Oral presentations  Posters and participants   


Prof. Kunio Awaga              (Department of Chemistry, Graduate School of Science, Nagoya University
                                              Furo-cho, Chikusa-ku, Nagoya 464-8602, Japan)

Email: awaga@mbox.chem.nagoya-u.ac.jp
Tel: +81-52-789-2487(O)
Fax: +81-52-789-2484 (O)

trip: Shanghai, Nov 16; Ye takes care all.
      talk on Nov 18 or 17

Spin, charge and lattice correlation in phase transitions of organic radical crystals   

Magnetic and electrical properties of organic radical solids have been studied extensively. It has been revealed that they often exhibit drastic phase transitions which are associated with significant changes in various physical parameters. In this presentation, we will review these phase transition, focusing on the spin, charge and lattice correlation in them, and will explain our recent works on heterocyclic thiazyl radicals with strong intermolecular interactions in 3D network structures; (1) TTTA exhibited a room-temperature bistability between a paramagnetic high-temperature  phase and a diamagnetic low-temperature phase. The phase control of TTTA was achieved by pressure and light irradiation. (2) BDTA made a diamagnetic-paramagnetic phase transition above room temperature, but this was always accompanied by superheating and supercooling. (3) BDTA2[Co(mnt)2] exhibited a charge-transfer phase transition at 190 K which resembled the neutral-ionic phase transition in TTF-CA. The transition in BDTA2[Co(mnt)2] brought about coordination bonding between the two components.

Prof. Jianshu Cao            (MIT, USA)

e-mail: jianshu@MIT.EDU

trip: no hotel room is needed

Statistical analysis of single molecule kinetics

This talk focuses on theoretical and numerical analysis of single molecule sequences:

(1) A transfer matrix formalism is developed to calculate the probability of single molecule sequences and to analyze various indicators ranging from two-event contours to photon statistics. An analogy to linear and non-linear spectroscopy helps understand the information content of sequences and indicators.

(2) Detailed balance violations are shown to result in detectable signatures in event histograms, which include peaks in the single molecule waiting time distribution, broken time reversal symmetry, and a lack of diagonal features in two-dimensional contours.

(3) Extracting reliable kinetic information from indicators is generally not feasible because of the noise and the binning of the data. A candidate to overcome this practical difficulty is Bayesian statistics, which avoids the data inversion problems inherent in traditional methods. Applications to the photon emission data reported in a recent single protein experiment show complex relaxation dynamics on the millisecond time-scale.

Prof. Moo Young Choi        (Department of Physics, Seoul National University
                             Seoul 151-747, Korea)

e-mail: mychoi@snu.ac.kr
Tel: +82-2-880-6615
Fax: +82-2-884-3002

trip: Hangzhou Nov 15 OZ359 14:20; depart from Hangzhou Nov 20. 
      Lily hotel, a room with two beds
      talk on Nov 16 or the morning of Nov 17
      A minibus picks up Choi, Kim, Wang, Anh-Tuan, C.Y. Lin and Chen
                         and Ito, Kaski, Landau, Machta and Novotny

Talk 1 

Physics of complex systems

Talk 2

possibly from

1) Critical currents and defect motion in superconducting arrays;
2) Stability and collective oscillations in globally coupled rotors;
3) Molecular dynamics of protein PDC-109:
   potential of mean force between two domains

Prof. Markus Deserno        (MPI fuer Polymerforschung, Ackermannweg 10,
                             55128 Mainz, Germany)                      

e-mail: deserno@mpip-mainz.mpg.de
http:   www.mpip-mainz.mpg.de/~deserno
Tel:    49-6131-379-333 
Fax:    49-6131-379-340 

trip:   Shanghai, Nov 14 LH 728 11:10am; Nov 20 to Shanghai,
        depart on Nov 21 LH 729 13:50pm.         Lily hotel

A new simulational approach to coarse-grained fluid lipid membranes

Fluid lipid membranes are two-dimensional elastic structures with
vanishing in-plane shear modulus, which form spontaneously in aqueous
solution from amphiphilic lipids.  Their tendency to self-assemble
into complex structures, the theoretical challenges in their
description, and the fact that they constitute one of the most
important structural components of all living cells have fascinated
scientists from biology up to theoretical physics and mathematics ever
since.  In my talk I will illustrate several aspects of the physics of
such membranes from a soft-matter point of view.  In particular, I
will illustrate a very efficient way of simulating such systems on a
coarse-grained level, i.e., by using highly simplified representations
of lipids and replacing the embedding solvent by suitable effective
interactions.  As an illustration, I will show, how such simulations
can shed light onto the question of membrane-curvature mediated
interactions between proteins, which adhere to the membrane and
locally bend it.


Prof. C.K. Hu               (Institute of Physics,  Academia Sinica, Taipei 11529,  Taiwan)


e-mail: huck@phys.sinica.edu.tw


trip: Hangzhou, Nov 13 then to Jinhua;  Hangzhou, Nov 15; depart, Nov 19.
   Jinxi hotel


Some Recent Developments in Simulational Approach to Protein Folding


In this talk, I briefly review some recent developments in simulation approach to protein folding. The topics under discussion include: 1. developments of algorithms and computer packages for all-atom simulations of proteins [1], 2. delvelopment of algorithm to compute volume V , surface area A, and cavities of proteins by analytic equations [2], and apply such algorithm to calculate V=A ratios for native protein structures [3], 3. Go-like model approach to folding of hbSBD{a protein with 52 amino acides [4], 4. unfolding and refolding of immunoglobulin domain I27 and ubiquitin [5].


[1] F. Eisenmenger, U. H.E. Hansmann, S. Hayryan, and C.-K. Hu. Comp. Phys.     Commu., 138, 192-212 (2001) and 174, 422 (2006); S. Hayrian, C.-K. Hu, S.-Y. Hu and R.-J. Shang. J. Comp. Chem. 22, 1287-1296 (2001); R. G. Ghulghazaryan, S. Hayryan and C.-K. Hu. J. Comp. Chem., in press.
[2] S. Hayryan, C.-K. Hu, J. Skvrivanek, E. Hayrjan, I. Pokorny.
J. Comp. Chem. 26,334 (2005); J. Busa, J. Dzurina, E. Hayryan, S. Hayryan, C.-K. Hu, J. Plavka, I. Pokorny, J. Skrivanek, and M-C. Wu. Comp. Phys. Commun. 165, 59 (2005).
[3] M.-C. Wu, M. S. Li, M. Kouza, W.-J. Ma, and C.-K. Hu, A new geometrical constraint on native protein structures, submitted for publication.
[4] M. Kouza, C.-F. Chang, S. Hayryan, T.-H. Yu, M. S. Li, T.-H. Huang, and C.-K. Hu,
Biophysical J. 89, 3353 (2005); M. Kouza, M. S. Li, E. P. O'Brien, C.-K. Hu, and D. Thirumalai. J. Phys. Chem. A 110, 671 (2006).
[5] M.-S. Li, C.-K. Hu, D. K. Klimov, and D. Thirumalai,
Proc. Natl. Acad. Sci. USA 103, 93 (2006); M.-S. Li, M. Kouza and C.-K. Hu. Biophysical J., in press.

