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Management of Control Impacts Based on Maximizing the Spread of Influence

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International Journal of Automation and computing 2019年第3期16卷 341-353页

作者： Alexander Tselykh Vladislav Vasilev Larisa Tselykh Institute of Computer Technologies and Information Safety Southern Federal University.Rostov-on-Don 344006.Russia Department of Economics and Business Rostov State University of EconomicsRostov-on-Don 344002.Russia

The choice of fulcrums for control of socio-economic systems represented by direc ted weighted signed graphs is a topic of current *** article proposes a new method for identifying nodes of impact and influential nodes,which will provide a guaranteed positive system response over the growth *** task is posed as an optimization problem to maximize the ratio of the norms of the accumulated increments of the growth vector and the exogenous impact *** algorithm is reduced to solving a quadratic programming problem with nonlinear *** selection of the most effective vertices is based on the cumulative gains of the component projections onto the solution *** examples arc provided to illustrate the effectiveness of the proposed method.

关键词： Directed weighted graphs control impact spread of influence optimization algorithm growth model

Ferroelectric solid solutions with perovskite- and columbite-type components: From structures formation to domain and hysteresis phenomena

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Journal of Advanced Dielectrics 2023年第2期13卷 13-23页

作者： M.O.Moysa V.Yu.Topolov K.P.Andryushin A.V.Nagaenko L.A.Shilkina M.V.Il’ina O.I.Soboleva S.Sahoo L.A.Reznichenko Research Institute of Physics Southern Federal University194 Stachki Avenue Rostov-on-Don 344090Russia Department of Physics Southern Federal University5 Zorge Street Rostov-on-Don 344090Russia Institute of High Technologies and Piezotechnics Southern Federal University 10 Milchakov StreetRostov-on-Don 344090Russia Institute of Nanotechnologies Electronics and Equipment Engineering Southern Federal UniversityTaganrog 347922Russia Research Laboratory of Functional Nanomaterials Technology Southern Federal university Taganrog 347922Russia

The paper reports results on the complex study on ferroelectric ceramics that represent solid solutions containing components with a perovskite-type or columbite-type *** solutions of a three-component(1−x−y)NaNbO_(3)−xKNbO_(3)−yCdNb_(2)O_(6) system are manufactured at x=0.05-0.20 and y=*** structures in ceramic grains are *** consistency between experimental and calculated results is examined for coexisting phases split into non-180°domains(mechanical twins)in the solid solution with x=0.15.A correlation between the internal structure(crystal,domain,granular,and defect)and fundamental electromechanical and polarization properties is stated for the studied three-component solid solutions.

关键词： Ferroelectric materials KNN elastic matching crystal structure domain structure electrophysical properties.

Studying of dielectric spectra of YCu_(0.15)Mn_(0.85)O_(3)solid solution with the use of complex conductivity

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Journal of Advanced Dielectrics 2022年第1期12卷 19-23页

作者： A.V.Nazarenko A.V.Pavlenko Y.I.Yurasov Federal Research Centre The Southern Scientific Centre of the Russian Academy of Sciences(SSC RAS) 41 Chekhova Street Rostov-on-Don 344006Russia Research Institute of Physics Southern Federal university 105/42 Bolshaya Sadovaya Street rostov-on-don 344006 Russia

This work presents the results of studying the electrophysical properties of the YCu_(0.15)Mn_(0.85)O_(3)solid solution in the range of temperatures of T=26-400°C and frequency range of f=102-105 Hz.A model description of the revealed dispersion of dielectric parameters in the material is *** nonclassical modified Havriliak-Negami model written for complex electrical conduc-tivity was used as an approximation *** is shown that the application of this model almost exactly describes the frequency behavior of the dielectric constantε′/ε0(f),the dielectric loss tangent tgδ(f)as well as the real and imaginary parts of complex conductivityγ′(f)andγ′′(f).The results of this work are an important step in identifying the opportunities and understanding the applications of this model.

