIS structure gate dielectric and for studying the irreversible processes in it. This method is based on applying a ramping current load to a sample with a short injection measurement mode between the increments of the current load. This method allows obtaining a time history of the voltage drop across MIS structure at a constant level of measurement injection current for the whole current load range. This time history can be used to find the parameters characterizing irreversible processes of charge degradation such as density and localization of a charge accumulating in the dielectric film, cross-sections of electron and hole traps, nature of the evolution of charge effects and etc.
The research of time dependence polymeric membrane swelling in water with various deuterium content
Authors: Bunkin N F , Babushkin D P , Bereza I S , Bolikov N G , Bashkina U A , Tuan Vu Minh , Gudkov S V , Kozlov V A
Published: December 2019

Experiments on the Fourier transform spectrometry of Nafion, a water-swollen polymeric membrane, are described. The transmittance spectra of liquid samples and Nafion, soaked in these samples, were examined, depending on the deuterium content in water within the spectral range 1.8 - 2.15 μm. The experiments were carried out according to two protocols: with the first protocol we studied the dynamics of Nafion swelling in H2O + D2O mixtures for the deuterium concentrations 3 < C < 104 ppm, and with the second protocol we studied the dynamics of swelling in pure heavy water (C = 106 ppm). For liquid mixtures in the concentration range 3 < C < 104 ppm, the transmittance spectra are the same, but for Nafion soaked in these fluids, the corresponding spectra are different. It is shown that, in the range of deuterium contents C = 90 - 500 ppm, the behavior of transmittance of the polymer membrane is non-monotonic. In experiments with the second protocol, the dynamics of diffusion replacement of residual water, which is always present in the bulk of the polymer membrane inside closed cavities (i.e., without access to atmospheric air), was studied.
Modeling the underwater acoustic communication under ice cover on the Arctic shelf
Authors: Volkov M V , Kalinina T S , Lunkov A A , Petnikov V G
Published: December 2019

Numerical simulations of the underwater acoustic communication are carried out for a shallow water waveguide with a rough ice cover. The acoustic model is based on a coupled normal mode approach. Binary phase-shift keying is implemented to code the information. The bit error rate in an ice-free waveguide is found to be an order higher than in the case of a rough ice cover. The reason for that is the difference between impulse responses. The impulse response of the ice-covered channel is narrower than in the unperturbed case, which is due to the increased energy transfer from the lower modes to the higher, strongly attenuating modes
Response of macroscopic nonlocal correlation detector to a phase transition
Authors: Korotaev S M , Gorohov J V , Serdyuk V O , Novysh A V
Published: December 2019

Macroscopic entanglement represents itself in nonlocal correlation of the entropy productions of classically insulated dissipative processes. Nonlocal correlation detector is a device including some, well protected from any local impacts, spontaneous dissipative probe-process, the entropy variation in which is related with a measurable variable (signal). Experimentally convenient example of the source-process is a phase transition. The experiment on measuring of response of electrode macroscopic correlation detector to the process of liquid nitrogen evaporation has been carried out. The signal extremum is reached much later than the end of evaporation. The detector response begins at once as the evaporation beginning, while classical local temperature impact has retardation equal to 1.5 hours. The form of response is essentially asymmetric, with long relaxation time.
Novel Eu3+ complex based on β – diketonate ligand for OLED application
Authors: Korshunov V M , Ambrozevich S A , Kareva E R
Published: December 2019

It was demonstrated that bonding Eu3+ ion to β – diketonate ligand as main ligand and 4,7-Diphenyl-1,10-phenanthroline (bathophenanthroline) as ancillary ligand leads to a significant increase of extinction and luminescence intensity. To order the potential of this complex to OLED application, we fabricated and investigated the electroluminescent device based on this compound. We achieved a high value of photoluminescence quantum yield (56 %) and external quantum efficiency value of 1% at 12 V.
Simulation of the electrostatic fields in devices with complex geometric shapes
Authors: Sorokin D L , Skuybin B G , Galkin N K , Litvinov V N , Dushkin M A , Ryabokon M S
Published: December 2019

The problems of physical and mathematical simulation of electrostatic field were considered. The antetype of experimental assembly of field investigation was created. The calculation algorithm for numerical solution of the problem based on the mathematical model of the field and Green theorem was created. The algorithm was implemented as computer program. The results of the numerical and live experiments were obtained and compared.
Registration of patents for inventions and utility models by students of higher educational institutions
Authors: Ryabokon’ M S , Skuybin B G , Sorokin D L , Galkin N K
Published: December 2019