Prof. Xiao Hu   (Computational Materials Science Center, National Institute for Materials Science,
                                Sengen 1-2-1, Tsukuba 305-0047, Japan)

e-mail: HU.Xiao@nims.go.jp
tel: +81-29-859-2661
fax: +81-29-859-2601

trip:  Hangzhou, Nov. 15, Shanghai, Nov. 18 17:00.  
       Qinghu Chen picks up. Lily hotel

Dynamics simulation for current-driven vortices with defects


Dynamics of current-driven vortices in type II superconductors with defects is relevant to many applications of superconducting state. It is also a challenge to give a theoretical picture for the physics which is related to typical glassy phenomena. Even the most advanced functional renormalization theory cannot give a satisfactory answer so far. We have performed dynamical simulations for current-driven vortices with point pins. Besides a continuous depinning transition at zero temperature, we also observed creep behaviors at finite temperatures. Both Arrhenius type and non-Arrhenius type creeps have been found depending on the strength of pinning potential. The observations from computer simulations will be discussed in the light of phenomenological theory.

Prof. Nobuyasu. Ito     (Department of Applied Physics, School of Engineering,
                                                The University of Tokyo
, Tokyo 113-8656,  JAPAN)

e-mail: ito@ap.t.u-tokyo.ac.jp

trip: Shanghai, Nov 10 JL619 13:45; Nov 11 CA1775 8:40 to Xi'an;
      Hangzhou, Nov. 15 CA1776 13:40pm,
      Hangzhou, Nov 19 JL636 13:15.  Lily hotel

Nonequilibrium simulation study of interface
Macroscopic theories like thermodynamics and hydrodynamics treat phase interface as mathematical two-dimensional objects, but in reality, they have finite thickness and interesting structures. Although the scale is nanoscopic in general, they are relevant in many macroscopic phenomena, especially in nonlinear nonequilibrium behavior. In this talk, recent results on interfaces between liquid and gas, liquid and solid, and so on, using nonequilibrium computer simulation are introduced. The density structure, transport
characteristics, and dynamical evolution of interfaces are treated.

[1] F. Ogushi, S. Yukawa and N. Ito, J. Phys. Soc. Jpn. 74 (2005) p.827
[2] F. Ogushi, S. Yukawa and N. Ito, J. Phys. Soc. Jpn. 75 (2006) 073001

Prof. Wolfhard Janke  (Institute for Theoretical Physics, University Leipzig,
                                             Augustusplatz 10 - 11, 04109 Leipzig, Germany

e-mail: Wolfhard.Janke@itp.uni-leipzig.de
phone:     +49 341 9732 725
fax:       +49 341 9732 747
secr.:     +49 341 9732 420
secr. fax: +49 341 9732 548

trip: Shanghai Nov 15 11:10; Nov 20 to Shanghai; Shanghai, Nov 23 00:15  
      Lily hotel
      Pao Chen to Pudong Shanghai picks up Janke and Wenzel

Diluted Magnets - Simulations vs Series Expansions

Prof. Kimmo Kaski   (Helsinki University of Technology, Laboratory of Computational Engineering, 
      P.O.Box 9203, FI-02015 HUT, FINLAND)

email: kimmo.kaski@hut.fi
tel.  +358 - 9 - 451 4825
fax.  +358 - 9 - 451 4833

trip: (Shanghai, Nov 11 AY57 8:05,) Xi'an (Xianyang) Nov 11 MU292 13:30,
       Hangzhou, Nov. 15 CA1776 13:40pm,
       Nov 18 to a hotel in airport Pudong Shanghai,
      (Shanghai, Nov 19  AY58  10:45)
       Jinxi hotel

Structure and tie strengths in mobile communication networks

Prof. Beom-jun Kim     (Department of Physics, BK21 Physics Research Division,
                                               and Institute of Basic Science, Sungkyunkwan University,
                                               Suwon 440-746, Korea

e-mail: beomjun@skku.edu

trip: Hangzhou, Nov 15 OZ359 14:20; Nov 19 OZ360 15:50.  Lily hotel

Quantum phase transition and finite-size scaling

We study the quantum phase transition in the one-dimensional
quantum Ising model at zero temperature. As the strength $g$
of the transverse field is changed, the system undergoes
a phase transition from ordered to disordered phases, characterized
by the spontaneous magnetization in the $z$-direction.
We apply the standard technique of the finite-size scaling
in statistical mechanics to detect the nature of the
quantum phase transition in the system. We also discuss
quantum critical behaviors at finite temperatures, and
investigate the quantum Ising model on complex networks.

Prof. David P. Landau   (Center for Simulational Physics, The Univ. of Georgia, Athens, GA 30602, U.S.)

e-mail: dlandau@hal.physast.uga.edu

trip: Shanghai, Nov 8 Northwest flight 25, 20:20pm;
      Jianqing Du picks up.
      Nov 11 CA1775 8:40 to Xi'an; Shijun Lv sees off.
      Hangzhou, Nov. 15 CA1776 13:40pm,
      Shanghai, Nov 20, depart from Shanghai, Nov 21.
      Jinxi hotel

Talk 1

Monte Carlo Simulations of Domain Growth in Compressible Ising Model


Monte Carlo simulations of Bose-Einstein condensation

H.C. Lee         (Graduate Institute of Systems Biology and Bioinformatics
                                                and Department of Physics, National Central University,
                                                Zhongli, Taiwan)


e-mail: hclee@sansan.phy.ncu.edu.tw


trip: Hangzhou, Nov 5 MF 898  15:00, Hangzhou Nov 18 MF 893 16:00. Apartment


Critical Genome

Genomic sequences have a number of remarkable characteristic
statistical properties including quasi-randomness, reverse-
complement symmetry, scale-invariance, self-similarity,
universality.  Here we show how such characteristics may be
quantified in a way that set them apart from sequences that
do not share the same properties and how they give us clear
ideas on the way genomes grew and evolved. We suggest that
genomes are self-organized critical attractors in a
universal growth and evolution process.


Prof. Jon Machta       (Univ Massachusetts, Dept Phys, Amherst, MA 01003 USA)

e-mail: machta@physics.umass.edu

trip: Xi'an, Nov. 10, CA 1205,09:45 pm;
Hangzhou, Nov. 15 CA1776 13:40pm,
Hangzhou, Nov 19, CA 1703, 09:00 Am
      Jinxi hotel    

Talk 1

Complexity, Parallel Computation and Statistical Physics

The intuition that a long history is required for the emergence of
complexity in natural systems is formalized using the notion of depth. The
depth of a system is defined in terms of the number of parallel
computational steps needed to simulate it. Depth provides an objective,
irreducible measure of history applicable to systems of the kind studied in
statistical physics. It is argued that physical complexity cannot occur in
the absence of substantial depth and that depth is a useful proxy for
physical complexity. The ideas are illustrated for a variety of systems in
statistical physics.


