A transfer matrix method is used to analytical calculation formulas of photonic band and equifrequency surface of one-dimensional Fibonacci sequence photonic crystal. Analytical physical quantities such as equivalent phase refractive index, group velocity and wave vector are given. Dispersion relations of this kind one-dimensional photonic crystal are studied contrastively with formulas and finite difference time domain method. It shows that results obtained by numerical method and analytical method are consistent with each other in overall trend. However, in weakly modulated one-dimensional photonic crystal, fatal error was made in numerical calculation result of equifrequency surfaces. Therefore, numerical results of weakly modulated photonic crystals must be verified with other methods such as analytical calculation or numerical simulation.

A multiscale deep learning model is proposed for fluid flow in porous media. The method is formulated on hierarchical grid system, that is, a coarse grid and a fine grid. Deep learning network is used to train data on the coarse gird. Source term and permeability field is treated as input parameter and coarse-scale solution is treated as output parameter. We construct multiscale basis functions by solving local flow problems within coarse gridcells. Heterogeneity and interactions between matrix and fracture are captured by basis functions. Oversampling technique is applied to get more accurate small-scale details. Numerical experiments show that the multiscale deep learning model is promising for flow simulation in heterogeneous and fractured porous media.

Conduction band structure of silicon under uniaxial[110] stress is studied with two band k·p perturbation theory. Splitting energy of conduction band minima and electron effective mass as a function of stress and direction electron mobility in uniaxial stressed silicon are obtained with relax time approximate theory. Intervalley scattering, intravalley scattering, and ionized impurity scattering are considered in calculation. It is demonstrated that as uniaxial[110] stress is applied on silicon crystal, a significant anisotropy in electron mobility can be observed. Among crystal directions[001],[110], and[110], electron mobility along[110] direction under uniaxial[110] tensile stress has a profound enhancement, which increase from 1 450 cm²·Vs^-1 to 2 500 cm²·Vs^-1 as stress change from 0 to 2 GPa. Electron mobility enhancement is mainly due to uniaxial stress induced conduction effective mass reduction, while suppression of intervalley scattering plays a minor role.

Considering complexity of coupled fluid-solid calculation of low supersonic aircraft under unsteady flight condition, real time aerodynamic heat by outer fluid field is converted into floated third type boundary conditions for decoupled calculation. Take three-dimensional head cone experiencing accelerating diving as example, floated temperature and radiation equilibrium methods are adopted to extract surface heat transfer coefficients for decoupling calculation. Results are compared with coupled results to validate reliability of decoupling methods. It shows that with dispersed state points representing unsteady process, temperature distributions of cone surface at different state points by decoupling methods agree well with coupling ones. Calculating efficiency of decoupling methods is superior to coupling ones. Maximum relative errors of decoupling methods are both within 2%, even as external aerodynamic environment changes dramatically.

Equilibrium geometries,electronic and magnetic properties of M_n(SiO₂)₃(M= Fe,Co,Ni;n=1-3) clusters are systematically studied employing density functional theory with a generalized gradient approximation. It shows that Fe and Co atoms are easier to congregate on (SiO₂)₃ cluster than Ni atoms. It is found that stabler silica is an excellent matrix materials to carry islands of transition-metals. Energy gaps of M_n(SiO₂)₃(M=Fe,Co,Ni;n=1-3) clusters lie in near infrared radiation region. In analysis of magnetism,it is found that their magnetic moments are mainly located on transition-metal atoms. Fe₂(SiO₂)₃ and Co₃(SiO₂)₃ have greater magnetic moments,owing to coupling between d orbits of transition-metal atoms. Energy gap and magnetic property affirm a considerable foreground of magnetic-mulriple silica used for photodynamic target therapy in medical stage.

Disturbance equations of velocity and temperature fields are built based on Boussinesq approximation,in which second order and higher-order disturbance of Bénard convection are ignored. Transcendental equations controlling Bénard convection are obtained with non-dimensional treatment of variables. Specific parameters of Bénard convection are obtained,which provide reference and guidance for Bénard convection experiments.

Possible equilibrium geometries of W_nNi_m(n+m=8) clusters are optimized with density functional theory at B3LYP/LANL2DZ level.For ground state structures,molecular orbital energy level,HOMO level,LUMO level,aromaticity and thermodynamics are analyzed.It shows that molecular orbits between Alpha and Beta in clusters W₅Ni₃ and W₆Ni₂ are completely degenerate,and all electrons are strictly paired.W₂Ni₆ cluster,with low energy gap,has strong chemical activity.Its component for frontier orbital are basically the same.W₆Ni₂cluster,with high energy gap,has weak chemical activity;Clusters W₁Ni₇,W₅Ni₃,W₆Ni₂,W₇Ni₁ have aromaticity,while W₂Ni₆ cluster has antiaromaticity.Formation enthalpy of all clusters W_nNi_m(n+m=8) are negative.They are stable Oil thermodynamics.