This article reviews detailed order of registration of patents for inventions and utility models. General issues of patenting are considered and specific recommendations on the preparation of patent application documents are given. The registration of patent is illustrated by the example of a laboratory setup for the demonstration of electrostatic fields, which was modernized by students of BMSTU in the Student Laboratory of Physics (SELP).
Dynamics of plasma piston composition
Authors: Gerasimov Yu V , Maslov A G , Kachesov A E , Melnikov V V
Published: December 2019

The article is devoted to the stratification of plasma formation in the railgun channel. The motion model for a composition of plasma pistons interacting with each other, rails and railgun walls was proposed. It was shown that the maximum impulse that could be transmitted to the throwing body in this system substantially depends on the initial position of the plasma pistons, according to the simulation results. The rational initial system configuration is obtained, at which the maximum value of the momentum transferred to the throwing body is reached. Possible options for obtaining such a configuration and a qualitative model of the stratification of a single plasma formation into several plasma pistons were proposed.
Mathematical model of the optical radiation propagation in the microsatellite moving in near-earth orbit
Authors: Gladyshev V O , Strunin A G , Sharandin E A , Sokolov A L , Murashkin V V , Beloklokova U I
Published: December 2019

The paper considers the problem of the laser radiation propagation from the Earth surface to a Luneburg lens moving at a speed V along a geosynchronous orbit, and the registration by a ground-based observer of radiation reflected by a lens. Preliminary calculations show that the beams reflected by the moving lens deviate at different angles, which leads to the mixing of the beams on the Earth’s surface in the region of the radiation recorded. That, in turn, affects the appearance of the interference pattern and the process of recording the radiation reflected by the lens. Therefore, the purpose of this work is to calculate the formed optical response in the reception area of the radiation, taking into account the optical effects of the moving media: the Fizeau effect, the Doppler effect, violation of the Snell’s law, the kinematic effect of the beam points displacement on the optical surface caused by the final velocity of radiation in the lens.
Experimental Approach for Obtaining a Complex (Dusty) Plasma Fluid
Authors: Yakovlev Egor V. , Ovcharov Pavel V. , Dukhopelnikov Dmitrii V. , Yurchenko Stanislav O.
Published: December 2019

An experimental approach is proposed to obtain a complex (dusty) plasma fluid. In contrast to previously employed laser heating of a complex (dusty) plasma crystal, this approach is based on the mode-coupling instability of the crystal and does not require any additional influence. We consider a typical experiment and report results of post-processing, including the Voronoi-cell area distribution and order parameter, justifying a liquid state of the system existing for a long enough time. The results can be useful for studies of phenomena and properties of fluids at different couplings, such as excitation spectra, density–density correlations, diffusion, and relations between them.
Developing specialized software for investigating interference in complex optical systems
Authors: Koziy Andrey , Minchenko Ilya , Alekhin Vladislav , Larin Roman , Kiktenko Evgeny
Published: December 2019

The paper describes a physical model and primary calculation algorithms we developed and implemented in a software package for simulating interference in complex optical systems. A model of a highly monochromatic laser beam interacting with various optical elements is proposed. We verified and validated our model by creating an interference pattern on a screen. Model verification involved an experiment with a Mach-Zehnder interferometer. Model validation consisted of simulating our own optical experiment.
Luminescent properties of nanocomposite - Bi12SiO20, filled with C6H9EuO6 × H2O
Authors: Moiseienko Vasyl N , Gorelik Vladimir S , Sal Bilal Abu , Ohiienko Oleh V , Golochalov Dmitro O
Published: December 2019

The work presents the results of the study of the photoluminescence spectra of the (111) growth surface of an opal - Bi12SiO20 matrix nanocomposite filled with europium (III) acetate hydrate (C6H9EuO6 × H2O). An increase in the integral luminescence intensity of the matrix composite opal - Bi12SiO20: Eu3+ compared to composite opal: Eu3+ was found. The measured photoluminescence spectra of the Bi3+ ions in the opal pores indicate its participation in optical processes as a co-activator of luminescence. A change in the character of the splitting of the main luminescence bands of Eu3+ ions in the region of 575–635 nm and the integral luminescence intensity after dehydration of the crystalline hydrate in opal pores has been established.
Cost-Efficient Numerical Schemes for the Boundary Integral Equation Solution in 2D Vortex Methods
Authors: Kuzmina Kseniia , Marchevsky Ilia , Moreva Victoriya , Ryatina Evgeniya
Published: December 2019