Talk 2

Phase transitions in the random field Ising model

The random field Ising model displays a phase transition that is governed by
a zero temperature fixed point.  In this talk, I introduce the random field
Ising model (RFIM) in the broader context of phase transitions in spin
systems.  I describe  computational methods, including the Wang-Landau
algorithm, that are useful for studying the RFIM.  The numerical results
show that there is a close connection between the zero temperature and
thermal phase transitions and demonstrate in a concrete fashion, the idea of
a zero temperature fixed point.

[1]  Phys. Rev. B74, 064418 (2006)
[2]  Phys. Rev. Lett. 95, 137208 (2005)

Prof. Y.Q. Ma        (Nanjing University,  National Laboratory of Solid State  
                                       Microstructures, Nanjing 210093, China)

e-mail: myqiang@nju.edu.cn

trip: Hangzhou, Nov., by bus.   Yuquan hotel                 

Entropy-driven ordering in soft matter

In this talk, I first present a simple review of self-organizing behaviors in soft materials, and then examine in detail the entropic effects on the structural organization on the basis of the following three examples of our recent works: 1) phase behavior in thin film of confined colloid-polymer mixtures,  2) the organization in inclusion- membrane complexes, and  3) lateral organization in supported membrane on a geometrically patterned substrate. Our purpose is  to discuss how to understand the physical mechanism of structural organization, and how to design and control novel structures of soft materials under the guidance of entropy driven ordering.


Prof. Mark A. Novotny     (Department of Physics & Astronomy, Mississippi State University)

e-mail: man40@ra.msstate.edu 
1-662-325-2688, 1-662-418-2688 (cell)
Fax:    1-662-325-8898 (FAX)

trip: Xi’an, Nov 10 Japan Airline 5793  6:40 pm,
      Hangzhou, Nov. 15 CA1776 13:40pm,
      Hangzhou, Nov. 19 Japan Airline 636  1:15 pm. Jinxi hotel

Talk 1

Dynamic Phase Transition: Simulations and Experiments of Magnetic Thin Films

Talk 2

Non-equilibrium statistical physics applied to massively parallel computing

Talk 3

Algorithms for long-time dynamic Monte Carlo simulations

Prof. Yutaka Okabe       (Department of Physics, Tokyo Metropolitan University, Japan)

email:  okabe@phys.metro-u.ac.jp

trip: Shanghai, Nov 16 Air China 11:05, Shanghai, Nov 19
      Lily hotel

Kosterlitz-Thouless transition for diluted system and duality relation

The effect of dilution on the Kosterlitz-Thouless (KT) transition
is studied.  We pay attention to the duality relations.
We investigate the two-dimensional diluted Villain model,
which has the exact duality mapping, by using the Monte Carlo
simulation with the cluster algorithm.  We also discuss
an ab-inito finite-size scaling analysis for the KT transition.

Prof. Yuko Okamoto    (Department of Physics, School of Science,
                       Nagoya University, Furo-cho, Chikusa-ku,
                       Nagoya, Aichi 464-8602, JAPAN)

e-mail: okamoto@phys.nagoya-u.ac.jp
TEL & FAX: 81(Japan)-52-789-3528

trip: Shanghai, Nov. 15 NH939 11:50, possibly leave for Shanghai Nov 18,
      Shanghai, Nov. 19 NH940 14:00.   Lily hotel

Monte Carlo and molecular dynamics simulations of protein folding

The ultimate goal of the present work is to predict protein tertiary
structures solely from the amino-acid sequence information by computer simulations of all-atom models.It is widely believed impossible to achieve this with the conventional simulation methods. This is because there exist an
astronomically large number of local minima in the energy function of the protein systems, forcing any simulation to get trapped in one of the energy local minima. Novel algorithms that can alleviate the multiple-minima problem are thus in urgent demand. We have been advocating the uses of generalized-ensemble algorithms. With these algorithms we can explore wide range of the
configurational space. The advantage of generalized-ensemble algorithms such as multicanonical algorithm and replica-exchange method lies in the fact that from only one simulation run, one can obtain not only the global-minimum state in energy but also various thermodynamic quantities as functions of temperature.  I present recent results of our folding simulations in generalized ensemble by both Monte Carlo and molecular dynamics methods.

H.E. Stanley       (Boston University, USA)

e-mail: hes@bu.edu

Cancelled due to unexpected events


Prof. Lei-Han Tang      (Department of Physics, Hong Kong Baptist University
                         Kowloon Tong, Kowloon, Hong Kong)         


email: lhtang@hkbu.edu.hk
tel: (852) 3411 7031
fax: (852) 3411 5813

trip: Hangzhou, Nov 16 - 20,  Lily hotel

Fluctuation-driven orbital ordering in a two-dimensional compass model

Interaction of d-orbitals in transition metal oxides is highly
directional and can be described by a pseudo-spin Hamiltonian
which couples real and orbital space. We consider here a classical
realization of directional coupling in two dimensions, known as
the compass model. Despite extensive degeneracy of the ground state, the
model exhibits partial orbital ordering stabilized by an entropy gap.
Transition to the disordered phase is shown to be in the Ising
universality class through exact mapping and multicanonical Monte Carlo
simulations.[1] Numerical issues related to the one- to two-dimensional
crossover which affects the determination of critical properties at the
transition will be discussed.

* In collaboration with Michael Ma and Fuchun Zhang. Work supported in
part by the RGC of the HKSAR under grant 2017/03P, and by the HKBU under
grant FRG 01-02/II-65.

[1] A. Mishra et al., Phys. Rev. Lett. 93, 207201 (2004).

Dr. Jian. Wang       (Department of Physics, National University of Singapore,
                                      Singapore 117543)

e-mail: phcwj@hotmail.com

trip: Hangzhou, Nov 15, Nov 19. Yuquan hotel  

Thermal Transport in Carbon Nanotubes


In this talk, we first review some recent progress of thermal transport in nano-structured materials, such as universal thermal conductance.  We then present simulation results on thermal transport in carbon nanotubes, both for the ballistic transport and nonlinear cases.

A mode-dependent energy transmission across a nanotube junction was calculated with the scattering boundary method within lattice dynamic approach.  Nonlinear phonon scatterings in carbon nanotubes are considered both from the phenomenological point and the first-principle view.  Nonequilibrium Green’s function is developed to describe thermal transport in nanotubes.


