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    Wyświetlanie 1-54 z 54
    Tytuł:
    Homoclinic Chaos in Generalized Henon-Heiles System
    Autorzy:
    Kasperczuk, S.
    Powiązania:
    https://bibliotekanauki.pl/articles/1943893.pdf
    Data publikacji:
    1995-12
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    05.45.+b
    Opis:
    This paper considers the generalized Henon-Heiles system, defined by the Hamiltonian Η = (p$\text{}_{1}^{2}$ + p$\text{}_{2}^{2}$ + Αq$\text{}_{1}^{2}$ + Bq$\text{}_{2}^{2}$)/2 + Cq$\text{}_{1}^{2}$q$\text{}_{2}$ + Dq$\text{}_{2}^{3}$. Melnikov's method is used to prove the existence of nondegenerate homoclinic orbits near two integrable cases: (o) C = 0; A, B, D arbitrary; (i) A = B; C = 3D. The existence of such orbits precludes the existence of analytic second integrals.
    Źródło:
    Acta Physica Polonica A; 1995, 88, 6; 1073-1080
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Turbulence in the One-Dimensional Complex Ginzburg-Landau Equation
    Autorzy:
    Zubrzycki, A.
    Powiązania:
    https://bibliotekanauki.pl/articles/1933422.pdf
    Data publikacji:
    1995-06
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    05.45.+b
    Opis:
    The transition to phase and amplitude turbulent states in the one-dimensional complex Ginzburg-Landau equation is investigated by a numerical simulation. In order to describe existing attractors quantitatively, the largest Lyapunov exponent is estimated. The largest Lyapunov exponent is positive but small for the phase turbulence and it is much larger for the amplitude turbulence. Moreover, it seems independent on the system size.
    Źródło:
    Acta Physica Polonica A; 1995, 87, 6; 925-932
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Autocorrelation Function and Mutual Information from Short Experimental Time Series
    Autorzy:
    Zduniak, A.
    Łusakowski, J.
    Powiązania:
    https://bibliotekanauki.pl/articles/1932093.pdf
    Data publikacji:
    1995-01
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    05.45.+b
    Opis:
    A nonlinear dynamics of self-generated current oscillations in semi-insulating GaAs was studied by the reconstruction of an attractor from a short (14500 points) time series. Two methods of choosing of a time constant (τ) for this reconstruction are compared. One of them assumes τ to be an argument of the first zero of the autocorrelation function and the other takes τ as an argument of the first minimum of the mutual information. It is shown that for periodic oscillations both methods are equivalent, but for chaotic ones only the mutual information gives a time constant which does not depend on a time series used for calculations.
    Źródło:
    Acta Physica Polonica A; 1995, 87, 1; 257-260
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Peano Dynamics as a Model for Turbulence and Strange Nonchaotic Behaviour
    Autorzy:
    El Naschie, M.
    Powiązania:
    https://bibliotekanauki.pl/articles/1887906.pdf
    Data publikacji:
    1991-07
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    05.45.+b
    Opis:
    The note outlines a scenario for a two-dimensional dynamic system to possess strange nonchaotic behaviour in the presence of two frequency quasi periodic forcing. Implications for turbulence are also discussed.
    Źródło:
    Acta Physica Polonica A; 1991, 80, 1; 3-13
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Quantum Implications of Ray Splitting
    Autorzy:
    Blümel, R.
    Powiązania:
    https://bibliotekanauki.pl/articles/1968499.pdf
    Data publikacji:
    1998-01
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    05.45.+b
    Opis:
    Ray splitting is a universal phenomenon that occurs in all wave systems with sharp interfaces. Quantum implications of ray splitting are: (i) the importance of non-Newtonian orbits for the density of states in the semiclassical limit, (ii) ray-splitting corrections to the average density of states and (iii) the need to include non-Newtonian orbits in trace formulas for the oscillating part of the density of states. The signatures of non-Newtonian orbits in the density of states have recently been identified experimentally.
    Źródło:
    Acta Physica Polonica A; 1998, 93, 1; 7-10
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Spatio-Temporal Dynamics of Chain of Coupled Impact Pendulums
    Autorzy:
    Stępień, R.
    Kosiński, R. A.
    Powiązania:
    https://bibliotekanauki.pl/articles/1964195.pdf
    Data publikacji:
    1997-06
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    05.45.+b
    Opis:
    A chain of N, one-dimensional, impact pendulums is investigated using numerical solutions of equations of motion. Ranges of periodic, mixed and chaotic motion are found using spatio-temporal diagrams. A correlation function and power spectrum density functions are calculated for these digitized diagrams. Influence of the coupling strength k and the number of pendulums N on the dynamics of the system is discussed.
    Źródło:
    Acta Physica Polonica A; 1997, 91, 6; 1053-1059
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Spatial Inhomogeneity of Periodic and Chaotic Attractors of a Driven Damped Nonlinear Schrödinger Equation
    Autorzy:
    Zubrzycki, A.
    Powiązania:
    https://bibliotekanauki.pl/articles/1943890.pdf
    Data publikacji:
    1995-12
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    05.45.+b
    Opis:
    The driven damped nonlinear Schrödinger equation is solved numerically and different attractors - periodic and chaotic ones - are obtained for different ranges of the forcing field amplitude. It is shown that these attractors are in both cases spatially nonuniform in time. Spatial inhomogeneity of the chaotic attractor is investigated by the estimation of the correlation dimension at different space points.
    Źródło:
    Acta Physica Polonica A; 1995, 88, 6; 1067-1072
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Application of Time-Delay Reconstruction Method for Examination of Spatial Inhomogeneity of Dynamical Systems
    Autorzy:
    Zubrzycki, A.
    Sukiennicki, A.
    Powiązania:
    https://bibliotekanauki.pl/articles/1964193.pdf
    Data publikacji:
    1997-06
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    05.45.+b
    Opis:
    Three spatially extended one-dimensional dynamical systems are examined by numerical simulations and the time-delay technique is applied to find their dynamics at different positions in space. On the basis of this technique the correlation dimension is calculated from time series obtained at different positions. It is found that the value of the correlation dimension may vary from one position to another, reflecting the spatial inhomogeneity of the system.
    Źródło:
    Acta Physica Polonica A; 1997, 91, 6; 1043-1052
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Stochastic Resonance in System with On-Off Intermittency
    Autorzy:
    Krawiecki, A.
    Powiązania:
    https://bibliotekanauki.pl/articles/1968461.pdf
    Data publikacji:
    1997-12
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    05.45.+b
    05.40.+j
    Opis:
    Stochastic resonance in a chaotic threshold-crossing system exhibiting on-off intermittency and attractor bubbling: the logistic map with the control parameter varying randomly or chaotically in time is studied in the case of weak additive and multiplicative periodic forcing. In both cases signal-to-noise ratio shows dependence on the forcing frequency; in the case of multiplicative forcing this dependence appears even for very small frequencies. It is shown that this is a result of a very long characteristic time scale, typical of systems with on-off intermittency.
