Stochastic Four-State Mechanochemical Model of F1-ATPase

F1-ATPase, a part of ATP synthase, can synthesize and hydrolyze ATP moleculars in which the central γ-subunit rotates inside the α3β3 cylinder. A stochastic four-state mechanochemical coupling model of F1-ATPase is studied with the aid of the master equation. In this model, the ATP hydrolysis and synthesis are dependent on ATP, ADP, and Pi concentrations. The effects of ATP concentration, ADP concentration, and the external torque on the occupation probability of binding-state, the rotation rate and the diffusion coefficient of F1-ATPase are investigated. Moreover, the results from this model are compared with experiments. The mechanochemical mechanism F1-ATPase is qualitatively explained by the model.     

Nucleon—Pair Shell Model：Magnetic Excitations for Ba Isotopes

Magnetic excitations for Ba isotopes are discussed within the nucleon-pair shell model truncated in the SD subspace.With the SD pair determined by a surface-δ interaction,M1 transitions for ^134Ba are well fitted.The M1 and M3 transitions for ^132Ba and ^130Ba are also predicted.It is shown that the statement,the collective magnetic properties are due to the orbital motion of nucleons,is approximately valid.     

The 2D Alternative Binary L—J System：Solid—Liquid Phase Diagram

The Lennard-Jones potential is introduced into the Collins model and is generalized to the two-dimensional alternative binary system.The Gibbs free energy of the binary system is calculated.According to the thermodynamic conditions of solid-liquid equilibrium,the “cigar-type ” phase diagram and the phase diagram with a minimum are obtained.The results are quite analogous to the behavior of three-dimensional substances.     

Determination of the nucleon-nucleon interaction in the ImQMD model by nuclear reactions at the Fermi energy region

The nucleon-nucleon interaction is investigated by using the improved quantum molecular dynamic （ImQMD） model with three sets of parameters IQ1, IQ2 and IQ3, in which the corresponding incompressibility coefficients of nuclear matter are different. The charge distributions of fragments are calculated for various reaction systems at different incident energies. The parameters strongly affect the charge distributions and the fragment multiplicity spectrum below the threshold energy of nuclear multifragmentation. The fragment multiplicity spectrum for 238U＋197Au at 15 A MeV and the charge distributions for 129Xe＋12~Sn at 32 and 45 A MeV, and 197Au＋197Au at 35 A MeV are reproduced by the ImQMD model with the set of parameter IQ3. It is found that： 1） The charge distribution of the fragments and the fragment multiplicity spectrum are good observables for testing the model and the parameters. 2） The Fermi energy region is a sensitive energy region for studying nucleon-nucleon interaction.     

A Quasi—One—Dimensional Model for a Solar Flux Tube

We develop the quasi-one-dimensional flux tube model with magnetohydrodynamical equations.In order to know whether the magnetic field can maintain their similar structure from photosphere to chromosphere,we suppose that the flux tube is thin in radius relative to the length,and that the quantities in the cross section are averaged.The radii of the flux tube and the magnetic field are numerically simulated.One of the important results shows that the flux tube does not expand as quickly as the existing model when it is out of the photoxphere with high velocity.This is consistent with observations of the magnetic field in the photosphere and chromosphere.     

Opacity Calculations for Non—Local Thermodynamic Equilibrium Mixtures

Based on the average atom model,a non-local thermodynamic equilibrium (non-LTE) model is developed to calculate opacity for mixtures.This model could be applied to high-Z problems.The mean ionization degrees of SiO2 of the present calculation are slightly higher compared with another model for mixtures.As an example.the opacity of Au and Nd mixture is calculated.The results show concrete non-LTE effects and the increase in opacity of the mixture is shown clearly.     

Mathematical structure of the three-dimensional（3D） Ising model

An overview of the mathematical structure of the three-dimensional(3D) Ising model is given from the points of view of topology,algebra,and geometry.By analyzing the relationships among transfer matrices of the 3D Ising model,Reidemeister moves in the knot theory,Yang-Baxter and tetrahedron equations,the following facts are illustrated for the 3D Ising model.1) The complex quaternion basis constructed for the 3D Ising model naturally represents the rotation in a(3+1)-dimensional space-time as a relativistic quantum statistical mechanics model,which is consistent with the 4-fold integrand of the partition function obtained by taking the time average.2) A unitary transformation with a matrix that is a spin representation in 2 n·l·o-space corresponds to a rotation in 2n·l·o-space,which serves to smooth all the crossings in the transfer matrices and contributes the non-trivial topological part of the partition function of the 3D Ising model.3) A tetrahedron relationship would ensure the commutativity of the transfer matrices and the integrability of the 3D Ising model,and its existence is guaranteed by the Jordan algebra and the Jordan-von Neumann-Wigner procedures.4) The unitary transformation for smoothing the crossings in the transfer matrices changes the wave functions by complex phases φx,φy,and φz.The relationship with quantum field and gauge theories and the physical significance of the weight factors are discussed in detail.The conjectured exact solution is compared with numerical results,and the singularities at/near infinite temperature are inspected.The analyticity in β=1/(kBT) of both the hard-core and the Ising models has been proved only for β0,not for β=0.Thus the high-temperature series cannot serve as a standard for judging a putative exact solution of the 3D Ising model.     

The two—atom Jaynes—Cummings model‘’s dynamic properties

The model of two two-level atoms interact with a single-mode cavity was investigated.The formulation of the time evolution operator for the two-atom Jaynes-Cummings model is Pressented by the bare-states approach.Besides,the time evolution of the two-atom common population probabilities is studied,and some novel fearures are obtained.     

A Geometry Model for Tortuosity of Flow Path in Porous Media

A simple geometry model for tortuosity of flow path in porous media is proposed based on the assumption that some particles in a porous medium are unrestrictedly overlapped and the others are not. The proposed model is expressed as a function of porosity and there is no empirical constant in this model. The model predictions are compared with those from available correlations obtained numerically and experimentally, both of which are in agreement with each other. The present model can also give the tortuosity with a good approximation near the percolation threshold. The validity of the present tortuosity model is thus verified.     

How to characterize capacitance of organic optoelectronic devices accurately

The selection of circuit model(i.e., parallel or series model) is critical when using a capacitance–frequency and capacitance–voltage technique to probe properties of organic materials and physical processes of organic optoelectronic devices. In the present work, capacitances of ITO/Alq3/Al and ITO/CuPc/Al are characterized by series and parallel model,respectively. It is found that the large series resistance comes from the ITO electrode and results in the inapplicability of the parallel model to measuring the capacitances of organic devices at high frequencies. An equivalent circuit model with consideration of the parasitical inductance of cables is constructed to derive the capacitance, and actual capacitance–frequency spectra of Alq3 and CuPc devices are obtained. Further investigation of temperature-dependent capacitance–frequency and capacitance–voltage characteristics indicates that CuPc and Al form the Schottky contact, the density and ionization energy of impurities in CuPc are obtained. Moreover, more practical guidelines for accurate capacitance measurement are introduced instead of the impedance magnitude, which will be very helpful for the organic community to investigate capacitance-related characteristics when dealing with various organic optoelectronic devices.