As a high-temperature phase of Pu, δ-Pu doped with little Ga can stay to room temperature. Crystal structure and electronic structure of systems with different contents of Ga are calculated with density functional theory (DFT) method. Calculations mainly include lattice constant, density, formation energy, density of states(DOS), electron density and Mulliken population. It shows that within studied doping scope, lattice constant of systems decrease and density of systems increase with increase of content of Ga, while stability of system with 6.25% content of Ga is superior to that with 3.125% and 12.5% content of Ga. Ga-doping enhanced locality and strengthens bonding ability of electrons, which, to some degree, reveals electronic mechanism of Ga stabilizing δ-Pu. Character of Pu-Ga bond is metallic state, and interaction is mainly contributed by Pu 7s, 6p, 6d and Ga 4s, 4p orbital electrons. While interaction is relatively weak, doped systems maintain fine mechanical properties and machining performance. Contribution of Ga to stability of δ-Pu lies mainly in its improvement on bonding performance of Pu, instead of its immediate bonding effect with Pu.

Density functional theory with B3LYP functionals was used to study generating phenanthrene derivatives mechanism of acetylenic-keton intramolecular cyclization reaction catalyzed by AuCl₃. It shows that the reaction can occur through [2+2] and [2+6] reaction pathways with and without AuCl₃ catalyst. Without catalyst, energy barrier of rate determining step of [2+2] pathway is lower than that of [2+6] pathway by 32.01 kJ·mol^-1. Reaction mainly occurs through [2+2] pathway. With AuCl₃ catalyst, dominent reaction pathway is still [2+2] pathway with an energy barrier of rate determining step of 137.05 kJ·mol^-1. Energy barrier of rate determining step of four-membered ring pathway with AuCl₃ catalyst is 102.72 kJ·mol^-1 lower than that of reaction without catalyst. This difference indicates that AuCl₃ is an efficient catalyst which can raise reaction rate and moderate reaction condition.

With computational fluid dynamics method, effect of embankment inclining angle on aerodynamic characteristics of high speed train under crosswinds is explored. It shows that as inclining angle of embankment is increased, side force coefficient on head train is increased a little and then decreased. Side force coefficient on middle train is gradually decreased. Side force coefficient on rear train is decreased a little and then increased as the angle reaches 47.5°. Negative lifting force coefficient on middle train is increased and lifting force coefficient on rear train is sensitive to inclining angle of embankment. The flow field around train is transformed as the inclining angle of embankment is changed and aerodynamic force or moment is changed consequently.

Numerical radiograph using Monte Carlo method is used to study fidelity of density reconstruction in high. energy X-ray radiography.A density reconstruction method for a polyenergetic X-ray source and an object composed of different materials is proposed.The method includes energy spectrum,angular spectrum and spot size of photon source. And it indudes mass absorption coefficients explicitly in density reconstruction as well.A constrained conjugate gradient algorithm and variation regularization are applied to determine material edges and density reconstruction of a French test object.It shows that the method is valid for density reconstruction and energy spectrum of imaging photons is important in obtaining accurate material densities in high-energy X-ray radiography.