    Źródło:
    Acta Physica Polonica A; 1997, 92, 6; 1101-1108
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Classical Paths and Semiclassical Ghosts
    Autorzy:
    Haake, F.
    Powiązania:
    https://bibliotekanauki.pl/articles/1931270.pdf
    Data publikacji:
    1994-04
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    03.65.Sq
    05.45.+b
    Opis:
    The semiclassical approximation for the quantum propagator of the kicked top is shown to involve not only classical periodic orbits but also complex generalizations thereof. Such ghost trajectories have complex actions S and thus contribute exponentially small terms as ħ → O. However, close to bifurcations ImS can be very small whereupon ghosts become quite visible.
    Źródło:
    Acta Physica Polonica A; 1994, 85, 4; 693-698
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Fractal Dimensions from Chaotic Oscillations in Semi-Insulating GaAs
    Autorzy:
    Zduniak, A.
    Łusakowski, J.
    Powiązania:
    https://bibliotekanauki.pl/articles/1929673.pdf
    Data publikacji:
    1993-09
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    05.45.+b
    72.20.Ht
    Opis:
    Relaxation and domain current oscillations in undoped semi-insulating GaAs were observed at room temperature for a broad range of voltage applied to a sample. The oscillations were characterized by a reconstruction of an attractor of the system. An analysis of the attractor helped to discriminate between the two likes of oscillations. A transition from one like of oscillations to the other was connected with a chaotization of the current. A chaotic state of the system was analyzed by calculations of fractal dimensions D$\text{}_{q}$ for -0.6 < g < 40 and the f(α) function.
    Źródło:
    Acta Physica Polonica A; 1993, 84, 3; 575-578
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    On Electrons in Quantum Chaos State in Doped Fullerene Crystal
    Autorzy:
    Koper, A.
    Mucha, M.
    Powiązania:
    https://bibliotekanauki.pl/articles/2012904.pdf
    Data publikacji:
    2000-01
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    05.45.+b
    61.48.+c
    Opis:
    We show that band electrons in A$\text{}_{n}$C$\text{}_{60}$ crystal (C$\text{}_{60}$ fullerene doped with alkali ions A) are in highly chaotic quantum state. We describe intensity of the chaos by means of the Shannon information entropy, which we calculate using single particle Bloch functions. The entropy provides a quantitative measure of scars as well as degree of electrons delocalization in gaps between C$\text{}_{60}$ molecules. Implications of our results for conductivity in A$\text{}_{3}$C$\text{}_{60}$ are discussed.
    Źródło:
    Acta Physica Polonica A; 2000, 97, 1; 229-232
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Regular and Chaotic Behaviour of a Kicked Damped Spin
    Autorzy:
    Hołyst, J.
    Sukiennicki, A.
    Powiązania:
    https://bibliotekanauki.pl/articles/1920483.pdf
    Data publikacji:
    1992-03
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    05.45.+b
    75.10.Hk
    Opis:
    The dynamics of a kicked, anisotropic, damped spin is reduced to a two-dimensional map. This map exhibits such features as bifurcation diagrams, regular or chaotic attractors/repellors and intermittent-like transitions between two strange attractors. With increase of damping a transition from chaos to the fixed point attractor occurs. On the contrary to the Hamiltonian case the type of magnetic anisotropy plays a crucial role for damped models.
    Źródło:
    Acta Physica Polonica A; 1992, 81, 3; 353-360
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Non Saturation of Energy in a Quantum Kicked Oscillator
    Autorzy:
    Daly, M. V.
    Hefernan, D. M.
    Powiązania:
    https://bibliotekanauki.pl/articles/1945399.pdf
    Data publikacji:
    1996-05
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    03.65.-w
    05.45.+b
    Opis:
    We present a quantum mapping for the kicked harmonic oscillator which relates the probability amplitudes of the undriven oscillator's eigenfunctions over successive kicks. We show how for various kick strengths the wave functions have a linear energy increase up to the limit imposed by the finite matrix size of the evolution matrix. We use this linear energy increase to define a quantum diffusion-like coefficient. We also show how this increase in energy causes the wave functions to spread out and become diffuse with little or no discernible structure. This model may serve as a paradigm for the study of quantum chaos.
    Źródło:
    Acta Physica Polonica A; 1996, 89, 5-6; 571-580
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Polarization Dependence of Microwave "ionization" of Excited Hydrogen Atoms
    Autorzy:
    Koch, P. M.
    Powiązania:
    https://bibliotekanauki.pl/articles/1968532.pdf
    Data publikacji:
    1998-01
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    32.80.Rm
    05.45.+b
    42.50.Hz
    Opis:
    After a brief review of the ionization of excited hydrogen atoms by a linearly polarized field, we discuss experimental results for the polarization dependence of this process. Experiments at ω/2π = 9.904 GHz used two different ranges of principal quantum number n$\text{}_{0}$ between 29 and 98. At low scaled frequencies, Ω ≲ 0.1, ionization data for certain narrow ranges of n$\text{}_{0}$ exhibit striking sensitivity to fields with elliptical polarization not too far from circular polarization. Classical calculations reproduce this behavior and show it to be the result of 2ω driving terms that appear when the Hamiltonian is transformed to a frame rotating at ω. It shows how higher-dimensional dynamics can influence the ionization and be used to control it when the polarization departs from linear or circular polarization. At higher scaled frequencies, 0.6 ≲ Ω$\text{}_{0}$ ≲ 1.4, near the onset of ionization circularly and elliptically polarized data show surprising similarities with linearly polarized data in a parameter regime where the ionization dynamics is dominated by the influence of the pendulumlike resonance zone centered at scaled frequency n$\text{}_{0}^{3}$ω ≡ Ω$\text{}_{0}$ = 1. The stabilizing influence of this zone can be understood classically, but nonclassical stability associated with quantal separatrix states at its edge is a semiclassical effect.
    Źródło:
    Acta Physica Polonica A; 1998, 93, 1; 105-133
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Simple Quantitative Analysis of Spatio-Temporal Diagrams for Domain Wall Dynamics
    Autorzy:
    Kosiński, R. A.
    Stępień, R.
    Powiązania:
    https://bibliotekanauki.pl/articles/1932111.pdf
    Data publikacji:
    1995-03
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    05.45.+b
    75.10.Hk
    75.60.Ch
    Opis:
    A quantitative analysis of spatio-temporal diagrams, which describe the dynamics of a chosen, spatially extended dynamic system (a domain wall in a thin magnetic garnet film) is presented. Two quantifiers characterizing such diagrams - a correlation function and power spectrum density function - were calculated using solutions of equations of motion. It was found that introducing these quantifiers to the analysis of spatio-temporal diagrams enables one to effectively characterize the type and the properties of motion of the considered system.
    Źródło:
    Acta Physica Polonica A; 1995, 87, 3; 575-583
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    On the Route to Chaos for Domain Walls with a Model of Stray Field
    Autorzy:
    Sukiennicki, A.
    Kosiński, R. A.
    Żebrowski, J. J.
