bluuebunny/crossref_metadata_2025_split huggingface dataset:
Neuronal‐derived extracellular vesicles are enriched in the brain and serum of HIV‐1 transgenic rats
Authors: Dagur Raghubendra Singh , Liao Ke , Sil Susmita , Niu Fang , Sun Zhiqiang , Lyubchenko Yuri L. , Peeples Eric S. , Hu Guoku , Buch Shilpa 
Published: December 2019

ABSTRACTDespite the efficacy of combination antiretroviral therapy (ART) in controlling human immunodeficiency virus (HIV‐1) replication, cytotoxic viral proteins such as HIV‐1 transactivator of transcription (Tat) persist in tissues such as the brain. Although HIV‐1 does not infect neuronal cells, it is susceptible to viral Tat protein‐mediated toxicity, leading to neuroinflammation that underlies HIV‐associated neurocognitive disorders (HAND). Given the role of extracellular vesicles (EVs) in both cellular homoeostasis and under pathological conditions, we sought to investigate the alterations in the quantity of neuronal‐derived EVs in the brain – as defined by the presence of cell adhesion molecule L1 (L1CAM) and to evaluate the presence of L1CAM+ EVs in the peripheral circulation of HIV‐1 transgenic (HIV‐1 Tg) rats. The primary goal of this study was to investigate the effect of long‐term exposure of HIV‐1 viral proteins on the release of neuronal EVs in the brain and their transfer in the systemic compartment. Brain and serum EVs were isolated from both wild type and HIV‐1 Tg rats using differential ultracentrifugation with further purification using the Optiprep gradient method. The subpopulation of neuronal EVs was further enriched using immunoprecipitation. The current findings demonstrated increased presence of L1CAM+ neuronal‐derived EVs both in the brain and serum of HIV‐1 Tg rats.
Thermal generation of shift electric current
Authors: Budkin G V , Tarasenko S A 
Published: December 2019

Abstract
It is shown that the dissipation of energy in an electron gas confined in a quantum well made of non-centrosymmetric crystal leads to a direct electric current. The current originates from the real-space shift of the wave packets of Bloch electrons at the electron scattering by phonons, which tends to restore thermal equilibrium between the electron and phonon subsystems. We develop a microscopic theory of such a phonogalvanic effect for narrow band gap zinc-blende quantum wells.
Implications of pinned occupation numbers for natural orbital expansions: I. Generalizing the concept of active spaces
Authors: Schilling Christian , Benavides-Riveros Carlos L , Lopes Alexandre , Maciążek Tomasz , Sawicki Adam 
Published: December 2019

Abstract
The concept of active spaces simplifies the description of interacting quantum many-body systems by restricting to a neighborhood of active orbitals around the Fermi level. The respective wavefunction ansatzes which involve all possible electron configurations of active orbitals can be characterized by the saturation of a certain number of Pauli constraints

0
≤

n

i

≤
1

, identifying the occupied core orbitals (n

i
= 1) and the inactive virtual orbitals (n

j
= 0). In Part I, we generalize this crucial concept of active spaces by referring to the generalized Pauli constraints. To be more specific, we explain and illustrate that the saturation of any such constraint on fermionic occupation numbers characterizes a distinctive set of active electron configurations. A converse form of this selection rule establishes the basis for corresponding multiconfigurational wavefunction ansatzes. In Part II, we provide rigorous derivations of those findings. Moroever, we extend our results to non-fermionic multipartite quantum systems, revealing that extremal single-body information has always strong implications for the multipartite quantum state. In that sense, our work also confirms that pinned quantum systems define new physical entities and the presence of pinnings reflect the existence of (possibly hidden) ground state symmetries.
Implications of pinned occupation numbers for natural orbital expansions. II: rigorous derivation and extension to non-fermionic systems
Authors: Maciążek Tomasz , Sawicki Adam , Gross David , Lopes Alexandre , Schilling Christian 
Published: December 2019

