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Fractional-Linear Transformations of Operator Balls;Applications to Dynamical Systems

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Acta Mathematica Sinica,English Series 2006年第6期22卷 1687-1694页

作者： v.A.KHATSKEvICH v.A.SENDEROv Braude College College Campus P.O 23-2-156 Pyatnitskoe highway

The operator sets, which are the subject of this paper, have been studied in many papers where, under different restrictions on the generating operators, convexity, compactness in the weak operator topology, and nonemptiness were proved for sets of different classes under study. Then the results obtained were used in these papers to solve several applied problems. Namely, they played the key role in establishing the dichotomy of nonautonomous dynamical systems, with either continuous or discrete time. In the present paper, we generalize and sharpen the already known criteria and obtain several new criteria for convexity, compactness, and nonemptiness of several special operator sets. Then, using the assertions obtained, we construct examples of sets of the form under study which are nonconvex, noncompact in the weak operator topology, as well as empty, and are generated by ＂smooth＂ operators of a special class. The existence problem for such sets remained open until the authors of this paper announced some of its results.

关键词： Compactness Convexity Linear fractional relation Operator ball Krein space

IoT Enabled Microgrid Framework Using a Novel Dispersal Diffusion Artificial Neural Network Controller for Pv Systems and Wind Energy to Minimize Electrical Faults

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China Communications 2024年第12期21卷 217-230页

作者： v v vijetha Inti v S vakula Jawaharlal Nehru Technological University Kakinada University College of Engineering vizianagaram JNTUK

A system based on a Pv-Wind will ensure better efficiency and flexibility using lower energy ***,plenty of work is being focussed on Doubly Fed Induction Generators(DFIG)utilized in wind energy *** is found to be the best option in the Wind Energy Conversion Systems(WECS)to mitigate the issues caused by power *** this work,a new Artificial Neural Network(ANN)is proposed with the Diffusion and Dispersal strategy that works on Maximum Power Point Tracking(MPPT)along with Wind Energy Conversion System(WECS)to minimize electrical *** controller focus was not just to increase performance but also to reduce damage owing to any phase to phase fault or Phase to phase to ground *** ensure optimal MPPT for the proposed WECS,ANN achieves the optimal PI controller parameters for the indirect control of active and reactive power of *** optimal allocation and size of the DGs within the distributed system and for MPPT control are obtained using a population of *** generated solutions are evaluated and on being successful,the agents test their hypothesis again to create a positive feedback *** are carried out,and the proposed IoT framework efficiency indicates performance improvement and faster recovery against faults by 9 percent for phase to ground fault and by 7.35 percent for phase to phase fault.

关键词： dispersal diffusion search and artificial neural network maximum power point tracking(MPPT) photovoltaic(Pv)array wind energy conversion system(WECS)

Changes in the growth of Scots pine(Pinus sylvestris L.)stands in an urban environment in European Russia since 1862

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Journal of Forestry Research 2023年第5期34卷 1279-1287页

作者： Aleksandr v.Lebedev Department of Agricultural Meliorations Forestry and Land OrganizationRussian State Agrarian University-Moscow Timiryazev Agricultural AcademyTimiryazevskaya49MoscowRussia 127434

A century and a half ago,in the European part of Russia(Moscow),forest scientists established the first long-term observations of forests,many of which are under observation to the present *** the twentieth century,climate changes and,due to industrial development,forest areas were under air *** on observations from 157 sites,this study shows that the growth and density of Scots pine(Pinus sylvestris L.)have decreased by the end of the twentieth *** environment has changed,and the growth and development of plantations has *** yields(-34%stand volume)and their life expectancy(on average 50 years)have *** changes are critical for forestry and for the management of forests in urban *** to the decline in growth,ecosystem functions by urban forests has *** order to increase the sustainability of urban forests and the provision of ecosystem services,it is preferable to create multi-species stands with a complex structure.

