Journals
  Publication Years
  Keywords
Search within results Open Search
Please wait a minute...
For Selected: Toggle Thumbnails
Effect of Cu and Non-metal Double Acceptor Impurity Level Cooperative Action on Optical Properties of Anatase TiO2
CHEN Xiaoyu, FENG Qing, ZHOU Qing
CHINESE JOURNAL OF COMPUTATIONAL PHYSICS    2017, 34 (1): 99-108.  
Abstract450)   HTML0)    PDF (4182KB)(1917)      
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.
Reference | Related Articles | Metrics
A Numerical Study of Interactions Between Shock Waves and Flame with GPU Acceleration
JIANG Hua, DONG Gang, CHEN Xiao
CHINESE JOURNAL OF COMPUTATIONAL PHYSICS    2016, 33 (1): 23-29.  
Abstract337)   HTML0)    PDF (707KB)(1310)      
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.
Reference | Related Articles | Metrics
Lattice Boltzmann Model for Compound Burgers-Korteweg-de Vries Equation
DUAN Yali, CHEN Xianjin, KONG Linghua
CHINESE JOURNAL OF COMPUTATIONAL PHYSICS    2015, 32 (6): 639-648.  
Abstract481)      PDF (1536KB)(1234)      
We develop a lattice Boltzmann model for compound Burgers-Korteweg-de Vries (cBKdV) equation. By properly treating dispersive term uxxx and applying Chapman-Enskog expansion, the governing equation is recovered correctly from lattice Boltzmann equation and local equilibrium distribution functions are obtained. Numerical experiments show that our results agree well with exact solutions and have better numerical accuracy compared with previous numerical results. This hence indicates that the model is satisfactory and efficient.
Related Articles | Metrics
General Multiphase Matching for Grover Quantum Search Algorithm
JIN Wenliang, CHEN Xiangdong
CHINESE JOURNAL OF COMPUTATIONAL PHYSICS    2012, 29 (1): 152-158.  
Abstract410)      PDF (403KB)(980)      
Since a quantum system is inevitably influenced by some unpredictable perturbations, we thereby conclude that all the experimental realizations of Grover quantum search algorithm reported were, in fact, achieved in a three-dimensional complex subspace. We also prove that in a two-dimensional complex subspace, for any given initial superposition of basis states|γ0>=cosβ0|α>+sinβ0e|β)(β0 is a small positive real number, ζ is an arbitrary real number), there exists a set of solutions Fj={(θj,θj-1,…,θ1),(φj,φj-1,…,φ1)} such that a desired state can be found with certainty for some positive integer j≥2, where the phase rotation angles θl andθt are real numbers but not equal to 2k'π,1 ≤ 1 ≤ j,k'is an arbitrary integer. If it is only required that a desired state can be found with high success probability, then as the total number of the desired and undesired states in an unsorted database is sufficiently large the above set of solutions Fj can be written in the form  for a relatively small positive integer j.
Related Articles | Metrics
Numerical Simulation of Electric Field in Resistivity LWD Using High Accuracy Self-Adaptive hp-FEM
CHEN Xiaohui, LIU Dejun, MA Zhonghua
CHINESE JOURNAL OF COMPUTATIONAL PHYSICS    2011, 28 (1): 50-56.  
Abstract283)      PDF (818KB)(1413)      
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.
Related Articles | Metrics
Improved Ant Colony Optimization Algorithms for Ground State Energy of Quantum Mechanical Systems
CHEN Xia, TANG Chen
CHINESE JOURNAL OF COMPUTATIONAL PHYSICS    2010, 27 (4): 624-632.  
Abstract323)      PDF (390KB)(993)      
Ant colony optimization(ACO),a global optimization method,is proposed to analyze ground state energy of quantum mechanical systems.It simulates the way that real ants find a shortest path from nest to food source and back.In order to reduce iterations and improve solutions,ACO algorithm for ground state energy is modified.The proposed method exhibits advantage compared with traditional variation method.Ground state energy of helium atom and hydrogenic donors in GaAs-(Ga,Al)As quantum dot are calculated.The algorithm is demonstrated via comparison with variational method and genetic algorithms (GAs).
Related Articles | Metrics
Numerical Simulation of Mixed Convections
CHEN Xiaochun, LIN Guanjing, ZHOU Xiang, ZHU Yingxin, WANG Yuan
CHINESE JOURNAL OF COMPUTATIONAL PHYSICS    2007, 24 (1): 29-34.  
Abstract260)      PDF (402KB)(1103)      
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.
