激光散斑引起象强度中心漂移的计算机模拟

本文对这个基本不确定度进行了计算机模拟研究，所得模拟曲线与Ｒ．Ｇ．Ｄｏｒｓｃｈ，Ｇ．Ｈａｕｓｌｅｒ等人的研究基本一致。此外，还对基本不确定度与表面粗糙度的关系，基本不确定度与成象系统点扩散函数内所包含的相关单元的关系进行了研究。     

金属纳米粒子氧化行为的计算机模拟研究进展

金属纳米粒子在新材料研究领域中有着广泛的应用。人们对金属纳米粒子的氧化行为通过理论和实验进行了深入的研究,其中计算机模拟研究是非常重要的方法。本文简要介绍了微观尺度层次上的计算机模拟方法,在此基础上综述了国内外金属纳米粒子氧化行为的计算机模拟研究进展。     

溅射与沉积过程的计算机模拟

应用TRIM和TRIDYN程序模拟氮化硼材料的溅射率与Ar 入射角的关系，Ar 辅助沉积氮化础薄膜与硅基片的界面结构，铜基片溅射率与入射能量的关系，以及Ar 以垂直于表面方向轰击非晶硅产生的溅射速率。铜基片溅射率的计算结果与已有的实验数据相比较表明，两者吻合得很好。硅片的溅射速率与应用38－cm宽束离子源设备的实验结果之间也吻合比较好。     

Monte-Carlo program MODEX: Simulation of point defect clustering during irradiation and subsequent annealing

A Monte Carlo program MODEX is presented, capable of simulating the defect clustering process during ion implantation and subsequent annealing. The program considers four different types of point defects, e.g. implanted ions, vacancies, self-interstitials and impurities, as mobile. Depending on the mobility of the point defect the diffusion equations are solved in the stationary or non-stationary form. The clustering process of point defects is described by a set of rate equations and is simulated through a number of elementary trapping and dissociation events. The use of the program is demonstrated in examples of helium implantation in molybdenum, vanadium and silicon and the simulation results are discussed in relation to the results of helium desorption experiments.     

低能电子投射全息的计算机模拟和数值重现研究

点源发出的低能量电子波经过样品的散射后,带有物体原子结构信息的散射波(物波)和未被散射的电子波(参考波)在收集平面上相互干涉形成的电子全息图即为低能电子投射全息图.本文在合理的物理模型下,以石墨的晶体结构为试样,通过计算机模拟的方法,首次对低能电子投射全息进行了研究,讨论了一些关键参数对晶体结构电子全息的重现像和分辨率的影响,并且实现了晶体结构三维数值重现,讨论了三维重现的效果.     

Computer Simulation of the Indentation Creep Tests on Particle-Reinforced Composites

A systematical simulation has been carried out on the indentation creep test on particle-reinforced composites.The deformation ,failure mechanisms and life are analyzed by three reasonable models.The following five factors have been considered simultaneously:creep property of the particle,creep property of the matrix,the shape of the particle, the volume faction of the particle and the size(relative size to the particle )of the indentation indenter.For all the cases,the power law respecting to the applied stress can be used to model the steady indentation creep depth rate of the indenter,and the detail expressions have been presented.The computer simulation is analyzed by the two-phase model and the three-phase model.Two places of the stress concentration are found in the composites.One is ahead of the indentation indenter, where the high stress state is deduced by the edge of theindenter and will decrease rapidly near to a steady value with the creep time The other one is at the interface,where the high stress state is deduced by the misfit of material properties between the particles and matrix.It has been found that the creep dissipation energy density other than a stress parameter can be used to be the criterion to model the debonding of the interfaces.With the criterion of the critical creep dissipation energy density, a power law to the applied stress with negative exponent can be used to model the failure life deduced by the debonding of interfaces.The influences of the shape of the particles and the matching of creep properties of particle and matrix can be discussed for the failure.With a crack model,the further growthe of interface crack is analyzed, and some important experimental phenomena can be predicted.The failure mechanism which the particle will be punched into matrix has been also discussed.The critical differences between the creep properties of the particles and matrix have been calculated, after a parameter has been defined.In the view of competition of failure mechanisms, the best matching of the creep properties of the two phases and the best shape of the particles are discussed for the composite design.     

