Triangle Distribution and Equation of State for Classical Rigid Disks

The triangle distribution function f ⁽³⁾ for three mutual near neighbors in the plane describes basic aspects of short-range order and statistical thermodynamics in two-dimensional many-particle systems. This paper examines prospects for constructing a self-consistent calculation for the rigid-disk-system f ⁽³⁾. We present several identities obeyed by f ⁽³⁾. A rudimentary closure suggested by scaled-particle theory is introduced. In conjunction with three of the basic identities, this closure leads to an unique f ⁽³⁾ over the entire density range. The pressure equation of state exhibits qualitatively correct behaviors in both the low-density and the close-packed limits, but no intervening phase transition appears. We discuss extensions to improved disk closures, and to the three-dimensional rigid-sphere system.     

贵金属金的状态方程

 提出了一个热压强的计算公式,从而获得金的状态方程。并结合实验数据与文献中常用的其它两个状态方程进行了比较。结果发现,修正后的状态方程与实验数据吻合很好,略优于其它两个状态方程。     

铝锂合金材料状态方程的研究

 多数材料是应变率正敏感的,其屈服应力随着应变率的增加而提高;但是在应变率相关的动力学实验中,发现铝锂合金是应变率负敏感的,具有明显的冲击韧性特征。为了全面认识该种材料的动态力学行为,有必要进一步研究其在较高压力下的冲击压缩性能。通过轻气炮实验,测量了靶板自由面质点速度时程曲线等相关参量,得到了材料的D-u型Hugoniot线。实验揭示了在突加载荷作用之下,在应变率负敏感的铝锂合金材料中可出现类似于弹塑性材料中的双波结构,从而证明了所提出的“极限应变率负敏感粘塑性材料”这一概念的合理性。最后,在弱激波假设的前提下,推导了材料Hugoniot方程与Murnagham状态方程之间的关系,并以实验数据为基础得到了材料的状态方程参数。     

基于GPU求解椭圆型偏微分方程的并行算法

针对求解椭圆型偏微分方程的雅克比迭代算法和DRM算法进行基于GPU的CUDA加速算法研究.通过两个算例在GTX570显卡上对GPU加速算法进行验证.结果表明,在保证运算精度的前提下,雅克比迭代的GPU加速效率最高,在DOUBLE类型下的加速比可达到14倍左右,效率可达到53%左右;DRM算法在DOUBLE类型下的加速比最高可达到3.8倍,效率达到15%左右.     

原子核状态方程

介绍了在核子自由度占优势时原子核状态方程的一些知识,并对在饱和状态下直接研究和在重离子碰撞中间接研究原子核状态方程的情况做了评述． The knowledge of nuclear equation of state for which nucleonic effects are dominant is presented. The direct studies which close to the saturation state and the indirect studies involving heavy ion collisions on nuclear equation of state are reviewed.     

PETN炸药爆轰产物状态方程的理论研究

 采用van der Waals等效单组分流体模型和Ross硬球微扰理论软球修正模型,计算爆轰气相产物的状态方程;用石墨相、金刚石相、类石墨液相和类金刚石液相4种相态描述凝聚成分,由Gibbs自由能最小原理确定不同状态下的凝聚产物相态。对爆轰产物混合系统采用自由能最小原理,通过化学平衡方程组求解炸药爆轰产物系统的平衡组分。使用该理论计算PETN炸药Chapman-Jouguet（CJ）点的爆轰参数,其值与实验值符合得很好;同时计算了以CJ点为起始点的等熵卸载线,并与传统的Jones-Wilkins-Lee（JWL）状态方程的计算结果进行比较,发现计算的γ值是单调递减的,而JWL状态方程计算的γ值却出现了“双峰”现象。分析认为,传统的JWL状态方程给出的“双峰”变化,是由其函数形式自身决定的,并不对应实际物理过程。     

HMX炸药爆轰产物物态方程研究

采用自主研制的考虑产物组分间化学反应的类CHEQ程序研究HMX炸药爆轰产物物态方程,给出初始密度为1.90 g·cm^-3的HMX炸药CJ点的爆速和爆压,计算值与实验值符合较好;计算CJ点的爆轰产物组成,并与BKW和LJD的计算结果进行比较分析;同时给出过CJ点的等熵膨胀线上压强、 γ和产物组分随比体积的变化规律,加深对爆轰产物作功能力的认识.     

并联型光电设备稳定平台稳定解算研究

并联型光电设备稳定平台是针对光电跟踪系统需要而设计的一种新型并联机构,具有两个相互独立的转动自由度。以并联稳定平台为研究对象,介绍了动载体下并联稳定平台的工作原理,进行了并联稳定平台的运动学分析。采用齐次坐标变换方法,推导了从大地坐标系到平台定坐标系的转移矩阵,建立了并联稳定平台的稳定解算模型,进行了并联稳定平台的数值仿真研究。结果表明：随着旋转角增大,并联稳定平台的姿态角偏差和方位角偏差越来越大;在实际控制系统中若不考虑旋转角作用,这将严重影响并联型光电设备稳定平台的稳定精度。该研究为并联型稳定平台控制系统设计提供了一定的理论依据。     

Perturbative Treatment for Stationary State of Local Master Equation

The local approach to construct master equation for a composite open system with a weak internal coupling is simple and seems reasonable. However, it is thermodynamic consistent only when the subsystems are resonantly coupled. Efforts are being made to understand the inconsistency and test the validity of the local master equation. We present a perturbative method to solve the steady-state solutions of linear local master equations, which are demonstrated by two simple models. The solving process shows the stationary state as the result of competition between incoherent operations and the unitary creating quantum coherence, and consequently relate quantum coherence with thermodynamic consistency.     

