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Composite Control of Nonlinear Singularly Perturbed Systems via Approximate Feedback Linearization

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international Journal of Automation and computing 2020年第4期17卷 610-620页

作者： aleksey Kabanov Vasiliy Alchakov Sevastopol State University Sevastopol 299053Russian Federation

This article is devoted to the problem of composite control design for continuous nonlinear singularly perturbed(SP)system using approximate feedback linearization(AFL)*** essence of AFL method lies in the feedback linearization only of a certain part of the original nonlinear *** to AFL approach,we suggest to solve feedback linearization problems for continuous nonlinear SP system by reducing it to two feedback linearization problems for slow and fast subsystems *** resulting AFL control is constructed in the form of asymptotic composition(composite control).Standard procedure for the composite control design consists of the following steps:1)system decomposition,2)solution of control problem for fast subsystem,3)solution of control problem for slow subsystem,4)construction of the resulting control in the form of the composition of slow and fast *** main difficulty during system decomposition is associated with dynamics separation condition for nonlinear SP *** overcome this,we propose to change the sequence of the design procedure:1)solving the control problem for fast state variables part,2)system decomposition,3)solving the control problem for slow state variables part,4)construction of the resulting composite *** this way,fast feedback linearizing control is chosen so that the dynamics separation condition would be met and the fast subsystem would be *** application of the proposed approach is illustrated through several examples.

关键词： Approximate feedback linearization(AFL) composite control nonlinear singularly perturbed system order reduction decomposition

The effect of the concentration of plastic waste on the formation of reaction products of the Ti-PET system

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Green Chemical Engineering 2024年第3期5卷 374-382页

作者： aleksey E.Matveev Tomsk Scientific Center of the Siberian Branch of the Russian Academy of Sciences 634055TomskAkademicheskii Prospekt 10/4Russia

The paper presents research results of the synthesis,phase composition,and structure of products obtained by highly exothermic reactions between Ti and C10H8O4mixture components,depending on the plastic waste concentration and Ti powder dispersiveness,density of initial samples,and synthesis *** dependence of the phase composition and structure of the synthesis products on the concentration of the polymer(plastic)component in the initial Ti-PET(C10H8O4)system was *** the plastic waste content is 20 wt%to 25 wt%,synthesis products contain TiC0.5O0.5-TiC0.6-0.75particle *** growth in the polyethylene terephthalate content from 30 wt%to 45 wt%leads to the formation of synthesis products consisting of titanium carbide(TiC0.6-1.0).The gaseous byproduct composition of the exothermic reaction is investigated for the Ti--C10H8O4mixture *** is found that the gaseous by-product mostly contains hydrogen and carbon monoxide as well as impurities of different hydrocarbons(methane,acetylene,ethane,ethene)and carbon *** maximum adiabatic temperature of the gas combustion temperature is 2080℃,which demonstrates the possibility of using gas as a fuel for energy generation *** on the data obtained,it is possible to create a basis for a new plastic waste technology to fabricate carbide-containing materials.

关键词： Plastic waste Titanium carbide Green technology Hydrogen synthesis

Polyhydroxybutyrate/Hydroxyapatite Highly Porous Scaffold for Small Bone Defects Replacement in the Nonload-bearing Parts

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Journal of Bionic Engineering 2017年第4期14卷 648-658页

作者： Fedor Senatov Natalia Anisimova Mikhail Kiselevskiy aleksey Kopylov Viktor Tcherdyntsev aleksey Maksimkin National University of Science and Technology MiSiS Leninskiy pr. 4 Moscow 119049 Russian Federation N.N. Blokhin Russian Cancer Research Center Kashirskoye sh. 23 Moscow 115478 Russian Federation

in the present work, Polyhydroxybutyrate （PHB）/Hydroxyapatite （HA） porous composites （10%, 20%, 30 %, 40%, 50% weight HA） were obtained by sintering. PHB/20% HA optimally combines satisfactory mechanical properties with a high content of the bioactive component （HA）. Porous PHB/20% HA scaffolds have shown high mechanical properties （compressive strength of 106 MPa and Young＇s modulus of 901 MPa）. A high volume fraction of interconnected pores （〉 50 vol.%） was achieved with pore size of 50 grn - 500 gm. Biocompatibility of porous pure PHB and PHB/20%HA, as its osseointegration were assessed in vitro and after implantation in laboratory animals. PHB/20% HA （-5% ＋ 0.9%） and pure PHB ~3% ~ 1.4%） samples after 24 hours of incubation with human leucocytes showed no significant level of cytotoxicity when p = 0.648 （p-value）. in vitro massive adhesion of mouse Multipotent Mesenchymal Stromal Cells （MMSC） to the surface of both porous samples was shown. PHB/20% HA induced more intensive MMSC proliferation compared to pure PHB, which are 31% ＋ 6.1% and 20% ＋ 5.7 % respectively when p = 0.039. We observed the resorption （implant surface area was reduced by 49 %） and integration of the porous PHB/20% HA samples into surrounding tissues after 30 days of implantation. The signs of osteoclasts accumulation, neo-angigenesis and new bone formation were observed, which make PHB/20% HA promising for bone tissue engineering.