Dr. Bao-Sheng Yuan    (Great Eastern Life Assurance Co.Ltd.
                       1 pickering Street #13-01 Great Eastern Center
                       Singapore 048659)

E-mail: yuanbaosheng@hotmail.com

trip: Hangzhou, Nov 15 CZ3803 12:50PM;
      talk not on Nov 16.    Yuquan hotel

Scaling, Clustering and Dynamics of Volatility in Financial Time Series

Scaling, clustering and dynamics of volatility are central issues in theory of financial time series (FTS) and practice of the financial market.  In this talk, we first present a new universal feature of volatility in FTS: when the conditional probability distributions of financial asset returns are rescaled by their scale factors, they collapse into a universal curve with a power-law tail. Such universality is so generic so that it holds true irrespective of the magnitudes of the previous returns, the time durations on which the returns are measured, and the financial assets involved. We next introduce a simple phenomenological model to explain and reproduce the volatility dynamics observed in real FTS. The model not only clearly illustrates a dynamical mechanism for the emergence of the volatility dynamics but also overcomes a number of important shortcomings of the most commonly used GARCH model. We finally suggest an explanation on the underlying mechanism of the volatility dynamics with a microscopic market model we developed recently: the heterogeneous and dynamic risk aversion of market agents is a key mechanism responsible for the emergence of the volatility dynamics in FTS.       

Prof. Yi-Cheng Zhang     (Freiburg University, Switzerland)

e-mail: yi-cheng.zhang@unifr.ch

trip:  Hangzhou  Nov 15 SC4952 21:05, Hangzhou Nov 19.    Lily hotel

Heat Conduction model for social-econonic computation

Recent internet applications show that large communities with millions of
member form complex networks with all kinds of information among the nodes. We illustrate the scope and methods to calculate and predict the potential nodes. Physics computational methods suitable for extremely large networks are developed and realistic applications are envisaged.

Prof. Fan Zhong           (Zhongshan University, China)

e-mail: stszf@mail.sysu.edu.cn

trip: Hangzhou, Nov 16 20:00, Hangzhou Nov 20.     Yuquan hotel

Renormalization group theory of first-order phase transitions

Phase transitions are of great importance in a diversity of fields. They are usually classified into continuous phase transitions and first-order phase transitions (FOPTs). Whereas the former has a well-developed theoretical framework of the renormalization-group (RG) theory, no general theory has yet been developed for the latter that appear far more frequently. Focusing on the dynamics of a generic FOPT in the $\phi^{4}$ model below its critical point, we show by a field-theoretic RG method that it is governed by an unexpected unstable fixed point of the corresponding $\phi^{3}$ model. Accordingly, it exhibits a distinct scaling and universality behavior with unstable exponents different from the critical ones.

Prof. Boming Yu          (Huazhong University of Science and Technology,     
                          Wuhan 430074, China)

e-mail: yu3838@public.wh.hb.cn

trip: cancelled     

The thermal conductivity of nanofluids by Monte Carlo simulations

Dr. Hisashi Okumura   (Department of Physics, School of Science, Nagoya Univ,
                       Furo-cho, Chikusa-ku, Nagoya, Aichi, 464-8602, Japan)

e-mail: hokumura@tb.phys.nagoya-u.ac.jp
Phone:  +81-52-789-5730

trip: Shanghai, Nov. 15 NH939 11:50, possibly leave for Shanghai Nov 18,
      Shanghai, Nov. 19 NH940 14:00.     Lily hotel

Generalized Isobaric-Isothermal Molecular Dynamics Simulations of Alanine Dipeptide

We have recently proposed new generalized-ensemble algorithms
for Monte Carlo [1-3] and molecular dynamics [4, 5] simulations.
We refer to them as the multibaric-multithermal algorithms.
The multibaric-multithermal simulations perform random walks
widely both in volume space and in potential energy space.
Therefore, one can calculate isobaric-isothermal-ensemble averages
in wide ranges of temperature and pressure from only one simulation run.
We applied the multibaric-multithermal molecular dynamics algorithm
to an alanine dipeptide in water. The multibaric-multithermal simulation
samples not only wide ranges of the potential energy and the volume,
but also wide ranges of dihedral angles. This fact shows
that the multibaric-multithermal algorithm allows the simulations
to escape from any local-minimum-energy state and to sample
the configurational space more widely than the conventional
isobaric-isothermal method.
[1] H. Okumura and Y. Okamoto, Chem. Phys. Lett. 383, 391-396 (2004).
[2] H. Okumura and Y. Okamoto, Phys. Rev. E 70, 026702 (14 pages) (2004).
[3] H. Okumura and Y. Okamoto, J. Phys. Soc. Jpn. 73, 3304-3311 (2004).
[4] H. Okumura and Y. Okamoto, Chem. Phys. Lett. 391, 248-253 (2004).
[5] H. Okumura and Y. Okamoto, J. Comput. Chem. 27 379-395 (2006).

Prof. Pavel V. Prudnikov  


trip: Hangzhou, Nov 11, Hangzhou Nov 20    
      Yuquan hotel, shares a room with Pavel V. Prudnikov          

Numerical investigation of critical behavior of the three-dimensional diluted Ising model

The critical behavior of the three-dimensional randomly disordered Ising ferromagnet is an outstanding problem in both condenced matter and statistical physics. The effect of the fluctuations of the quenched random disorder on the critical behavior is of main interest.

Using Monte Carlo simulations we study the site-diluted Ising model in a wide dilution range. For samples with different spin concentrations we accurately determine by method from [1] finite size scaling functions which are expressed in terms the variable x=ζL/L, where ζL is the correlation length in a finite system of size L. Data for the three-dimensional diluted Ising model, taken at different temperatures in the critical range and for different size lattices, show excellent data collapse over the entire range of scaling variable for susceptibility and correlation length. From these finite size scaling functions we determined critical temperatures and exponents with rather high accuracy with the use corrections to scaling. The obtained both scaling functions and values of exponents demonstrate the existence two classes of universal critical behavior of diluted Ising systems with different characteristics for weakly and highly disordered systems. The obtained values of the exponents are in a good agreement with experimental results [2] and for weakly disordered systems with results of the field-theoretic description [3].


Critical temperatures and exponents

Spin concentrations

p= 0.95

p= 0.8

p= 0.6

p= 0.5

















[1] Kim J.-K., Souza A.J.F., Landau D.P. , Phys.Rev. E54, 2291 (1996).

[2] Folk R., Holovatch Yu., Yavorskii,  Phys.Usp. 173, 175  (2003).

[3] Pakhnin D.V., A.I.Sokolov A.I., Phys. Rev. B61, 15130 (2000);
Pelissetto A., Vicari E.,Phys. Rev. B62,6393 (2000).

Prof. Vladimir V. Prudnikov    

e-mail:  prudnikv@univer.omsk.su

trip: Hangzhou, Nov 11, Hangzhou Nov 20    
      Yuquan hotel, shares a room with Pavel V. Prudnikov
      Possibly another colleagues comes with.

(Mrs. Prudnikov)

Short-time critical dynamics of systems with long-range correlated disorder

recent years, much effort has been devoted to investigation of the critical behavior of solids containing quenched defects. In most papers considerations have been restricted to the case of point defects with small concentrations so that the defects and corresponding random fields have been assumed to be Gaussian distributed and δ - correlated. At the same time the question about influence of correlated disorder on the critical behavior was poorly investigated .