    Powiązania:
    https://bibliotekanauki.pl/articles/1931285.pdf
    Data publikacji:
    1994-05
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    05.45.+b
    75.10.Hk
    75.60.Ch
    Opis:
    The route to chaos of domain wall in thin magnetic film, which is described by Słonczewski's equations of motion, is analyzed numerically. Hagedorn's model of surface stray field is applied. Ranges of periodic and chaotic wall motion as a function of constant in time, drive field are found. Comparison of results with those obtained for Hubert's model of the stray field is made.
    Źródło:
    Acta Physica Polonica A; 1994, 85, 5; 791-796
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Parking in the City: an Example of Limited Resource Sharing
    Autorzy:
    Šeba, P.
    Powiązania:
    https://bibliotekanauki.pl/articles/1585124.pdf
    Data publikacji:
    2009-11
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    05.45.+b
    05.20.-y
    05.60.+w
    Opis:
    During the attempt to park a car in the city the drivers have to share limited resources (the available roadside). We show that this fact leads to a predictable distribution of the distances between the cars that depends on the length of the street segment used for the collective parking. We demonstrate in addition that the individual parking maneuver is guided by generic psychophysical perceptual correlates. Both predictions are compared with the actual parking data collected in the city of Hradec Kralove (Czech Republic).
    Źródło:
    Acta Physica Polonica A; 2009, 116, 5; 779-782
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    On-Off Intermittency in Randomly Driven Parallel Pumping
    Autorzy:
    Krawiecki, A.
    Powiązania:
    https://bibliotekanauki.pl/articles/1964771.pdf
    Data publikacji:
    1997-08
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    75.30.Ds
    05.45.+b
    76.50.+g
    Opis:
    A model of parallel pumping with many interacting parametric spin-wave pairs is investigated numerically. On-off intermittency is obtained in the time series of absorption when the rf field amplitude is varied randomly in time, slowly in comparison with the rf field frequency, and when its mean value exceeds slightly the parallel pumping instability threshold. If the interactions between parametrically and thermally excited spin waves are neglected, only one parametric spin-wave pair is strongly excited and exhibits intermittent behaviour. In the opposite case a packet of parametric spin waves with frequencies close to half the pumping frequency may be excited. This modifies quantitatively, but not qualitatively the intermittency characteristics in the presence of thermal noise.
    Źródło:
    Acta Physica Polonica A; 1997, 92, 2; 465-468
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Synchronization Among Spin-Wave Amplitudes in Chaotic Nonlinear Ferromagnetic Resonance
    Autorzy:
    Krawiecki, A.
    Powiązania:
    https://bibliotekanauki.pl/articles/2013977.pdf
    Data publikacji:
    2000-05
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    76.50.+g
    75.30.Ds
    05.45.+b
    Opis:
    A model of chaos in high-power ferromagnetic resonance in coincidence regime, based on three-magnon interactions of the uniform mode with a group of pairs of parametric spin waves, is investigated numerically. The results are interpreted from the point of view of chaotic synchronization theory. If all spin waves are identical, all of them are excited above the first-order Suhl instability threshold and in the chaotic regime their amplitudes show marginal synchronization, i.e. they differ only by a multiplicative factor, constant in time. If spin waves have slightly different instability thresholds, only one or few of them are excited. In the latter case, addition of weak thermal noise changes the results qualitatively. For low rf field amplitude, but above the threshold for chaos, still only few spin-wave pairs are excited above the thermal level. For higher rf field amplitude all spin waves in the group are excited, and their amplitudes are not synchronized. These results suggest that low correlation dimension of chaotic attractors, observed often in nonlinear ferromagnetic resonance, can be connected with chaotic synchronization among spin-wave amplitudes, in particular just above the threshold for chaos.
    Źródło:
    Acta Physica Polonica A; 2000, 97, 5; 947-950
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Chaos Assisted Tunneling and Nonspreading Wave Packets
    Autorzy:
    Zakrzewski, J.
    Delande, D.
    Buchleitner, A.
    Powiązania:
    https://bibliotekanauki.pl/articles/1968540.pdf
    Data publikacji:
    1998-01
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    05.45.+b
    32.80.Rm
    42.50.Hz
    Opis:
    Consider an initial state lying on a primary resonance island. The state may tunnel into the chaotic sea surrounding it and further escape to infinity via chaotic diffusion. Properties of transport in such a situation are studied on an exemplary system - the hydrogen atom driven by microwaves. We show that the combination of tunneling followed by chaotic diffusion leads to peculiar large scale fluctuations of the AC Stark shift and ionization rates. An appropriate random matrix model describes accurately these statistical properties.
    Źródło:
    Acta Physica Polonica A; 1998, 93, 1; 179-186
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    On-Off Intermittency in Randomly Driven Nonlinear Ferromagnetic Resonance
    Autorzy:
    Krawiecki, A.
    Sukiennicki, A.
    Powiązania:
    https://bibliotekanauki.pl/articles/1943965.pdf
    Data publikacji:
    1996-01
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    05.45.+b
    76.50.+g
    75.30.Ds
    Opis:
    Simple models of nonlinear ferromagnetic resonance are considered which describe perpendicular resonance and parallel pumping with the rf field amplitude changing randomly and chaotically in time. On-off intermittency is obtained from the numerical solution of the equations of motion for the spin-wave amplitudes when the mean value of the rf field amplitude exceeds the Suhl instability threshold. Possible experimental applications are discussed.
    Źródło:
    Acta Physica Polonica A; 1996, 89, 1; 37-45
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Chaotic Dynamics of Periodically Driven Domain Walls in Magnetic Garnet Films
    Autorzy:
    Kosiński, R. A.
    Sukiennicki, A.
    Powiązania:
    https://bibliotekanauki.pl/articles/1945374.pdf
    Data publikacji:
    1996-04
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    05.45.+b
    75.10.Hk
    75.60.Ch
    Opis:
    The motion of domain walls in thin garnet films was investigated numerically using Slonczewski's equations of wall motion for the case of periodic drive field. The type of the wall motion was analyzed by observation of phase trajectories and spatio-temporal diagrams. It was found that depending on the period and amplitude of the drive field the motion of the wall is periodic or chaotic, reflecting the character of the dynamical processes connected with horizontal Bloch lines in the wall.
    Źródło:
    Acta Physica Polonica A; 1996, 89, 4; 495-501
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Chaotic Dynamics of Domain Walls in Magnetic Garnet Films with In-Plane Fields
    Autorzy:
    Sukiennicki, A.
    Kosiński, R. A.
    Powiązania:
    https://bibliotekanauki.pl/articles/1933423.pdf
    Data publikacji:
    1995-06
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    05.45.+b
    75.10.Hk
    75.60.Ch
    Opis:
    Chaotic dynamics and routes to chaos of domain walls in magnetic bubble garnet materials in the presence of in-plane fields were investigated numerically using Slonczewski's equations of motion. Connection between the structure of the wall and the character of the attractor was found. The in-plane field can play a role of the factor controlling chaos.