关键词： polyhydroxybutyrate hydroxyapatite scaffold porous structure implant bone regeneration

Rational design and synthesis of noble-metal nanoframes for catalytic and photonic applications

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National Science Review 2016年第4期3卷 520-533页

作者： Xue Wang aleksey Ruditskiy Younan Xia The Wallace H.Coulter Department of Biomedical Engineering Georgia Institute of Technology and Emory University State Key Laboratory for Oxo Synthesis and Selective Oxidation Suzhou Research InstituteLanzhou Institute of Chemical PhysicsChinese Academy of Sciences School of Chemistry and Biochemistry Georgia Institute of Technology

Nanoframes are unique for their 3D,highly open *** made of noble metals,they are atractive for use as heterogeneous catalysts because of their large speciic surface areas,high densities of catalytically active sites and low vulnerability toward *** promise to enhance the catalytic activity and durability while reducing the material loading and *** nanoframes composed of Au and/or Ag,they also exhibit highly tunable plasmonic properties similar to those of *** article presents a brief account of recent progress in the design,synthesis and utilization of noble-metal *** start with a discussion of the synthetic strategies,including those involving site-selected deposition and etching,as well as dealloying of both hollow and solid *** then highlight some of the applications enabled by noble-metal ***,we discuss the challenges and trends with regard to future development.

关键词： noble metal nanoframe nanomaterial synthesis catalysis plasmonics

Normal Crossings Singularities for Symplectic Topology:Structures

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Acta Mathematica Sinica,English Series 2024年第1期40卷 107-160页

作者： Mohammad FARAJZADEH-TEHRANi Mark MCLEAN aleksey ZiNGER The University of iowa MacLean HallIowa CityIA 52241 Department of Mathematics Stony Brook UniversityStony BrookNY 11794

Our previous papers introduce topological notions of normal crossings symplectic divisor and variety,show that they are equivalent,in a suitable sense,to the corresponding geometric notions,and establish a topological smoothability criterion for normal crossings symplectic *** present paper constructs a blowup,a complex line bundle,and a logarithmic tangent bundle naturally associated with a normal crossings symplectic divisor and determines the Chern class of the last *** structures have applications in constructions and analysis of various moduli *** a corollary of the Chern class formula for the logarithmic tangent bundle,we refine Aluffi’s formula for the Chern class of the tangent bundle of the blowup at a complete intersection to account for the torsion and extend it to the blowup at the deepest stratum of an arbitrary normal crossings divisor.

关键词： Normal crossings divisor Chern class Logarithmic tangent bundle

Helix unwinding in ferroelectric liquid crystals induced by tilted electric field

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Chinese Physics B 2015年第7期24卷 341-344页

作者： Nail G.Migranov aleksey A.Kudreyko Bashkir State Pedagogical University Department of General and Theoretical Physics Ufa State Petroleum Technological University Department of Physics

Helix unwinding in ferroelectric liquid crystals induced by an electric field is theoretically studied on the basis of the continuum theory. By applying a weak electric field tilted to the smectic layers, the contribution of the dielectric interaction energy density to the total free energy density is increased. Approximation methods are used to calculate the free energy for different tilt angles between the electric field and the smectic layers. The obtained results suggest selecting the optimal number of pitches in the film that matches to the minimum of the free energy.

关键词： ferroelectric liquid crystals helicoidal structure thin films Euler's equation

Electro–optic response in thin smectic C* film with chevron structures

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Chinese Physics B 2016年第12期25卷 337-343页

作者： aleksey A Kudreyko Nail G Migranov Dana N Migranova Ufa State Petroleum Technological University Department of Physics Bashkir State Pedagogical University Department of General and Theoretical Physics

The effects in electrostatic models of chevron surface-stabilized ferroelectric liquid crystals are investigated through numerical modeling. To study smectic C＊ director distribution within the cell, we consider two nonlinear approaches： the chevron interface does not interplay with the electric field; the electric field interplays with the chevron interface. The obtained results of the director field distribution are compared with the earlier linearized studies. We find that whether or not the electric field interplays with the chevron interface, the electro-optic response requires a generalized approach for its description. The threshold electric field, which is necessary for switching between two stable director states in the chevron cell is evaluated. This study suggests that, in many cases of practical interest, electro-optic response to the electric field and the threshold electric field can be precisely estimated. We argue that, beside being numerically efficient, our approach provides a convenient and a novel standpoint for looking at the electro-optic response problem.

