I+HI(υ=0)→IH(υ′=0)+I体系散射共振态的理论研究

在QCISD(T)//MP2水平下,分别采用6-311++G**基组和SDD基组对重-轻-重反应I+HI(υ=0)→IH(υ′     

I+HI(v=0)→IH(v′=0)+I体系散射共振态的理论研究

在 QCISD ( T) / / MP2水平下 ,分别采用 6-3 1 1 ++G* * 基组和 SDD基组对重 -轻 -重反应 I+HI(ν=0 )→ IH(ν′=0 ) +I中的 H和 I的偏分势能面进行了 ab initio计算 ,指认出在 0～ 0 .5 8e V碰撞能范围内所产生的 6个散射共振态为 Feshbach共振 ,并与文献报道的量子散射理论计算与高分辨阈值光分离光谱实验结果进行了比较 .     

I＋HI（y=0）→IH（y′=0）＋I体系散射共振态的理论研究

在QCISD(T)//MP2水平下，分别采用6-311 G基组和SDD基组对重-轻-重反应I HI(p=0)→IH(√=0) I中的H和I的偏分势能面进行了abinitio计算.指认出在0～0.58eV碰撞能范围内所产生的6个散射共振态为Feshbach共振，并与文献报道的量子散射理论计算与高分辨阈值光分离光谱实验结果进行了比较.     

化学反应中散射共振态的理论研究进展

简述了化学反应中散射共振态的发现及研究意义, 介绍了散射共振态的理论方法, 对散射共振态进行了分类并给出不同类型散射共振态的形成机理, 分析了研究现状并对发展趋势作了展望。     

Na+I2→Na++I-2 反应中散射共振态的理论研究

化学反应中散射共振态是在特定的碰撞能下生成的中间态, 具有如定域性、光谱等束缚态的性质. 它与势能面强相互作用区的性质有密切关系, 但又与化学反应的过渡态不同. 由于散射共振态对化学反应的分支比、产物的能量分配和产物的角分布等有重要影响, 因此, 一直是理论和实验化学家的前沿研究课题[1]. 理论上, 对散射共振态生成机理的研究多集中在单势能面(电子基态)反应, 如H+H2, F+H2, I+HI(以及H的同位素D)等[2], 而对两态势能面反应散射共振态的研究则少见报道. Na+I2Na++I-2 离子对生成反应的微分截面已用激光-交叉分子束装置进行了实验研究[3]. 本文用量子反应散射和量子化学ab initio相结合的方法研究第一共振峰所对应的共振能、共振宽度、共振寿命、几何结构及电荷分布, 对共振类型作了指认, 分析了共振态的生成机理.     

Scattering Resonance States and Partial Potential Energy Surface of Reaction I ＋ HI （ v = 0 ） → IH （ v＇ = 0 ） ＋ I

The partial potential energy surface of the I ＋ HI →IH ＋ I reaction involving the translational and vibrational motions has been constructed at the QCISD（ T ）//MP4SDQ level with the pseudo potential method that is helpful to interpreting the scattering resonance states. The lifetimes of the scattering resonance states in the title reaction obtained from the partial potential energy surface are about 90-120 fs, which agrees with the result of high-resolved threshold photodetachment spectroscopy of anion IHI^- measured by Neumark.     

Scattering Resonance State of Br＋HBr（v=0）→BrH（v＇=0）＋Br Reaction Explored by Partial Potential Energy Surface Method

The partial potential energy surface（PPES） of Br＋HBr（v=0）→BrH（v＇=0）＋Br was designed by coupling the vibration energy and the minimum energy of the corresponding reaction path, Vmep. All the calculations were performed at the theoritical level of QCISD（T）/6-311＋＋G＊＊//MP2/6-31 1＋＋G＊＊. Based on the analysis of PPES, the dynamic ＂Eyring Lake＂ mechanism gave birth to the scattering resonance state. The resonance energy was also obtained via PPES. Then a lifetime matrix of the resonance state was established by solving the translational wave-function via the numerical propagation method. Then the reaction resonance lifetime was calculated to be 125 fs. It is in good agreement with the experimental result.     