In this work Monte Carlo simulations of the short-time dynamic behavior are reported for three-dimensional Ising and XY models with long-range correlated disorder at criticality, in the case corresponding to linear defects. We analyze the critical short-time dynamics in systems with spin concentration p=0.8 starting separately from ordered and disordered initial states. The static and dynamic critical exponents computed under these two conditions with the use of the corrections to scaling are compared. The obtained values of the exponents are in a good agreement with results of the field-theoretic description of the critical behavior of these models in the two-loop approximation [1] and with our results of Monte Carlo simulations of three-dimensional Ising model in equilibrium state [2].


Critical exponents


Results of simulation

     Ising model  |   ХУ-model

Theoretical-field results

   Ising model    |   ХУ-model


2.489(21)    |    2.364(7)

2.495           |     2.365


0.719(22)     |   0.778(26)

0.716           |     0.760


0.375(45)     |   0.370(30)

0.350           |     0.366


0.149(11)     |   0.374(14)

--             |       --


[1] Prudnikov V.V., Prudnikov P.V., Fedorenko A.A. Field-theory approach to critical behavior of systems with long-range correlated defects, Phys. Rev. В62, 8777-8786 (2000).

[2] Dorofeev S.V., Prudnikov V.V. Monte Carlo studies of 3D Ising model with long-range correlated defects, Bulletin of Omsk University, No.4., P.28-30(2004).

Dr. Bing Wang                             (Department of Physics, BK21 Physics Research Division,
                                                    and Institute of Basic Science, Sungkyunkwan University,
                                                    Suwon 440-746, Korea

e-mail: bingbignmath@gmail.com


trip: Hangzhou, Nov 15 OZ359 14:20; Nov 19 OZ360 15:50.    Yuquan hotel


Talk 1

A High Robustness and Low Cost Model for Cascading Failures

We study numerically the cascading failure problem by using artificially created scale-free networks and the real network structure of the power grid. The capacity for a vertex is assigned as a monotonically increasing function of the load (or the betweenness centrality). Through the use of a simple functional form with two free parameters, revealed is that it is indeed possible to make networks more robust while spending less cost. We suggest that our method to prevent cascade by protecting less vertices is particularly important for the design of more robust real-world networks to cascading failures.


Optimizing synchronizability of complex networks

In this paper, we investigate the factors that affect the synchronization of system of coupled oscillators on networks. With an optimization approach, we find that even the degree variation is given, the network synchronizability can still be improved. The optimal network show some statistical properties. A network with lower degree of clustering, without modular structure and disassortative correlation may be easy to synchronize. Moreover, by measuring the loop structure of the optimal network, we find that the optimal network contains few number loops of size 3 to 5. These results may provide some insights into network design.

Dahui Wang   (Department of System Science, Beijing Normal University, Beijing 100875, China)

e-mail: wangdh@bnu.edu.cn

trip: Nov 15 - 19             Yuquan hotel

Critical Phenomena Emerging far from the Self-Organized Critical State in Sandpile

In Bak, Tang and Wiesenfeld's sandpile model, criticality will be observed when the sandpile evolves into the self-organized critical state. However, we ˉnd that criticality could emerge far from the self-organized critical state. This observation urges further research to discriminate different mechanisms of the 1/f  noise.

Prof. C.Y. Lin     (Department of Physics, National Chung Cheng University,
                                       Chia-Yi 66117, Taiwan)

e-mail: lincy@phy.ccu.edu.tw

trip: Hangzhou, Nov, 15  2:00 PM ; Nov 18         
      Lily hotel, share a double room with Chien-Fu Chen)

Numerical Renormalization Group Scheme of a Sandpile

A renormalization group (RG) scheme based on the similarity of relaxation dynamics of a sandpile is studied. It includes the multiple topplings and the grain redistribution-replacing to count a huge number of relaxation events inside a RG cell, we use a simple sampling procedure to simplify RG calculations. Result for the 3X3 RG cell show that the obtained height probabilities and area exponent are in excellent agreement with the corresponding theoretical values.

 Shi-zeng Lin  *  (Computational Materials Science Center, National Institute for Materials Science,
                            Sengen 1-2-1, Tsukuba 305-0047, Japan &
                            Zhejiang University,  Zhejiang Institute of Modern Physics, Hangzhou 310027, China)

e-mail: LIN.Shizeng@nims.go.jp 

trip:  Hangzhou, Nov 15 12:15, Hangzhou, Nov 19 13:15,    Yuquan hotel

Thermodynamic and structural quantities at 2D melting


We present numerical simulation of 2D melting with dipole-dipole interactions. A distinct hexatic phase is detected from the bond orientational correlation function. All measured structural quantities are compatible with the KTHNY theory. At the second stage, we measure the distribution of energy with the Wang-Landau algorithm. A double-peak structure of the distribution of the potential energy is observed with small system sizes. As the system size increases, two peaks tend to merge. The finite-size behavior of this two-peak structure is quite different from that of 1st order phase transitions. Our results exclude the possibility of a 1st order phase transition and imply that the thermodynamic quantities are more sensitive to the system size than the structural quantities do.


Prof. F. Roshani       (Alzahra University, Vanak, Tehran, Iran, 
                        P.Code: 19938911 76;
                        Inst for Studies in Theo Physics and Mathematics,
                        Farmanieh Building, next to Kouhe Nour Building,
                        Farmanieh Av. IPM, P.O. Box 19395-5531,Tehran, Iran)

e-mail: farinazz@yahoo.com
Fax: +98 (21) 22 28 04 15

trip: Shanghai, Nov 15  15:05,       Yuquan hotel

Phase transition in autonomous reaction-diffusion systems

A general system of particles on a D-dimensional region with boundaries is considered. Particles can inject or extract at the boundary. Two general behaviors of such systems are investigated. The stationary behavior of the system, and the dominant way of the relaxation of the system toward its stationary system. Bases on the first behavior, static phase transitions (discontinuous changes in the stationary profiles of the system) are studied. Based on the second behavior, dynamical phase transitions (discontinuous changes in the relaxation-times of the system) are studied. The investigation is specialized on systems in which the evolution equation of one-point functions are closed (the autonomous systems).  

Dr. T. Shimada         (Department of Applied Physics, School of Engineering,
                                              The University of Tokyo
, Tokyo 113-8656,  JAPAN)

e-mail: shimada@ap.t.u-tokyo.ac.jp

trip: Shanghai, Nov 14 CA920 22:05, stay in Shanghai;
      Shanghai, Nov 19 CA157 17:00.         Lily hotel

Universality in real and model ecosystems
The mechanism of producing and sustaining diversity in ecosystems, and the universal characteristics in structure and temporal behavior of ecosystems, has attracted broad interest. However theoretical studies on such complex ecosystems have been faced with the difficulty of having a natural and simple model which can yield a large system. For this reason each aspects has tended to be argued separately.
We proposed a simple population-dynamics-based model to solve this frustrated situation.
In our model, interaction terms among species have nonlinear form but that is scale-invariant against the population size. This interaction let the system spontaneously grow to rich structure under successive invasion of new species. Furthermore, the model reproduces the characteristic temporal statistics evaluated from fossil data such as the q-exponential distribution of the life span of species. Investigation of the emerging food web in the model
also show that our model and field data shares similar structure. In particular, the results suggest that the universal scaling of the spanning tree, which has been discussed using the field data which consists only of less than 100 species, is valid for larger systems.