关键词： Multiferroics yttrium manganite relaxation Havriliak-Negami model complex conductivity

Microstructure features of the BST/(Mg,Ln)-ceramic

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Journal of Advanced Dielectrics 2022年第2期12卷 19-24页

作者： K.P.Andryushin A.V.Nagaenko S.V.Khasbulatov L.A.Shilkina E.V.Glazunova S.I.Dudkina I.N.Andryushina L.A.Reznichenko Research Institute of Physics Southern Federal University 194 Stachki Str.Rostov-on-Don 344090Russia Institute of High Technology and Piezo Technic Southern Federal University 10 MilchakovaRostov-on-Don 344090Russia Faculty of Physics and Information-Communication Technologies 32 Sheripova Str. Grozny 364024Russia

Solid solutions of the composition Ba_(1-x-y)(Mg,Ln)_(x)SryTiO_(3)(x=0.01;0.025;0.04;y=0.20;0.50;0.80;Ln=La,Pr,Nd,Sm,Eu,Gd,Tb,Dy,Ho,Er,Tu,Yb)were prepared by two-stage solid-phase synthesis followed by sintering using conventional ceramic *** influence of rare-earth elements on the microstructure of the prepared ceramic samples was *** was found that regardless of the type of modifiers introduced,the grain landscape of the studied solid solutions with different amounts of SrTiO_(3)is refined(in the initial system,the average grain size,d,at x=0.20 is 6μm;at x=0.50 is 4μm;at x=0.80 is 18μm)to crystallite sizes not exceeding(2-3)μm,and *** using of mechanical activation procedures leads to an even greater decrease in the size and an increase in the density of *** increasing in the concentration of modifiers in each group(within the considered range of dopant variation)against the background of such a fine-grained structure has little effect on the dynamics of changes in *** is concluded that it is advisable to use the data obtained in the development of functional materials based on BST/(Mg,Ln)and devices with the participation of these compositions.

关键词： Ceramics BST microstructure rare-earth elements

Colossal dielectric response and complex impedance analysis of LaFeO_(3)ceramics

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Journal of Advanced Dielectrics 2022年第5期12卷 60-66页

作者： Sushrisangita Sahoo K.P.Andryushin P.K.Mahapatra R.N.P.Choudhary Research Institute of Physics Southern Federal University 344090Rostov-on-DonRussia Department of Physics Siksha O Anusandhan(Deemed to be University)BhubaneswarIndia

The present investigations mainly focused on the colossal dielectric response and complex impedance analysis of LaFeO3 *** studied sample was prepared by a citrate gel *** and microstructural properties are analyzed from the XRD pattern and SEM *** anomalies in the dielectric constant versus temperature plots are analyzed on the basis of polarization induced by the Maxwell-Wagner mechanisms and ferromagnetic interaction between the Fe3+ions driven by the oxygen vacancy mediated Fe^(3+)-Vo-Fe3+exchange interaction A giant dielectric permittivity in the order of~105 was observed in the sample even at the room temperature for 100 *** colossal dielectric constant in LaFeO3 is mainly driven by the internal barrier layer capacitor(IBLC)*** formation of IBLC was explained on the basis of highly insulating grain boundary and less resistive/semiconducting grain,which was confirmed from both the resistance and capacitance of grain and grain boundary from the impedance *** non-Debye-type relaxation process associated with the grain and grain boundary effect was investigated from the broad and asymmetric relaxation *** relaxation time for both the grain and grain boundary effect was also *** addition to this,we have also analyzed the normalized bode plot of imaginary part of impedance and electrical modulus which suggests the relaxation process dominated by the short-range movement of charge carriers.

关键词： Ferrite giant dielectric constant non-Debye relaxation.

Metal-containing nanomaterials as lubricant additives: state-of-the-art and future development

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Friction 2019年第2期7卷 93-116页

作者： Igor E.UFLYAND Vladimir A.ZHINZHILO Victoria E.BURLAKOVA Department of Chemistry Southern Federal University Department of Chemistry Don State Technical University

This review focuses on the effect of metal-containing nanomaterials on tribological performance in oil lubrication. The basic data on nanolubricants based on nanoparticles of metals, metal oxides, metal sulfides, nanocomposities, and rare-earth compounds are generalized. The influence of nanoparticle size, morphology, surface functionalization, and concentration on friction and wear is analyzed. The lubrication mechanisms of nanolubricants are discussed. The problems and prospects for the development of metal-containing nanomaterials as lubricant additives are considered. The bibliography includes articles published during the last five years.

