sl玻色子体系在U(2l+1)O(2l+2)过渡区的严格解

利用无穷维李代数方法得到了相互作用sl玻色子体系在U( 2l+ 1 ) O( 2l+ 2 )过渡区的能谱和波函数的严格解 .给出了该系统Bethe假定方程的数值解法 .     

Bi_(1.9)Sb_(0.1)Sr_2Ca_2Cu_(2+x)O_y 的超导特性(x=0,0.4,0.8,1.0,1.2,1.6)

文中报道了 Bi_(1.9)Sb_(0.1)Sr_2Ca_2Cu_(2+x)O_y,系列的交流磁化率测量及 X 射线衍射结果,发现超导转变温度对于 Cu 的组份非常敏感,当 x=0.4时,样品在136.5K 出现抗磁性,其 X 射线衍射图中新相衍射峰较85K 超导相的峰更强,因此 Cu 的价态和配位数在形成高和 T_c 超导相中起着至关重要的作用.     

A theoretical study of the non-adiabatic charge transfer process Ar2+ (3 P) + He(1 S) → Ar+(2 P) + He+(2 S)

CI calculation with a large basis have been used to calculate the two lowest ³Π adiabatic potential energy curves for the title reaction. These potentials have been transformed to diabatic potentials by employing a recipe based on the CI coefficients. Quantum mechanical close coupling calculations in the diabatic basis have produced total and differential cross sections which are in good agreement with experimental data. Full quantum mechanical and Landau-Zener calculations of the total cross section are in fair agreement with recent experimental measures and by small changes to the diabatic potentials can be brought into essentially exact agreement.     

(2+1)维SU(2)真空波函数四级近似的解析计算

考虑到幺模条件造成波函数选取的任意性，把不连接图代换成复杂的连接图，重新计算μ₀和μ₂得到更令人满意的结果．     

(1/2+1/2+1)腔型热阴极微波电子枪

 介绍了一种新型的轴耦合热阴极微波电子枪的设计，该枪采用了缩短首腔以及在首腔与主加速腔间插入耦合半腔的设计思想，在不破坏粒子束性能的基础上尽量减小反轰功率，给出了用Superfish 及Pamela软件进行物理设计以及粒子动力学计算的结果，在脉冲宽度为6μs, 重复频率为25Hz时，阴极上平均反轰功率为3.6W,达到设计要求。     

(C_5H_(11)N_2)~+和(C_7H_(12)N_2)~(2+)的NMR研究

结合1H NMR,13C NMR谱,分别对钨、钼配合物{WO2(C10H6O2)2(C5H11N2)2[H2N(CH2)3NH2]}3(1),{(C5H11N2)2[H2N(CH2)3NH2][MoO2(C10H6O2)2]}(2),{(C7H12N2)2[MoO2(C10H8O2)2]}(3)晶体结构中小分子环进行了归属.其中,配合物1和2中(C5H11N2)+的NMR研究证实了六元环由1,3-丙二胺和乙腈化合而成,配合物3中(C7H12N2)2+的NMR谱图证实了七元环由乙二胺和乙酰丙酮化合而成,并且推导出这些亲核加成-消除反应的反应机理.配合物1~3中的小分子环的合成在其它体系中尚未见报导,而在合成它们的反应中作为新产物随主体晶体析出,并由晶体结构解析和NMR得到了证实.     

sl玻色子体系在U(2l+1)→O(2l+2)过渡区的严格解

利用无穷维李代数方法得到了相互作用sl玻色子体系在U(2l+1)→O(2l+2)过渡区的能谱和波函数的严格解. 给出了该系统Bethe假定方程的数值解法.     

(2+1)维SU(2)真空波函数五级近似的解析计算

采用截断本征方程的方法,利用么模条件,合理选取图形,由一至四阶图推出五阶图,计算出五级真空波函数的μ₀和μ₂与四级真空波的μ₀和μ₂有较大的差别,初步看到该方法的收敛性不能令人满意,并有待于进一步研究.     

Quasi-classical rate constants for the inelastic process O2(υi≫ 1) + O2 → O2(υf) + O2

Rate constants have been calculated using quasi-classical trajectories (QCT) for the vibrational relaxation of highly excited O₂:O₂(X³Σ?,v_i) + O₂(X³Σ?,0) → O₂(X³Σ?,v_f) + O₂(X³Σ?) with 22 ≤v_i≤28. The present full-dimensional QCT results agree very well with recent quantum reduced dimensionality calculations, giving further support to the hypothesis that the observed experimental jump in depletion rates would be due partially to enhanced vibrational relaxation.     