    Źródło:
    Acta Physica Polonica A; 1995, 87, 6; 933-938
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    On-Off Intermittency and Peculiar Properties of Attractors in a Simple Model of Chaos in Ferromagnetic Resonance
    Autorzy:
    Krawiecki, A.
    Sukiennicki, A.
    Powiązania:
    https://bibliotekanauki.pl/articles/1933554.pdf
    Data publikacji:
    1995-08
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    75.30.Ds
    05.45.+b
    76.50.+g
    Opis:
    Some non-trivial phenomena in chaos in ferromagnetic resonance above the first-order Suhl instability threshold are obtained numerically from a simple model of three interacting modes. They include sudden changes of the correlation dimension of the attractor and the largest Lyapunov exponent with the rise of the rf field amplitude. Numerical evidence is provided that these effects may result from the on-off intermittency in the system of interacting modes. These results are qualitatively similar to the experimental ones, known from the literature, obtained for in-plane magnetized thin films.
    Źródło:
    Acta Physica Polonica A; 1995, 88, 2; 269-281
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Nonlinear Dynamics of Interstitial Atom
    Autorzy:
    Kozarzewski, B.
    Powiązania:
    https://bibliotekanauki.pl/articles/1945690.pdf
    Data publikacji:
    1996-09
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    05.45.4b
    Opis:
    Interstitial impurity atom in an sc lattice driven by lattice vibrations is considered. The equation of motion derived is suitable for the study of an oscillator driven by modulated longitudinal wave and deterministic diffusion as well.
    Źródło:
    Acta Physica Polonica A; 1996, 90, 3; 499-507
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Simulations of Noise-Free Stochastic Resonance in Spin-Wave Chaos
    Autorzy:
    Krawiecki, A.
    Reibold, E.
    Benner, H.
    Sukiennicki, A.
    Powiązania:
    https://bibliotekanauki.pl/articles/2013991.pdf
    Data publikacji:
    2000-05
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    76.50.+g
    75.30.Ds
    05.45.+b
    05.40.+j
    Opis:
    Numerical simulations of noise-free stochastic resonance and aperiodic stochastic resonance in chaotic ferromagnetic resonance are presented. The model, based on three-magnon interactions between the externally excited uniform mode and pairs of spin waves, shows on-off intermittency. The rf magnetic field amplitude is slowly modulated by a small periodic or aperiodic signal, and the output signal, which reflects the occurrence of laminar phases and bursts in the time series of spin-wave amplitudes, is analyzed. On variation of the dc magnetic field the signal-to-noise ratio of the output signal and the correlation function between modulation and output signal pass a maximum, which indicates the occurrence of periodic and aperiodic stochastic resonance, respectively. The role of thermal magnon excitations in the occurrence of this maximum is clarified. The results are compared with experimental findings obtained in other types of intermittency.
    Źródło:
    Acta Physica Polonica A; 2000, 97, 5; 975-978
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Resonant Tunnelling Studies of Chaos in Quantised Systems
    Autorzy:
    Eaves, L.
    Fromhold, T. M.
    Wilkinson, P. P.
    Sheard, F. W.
    Powiązania:
    https://bibliotekanauki.pl/articles/1967958.pdf
    Data publikacji:
    1997-10
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    72.20.My
    73.40.Gk
    85.30.Mn
    05.45.+b
    Opis:
    This paper gives a brief introductory overview of quantum chaology, with particular reference to recent experimental work involving the use of semiconductor heterostructures. In the presence of a tilted magnetic field, a double-barrier resonant-tunnelling device incorporating a quantum well produces a chaotic stadium for electron motion. The basic properties of this system are described. It is shown how resonant magnetotunnelling spectroscopy provides firm experimental evidence for the effect of scarred wave functions on a physically-measurable property, in this case the measured current-voltage characteristics of the device. The paper concludes with some speculations concerning for the development of this field.
    Źródło:
    Acta Physica Polonica A; 1997, 92, 4; 609-619
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Asymmetry Induced Localization
    Autorzy:
    Kohler, H.
    Powiązania:
    https://bibliotekanauki.pl/articles/1399044.pdf
    Data publikacji:
    2013-12
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    05.30.-d
    03.65.Yz
    05.45.Mt
    73.23.-b
    Opis:
    We consider a two-level system, which couples via non-commuting operators to two independent oscillator baths. When the coupling is symmetric, the renormalized hopping matrix element is finite even for infinitely strong coupling strength. The two-level system is in a delocalized phase. For finite coupling strength a localization transition occurs for a critical asymmetry angle, which separates the localized from the delocalized phase. Using the method of flow equations we are able to monitor real time dynamics.
    Źródło:
    Acta Physica Polonica A; 2013, 124, 6; 1053-1059
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Numerical Analysis of Modified Kaldor-Kalecki Model with Couplings and Delays
    Autorzy:
    Jackowska-Zduniak, B.
    Orłowski, A.
    Powiązania:
    https://bibliotekanauki.pl/articles/1398889.pdf
    Data publikacji:
    2016-05
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    89.65.Gh
    88.05.Lg
    05.45.-a
    02.60.Lj
    05.45.Xt
    Opis:
    Modified Kaldor-Kalecki-type model of business cycles with delays are considered. Unidirectional and bidirectional couplings are introduced to investigate relationships between three "global" markets and two "local" markets. Selected results of an extensive numerical analysis are presented.
    Źródło:
    Acta Physica Polonica A; 2016, 129, 5; 1008-1010
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Numerical Analysis of Two Coupled Kaldor-Kalecki Models with Delay
    Autorzy:
    Jackowska-Zduniak, B.
    Grzybowska, U.
    Orłowski, A.
    Powiązania:
    https://bibliotekanauki.pl/articles/1388508.pdf
    Data publikacji:
    2015-03
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    89.65.Gh
    88.05.Lg
    05.45.-a
    02.60.Lj
    05.45.Xt
    Opis:
    This paper is concerned with two coupled Kaldor-Kalecki models of business cycles with delays in both the gross product and the capital stock. We consider two types of investment functions that lead to different behavior of the system. We introduce the model with unidirectional coupling to investigate the influence of a global economy (like the European Union) on a local economy (like Poland). We present detailed results of numerical analysis.
    Źródło:
    Acta Physica Polonica A; 2015, 127, 3A; A-70-A-74
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Fidelity Decay in Chaotical and Random Systems
    Autorzy:
    Kohler, H.
    Powiązania:
    https://bibliotekanauki.pl/articles/1492437.pdf
    Data publikacji:
    2011-12
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    05.30.-d
    03.65.Yz
    05.45.Mt
    73.23.-b
    Opis:
    Fidelity is the overlap of wave functions with the same initial state propagated in time by slightly different Hamiltonians. Its behavior depends crucially on the choice of the initial wave function state. We review two cases: first, the initial state is random. In this case a simple analytic relation with parametric spectral correlations can be established. The latter quantity is completely determined by the spectral data and can therefore be measured, without knowledge about the wave function. Second, the initial state is an eigenstate of the unperturbed system. In this case fidelity is identical to the survival probability. We find unexpected features like revival and non-ergodicity. In this case fluctuations around the mean are large and the full fidelity distribution becomes a non-trivial function. The full fidelity distribution can be calculated in the long time limit and for small perturbations.