[1]  T. Shimada, S. Yukawa and N. Ito, Self-Organization in an ecosystem",
      Artificial Life and Robotics, vol.6 (2002) p.78
[2]  T. Shimada, S. Yukawa and N. Ito, "Life-span of families in fossil data forms q-exponential
      distribution", Int. J. Mod. Phys. C14 (2003) p.1267
 [3]  T. Shimada, Y. Murase, S. Yukawa, N. Ito, and K. Aihara, "A simple model of evolving
      ecosystems", to appear in Artificial Life and Robotics, vol.11

Tao Zhou *        (University of Science and Technology of China)

e-mail: zhutou@ustc.edu

trip:               Yuquan hotel

Efficient routing, mixing routing and routing with jam-broadcasting:

A survey of recent progress of traffic dynamics on complex networks


Recently, motivated by the pioneer works in revealing the small-world effect and scale-free property of various real-life networks, many scientists devote themselves to studying complex networks. In this presentation, I will give a survey about our recent progress on network traffic dynamics, including a few unpublished works. 

1) Efficient routing on scale-free networks;   

2) Efficient routing based on local information; 

3) Critical phenomena and scaling behaviors of real and artificial traffic;  

4) Routing strategy with jam-broadcasting;

5) Mixing routing strategy.




1)  T. Zhou, et al., Dyn. Contin. Discret. Impuls. Syst. Ser. B 13, 463(2006);

     G. Yan, T. Zhou, B. Hu, Z. -Q. Fu, and B. -H. Wang, Phys. Rev. E 73, 046108(2006);

      B. -H. Wang, and T. Zhou, arXiv: physics/0609031  

2)  C. -Y. Yin, B. -H. Wang, W. -X. Wang, T. Zhou, and H. -J. Yang, Phys. Lett. A351, 220 (2006);

     W. -X. Wang, B. -H. Wang, C. -Y. Yin, Y. -B. Xie, and T. Zhou, Phys. Rev. E 73, 026111 (2006)

3)  S. -M. Cai, G. Yan, T. Zhou, P. -L. Zhou, Z. -Q. Fu, and B. -H. Wang, arXiv: physics/0608303;

     T. Zhou, Int. J. Mod. Phys. B (to be published);


Prof. Wei-Xing Zhou (East China University of Science and Technology, Shanghai 200237, China)

e-mail: wxzhou@ecust.edu.cn

trip: Hangzhou Nov 15 - 20  Yuquan hotel

Detrended fluctuation analysis for fractals and multifractals in high dimension

Dr. Chenping Zhu  (Department of Applied Phys., Nanjing Univ. of Aeronautics and Astronautics)

e-mail: chenpingzhu@yahoo.com.cn

trip:  Hangzhou, Nov,    Yuquan hotel

Self-organized evolving scale-free network model with coupled local correlations and node state multifractality

A novel scale-free network (SFN) model with small-world properties is presented. By making an altered version of the seceder model as the mechanism of local correlation of node states, we describe the individual character of being different from others, and we couple the evolution of topological structure with updating of node states to reveal self-organized behavior of the system by numerical simulation. Not only structural properties, such as power-law degree distribution p(k), large clustering coefficient C, short path length L,  power-law correlations of both C(k) and assortativity r(N) can emerge out from the evolution, but also functional aspect reflected by multifractality of collective behavior of node states w(i) emerge out simultaneously. In addition, the spontaneous ranking behavior of node states gives support to the assumption of lately ranking model on SFN with an independent underlying mechanism.

Junwen Mao (F)         (Huzhou Normal University, China)

e-mail: jwmao@hutc.zj.cn,jwmao@zimp.zju.edu.cn 


Recent progress on heat conduction in one-dimensional gas channels

We give a brief review of the past development of model studies on
one-dimensional heat conduction. Particularly, we describe recent
achievements on the study of heat conduction in one-dimensional
gas models including hard-point gas model and billiard gas
channel. For a one-dimensional gas of elastically colliding
particles of unequal masses, heat conduction is anomalous due to
momentum conserving and the divergence exponent of heat
conductivity is estimated as $\alpha\approx0.33$ in $\kappa \sim
L^\alpha$. Moreover, with billiard models, it is found that
exponent instability is not necessary for normal heat conduction.
The connection between heat conductivity and diffusion is
investigated. A recently proposed model with a quantized degree of freedom to
study the heat transport in quasi-one dimensional system is illustrated, in
which three distinct temperature regimes of heat conductivity is
manifested. The establishment of local thermal equilibrium~(LTE)
in homogeneous and heterogeneous systems is also discussed. Some
new progress is reported. Finally, we give a summary with an
outlook for further study about the problem of heat conduction.

B. Zheng   (Zhejiang University,  Zhejiang Institute of Modern Physics, Hangzhou 310027, China)

e-mail: bozheng@zju.edu.cn,
tel: 86-571-87952753 Fax: 86-571-87952754


           Posters in the webpage

Prof. Bing-Hong Wang    (Department of Modern Physics,
                         University of Science and Technology of China
                         Hefei, Anhui 230026, P.R.China)

Email: bhwang@ustc.edu.cn
Phone: (86-551) 3601206(H), 3607407(O)

trip: Hangzhou, Nov 15 HU-7961 12:00; Hangzhou, Nov 16 8C-8258 18:45.
      Lily hotel

Ms. Ming Zhao (F) *                (University of Science and Technology of China)

e-mail: zhaom17@mail.ustc.edu.cn

trip:   Yuquan hotel

Better synchronizability predicted by a new coupling method

Ming Zhao^1, Tao Zhou^1, Bing-Hong Wang^1, Qing Ou^2, and Jie Ren^1

1. Department of Modern Physics, University of Science and Technology of China, Hefei 230026, PR China
2. Department of Automation, University of Science and Technology of China, Hefei 230026, PR China

In this paper, inspired by the idea that different nodes should play different roles in network synchronization, we bring forward a coupling method where the coupling strength of each node depends on its neighbors' degrees. Compared with the uniform coupled method and the recently proposed Motter-Zhou-Kurths method, the synchronizability of scale-free networks can be remarkably enhanced by using the present coupled method, and the highest network synchronizability is achieved at β=1 which is similar to a method introduced in [AIP Conf. Proc. 776, 201 (2005)].

