Statistical theory for hydrogen bonding fluid system of AaDd type (Ⅲ): Equation of state and fluctuations

The equation of the state of the hydrogen bonding fluid system of AaDd type is studied by the principle of statistical mechanics. The influences of hydrogen bonds on the equation of state of the system are obtained based on the change in volume due to hydrogen bonds. Moreover, the number density fluctuations of both molecules and hydrogen bonds as well as their spatial correlation property are investigated. Furthermore, an equation describing relation between the number density correlation function of "molecules-hydrogen bonds" and that of molecules and hydrogen bonds is derived. As application,taking the van der Waals hydrogen bonding fluid as an example, we considered the effect of hydrogen bonds on its relevant statistical properties.     

Silylation of porous glass supported platinum catalysts

Effect of silylation with hexamethyldisilazane on adsorption and catalytic properties of porous glass-supported platinum catalysts has been studied. Catalytic activity decreases markedly with an increase in surface coverage by trimethylsilyl groups for all the following reactions examined: hydrogenation of benzene, dehydrogenation of cyclohexane and dehydrocyclization of n-hexane.

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Statistical theory for hydrogen bonding fluid system of A_aD_d type (I): The geometrical phase transition

The influence of hydrogen bonds on the physical and chemical properties of hydrogen bonding fluid system of AaDd type is investigated from two viewpoints by the principle of statistical mechanics. In detail, we proposed two new ways that can be used to obtain the equilibrium size distribution of the hydrogen bonding clusters, and derived the analytical expression of a relationship between the hydrogen bonding free energy and hydrogen bonding degree. For the nonlinear hydrogen bonding systems, it is shown that the sol-gel phase transition can take place under proper conditions, which is further proven to be a kind of geometrical phase transition rather than a thermodynamic one. Moreover, several problems associated with the geometrical phase transition and liquid-solid phase transition in nonlinear hydrogen bonding systems are discussed.     

光场横向效应导致CO2激光器混沌运转的实验研究

对横向效应导致单纵模多横模CO_2激光器失稳进行了实验研究.观测到了经各种途径到达的激光混沌态,并对其物理机制进行了探讨.     

Anomalous (S2 → S0) luminescence of some derivatives of triphenylmethane dyes and their complexes with rare earth metals

Anomalous S₂ → S₀ fluorescence and T₂ → S₀ phosphorescence have been found in several triphenylmethane derivatives. This phenomenon can be explained by a large energy gap between the S₂ and S₁ levels, approximately 14000 cm^?1. Some of the investigated compounds exhibit also a normal long-wave fluorescence in spite of the fact, that the S₂ ? S₁ energy gap does not change significantly. However, in these cases absorption spectra reveal a high oscillator strength of the S₁ → S₀ transition. The coordination of a lanthanide ion quenches in several cases the normal S₁ → S₀ fluorescence whereas the S₂ → S₀ one is not affected significantly.     

ICP-AES法测定蒙药紫癜灵中多种微量元素

蒙药含有多种氨基酸和丰富的微量元素,特别是人体必需的微量元素含量相对较高,而对人体有害的重金属元素含量相对较低。采用微波消解ICP-AES法同时测定了治疗过敏性紫癜的蒙药紫癜灵中Ca, Mg, Sr, Fe, Mn, Zn, Cu和Pb等15种微量元素。紫癜灵的临床药效实验,选择了过敏性紫癜患者260例,其中男性140例,女性120例;年龄最小6岁,最大62岁,6～16岁年龄段最多,占病人总数的90%左右。治疗结果显示：治愈234例,占90%;显效13例,占5%;有效11例,占4.23%;无效2例,占0.77%;总有效率达99.23%。紫癜灵中含有丰富的微量元素,尤其锶的含量相当高。方法的加标回收率在94.63%～106.40% 之间,相对标准偏差RSD≤3.17%,检出限≤0.009 μg·L-1。     

Af型自由基均聚反应的固化理论(Ⅲ)──高分子凝胶网络缺陷

应用高分子反应统计理论,分析了高分子网络的形成过程,讨论了A_f型自由基均聚反应凝胶网络中的缺陷悬吊环的数目及其形成几率.     

一种基于感兴趣区域提取的医学图像检索技术

针对胸部CT扫描图像库，提出了一种基于感兴趣区域提取的图像检索方法．首先为了提取感兴趣区域，提出一种基于灰度层共现矩阵的区域增长算法，分割出病灶区域，再通过闽值算法进行边界的磨合，然后针对感兴趣区域提取形状和分布特性作为图像匹配准则的客观依据．最后，将该算法与其他底层特征算法进行比较和分析．实验结果表明，该算法能够比较有效地应用于基于内容的医学图像检索系统中．