    Źródło:
    Acta Physica Polonica A; 2011, 120, 6A; A-119-A-126
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Analysis of Missing Level Statistics for Microwave Networks Simulating Quantum Chaotic Graphs Without Time Reversal Symmetry - the Case of Randomly Lost Resonances
    Autorzy:
    Ławniczak, M.
    Białous, M.
    Yunko, V.
    Bauch, S.
    Dietz, B.
    Sirko, L.
    Powiązania:
    https://bibliotekanauki.pl/articles/1030011.pdf
    Data publikacji:
    2017-12
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    05.40.-a
    05.45.Mt
    05.45.Tp
    03.65.Sq
    Opis:
    We present experimental and numerical studies for level statistics in incomplete spectra obtained with microwave networks simulating quantum chaotic graphs with broken time reversal symmetry. We demonstrate that, if resonance frequencies are randomly removed from the spectra, the experimental results for the nearest-neighbor spacing distribution, the spectral rigidity and the average power spectrum are in good agreement with theoretical predictions for incomplete sequences of levels of systems with broken time reversal symmetry.
    Źródło:
    Acta Physica Polonica A; 2017, 132, 6; 1672-1676
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Embedded Soliton Solutions: A Variational Study
    Autorzy:
    Pal, D.
    Golam Ali, Sk.
    Talukdar, B.
    Powiązania:
    https://bibliotekanauki.pl/articles/1813496.pdf
    Data publikacji:
    2008-02
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    42.65.Tg
    05.45.Yv
    Opis:
    We use a variational method to construct soliton solutions for systems characterized by opposing dispersion and competing nonlinearities at fundamental and second harmonics. We show that both ordinary and embedded solitons tend to gain energy when the second harmonic field becomes weaker than the first harmonic field.
    Źródło:
    Acta Physica Polonica A; 2008, 113, 2; 707-712
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    On the Zipf Strategy for Short-Term Investments in WIG20 Futures
    Autorzy:
    Bieda, B.
    Chodorowski, P.
    Grech, D.
    Powiązania:
    https://bibliotekanauki.pl/articles/1409028.pdf
    Data publikacji:
    2012-02
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    05.45.Tp
    89.75.Da
    05.40.-a
    89.65.Gh
    Opis:
    We apply the Zipf power law to financial time series of WIG20 index daily changes (open-close values). Thanks to the mapping of time series signal into the sequence of 2k+1 'spin-like' states, where k=0, 1/2, 1, 3/2, ..., we are able to describe any time series increments, with almost arbitrary accuracy, as the one of such 'spin-like' states. This procedure leads in the simplest non-trivial case (k = 1/2) to the binary data projection. More sophisticated projections are also possible and mentioned in the article. The introduced formalism allows then to use Zipf power law to describe the intrinsic structure of time series. The fast algorithm for this implementation was constructed by us within $\text{Matlab}^{TM}$ software. The method, called Zipf strategy, is then applied in the simplest case k = 1/2 to WIG 20 open and close daily data to make short-term predictions for forthcoming index changes. The results of forecast effectiveness are presented with respect to different time window sizes and partition divisions (word lengths in Zipf language). Finally, the various investment strategies improving return of investment (ROI) for WIG20 futures are proposed. We show that the Zipf strategy is the appropriate and very effective tool to make short-term predictions and therefore, to evaluate short-term investments on the basis of historical stock index data. Our findings support also the existence of long memory in financial data, exceeding the known in the literature 3 days span limit.
    Źródło:
    Acta Physica Polonica A; 2012, 121, 2B; B-7-B-10
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Path Dependence in Neoclassical Economic Growth Theory
    Autorzy:
    Jakimowicz, A.
    Powiązania:
    https://bibliotekanauki.pl/articles/1388527.pdf
    Data publikacji:
    2015-03
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    89.65.Gh
    89.75.-k
    05.45.-a
    07.89.+b
    Opis:
    Path dependence is a key feature of complex economic systems. It implies that history matters in the long-term evolution of markets and economies. Path dependence can be viewed as the dynamic version of positive feedback effects. This paper focuses on the nonlinear neoclassical economic growth model with the Cobb-Douglas production function, which accounts for problems related to pollutant emissions. It was found that only selected initial forms have a chance to develop. Present states depend on past states, even though the historical circumstances that had affected the past states may no longer be relevant. The choice among different histories may be a stochastic process. The understanding of economic growth suggested in this study stands in opposition to the neoclassical tradition based on equilibrium states or paths independent of the system's history. In contemporary economics, the idea of path dependence is most often used in studies on the high-tech industry, where the researchers are focused on such phenomena as innovation processes, monopolization, or the causes of ineffective technical solutions. The analysis of historical conditions is almost entirely carried out with the use of qualitative methods, since the subject of the research is non-formalized. In addition, the theoretical basis for conducting relevant empirical research is still missing. As a result of the development of complexity economics in recent years, numerous dynamic features of complex economic systems can be examined with the application of quantitative methods which, in effect, strengthens the bonds between theory and practice. Rare exceptions include path dependence relations. The aim of this article is to fill this gap and to create a theoretical basis for quantitative research on historical conditions in economics. This is a necessary condition for undertaking empirical research. The theoretical search started with the Keynesian model of the Samuelson-Hicks trade cycle, to demonstrate that conventional economics completely omits the most interesting path-dependence cases. It turns out that only the neoclassical model of economic growth, taking into account two power laws, provides appropriate dynamic characteristics for a full description of path dependence relations. Therefore, appropriate theoretical bases can be provided only by complexity economics. It may seem that, in this work, the dependence on history is restricted to two successive time steps in the case of the Samuelson-Hicks model and a single step in the neoclassical model of economic growth by Day. However, it examines an ordered path dependence, where events are chronologically ordered and the impact of earlier events on the later ones occurs through intermediary events. It should be remembered that events are constantly affected by environmental stimuli that are reflected not only in initial conditions, but also in the values of the parameters for all periods. Thus, it is not a case of short-term memory.
    Źródło:
    Acta Physica Polonica A; 2015, 127, 3A; A-86-A-94
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    B-Spline Solution and the Chaotic Dynamics of Troeschs Problem
    Autorzy:
    Caglar, H.
    Caglar, N.
    Ozer, M.
    Powiązania:
    https://bibliotekanauki.pl/articles/1291812.pdf
    Data publikacji:
    2014-02
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    05.45.Pq
    02.60.-x
    02.60.Lj
    Opis:
    A B-spline method is presented for solving the Troesch problem. The numerical approximations to the solution are calculated and then their behavior is studied and commenced. The chaotic dynamics exhibited by the solutions of Troesch's problem as they were derived by the decomposition method approximation are examined and an approximate critical value for the parameter λ is introduced also in this study. For the parameter value slightly less than λ ≈ 2.2, the solutions begin to show successive bifurcations, finally entering chaotic regimes at higher λ values. The effectiveness and accuracy of the B-spline method is verified for different values of the parameter, below its critical value, where the first bifurcation occurs.