Abstract
We have explained and comprehensively illustrated in Part I (Schilling et al 2019 arXiv:1908.10938) that the generalized Pauli constraints suggest a natural extension of the concept of active spaces. In the present Part I (Schilling et al 2019 arXiv:1908.10938)I, we provide rigorous derivations of the theorems involved therein. This will offer in particular deeper insights into the underlying mathematical structure and will explain why the saturation of generalized Pauli constraints implies a specific simplified structure of the corresponding many-fermion quantum state. Moreover, we extend the results of Part I (Schilling et al 2019 arXiv:1908.10938) to non-fermionic multipartite quantum systems, revealing that extremal single-body information has always strong implications for the multipartite quantum state. In that sense, our work also confirms that pinned quantum systems define new physical entities and the presence of pinnings reflect the existence of (possibly hidden) ground state symmetries.
Investigating interaction of microdischarges with TiO2 surface films in the cell of dielectric barrier discharge
Authors: Andreev V V 
Published: December 2019

Abstract
The paper presents the results of studying the interaction of microdischarges in the cell of dielectric barrier discharge (DBD) with enamel-based surface films deposited on a fabric-based laminate. TiO2 powder was added to the surface films. Elemental composition of the surface films was studied in the areas with different level of microdischarges exposure. Before measurement, the samples were bonded onto a 25 mm aluminum specimen with conductive silver paint. The metal was coated with a thin film (13 nm) of carbon using magnetron sputtering method. The observations were carried out using Hitachi SU8000 field-emission scanning electron microscope (FE-SEM). Images were acquired in secondary electron mode at 30 kV accelerating voltage and at working distance 8-15 mm. EDX-SEM investigation and mapping were carried out using Oxford Instruments X-max EDX system. Before measurement, the samples were coated with a thin film (13 nm) of carbon using Cressington 208 carbon coater. The study results showed significant effect of microdischarges in the DBD cell on elemental composition of surface films deposited on the fabric-based laminate surface.
Online course (MOOC) “Concepts of Modern Natural Science” on the National Platform of Open Education: experience in teaching students
Authors: Babaeva M A 
Published: December 2019

Abstract
The article discusses transformation of the education system under the influence of MOOC. It provides information about the features of open online courses offered on the Russian national platform for open education (NPOE), and their place in the educational process of Russian universities. We show the structure of the MOOC “Concepts of Modern Natural Science” at NPOE and consider the features of using the MOOC in teaching natural sciences to humanities students of the Polytechnic University (in blended learning format as well as in completely online learning). The authors investigate the efficiency of the electronic format in teaching students a non-major discipline. We present and discuss the results of the statistical processing of data obtained when testing and surveying the online course students. The article shows the efficiency of applying the MOOC in the implementation of the university’s educational programs.
To the possibility of using clocks in gravitational antenna network
Authors: Izmailov G N 
Published: December 2019

Abstract
When gravitational waves (GW) spread in space-time, we usually say that spatial distances between reference points are distorted. The LISA project was developed to measure distortion in space. Simultaneously with the GW arrival, time intervals are also distorted. For this purpose, the pulsar timing method was developed. This article proposes to use a network of stabilized atomic clocks installed on deep-space spacecraft to measure time interval. A preliminary estimate of the required accuracy of clocks when registering GW is offered. It is indicated that a network of clocks installed on LISA-type spacecraft can serve as an additional and independent GW detection channel.
Temperature features of ZnO exciton luminescence
Authors: Kokin S M , Nikitenko V A , Pautkina A V , Stoyukhin S G 
Published: December 2019

Abstract
The study shows exciton-phonon luminescence (EPL) of free excitons in ZnO crystals within temperatures 77-300 K. It’s been found that low resistivity samples with temperatures above 150 K demonstrate temperature anomalies in the EPL of free excitons, which is supposed to be the result of the exciton – electron interaction. The EPL temperature dynamics is closely related to the nature of a defective crystal structure. This allows that we should propose a method of quality non-destructive operation with zinc oxide crystals. The paper describes conditions for recording the specific luminescence spectrum of ZnO, which can be the result of inelastic scattering of free excitons and which is accompanied by radiation of excited excitons and exciton-phonon complexes.
Baric and dimensional changes of niobium properties
Authors: Kramynin S P , Akhmedov E N 
Published: December 2019