圆锥形阴极真空微三极管的计算机模拟

利用有限元法对圆锥形场致发射阴极的真空微三极管进行了计算机模拟。改变真空微三极管的各项结构参数及阳极和栅极电压 ,得到一系列模拟数据。然后对模拟结果进行分析讨论 ,总结出圆锥形阴极有效发射、阳极电流与真空微三极管的结构尺寸、阳极电压和栅极电压之间的关系 ,对于真空微三极管的实际设计和制作有一定的参考价值     

玻璃熔窑数值模拟的计算方法和计算机语言的使用

本文阐述了在玻璃熔窑数值模拟过程中所采用的几种方法，比较了各种方法的优缺点，并且介绍了模拟所采用的各种不同语言。对方法和语言的使用进行了分析，提出了看法。     

SMT印刷电路板组件脆值的计算机仿真分析系统探讨

针对一种典型的电子产品－－ＳＭＴ印刷电路板组件,提出了一种非破坏性的脆值评价方法,即采用计算机仿真技术进行分析。     

球床高温气冷堆物理特性的计算机模拟

为研究球床高温气冷堆的物理特性，研制出了一套完整的计算机模拟方法和相应的物理计算程序系统。该方法的特点是：考虑了包覆颗粒球粒球型燃料元件的双重非均匀性和燃料元件的运动特性；通处理复杂的堆内外燃料管理；考虑了堆芯顶部装料空间；在谱计算中采用了曲率反馈，并能进行物理和热工计算的直接耦合，该方法已用于ＨＴＲ－１０实验堆的物理设计。     

大型齿圈淬火温度场计算机模拟及畸变控制

通过ANSYS模拟软件对大型渗碳齿圈淬火冷却过程进行计算机模拟,得到了齿圈淬火时温度场的动态分布,进而求出齿圈和工装在塑性温度区的最大温差。利用该温差,运用金属材料的高温塑性及相变塑性理论,设计特殊的工装,使齿圈在二次淬火的同时能够自行修正渗碳时造成的椭圆,达到整圆和防止椭圆的目的,可以省去热处理后压力校圆工序。与常规的淬火后再进行压力校圆的方法相比,该方法畸变量小、生产质量稳定、工艺效率高、成本低,而且避免了热处理后校圆开裂现象。     

微观偏析建模与仿真的研究进展

微观偏析数值模拟是材料成形过程数值模拟研究的一个重要分支。论述了微观偏析数值模拟研究的重要性和研究进展。分析了晶粒域微观偏析模型和界面域微观偏析模型的建模思想、各自特点及其与相关模型的耦合方法。指出了当前微观偏析数值模拟研究中存在的问题，展望了这一领域未来的研究前景和发展方向。     

机电产品缓冲包装的计算机动态仿真系统的探索

通过对缓冲包装系统在正弦位移激励和冲击力作用下的动态分析，建立了缓冲包装的计算机动态仿真、性能评价及其设计的一体化系统。     

Modeling and simulation of curing kinetics for the cardanol-based vinyl ester resin by means of non-isothermal DSC measurements

The cure kinetics of vinyl ester-styrene system was studied by non-isothermal differential scanning calorimetric (DSC) technique at four different heating rates. The kinetic parameters of the curing process were determined by isoconversional method for the kinetic analysis of the data obtained by the thermal treatment. Activation energy (E_a = 56.63 kJ mol⁻¹) was evaluated for the cure process and a two-parameter (m, n) autocatalytic model was found to be the most adequate to describe the cure kinetics of the studied cardanol-based vinyl ester resin. Non-isothermal DSC curves, as obtained by using the experimental data, show good agreement with the DSC curves obtained by theoretically calculated data.     