Ms Wenjie Bai (F) *       (Dept of Modern Physics, Univ of Science and Technology of China)

e-mail: wjbai@mail.ustc.edu.cn

trip: Hangzhou, Yuquan hotel

Epidemic spreading on heterogeneous networks with identical infectivity

Wen-Jie Bai, Tao Zhou, and Bing-Hong Wang

Department of Modern Physics, University of Science and Technology of China

In the previous studies of epidemic spreading on scale-free networks, there exists an underlying assumption that the infectivity of each node is equal to its degree. This assumption is not valid in some real situation, such as the broadcasting process, the sexual disease spreading, the email service systems, the network marketing process, and so on. In this presentation, we propose a susceptible-infected (SI) and susceptible-infected-removed (SIR) model, in which, at each time step, each node can only contact a constant number, $A$, of neighbors.

For SI model: We found that the infected population grows in an exponential form with the time scale proportional to the spreading rate. Further more, by numerical simulation, we demonstrated that the targeted immunization of the present model is much less efficient than that of the standard susceptible-infected model.

For SIR model: We found that on scale-free networks, the density of the recovered individuals in the present model shows a threshold behavior. We obtained the analytical results using the mean-field theory and find that the threshold value equals $1/A$, indicating that the threshold value is independent of the topology of the underlying network. The simulations agree well with the analytic results. Furthermore, we studied the time behavior of the epidemic propagation and found a hierarchical dynamics with three plateaus. Once the highly connected hubs are reached, the infection pervades almost the whole network in a progressive cascade across smaller degree classes. Then, after the previously infected hubs are recovered, the disease can only propagate to the class of smallest degree till the infected individuals are all recovered.


Background papers (reviews on epidemic spreading on complex networks)
[1] R. Pastor-Satorras, and A. Vespignani, Epidemics and immunization in   
    scale-free networks. In: S. Bornholdt, and H. G. Schuster (eds.) Handbook 
    of Graph and Networks, Wiley-VCH, Berlin, 2003.
[2] S. Boccaletti, V. Latora, Y. Moreno, M. Chavez, and D. -U. Hwang, Phys.
    Rep. 424, 175 (2006).
[3] T. Zhou, Z. -Q. Fu, and B. -H. Wang, Prog. Natl. Sci. 16, 452 (2006).

Technical papers (papers relative to this presentation)
[1] M. Barthelemy, A. Barrat, R. Pastor-Satorras, and A. Vespignani,
    Phys. Rev. Lett. 92, 178701 (2004).
[2] Y. Moreno, R. Pastor-Satorras, and A. Vespignani,
    Eur. Phys. J. B 26, 521 (2002).
[3] T. Zhou, J. -G. Liu, W. -J. Bai, G. Chen, and B. -H. Wang,
    arXiv: physics/0604083 (Phys. Rev. E In Press).
[4] W. -J. Bai, T. Zhou, and B. -H. Wang, Immunization of Susceptible-Infected
    model on scale-free networks (Int. J. Mod. Phys. C to be published).
[5] R. Yang, B. -H. Wang, W. -J. Bai, W. -X. Wang, and T. Zhou,
    arXiv: physics/0609150 (Phys. Lett. A to be published).

Mr. Jie Ren *                          (Dept of Modern Physics, Univ of Science and Technology of China)

e-mail:   renjie@mail.ustc.edu.cn

trip: Yuquan hotel

Co-evolution of Prisoner’s Dilemma Game and Networks

Jie Ren1, Wenxu Wang1, 2, Guanrong Chen2, Binghong Wang1

1. The Center of Nonlinear Science, University of Science and Technology, Hefei 230026, China

2. Department of Electronic Engineering, City University of Hong Kong, HK SAR, China

Game theory provides a useful framework for describing the evolution of systems consisting of selfish individuals. The prisoner’s dilemma game (PDG) as a metaphor for investigating the evolution of cooperation has drawn considerable attention. In the PDG, unstable cooperation is contrary to the real observations and this disagreement motivates numerous extensions of the original model to better reproduce the emergence and persistence of cooperation. Enlightened by the work of Nowak and May, who figured out that the PDG with a simple spatial structure can induce emergence of cooperation, recent attention has been focused on the effect of the underlying network structure on the cooperative behavior in the game. With recent discoveries of small-world and scale-free structural features in the real-world networks, evolutionary games are naturally considered on networks with these kinds of properties. Interestingly, Santos and Pacheco found that “scale free networks provide a unifying framework for the emergence of cooperation”.

Most studies of evolutionary games over networks are based on static network structures. However, it has been pointed out that the network structure may coevolve with the game, where each individual would choose its co-players to gain more benefits, which induces the evolution of their relationship network. From this perspective, in the present paper we propose an evolutionary network model with respect to the coevolution of the game and the network for characterizing the dynamics of some social and economic systems. In the model, each node represents an agent who plays the PDG with all its immediate neighbors simultaneously. Since growth is a common feature among networked systems, we assume that the network continuously grows by adding new agents to the existent network. We focus on the evolution of the network structure together with the cooperative behavior reflected by the density of cooperators and show how the dynamics of the game affect the growth pattern of the network and how the evolution of the network influence the cooperative behavior in the game.

Simulation results show that the payoff preferential attachment mechanism leads to the emergence of a small-world and scale-free structural property. Moreover, we found that the network has positive assortative behaviors, which are consistent with the observations of some real social networks. In parallel, we found that the evolution of the underlying network structure remarkably promotes the cooperation level of the game. Moreover, we found that the wealth of the agent show a power-law distribution which is common in realistic world, called Pareto law.

Our work might provide a new insight into the emergence of social networks and Pareto law of wealth distribution.

Mr. Sandro Wenzel *            (Institute for Theoretical Physics, University Leipzig,
                                              Augustusplatz 10 - 11, 04109 Leipzig, Germany

e-mail: Wolfhard.Janke@itp.uni-leipzig.de

trip: Shanghai Nov 15, 11:10; Shanghai, Nov 23, 00:15   Lily or Yuquan hotel

Mr. Kiet Hoang Anh-Tuan *  (Department of Physics, BK21 Physics Research Division,
                                                     and Institute of Basic Science, Sungkyunkwan University,
                                                     Suwon 440-746, Korea

e-mail: hatkiet@skku.edu

trip: Hangzhou, Nov 15 OZ359 14:20; Nov 19 OZ360 15:50.  Yuquan hotel

Realistic correlation between arrival and execution rates in human dynamics

We study the power-law distribution of the waiting times observed
in individual human activities, with focus on the role of the
correlation between the arrival rate $\lambda$ and the execution
rate $\mu$. Based on everyday experiences that we tend to
increase the execution rate of tasks upon the increase of the arrival rate,
we extend the previous model so that $\mu(t)$ at time $t$
is assumed to be positively correlated with $\lambda(t)$.
We observe that the waiting time ($\tau$) distributions unanimously follow
the power-law form as $P(\tau) \sim \tau^{-1.5}$
in accord with previous findings.
We also use the empirical data of email communications to seek
a more realistic relation between $\lambda(t)$ and $\mu(t)$.

