共查询到20条相似文献,搜索用时 46 毫秒
1.
M. Modarres H.R. Moshfegh A. Sepahvand 《The European Physical Journal B - Condensed Matter and Complex Systems》2003,31(2):159-166
The free energy of the homogeneous electron fluid at finite temperature is obtained using the lowest order constrained variational
(LOCV) method. In order to test the convergence of cluster expansion series the three-body cluster terms are calculated with
the LOCV correlation functions. The results agree reasonably with those of Monte Carlo, coupled-cluster, perturbational expansion
etc, techniques at zero temperature. The flashing and critical temperatures as well as the critical exponent are found to
be about 0.6, 1.3 eV and 0.384 respectively. A similar liquid-gas phase transition to that of nuclear matter and liquid He3 is observed.
Received 15 April 2002 / Received in final form 19 October 2002 Published online 4 February 2003
RID="a"
ID="a"e-mail: modarres@khayam.ut.ac.ir 相似文献
2.
J.V. Jovanović S.B. Vrhovac Z.Lj. Petrović 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2002,21(3):335-342
Transport properties of ion swarms in presence of Resonant Charge Transfer (RCT) collisions are studied using Momentum Transfer
Theory (MTT). It was shown that, not surprisingly, RCT collisions may be represented as a special case of elastic scattering.
Using the developed MTT we tested a previously available anisotropic set of cross-sections for Ar+Ar
+ collisions by making the comparisons with the available data for the transverse diffusion coefficient. We also developed
an anisotropic set of Ne+Ne
+ integral cross-sections based on the available data for mobility, longitudinal and transverse diffusion. Anisotropic sets
of cross-sections are needed for Monte Carlo simulations of ion transport and plasma models.
Received 16 June 2002 / Received in final form 2nd August 2002 Published online 24 September 2002
RID="a"
ID="a"e-mail: vrhovac@phy.bg.ac.yu
RID="b"
ID="b"e-mail: zoran@phy.bg.ac.yu 相似文献
3.
V.P. Zhdanov 《The European Physical Journal B - Condensed Matter and Complex Systems》2002,29(3):485-489
To illustrate complex spatio-temporal effects which are possible in cellular reactions with a small number of particles, we
present Monte Carlo simulations of the formation of oscillatory spark-like patterns in a model completely stochastic Ca+2 oscillator. Our analysis shows that in order to observe such patterns the minimum average number of Ca+2 ions in the cytosol may be as low as about 50.
Received 21 April 2002 / Received in final form 19 June 2002 Published online 14 October 2002
RID="a"
ID="a"e-mail: zhdanov@catalysis.nsk.su 相似文献
4.
R.-D. Herzberg N. Amzal J.E. Bastin F. Becker P.M.T. Brew P.A. Butler A.J.C. Chewter J.F.C. Cocks O. Dorvaux K. Eskola J. Gerl P.T. Greenlees N.J. Hammond K. Hauschild K. Helariutta F. Heßberger M. Houry A. Hürstel R.D. Humphreys G.D. Jones P.M. Jones R. Julin S. Juutinen H. Kankaanpää H. Kettunen T.L. Khoo W. Korten P. Kuusiniemi Y. Le Coz M. Leino A.P. Leppänen C.J. Lister R. Lucas M. Muikku P. Nieminen R.D. Page T. Page P. Rahkila P. Reiter Ch. Schlegel C. Scholey G. Sletten O. Stezowski Ch. Theisen W.H. Trzaska J. Uusitalo H.J. Wollersheim 《The European Physical Journal A - Hadrons and Nuclei》2002,15(1-2):205-208
In-beam conversion electron spectroscopy experiments have been performed on the transfermium nuclei 253, 254No using the conversion electron spectrometer SACRED in nearly collinear geometry in conjunction with the gas-filled separator
RITU at the University of Jyv?skyl?. The experimental setup is discussed and the spectra are compared to Monte Carlo simulations.
The implications for the ground-state configuration of 253No are discussed.
Received: 21 March 2002 / Accepted: 16 May 2002 / Published online: 31 October 2002
RID="a"
ID="a"e-mail: rdh@ns.ph.liv.ac.uk
RID="b"
ID="b"Present address: GANIL, F-14021 Caen, France.
RID="c"
ID="c"Permanent address: IReS Strasbourg, IN2P3-CNRS, F-67037-Strasbourg, France.
RID="d"
ID="d"Present address: CEA/DIF DCRE/SDE/LDN F-91680 Bruyeres-le-Chatel.