爆破烟尘行为的实时模拟

在对爆破烟尘源及其特征分析的基础上,对爆破烟尘行为进行了探讨,提出了粒子系统的概念,进而对爆破烟尘行为、爆破烟尘在大气中的扩散进行了深入研究.基于建立的气固两相流动方程,运用四阶Runge-Kutta差分迭代算法,对冲击及蘑菇云阶段的烟尘时实行为进行了模拟;对于扩散阶段,建立了复杂状态下的带修正的多点高斯扩散模式,运用Java 3D技术对爆破烟尘的扩散行为实现了时实模拟.最后,编制出了BSMS模拟软件.     

半固态流变行为模型及应用

半固态成形是21世纪最具潜力的先进制造技术之一.分析了国内外半固态变形行为研究进展,重点阐述了近似单相本构关系模型、两相本构关系模型、宏观-微观耦合本构关系模型的特点及应用,特别是笔者提出的宏观-微观耦合本构关系模型反映了工艺参数和微观组织参数对半固态流变应力的影响.同时,笔者将新型宏观-微观耦合本构关系模型应用于Al-4Cu-Mg合金半固态反挤压过程的有限元数值模拟,获得了工艺参数对应力应变、温度、晶粒尺寸、液相体分数和挤压载荷等的影响规律,数值模拟结果与半固态实验结果基本一致.     

摆锤式自动平衡装置的建模与仿真

利用拉格朗日方程推导出摆锤式自动平衡装置的数学模型,依据现有实验台确定模型中的相应参数,应用龙格-库塔法对数学模型进行计算机仿真,分析摆锤质量对摆锤式自动平衡装置减振性能的影响。     

Morphology of porous silicon structures formed by anodization of heavily and lightly doped silicon

By computer simulation the growing process of porous silicon under p⁻-Si and p⁺-Si anodization in HF solution is studied. The model of electrochemical etching of p⁺-Si includes the relief selective mechanism, which allows one to establish the relationship between anodization conditions (current density, HF concentration, temperature and doping level) and the topological characteristics of porous silicon (PS). The simulation of p⁻-Si dissolution is based on the model of diffusion limited aggregation (DLA), taking into account the thermal generation of holes and the quantum confinement effect. The various morphology of simulated PS structures exhibits a close resemblance to that of experimental ones formed in p⁺-Si and p⁻-Si wafers. For simulated p⁻-Si-based PS layers the porosity profiles and fractal dimension are calculated. It is shown that PS in p⁻-Si is multifractal with fractal dimension varying monotonously from 0.1 to 3 with size increase.     

受大气湍流影响的光学波前模拟

大气湍流对光学波前的影响可以用Ｚｅｒｎｉｋｅ模式分析，由于Ｚｅｒｎｉｋｅ模式并非统计独立，需要转而寻找一种称为Ｋａｒｈｕｎｅｎ－Ｌｏｅｖｅ（简称Ｋ－Ｌ）函数的系数，它们统计独立，而且可以展开为Ｚｅｒｎｉｋｅ多项式的形式。本文介绍的就是用Ｋ－Ｌ函数构造随机波前的原理和仿真构造尝试。     

Computer simulation of deformation and fracture of small crystals by molecular dynamics method

Body-centred cubic iron whiskers having [100] and [110] axes were pulled in a molecular dynamics simulation using a supercomputer. The upper yield stress close to the theoretical strength was found. Above the upper yield stress, phase transformation was observed; at the same time the stress was greatly reduced. A new possible mechanism of twinning is proposed. The whiskers were pulled until they had broken into two pieces. Copper small crystals with and without a notch were sheared. It was observed that the edge dislocations were created at the surface and moved through and escaped from the crystals. Copper small single crystals with a notch were pulled. A half-dislocation was created near the tip of the notch. Sharp yield stress was observed. In medium deformation dislocations on different slip planes were created. Due to the cutting of dislocations the tensile stress increased.