We use Kuramoto-like model as node model of power grids, and use local order parameters to describe local synchroniz ability. It shows that nodes with high power are difficult to locally synchronize to their direct neighbors. We propose a heterogeneous distribution method for network coupling strength. Keeping the total coupling strength, we increase coupling strength of links between high power nodes and their direct neighbor nodes, as well as links between other related nodes, and reduce coupling strength of links between the rest nodes. It shows that the method reduces critical synchronous coupling strength and improve synchronization performance in a certain range. As heterogeneity of the coupling strength is too great, synchronization performance of the network begins to deteriorate.

Liquid metal flow subject to a uniform magnetic field vertical to streamwise direction confined in a rectangular duct with 45° and 90° sudden expansion, and electrically conducting walls is numerically studied using magnetohydrodynamic (MHD) flow solver developed in OpenFOAM environment. Velocity distribution, induced electric current, pressure gradient and three-dimensional MHD effect are analyzed in detail. It shows that as external magnetic field is parallel to direction of duct expansion, velocity distribution is better in 45° sudden expansion duct than that in 90° expansion duct since there is no vortex at the expansion. With Hartmann number increasing, high velocity jets and intensive induced electric current cause a strong instability at the expansion. Instability grows to upstream of the expansion through induced electric current. As external magnetic field is vertical to expansion direction, induced electric current along streamwise direction is significant. With Hartmann number increasing, MHD pressure drop increases remarkably. Dimensionless pressure drop in fully developed duct is almost the same in different expansion duct as direction of applied magnetic field and Hartmann number are the same.

First-principles calculations based on density functional theory are performed for zinc-blende B_xGa_1-xAs alloy with a special quasirandom structure (SQS) approach in a 64-atom supercell. Structural,electronic and optical properties of B_xGa_1-xAs alloy are comprehensively investigated under optimized geometry structures. It was found that calculated lattice constant slightly deviated from Vegard's law and significant bond length relaxation is shown. Calculated bowing parameters of energy gap are small (2.57 eV-5.01 eV) and are weakly composition-dependent. Finally,effects of boron composition on optical parameters including dielectric function, reflectivity,refractive index,absorption coefficient and energy loss function are analyzed in detail.

Monte Carlo simulation for inverse Compton scattering in homogeneous isotropic media is studied. We analyze sample efficiency of rejection method that describes electronic speed and photon scattering direction. We also improve method of inverse functions for electron velocity distribution and composition-rejection methods for photon scattering energy distribution. We define application regime of these drawing methods by comparing their efficiency.

With potential energy surface constructed in 2003, we study stereodynamics of reaction Li+HF→LiF+H using quasiclassical trajectory (QCT) method. Polarization dependent differential cross sections (PDDCSs) and P(θ_r,φ_r) distributions describing k-k'-j' correlation related to collision energies. Vibrational states and rotational states are discussed at 1.15 kcal·mol^-1-5.0 kcal·mol^-1. Furthermore, cross sections are compared with that of other calculations and experiments. It indicates that vibrational and rotational excitations have stronger impacts on PDDCSs and P(θ_r,φ_r) than collision energy. Backscattering polarization of product rotational angular momentum is positive correlated with collision energy. Cross sections agree well with results of other theories and experiments in the range of calculation collision energies.

To study interpenetrating network hydrogel system of PAM/PVA, molecular dynamics simulation is made to investigate molecular interaction inside a hydrogel system. Effects of water content on PAM/PVA composite hydrogel performance are studied. It is found that cohesive energy density and binding energy of hydrogel system increase with water content increasing. Meanwhile elastic coefficients, engineering modulus and ductility decreased with increasing of water content. In addition, with analysis of pair correlation function, we found that there are mainly hydrogen bonding interactions between H₂O molecules and surrounding atoms or functional groups. Strengths of hydrogen bonds formed are O_water >O_PVA >O_PAM >N_PAM, which consists with possibility (difficulty) of forming hydrogen bond.

According to characteristic of shale gas reservoir,mathematical description methods of diffusion and desorption are analyzed.Three seepage models controlled by different kinds of seepage mechanisms are built:① a mathematical model which considers diffusion and interporosity of desorbed gas and free gas,② a mathematical model which considers desorption and diffusion,③ a mathematical model which considers desorption and diffusion in organic porosity and interporosity in inorganic porosity.With modified Lord Kelvin point source function pressure solutions are botained.With corresponding transformation for point source functions,formation pressure solutions for vertical fractured well and fractured horizontal well are obtained and typical curves are shown.At last,characteristics of different curves and three mechanisms' influences on pressure are analyzed.

Geometric structure of W_mB_n(m+n≤7) clusters are optimized by using density functional theory at B3LYP/LANL2DZ level. For ground state configurations, average binding energies, second order differential energies, energy gaps and WIB bond orders are analyzed. It shows that ground state structures of WB_n clusters are flat structures; as m≥2 and m+n≥4, all clusters are cube structure except W₃B cluster. Stability of clusters is getting better and better as W atoms increase. The bonding strength of W-W is significantly higher than those of W-B and B-B key. W atom plays a leading role in stability of clusters. Stability of W₂B₂ and W₃B cluster is the best.

Continuous-time random walk (CTRW) models with truncated power law waiting time distribution are investigated.Possible Monte Carlo algorithms to draw random numbers with such distribution are discussed.And an accurate rejection-acceptance method is proposed.Its sampling efficiency is greater than 80% as the power law exponent α > 0.2.Scaling relations of three types of anomalous transport arising in CTRW models are obtained.

An algorithm for pressure equation in a computational code PCCSAP-3 D,which is dedicated to analyze transient process of PCCS(Passive Containment Cooling System),is introduced.GMRES is introduced to accelerate calculation speed.Pre-conditioning of GMRES is applied.Convergence rates of GMRES and ML-ADI are compared.It shows that pre-conditioned GMRES can be used to solve pressure equations more efficiently.Since pressure equation coefficient matrix is structural and sparse,pre-conditioned GMRES is more efficient than ML-ADI as pressure equation coefficient matrix is larger.

The computation on the rate coefficient of electron ion collisional ionization is described and some fitting formulas are given for the accurate and fast calculation.

A approach of the calculation for the regular Coulomb wave function Ft (η,ρ) (η<0)and its main features depended on η,l and ρ are described. A example about their applications to integral calculations in electron-ion collision is given.