Na+I_2——Na~++I_2~-反应中散射共振态的理论研究

化学反应中散射共振态是在特定的碰撞能下生成的中间态 ,具有如定域性、光谱等束缚态的性质 .它与势能面强相互作用区的性质有密切关系 ,但又与化学反应的过渡态不同 .由于散射共振态对化学反应的分支比、产物的能量分配和产物的角分布等有重要影响 ,因此 ,一直是理论和实验化学家的前沿研究课题 [1] .理论上 ,对散射共振态生成机理的研究多集中在单势能面 (电子基态 )反应 ,如H+ H2 ,F+ H2 ,I+ HI(以及 H的同位素 D)等 [2 ] ,而对两态势能面反应散射共振态的研究则少见报道 .Na+ I2 Na++ I- 2 离子对生成反应的微分截面已用激光 -交…     

偏分势能面及其应用(I):概念、构造方法及几个简例

提出了偏分势能面的概念,偏分势能面可由完全势能面抽取出来,也可采用abinitio方法进行构造.作为范例,给出了F+H2→FH+H,H+H2→H2+H,I+HI→IH+I及Na+I2→Na++I-等体系中几种偏分势能面的构造和应用.2可以看到,应用偏分势能面对于分析反应机理及散射共振态的生成方面显示突出优点.     

离子对生成反应Li+I2→Li++I2-的理论研究:从头算势能面和反应几率

采用QCISD(T)方法进行了构型优化及势能面扫描.电荷布居分析采用QCISD,对Li+I₂→Li++I₂^-离子对生成反应进行了系统的从头算理论研究:(1)构筑了两电子态(离子性²B₂态和中性分子2A1态)的完全从头算势能面,找到了两电子态势能面上的最低能量反应途径及两势能曲面的交线,据此确定了离子态与中性分子态之间的最可几交叉半径(R_c^max),计算了该处电子精细结构,得到的电子亲合能和解离能与实验光谱数据相吻合;(2)用Landau-Zener公式计算了离子对生成几率,发现了散射共振态的存在,这一结果与Na+I2→Na⁺+I₂^-体系非常相似,并比较了可得到的实验数据.     

粗糙玻璃表面上C~6~0膜的波导拉曼散射效应

本文首次报道粗糙玻璃表面上C~6~0薄膜的波导拉曼散射(WRS), 相对于未粗化玻璃表面情形,有较大的增强效应,用薄膜中波导膜的同步激发解释了这一效应.     

X-射线荧光分析散射幂函数法原理及其应用I·RhKα相干散射平方法

本文发现6~40号元素对能量为20keV的X_射线的质量吸收系数和质量相干散射系数之间呈二次幂函数关系,并据此提出了X_射线荧光定量分析校正基体效应的新方法——RhKa相干散射平方法.用国家标准物质GBW对该原理进行了验证.本法用于硅酸盐地质样品中微量元素的测定取得令人满意的结果.     

Ag（I）-EGTA螯合体系共振散射法测定痕量银

在Walpole缓冲介质和十二烷基苯磺酸钠（SDBS）溶液中,Ag（I）与乙二醇-双-（2氨基乙基醚）四乙酸（EGTA）可形成较稳定的无色螯合物微粒,使得体系的共振散射信号增强。该螯合物微粒在313nm处产生1个较强共振散射峰。研究表明,在最佳实验条件下,Ag（I）浓度在5．4×10^-3～2．7μg／mL范围内与共振散射强度△I呈较好的线性关系,检出限为0．17ng／mL。该方法用于废胶片中痕量银的测定,结果较满意。     

HO＋HoH→HoH＋oH反应的散射共振态与同位素效应的研究

在大气化学如燃烧反应和对流层各种有机化合物的降解中,HO＋HoH→HoH＋oH这一反应的研究格外受到关注．我们用abinitio方法构建了该体系的偏分势能面,并用其过渡区域里的动态Eyring湖解释散射共振态的形成机理,同时给出了共振能数据,估算了第一共振寿命．另外,我们还研究了同位素反应H^18O＋HOH→H^18OH＋OH和DO＋HOH→DOH＋OH．鉴于上述两个反应能够影响到等温层水中同位素的成分,HO＋HOH→HOH＋OH反应模型的建立对于理解O原子同位素的抽提反应有着重要的意义．     

Acidity constants in different media (I=0 and I=0.1 M KCl) from the uncertainty perspective