    Źródło:
    Acta Physica Polonica A; 2014, 125, 2; 554-559
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Design of a Single Line Half Duplex Protocol for Mechanical Rotary Table Systems
    Autorzy:
    Ozkan, S.
    Atali, G.
    Boru, B.
    Karayel, D.
    Powiązania:
    https://bibliotekanauki.pl/articles/1031133.pdf
    Data publikacji:
    2017-09
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    07.05.Hd
    07.50.-e
    89.70.Hj
    07.05.Dz
    45.80.+r
    Opis:
    In this study, a new communication protocol, which addresses the rotary table, has been designed. Developed system works over a single line and is using slip rings. The designed communication protocol ensures the half duplex communication for multiple stations over a single cable. During the protocol design, media access methods, coding techniques and multi-node synchronization techniques were examined. These techniques have been adapted, updated and combined for the study, during the formation of the communication protocol. The designed protocol was tested and verified in the simulation environment with original software, on the microcontrollers. The protocol is aimed to be open source, flexible, easily applicable and a new solution for the distributed control problems in the field of automation and for the rotary table systems in particular.
    Źródło:
    Acta Physica Polonica A; 2017, 132, 3; 749-752
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Matter-Wave Bright Solitons of $\text{}^7Li$ Gas in an Expulsive Potential
    Autorzy:
    Golam Ali, Sk.
    Talukdar, B.
    Roy, S.
    Powiązania:
    https://bibliotekanauki.pl/articles/1814020.pdf
    Data publikacji:
    2007-12
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    03.75.Fi
    05.45.Yv
    Opis:
    A Lagrangian based method is used to derive an analytical model for studying the dynamics of matter-wave bright soliton created in a harmonic potential which is attractive in the transverse direction and expulsive in the longitudinal direction. By means of sech trial functions and a Ritz optimization procedure, evolution equations are constructed for width, amplitude and nonlinear frequency chirp of the propagating soliton of the atomic condensate. Our equation for the width is an exact agreement with that of Carr and Castin, obtained by more detailed analysis. In agreement with the experiment of Paris group, the expulsive potential is found to cause the soliton to explode for N|$a_s$|=0.98, N being the number of atoms in the condensate and $a_s$ -- the scattering length of the atom-atom interaction.
    Źródło:
    Acta Physica Polonica A; 2007, 112, 6; 1165-1170
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Substantially Higher Corrosion Resistance in AE42 Magnesium Alloy through Corrosion Layer Stabilization by ECAP Treatment
    Autorzy:
    Minárik, P.
    Král, R.
    Hadzima, B.
    Powiązania:
    https://bibliotekanauki.pl/articles/1419053.pdf
    Data publikacji:
    2012-09
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    81.05.-t
    82.45.Bb
    Opis:
    The corrosion properties of magnesium alloy AE42, just extruded and with posterior eight passes through equal channel angular pressing after extrusion, were investigated in 0.1 M NaCl by electrochemical impedance spectroscopy. The obtained samples were compared using scanning electron microscopy micrographs of the corrosion layers created on the surface of the specimens. The background of the substantial higher corrosion resistance of the samples after equal channel angular pressing treatment was found to be the much thicker and stable corrosion layer and smaller separating fragments in comparison with the just extruded samples. The lowering of the grain size by severe plastic deformation, especially by the equal channel angular pressing treatment was found to be also responsible for the enhancement of the corrosion resistance in AE42 class of magnesium alloys.
    Źródło:
    Acta Physica Polonica A; 2012, 122, 3; 614-617
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Nanodevice for High Precision Readout of Electron Spin
    Autorzy:
    Szumniak, P.
    Bednarek, S.
    Szafran, B.
    Grynkiewicz, P.
    Powiązania:
    https://bibliotekanauki.pl/articles/2048078.pdf
    Data publikacji:
    2011-05
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    73.21.La
    73.63.Nm
    03.67.Lx
    05.45.Yv
    Opis:
    In this paper we propose and simulate operation of a nanodevice, which enables the electron spin accumulation and very precise read-out of its final value. We exploit the dependence of the electron trajectory on its spin state due to the spin-orbit coupling in order to distinguish between different spin orientations.
    Źródło:
    Acta Physica Polonica A; 2011, 119, 5; 651-653
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Structure and magnetic properties of Fe-B-Si-Zr metallic glasses
    Autorzy:
    Babilas, R.
    Radoń, A.
    Gębara, P.
    Powiązania:
    https://bibliotekanauki.pl/articles/1054824.pdf
    Data publikacji:
    2017-04
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    33.45.+x
    61.05.cp
    64.70.pe
    75.50.Kj
    Opis:
    Fe-based amorphous alloys were characterized by X-ray diffraction, transmission Mössbauer spectroscopy and vibrating sample magnetometry. The studies were performed on (Fe_{0.75}B_{0.15}Si_{0.1})_{100-x}Zr_{x} (x=0, 1, 3) metallic glasses in the form of ribbons. The glassy samples were prepared by the "melt spinning" technique in argon protective atmosphere. The XRD patterns show the broad diffraction halo that is typical for amorphous Fe-based alloys. The Mössbauer spectroscopy allows to study the local environments of the Fe atoms in the glassy state, showing the changes in the amorphous structure due to the changing of Zr addition. From hysteresis loops obtained from vibrating sample magnetometry measurements, coercive force and saturation magnetization were determined versus different Zr content. The obtained magnetic properties allow to classify the studied amorphous alloys in as-cast state as soft magnetic materials.
    Źródło:
    Acta Physica Polonica A; 2017, 131, 4; 726-728
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Evolution of Corrosion Resistance in the LAE442 Magnesium Alloy Processed by ECAP
    Autorzy:
    Minárik, P.
    Král, R.
    Janeček, M.
    Chmelík, F.
    Hadzima, B.
    Powiązania:
    https://bibliotekanauki.pl/articles/1402153.pdf
    Data publikacji:
    2015-10
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    81.05.-t
    82.45.Bb
    Opis:
    The influence of processing by equal channel angular pressing on the corrosion resistance was investigated in the extruded LAE442 magnesium alloy by the linear polarization method. Continuous increase of the corrosion resistance with the increasing number of passes was measured. The polarization resistance of the 12P sample was substantially higher as compared to the extruded state. The results were discussed in terms of the corrosion layers formed on the surface after seven days of immersion. It was concluded that the substantial increase of polarization resistance was caused by the combined effect of grain refinement and aluminum and lithium oxides formation within the corrosion layer.
    Źródło:
    Acta Physica Polonica A; 2015, 128, 4; 772-774
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Statistics of Conductance and Shot-Noise Power for Chaotic Cavities
    Autorzy:
    Sommers, H.-J.
    Wieczorek, W.
    Savin, D. V.
