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1.
K.?L.?YaoEmail author Q.?M.?Liu Z.?L.?Liu X.?W.?Liu G.?Y.?Sun 《The European Physical Journal B - Condensed Matter and Complex Systems》2003,35(3):365-370
We introduce a solid-on-solid growth process which evolves by random deposition of dimers, surface diffusion, and evaporation
of monomers from the edges of plateaus. It is shown that the model exhibits a robust transition from a smooth to a rough phase.
The roughening transition is driven by an absorbing phase transition at the bottom layer of the interface, which displays
the same type of critical behavior as the pair contact process with diffusion 2A↦3A, 2A↦.
Received 14 October 2002 Published online 14 February 2003
RID="a"
ID="a"e-mail: Haye.Hinrichsen@physik.uni-wuppertal.de 相似文献
2.
On social percolation and small world network 总被引:1,自引:0,他引:1
E. Ahmed H.A. Abdusalam 《The European Physical Journal B - Condensed Matter and Complex Systems》2000,16(3):569-571
The social percolation model is generalized to include the propagation of two mutually exclusive competing effects on a one-dimensional
ring and a two-dimensional square lattice. It is shown that the result depends significantly on which effect propagates first
i.e. it is a non-commutative phenomenon. Then the propagation of one effect is studied on a small network. It generalizes the
work of Moore and Newman of a disease spread to the case where the susceptibility of the population is random. Three variants
of the Domany-Kinzel model are given. One of them (delayed) does not have a chaotic region for some value of the delay weight.
Received 24 February 2000 相似文献
3.
Summary Diffusion of a fractal cluster of dimensiond
f
in a three-dimensional space is investigated. The diffusion process is assumed to be modelled by a standard parabolic diffusion
equation, although a more general case represented by the Fokker-Planck-Kolmogoroff equation is also introduced. The mean-square
displacement of the cluster mass centre is analysed and its anomalous behaviour is presented and critically discussed. The
results obtained can be applied to describe some effects which may occur during the diffusion-limited cluster-cluster aggregation
process, especially when the viscosity of the solvent is changed in time and/or a directed transport of clusters is present
in the system.
Paper presented at the I International Conference on Scaling Concepts and Complex Fluids, Copanello, Italy, July 4–8, 1994. 相似文献
4.
A. Saichev D. Sornette 《The European Physical Journal B - Condensed Matter and Complex Systems》2006,51(3):443-459
Several recent works point out that the crowd of small unobservable
earthquakes (with magnitudes below the detection threshold md) may
play a significant and perhaps dominant role in triggering future
seismicity. Using the ETAS branching model of triggered seismicity, we
apply the formalism of generating probability functions to investigate
how the statistical properties of observable earthquakes differ from the
statistics of all events. The ETAS (epidemic-type aftershock sequence)
model assumes that each earthquake can trigger other earthquakes
(“aftershocks”). An aftershock sequence results in this model from the
cascade of aftershocks of each past earthquake. The triggering
efficiency of earthquakes is assumed to vanish below a lower magnitude
limit m0, in order to ensure the convergence of the theory and may
reflect the physics of state-and-velocity frictional rupture. We show
that, to a good approximation, the statistical distribution of seismic
rates of events with magnitudes above md generated by an ETAS model
with branching ratio n is the same as that of events generated by
another ETAS model with effective parameter n(md). Our present
analysis thus confirms, for the full statistical (time-independent
or large time-window approximation)
properties, the results obtained previously by one of us and Werner,
based solely on the average seismic rates (the first-order moment of the
statistics). Our analysis also demonstrates that this correspondence is
not exact, as there are small corrections which can be systematically
calculated, in terms of additional contributions that can be mapped onto
a different branching model. We also show that this approximate correspondence
of the ETAS model onto itself obtained by changing m0 into md, and n into
n(md) holds only with respect to its statistical properties
and not for all its space-time properties. 相似文献
5.
H. Hinrichsen H.M. Koduvely 《The European Physical Journal B - Condensed Matter and Complex Systems》1998,5(2):257-264
The local persistence probability P
l
(t) that a site never becomes active up to time t, and the global persistence probability P
g
(t) that the deviation of the global density from its mean value does not change its sign up to time t are studied in a (1+1)-dimensional directed percolation process by Monte-Carlo simulations. At criticality, starting from
random initial conditions, P
l
(t) decays algebraically with the exponent . The value is found to be independent of the initial density and the microscopic details of the dynamics, suggesting is an universal exponent. The global persistence exponent is found to be equal or larger than . This contrasts with previously known cases where . It is shown that in the special case of directed-bond percolation, P
l
(t) can be related to a certain return probability of a directed percolation process with an active source (wet wall).