Procedures for estimating the measurement uncertainty for the acidity constant Ka (or the pKa value) in different media (I=0 and I=0.1 mol L(-1) KCl), as determined by potentiometric titration, are presented. The uncertainty budgets (the relative contributions of the different input quantities to the uncertainty in the result) of the pKa (I=0) and pKa (I=0.1 mol L(-1) KCl) values are compared. Unlike the values themselves, the uncertainties and uncertainty budgets of the values are comparable. The uncertainty estimation procedures are based on mathematical models of pKa measurement and involve the identification and quantification of individual uncertainty sources according to the ISO GUM approach. The mathematical model involves 52 and 48 input parameters for pKa (I=0) and pKa (I=0.1 mol L(-1) KCl), respectively. The relative importance of each source of uncertainty is discussed. In both cases, the main contributors to the uncertainty budget are the uncertainty components due to the hydrogen ion concentration/activity measurement, which provide 63.7% (for pKa (I=0)) and 89.3% (for pKa (I=0.1 mol L(-1) KCl)) of the uncertainty. The remaining uncertainty contributions arise mostly from the limited purity of the acid. From this work, it is clear that the uncertainties of the pKa (I=0.1 mol L(-1) KCl) values tend to be lower than those of the pKa (I=0) values. The main reasons for this are that: (1) the uncertainty due to the residual liquid junction potential is nominally absent in the case of pKa (I=0.1 mol L(-1) KCl) due to the similarly high concentrations of background electrolyte in the calibration solutions and measured solution; (2) the electrode system is more stable in solutions containing the 0.1 mol L(-1) KCl background electrolyte and so the readings obtained in these solutions are more stable.     

聚乙烯广角激光散射研究(Ⅱ)

本文用广角激光散射仪考察了带有同心圆消光环的聚乙烯球晶的Hv光散射图形,用有效偶极矩模型解释了图形的成因,从而探讨了晶片的扭曲现象,理论分析与实验结果相一致。     

Scattering Resonance States and Partial Potential Energy Surface of Reaction I+HI(v=0)→IH(v′=0)+I

The partial potential energy surface of the I HI→IH I reaction involving the translational and vibrational motions has been constructed at the QCISD(T)//MP4SDQ level with the pseudo potential method that is helpful to interpreting the scattering resonance states. The lifetimes of the scattering resonance states in the title reaction obtained from the partial potential energy surface are about 90-120 fs, which agrees with the result of high-resolved threshold photodetachment spectroscopy of anion IHI- measured by Neumark.     

Ag(Ⅰ)-EGTA螯合体系共振散射法测定痕量银

在Walpole缓冲介质和十二烷基苯磺酸钠(SDBS)溶液中,Ag(Ⅰ)与乙二醇-双-(2-氨基乙基醚)四乙酸(EGTA)可形成较稳定的无色螯合物微粒,使得体系的共振散射信号增强.该螯合物微粒在313 nm处产生1个较强共振散射峰.研究表明,在最佳实验条件下,Ag(Ⅰ)浓度在5.4×10-3～2.7 μg/mL范围内与共振散射强度△I呈较好的线性关系,检出限为0.17 ng/mL.该方法用于废胶片中痕量银的测定,结果较满意.     

四磺基铁(Ⅲ)酞菁二级散射和反二级散射法测定人血清白蛋白

在pH2．0的Clark-Lubs缓冲液中,人血清白蛋白与四磺基铁(Ⅲ)酞菁结合而使二级散射和反二级散射急剧增强。在0～2．3mg／L和0～3．4mg／L浓度范围内,二级散射和反二级散射的增强与人血清白蛋白浓度呈线性关系,检出限分别为0．40mg／L和0．16mg／L。还考察了某些共存物质的影响,讨论了反应机理。     

Scattering Resonance States and Partial Potential Energy Surface of Reaction I+HI(v=0)→IH(v′=0) +I

Introduction Scattering resonance states in chemical reactionsattract much interest of both theorists and experimental-ists because the rate of a chemical reaction, state distri-bution and space distribution of the products are con-trolled by those states[1]. Scattering resonance states,also called quasi-bound states, are formed in theprocesses of energy transitions, such as collision andray radiation processes. Those states are very closelyrelated to the structure and spectroscopy of the tran…