Abstract
We have calculated the baric dependencies of thermophysical properties and melting temperature as well as the thermal equation of state for niobium based on the pair interatomic Mi-Lenard-Jones potential and the crystal Einstein model for niobium (Nb). Baric dependencies computations made along two isotherms 300 K and 3000 K are in good agreement with the experimental data for niobium. We have obtained the charts of pressure dependencies for the following properties: Debye temperature, the first, second and third Gruneisen parameters, isothermal compression modulus, isochoric and isobaric heat capacity, volumetric coefficient of thermal expansion and the melting temperature. The article investigates size dependencies of both specified properties and the melting temperature of niobium using an RP-model of nanocrystal.
An approximate model for slow free-surface flows of a fluid through a highly porous medium accounting for the effect of a capillary fringe
Authors: Leontiev N E , Roschin E I 
Published: December 2019

Abstract
The paper proposes a model for unconfined creeping flows of a thin fluid layer through a highly porous medium accounting for the effect of a capillary fringe at the free surface. To derive the model, we used the thin-layer approximation for the Brinkman equation with the Navier slip conditions at both the impermeable underlying surface and the free surface. The equation for the fluid layer thickness appears to be a special type of the non-linear heat conduction equation. We present similarity solutions that describe fluid propagation over a horizontal substrate.
Investigating dynamics of the interface between air and magnetic fluid in the so-called magnetic vacuum within an annular magnet
Authors: Polunin V M , Ryapolov P A , Sokolov E A , Moroz V S 
Published: December 2019

Abstract
Magnetic, acoustic, and thermophysical phenomena in magnetic fluid systems have found application in the design of magnetic fluid seals, shock absorbers, sensitive three-axis accelerometers, density meters, and a number of other advanced devices. This explains the interest in studying these effects. Lately, due to the rapid development of microfluidics, more and more works have appeared that deal with magnetic fluid dynamics in channels of various shapes when various external physical fields affect them. However, several aspects have only been studied superficially, although they are potentially of great scientific and practical interest; these are levitating gas cavity properties and magnetic, acoustic and thermophysical phenomena accompanying dynamic gas cavity and bubble displacement in a magnetic fluid. This paper investigates the dynamics of bubble trapping in magnetic fluid located in the so-called magnetic vacuum region of an annular magnet. We obtained data on effects of centrifugation and magnetic fluid structure on the strength of magnetic fluid bridges subjected to external pressure. This information may be useful for developing a test bench for magnetic fluids used in seals, where fluids undergo similar effects. We used two samples of magnetic fluid to perform an experiment which involved compressing the air cavity, eventually leading to gas bubbles detaching from the samples. We draw conclusions concerning the effects of physical parameters of magnetic fluids and magnetic field configuration on the diameter of the resulting bubbles.
Study of efficiency of using vibration to improve the process of loose raw material classification
Authors: Kharitonov A , Busigina E , Maslennikov I 
Published: December 2019

Abstract
The paper presents the results of a study dedicated to assessment of the effectiveness of vibration use to intensify the process of classification of loose mediums at arch screens. In the laboratory, the experiment was based on the separation of bulk material flow at the arch screen. The frequency and amplitude of oscillations of the screening surface were taken as variable parameters, while the response function was the fraction of take-off product in the total volume of the sifted mass of bulk material. According to the experiment data processing using the method of mathematical planning, the feasibility of vibrations application was confirmed, providing a reduction of energy consumption up to 14%.
Use of graphic computer programs in the study of engineering graphics
Authors: Kharitonov A , Nikitina O 
Published: December 2019

Abstract
The paper is devoted to study of processes occurring in a higher school, in the field of graduates’ graphics studies. We consider the necessity of graphical package knowledge and achieving confident user skills for computer programs. We make an attempt to tackle a debatable problem on students acquiring computer-aided drafting skills. The increase of necessity for graphics packages study by the students of all specialties is justified. The paper demonstrates the findings of comparative analysis of different methods of teaching graphics in a higher school. The influence and possibilities of technologies in education was examined through theoretical material in lecture course and practical studies.
Raman spectroscopy of silicon nanowires formed by metal-assisted chemical etching
Authors: Yakunin V G , Asilbaeva R B , Rodichkina S P , Alykova A F , Turmukhambetov A Zh , Timoshenko V Yu 
Published: December 2019