RID="e"
ID="e"Present address: Daresbury Laboratory, Daresbury WA4 4AD, UK.
RID="f"
ID="f"Permanent address: IPN Lyon, IN2P3-CNRS, F-69037 Lyon, France. 相似文献
5.
V.V. Savkin A.N. Rubtsov T. Janssen 《The European Physical Journal B - Condensed Matter and Complex Systems》2003,31(4):525-531
The classical two-dimensional discrete frustrated φ
4
model is studied by Monte Carlo simulations. The correlation function is obtained for two values of a parameter d that determines the frustration in the model. The ground state is a ferro-phase for d
= - 0.35 and a commensurate phase with period N
= 6 for d
= - 0.45. Mean field predicts that at higher temperature the system enters a para-phase via an incommensurate state, in both cases. Monte Carlo data for d
= - 0.45 show two phase transitions with a floating-incommensurate phase between them. The phase transition at higher temperature
is of the Kosterlitz-Thouless type. Analysis of the data for d
= - 0.35 shows only a single phase transition between the floating-fluid phase and the ferro-phase within the numerical error.
Received 16 December 2002 / Received in final form 17 January 2003 Published online 6 March 2003
RID="a"
ID="a"e-mail: vladimir@shg.ru 相似文献
6.
Monte Carlo simulations are used to study the non-uniform equilibrium charge distribution along a single annealed polyelectrolyte
chain under θ solvent conditions and with added salt. Within a range of the order of the Debye length charge accumulates at
chain ends while a slight charge depletion appears in the central part of the chain. The simulation results are compared with
theoretical predictions recently given by Castelnovo et al. In the parameter range where the theory can be applied we find almost perfect quantitative agreement.
Received 7 March 2002 and Received in final form 28 May 2002 相似文献
7.
J. Ferkinghoff-Borg 《The European Physical Journal B - Condensed Matter and Complex Systems》2002,29(3):481-484
We present a new, maximum-likelihood based method to combine data from a multiple number of Monte Carlo simulations performed
within any type of ensemble. The method offers an efficient iterative scheme to obtain the density of states of a wide range
of energies as well as of other macroscopic variables. It should in particular be useful for the study of systems with a rough
energy landscape.
Received 4 June 2002 Published online 14 October 2002
RID="a"
ID="a"e-mail: borg@alf.nbi.dk 相似文献
8.
V.S. Gerdjikov G.G. Grahovski N.A. Kostov 《The European Physical Journal B - Condensed Matter and Complex Systems》2002,29(2):243-248
The class of nonlinear evolution equations (NLEE) - gauge equivalent to the N-wave equations related to the simple Lie algebra are derived and analyzed. They are written in terms of (x, t) ∈ satisfying r = rank nonlinear constraints. The corresponding Lax pairs and the time evolution of the scattering data are found. The Zakharov-Shabat
dressing method is appropriately modified to construct their soliton solutions.
Received 20 October 2001 / Received in final form 30 April 2002 Published online 2 October 2002
RID="a"
ID="a"e-mail: gerjikov@inrne.bas.bg 相似文献
9.
Bo-Wen Xiao Xin Qian Bo-Qiang Ma 《The European Physical Journal A - Hadrons and Nuclei》2002,15(4):523-527
The electromagnetic form factor of the kaon meson is calculated in the light-cone formalism of the relativistic constituent
quark model. The calculated K+ form factor is consistent with almost all of the available experimental data at low-energy scale, while other properties
of the kaon could also be interrelated in this representation with reasonable parameters. Predictions of the form factors
for the charged and neutral kaons at a higher-energy scale are also given, and we find the non-zero K0 form factor at Q
2≠ 0 due to the mass difference between the strange and down quarks inside K0.
Received: 21 June 2002 / Accepted: 29 July 2002 / Published online: 3 December 2002
RID="a"
ID="a"e-mail: mabq@phy.pku.edu.cn
Communicated by A. Sch?fer 相似文献
10.
J.C. Cao X.L. Lei 《The European Physical Journal B - Condensed Matter and Complex Systems》2002,29(4):553-559
We have extended the balance equations to account for conduction-valence interband impact ionization (II) process induced
by an intense terahertz (THz) electromagnetic irradiation in semiconductors, and applied them to study the II effect on electron
transport and electron-hole pair generation-recombination rate in THz-driven InAs/AlSb heterojunctions (HJ). As many as needed
multiphoton channels are self-consistently taken into account for yielding a given accuracy. The time evolution of transport
state including THz-radiation-induced II process are monitored in details by an extensive time-dependent analysis. Two different
physical stages, the quasi-steady state and the complete steady-state, are clearly identified from the present calculations.