The problem of the flow simulation around airfoils using Lagrangian vortex methods is considered. Numerical schemes of the second order of accuracy for free vortex sheet intensity distribution along the airfoil are developed for smooth and non-smooth airfoils. The schemes are based on the Galerkin approach with piecewise-constant and piecewise-linear basis functions. The finite element method ideas are used and the resulting piecewise-linear scheme has the same numerical complexity as the scheme with piecewise-constant numerical solution. The modification of a FEM-type scheme is developed for non-smooth airfoils which permits to take into account the discontinuity of the solution at the specified points; its computational cost increases insignificantly.
Probability representation of quantum mechanics and star product quantization
Authors: Chernega V N , Belolipetskiy S N , Man’ko O V , Man’ko V I
Published: December 2019

This paper presents a review of star-product formalism. This formalism provides a description for quantum states and observables by means of the functions called’ symbols of operators’. Those functions are obtained via bijective maps of the operators acting in Hilbert space. Examples of the Wigner-Weyl symbols (Wigner quasi-distributions) and tomographic probability distributions (symplectic, optical and photon-number tomograms) identified for the states of the quantum systems are discussed. Properties of quantizer-dequantizer operators required for construction of bijective maps of two operators (quantum observables) onto the symbols of the operators are studied. The relationship between structure constants of associative star-product of operator symbols and quantizer-dequantizer operators is reviewed.
Mathematical modeling of the beam spatial distribution for the laser with ceramic active elements
Authors: Sharandin E A , Kauts V L , Gladysheva T M , Kaiutienko A V , Portnov D I
Published: December 2019

Numerical calculations of the formation of the radiation spatial distribution in the near field by laser amplifiers of pulsed solid-state lasers are performed. On the basis of mathematical modeling, a method is proposed for ensuring spatial homogeneity of laser radiation, based on the use of ceramic active elements with a non-uniform distribution of population inversion over the active element cross-section. The method allows for increasing the spatial homogeneity of laser beams of amplifiers operating in the saturated gain mode.
On the road to low temperature district heating
Authors: Cenian Adam , Dzierzgowski Mieczysław , Pietrzykowski Bartosz
Published: December 2019

The roadmap to implementation of low temperature (LT) grid taking into account existing district heating (DH) systems is analysed in the paper. Lessons learned from pilot cases in Albertslund, HojeTaastrup, Kalundborg and Łomża are presented. Also in Albertslund and Hoje Taastrup LTDH grids constituting subgrids of the main (third generation) DH grids, and the last is fed from the DH return-flow. In Kalundborg an independent ultra-LTDH grid is considered to utilize the low temperature surplus heat (around 20°C) as supply for Municipalities located nearby. In Poland the effects of a lower supply temperature in an entire DH grid were investigated. This lower supply temperature was effective on account of the existing DH-grid infrastructure being oversized.
Modelling of hydrogen flame in perfectly clean combustion regimes using LES-CMC
Authors: Wawrzak Agnieszka , Tyliszczak Artur
Published: December 2019

The LES coupled with the first-order CMC method and detailed chemical mechanism is used for the calculations of hydrogen jet burning in the atmosphere of water vapour and oxygen mixture. The flame is initiated by a spark, then it spreads and propagates through the domain and eventually stabilises as a lifted or attached one. Three dimensional calculations were proceeded with analysis of the flame in the mixture fraction space. The main focus of the paper is on the effect of oxidizer composition on the flame characteristics and stabilization mechanisms. The flame structure during the propagation phase is represented based on the so-called pre-ignition species. Time-averaged results show the flame lift-off distance, shape and radial size. It is found that these factors may be effectively controlled by the amount of water vapour in the co-flowing oxidizer.
Sustainable utilization of the sewage sludge using combined drying, torrefaction and plasma gasification technologies
Authors: Pawlak-Kruczek Halina , Czerep Michał , Ostrycharczyk Michał , Wnukowski Mateusz , Baranowski Marcin , Krochmalny Krystian , Niedzwiecki Lukasz , Kowal Mateusz
Published: December 2019