关键词： Forest stand Scots pine Stand growth Urbanized environment Human footprint

Physical vapor transport growth and morphology of Bi2Se3 microcrystals

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Particuology 2016年第3期14卷 118-122页

作者： v.v. Atuchin S.v. Borisov T.A. Gavrilova K.A. Kokh N.v. Kuratieva N.v. Pervukhina Laboratory of Optical Materials and Structures Institute of Semiconductor Physics SB RAS Novosibirsk 630090 Russia Functional Electronics Laboratory Tomsk State University Tomsk 634050 Russia Laboratory of Semiconductor and Dielectric Materials Novosibirsk State University Novosibirsk 630090 Russia Laboratory of Crystul Chemistry Institute of Inorganic Chemistry SB RAS Novosibirsk 630090 Russia Laboratory of Nanodiagnostics and Nanolithography Institute of Semiconductor Physics SB RAS Novosibirsk 630090 Russia Laboratory of Crystal Growth Institute of Geology and Mineralogy SB RAS Novosibirsk 630090 Russia Geology and Mineralogy Department Novosibirsk State University Novosibirsk 630090 Russia Spintronics Laboratory Saint Petersburg State University Saint Petersburg 198504 Russia Laboratory of Research Methods of Composition and Structure of Functional Materials Novosibirsk State University Novosibirsk 630090 Russia

High-quality Bi2Se3 microcrystals were grown by the physical vapor transport （PvT） method without using a foreign transport agent. The microplate crystals grown under the optimal temperature gradient are well faceted and have dimensions up to -200 μm, The growth proceeds by the layer-by-layer mecha- nism with the formation of flat low-growth rate facets. The phase composition of the grown crystals was identified by the X-ray single crystal structure analysis in space group R3m, a = 4.1356（3）, C= 28.634（5）A, Z=3 （R=0.0147）. The most probable twin planes in the tetradymite structure were evaluated by the pseudo translational sublattice merhad.

关键词： Bi2Se3 Physical vapor transport Structure Twin

3D Kinematics of Classical Cepheids According to Gaia EDR3 Catalog

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Research in Astronomy and Astrophysics 2023年第4期23卷 1-14页

作者： v.v.Bobylev A.T.Bajkova Pulkovo Astronomical Observatory St.-Petersburg 196140Russia

The kinematics of about 2000 classical Cepheids of the Milky Way with data from Gaia EDR3 catalog has been *** some of these stars,there are line-of-sight *** the basis of the nonlinear rotation model,the parameters of the rotation curve of the Galaxy were *** circular linear rotation velocity of the near-solar neighborhood around the Galaxy center was v0=236±3 km s^(−1) for the assumed Sun's galactocentric distance R0=8.1±0.1 *** of residual velocities of Cepheids based on the linear Ogorodnikov–Milne model showed the presence of the following significantly different from zero gradients:∂U/∂x,∂U/∂z,∂v/∂x,∂v/∂z and∂W/∂x,which behave differently depending on the selection *** most interesting is the gradient∂W/∂x∼−0.5±0.1 km s^(−1) kpc^(−1)(positive rotation of this star system around the Galactic axis y,Ωy)since the velocities W are free of Galactic *** we have an indirect influence of various effects leading to a perturbation of the vertical velocities of the Galactic disk *** on a simpler model,a more accurate estimate of this rotation is obtained,Ωy=0.51±0.07 km s^(−1) kpc^(−1).

关键词： stars distances-Galaxy kinematics and dynamics-stars variables Cepheids

Effect of process parameters of pulsed current tungsten inert gas welding on weld pool geometry of titanium welds

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Acta Metallurgica Sinica(English Letters) 2010年第4期23卷 312-320页

作者： M.Balasubramanian v.Jayabalan v.Balasubramanian Department of Mechanical Engineering Velammal Engineering CollegeSurapetAnna University Department of Manufacturing Engineering Anna University Centre for Materials Joining & Research Department of Manufacturing EngineeringAnnamalai University

The effects of pulsing current parameters on weld pool geometry namely front height, back height, front width and back width of pulse current gas tungsten arc welded （GTAW） titanium alloy was analysed. Four factors, five levels, central composite design were used to develop empirical relationships, incorporating pulsed current parameters and weld pool geometry.