Intersubband electron transfer rate and net electron-hole generation rate are derived as functions of the THz radiation strength
E
ac for various radiation frequencies from f
ac = 0.42 to 6 THz at lattice temperatures T = 6 K. It's indicated that the THz radiation with a larger E
ac or a lower f
ac, has a stronger effect on electron transport and II process. Qualitative agreement is obtained between the calculated electron-hole
generation rate and the available experimental data for InAs/AlSb HJ's at T = 6 K.
Received 24 May 2002 / Received in final form 26 August 2002 Published online 31 October 2002
RID="a"
ID="a"e-mail: jccao8@hotmail.com 相似文献
11.
Steven C. Pieper 《The European Physical Journal A - Hadrons and Nuclei》2002,13(1-2):75-79
Quantum Monte Carlo calculations using realistic two- and three-nucleon interactions are presented for nuclei with up to ten
nucleons. Our Green's function Monte Carlo calculations are accurate to ∼1-2% for the binding energy. We have constructed
Hamiltonians using the Argonne v18
NN interaction and reasonable three-nucleon interactions that reproduce the energies of these nuclear states with only ∼500
keV rms error. Other predictions, such as form factors, decay rates, and spectroscopic factors also agree well with data.
Some of these results are presented to show that ab initio calculations of light nuclei are now well in hand.
Received: 1 May 2001 / Accepted: 4 December 2001 相似文献
12.
Recent experiments have demonstrated that the dynamics in liquids close to the glass transition temperature is strongly heterogeneous.
The characteristic size of these heterogeneities has been measured to be a few nanometers at T
g. We extend here a recent model for describing the heterogeneous nature of the dynamics which allows both to derive this length
scale and the right orders of magnitude of the heterogeneities of the dynamics close to the glass transition. Our model allows
then to interpret quantitatively small probes diffusion experiments.
Received 29 March 2002 and Received in final form 11 November 2002
RID="a"
ID="a"e-mail: long@lps.u-psud.fr 相似文献
13.
S.E. Guidoni H.O. Mártin C.M. Aldao 《The European physical journal. E, Soft matter》2002,7(3):291-295
We present a one-dimensional Monte Carlo simulation for the diffusion motion of a chain of N beads. We found that the scaling exponent for the viscosity can be smaller or greater than 3. This anomalous behavior cannot be attributed to the diffusivity scaling or the length fluctuations but is due to the chain dynamics details
during diffusion in which the end beads play the key role. The viscosity exponent 3 and its expected relation with the diffusivity
exponent are recovered in the asymptotic regime (N ↦∞).
Received 24 September 2001 and Received in final form 28 January 2002 相似文献
14.
E. Caurier F. Nowacki A. Poves 《The European Physical Journal A - Hadrons and Nuclei》2002,15(1-2):145-150
Recent shell model calculations for the neutron-rich nuclei around the magic numbers N = 20, N = 28 and N = 40 are reviewed. We stress two points: i) The crucial role played by the monopole part of the effective interaction that
determines the evolution of the spherical mean field. In particular, the reduction in the quasiparticle gaps at the magic
numbers can erode or even erase the shell closures. ii) The rich variety of structures that can be found in these situations,
with coexisting deformed and spherical states, rapid changes of behaviour with N or Z, and the massive occurrence of intruder states as ground states.
Received: 21 March 2002 / Accepted: 16 May 2002 / Published online: 31 October 2002
RID="a"
ID="a"e-mail: alfredo.poves@uam.es 相似文献
15.
F. Azaiez M. Belleguic D. Sohler M. Stanoiu Zs. Dombrádi O. Sorlin J. Timár F. Amorini D. Baiborodin A. Bauchet F. Becker C. Borcea C. Bourgeois Z. Dlouhy C. Donzaud J. Duprat D. Guillemaud-Mueller F. Ibrahim M.J. Lopez R. Lucas S.M. Lukyanov V. Maslov J. Mrazek C. Moore F. Nowacki B.M. Nyakó Yu.-E. Penionzhkevich M.G. Saint-Laurent F. Sarazin J.A. Scarpaci G. Sletten C. Stodel M. Taylor C. Theisen G. Voltolini 《The European Physical Journal A - Hadrons and Nuclei》2002,15(1-2):93-97
The structure of neutron-rich light nuclei around N = 20 and 28 has been investigated at GANIL by means of in-beam gamma-spectroscopy using fragmentation reactions of 36S and 48Ca beams on a Be target. Gamma-decay of relatively high-lying excited states have been measured for the first time in nuclei
around 32Mg and 44S. Level schemes are proposed and discussed for a large number of these neutron-rich nuclei around N = 20 and N = 28.