关键词： coefficient of friction metal-containing nanomaterials nanolubricants nanoparticles wear

The ferroelectric field-effect transistor with negative capacitance

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npj Computational Materials 2022年第1期8卷 500-507页

作者： I.Luk’yanchuk A.Razumnaya A.Sené Y.Tikhonov V.M.Vinokur university of Picardie Laboratory of Condensed Matter Physics80039AmiensFrance Terra Quantum AG St.Gallerstrasse 16ACH-9400RorschachSwitzerland Faculty of Physics Southern Federal University5 Zorge str.344090Rostov-on-DonRussia

Integrating ferroelectric negative capacitance(NC)into the field-effect transistor(FET)promises to break fundamental limits of power dissipation known as Boltzmann ***,realizing the stable static negative capacitance in the non-transient non-hysteretic regime remains a daunting *** problem stems from the lack of understanding of how the fundamental origin of the NC due to the emergence of the domain state can be put in use for implementing the NC *** we put forth an ingenious design for the ferroelectric domain-based field-effect transistor with the stable reversible static negative *** dielectric coating of the ferroelectric capacitor enables the tunability of the negative capacitance improving tremendously the performance of the field-effect transistors.

关键词： transistor capacitance ferroelectric

Large piezoelectric anisotropy and high hydrostatic piezoelectric activity due to an appreciable orientation effect and porosity in novel 2-2-0 composites

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Journal of Advanced Dielectrics 2023年第2期13卷 38-48页

作者： Vitaly Yu.Topolov Andrey V.Krivoruchko Natalia V.Prutsakova Department of Physics Southern Federal University5 Zorge Street Rostov-on-Don 344090Russia don state technical university 1 Gagarin Square Rostov-on-Don 344000Russia

The polarization orientation effect and porosity effect on the piezoelectric properties and related parameters are studied in 2-2-type composites based on domain-engineered relaxor-ferroelectric[011]-poled single *** parameters,which are of great interest,are an anisotropy of the piezoelectric coefficients d_(3j)^(*),an anisotropy of the energy-harvesting figures of merit d_(3j)^(*)g_(3j)^(*) and the hydrostatic piezoelectric coefficient d_(h)^(*).An orientation of the main crystallographic axes in each polydomain single-crystal layer is described by anglesβandγ.Diagrams built for the first time show the(β,γ)regions,where a large anisotropy of d_(3j)^(*)(or d_(3j)^(*)g_(3j)^(*))is achieved,and where inequality d_(h)^(*)>1000 pC/N holds.A large local max d_(h)^(*)=1930 pC/N is achieved in a 2-2-0 PZN-0.065PT-based composite at the longitudinal piezoelectric coefficient d33*=2290 pC/N and figure of merit d*33g*33=1.02.10−9 Pa−*** aforementioned large parameters are to be of value in piezoelectric sensing,energy harvesting and hydroacoustics.

关键词： Piezo-active composite 2-2-type orientation effect porosity large piezoelectric anisotropy

The size-dependent elastohydrodynamic lubrication contact of a coated half-plane with non-Newtonian fluid

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Applied Mathematics and Mechanics(English Edition) 2021年第7期42卷 915-930页

作者： Jie SU Hongxia SONG Liaoliang KE S.M.AIZIKOVICH School of Mechanical Engineering Tianjin UniversityTianjin 300350China School of Mathematical Science Inner Mongolia UniversityHohhot 010021China Laboratory of Functionally Graded and Composite Materials Research and Education Center"Materials"Don State Technical UniversityRostov-on-Don 344000Russia

Based on the couple-stress theory,the elastohydrodynamic lubrication(EHL)contact is analyzed with a consideration of the size *** lubricant between the contact surface of a homogeneous coated half-plane and a rigid punch is supposed to be the non-Newtonian *** density and viscosity of the lubricant are dependent on fluid *** of film thickness,in-plane stress,and fluid pressure are calculated by solving the nonlinear fluid-solid coupled equations with an iterative *** effects of the punch radius,size parameter,coating thickness,slide/roll ratio,entraining velocity,resultant normal load,and stiffness ratio on lubricant film thickness,in-plane stress,and fluid pressure are *** results demonstrate that fluid pressure and film thickness are obviously dependent on the size parameter,stiffness ratio,and coating thickness.

关键词： elastohydrodynamic lubrication(EHL) non-Newtonian fluid size effect couple-stress theory coating