2+1维SU(2)规范模型的弦张力

本文对两种具有严格基态解的格点哈密顿量,采用变分法计算了2+1维SU(2)规范模型的弦张力.     

势垒高度对Cl+H2(D2)反应的影响

使用三维含时波包方法在两个势能面上研究了Cl+H2(D2)反应．所使用的两个势能面都是从CW(Capecchi和Wener)势能面得到的，第一个是CW势能面的基态面加自旋轨道耦合修正，第二个是CW势能面的基态面没有自旋轨道耦合修正．在这两个势能面上得到了碰撞能从0.1到1.4 eV的积分截面以及反应几率．对于Cl与D2反应，考虑自旋轨道耦合后由于势垒高度的增加反应截面向高能处有一个平移，但Cl与H2反应在低能处的反应活性反而增大了，原因是虽然自旋轨道耦合效应增加了势垒高度，同时减小了势垒宽度，隧道效应更加明显，而隧道效应在低能处起着比较重要的作用，所以反应活性比较大．当碰撞能大于0.7 eV时，没有考虑自旋轨道耦合时势垒高度较低，因而反应活性较大．     

Charm changing weak decays 1/2+ → 3/2+ + 0−/γ in SU(4) and SU(8) w

Weak decay modes (1/2⁺ → 3/2⁺ + 0⁻/γ) of charmed baryons are studied. Relations among the various decay amplitudes are derived in isospin, SU(3), SU(4) and SU(8) _w symmetries. Sextet dominance in SU(3) forbidsB(3) →D(10) +P(3*) decays. 20″ dominance in SU(4) specifies all the decays in terms of Θ⁻ decays. Weak decays of Θ* ₃ ⁺⁺ and Θ⁻ are also discussed. SU(8) _w symmetry predictsα , which is consistent with the experimental value.     

Observation of a strong correlation between g(2+ γvib) and g(2+ rot) in strongly deformed nuclei

The E2/M1 multipole mixing parameters of cascade transitions in γ-vibrational bands of ¹⁵⁴Gd, ¹⁶⁶Er and ¹⁶⁸Er have been determined by γ -@#@ γ directional correlation measurements as: \(\delta \left( {{}^{154}{\text{Gd}}\left( {3_\gamma ^ + \to 2_\gamma ^ + } \right)} \right) = - 4.3_{ - 2.1}^{ + 9.4}\) and \(\delta \left( {{}^{166}{\text{Er}}\left( {5_\gamma ^ + \to 4_\gamma ^ + } \right)} \right) = + 1.94_{ - 0.21}^{ + 0.23}\) (with conversion data [15] taken into account) These data were used to derive g(2⁺γvib) ? g(2⁺ rot). The results, together with g-factors derived from direct measurements by IPAC and Mossbuer spectroscopy [10] or by use of transient fields [9, 31] exhibit a strong correlation between both g-factors, i.e. if g(2⁺ rot) is large g(2⁺ γvib) is small and vice versa. The most direct and most simple interpretation is the assumption of a more or less different density distribution of protons and neutrons in the nuclei.     

The ion-molecule reaction O+ (4S) + N2(X1Σ+) → NO+ (X1Σ +, v′) + N(4S) and the predissociation of the A2Σ+ and B2Π states of N2O+

The potential energy surfaces (PESs) for several electronic states involved in the reaction O⁺ (⁴S) + N₂(X¹Σ⁺) → NO⁺ (X¹Σ ⁺, v′) + N(⁴S) and the role of the ionic N₂O⁺ intermediate have been investigated by ab initio calculations. The ⁴A″ PES, which correlates with the ground state educts, has a barrier of about 1 eV, and therefore at low collision energies the reaction cannot take place adiabatically on this surface. However, the spin-orbit coupling in the entrance channel allows the system to pass into the Renner-Teller system of the X² Π electronic ground state of the N₂O⁺ intermediate. The reaction then proceeds on these surfaces up to the region in the exit channel where a similar coupling allows it to reach the product quartet asymptote. At collision energies higher than about 1 eV, the reaction proceeds mainly on the adiabatic PES of the ⁴A″ state. The A²Σ⁺ state of N₂O⁺ predissociates via a vibronic coupling with the B²Π state, and in bent structures via a spin-orbit coupling with the ⁴A″ component of the ⁴II state. The electronic structure of the B²Π state is found to be of crucial importance for the understanding of the reactive processes in low lying electronic states of N₂O⁺.     