This paper presents complete mass and energy balance of a novel installation for thermal utilization of the sewage sludge. Calculations were performed for the typical output of a wastewater processing plant in a middle size Polish town. Overall, the proposed configuration seems to be advantageous, as the proposed installation is fully sustainable and does not need external energy sources, due to maximized heat recovery from many different sources. Optimization of the heat use is performed, by utilizing all the available heat sources, including low-quality heat, such as the latent heat of water vapors, present in wet air after drying. Despite using plasma gasification system, the installation is able to generate surplus electricity, which can be used as a power source for all of the auxiliary devices, such as fans, augers and PLC systems. The proposed system can be implemented in the water treatment plants, in towns with the total amount of inhabitants ranging from a couple of thousand up to 40 thousand. System does not require anaerobic digestion of the sewage sludge. Nonetheless, the use of anaerobic digestion brings some advantages as the producer gas from the gasification installation can be mixed with biogas.
New polymorphic varieties of fluorographene forming during fluorine functionalization of 4-8 graphene layers
Authors: Belenkov Maxim E , Chernov Vladimir M , Belenkov Evgeny A
Published: December 2019

Using the methods of the density functional theory in the generalized gradient approximation, the structure and electronic properties of six new polymorphic varieties of fluorographene, formed during the chemical adsorption of fluorine by a 4-8 graphene layer, are calculated. The sublimation energy of 4-8 polymorphs of fluorographene varies from 13.36 to 14.09 eV (CF)-1. The range of variation of the band gap of new CF-L4-8 polymorphs of fluorographene is greater than the similar interval for CF-L6 compounds.
Cylindrical thermal invisibility cloak based on transformation thermodynamics
Authors: Soboleva V Y , Tukmakova A S , Sharaevsky M V , Vozianova A V , Khodzitsky M K
Published: December 2019

The paper provides a theoretical proof that the methods of transformation optics can be used for thermodynamics. Thermal conductivity tensor is calculated for the development of the thermal invisibility cloak, which directs the heat flux around a certain area. The finite element method was used to simulate the cloak with parameters close to real. The simulation was performed by the finite element method for two cases: with gradient k and with copper/mica layered structure.
Structure and electronic properties of 4-8 and 4-6-12 layered varieties of boron nitride
Authors: Ryashentsev Dmitry S , Belenkov Evgeny A
Published: December 2019

The structure of two new layered polymorphic varieties of boron nitride was calculated by the density functional theory method using the gradient approximation. The structure of layers BN-L4-8 and BN-L4-6-12 differs from the structure of the hexagonal layer of boron nitride in that their surface is formed not only from hexagons. As a result of the calculations, it was found that the sublimation energy of the new layers (17.36 and 17.14 eV (BN)-1 for the layers BN-L4-8 and BN-L4-6-12, respectively) is less than the sublimation energy of hexagonal boron nitride ( 18.14 eV (BN)-1). The band gap of new boron nitride polymorphs is about 3.9 eV, which is less than the calculated width of the band gap in BN-L6 – 4.69 eV.
Synthesis and transport properties of FET based on Heusler alloy thin films formed by rapid thermal annealing
Authors: Lukyanenko A V , Tarasov A S , Shanidze L V , Yakovlev I A , Zelenov F V , Masugin A N , Ivanov A B , Baron F A , Volkov N V
Published: December 2019

In this work we show a preparation technique of Co2FeSi full-Heusler alloy thin films on silicon-on-insulator (SOI) substrates, employing rapid thermal annealing (RTA). The films of the Co2FeSi alloy were formed by a silicidation reaction, caused by RTA, between the ultrathin SOI (001) layer and the Fe/Co layers deposited on it. It is assumed that this technology is compatible with the process of formation of a half-metal source-drain in an advanced CMOS and SOI technology and will be applicable for the manufacture of a source-drain of a field-effect transistor. Schottky barrier field-effect transistors (FET) with a back-gate, based on silicon nanowires with source and drain of a Co2FeSi film, synthesized on an SOI substrate, were manufactured. The transport properties of the device were investigated.
Low-dimensional heterostructures obtaining from an intelligent material and carbon material on a silicon
Authors: Gurin S. A. , Pecherskaya E. A. , Fimin A.B. , Nikolaev K.O. , Shepeleva Y.V. , Artamonov D.V.
Published: December 2019

The results of the study of the technological regimes of the formation of a microcantilever beam of layered heterostructures based on the integration of smart material and silicon carbide are presented. Layers of silicon dioxide (SiO2), silicon nitride, silicon carbide, and platinum (lower electrode) are successfully formed on a silicon substrate. The results of an experimental study of the Pt / PZT / Pt / SiC heterostructures parameters confirmed the technological compatibility of the layers and the promise of using these structures in sensors of dynamic deformation when creating new generation sensors, including those operating in heavy rocket conditions of space technology.
Suppression of Stark effect in ultra-thin stress-free GaN/AlN multiple quantum well structures grown by plasma-assisted molecular beam epitaxy
Authors: Koshelev O A , Nechaev D V , Brunkov P N , Orekhova K N , Troshkov S I , Ivanov S V , Jmerik V N
Published: December 2019

