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241.
A. Adanlété AdjanohR. Belhi J. VogelM. Ayadi K. Abdelmoula 《Journal of magnetism and magnetic materials》2011,323(5):504-508
Magnetization reversal in ultra-thin Au/Co/Au films deposited on single crystal silicon (1 0 0) was investigated using Kerr microscopy. In the considered ultra-thin Co films, with a thickness between 0.7 and 1 nm, the coercivity and magnetic anisotropy decrease with decrease in cobalt layer thickness and the magnetization reversal dynamics is dominated by disordered domain wall motion. An analysis of the observed magnetization reversal dynamics is proposed, starting from the Fatuzzo-Labrune model. We show that the relaxation curves of these samples are well described by a function obtained by a technical transformation of Fatuzzo-Labrune model in the regime dominated by domain wall motion. 相似文献
242.
By the method of change measures,the moderate deviations for the Bessel clock t 0 ds X(ν) s is studied,where(X(ν) t,t≥ 0) is a squared Bessel process with index ν0.The rate function can be given explicitly.Furthermore,the functional moderate deviations for the Bessel clock are obtained. 相似文献
243.
采用强化错误运动表象记忆法,对我校教职工男子排球队和男子羽毛球队进行训练,并与传统训练方法进行比较,结果表明:新的训练方法的各项动作技术指标明显高于传统训练方法的技术指标(P〈0.01).由此提示:强化错误运动表象记忆是一种能改善陈旧性运动技能的有效方法. 相似文献
244.
S. E. Mangioni H. S. Wio 《The European Physical Journal B - Condensed Matter and Complex Systems》2008,61(1):67-73
We analyze the effect of a colored non Gaussian noise on a model of
a random walker moving along a ratchet potential. Such a model was
motivated by the transport properties of motor proteins, like
kinesin and myosin. Previous studies have been realized assuming
white noises. However, for real situations, in general we could
expect that those noises be correlated and non Gaussian. Among other
aspects, in addition to a maximum in the current as the noise
intensity is varied, we have also found another optimal value of the
current when departing from Gaussian behavior. We show the relevant
effects that arise when departing from Gaussian behavior,
particularly related to current's enhancement, and discuss its
relevance for both biological and technological situations. 相似文献
245.
Niti Nipun Sharma 《Journal of nanoparticle research》2008,10(2):333-340
Emissive power per unit area of a blackbody has been modeled as a function of frequency using quantum electrodynamics, semi-classical
and classical approaches in the available literature. Present work extends the classical lumped-parameter systems model of
Brownian motion of nanoparticle to abstract an emissive power per unit area model for nanoparticle radiating at temperature
greater than absolute zero. The analytical model developed in present work has been based on synergism of local deformation
leading to local motion of nanoparticle due to photon impacts. The work suggests the hypothesis of a free parameter f′ characterizing the damping coefficient of resistive forces to local motion of nanoparticle and the manipulation of which
is possible to realize desired emissivity from nanoparticles. The model is validated with the well established Planck’s radiation
law. 相似文献
246.
F. Slanina 《The European Physical Journal B - Condensed Matter and Complex Systems》2008,61(2):225-240
Far-from-equilibrium models of interacting particles in one dimension
are used as a basis for modelling the stock-market
fluctuations. Particle types and their positions are interpreted as
buy and sel orders placed on a price axis in the order book. We
revisit some modifications of well-known models, starting with the
Bak-Paczuski-Shubik model. We look at the four decades old Stigler
model and investigate its variants. One of them is the simplified
version of the Genoa artificial market. The list of studied models is
completed by the models of Maslov and Daniels et al. Generically, in
all cases we
compare the return distribution, absolute return autocorrelation and
the value of the Hurst exponent. It turns out that none of the models
reproduces satisfactorily all the empirical data, but the most promising
candidates for further development are the Genoa artificial market and
the Maslov model with moderate order evaporation. 相似文献
247.
P. H. Chavanis 《The European Physical Journal B - Condensed Matter and Complex Systems》2008,62(2):179-208
We study a general class of nonlinear mean field
Fokker-Planck equations in relation with an effective generalized
thermodynamical (E.G.T.) formalism. We show that these equations describe
several physical systems such as: chemotaxis of bacterial
populations, Bose-Einstein condensation in the canonical ensemble,
porous media, generalized Cahn-Hilliard equations, Kuramoto model,
BMF model, Burgers equation, Smoluchowski-Poisson system for
self-gravitating Brownian particles, Debye-Hückel theory of
electrolytes, two-dimensional turbulence... In particular, we show
that nonlinear mean field Fokker-Planck equations can provide
generalized Keller-Segel models for the chemotaxis of
biological populations. As an example, we introduce a new model of
chemotaxis incorporating both effects of anomalous diffusion and
exclusion principle (volume filling). Therefore, the notion of
generalized thermodynamics can have applications for concrete
physical systems. We also consider nonlinear mean field
Fokker-Planck equations in phase space and show the passage from
the generalized Kramers equation to the generalized Smoluchowski
equation in a strong friction limit. Our formalism is simple and
illustrated by several explicit examples corresponding to Boltzmann,
Tsallis, Fermi-Dirac and Bose-Einstein entropies among others. 相似文献
248.
本文根据实测数据分析了单点系泊物体绕系泊点作360°回转的概率,统计了系泊船船向与风向的相关性。结果表明,在一般海域作360°回转的概率是很小的;船向与风向的相关系数为0.826,因此作者认为,引起360°回转的主要原因是风,实用上可以根据主风向的回转概率或风玫瑰图来推断单点系泊物体的回转概率。 相似文献
249.
把非圆齿轮运动学原理推广到非圆齿轮行星机构中、给出了非圆齿轮机构的位置函数和传动比函数的计算公式.并结合几种典型非圆齿轮行星机构分析了其作为间歇机构应用时的约束条件. 相似文献
250.