    Powiązania:
    https://bibliotekanauki.pl/articles/2047832.pdf
    Data publikacji:
    2007-10
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    73.23.-b
    73.50.Td
    05.45.Mt
    73.63.Kv
    Opis:
    We report on an analytical study of the statistics of conductance, g, and shot-noise power, p, for a chaotic cavity with arbitrary numbers N$\text{}_{1,2}$ of channels in two leads and symmetry parameterβ = 1, 2, 4. With the theory of Selberg's integral the first four cumulants of g and first two cumulants of p are calculated explicitly. We give analytical expressions for the conductance and shot-noise distributions and determine their exact asymptotics near the edges up to linear order in distances from the edges. For 0 < g < 1 a power law for the conductance distribution is exact. All results are also consistent with numerical simulations.
    Źródło:
    Acta Physica Polonica A; 2007, 112, 4; 691-697
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Effect of Microstructure on the Corrosion Resistance of the AE42 Magnesium Alloy Processed by Rotary Swaging
    Autorzy:
    Minárik, P.
    Zemková, M.
    Král, R.
    Mhaede, M.
    Wagner, L.
    Hadzima, B.
    Powiązania:
    https://bibliotekanauki.pl/articles/1402163.pdf
    Data publikacji:
    2015-10
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    81.05.-t
    82.45.Bb
    Opis:
    Microstructure and corrosion resistance of the AE42 commercial alloy processed by extrusion and rotary swaging were investigated. Microstructure characterization showed an increasing volume fraction of the refined grains with increasing stage of swaging processing. However, their presence was limited solely to the peripheral ring of ≈1 mm in all studied conditions of swaged material. Corrosion resistance investigation showed continuous decrease of polarization resistance that was attributed to the grain refinement and insufficient homogenization of the alloying elements during the swaging process.
    Źródło:
    Acta Physica Polonica A; 2015, 128, 4; 805-807
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Chaotic Time-Reversed Acoustics: Sensitivity οf the Loschmidt Echo to Perturbations
    Autorzy:
    Taddese, B.
    Johnson, M.
    Hart, J.
    Antonsen, T.
    Ott, E.
    Anlage, S.
    Powiązania:
    https://bibliotekanauki.pl/articles/1585110.pdf
    Data publikacji:
    2009-11
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    03.55.Kk
    05.45.Mt
    43.58.+z
    43.60.+d
    Opis:
    We experimentally demonstrate a new acoustic sensor based on the concept of quantum mechanical scattering fidelity and the Loschmidt echo applied to classical acoustic waves in air. The sensor employs a one-recording-channel time-reversal mirror that exploits spatial reciprocity to sensitively measure the classical analog of the scattering fidelity of an enclosed region. The experiments are carried out in a stairwell using a simple speaker and microphone. The input is a 7.0 kHz signal that is amplitude modulated with a 1 ms long pulse. We examine the sensitivity of the time-reversed reconstructed pulse to phase noise, long term drift, and to typical perturbations caused by the rotation of an object in the scattering environment.
    Źródło:
    Acta Physica Polonica A; 2009, 116, 5; 729-732
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Wear Behavior of Surface Treated X45MoCrV5-3-1 Tool Steel at Room and Elevated Temperatures
    Autorzy:
    Aktaş, G.
    Polat, Ş.
    Atapek, Ş.
    Powiązania:
    https://bibliotekanauki.pl/articles/1401330.pdf
    Data publikacji:
    2015-04
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    81.05.Bx
    81.65.-b
    81.40.Pq
    81.70.-q
    Opis:
    The aim of this study is to compare the wear behavior of X45MoCrV5-3-1 tool steel, used as die material in aluminum extrusion, after single treatment (CrN coating) and duplex treatment (nitriding and CrN coating). Gas nitriding and physical vapor deposition were used as processing techniques and wear tests were carried out at both room and elevated temperatures. A "ball-on-disc" type tribometer was used for room temperature tests, utilizing Al₂O₃ ball as counterpart. In order to simulate the wear conditions during extrusion, hot wear tests were carried out at 450°C using "block-on-cylinder" type tribometer against AA 6080 material. Worn surfaces were studied by microscopy to reveal the wear characteristics of treated steels. It was found that (i) duplex treated steel, having higher friction coefficient at room and elevated temperature, had higher wear resistance, (ii) at room temperature single treated steel exhibited higher volume loss than the duplex treated one, (iii) at elevated temperature duplex treated steel revealed a stable coating layer, whereas micro cracks were observed on the surface of the single treated steel.
    Źródło:
    Acta Physica Polonica A; 2015, 127, 4; 1221-1224
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Investigation of the Effects of Erosion Test Parameters on the Particle Impengement Velocity by Using CFD Analysis
    Autorzy:
    Önen, B.
    Yıldıran, Y.
    Avcu, E.
    Çınar, A.
    Powiązania:
    https://bibliotekanauki.pl/articles/1193091.pdf
    Data publikacji:
    2015-04
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    45.50.Dd
    47.60.Kz
    07.05.Tp
    47.80.Jk
    Opis:
    Particle impingement velocity is one of the most important parameters in solid particle erosion. Particle impingement velocity depends on erosion test parameters such as particle acceleration pressure, erodent particle size and standoff distance. Over the past decades many experimental studies have been conducted to examine the effects of these parameters on the particle impingement velocity. In this study, the effects of particle acceleration pressure, erodent particle size and standoff distance on the particle impingement velocity have been investigated by using a computational fluid dynamics (CFD) program, FLUENT. In order to achieve these goals solid particle erosion tests are simulated under various test parameters and the effects of these parameters are examined in detail. The effect of particle velocity on the flow field is characterized with method geometrics. Two-dimensional plane symmetrical models are utilized to reduce the computation time. Plots of gas pressure and particle velocity contours at the XY symmetrical plane from nozzle inlet to substrate were given. CFD analysis showed that all erosion test parameters have dramatically affected particle impingement velocity. Particle impingement velocity was increased with increases in acceleration pressure while it was decreased with increases in both erodent particle size and standoff distance.
    Źródło:
    Acta Physica Polonica A; 2015, 127, 4; 1225-1229
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Exact Solutions and Light Bullet Soliton Solutions of the Two-Dimensional Generalized Nonlinear Schrödinger Equation with Distributed Coefficients
    Autorzy:
    Huang, W.
    Mu, C.
    Xu, Y.
    Ding, B.
    Powiązania:
    https://bibliotekanauki.pl/articles/1399167.pdf
    Data publikacji:
    2013-10
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    02.30.Jr
    03.65.Ge
    05.45.Yv
    42.65.Tg
    Opis:
    A generalized G'/G-expansion method is extended to construct exact solutions to the two-dimensional generalized nonlinear Schrödinger equation with distributed coefficients. Hyperbolic function solution, trigonometric function solution and rational exact solution with parameters are obtained. Selecting parameters and parameter functions properly, novel light bullet soliton solutions with or without the chirp are presented.
    Źródło:
    Acta Physica Polonica A; 2013, 124, 4; 622-625
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Luminescence of Lanthanides from Xerogels Embedded in Mesoporous Matrices
    Autorzy:
    Gaponenko, N.
