Microcanonical Monte Carlo Simulation of 2D 4-State Potts Model

Monte Carlo simulation of two dimensional 4 state Potts model has been carried out in microcanonical ensemble. The simulations were done on a 30 × 30 system with periodic boundary conditions. The temperature dependence of energy and order parameter has been calculated. The transition in 4-state Potts model is concluded to be first-order in nature. The transition temperature and latent heat of the first-order transition have been found to be 0.92 and 0.18, respectively.

Detection of meso-micro scale surface features based on microcanonical multifractal formalism

Synthetic aperture radar （SAR） is an effective tool to analyze the features of the ocean. In this paper, the microcanon- ical multifractal formalism is used to analyze SAR images to obtain meso-micro scale surface features. We use the Sobel operator to calculate the gradient of each point in the image, then operate continuous variable scale wavelet transform on this gradient matrix. The relationship between the wavelet coefficient and scale is built by linear regression. This relation- ship decides the singular exponents of every point in the image which contain local and global features. The manifolds in the ocean can be revealed by analyzing these exponents. The most singular manifold, which is related to the streamlines in the SAR images, can be obtained with a suitable threshold of the singular exponents. Experiments verify that application of the microcanonical multifractal formalism to SAR image analysis is effective for detecting the meso-micro scale surface information.

Implementation of a microcanonical variational transition state theory for direct dynamics calculations of rate constants

An implementation of the variational quantum RRKM program is presented to utilize the direct ab initio dynamics approach for calculating k(tE, J), k(E) and k(T) within the framework of the microcanonical transition state (μTST) and microcanonical variational TST (μVT) theories. An algorithm including tunneling contributions in Beyer-Swinehart method for calculating microcanonical rate constants is also proposed. An efficient piece-wise interpolation method is developed to evaluate the Boltzmann integral in calculation of thermal rate constants. Calculations on several test reactions, namely the H(D)2CO→ H(D)2 + CO, CH2CO→CH2 + CO and CH4 + H→CH3 + H2 reactions, show that the results are in good agreement with the previous rate constants calculations. This approach would require much less computational resource.

A multi-dimensional microcanonical Monte Carlo study of S_0→T_1 intersystem crossing of isocyanic acid

A general formula for the multi-dimensional Monte Carlo microcanonical nonadiabatic rate constant expressed in configuration space is applied to calculate the rate of intersystem crossing(ISC) between the ground(S0) and first excited triplet(T1) states for isocyanic acid.One-,two-and three-dimensional potential energy surfaces are constructed by coupled-cluster single-double CCSD calculations,which are used for Monte Carlo sampling.The calculated S0→T1 ISC rate is in good agreement with experimental findings,which gives us a reason to believe that the multi-dimensional Monte Carlo microcanonical nonadiabatic rate theory is a very effective method for calculating nonadiabatic transition rate of a polyatomic molecule.

Comparison between hydrogen-transfer and fluoro-transfer reactions on the microcanonical unimolecular rate constants

The microcanonical rate constants for the hydrogen-transfer process of HCCF (reaction 7) and the fluoro-transfer process of FCCF (reaction 8) are carried out with tunneling correction and curvature correction. The results show that the tunneling effects and curvature effects on the rate constant of reaction 7 is quite different from that of reaction 8. The rate constants for different rotational states are also studied for these reactions.

Tricritical and Critical Exponents in Microcanonical Ensemble of Systems with Long-Range Interactions

We explore the tricritical points and the critical lines of both Blume Emery Griffiths and Ising model within long-range interactions in the microcanonical ensemble.For K = Kmtp,the tricritical exponents take the valuesβ = 1/4,1 =γ^-≠γ^+ = 1/2 and 0 =α^-≠α^+ =-1/2,which disagree with classical(mean ffeld) values.When K > Kmtp,the phase transition becomes second order and the critical exponents have classical values except close to the canonical tricritical parameters(Kctp),where the values of the critical expoents become β = 1/2,1 = γ^-≠γ^+= 2and 0 =α^-≠α^+ = 1.

Microscopic ensemble bootstrap in phase space

The bootstrap method which has been studied under many quantum mechanical models turns out to be feasible in microcanonical ensembles as well.While the approach of Nakayama(2022 Mod.Phys.Lett.A 372250054)produces a sector when energy is negative,in this paper we report a method that has stronger constraints and results in a smaller region.We also study other models to demonstrate the effectiveness of our method.

Classical model of interaction of 1-D helium with an inte nse ultrashort laser pulse

The dynamical process of interaction of one-dimensional helium with an intense ultrashort laser pulse has hen studied with a classical theory. Using the ensemble average method in the classical theory, the probability evolutions of the single and double ionization for the helium are simulated and the simulation results are analyzed.

An effective method for service components selection based on micro-canonical annealing considering dependability assurance

Distributed virtualization changes the pattern of building software systems. However, it brings some problems on dependability assurance owing to the complex social relationships and interactions between service components. The best way to solve the problems in a distributed virtualized environment is dependable service components selection. Dependable service components selection can be modeled as finding a dependable service path, which is a multiconstrained optimal path problem. In this paper, a service components selection method that searches for the dependable service path in a distributed virtualized environment is proposed from the perspective of dependability assurance. The concept of Quality of Dependability is introduced to describe and constrain software system dependability during dynamic composition. Then, we model the dependable service components selection as a multiconstrained optimal path problem, and apply the Adaptive Bonus-Penalty Microcanonical Annealing algorithm to find the optimal dependable service path. The experimental results show that the proposed algorithm has high search success rate and quick converges.

Isospin dependence of nuclear multifragmentation in statistical model

The evolution of nuclear disintegration mechanisms with increasing excitation energy, from compound nucleus to multifragmentation, has been studied by using the Statistical Multifragmentation Model （SMM） within a micro-canonical ensemble. We discuss the observable characteristics as functions of excitation energy in multifragmentation, concentrating on the isospin dependence of the model in its decaying mechanism and break-up fragment configuration by comparing the A0 = 200, Z0 = 78 and A0 = 200, Z0 = 100 systems. The calculations indicate that the neutron-rich system （Z0 = 78） translates to a fission-like process from evaporation later than the symmetric nucleus at a lower excitation energy, but gets a larger average multiplicity as the excitation energy increases above 1.0 MeV/u.