We report on suppression of the Stark effect in (1.5-2)-monolayer(ML)-thick (GaN/AlN)100 multiple quantum well (MQW) structures grown on AlN/c-Al2O3 templates by plasma-assisted molecular beam epitaxy. Different stress relaxation mechanisms are revealed in these structures by using a multi-beam optical stress sensor in comparison with the 5ML-MQW structure. The former (with well thicknesses ⩽2MLs) demonstrate the nearly stress-free growth, whereas the latter structure with thicker wells exhibits the slow stress evolution from the high initial compressive stress to the nearly relaxed state with zero stress. Moreover, the former structures demonstrate a bright room-temperature cathodoluminescence (CL) with the single peak at the shortest wavelength 240 nm (1.5ML-QWs), while the latter shows much weaker multi-peak CL spectra in the spectral range of 270-360 nm.
Effects of plasma on the formation of bulk nanoscale structures with lateral dimensions on the surface of GaAs
Authors: Klimin V S , Rezvan A A , Solodovnik M S , Tominov R V , Ageev O A
Published: December 2019

In this work, the effect of plasma on the formation of bulk nanoscale structures with lateral dimensions on the GaAs surface was studied. The relative change in the area of the bulk structures in different crystallographic directions is demonstrated, in comparing the before and after the operations of modification and profiling with a successive change in the etching time from 0.5 to 2 minutes. The obtained data in the course of the study showed that when applying this technology for producing nanoscale structures, it is necessary to take into account a number of parameters, such as the crystallographic direction of the substrate, the etching time, and the formation voltage of oxide nanostructures.
Chemical synthesis and optical properties of composite materials containing PbI2 nanoparticles
Authors: Kulagina A S , Evstropiev S K , Saratovskii A S
Published: December 2019

The aqueous sols and composite organic-inorganic coatings containing PbI2 nanoparticles (size ∼ 4 nm) have been prepared. The absorption, photoluminescence and nonlinear transmittance (at 532 nm wavelength) have been studied. The electronic absorption spectra of PbI2/PVP sols showed major peak of ground state near 406 nm, which slightly blue shift with decreasing size. Obtained materials are characterized high transparency in visible spectral range and demonstrate quantum confinement effect. PbI2/PVP composite films manifested dependence of radiation resistance with PVP content at ns-laser exposure and size dependence of nonlinear transmittance.
Estimation of particle size using the Debye equation and the Scherrer formula for polyphasic TiO2 powder
Authors: Bokuniaeva A O , Vorokh A S
Published: December 2019

There are two methods to estimate the particle size from X-ray diffraction data: the Debye equation and the Scherrer formula. The main goal of this study is to describe the methodology of particle size estimation on the base of two these methods and to apply it to TiO2 powder to determine the diameters and the mass content of anatase and brookite components. The studied nano-dispersed TiO2 powder was synthesized by the sol-gel method. The proposed method of particle size estimation consists of several steps: 1. Approximation of diffraction peaks by Gaussians and calculation of initial values of particle size with the use of the Scherrer formula; 2. Iterations with the use of the Debye equation to obtain more accurate particle size values; 3. Calculation of the mass content of different components corresponding to the minimum R-factor.
Improvement of properties of cellulose dielectrics by their structure modification with nanocellulose produced of wastes of agricultural crops
Authors: Zhuravleva N , Reznik A , Kiesewetter D , Stolpner A , Smirnova E , Budaeva V
Published: December 2019

A comparative study of laboratory castings of insulating paper was fulfilled: the traditional composition made of insulating cellulose of pine and cellulose, modified with the nanocellulose of the agricultural waste (composite). The positive effect of the introduction of this structure-forming modifier on the electrical and mechanical strength of the cellulose dielectric, as well as its heat resistance was revealed. Confirmation of expediency of development of works of this direction for expansion of raw material base for producing of the bio component promoting increase of working capacity of the cellulose dielectrics used in high-voltage insulation of power devices is received.
Automated pulmonary nodule detection system in computed tomography images based on Active-contour and SVM classification algorithm
Authors: Shariaty F , Davydov V V , Yushkova V V , Glinushkin A P , Rud V Yu
Published: December 2019

