Autor: Tóthová, V. - Katalog OPAC zbiorów

Skocz do pozycji: 1.

Tytuł:: Effect of Stochastic Dynamics on the Nuclear Magnetic Resonance in a Field Gradient
Autorzy:: Tóthová, J.
Lisý, V.
Powiązania:: https://bibliotekanauki.pl/articles/1032635.pdf
Data publikacji:: 2017-04
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 76.60.-k
76.60.Lz
05.40.-a
05.10.Gg
Opis:: In the present contribution, the attenuation function S(t) for an ensemble of spins in a magnetic-field gradient is calculated through an accumulation of the phase shifts in the rotating frame resulting from the changes of the particle displacements. The found S(t) is applicable for any kind of the stochastic motion of spins, including their non-Markovian dynamics with memory. Depending on the considered system, both the classical expressions valid for normal diffusion at long times and new formulae for the short-time Brownian motion can be obtained. Our method is also applicable to the NMR pulse sequences based on the refocusing principle. This is demonstrated by describing the spin echo experiment developed by Hahn.
Źródło:: Acta Physica Polonica A; 2017, 131, 4; 1111-1113
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

Artykuł

Skocz do pozycji: 2.

Tytuł:: Effect of Magnetic Field on the Fluctuations of Charged Oscillators in Viscoelastic Fluids
Autorzy:: Lisý, V.
Tóthová, J.
Powiązania:: https://bibliotekanauki.pl/articles/1202353.pdf
Data publikacji:: 2014-07
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 05.40.Jc
05.10.Gg
75.47.-m
82.70.Dd
Opis:: In the present work the generalized Langevin equation is solved for the motion of a charged Brownian oscillator in a magnetic field, when the thermal random force is exponentially correlated in the time. This model is consistent with the assumption that the medium has weakly viscoelastic properties. The velocity autocorrelation function, time-dependent diffusion coefficient and mean square displacement of the particle have been calculated. Our solutions generalize the previous results from the literature and are obtained in a way applicable to other problems of the Brownian motion with memory.
Źródło:: Acta Physica Polonica A; 2014, 126, 1; 413-414
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

Artykuł

Skocz do pozycji: 3.

Tytuł:: Hydrodynamic Memory in the Motion of Charged Brownian Particles across the Magnetic Field
Autorzy:: Tóthová, J.
Lisý, V.
Powiązania:: https://bibliotekanauki.pl/articles/1535477.pdf
Data publikacji:: 2010-11
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 05.40.Jc
05.10.Gg
75.47.-m
82.70.Dd
Opis:: An exact solution of the Langevin equation is given for a charged Brownian particle driven in an incompressible fluid by the magnetic field, taking into account the hydrodynamic aftereffect. The stochastic integro-differential Langevin equation is converted to a deterministic equation for the particle mean square displacement. We have found the mean square displacement and other time correlation functions describing the particle motion. For the motion along the field the known results from the theory of the hydrodynamic motion of a free Brownian particle are recovered. The correlation functions across the field contain at long times the familiar Einstein terms and additional algebraic tails. The longest-lived tail in the mean square displacement is proportional to $t^{1//2}$. At short times the motion is ballistic and independent of the magnetic field.
Źródło:: Acta Physica Polonica A; 2010, 118, 5; 1051-1053
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

Artykuł

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