关键词： Gas tungsten arc welding Pulsed current Titanium alloy Design of experiments

How Common can the Origin of Clusters Cha Ⅰ, Cha Ⅱ, ∈Cha and η Cha be?

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Research in Astronomy and Astrophysics 2024年第5期24卷 28-34页

作者： v.v.Bobylev A.T.Bajkova Pulkovo Astronomical Observatory St.-Petersburg 196140Russia

The trajectories of the groupings η Cha,∈Cha and Cha I,Cha II,constructed backward in time,have been *** concluded that the hypothesis about the joint formation of all four of these clusters from one molecular cloud cannot be completely ***,10–15 Myr ago,all these four clusters were located at approximately the same height above the plane of the ***,the gas-dust clouds from which all these four clusters were formed were located on one broad *** is possible that the appearance of the Cha I,Cha II,∈Cha and η Cha clusters may be associated with the impact on such a front of shock waves formed after supernova explosions in the Scorpius–Centaurus *** estimates of the kinematic ages of the clusters Cha I and Cha II are obtained as 0.12±0.19 and 0.05±0.15,*** is shown that the minimum size of the Cha I-north and Cha I-south clusters corresponded to the time of 0.55±0.24 Myr and 0.04±0.18 Myr ago,respectively,and approximately1.5 Myr ago the distance between the trajectories of these two groupings was minimal.

关键词： stars distances-stars kinematics and dynamics-galaxies star formation

Effect of types of reinforcement on plastic hinge rotation parameters of RC beams under pushover and cyclic loading

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Earthquake Engineering and Engineering vibration 2015年第3期14卷 503-516页

作者： v.v.S.Surya Kumar Dadi Pankaj Agarwal Department of Civil Engineering Institute of Technology Guru Ghasidas Vishwavidyalaya Bilaspur (C.G.) India Assistant Professor Department of Earthquake Engineering Indian Institute of Technology Roorkee

Experimental evaluation of reinforced concrete beam specimens with different characteristics of reinforcement subjected to pushover and cyclic loading is *** hinge rotation parameters are determined based on the idealization of pushover and hysteresis curves of reinforced concrete beam specimens constructed in two percentage of reinforcement(0.471%and 0.71%) with different ductile *** experimental test results provide a clear demarcation of the effect of types of loading and the types of reinforcement on the nonlinear performance characteristics of beam *** results are helpful to update the nonlinear modeling parameters of beam components for the specific type of reinforcement used in the construction of a *** updated non-linear modeling parameters of beam components in lumped plasticity model are compared with the values of ASCE/SEI 41-06(2007) used for the performance based design of structures.

关键词： concrete structures pushover loads cyclic loads hy

La^(3+) -doped SrBi_2Ta_2O_9 thin films for FRAM synthesized by sol-gel method

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Journal of Rare Earths 2014年第3期32卷 277-281页

作者： v.v.Sidsky A.v.Semchenko A.G.Rybakov v.v.Kolos A.S.Turtsevich A.N.Asadchyi W.Strek F.Skorina Gomel State University JSC ?INTEGRAL? 121A Kazintsa st. Minsk 220108 Belarus Institute of Low Temperature and Structures Research PAN Okolna st.2 Wroclaw Poland

This paper discusses the possibility of synthesis of SBTL sol-gel films for use as active layers for non-volatile memory （FRAM）. La-doped SrBi2Ta209 thin films were synthesized by sol-gel method on Pt/TiO2/BPSG/SiO2/Si substrates. The structural features of the surface （AFM）, crystallization behavior （XRD） during the heating and ferroelectric properties of synthesized films were discussed. It was shown that an optimum surface structure and a high share of perovskite phase of SBTL-films were compared to SBT-films （Theating=800 ℃）. Achieved ferroelectric parameters suggested the possibility of using synthesized SBTL sol-gel films in non-volatile memory devices.

关键词： ferroelectric thin films sol-gel method lanthanum ion non-volatile memory rare earths