HS和HOO抽氢反应机理的研究

在B3LYP/6-311+G(3df,2p)水平上对HS和HOO反应中的所有物种进行了几何构型优化和频率计算,采用QCISD(T)/6-311+G(3df,2p)方法获得了各物种的单点能,构建了HS和HOO反应在单、三重态势能剖面.结果表明,HS与HOO反应体系中存在2种不同的抽氢通道,在单、三重态势能面上生成的产物分别为[1P1(H2O2+1S),1P2(H2S+1 O2)]和[3P1(H2O2+3S),3P2(H2S+3O2)].标题反应主要发生在三重态势能面上,优势通道[R→3 TS2→3P2(H2S+3O2)]的活化能为9.99kJ·mol-1.此结果对认识大气硫迁移转变规律具有实际意义.     

Some theoretical and practical aspects in the separation of humic substances by combined liquid chromatography methods

Permanent need to understand nature, structure and properties of humic substances influences also separation methods that are in a wide scope used for fractionation, characterization and analysis of humic substances (HS). At the first glance techniques based on size-exclusion phenomena are the most useful and utilized for relating elution data to the molecular mass distribution of HS, however, with some limitations and exceptions, respectively, in the structural investigation of HS. The second most abundant separation mechanism is reversed-phase based on weak hydrophobic interactions beneficially combined with the step gradients inducing distinct features in rather featureless analytical signal of HS. Relatively great effort is invested to the developments of immobilized-metal affinity chromatography mimicking chelate-forming properties of HS as ligands in the environment. Surprisingly, relatively less attention is given to the ion-ion interactions based ion-exchange chromatography of HS. Chromatographic separation methods play also an important role in the examination of interactions of HS with pesticides. They allow us to determine binding constants and the other data necessary to predict the mobility of chemical pollutants in the environment. HS is frequently adversely acting in analytical procedures as interfering substance, so more detailed information is desired on manifestation of its numerous properties in analytical procedures. The article topic is covered by the review emphasizing advances in the field done in the period of last 10 years from 2000 till 2010.     

HS和HONO反应机理的研究

采用密度泛函和耦合簇理论方法研究了HS与HONO的反应机理.在B3LYP/6-311+G(2df,2p)水平上对HS+HONO反应中的所有物种进行了几何构型优化和频率分析,通过内禀反应坐标(IRC)确认了反应物、过渡态、中间体和产物之间的相关性;采用CCSD(T)/6-311+G(2df,2p)方法获得了各物种的单点能.计算结果表明:HS+HONO的主要反应通道为HS+cis-HONO→p2-cis-IM1→p2-cis-TS→p2-IM2→P2(H_2S+NO_2),其反应活化能为71.26kJ·mol~(-1).     

模糊逻辑系统中的演绎定理和HS规则

Cancelled the first axiom L1) or the third axiom L3) of the classical formal logic system we established two kinds of quasi-formal deductive system, LG-Rand LG, respectively. In LG-R we proved that neither the deduction theorem nor the hypothetical syllogism (HS) rule held but a deduction theorem and an HS rule are obtained in a weak sense. We also proved that both the deduction theorem and the hypothetical syllogism(HS) rule hold in LG.     

非线性波方程新的显式精确解

利用Darboux和一个可化为标准Bernoulli方程的4阶常微分方程,统一地处理了三个著名方程KdV方程,Kadomtsev-Petviashvili(KP)方程和Hirota-Satsuma(HS)方程的求解问题.给出了这些方程一批新的具有更为丰富形式的精确解,其中包括孤波解和行波解.