We carried out first-principles calculations of Li (110), (100) and (111) free-standing thin films from 3 to 30 monolayers to study oscillatory quantum size effects exhibited in surface energy, adsorption energy of hydrogen atoms. Furthermore, we investigated adsorption height of hydrogen atom, density of states at Fermi level and work function of Li (110) thin films. Calculated physical quantities feature clearly quantum oscillations as functions of film thickness, which is also called quantum size effects. Calculated results show clearly quantum oscillations in adsorption energetics, which can be used to modulate chemical reactivity and other surface process in nanostructure materials. Finally, calculated results show clearly that work function of Li (110) films is reduced about 0.9 eV by adsorption of hydrogen atoms. Adsorbed hydrogen atoms cut down electrostatic potential of Li atoms on the outermost layer and vacuum layer, resulting in decrease of work function with adsorption of hydrogen atoms.

Direct numerical simulations of binary electrolyte in an electrode channel with turbulent mass transfer are performed under limiting current condition and galvanostatic current conditions. Behaviors of turbulent concentration diffusion from electrodes to adjacent electrolyte in a wide range of Schmidt numbers are examined and mechanism of turbulent mass transfer in electrolytic processes is analyzed. A physical model for turbulent electrodes channel flow is established with electrochemistry theories as well as fluid dynamics. Effect of Schmidt numbers on turbulent mass transport, mean and fluctuating concentrations, mass transfer coefficient, Sherwood numbers, and instantaneous structures of concentration fields are exhibited and analyzed. It shows that mass transfer at electrodes in turbulent electrolyte is sensitive to current conditions.

According to the characteristics of compressible flows with wall boundary conditions, a simplified iterative-implicit timeadvancement scheme combined with high order compact difference schemes based on a non-uniform grid system is proposed to solve compressible Navier-Stokes equations, An iteration convergence criterion is given. The computational efficiency is greatly improved. The new scheme is applied to simulate two-dimensional compressible flat-plat laminar boundary layer flows and two-dimensional compressible channel flows.

A v'²-f model,a k-ε model and an indoor zero equation model are adopted respectively to simulate mixed convections which are typical in ventilation and air conditioning systems.It indicates that there is a separated vortex near the ventilation inlet,and the accuracy for predicting this vortex is a critical factor in the simulation.The separated vortex dimension obtained by experiments is between the values calculated by the v'²-f model and the indoor zero equation model,while the dimension predicted by the k-ε model is a bit smaller.The results predicted by the indoor zero equation fit experimental results best.However,it is not in general from the view of model structure.For calculating temperature field the v'²-f model is better than the indoor zero equation model,and the k-ε model is the worst among the three.

A Wavelet Interpolating Galerkin Method (WIGM) for elliptic partial differential equations,especially in irregular regions,is considered.It is proved that the WIGM produces an approximation with an error no more than C2^-m in the Sobolev space norm.A numerical WIGM algorithm for static electromagnetic field analysis in irregular regions is presented.A symmetric interpolating scaling function is selected as the base function.Its symmetry and relation with average-interpolating scaling function are used to reduce numerical computations.Examples presented demonstrate validity of the algorithm.

By means of a complete configuration mixing unified crystal field theory for d⁸(D_4h^*),the optical spectra,the ground state ZFS,EPS parameters,the ground state paramagnetic susceptibility and the magnetization of the Ni(mpz)₄Cl₂ compounds are analysed and calculated systematically.Numerical results agree well with the experimental data,so a complete and reasonable explanation is provicled for the magnetic of Ni(mpz)₄Cl₂ compounds.

In this paper, a method to reduce the virtual gravity waves in numerical model is proposed. An experiment of a case using this method is carried out. The result shows that the "noise" is weaken not only in the initial field but also also in the computational processes, and the simulated results are improved.