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Specificity of electrophysical and gas-sensitive properties of nanocomposite ZnO–TiO_(2) films formed by solid-phase pyrolysis

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ChemPhysMater 2024年第3期3卷 314-319页

作者： victor v.petrov Maria G.volkova Alexsandra P.Ivanishcheva Gleb v.Tolstyak Ekaterina M.Bayanb Institute of Nanotechnologies Electronicsand Equipment EngineeringSouthern Federal UniversityTaganrog 347922Russia Faculty of Chemistry Southern Federal UniversityRostov-on-Don 344090Russia

ZnO–TiO_(2) thin films containing 0.5 mol%,1.0 mol%,and 5.0 mol%ZnO were synthesized by oxidative solidphase *** materials contained anatase and rutile phases with particle size of 6–13 nm,as confirmed using X-ray phase analysis and scanning electron *** a certain number of ZnO crystallites appeared in the TiO_(2) film structure in the temperature range of room temperature to 220℃,a two-level response of the film resistance was observed,differing by approximately 10%,as obtained by electrophysical *** two-level response correlates with the formation of two donor energy levels of 0.28 and 0.33 ev in the band structure of the ZnO–TiO_(2) *** donor level with a higher activation energy corresponded to the Ti vacancy(v−Ti),and that with a lower activation energy corresponded to the Zn vacancy(v−Zn).Two levels of gas-sensitive properties were noted for 0.5ZnO–TiO_(2),1ZnO–TiO_(2),and 5ZnO–TiO_(2) under the influence of 50 ppm NO_(2) at 250℃.Such two-level responses can be ascribed to the pinning of the Fermi level on ZnO and TiO_(2) *** mechanism of the beak-shaped and two-level responses of sensors based on composite nanomaterials when exposed to various gases was elucidated.

关键词： Thin film ZnO TiO_(2) Nanocomposites Pyrolysis Gas sensors

Investigation of WZ Sge-type Dwarf Nova ASASSN-19oc:Optical Spectroscopy and Multicolor Light Curve Analysis

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Research in Astronomy and Astrophysics 2024年第8期24卷 20-31页

作者： viktoriia Krushevska Sergey Shugarov Paolo Ochner Yuliana Kuznyetsova Mykola petrov Peter Kroll Astronomical Institute of the Slovak Academy of Sciences Tatranska Lomnica05960 VysokéTatrySlovakia Main Astronomical Observatory of NAS of Ukraine 27 Akademika Zabolotnoho St.03143 KyivUkraine INAF—Osservatorio Astronomico di Padova Vicolo dell’Osservatorio 5I-35122 PadovaItaly Department of Physics and Astronomy University of PadovaVia F.Marzolo 8I-35131 PadovaItaly Max Planck Computing and Data Facility(MPCDF) Gießenbachstrasse 2D-85748 GarchingGermany Sonneberg Observatory Sternwartestr.32D-96515 SonnebergGermany

In this study,we present an investigation of the newly discovered dwarf nova ASASSN-19oc during its superoutburst on 2019 June *** carried out detailed UBvRcIc-photometric observations and also obtained a spectrum on day 7 of the outburst,which shows the presence of hydrogen absorption lines commonly found in dwarf nova *** of photometric data reveals the occurrence of early superhumps in the initial days of observations,followed by ordinary and late *** have accurately calculated the period of the ordinary superhumps as Pord=0.05681(10)days and determined the periods at different stages,as well as the rate of change of the superhump period(P_(dot)=(5)P/P=8.1×10^(-5)).Additionally,we have derived the mass ratio of the components(q=0.09),and estimated the color temperature during the outburst as~11,000 K,the distance to the system(d=560 pc)and absolute magnitude of the system in outburst(Mv=5.3).We have shown that outbursts of this star are very rare:based on brightness measurements on 600 archival photographic plates,we found only one outburst that occurred in *** fact,as well as the properties listed above,convincingly shows that the variable ASASSN-19oc is a dwarf nova of WZ Sge type.