Lung cancer is a common type of cancer that requires early diagnosis. Computer systems by particular different image processing techniques can use for increase the speed and accuracy of lung nodule detection. CT images used in this work in order to process medical images. In this paper proposed an automatic lung nodule detection algorithm using active contour method and SVM classification method. In proposed method, at first in order to achieve better results, lung CT image pre-processing is performed. Then the lung area is segmented by thresholding method followed by some reconstruction techniques to transfer non-isolated nodules into isolated ones. In the next step the nodule candidates are determined using active contour method. Then, nodules are detected by the support vector machine (SVM) classifier using efficient 2D stochastic and 3D anatomical features. In the result, nodules are detected with an overall detection rate of 87%; the number of false positive is 7.5/scan and the location of all detected nodules are recognized correctly.
Spectral method for determining quantum wells thickness and the composition in strained heterostructures GaAs/InGaAs
Authors: Pavlov N V , Evstropov V V , Mintairov M A , Mintairov S A , Kalyuzhnyy N A
Published: December 2019

A spectral method for determining the composition and width of quantum wells in strained GaAs/InGaAs heterostructures, based on the effect of separating of radiation absorption peaks of light and heavy holes, is proposed. Within the framework of the Van de Walle and Krijn model-solid theory for the band edges calculating based on the Bir and Pikus theory of deformation potentials, graphical and numerical methods were developed for determining the composition and width of the GaAs/InGaAs quantum wells with an indium content of around 0.4.
Experimental study of power-limiting factors of 1.1 μm range edge-emitting lasers based on InGaAs/GaAs quantum well-dot nanostructures
Authors: Serin A A , Payusov A S , Kornyshov G O , Shernyakov Yu M , Mintairov S A , Kalyuzhnyy N A , Kulagina M M , Zhukov A E , Gordeev N Yu , Maximov M V
Published: December 2019

We present a study of high-power characteristics of edge-emitting lasers based on quantum well-dots (QWD) in a pulsed regime. QWD-based lasers with 2 and 5 active layers emitting at ∼1.1 μm provided maximal optical power of 39 W limited by the pulse current source available. We have investigated the lasing spectra and shown that under the injection current above 20 kA/cm2 the active region overheats approximately by 0.5°C per 1 kA/cm2 during 100 ns current pulse. The active region overheating correlates well with the reducing of the differential efficiency of our devices. We believe that maximal pulse optical power of the QWD-based lasers is limited mainly by our laser wafer design rather than by the QWD active media properties.
New optical method for studying a magnetic track from a moving object
Authors: Logunov S E , Davydov V V , Glinuchkin A P , Podkovyrov I Yu , Rud’ V Yu
Published: December 2019

A new method for detecting a magnetic track from a moving magnetic object is presented. A technique has been developed to study the nature of changes in the magnetic field in a magnetic track using ferromagnetic fluid. The results of experimental studies are presented.
Tunable upconversion luminescence of SrF2: Er,Tm phosphors
Authors: Lyapin A A , Gushchin S V , Kuznetsov S V , Ermakov A S , Ryabochkina P A , Proydakova V Yu , Voronov V V , Yapryntsev A D , Ivanov V K , Fedorov P P
Published: December 2019

In preset paper, for the first time upconversion luminescence (UCL) of SrF2:Er,Tm phosphors upon excitation of 4I13/2 level of Er3+ were investigated. Fluorite-type SrF2:Er,Tm phosphors were synthesized by co-precipitation from aqueous nitrate solution technique. Tuning the UCL by SrF2:Er through Tm3+ ions co-doping was demonstrated. Also we estimated the UCL energy yield in the visible and near-infrared spectral range.
Spectroscopic study of defect states in CdSe nanoplatelets
Authors: Miropoltsev M A , Gromova Y A , Smelov V N , Cherevkov S A , Kormilina T K , Tkach A P , Maslov V G
Published: December 2019

Here we report investigation of red-shifted defect photoluminescence observed in two-dimensional colloidal cadmium selenide nanoplatelets. We used absorption, photoluminescence and photoluminescence excitation measurements to show that red-shifted photoluminescence bands are related directly to nanoplatelets and may originate from surface imperfections as well as be a result of interaction between different nanoplatelets in the solution. We also found that the defect photoluminescence may be easily altered by simple mechanical treatment, including sonication and stirring, thus disclosing the ways to control nanoplatelets emission over time.
The size reducing of the focal spot with focusing short pulses using high-performance computer systems
Authors: Savelyev D A , Fomchenkov S A
Published: December 2019