Abstract
Silicon nanowires obtained by metal-assisted chemical etching of crystalline silicon (Si) wafers are studied by Raman spectroscopy to reveal the effect of the formation time of nanowires and their additional doping with boron and phosphorus. The observed modification of the spectrum shape in the boron-doped samples due to the Fano effect made it possible to estimate the concentration of free holes in Si nanowires, which is of the order of 1019 - 1020 cm3, depending on the preparation conditions. The obtained results indicate the potential of the Raman spectroscopy for contactless diagnostics of Si nanostructures.
Study of the luminescence from polymeric membrane swollen in water with various content of deuterium; isotopic effects
Authors: Bunkin N F , Bashkina U A , Bolikov N G , Bereza I S , Molchanov I I , Kozlov V A 
Published: December 2019

Abstract
The paper describes the experiments with the irradiation in the near UV range of a swollen surface of Nafion polymer membrane in the grazing-incidence pumping geometry. The pump radiation caused a photoluminescence from the Nafion interface in a certain spectral range. The photoluminescence signal proved to be an important parameter for describing the swelling of the polymer in water. It is shown that luminescence is generated due to the presence of sulfonic groups, anchored to the ends of the perfluorovinyl ether groups forming a tetrafluoroethylene (Teflon) base. The dynamics of Nafion swelling was studied depending on the content of deuterium in water. In the case where the polymer is swollen in water with different deuterium content, isotopic effects appeared to be largely manifested.
Optical properties of globular photonic crystals with different particle sizes
Authors: Gorelik V S , Bi Dongxue , Yurasova I I 
Published: December 2019

Abstract
The article reports the results of experimental studies of the optical properties of globular photonic crystals filled with various chemical liquids. It opens up the possibility of creating highly sensitive refractive sensors of chemical compounds based on the introduction of these substances into the pores of opal matrices. The optical properties of opal matrices with different sizes of globules have been analyzed. Different spectral positions of the stop bands are present in the reflectance spectrum of globular photonic crystals, depending on the size of the particles. The sharp increase in the density of photonic states in photonic crystals opens up the possibility of increasing the efficiency of Raman scattering and nonlinear-optical processes in materials of this kind.
Dynamic type Fourier spectrometer development for Raman spectra detection
Authors: Balashov A A , Golyak Ig S , Golyak Il S , Morozov A N , Khorokhorin A I 
Published: December 2019

Abstract
The dynamic Fourier spectrometer model for Raman scattering (RS) is developed. The working spectral range is 800–1050 nm. The excitation source is the laser with the wavelength λ = 785 nm. In the spectrometer the “white light” channel for summing interferograms over several scans is implemented. Also the reference channel with a sampling frequency of λ / 4 is realised. The developed layout in experiments of the chemical compounds registration is approved. The signal-to-noise ratios for recorded Raman spectra are also calculated. The work shows the RS spectra of stilbene (C14H12) and 1,4-bis (5-phenyl-2-oxazolyl) benzene (POPOP, C24H16N2O2) recorded on the model spectrometer. An experimental research of the registration of the minimum amount of stilbene (C14H12) dissolved in acetone using the Raman spectroscopy method was carried out.
Movable mirror of Michelson interferometer in Fourier’s spectrometer steadiness assessment
Authors: Demkin P P 
Published: December 2019

Abstract
A method to assess steadiness of movable mirror of Michelson interferometer in Fourier’s spectrometer has been developed. Steadiness of movable mirror motion has been analyzed experimentally using three devices with different control systems of the movable mirror. A comparative analysis of the speed steadiness of the frame motion has been made, using analog and digital control types, with and without feedback. We have found that the developed method helps to analyze the above mentioned process faster if there is an interference pattern. We have shown that the control system without feedback has more deviation of speed motion than one with feedback.
Generation and detection of high-frequency gravitational waves in dielectrics, excited by the intense ultrashort laser pulse
Authors: Gorelik V S 
Published: December 2019