关键词： (stars)binaries(including multiple) close-(stars)novae-cataclysmic variables-stars dwarf novae

Investigation of electrophysical, photo- and gas-sensitive properties of ZnO–SnO_(2) sol–gel fflms

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Journal of Advanced Dielectrics 2024年第1期14卷 42-50页

作者： Irina A.Gulyaeva Alexandra P.Ivanisheva Maria G.volkova victoria Yu.Storozhenko Soslan A.Khubezhov Ekaterina M.Bayan victor v.petrov Research and Education Centre“Microsystem Technics and Multisensory Monitoring Systems”Southern Federal University Russia Department of Chemistry Southern Federal UniversityRussia Department of Physics North-Ossetian State University362025 VladikavkazRussia Department of Physics and Engineering ITMO University191002 PetersburgRussia

Thin nanocomposite fflms based on tin dioxide with a low content of zinc oxide(0.5–5 mol.%)were obtained by the sol–gel *** synthesized fflms are 300–600 nm thick and contains pore sizes of 19–29 *** resulting ZnO–SnO_(2) fflms were comprehensively studied by atomic force and Kelvin probe force microscopy,X-ray diffraction,scanning electron microscopy,and high-resolution X-ray photoelectron spectroscopy *** photoconductivity parameters on exposure to light with a wavelength of 470 nm were also *** study of the photosensitivity kinetics of ZnO–SnO_(2) fflms showed that the fflm with the Zn:Sn ratio equal to 0.5:99.5 has the minimum value of the charge carrier generation time *** of the activation energy of the conductivity,potential barrier,and surface potential of ZnO–SnO_(2) fflms showed that these parameters have maxima at ZnO concentrations of 0.5 mol.%and 1 mol.%.Films with 1 mol.%ZnO exhibit high response values when exposed to 5–50 ppm of nitrogen dioxide at operating temperatures of 200℃ and 250℃.

关键词： Sol–gel method,ZnO–SnO_(2) films gas-sensitive properties surface potential potential barrier conduction activation energy

Ambiguity of Polystyrene Aerosol Beads Properties Found with Mie Spectra Analysis

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光谱学与光谱分析 2020年第1期40卷 324-327页

作者： petrov D v Zhuzhulina E A Crimean Astrophysical Observatory(CrAO RAS)

Broadband Mie scattering is used to determine the parameters of polystyrene aerosol beads in air,such as size and wavelength dependence of refractive *** method consists in the selection of such parameters of the scattering object,which reproduce observed spectrum *** is why it is very sensitive and hence very *** found that there is an ambiguity of polystyrene aerosol beads properties,determined with this *** combinations of polystyrene particle size and its refractive index can give the same position of Mie *** ambiguity leads to an increase in the error in determining the size and refractive index of the *** refined errors are calculated and the way of their reduction is indicated.

关键词： Nanomaterials Mie theory Polystyrene beads Size Refractive index

Spectral Dependence of Quasi-Rayleigh Polarization Leap of Nonspherical Particles:Polystyrene Beads Application

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光谱学与光谱分析 2021年第2期41卷 654-657页

作者： petrov D v Zhuzhulina E A Crimean Astrophysical Observatory(CrAO RAS) 298409 Nauch nyjRussia

Solid particles in Earth’s atmosphere,such as polystyrene beads,are an important factor affecting the processes of absorption and scattering of light in the *** processes affect on the solar energy transfer in the Earth’s atmosphere,consequently they have influence on the regional and global climate changes and atmospheric *** particular,great interest to study the scattering properties of small particles compared with wavelength,because of such particles experience low gravitational settlement and may have long time of life in the *** scattering particle is much smaller than the wavelength of the scattered or absorbed light,this is the case of Rayleigh *** properties of these particles(such as intensity and the degree of linear polarization)at the Rayleigh scattering are simply derived from electromagnetic Maxwell’s *** when the particles are large enough to be comparable with the wavelength,the deviations from Rayleigh scattering law are *** of the clear manifestations of such deviations is the recently discovered quasi-Rayleigh polarization leap of monodisperse spherical *** quasi-Rayleigh polarization leap allows remote sensing of the sizes of distant particles,based on the spectral position of quasi-Rayleigh polarization leap at different phase angles of *** this paper,we studied the effect of the non-sphericity of a scattering polystyrene particle on the magnitude and position of the quasi-Rayleigh polarization *** is established that the non-sphericity shifts the position of the quasi-Rayleigh polarization leap shorter *** is shown that for non-sphericity of particles makes the quasi-Rayleigh polarization leap becomes less ***,it was found,that increasing of the phase angle and degree of non-sphericity shift the quasi-Rayleigh polarization leap position to shorter ***,in the case of not very elongated particles,the quasi-