Ms  Li Wang * (F)            (Department of Applied Physics, Nanjing University of Aeronautics and
                                                  Astronautics, China)

e-mail: vivianwl@163.com

trip: Yuquan hotel

Mr. Liang Tian              (Department of Applied Physics, Nanjing University of Aeronautics and
                                                  Astronautics, China)

e-mail: winstonye@163.com

trip: Yuquan hotel

Universal Scaling Behavior of Clustering Coefficient Induced by Deactivation Mechanism

We propose a model of network growth that generalizes the deactivation model previously suggested for complex networks. Several topological features of this generalized model, such as the
degree distribution and clustering coefficient, have been investigated analytically and by simulations. A scaling behavior of clustering coefficient $C \sim 1/M$ is theoretically obtained, where
$M$ refers to the number of active nodes in the network. We discuss the relationship between the recently observed numerical behavior of clustering coefficient in the coauthor and paper citation networks and our theoretical result. It shows that both of them are induced by deactivation mechanism. By introducing a perturbation, the generated network undergoes a transition from large- to small-world,
meanwhile the scaling behavior of $C$ is conserved. It indicates that $C \sim 1/M$ is a universal scaling behavior induced by deactivation mechanism.


PHYSICAL REVIEW E 74, 046103(2006)

Mr. Yang Wang,           (Mathematics Department, Tongji University, Shanhai, China)

e-mail: yangyanghouse@163.com

trip: Yuquan hotel

Prof. Dayin Hua         (Departemnt of Physics, Ningbo University, Ningbo 315211, China)
e-mail: huadayin@nbu.edu.cn
trip: Hangzhou, Nov 16-18, Yuquan hotel
one colleague 

Luo-luo Jiang (*)      (Departemnt of Physics, Ningbo University, Ningbo 315211, China)
e-mail: g04c07020102@email.nbu.edu.cn

Prof. Linrong Dong      (Wenzhou University, Wenzhou, China)

e-mail: dlingrong@sohu.com

trip: Yuquan hotel

Prof. Wenjun Shi


e-mail: swjyeah@126.com

trip:   Yuquan hotel

Jie Sun                (Huzhou Normal University, China)

e-mail: jwmao@hutc.zj.cn,

trip: Nov 15 - 18

Mr. Chien-Fu Chen *       (Department of Physics, National Chung Cheng University,
                                                 Chia-Yi 66117, Taiwa)

e-mail: lincy@phy.ccu.edu.tw

trip: Hangzhou, Nov, 15 14:00; Nov. Shares a room with C.Y. Lin

Effects of Bulk Dissipation on the Critical Exponents of a Sandpile

Bulk dissipation of a sandpile on a square lattice with the periodic boundary condition is investigated through a dissipating probability $f$ during each toppling process We find that the power-law behavior is broken for $f > 10^{-1}$ and not evident for $10^{-1}>f>10^{-2}$In the range $10^{-2} \ge f \ge 10^{-5}$, numerical simulations for the toppling size exponents of all, dissipative, and last waves have been studied. Two kinds of definitions for exponents are considered: the exponents obtained from the direct fitting of data and the exponents defined by the simple scaling. Our result shows that the exponents from these two definitions may be different.

Dr. Haihua Pan   (Center for Biomaterials and Biopathways, Chemistry Dept,
                  Zhejiang University, Hangzhou,310027, China)        

e-mail: panhh@zju.edu.cn,pan_hh@hotmail.com
Tel: +86-571-87953736

The Adsorption behaviours of Amino Acids on Hydroxyapatite {100} and {001} faces by Molecular Dynamic simulations

Hydroxyapatite (HAP) is considered as one of important models for biological minerals. [S. Mann, Mathew 2001]. The interfacial structure of HAP and the adsorption behaviours of biomolecule on HAP faces, which is thought to be very important for the determination of the bioactivity and morphology of crystal, are still elusive in atomic or molecular detail. Sodium Glutamate and glycine amino acids on the {100} and {001} crystalline faces of HAP have been studied by using molecular dynamic simulations (MD). It has been found that different amino acids shows different adsorption pattern; but they share the same character that they adsorb on HAP crystalline faces with its positive charge groups occupy the Ca1 or Ca2 sites, and its negative ones occupy P or OH sites precisely. Though covered by amino acids, it still have some space for water to adsorb on it’s own sites in between the amino acids. The adsorbed amino acids occupy HAP specific site, thus inhibit the growth of HAP.

Taking the adsorption energy into consideration, glutamate is easier to adsorb especially on HAP {100} faces. Glycine is easier to adsorbed on {100} faces when the occupancy is relatively low (below 4/24 Å-2), but it prefers to stay on {001} faces when in high occupation condition (>16/24 Å-2). The surfactivity of glutamate on {100} faces is the strongest (Dg/Dc = -0.556 kJ/mol); then is the glutamate (Dg/Dc = -0.367 kJ/mol) and glycine (Dg/Dc = -0.357 kJ/mol) on {001} faces; the ability to decrease the surface energy for glycine on {001} is the weakest (Dg/Dc = -0.133 kJ/mol). There is synergistic adsorption effect for glycine and glutamate on HAP {001} faces, but shows self-inhibit effect for glycine and glutamate on {100} faces. The adsorbed amino acids decreased the interfacial energy of HAP for {100} and {001} faces, thus may regulate the morphology of crystal.

These findings can explain the amino acids type and concentration dependant regulation of the growth and morphology of HAP crystal. 


[1] Mathew M, Takagi S. J. Res. Natl. Inst. Stand. Technol., 2001,106(6):1035[2] S. Mann, Biomineralization; Principles and Concepts in Bioinorganic Materials Chemistry, Oxford University Press, 2001.

Prof. Peiqing Tong     (Nanjing Normal University, China)


e-mail: pqtong@pine.njnu.edu.cn

trip: Yuquan hotel

Ms Tian Qiu            (Nanchang University of Science and Tech, China)


trip: Nov 16 -


A student            (Tongji Univ)




Y.Q. Ma's three students        (Nanjing University,  National Laboratory of Solid State  
                                                        Microstructures, Nanjing 210093, China)

e-mail: myqiang@nju.edu.cn

trip: Nov 15 - 16, Yuquan hotel

Fei Ren               (Zhejiang University, China)

Jie Shen

Li-xin Zhong

Xia-ming Zhu

Jian-qing Du

Nengji Zhou

Geyu Liang

Asad Ahmed

Pao Chen

Shijing Lv

Ruihua Dong


Prof. H.P. Ying         (Zhejiang University, China)


e-mail: hpying@zimp.zju.edu.cn



Dr. Zhao-xin Xu


Ph D students

Mr. Hong-wei Fang

Prof. Qinghu Chen        (Zhejiang University, China)

e-mail: qhchen@zju.edu.cn


Ph D students

Ms Huan Liu

Ms Ting Xiao

Prof. Hong Zhang    (Zhejiang University, China)

Prof. Xin Wan       (Zhejiang University, China)

5 students                         (East China University of Science and Technology, Shanghai 200237, China)