Abstract
The generation and detection of scalar or pseudoscalar high-frequency gravitational waves in some dielectrics, excited by ultrashort intense laser pulses are proposed. Hidden photons and axion particles are elemental excitations of such gravitational waves. The properties of longitudinal electromagnetic waves in dielectric media have been described from the point of view of photon-hidden photon conversion processes in these crystals. Scalar bound photonic states in dielectric media are analyzed. The experimental schemes for photon-hidden photon conversion with taking part in longitudinal electromagnetic excitations in media have been proposed. Hertz gravitational laboratory experiments with the illumination of the dielectric media by intense ultrashort laser pulses and the “Light Sching Trough Wall” scheme using are analyzed.
Directed UV and X-ray generation in nanomaterials at the optical excitation
Authors: Tcherniega N V , Baranov A N , Belyanin A F , Borisov V V , Karpov M A , Kudryavtseva A D , Kuznetsova M V , Rozinskii D V , Shevchenko M A 
Published: December 2019

Abstract
Efficient electromagnetic emission of radiation in the spectral range with wavelengths shorter than exciting light wavelength was observed at the nanomaterials excitation by laser pulses. Emission was registered in a visible (blue-green) range, in vacuum UV and in soft X-ray. Luminescence was registered both in the air and in the vacuum chamber. Synthetic opal matrices and nanocomposites on their base (matrices infiltrated with different liquids) were used as samples. Luminescence was excited with the help of different lasers: ruby laser, second harmonic of Nd:YAG laser and copper vapor laser. In the visible range two regimes of luminescence were observed: fast (few μs) and slow (up to 12 s). Slow luminescence was registered at temperatures lower than 110 K. Spectra of X-ray emission were registered. The connection of this emission with the triboluminescence effect is considered.
Optical characteristics of the aluminium mesoporous photonic crystal
Authors: Gorelik V S , Pichkurenko S V , Filatov V V 
Published: December 2019

Abstract
We propose the novel, Kurosawa-like, easy-to-use method to calculate the optical properties of the periodical photonic structures. We start from the experimental transmittance data for the aluminium-oxide-based mesoporous photonic crystal film, and simulate its reflectance, dispersion law and the group velocity of light propagated in the film. We established the anomalous speed-of-light deceleration at the photonic bandgaps edges. The good theory-to-experiment agreement allows to use our technique for the various photonic applications
Raman opalescence near the phase transition point in lead germanate crystals
Authors: Pyatyshev A Y , Gorelik V S 
Published: December 2019

Abstract
It was established that the nature of opalescence near the phase transition point in a lead germanate crystal is dynamic and is caused by a sharp increase in the spectral intensity of Raman scattering on a soft mode responsible for the instability of the crystal lattice near the phase transition temperature. Experimental studies of combination opalescence in a soft mode were performed using the method of constructing isofrequency temperature dependences of the spectral intensity for fixed values of the frequency shift Ω of the scattered radiation relative to the frequency ω0 of the exciting radiation. It is shown that the experimentally observed anomalies of the spectral intensity agree with the dynamic theory of phase transitions in crystals, based on the concept of softening of the crystal lattice in the phase transition region.
Software for numerical simulation of the combustion of aluminum particles suspended in air
Authors: Romanova T N , Yagodnikov D A , Shchetinin G A 
Published: December 2019

Abstract
This paper presents a computer model for studying the processes of ignition and combustion of air suspended aluminum particles, based on a system of differential equations of the gas phase balance and the probability density function for temperature and particle size. The model is implemented as software for a two-dimensional non-steady state case. A new implicit difference scheme consisting in two - and three-point approximations for the first and second derivatives is proposed and implemented. A set of calculations is performed and the results of the reacting mixture characteristics distribution, the areas of the maximum heat release and their relationship with the most air suspension probable state are presented.