Density functional theory was employed to explore adsorption mechanism of benzoic acid and toluene molecules on calcite surface, and to analyze influence of polarity on the adsorption. It showed that benzoic acid was tilted adsorbed on CaCO₃(104) surface in the form of undissociated molecules and in monodentate mode, while toluene was parallel adsorbed. Geometrical structure of organic molecules changed significantly during the adsorption, in which the deformation of benzoic acid was much greater than that of toluene. Meanwhile, electronic structure of the adsorption system was also changed. During the adsorption of benzoic acid, Ca-O ionic bond and H-O covalent bond were formed. However, there was only weak hydrogen bond between toluene and CaCO₃(104) surface. Obviously, adsorption intensity of benzoic acid (polar molecule) on CaCO₃(104) surface is greater than that of toluene (non-polar molecule). It provided theoretical support for EOR and mineral flotation engineering.

We studied adsorption characteristics of oil-water system on calcite and dolomite surface with molecular dynamic simulation. To study wettability of calcite/dolomite surfaces, we analyzed equilibrium conformation, relative concentration, radial distribution function and adsorption energy of calcite/dolomite-oil/water system. Then, we proposed a two-step adsorption mechanism. It shows that dolomite-oil/water system is more easily to achieve thermodynamic stability and is more stable; A water film is formed on calcite and dolomite surfaces, which is a double-layer structure; There are interactions among oil molecules, water molecules and the crystal surface; Attraction of dolomite surface to oil and water molecules is stronger than calcite. Finally, we divided the adsorption process into two steps:Water molecules adsorbed on crystal surfaces form a tightly adsorbed layer under van der Waals forces, electrostatic forces and O(CaCO₃,CaMg(CO₃)₂)-H(H₂O) hydrogen bonds. In addition, the remaining water molecules move to the crystal surface form a diffusion layer under the influence of O(H₂O)-H(H₂O) hydrogen bonds. It reveals wettability formation and alteration mechanisms on calcite and dolomite surface, which paves a foundation of further enhance oil reovery.

Based on study of sound propagation characteristics in periodic tube array, we investigate acoustic radiation characteristics in power station tube arrays. The heat exchanger structure in boiler is similar to phononic crystal. Different location in tube arrays acoustic radiation characteristics is studied. It shows that acoustic radiation directivity not only have relation with tube row number, but also have relation with frequency in acoustic band gap.

To study heat and mass transfer around pulverized coal particle under high intensity acoustic field with superposed steady component, two-dimensional, unsteady, laminar conservation equations for mass, momentum and energy transport in flue gas phase of power plant boiler were developed. Local Nusselt, space-averaged Nusselt and space- and time-averaged Nusselt numbers around coal particles, as functions of sound pressure level, frequency and ratio of acoustic velocity to steady slip velocity between particles and main flow, were discussed. There exists extremum frequency in which heat and mass transfer effect is the best in the range of audible sound frequency. It highlights a good application prospect in combustion for boiler.

To study flow field distribution characteristics around a pulverized coal particle in high intensity acoustic field with sonic frequencies, two-dimensional unsteady mass and momentum conservations for laminar flow in spherical coordinates were developed with actual parameters of power plant boiler. Displacement amplitude of incident sound wave is greater than characteristic length of particles, and acoustic Reynolds number is less than 20. Velocity field, axial pressure gradient, shear stress and flow separation angle around particle were analyzed at different acoustic Reynolds numbers and Strouhal numbers. It is found that axial pressure gradient, shear stress and separation angle are proportional to magnitude of sound at low frequency (~50Hz). However, they are different due to combined effects of curvature and flow acceleration at high frequency (~5 000 Hz). It provides theoretical foundation for further research on acoustic enhancement of heat and mass transfer in power plant boiler.

With dynamic coupling model of fractured anisotropic full-tensor permeability, a complete three-dimensional three-phase fluid-solid coupling model for anisotropic ultra-low permeability reservoir is established. Using modular explicit coupling iteration, we establish a fluid & solid coupling seepage numerical simulation method considering fracture deformation and corresponding coupling program. It shows that for fractured reservoir, with change of reservoir pressure in process of mining, rock deformation and anisotropy of reservoir medium strain can make various deformation degree in multiple sets of cracks, cause nonlinear change of fracture permeability, which makes principal value of reservoir fracture permeability tensor rotating, changing flow direction, affecting reservoir development effect.

A model of sheath formation on a planar electrode in strongly electronegative plasmas is presented.The plasma sheath is studied by using a set of hydrodynamic equations.Spatial potential,net space charge distributions and sheath width as functions of distance are obtained.It shows that in a strongly electronegative sheath a presheath between bulk plasma and sheath hardly exist,and electrons,negative and positive ions in the sheath form a pure positive ion sheath near boundary of electrode.Density of net space charge has a sharp peak near the sheath edge.Compared with an electropositive sheath,it is found that the width of strongly electronegative sheath is much narrower,and the spatial potential within the sheath falls much faster.

A relaxation algorithm is developed to simulate sphere packing with arbitrary diameter distribution.An adaptive iteration period is employed to keep the packing density stable with various number of spheres.The packing density and the coordinate number of the algorithm are higher than those of previous approaches.The efficiency of contact detection is considerably increased by background grids and double link group structure.The time complexity of the algorithm is O(N),where N is the number of spheres.It needs only CPU time of 217s to achieve a packing density of 0.64 for random close packing of 10 000 equal spheres with an AMD Athlon 3200+PC.New classification of numerical methods for sphere packing is also presented.

A model for flow in a 3-dimensional 3-phase anisotropic oil reservoir is established and applied to reservoir development.The model includes a complete anisotropic permeability tensor.It characterizes the anisotropic permeability distribution with different principal directions in different regions.It calculates the fluid flow,the residual oil distribution and the pressure distribution in anisotropic reservoirs accurately.

Treanor's and Gear's methods are applied to chemical reactions in the process of NO_x/SO₂ removal. The results are satisfactory. The systems of NO-NO₂-N₂,NO-NO₂-N₂-O₂ and NO-NO₂-N₂-O₂-H₂O are discussed. The removal of NO_x and SO₂ is also discussed as CO₂ and SO₂ are added.

The numerical simulation of lattice Boltzmann method (LBM) is one of the most efficient methods to investigate the complex porous media structure, particularly the Klinkenberg effect. It is very useful to deal with the related complex boundary problems.The problems of gas flow through porous media are studied by using the lattice Boltzmann methods. Comparison between the numerical simulation results and the experimental results is carried out. It is shown that the lattice Boltzmamn method is one of the most efficient methods to simulate the problems of gas flow through complex porous media.

Electron energy distributions of direct-curent argon discharges at low pressures were calculated by numerically solving the homogeneous Baltzmann equation. The calculations cover the whole range of low electron densities to sufficiently high electron densities. Typical values of the ratios of the electric field to the gas density in this work are in the renges of 10^-16 < E/N < 10^-15 Vcm². The influence of electron-electron collisions and the electric field on the electron energy distribution function was studied.

This paper presents a numerical method for solving the two-dimensional long-wave equations given by [1],Since the method needn't treat the integral on the boundary, not only the amount of data preparations on the numerical computation is reduced, the computing, time is shortened, the computing error is lowered, but also the interference of the short-wave noise cited in [2] does not appear.The M₂ component tide in the Bohai Sea is calculated by the method give in this paper. It is more satisfacting that the calculated result coincided with the observed data.