Received: 15 December 1997 / Revised: 6 April 1998 / Accepted: 29 May 1998 相似文献
6.
M.A. Jafarizadeh 《The European Physical Journal B - Condensed Matter and Complex Systems》1998,4(1):103-112
Using the symmetry of (
d
+1)-simplex fractals with decimation number b
=2, the current distribution has been determined. Then using the renormalization group technique, based on the independent Schur's
invariant polynomials of current distributions, the multifractal spectrum of even moments of current distributions has been
evaluated analytically up to order six for an arbitrary value of d. Also the scaling exponents of order 8 and order 10 have been calculated numerically up to d
=30.
Received: 19 November 1997 / Revised: 21 January 1998 / Accepted: 9 February 1998 相似文献
7.
A. Saichev D. Sornette 《The European Physical Journal B - Condensed Matter and Complex Systems》2006,49(3):377-401
We report an empirical determination of the
probability density functions Pdata(r) (and
its cumulative version)
of the number r of earthquakes in finite space-time windows
for the California catalog, over fixed spatial boxes 5 ×5 km2,
20 ×20 km2 and 50 ×50 km2
and time intervals
and 1000 days. The data can
be represented by asymptotic power law tails together with several
cross-overs. These observations are
explained by a simple stochastic branching process previously studied by
many authors, the ETAS (epidemic-type aftershock sequence) model which
assumes that each earthquake can trigger other earthquakes
(“aftershocks”). An aftershock sequence results in this model from the
cascade of aftershocks of each past earthquake. We develop the full
theory in terms of generating functions for describing the space-time
organization of earthquake sequences and develop several approximations
to solve the equations.
The calibration of the theory to the empirical observations
shows that it is essential to augment the ETAS model by taking account
of the pre-existing frozen heterogeneity of spontaneous earthquake
sources. This seems natural in view of the complex multi-scale nature of
fault networks, on which earthquakes nucleate.
Our extended theory is able to account for the empirical
observation but some discrepancies, especially for the shorter time windows,
point to limits of both our theoretical approach and of the ETAS model. 相似文献
8.
G. Pawłowski 《The European Physical Journal B - Condensed Matter and Complex Systems》2006,53(4):471-479
The extended Hubbard model in the atomic limit (AL-EHM) on a square lattice with periodic boundary conditions is studied with
use of the Monte Carlo (MC) method. Within the grand canonical ensemble the phase and order-order boundaries for charge orderings
are obtained. The phase diagrams include three types of charge ordered phases and the nonordered phase. The system exhibits
very rich structure and shows unusual multicritical behavior.
In the limiting case of tij=0, the EHM is equivalent to the pseudospin model with single-ion anisotropy
, exchange interaction W in an effective magnetic field
. This classical spin model is analyzed using the MC method for the canonical ensemble. The phase diagram is compared with
the known results for the Blume-Capel model. 相似文献
9.
S. Wermbter 《Annalen der Physik》1998,510(1):24-47
A frequency- and momentum-renormalization-group acceleration together with an analytical approach is used to obtain the retarded Green's function in the self-consistent and conserving fluctuation-exchange (FLEX) approximation for the two-dimensional Hubbard model in the normal state and in the superconducting state. The analytical expressions for this approach are given. For band-fillings near half filling the self-energy in the normal state exhibits Fermi-liquid behaviour for, low temperatures and frequencies near the chemical potential, if the momentum is chosen near the Fermi-surface. However due to the presence of large many body effects the observed Fermi-liquid region near the chemical potential and near the Fermi-surface is very small. Results for the single particle density of states, the occupation number and the spectral function are presented. The superconducting state with symmetry is obtained for U = 2 to U = 6 and a (U, n)-phase diagram for the transition temperature Tc is presented. A maximum Tc/t of 0.0275 is obtained for U = 6 near half filling. 相似文献
10.
N. Vandewalle S. Galam M. Kramer 《The European Physical Journal B - Condensed Matter and Complex Systems》2000,14(3):407-410
Percolation and jamming phenomena are investigated for random sequential deposition of rectangular needles on d=2 square lattices. Associated thresholds and are determined for various needle sizes. Their ratios are found to be a constant for all sizes. In addition the ratio of jamming thresholds for respectively square blocks and needles is also found to be
a constant . These constants exhibit some universal connexion in the geometry of jamming and percolation for both anisotropic shapes
(needles versus square lattices) and isotropic shapes (square blocks on square lattices). A universal empirical law is proposed for all three
thresholds as a function of a.
Received 27 January 2000 and Received in final form 2 February 2000 相似文献