To investigate mechanism of TUDOG(transeverse uniform singlet oxygen generator),a chemical reaction model is made to describe physical and chemical performances of Cl₂/He mixed gases transversely traveling into a falling BHP(KOH,H₂O₂,H₂O)drop field.Numerical computation is carried out.In two-phase flows,exchange of mass and momentum between two phases is considered.One set of 2-D gas-phase flow equations are solved with SIMPLEC scheme.Simulation results agree well with experiments provided in references.It is found that chlorine utility and singlet oxygen yield decreases with increase of gaseous inflow speed,and increases with speed of falling drops.Absorb and utility of chlorine mainly takes place in reactive region upstream.

Possible equilibrium geometries of W_nC^0,±(n=1,…,6) clusters are optimized with density functional theory at B3LYP/LANL2DZ level.Stability and electronic properties of ground state structures are analyzed.It shows that as n > 3 cluster undergoes a transition from a two-dimensional structure to a three-dimensional structure,and carbon atom remains on the surface of cluster.Stability of W_n cluster is increased with doped carbon atom.Moreover W₃C is the most stable one among W_nC^0,±(n=1,…,6) clusters,and it is taken as a basic structure.Electronic properties of W_nC^0,±(n=1,…,6) clusters are characterized by analyzing energy gaps,vertical electron affinities(VEA) and vertical ionization potentials(VIP) of W_nC with pure Wnclusters.W_nC clusters get electron easily and shows higher nonmetallicity than W_n clusters.

In semiclassical rescattering model,momentum distribution of recoil ions,momentum correlation of two ejected electrons and ionized energy of tunnelled electron are calculated as molecular orientation is parallel or perpendicular to the linearly polarized field.It indicates that molecular orientation and laser intensity have strong impacts on non-sequential double ionization.

For a Fibonacci chain constructed recursively with S_m+1={S_m|S_m-1}, in a tight-binding model of single electron, we investigate numerically density of electronic states and electronic energy band structure with negative eigenvalue theory and three diagonally symmetric matrixes. Trifurcating structure of energy band of the system is demonstrated. With renormalization-group method and scattering theory, we study localization length and transmission coefficients of electronic states in a chain. At particular eigen-energies, extend states with localization lengths greater than size of the system are found and transmission coefficient is equal nearly to 1. At most eigen-energies, corresponding electronic states are localized states due to short localization length. In addition, relations between transmission coefficients and parameters of Fibonacci chain are qualitatively investigated.

A rigorous Boltzmann equation analysis for calculating electron swarm parameters of gases for the SST, PT and TOF experiments is introduced. The calculated swarm parameters for SF₆ and N₂ at E/N values from 169×10^-21(V°m²) to 424×10^-21(V°m²) are in good agreement with the measured parameters.

A gas-phase elementary-reaction mechanism of diamond growth by a vapor depostion process is proposed. The rate constants for-all reactions included in the model have been computed using the species and their transition-state parameters predicted by molecular orbital ab intio at HF/6-31G^* level The calculated results quantitatively agree with experimental data on the concentration of gas-phase species and substrate temperature.

The value of potential barrier of H abstraction from hydrogeneted diamond (111) surface is critical to understand nucleation and growth dynamics of diamond film under the condition of Chemical Vapor Deposition.The previous theoretical works on the value are far from accord based upon different MO methods.On use of a series of cluster models and some kinds of MO methods the potential barrier is systematically studied here.After determinating the MNDO approach reliability for this problem,the corrected theoretical value is given as well.

The potential energy curves between methyl and diamond (Ⅲ) surface are calculated by Ami semi-empirical molecular orbital method, which are found to be in close agreement with the substrate models. It provides much information for studying the dynamic processes of the nucleation and growth of diamond films, and more general adsorption as well.

This paper presents a variable multigroup method for calculation in non-equilibrium radiative transfer considered atomic line cross section shift. The use of this method coupling with the conventional multigroup method is descrived and compared with the latter for simple example.

With regard to evaluation of auxiliary function I_μ(x)up to arbitrary accuracy, it is required that the forward recurrence scheme of the function can be used as far as possible. Applying a new inequality found by us, we have set up a criterion which can accurately decide whether the requirement can be met.

Two inequalities of incomplete Gamma function are given for the domain v∈[0,-∞) and z∈(-∞,0].Based upon the inequalities, we derive the round off error propagation regularity of the forward recurrence scheme. Our numerical experiments indicate that the relative error predicated by our regularity almost coincides with that from authentic regularity in the whole domain of v and z.

The formulae of two-electron integrals are optimized by using complex Slater orbitals. Analysing both the formula structure and the instability of auxiliary functions, we obtain some approximate conditions of realizing the best balance between the required accuracy and the computational speed.