CS2+( 2Πg )的(1+1)光解离动力学研究

在气束条件下,利用483．2nm的激光（3＋1）共振增强多光子电离（REMPI）CS2分子以产生CS2＋离子源,用另一束可调谐激光在424－482nm内,通过对CS2^+(x^2∏g)(1+1)双光子共振解离产生的碎片离子发谱的探测,来获取CS2^+的光解离动力学信息,光解离碎片S^+的激光发谱（PHOFEX）可归属为CS2^+（A^2∏u,3/2(v′=0-4,v′＝v1_(1/2)v2-)←X^2′∏g,3/2(0,0,0))和（A^2∏u,1/2(v=0-4)←X^2∏g,1/2(0,0,0))跃迁,对CS2^+光解离动力学的研究表明,其产生S^+的通道为：（i)CS2吸收一个光子从基态X^2∏g共振激发至A^-2∏u态,（ii)已布居的A^-2∏u态的振动能级和X^2-∏g态的高振动能级产生耦合,（iii)吸收第二个光子从上述耦合的振动能级进一步激发至B^2∑u^+态,再通过B^-2∑u^+态与^4∑^-态间的自旋－轨道相互作用,经由4∑^-排斥态解离产生S^+_CS。     

Quantum chemical study of the (Z)-2-penten-1-ol (HOCH2–CH = CHCH2CH3) + OH + O2 reactions

ABSTRACT

The mechanism and products of the reaction of (Z)-2-penten-1-ol [(Z)-PO21] with OH radical in the presence of O₂ have been elucidated by using high-level quantum chemical methods CCSD(T)/6-311+G(d,p)//BH&;HLYP/6-311++G(d,p). The calculations clearly indicate that addition channels contribute maximum to the total reaction and H-abstraction channels can be neglected at temperatures of 220–500 K. The rate constant for the reaction of OH radical with (Z)-PO21 at 298 K is computed to be 1.22 × 10^?10 cm³ molecule^?1 s^?1, which is in stronger agreement with the previously reported experimental values. The kinetic data obtained over the temperature range 220?500 K are used to derive an non-Arrhenius expression: k = 3.69 × 10^?13 × exp(1763.7/T) cm³ molecule^?1 s^?1. For the reaction of (Z)-PO21with OH radical in the presence of O₂, the major primary reaction products found in this study are propanal [CH₃CH₂C(O)H] and glycolaldehyde [HOCH₂C(O)H], whereas formaldehyde [HC(O)H], 2-hydroxybutanal [CH₃CH₂CH(OH)C(O)H] and the epoxide P18 are anticipated to be minor products. The calculated results are consistent with the recent experimental observations.     

SU(6)对称性和(3/2)~+重子电磁质量差

(1/2)~+和(3/2)~+重子属于SU(6)群的56维表示。假定总磁矩按照正规表示变化,除SU(3)对称性给出的结果外,还可以预言     

Time-dependent quantum wave packet and quasiclassical trajectory studies of the Au(2S) + H2(X1∑+g) → AuH(X1∑+g) + H(2S) reaction

The time-dependent quantum wave packet (TDWP) and quasiclassical trajectory calculations (QCT) are carried out for the Au(²S) + H₂(X¹∑⁺_g) → AuH(X¹∑⁺_g) + H(²S) reaction on a global potential energy surface. The reaction probabilities at a series of J values, integral cross sections (ICSs) and differential cross sections of the title reaction are calculated by the TDWP method. For reaction probabilities, there are a mass of sharp oscillations at low collision energy, which can be attributed to resonances supported by the potential well. Due to the endothermicity of the title reaction, the total ICS shows a threshold about 1.53 eV. In order to further investigate the reactive mechanism, the lifetime of complex is calculated by QCT method. At the low collision energy, most intermediate complexes are long lived, which implies that the reaction is governed by indirect reactive mechanism. With the collision energy increasing, the direct reactive mechanism occupies the dominant position. Due to the change of the reactive mechanism, the angular distribution shifts toward the forward direction with collision energy increasing. The isotopic variant, Au + D₂→AuD + D reaction, is also calculated by TDWP method. The calculated reaction probabilities and ICSs show that the isotope effect reduces the reactivity.