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1.
C. Brunhuber F. G. Mertens Y. Gaididei 《The European Physical Journal B - Condensed Matter and Complex Systems》2004,42(1):103-112
We study the motion of envelope solitons on anharmonic atomic chains in the presence of dissipation and thermal fluctuations. We consider the continuum limit of the discrete system and apply an adiabatic perturbation theory which yields a system of stochastic integro-differential equations for the collective variables of the ansatz for the perturbed envelope soliton. We derive the Fokker-Planck equation of this system and search for a statistically equivalent system of Langevin equations, which shares the same Fokker-Planck equation. We undertake an analytical analysis of the Langevin system and derive an expression for the variance of the soliton position Var[x
s
] which predicts a stronger than linear time dependence of Var[x
s
] (superdiffusion). We compare these results with simulations for the discrete system and find they agree well. We refer to recent studies where the diffusion of pulse solitons were found to exhibit a superdiffusive behaviour on longer time scales.Received: 28 June 2004, Published online: 26 November 2004PACS:
05.10.Gg Stochastic analysis methods - 05.45.Yv Solitons - 05.40.-a Fluctuation phenomena, random processes, noise, and Brownian motion - 05.50. + q Lattice theory and statistics 相似文献
2.
3.
Wagner F Gruber O Lackner K Murmann HD Speth E Becker G Bosch HS Brocken H Cattanei G Dorst D Eberhagen A Elsner A Erckmann V Fussmann G Gehre O Gernhardt J Gierke Gv Glock E Grieger G Grigull P Haas G Hacker H Hartfuss HJ Jäckel H Jaenicke R Janeschitz G Junker J Karger F Kasparek W Keilhacker M Kick M Klüber O Kornherr M Kroiss H Kuehner M Lenoci M Lisitano G Maassberg M Mahn C Marlier S Mayer HM McCormick K Meisel D Mertens V Müller ER Müller Müller G Niedermeyer H Ohlendorf W 《Physical review letters》1986,56(20):2187-2190
4.
K. Müller R. Henkelmann J. P. Biersack P. Mertens 《Journal of Radioanalytical and Nuclear Chemistry》1977,38(1-2):9-17
The isotopes3He,6Li,7Be and10B exhibit extremely large cross sections, between 1 and 48 kilobarn, for (n, p) or (n, α) reactions with thermal neutrons.
Together with now available extracted thermal neutron fluxes of 10( n·cm−2·sec−1 or more, these reactions present a highly sensitive method of detecting the mentioned light elements in any heavy matrix
material. Through the experimentally determined energy losses of the emitted protons or α-particles, also well resolved depth
profiles can be obtained, as demonstrated here for some relevant examples from semiconductor and fusion technology. 相似文献
5.
6.
7.
8.
M. Althoff W. Braunschweig F.J. Kirschfink H.-U. Martyn P. Rosskamp D. Schmitz H. Siebke W. Wallraff J. Eisenmann H.M. Fischer H. Hartmann A. Jocksch G. Knop H. Kolanoski H. Kück V. Mertens R. Wedemeyer G. Zobernig 《Physics letters. [Part B]》1984,149(6):524-532
We have determined the average lifetime of hadrons containing b quarks produced in e+e? annihilation to be . Our method uses charged decay products from both non-leptonic and semileptonic decay modes. 相似文献
9.
Frost RL Kristof J Horvath E Martens WN Kloprogge JT 《Journal of colloid and interface science》2002,251(2):350-359
Controlled rate thermal analysis (CRTA) allows the separation of adsorbed and intercalated hydrazine. CRTA displays the presence of three different types of hydrogen-bonded hydrazine in the intercalation complex: (a) The first is adsorbed loosely bonded on the kaolinite structure fully expanded by hydrazine-hydrate and liberated between approx 50 and 70 degrees C (b) The second intercalated hydrazine is lost between approx 70 and 85 degrees C. (c) The third type of intercalated-hydrazine molecule is lost in the 85-130 degrees C range. CRTA at 70 degrees C enables the removal of hydrazine-water and results in the partial collapse of the hydrazine-intercalated kaolinite structure to form a hydrazine-intercalated kaolinite. Removal of the adsorbed hydrazine enables the DRIFT spectra of the hydrazine-intercalated complex without any adsorbed hydrazine to be obtained. A band at 3626 cm(-1) attributed to the inner surface hydroxyls of kaolinite hydrogen bonded to hydrazine is observed. The intercalation of hydrazine-hydrate into kaolinite is complex and results from the different types of surface interactions of the hydrazine with the kaolinite surfaces. 相似文献
10.
Carper WR Wahlbeck PG Antony JH Mertens D Dölle A Wasserscheid P 《Analytical and bioanalytical chemistry》2004,378(6):1548-1554
The molecular structure and rotational motion of the ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIM][PF6]) were studied over a wide temperature range using the Bloembergen–Purcell–Pound 13C NMR spin–lattice relaxation method and NOE factors. Examination of the spin–lattice relaxation times (T
1) and the rates (R
1=1/T
1) of the 1-butyl-3-methylimidazolium cation reveals the relative motions of each carbon in the imidazolium cation. The rotational characteristics of the [BMIM] cation are supported by ab-initio molecular structures of [BMIM][PF6] using density functional theory (DFT) and Hartree–Fock (HF) methods. The ab-initio gas phase structures of [BMIM][PF6] indicate that the 1-butyl-3-methylimidazolium C2 hydrogen, the ring methyl group, and the butyl side-chain hydrogen atoms form hydrogen bonds with the hexafluorophosphate anion. 相似文献