    Powiązania:
    https://bibliotekanauki.pl/articles/1814047.pdf
    Data publikacji:
    2007-11
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    81.20.Fw
    83.80.Jx
    81.05.Rm
    78.55.Mb
    61.43.Gt
    82.45.Cc
    42.70.Qs
    78.55.Ap
    78.60.-b
    Opis:
    The report summarizes peculiarities of synthesis and luminescence properties of porous silicon, porous anodic alumina and artificial opals with the inclusions of sol-gel derived oxides (xerogels), doped with Er, Tb, and Eu. Origin of strong luminescence of lanthanides from xerogels in mesoporous matrices is discussed.
    Źródło:
    Acta Physica Polonica A; 2007, 112, 5; 737-749
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Physico-Chemical and Biological Properties of Arsenic Sulfide ($As_{55}S_{45}$) Nanosuspension Prepared by Milling
    Autorzy:
    Bujňáková, Z.
    Shpotyuk, O.
    Sedlák, J.
    Pastorek, M.
    Turianicová, E.
    Baláž, P.
    Ingram, A.
    Powiązania:
    https://bibliotekanauki.pl/articles/1375164.pdf
    Data publikacji:
    2014-10
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    81.20.Wk
    81.05.Kf
    81.07.-b
    Opis:
    Nanosuspension based on melt-quenched arsenic sulfide of nominal $As_{55}S_{45}$ composition was prepared by nanomilling and tested as potential anticancer drug. Polyvinylpyrrolidone was used as steric stabilizer and inhibitor of agglomeration. Individual nanoparticles had average size of 192 nm (determined by photon cross-correlation spectroscopy) and had several times better dissolution ability in comparison with bulk $As_{55}S_{45}$. Effect of nanomilling is shown to be associated with formation of arsenic sulfide crystalline nanoparticles and free-volume entities located at the interface between nanoparticles and surrounding matrix as it follows from positron annihilation measurements. Cytotoxicity tests were performed using human melanoma cell line Bowes and confirmed high toxicity of the studied nanosuspension.
    Źródło:
    Acta Physica Polonica A; 2014, 126, 4; 902-906
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Magnetic Properties and Structure after Crystallization of $Fe_{80-x}B_{20}Nb_{x}$ (x=4, 6, 10) Metallic Glasses
    Autorzy:
    Nowosielski, R.
    Kądziołka-Gaweł, M.
    Gębara, P.
    Szyba, D.
    Babilas, R.
    Powiązania:
    https://bibliotekanauki.pl/articles/1398320.pdf
    Data publikacji:
    2017-05
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    33.45.+x
    61.05.cp
    64.70.pe
    75.50.Kj
    Opis:
    The ferromagnetic Fe-based amorphous alloys were studied due to properties for soft magnetic applications. Depending on different Nb addition, the formation of crystalline phases after annealing of amorphous $Fe_{80-x}B_{20}Nb_{x}$ (x = 4,6,10) alloys was studied. The crystallization products as well as the phase structure were determined using the Mössbauer spectrometry combined with differential scanning calorimetry and magnetic measurements. The addition of Nb caused a shift of crystallization process towards higher temperatures and induced changes in coercive force and decreased the saturation magnetization. It was found that Nb addition changed the crystallization process from single crystallization for Fe₇₆B₂₀Nb₄ alloy to binary crystallization in the Fe₇₄B₂₀Nb₆ and Fe₇₀B₂₀Nb₁₀ glasses. The annealing process at the onset crystallization temperature induced complex phase formation including the α-Fe, Fe₃B, and Fe₂B phases for alloys x=4, 6.
    Źródło:
    Acta Physica Polonica A; 2017, 131, 5; 1212-1216
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Interrelation of Microstructure and Corrosion Resistance in Biodegradable Magnesium Alloys with Aluminum, Lithium and Rare Earth Additions
    Autorzy:
    Minárik, P.
    Landa, M.
    Lesná, I.
    Zemková, M.
    Jablonská, E.
    Hadzima, B.
    Janeček, M.
    Král, R.
    Powiązania:
    https://bibliotekanauki.pl/articles/1402061.pdf
    Data publikacji:
    2015-10
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    81.05.-t
    82.45.Bb
    87.85.J-
    43.40.Le
    Opis:
    The influence of equal channel angular pressing and rotary swaging on the microstructure and corrosion resistance was investigated in three magnesium alloys with the addition of aluminum, lithium and rare earth elements - AE21, AE42 and LAE442. The processing resulted in grain refinement in all cases; nevertheless, the effect on the corrosion resistance was ambiguous. A continuous increase of the polarization resistance during the gradual equal channel angular pressing was observed in the AE42 and LAE442 alloys, whereas there was almost no effect in the AE21 alloy. The rotary swaging of AE42 resulted in a decrease of polarization resistance. The increase of polarization resistance in the alloys with the higher concentration of alloying elements was caused by the combined effect of grain refinement and better dispersion of particles in the matrix thanks to shear deformation during equal channel angular pressing. In the AE42 alloy, the increase of the corrosion resistance after equal channel angular pressing was also proven by chemical analysis of the solution and acoustic emission detection. This beneficial effect was not observed when the concentration of alloying elements was lower or when the deformation mode was different from shearing.
    Źródło:
    Acta Physica Polonica A; 2015, 128, 4; 491-496
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Impedance and Scattering Variance Ratios of Complicated Wave Scattering Systems in the Low Loss Regime
    Autorzy:
    Yeh, J.
    Drikas, Z.
    Gil Gil, J.
    Hong, S.
    Taddese, B.
    Ott, E.
    Antonsen, T.
    Andreadis, T.
    Anlage, S.
    Powiązania:
    https://bibliotekanauki.pl/articles/1399042.pdf
    Data publikacji:
    2013-12
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    05.45.Mt
    24.60.-k
    42.25.Dd
    78.20.Bh
    Opis:
    Random matrix theory successfully predicts universal statistical properties of complicated wave scattering systems in the semiclassical limit, while the random coupling model offers a complete statistical model with a simple additive formula in terms of impedance to combine the predictions of random matrix theory and nonuniversal system-specific features. The statistics of measured wave properties generally have nonuniversal features. However, ratios of the variances of elements of the impedance matrix are predicted to be independent of such nonuniversal features and thus should be universal functions of the overall system loss. In contrast with impedance variance ratios, scattering variance ratios depend on nonuniversal features unless the system is in the high loss regime. In this paper, we present numerical tests of the predicted universal impedance variance ratios and show that an insufficient sample size can lead to apparent deviation from the theory, particularly in the low loss regime. Experimental tests are carried out in three two-port microwave cavities with varied loss parameters, including a novel experimental system with a superconducting microwave billiard, to test the variance-ratio predictions in the low loss time-reversal-invariant regime. It is found that the experimental results agree with the theoretical predictions to the extent permitted by the finite sample size.
    Źródło:
    Acta Physica Polonica A; 2013, 124, 6; 1045-1052
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
      Wyświetlanie 1-54 z 54

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