We investigated the change in the type of focal spot when pulsed radiation passed through the diffraction axicon. The Gauss beam and the Gauss-Laguerre mode (1,0) were considered as the input laser radiation with linear polarization. Modelling of diffraction is numerically investigated by the finite difference time domain (FDTD) method. The formation of a shadow focal spot in the immediate vicinity of an optical element and amplification of the longitudinal component of the electric field were shown.
Propagation of short current pulses in Josephson transition line and ultrafast qubit control
Authors: Bastrakova M V , Klenov N V , Ruzhickiy V I , Satanin A M
Published: December 2019

The results of the study of the impact of single-quantum magnetic flux pulses moving along the Josephson transmission lines (JTL) on the dynamics of states of qubits magnetically coupled with such lines are presented. The JTL dynamics was calculated in the frame of resistively shunted junction model with different damping coefficients. This allowed us to find the form of control current pulses (fluxon) acting on a superconducting qubit. Numerical simulations of the simplest logic operations with superconducting qubit due to calculated fluxon impact are presented.
Development of efficient polymer films with upconversion particles
Authors: Lyapin A A , Chernov M V , Kuzmin A M , Gushchin S V , Ermakov A S , Ryabochkina P A
Published: December 2019

In this work, the polymer film based on the upconversion particles doped Er3+ and Yb3+ ions and polyethylene was obtained byusing extrusion and hot pressing methods. Upconversion luminescence spectra of polymer films were recorded in the visible spectral range upon excitation by laser radiation at wavelengths of 972 nm and 1532 nm. The applications of a polymer film in various areas of photonics are discussed.
Nanostructures with magnetooptical and plasmonic response for optical sensors and nanophotonic devices
Authors: Mikhailova T V , Shaposhnikov A N , Tomilin S V , Alentiev D V
Published: December 2019

It was proposed photonic nanostructures with magnetooptical and plasmonic properties that can be effectively used for optical sensors and nanophotonic devices. Optical, magnetooptical and functional properties of photonic crystals with magnetooptical structural elements in the form of films of bismuth-substituted iron garnets and gold plasmonic layer were considered. Simultaneous excitation of optical Tamm states (OTS) and Fabry-Perot resonance or OTS, Fabry-Perot resonance and surface plasmon-polaritons in proposed nanostructures was considered.
The discovered painting decoration of the Vorontsov` Palace in St. Petersburg: Spectroscopic characterization in support of conservation
Authors: Becucci M , Lofrumento C , Parfenov V , Ricci M , Rogozny M , Pakhunov A
Published: December 2019

The paper reports about the unique discovery of fragments of wall painting of the middle of the XVIII century from the Vorontsov` Palace in St. Petersburg and its study by means of laser and IR spectroscopic techniques. The history of creation and reconstruction of the palace as well as technical and technological features of paintings are described.
Efficiency of focusing grating couplers versus taper length and angle
Authors: Kuzin A , Kovalyuk V , Golikov A , Prokhodtsov A , Marakhin A , Ferrari S , Pernice W , Gippius N , Goltsman G
Published: December 2019

Here we experimentally studied dependence of a focusing grating coupler efficiency versus taper length and angle on silicon nitride platform. As a result, we obtained a dependence for the efficiency of a focusing grating coupler on the parameters of the taper length and angle.
Optimization of electrodes for the fast electrochemical actuator
Authors: Shlepakov P S , Uvarov I V , Naumov V V , Melenev A E , Svetovoy V B
Published: December 2019

Electrochemical membrane actuator based on water electrolysis of alternating polarity (AP) was demonstrated recently. It operates several orders of magnitude faster than the devices working on conventional DC electrolysis. However, extremely high current density of the AP process leads to the fast degradation of the electrodes. Titanium electrodes demonstrate the best durability, but they oxidize during operation that reduces the gas production. Proper design can increase the efficiency of the electrodes and slow the degradation down. In this work, four typical layouts are fabricated and tested in the AP electrolysis. Current flowing through the cell, threshold voltage for the explosive operation and wear of the electrodes are analyzed and compared.
Control electrically conductive of thin films by using subminiature eddy current transducers
Authors: Ishkov A , Malikov V
Published: December 2019