Related Articles | Metrics
SIMULATION CALCULATION OF SINGLE EVENT UPSET EFFECTS FOR HIGH ENERGY PROTONS
HE Chao-hui, CHEN Xiao-hua, LI Guo-zheng
CHINESE JOURNAL OF COMPUTATIONAL PHYSICS    2002, 19 (4): 367-371.  
Abstract280)      PDF (324KB)(1223)      
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.
Related Articles | Metrics
NUMERICAL MODELING OF POOL FIRES
WANG Jian, CHEN Xian-fu, DOBASHI Ristu, FAN Wei-cheng
CHINESE JOURNAL OF COMPUTATIONAL PHYSICS    2001, 18 (6): 523-526.  
Abstract231)      PDF (138KB)(1063)      
The numerical computation is often used to predict or study pool fires.The fluid flow,heat and mass transfer,chemical reaction and their interaction in the burning process are studied by formulating and solving a set of governing equations.The treatment of oil surface is given in details also.Many results of pool fires under various wind speeds are gained,and computational results are obtained.
Related Articles | Metrics
EQUIVALENT CIRCUITS SIMULATION FOR SINGLE EVENT GATE RUPTURE OF POWER MOSFETs
TANG Ben-qi, WANG Yian-ping, GEN Bin, CHEN Xiao-hua
CHINESE JOURNAL OF COMPUTATIONAL PHYSICS    2000, 17 (S1): 77-81.   DOI: 10.3969/j.issn.1001-246X.2000.01.014
Abstract321)      PDF (172KB)(1240)      
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.
Related Articles | Metrics
Calculations of overtones and com binations of ch 4 molecule using nonlinear quantum theory
Chen Xiangrong, Cheng Yan, Gou Qingquan, Pang Xiaofeng
CHINESE JOURNAL OF COMPUTATIONAL PHYSICS    1999, 16 (4): 346-350.  
Abstract220)      PDF (205KB)(974)      
A simple three-parameter dynamical model in nonlinear quantum theory-the quant ized discrete self trapping equation is used to calculate the highly excited vi brational spectrum of CH stretches of CH4 molecule with up to total quantum number n=7. The results show the model calculations appear to describe the expe rimental data well.
Related Articles | Metrics
The application of solid crystallization=process in optimization algorithm
Lu Wei, Tao Fengxiang, Mu Yaoming, Chen Xiaoshuang, Li Ning, Liu Xingquan, Liu Jingjiao, Shen Xuechu, Lu Hong
CHINESE JOURNAL OF COMPUTATIONAL PHYSICS    1999, 16 (2): 141-144.  
Abstract260)      PDF (164KB)(1125)      
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.
Related Articles | Metrics
NUMERICAL SIMULATION OF OIL-WELL PERFORATOR
Hang Yihong, Chen Xianlin, Dong Zhen, Yu Zhilu, Fan Zhongbo, Geng Hunan
CHINESE JOURNAL OF COMPUTATIONAL PHYSICS    1997, 14 (S1): 404-406.  
Abstract227)      PDF (173KB)(953)      
A hybrid computational method and the corresponding software for simulating oil well perforator are described.A good agreement has been obtained between computational results and experiments.This research indicates that the software has a higher ratio of effectiveness over cost.
Related Articles | Metrics
MATHELDCA-A MATHEMATICA PROGRAM FOR CALCULATING ONE LOOP FEYNMAN DIAGRAMS WITH AMPLITUDES
Ma Wengan, Sun Lazhen, Chen Xiaoxi, Qian Minglun
CHINESE JOURNAL OF COMPUTATIONAL PHYSICS    1994, 11 (1): 123-128.  
Abstract628)      PDF (342KB)(1220)      
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.
Related Articles | Metrics
A RADIANT TEMPERATURE NUMERICAL METHOD FORLASER-PLASMA DIAGNOSTIC USING SXRSCWITH ABSORPTION METHOD
Tang Yongjian, Ding Yiaonan, Zheng Zhijian, Chen Xiaofeng
CHINESE JOURNAL OF COMPUTATIONAL PHYSICS    1990, 7 (3): 268-274.  
Abstract264)      PDF (403KB)(1018)      
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.
Related Articles | Metrics
APROXIMATE SOLUTION OF IHE IONIZATION DEGREES FOR HIGH TEMPERATURE GASES
Chen Dong-quan, Chen Xiang-tao
CHINESE JOURNAL OF COMPUTATIONAL PHYSICS    1985, 2 (2): 148-160.  
Abstract268)      PDF (695KB)(1171)      
This Paper Presents an approximate method of calculating the ianization degrees, and then an analytic expression of the equation of state for high temperature gases is derived, which can be applied directly to the fluid dynamics calculations. The expression is simple and Its results are fairly accurate.
Related Articles | Metrics