With first-principles plane-wave ultrasoft pseudopotential method based on density functional theory (DFT), we studied acceptor level characreristics of anatase titanium dioxide doped and co-doped with 3d metal impurities Cu and non-metallic impurities C, N and F.It shows that Cu-N co-doping system and Cu, N single-doped system are better for visible light.Cu-N co-doping system, compared with Cu, N single-doped system, has a smaller band gap and greater density distribution on shallow acceptor level.It also shows that Cu-N co-doping system has highest absorption and reflectivity.Therefore, this system is the best for visible light.Cu and N acceptor level cooperative action results in the best visible light effect.

To study performance of graphic processing unit (GPU) for computational fluid dynamics, simulation on interactions between shock waves and a flame interface, a typical compressible reactive flow, was carried out on CPU/GPU heterogeneous system. Several optimal strategies are taken to raise GPU code performance. Computational results and acceleration performance of GPU with different grid number were examined. It was found that computational results by parallel GPU are the same as those by traditional CPU based on MPI parallel of 8 threads. Computational times of two parallel methods linearly grow with increase of computational grid numbers. Compuational cost by GPU is less than cost by MPI. As grid number is small(1.6×10⁴), speedup ratio of 8. 6 was achieved on GPU. As grid number grows, speedup ratio decreases. However, a ratio of 5.9 still can be held on GPU when grid number is more (4.2×10⁶). Arithmetic on CPU/GPU heterogeneous system provides a good solution for large-scale computations of compressible reactive flows.

A high accuracy self-adaptive hp-finite element method(FEM) is used to simulate resistivity logging-while-drilling(LWD) electric field distribution.The algorithm can choose optimal refinement and calculation strategy according to practical formation model and error estimation.Accurate approximations of electrical field can be obtained without an accurate solution in the entire computational domain.Self-adaptive hp-FEM method has an exponential convergence rate.It indicates that voltage phase difference and amplitude ratio curves between receiver coils are well matched with the layer model.It is helpful to interpretate resistivity LWD data.

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 model and a simulating method for calculating the proton Single Event Upset (SEU) cross section are presented by the analysis of proton reactions in silicon. The energies deposited by protons of various energies are calculated in sensitive volume in memory cell. It is pro posed that high energy proton SEU is greatly attributed to the recoils (heavy ions), produced by proton reactions in silicon, which deposit ener gy and induce charge in sensitive volume. The relations of the SEU cross section vs. proton energy and critical charge have been obtained. The calculation results are in agreement with the experimental data.

A new model is established to perform simulation for Single-Event Gate-Rupture of power MOSFETs in use of PSPICE circuit simulation software. The application results have a very good agreement with the corresponding data in published articles.

It investigates the application of solid crystallization process in the optimization algorithm.A special way is also proposed for the parameter "stirring" for the target function to get minimum value of the target function in the whole parameters' region.Meanwhile,the optimization algorithm is independent on the initial value of parameters without the larger calculation time.

Using Mathematica symbalic manipulation system, the computer program MATHELDCA is developed for calculating one loop Feynman diagrams in renormalizable gauge theories. It is only needed to input the amplitudes of contributed diagrams according to the Feynman rule, so as to calculate the radiative corrections of particle process.

An numerical method was developed for measuring radiant temperature using a set of absorption-foils coupled to soft x ray streak camera, SXRSC, in laser plasma experiments. An numerical code, SCC, was given. An x-ray intensity ratio vs temperature was calculated for Parylene, C₃H₆, Formvar, Mylar and Aluminum. A suitable range of the measuring temperature was discussed to some absorber.