Received: 21 March 2002 / Accepted: 16 May 2002 / Published online: 31 October 2002
RID="a"
ID="a"e-mail: azaiez@ipno.in2p3.fr 相似文献
16.
R. Eryiğit C. Parlak R. Eryiğit 《The European Physical Journal B - Condensed Matter and Complex Systems》2003,33(3):251-254
We have performed a first-principles study of structural, dynamical, and dielectric properties of the chalcopyrite semiconductor
CuInS2. The calculations have been carried out within the local density functional approximation using norm-conserving pseudopotentials
and a plane-wave basis. Born effective charge tensors, dielectric permitivity tensors, the phonon frequencies at the Brillouin
zone center and mode oscillator strengths are calculated using density functional perturbation theory. The calculated properties
agree with infrared and Raman measurements.
Received 12 December 2002 / Received in final form 17 March 2003 Published online 20 June 2003
RID="a"
ID="a"e-mail: resul@ibu.edu.tr 相似文献
17.
A.G. Moreira R.R. Netz 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2002,21(1):83-96
Using a field-theoretic approach, we derive the first few coefficients of the exact low-density (“virial”) expansion of a
binary mixture of positively and negatively charged hard spheres (two-component hard-core plasma, TCPHC). Our calculations
are nonperturbative with respect to the diameters d+ and d- and charge valences q+ and q- of positive and negative ions. Consequently, our closed-form expressions for the coefficients of the free energy and activity
can be used to treat dilute salt solutions, where typically d
+∼d
- and q
+∼q
-, as well as colloidal suspensions, where the difference in size and valence between macroions and counterions can be very
large. We show how to map the TCPHC on a one-component hard-core plasma (OCPHC) in the colloidal limit of large size and valence
ratio, in which case the counterions effectively form a neutralizing background. A sizable discrepancy with the standard OCPHC
with uniform, rigid background is detected, which can be traced back to the fact that the counterions cannot penetrate the
colloids. For the case of electrolyte solutions, we show how to obtain the cationic and anionic radii as independent parameters
from experimental data for the activity coefficient.
Received 6 September 2001 / Received in final form 20 May 2002 Published online 24 September 2002 相似文献
18.
N.A. Kostov 《The European Physical Journal B - Condensed Matter and Complex Systems》2002,29(2):255-259
We consider quasi-periodic and periodic (cnoidal) wave solutions of a set of n-component dynamical systems related to Korteweg-de Vries equation. Quasi-periodic wave solutions for these systems are expressed
in terms of Novikov polynomials. Periodic solutions in terms of Hermite polynomials and generalized Hermite polynomials for
dynamical systems related to Korteweg-de Vries equation are found.
Received 15 October 2001 / Received in final form 6 March 2002 Published online 2 October 2002
RID="a"
ID="a"e-mail: nakostov@ie.bas.bg 相似文献
19.
T.S. Jensen V.E. Markushin 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2002,21(3):261-270
The deexcitation of exotic hydrogen atoms in highly excited states in collisions with hydrogen molecules has been studied
using the classical-trajectory Monte Carlo method. The Coulomb transitions with large change of principal quantum number n have been found to be the dominant collisional deexcitation mechanism at high n. The molecular structure of the hydrogen target is shown to be essential for the dominance of transitions with large Δn. The external Auger effect has been studied in the eikonal approximation. The resulting partial wave cross-sections are consistent
with unitarity and provide a more reliable input for cascade calculations than the previously used Born approximation.
Received 28 May 2002 Published online 15 October 2002
RID="a"
ID="a"e-mail: thomas@physik.unizh.ch 相似文献
20.
V.S. Gerdjikov A. Kyuldjiev G. Marmo G. Vilasi 《The European Physical Journal B - Condensed Matter and Complex Systems》2002,29(2):177-181
We consider generalizations of the standard Hamiltonian dynamics to complex dynamical variables and introduce the notions
of real Hamiltonian form in analogy with the notion of real forms for a simple Lie algebra. Thus to each real Hamiltonian
system we are able to relate several nonequivalent ones. On the example of the complex Toda chain we demonstrate how starting
from a known integrable Hamiltonian system (e.g. the Toda chain) one can complexify it and then project onto different real forms.
Received 18 October 2001 / Received in final form 24 May 2002 Published online 2 October 2002
RID="a"
ID="a"e-mail: gerjikov@inrne.bas.bg 相似文献