The research objective was the development of subminiature eddy-current transducer designed for studying thin films. Timeliness is subject to the need to assess and predict safe operation life of products manufactured using thin films. A review of various methods for thin films studying was made, including the eddy-current method, based on an analysis of the interaction of an external electromagnetic field with the electromagnetic field of eddy currents induced by an energizing winding in an electrically conductive film. A subminiature surface eddy-current transducer of the transformer type was developed. On the basis of eddy-current transducer, a software and hardware complex was developed to control the eddy-current transducer (to generate alternating current of various frequencies, to provide its supply to the eddy-current transducer, to receive a useful signal from transducers to ensure its convenient visualization). The hardware and software complex provided the opportunity to make local studies of the electrical conductivity of non-ferromagnetic thin films by the method of eddy currents. In the course of the study it was possible to develop an algorithm for finding changes in the average amplitude of the output signal, which allows to conclude about the electrical conductivity of the thin film. The study of thin film samples using the developed measuring system is conducted. The results of testing of Al, Ag and Ni films were presented, and the electrical conductivity values of the samples were obtained.
Simulation of transparent electromagnetic interference shielding materials based on periodic conductive networks
Authors: Shiriaev P P , Ryzhenko D S , Makeev M O , Popkov O V
Published: December 2019

This paper is a preliminary report on a theoretical study of transparent shielding materials with potentially very high shielding efficiency based on quasi-periodic conductive networks. An empirical model for rapid calculation of shielding efficiency vs frequency and mesh geometrical parameters is suggested based on numerical simulation results.
Carbon nanotube based terahertz radiation detectors
Authors: Titova N , Gayduchenko I A , Moskotin M V , Fedorov G.F , Goltsman G N
Published: December 2019

In this paper, we study terahertz detectors based on single quasimetallic carbon nanotubes (CNT) with asymmetric contacts and different metal pairs. We demonstrate that, depending on the contact metallization of the device, various detection mechanisms are manifested.
Induction heat treatment of steel punches with Zr-containing coatings and preliminary results of FLD characteristics when drawing C45 carbon steel
Authors: Fomin A , Koshuro V , Shumilin A , Voyko A , Palkanov P , Aman A , Mukhin N , Palis S
Published: December 2019

The paper presents data on strengthening induction heat treatment (IHT) of die tools (punches) and production of wear-resistant Zr-containing coatings on their surfaces. Preliminary results were obtained on the forming limit diagrams (FLD) during drawing (Nakazima’s test) of sheet C45 carbon steel. It was established that punches with Zr-containing coatings after IHT had better characteristics for stretching compared to the uncoated tool steel.
Terahertz response from bio-tissue to silicon nanostructures
Authors: Taranets K B , Fomin M A , Klyachkin L E , Molyarenko A M , Bagraev N T
Published: December 2019

Here we present the first findings on the resonance response of DNA oligonucleotides deposited on silicon nanosandwich (SNS) and living bio-tissue to the THz irradiation that allow their identification by measuring the change of the longitudinal conductance and the lateral voltage within frameworks of the SNS prepared in the Hall geometry. The THz resonance response from living bio-tissue under the THz radiation is also applied to the definition of oncological diseases. The results obtained from the basis of the express diagnostics in practical medicine.
Optimization of the process of obtaining superconducting bilayer films based on niobium nitride and gold for the manufacture of a superconducting single-photon detector
Authors: Davydchenko M
Published: December 2019

We have manufactured a number of bilayer structures based on niobium nitride and gold with different deposition parameters for NbN-Au films (Table 1). We measured the characteristics of superconducting niobium nitride films both with the top layer of gold and without gold. On the basis of the measured characteristics of the films, the optimal parameters of the deposition of NbN-Au bilayer films were chosen for the further formation of a superconducting single-photon detector.
Effect of ion irradiation on resistive switching in metal-oxide memristive nanostructures
Authors: Mikhaylov A N , Belov A I , Korolev D S , Gerasimova S A , Antonov I N , Okulich E V , Shuiskiy R A , Tetelbaum D I
Published: December 2019

The development of artificial intelligence systems is needed to solve many important challenges in neurobiology and neuroengineering for recreation of brain functions and efficient biorobotics. Here we propose a metal-oxide memristive device compatible with CMOS technology and suitable for hardware implementation of neuromorphic tasks. However, metal-oxide memristors have a significant drawback such as variation of resistive switching parameters due to the stochastic nature of filament formation in oxide material. In this work, we control the filament formation process by irradiation of oxide film surface with heavy ions. We have shown that the irradiation of oxide surface in the Au/SiO2/TiN memristive device with Xe+ ions (at energy of 5 keV) decreases the fluctuations of electroforming voltage, current-voltage characteristics during switching and increases the current ratio in the high/low resistance states. The ability to control internal parameters of the memristor can allow more efficiently using memristor as an element of neural networks and other neuromorphic circuits.