关键词： surface-stabilized ferroelectric liquid crystal chevron structure thin films bistability Euler'sequation

Ooidal ironstones in the Meso-Cenozoic sequences in western Siberia: assessment of formation processes and relationship with regional and global earth processes

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Journal of Palaeogeography 2020年第1期9卷 88-108页

作者： Maxim Rudmin Santanu Banerjee Elshan Abdullayev aleksey Ruban Ekaterina Filimonenko Elena Lyapina Roman Kashapov aleksey Mazurov Division for Geology School of Earth Sciences and EngineeringTomsk Polytechnic University634050 TomskRussia Department of Earth Sciences Indian Institute of Technology BombayPowaiMumbai 400076MaharashtraIndia Department of Geoscience French-Azerbaijani University(UFAZ)AZ1000 BakuAzerbaijan institute of Monitoring of Climatic and Ecological System of SB of RAS 634055 TomskRussia.

This study investigates the process of formation of ooidal ironstones in the Upper Cretaceous-Paleogene succession in western *** formation of such carbonate-based ironstones is a continuing problem in sedimentary geology,and in this study,we use a variety of data and proxies assembled from core samples to develop a model to explain how the ooidal ironstones *** on pyrite framboids and geochemical redox proxies reveals three intervals of oceanic hypoxia during the deposition of marine ooidal ironstones in the Late Cretaceous to the Early Paleogene Bakchar ironstone deposit in western Siberia;the absence of pyrite indicates oxic conditions for the remaining *** goethite formed in oxic depositional condition,chamosite,pyrite and siderite represented hypoxic *** pyrite crystals form through a series of transition originating from massive aggregate followed by normal and polygonal *** associated with goethite-chamosite ironstones,encompassing hypoxic intervals exhibit positive cerium,negative europium,and negative yttrium *** anomalies,associated with the initial stages of hypoxia,correlate with global volcanic *** sensitive proxies and ore mineral assemblages of deposits reflect hydrothermal *** and global volcanism possibly induced hydrothermal convection in the sedimentary cover of western Siberia,and released iron-rich fluid and methane in coastal and shallow marine *** investigation,therefore,reveals a potential geological connection between Large igneous Provinces(LiPs),marine hypoxia,rifting and the formation of ooidal ironstones in ancient West Siberian Sea.

关键词： Ooidal ironstone Pyrite framboids Late Cretaceous Early Paleogene Western Siberia Bakchar ironstone deposit Redox conditions

Algorithms for automatic measurement of SiS-type hysteretic underdamped Josephson junction’s parameters by current-voltage characteristics

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Journal of Electronic Science and Technology 2023年第4期21卷 60-74页

作者： aleksey G.Vostretsov Svetlana G.Filatova Laboratory of Quantum Cryogenic Electronics Novosibirsk State Technical UniversityNovosibirsk630073Russia Chinakal institute of Mining Siberian BranchRussian Academy of SciencesNovosibirsk630091Russia

Some electrical parameters of the SiS-type hysteretic underdamped Josephson junction(JJ)can be measured by its current-voltage characteristics(iVCs).Currents and voltages at JJ are commensurate with the intrinsic noise level of measuring *** leads to the need for multiple measurements with subsequent statistical *** this paper,the digital algorithms are proposed for the automatic measurement of the JJ parameters by *** algorithms make it possible to implement multiple measurements and check these JJ parameters in an automatic mode with the required *** complete sufficient statistics are used to minimize the root-mean-square error of parameter measurement.A sequence of current pulses with slow rising and falling edges is used to drive JJ,and synchronous current and voltage readings at JJ are used to realize measurement *** algorithm performance is estimated through computer *** significant advantage of the proposed algorithms is the independence from current source noise and intrinsic noise of current and voltage meters,as well as the simple implementation in automatic digital measuring *** proposed algorithms can be used to control JJ parameters during mass production of superconducting integrated circuits,which will improve the production efficiency and product quality.

关键词： Algorithm design and analysis Critical current Current-voltage characteristics(iVCs) Josephson junction(JJ) Measurement errors Parameter estimation