Accurate First-Principle Equation of State for the One-Component Plasma

Accurate “first-principle” expressions for the excess free energy F_ex and internal energy of U_ex of the classical one-component plasma (OCP) are obtained. We use the Hubbard-Schofield transformation that maps the OCP Hamiltonian onto the Ising-like Hamiltonian, with coefficients expressed in terms of equilibrium correlation functions of a reference system. We use the ideal gas as a reference system for which all the correlation functions are known. Explicit calculations are performed with the high-order terms in the Ising-like Hamiltonian omitted. For small values of the plasma parameter Γ the Debye-Huckel result for F_ex and U_ex is recovered. For Γ ? 1, these depend linearly on Γ in accordance with the Monte Carlo findings for the OCP. The MC data for the internal energy are reproduced fairly well by the expression for U_ex obtained.     

Perturbative Treatment for Stationary State of Local Master Equation

The local approach to construct master equation for a composite open system with a weak internal coupling is simple and seems reasonable. However, it is thermodynamic consistent only when the subsystems are resonantly coupled. Efforts are being made to understand the inconsistency and test the validity of the local master equation. We present a perturbative method to solve the steady-state solutions of linear local master equations, which are demonstrated by two simple models. The solving process shows the stationary state as the result of competition between incoherent operations and the unitary creating quantum coherence, and consequently relate quantum coherence with thermodynamic consistency.     

一种适用于各向异性材料的修正PUFF物态方程

给出一种适用于各向异性材料的修正PUFF物态方程,既能体现各向异性材料在压缩和膨胀过程中材料体积变化的非线性特征,又能反映材料的各向异性强度效应.以正交各向异性材料二维碰撞问题和X射线辐照下的二维热击波为例,利用有限元方法编写程序进行数值模拟,对根据传统PUFF物态方程和修正PUFF物态方程计算得到的平均正应力值作对比研究,结果表明,低压和拉伸状态下二者存在明显差异,在高压下二者趋于一致.     

Ultrahigh-Pressure Equation of State for Copper at 0K

Based on the first-principles all-electron full-potential augmented-plane-wave plus local orbital method, an equation of state （EOS） at OK for copper up to 10000 GPa （10^8 bar） is presented. Our recommended EOS is in good agreement with the available experimental data. Furthermore, the agreement between theoretical EOS of hcp and fcc lattices at extremely compressed condition sets the foundation of spherical atom models for high density and high temperate plasmas.     

热传导方程三层并行差分格式初始条件的计算

给出二维热传导问题的三层差分格式初始条件的一种显式计算方法,对于由此形成的内边界预估校正三层并行差分算法,证明稳定性和收敛性定理.并行数值试验表明,方法稳定,且与通常采用隐式格式计算初始条件的方法相比,易于程序实现;与已有的扰动算法相比,能大幅度减小误差.     

铝的等温状态方程

 采用原位高压同步辐射X射线衍射技术,利用金刚石对顶砧（DAC）装置产生高压,选用高纯NaCl粉末作为传压介质与标压物质,在室温下、21.5 GPa的压力范围内,测定了铝的等温状态方程。利用Murnaghan方程对实验结果进行了数值拟合,得到铝的零压体弹模量及其一级压力导数分别为B₀=(77±2) GPa,B₀′=4.8±0.3。该结果同相关文献资料报导的值在误差范围内符合得很好,略显得较大,这是由于传压介质NaCl的非静水压效应所致。在实验所达到的压力范围内,未发现明显的相变迹象。     

一种同位旋相关的核物质状态方程

在Hartree–Fock近似下,从扩展的Skyrme有效相互作用出发,给出了一种同位旋相关的核物质状态方程.分析了在不同相对中子过剩时的核物质状态方程.发现在核物质的饱和点处,许多物理量的同位旋相关性能够近似地与相对中子过剩满足抛物线规律.     

核物质热力学系统的状态方程

用Bonn势和考虑强子质量Brown Rho(BR)标度规则修正,提出了改进的相对论平均场有效模型,由核物质的基态性质确定模型参数后,将该模型用来研究热密核物质系统的状态方程.     

爆轰产物物态方程（Ⅰ）——爆热、爆轰产物的等熵方程和物态方程

 讨论了爆热、爆轰产物的等熵方程和物态方程，试澄清这方面的一些疑点。     

不规则区域上并行求解Poisson方程

提出一种并行求解不规则区域上的Poisson方程方法,将不规则区域转化为带约束的三维结构网格表示,在该区域采用红黑排序并行求解Poisson方程.数值实验表明,方法可较好地解决不规则区域上的Poisson并行求解问题.同时评估了不规则区域对并行性能带来的影响.