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991.
Ronald Fisch 《Journal of statistical physics》2008,130(3):561-569
The ground state entropy of the 2D Ising spin glass with +1 and −1 bonds is studied for L×M square lattices with L≤M and p=0.5, where p is the fraction of negative bonds, using periodic and/or antiperiodic boundary conditions. From this we obtain the domain
wall entropy as a function of L and M. It is found that for domain walls which run in the short, L direction, there are finite-size scaling functions which depend on the ratio
, where d
S
=1.22±0.01. When M is larger than L, very different scaling forms are found for odd L and even L. For the zero-energy domain walls, which occur when L is even, the probability distribution of domain wall entropy becomes highly singular, and apparently multifractal, as
becomes large. 相似文献
992.
J. M. Vargas E. Lima Jr R. D. Zysler J. G. S. Duque E. De Biasi M. Knobel 《The European Physical Journal B - Condensed Matter and Complex Systems》2008,63(2):211-218
Size effect on the internal magnetic structure has been investigated on weakly interacting magnetite (Fe3O4) nanoparticles by ferromagnetic resonance experiments at 9.5 GHz as a function of temperature (4–300 K). A set of three samples
with mean particle size of 2.5 nm, 5.0 nm and 13.0 nm, respectively, were prepared by chemical route with narrow size distribution
(σ < 0.27). To minimize the dipolar interaction, the particles were dispersed in a liquid and a solid polymer matrix at ∼0.6%
in mass. By freezing the liquid suspension with an applied external field, a textured was obtained. Thus, both random and
textured suspensions were studied and compared. The ferromagnetic resonance experiments in zero-field-cooled and field-cooled
conditions were carried out to study the size effect on the effective anisotropy field. The dc magnetization measurements clearly show that the internal magnetic structure was strongly affected by the particle size. 相似文献
993.
Su Jung Noh 《Journal of magnetism and magnetic materials》2010,322(21):3601-3604
We report micromagnetic modeling results of current induced domain wall (DW) motion in magnetic devices with perpendicular magnetic anisotropy by solving the Landau-Lifschitz-Gilbert equation including adiabatic and non-adiabatic terms. A nanostripe model system with dimensions of 500 nm (L)×25 nm (W)×5 nm (H) was selected for calculating the DW motion and its width, as a function of various parameters such as non-adiabatic contribution, anisotropy constant (Ku), saturation magnetization (Ms), and temperature (T). The DW velocity was found to increase when the values of Ku and T were increased and the Ms value decreased. In addition, a reduction of the domain wall width could be achieved by increasing Ku and lowering Ms values regardless of the non-adiabatic constant value. 相似文献
994.
The properties of the asymptotic AdS3 space–times representing flat domain walls (DW's) solutions of the new massive 3D gravity with scalar matter are studied. Our analysis is based on first order BPS-like equations involving an appropriate superpotential. The Brown–York boundary stress-tensor is used for the calculation of DW's tensions as well as of the CFT2 central charges. The holographic renormalization group flows and the phase transitions in specific deformed CFT2 dual to 3D massive gravity model with quadratic superpotential are discussed. 相似文献
995.
Distance measures for dynamic citation networks 总被引:1,自引:0,他引:1
Michael J. Bommarito II Daniel Martin Katz Jonathan L. Zelner James H. Fowler 《Physica A》2010,389(19):4201-4208
Acyclic digraphs arise in many natural and artificial processes. Among the broader set, dynamic citation networks represent an important type of acyclic digraph. For example, the study of such networks includes the spread of ideas through academic citations, the spread of innovation through patent citations, and the development of precedent in common law systems. The specific dynamics that produce such acyclic digraphs not only differentiate them from other classes of graphs, but also provide guidance for the development of meaningful distance measures. In this article, we develop and apply our sink distance measure together with the single-linkage hierarchical clustering algorithm to both a two-dimensional directed preferential attachment model as well as empirical data drawn from the first quarter-century of decisions of the United States Supreme Court. Despite applying the simplest combination of distance measure and clustering algorithm, analysis reveals that more accurate and more interpretable clusterings are produced by this scheme. 相似文献
996.
QSPR study on GC relative retention time of organic pesticides on different chromatographic columns 总被引:1,自引:0,他引:1
In the present study, Lu index and distance-based atom type topological index (DAI) previously developed in our team, were introduced and combined with molecular electronegativity chi ep to characterize quantitative structure-property relationship of GC relative retention time (RRT) for several types of structurally diverse organic pesticides on the four kinds of chromatographic columns. Using multiple linear regression technique, four several-variable models are obtained with the estimations correlation coefficient (R(2)) being between 0.9655 and 0.9285, and the correlation coefficient (R(2)cv) in the leave-one-out cross-validation procedure are between 0.9560 and 0.9143, respectively. The results in this study indicate that the three topological indices Lu index, DAI, and molecular electronegativity chi ep can predict the gas chromatographic RRT of organic pesticides with diverse hetero-atoms. 相似文献
997.
系统综述了自19世纪开始且至今常用统计相关性的方法,例如Pearson和Spearman相关系数,CorGc和CovGc 相关性及距离相关性方法。重点介绍了2011年提出的MIC方法以及由此引发的毁誉参半的大量评述,旨在揭示这一热点领域研究面貌。该领域不仅受到统计学家的关注,而且受到了分析大样本和异质数据的应用研究领域的学者们的追捧,例如基因组生物学家和网络信息研究者。这些研究者期望在众多已有方法的理解和剖析中更恰当地付诸应用,并提出新的应用问题来推动新的分析方法的创造。 相似文献
998.
999.
The paper is devoted to the extension of the near-wall domain decomposition, earlier developed in some previous works by the authors, to modeling flat-plate boundary layers undergoing laminar-to-turbulent bypass transition. The steady-state wall boundary layers at high-intensity free-stream turbulence are studied on the basis of differential turbulence models with the use of non-overlapping domain decomposition. In the approach the near-wall resolution is replaced by the interface boundary conditions of Robin type. In contrast to the previous studies, the main attention is paid to the laminar–turbulent transitional regime. With the use of modified turbulence models we study an effect of free-stream parameters on the development of dynamic processes in the boundary layer including a transitional regime and fully developed turbulent flow. In addition, for the first time a full scale domain decomposition is realized via iterations between the inner and outer subregions until a convergence. The computational profiles of the velocity and intensity of the turbulence kinetic energy are compared with experimental data. A possible range of location of the near-wall interface boundary is found. 相似文献
1000.
Let M be a compact orientable 3-manifold with M connected. If V ∪S W is a Heegaard splitting of M with distance at least 6, then the -stabilization of V ∪S W along M is unstabilized. Hence M has at least two unstabilized Heegaard splittings with different genera. The basic tool is a result on disk complex given by Masur and Schleimer. 相似文献