关键词： Nanomaterials Polarization T-matrix Quasi-Rayleigh polarization leap

Incubation time approach in rock fracture dynamics

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Science China(Physics,Mechanics & Astronomy) 2012年第1期55卷 78-85页

作者： SMIRNOv v petrov Yuri v BRATOv v St.-Petersburg State Transport University 198103 St.-Petersburg Russia St.-Petersburg State University 198504 St.-Petersburg Russia Institute of Problems of Mechanical Engineering Russian Academy of Sciences 199178 St.-Petersburg Russia

The paper is summarizing latest results connected with application of the incubation time approach to problems of dynamic fracture of rock materials. Incubation time based fracture criteria for intact media and media with cracks are discussed. Available experimental data on high rate fracture of different rock materials and incubation time based fracture criteria are used in order to evaluate critical parameters of causing fracture in these materials. Previously discovered possibility to optimize (minimize) energy input for fracture is discussed in connection to industrial rock fracture processes. It is shown that optimal value of momentum associated with critical load in order to initialize fracture in rock media does strongly depend on the incubation time and the impact duration. Existence of optimal load shapes minimizing momentum for a single fracturing impact or a sequence of periodic fracturing impacts is demonstrated.

关键词： incubation time dynamic fracture rocks dynamic strength fracture toughness crack resistance energy and momentum input fracture process optimization

SIMULATION MODEL OF TECHNOLOGICAL MINERAL DRESSING PROCESSES

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International Journal of Modeling, Simulation, and Scientific Computing 2012年第3期3卷 36-42页

作者： NGUYEN vAN CHI A.v.petrov Department of Automated Systems Irkutsk State Technical University Lermontova 83 Irkutsk664074Russian Federation

The authors worked out a simulation model of technological mineral dressing processes,in which two simulations of technological mineral dressing processes methods are used:transformed structural graph method and method of separation *** first method makes it possible to simulate technological mineral dressing processes at the design stage in conditions of feedstock,equipment and control information *** second method is an effective instrument for operating plant simulation at the reengineering *** and economic efficiency evaluations of the mineral dressing plant are appended to the model.

关键词： Simulation mineral dressing structural graph separation characteristics reengineering efficiency

Magnetic and XPS studies of lithium lanthanide tetraphosphates LiLnP_4O_(12)(Ln=Nd,Gd,Er)

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Journal of Rare Earths 2013年第5期31卷 485-489页

作者： D.petrov B.Angelov v.Lovchinov Department of Physical Chemistry Plovdiv University"Paisii Hilendarski" 24 Tsar Asen Str. 4000 Plovdiv Bulgaria Department of Inorganic and Physical Chemistry University of Food Technologies-Plovdiv26 Maritsa Blvd. 4002 Plovdiv Bulgaria Institute of Solid State Physics Bulgarian Academy of Sciences72Tsarigradsko Chaussee Blvd.1784 SofiaBulgaria

Magnetic susceptibilities of flux-grown single crystals of LitnP4012 （Ln=Nd, Gd, Er） were measured in the temperature range of 2-300 K. The compounds were paramagnetic, and obeyed the Curie-Weiss law in the entire temperature interval, without magnetic phase transitions, and with effective magnetic moments close to those of the corresponding free Ln3＋ ions. X-ray photoelec- tron spectroscopy was applied to determine the positions of core-level electrons relative to the Fermi level： Li is; Ln 4f, 5p, 5s, 4d, 3d; P 2s, 2p; O 1s, 2s. The binding energies in these compounds were found slightly shifted compared to the respective values of the same elements.

关键词： lithium lanthanide tetraphosphates single crystals magnetic properties XPS spectroscopy rare earths

Energy of a solid sphere under nonstationary oscillations

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Science China(Physics,Mechanics & Astronomy) 2014年第3期57卷 469-476页

作者： petrov Yu. SMIRNOv v. UTKIN A. BRATOv v. St.-Petersburg State University Institute of Problems of Mechanical Engineering Russian Academy of Sciences St.-Petersburg State Transport University

Analytical solution for spherically symmetric nonstationary oscillations of acoustic and elastic solid sphere is *** dependence of potential,kinetic and internal energy of a solid sphere is *** received results are of practical importance for a wide range of problems connected to testing of material dynamic strength parameters and to the problems of optimizing(minimizing)energy needed for fracture of solids.

关键词： nonstationary oscillations analytical solution material dynamics dynamic elastisity kinetic energy potential energy internal energy energy exchange