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Novel size effect in mesoscopic chemical oscillation systems. Zhonghuai Hou ( 侯中怀 ) Sep. 2008, Hefei Department of Chemical Physics Hefei National Lab for Physical Sciences at Microscale University of Science & Technology of China. Our Research Interests.
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Novel size effect in mesoscopic chemical oscillation systems Zhonghuai Hou (侯中怀) Sep. 2008, Hefei Department of Chemical Physics Hefei National Lab for Physical Sciences at Microscale University of Science & Technology of China
Our Research Interests • Nonlinear Dynamics in Mesoscopic Chemical Systems • Dynamics of Complex Networks • Nonequilibrium Thermodynamics of Small Systems (Fluctuation Theorem) • Multiscale Modeling of Complex Systems Nonequilibrium +Nonlinear+ Complexity
Outline • Introduction the question • Optimal Size Effect • Stochastic Normal Form Theory • Conclusion
Nonlinear Chemical Dynamics Stationary spatial structures in reaction-diffusion systems Two or more stable states under same external constraints Travelling/Target/Spiral/Soliton … waves Temporally Periodic Variations of Concentrations Aperiodic/Initial condition sensitivity/strange attractor… Strange Attractor The Lorenz System Chemical turbulence CO+O2 on Pt Surface Science 2001 Turing Pattern BZ Reaction System PNAS 2003 Synthetic transcriptional oscillator (Repressilator) Nature 2002 Calcium Spiral Wave in Cardiac Tissues Nature 1998 Reactive/Inactive bistabe CO+O2 on Pt filed tip PRL1999 Genetic Toggle Switch In E. Coli Nature 2000 Cellular Pattern CO Oxidation on Pt PRL 2001 Rate Oscillation CO+O2 Nano-particle Catal.Today 2003 PEEM Image CO Oxidation on Pt PRL 1995 • far-from equilibrium, self-organized, complex, spatio-temporal structures • Oscillation • Multistability • Patterns • Waves • Chaos Collective behavior involving many molecular units Nonequilibrium Statistical Mechanics
Mesoscopic Reaction System Molecular Fluctuation N, V (Small) ? Chemical Oscillation Regularity Stochasticity Nonlinear Chemical Dynamics • Heterogeneous catalysis - field emitter tips - nanostructured composite surface - small metal particles • Sub-cellular reactions - gene expression - ion-channel gating - calcium signaling ……
We already know ... • Noise Induced Pattern Transition • Disorder sustained spiral waves • Taming Chaos by Topological Disorder • Ordering Bursting Chaos in Neuron Networks • Y. Gong,Z.Hou, H.Xin. ChemPhysChem 6,1042(2005);M. M.Wang, Z.Hou, H.Xin. ChemPhysChem7,579( 2006); Z.Hou, et al., PRL 81, 2854 (1998) Z.Hou, et al., PRL 89, 280601 (2002) F. Qi, Z.Hou, H. Xin, PRL 91, 064102 (2003) • Noise and disorder play constructive roles in nonlinear systems
Modeling of Chemical Oscillations • Macroscopic level: Deterministic, Cont. N Species, M reaction channels, well-stirred in V Reaction j: Rate: Hopf bifurcation leads to oscillation
Modeling of Chemical Oscillations Exactly Kinetic Monte Carlo Simulation (KMC) Gillespie’s algorithm Approximately Internal Noise Deterministic equation • Mesoscopic Level: Stochastic, Discrete Master Equation
New: Noise Induced Oscillation • A model system: The Brusselator Stochastic Deterministic FFT Noisy Oscillation
Optimal System Size Best performance Optimal System size for mesoscopic chemical oscillation Z. Hou, H. Xin. ChemPhysChem 5, 407(2004)
Seems to be common … • Internal Noise Stochastic Resonance in a Circadian Clock SystemJ.Chem.Phys.119, 11508(2003) ? Common mechanism • System size bi-resonance for intracellularcalcium signaling ChemPhysChem 5, 1041(2004) • Double-System-Size resonance for spiking activity of coupledHHneurons ChemPhysChem 5, 1602(2004) • Optimal Particle Size for Rate Oscillation in COOxidationonNanometer-SizedPalladium(Pd) Particles J.Phys.Chem.B 108, 17796(2004) • Effects of Internal Noise for rate oscillations during CO oxidation on platinum(Pt) surfaces J.Chem.Phys.122, 134708(2005) Analytical Study • Internal Noise Stochastic Resonance of syntheticgenenetwork Chem.Phys.Lett. 401,307(2005)
Analytical study • Main idea Fact: all happens close to the HB Question: common features near HB? Answer: normal form on center manifold
Analytical study • Stochastic Normal Form
Analytical study • Stochastic Averaging
Analytical study(…) • Probability distribution of r Fokker-Planck equation Stationary distribution Most probable radius Noise induced oscillation
Analytical study(…) • Auto-correlation function
Analytical study(…) • Power spectrum and SNR Optimal system size:
Analytical study(…) Universal near HB System Dependent ChemPhysChem 7, 1520(July 2006) ; J. Phys.Chem.A 111, 11500(Nov. 2007); New J. Phys. 9, 403(Nov. 2007) ;
System Size Bi-resonance System Size Biresonance for Intracellular Calcium Signaling J. Zhang, Z.H.Hou, H.W.Xin, ChemPhysChem 5, 1041(2004)
System Size Bi-resonance Effects of Internal Noise for Rate Oscillation During CO Oxidation Z.Hou, T. Rao, H.Xin. J.Chem.Phys. 122,134708(2005)
N个HH神经元的耦合体系 …… S S S S N Double System Size Resonance Log(S) Coupled Neuron Network: ChemPhysChem 5,1062(2004) Coupled Calcium Oscillation: Phye.Rev.E 74 031901(2006)
Summary • In mesoscopic chemical systems, molecular fluctuations can induce oscillation even outside the deterministic oscillatory region • Optimal system size exists, where the noise-induced oscillation shows the best performance, characterized by a maximal SNR, a trade off between strength and regularity • Based on stochastic normal form, analytical studies show rather good agreements with the simulation results, uncovering the mechanism of NIO and OSS • System Bi-Resonance and Double System Size Resonance are observed
Acknowledgements Supported by: National science foundation (NSF) Prof. Yubing Gong (龚玉兵 鲁东大学) Prof. Jiqian Zhang (张季谦 安徽师范大学) Maosheng Wang (汪茂胜 安徽师范大学) Zhiwei Wang (王志伟 天津科技大学) Tiejun Xiao (肖铁军) Juan Ma(马娟) Ting Rao(饶汀)