模式识别在化学键研究中的应用——金属间化合物若干经验规律

在键参数空间φ(z₁,z₂,R₁/R₂,εφ,△φ)中,用模式识别方法处理了2005个金属间化合物晶型的信息,总结出若干经验规律,并讨论了这些规律的物理基础。     

YBaCuO缺氧和掺氟效应的从头算研究

应用含自洽晶体场MadeLung势全电子从头算方法计算了模拟缺氧和掺氟的YBaCuO原子簇.结果表明:缺氧效应导致CuO_2面上的电荷浓度增加,空穴数目减少,Cu的化学价降低以及Cu-O共价键严重削弱.掺入的氟占据顶角氧的位置,可使局域电子结构恢复到不缺氧YBA_2CU_3O_7时的状态.借助于计算得到的化学键特征,对前人推测氟取代链上氧空位的观点提出质疑.     

MeX－REX_3系相图的模式识别分析

用化学键参数－模式识别或人工神经网络方法研究ＭｅＸ－ＲＥＸ_３型熔盐相图，总结中间化合物的形成、化学配比和Ｍｅ_３ＲＥＸ_６型化合物同分或异分熔化规律，并对其熔点或分解点进行预报．     

PuⅠ偶宇称光谱能级的模式识别研究

本文利用偏最小二乘法（ＰＬＳ）－反向传播网络（ＢＰＮ）方程对ＰｕⅠ偶宇称光谱有级进行了指认,结果与实验相符。表明ＰＬＳ－ＢＰＮ可用于复杂子光谱能级归属的分类。     

句法模式识别研究芳烃致癌(一)——计算方法和经验规律

用句法模式识别研究多环芳烃分子图形与致癌活性的关系,总结出它包含致癌信息的特征曲线,并研究了分子伸展度和角品度对致癌活性的影响。     

金属卤化物熔盐系相图的规律及计算机预报

Rules of molten salt phase diagrams of binary system MeX-Me’X4 (Me is monovalent metal, Me’ quadrivalent metal, X halides) were investigated using chemical bond parameter and pattern recognition-artificial neural networks method. Formability of intermediate compounds, chemical stiochiometry, melting type (congruent or incongruent) of intermediate compounds Me2Me’X6 and MeMe’X5 were summarized and predicted, the results were of good reliability.     

分子动力学模拟研究LiCl急冷非晶形成过程中的局部结构

The local structure of quenching process of lithium chloride has been studied by molecular dynamics simulation. The sequentially-quenched model was adapted. When the equilibrium reached at the melting point 878 K, the system was fastly quenched to 698 K and then the system relaxed to equilibrium. The process was repeated as above and the system was quenched to 498 K, 298 K, and 198 K, respectively, We calculated the quadratic invariants Q_l histograms at different temperatures by averaging the Q_l values of theinstantaneous configurations with the method of fond spherical harmonics statistics under equal neighbor number. Consulting the Q_l histograms of the linear combination model with a parameter of square deviation in which model the local diamond structure was predominant, we found that the Q_l histograms from the model and those from the simulation were very similar. The results showed that in the quenched LiCl system the local orientation obviously tended to be binary diamond structure (like GaAs) and the square deviation in model would be decreased with the lowering of simulation temperature.     

铝酸钠熔体Monte Carlo法计算机模拟研究

用计算机Monte Carlo法研究铝酸钠熔体结构. 计算了径向分布函数和局部结构. 表明NaAlO_2熔体是由畸变的共隅AlO_4四面体离子集团、Na~+离子和xNa~+·yO~(2-)离子集团所组成.     

从头计算中Fm(z)积分系列计算的最优方案——向上和向下结合的递推法

本文阐明了量子化学从头计算中的Gauss积分函数Fm(z)用递推公式计算时误差传递和变化的定量规律.提出了向上和向下递推相结合进行Fm(z)系列计算的最优方案,它保证绝对误差在递推过程中只减不增,对递推基项无附加的精度要求,可用于改进各种Fm(z)程序.本法与Schaad公式相结合,用于P、d、f和g型Gauss函数的计算,可分别节约加法运算40％以上和乘法、指数运算60%以上.     

镀锡钢板淬水斑形成机理的研究

运用金相显微镜、扫描电镜微区分析研究了镀锡钢板表面缺陷--淬水斑的形貌;运用高速摄影技术考察了表面锡层受热熔化后与热的液态水接触时水的蒸发汽化的过程;运用模式识别算法处理工业生产条件与淬水斑形成与否的对应关系.结果表明淬水斑是由尺寸约0.01至0.1mm的具有波纹状凹凸不平的锡表面小区的群落所组成,因凹凸不平引起光散射,故与锡表面其他部分相比呈暗色.有些淬水斑伴随有氧化物组成的细小白点.表面有熔锡层的热钢板与热水相遇时锡表面有时可观察到汽膜快速生灭并使凝固的锡表面凹凸不平的过程.故推测水在熔锡表面不稳定的过渡沸腾模式应是淬水斑的成因.结合工业数据处理得到了淬水斑形成条件的数学模型.适当调整钢板速度和水温等以避免不稳定的过度传热模式可抑制淬水斑的形成.