O16偶宇称态的结构(Ⅰ)

本文在L-S耦合近似下,并且限于讨论2ω激发的组态,用δ相互作用严格求解了0⁺,2⁺及4⁺态。同时提出一种近似解的办法。即根据粒子的相干效应,可以近似地将双粒子双空穴的结构选为两个粒子相干和两个空穴相干的态。近似解的结果与严格解符合很好。在解释实验上,能量符合得不够好,但在解释O-0跃迁和E2跃迁上却相当成功。     

手征夸克模型下udss四夸克态的研究

在手征SU(3)夸克模型和扩展的手征SU(3)夸克模型的框架下, 用变分的方法系统地研究了同位旋为0、1, 自旋宇称为0⁺、1⁺和2⁺的udss四夸克系统6个低组态的能量. 模型的参数取自以前的工作, 它能很好地描述核子-核子散射相移以及核子-超子散射截面. S道相互作用的参数由拟合K介子和K^*介子的质量定出, 并且考虑了具有相同量子数的态之间的态混合效应. 结果表明, 同位旋为0且自旋宇称为1⁺的udss能量低于相应的K^*K^*,的阈能, 且该组态中KK^*的成分相当小, 因此该组态的宽度可能较小, 可视为一个可能的四夸克态的候选者.     

AsO+同位素离子X2∑+和A2∏电子态的多参考组态相互作用方法研究

采用包含Davidson修正多参考组态相互作用(MRCI)方法结合价态范围内的最大相关一致基As/aug-cc-pV5Z和O/aug-cc-pV6Z, 计算了AsO⁺ (X²∑⁺)和AsO⁺(A²∏)的势能曲线. 利用AsO⁺离子的势能曲线在同位素质量修正的基础上, 拟合出了同位素离子⁷⁵As¹⁶O⁺和⁷⁵As¹⁸O⁺的两个电子态光谱常数. 对于X²∑⁺态的主要同位素离子⁷⁵As¹⁶O⁺, 其光谱常数R_e, ω_e, ω_ex_e, B_e和α_e分别为 0.15770 nm, 1091.07 cm^-1, 5.02017 cm^-1, 0.514826 cm^-1和0.003123 cm^-1; 对于A²∏态的主要同位素离子⁷⁵As¹⁶O⁺, 其T_e, R_e, ω_e, ω_ex_e, B_e和α_e分别为5.248 eV, 0.16982 nm, 776.848 cm^-1, 6.71941 cm^-1, 0.443385 cm^-1和0.003948 cm^-1. 这些数据与已有的实验结果均符合很好. 通过求解核运动的径向薛定谔方程, 找到了J=0时AsO⁺(X²∑⁺)和AsO⁺(A²∏)的前20个振动态. 对于每一振动态, 还分别计算了它的振动能级、转动惯量及离心畸变常数, 并进行了同位素质量修正, 得到各同位素离子的分子常数. 这些结果与已有的实验值非常一致. 本文对于同位素离子⁷⁵As¹⁶O⁺(X¹∑⁺), ⁷⁵As¹⁸O⁺(X¹∑⁺), ⁷⁵As¹⁶O⁺(A¹∏)和⁷⁵As¹⁶O⁺(A¹∏)的光谱常数和分子常数属首次报导.     

原子核内多个核子关联的一些子结构

对于轻原子核,我们把两个声子相干的结构做为四个粒子集团的子结构α⁺,用同样的办法可以给出四个空穴集团的子结构β⁺。在此基础上,我们以¹⁶O及¹⁸O为例,研究了粒子团与空穴团之间的结构。发现它们之间存在着很强的斥力,因而最低的态是粒子团与空穴团松散开的结构。这样就从微观结构上解释了这种态的变形,并且这种结构对E2跃迁是相干加强的。为了进一步研究中重核的粒子关联结构,我们把L-S耦合的相干结构推广到赝L-S耦合的相干结构,并在j-j耦合表象中给出了表达式。应用此结构对⁵⁶Ni附近的原子核,做了一点初步的分析。     

氮化钒的选态双色可见紫外共振增强光电离和脉冲场光电子研究 (cited: 4)

对气态氮化钒(VN)分子在光子总能量为56900～59020 cm^-13∏0, v'=0)的单转动态, 然后再被紫外激光电离．这样的双色激光模式可以测量电子态、振动态和转动态都被选择和解析的氮化钒阳离子VN⁺(X²△; v⁺=0, 1, 2)光谱． 通过对转动解析的PFI-PE光谱模拟分析, 确定J⁺=3/2为基态离子态的最低转动能级, 从而确认VN⁺的基态电子态为²△_3/2．通过对VN+(PFI-PE)光谱的分析得到如下物理量的精确数值：VN⁺(X²△_3/2)的绝热电离能为IE(VN)=56909.5±0.8 cm^-1(7.05588±0.00010 eV),振动常数ω_e⁺=1068.0±0.8 cm^-1,反常振动常数ω_e⁺χ_e⁺=5.8±0.8 cm^-1;VN⁺(X²△_3/2)的转动常数B_e⁺=0.6563±0.0005 cm^-1,α_e⁺=0.0069±0.0004 cm^-1,平衡键长为1.529 ?;VN⁺(X²△_5/2)的转动常数B_e⁺=0.6578±0.0028 cm^-1,α_e⁺=0.0085±0.0028 cm^-1,平衡键长为1.527 ?;X²△_5/2,3/2自旋轨道耦合常数A=153.3±0.8 cm^-1     

强子衰变过程J/ψ→V+X,X→V+V的角分布分析

本文讨论了J/ψ的强子衰变过程J/ψ→V₁+X,X→V₂+V₃,V₂,V₃→2P(或3P)(其中V_i代表矢量介子,P代表赝标介子).对于具有不同自旋-宇称J^P的中间态X,得到了相应的角分布的螺旋度形式.这些公式对于利用BEPC上得到的J/ψ事例,确定上述过程中间态X的自旋-宇称是有帮助的.     

环戊酮光电离解离的实验和理论研究

本文介绍了真空紫外光电离质谱结合理论计算研究环戊酮单分子的光电离解离过程. 在9.0∽15.5 eV能量范围内,测量了环戊酮离子及其碎片离子的光电离效率曲线. 通过光电离效率曲线,将环戊酮分子的电离能确定为9.23±0.03 eV,并确认碎片离子为：C₅H₇O⁺,C₄H₅O⁺,C₄H₈⁺,C₃H₃O⁺,C₄H₆⁺,C₂H₄O⁺,C₃H₆⁺,C₃H₅⁺,C₃H₄⁺,C₃H₃⁺,C₂H₅⁺, C₂H₄⁺. 利用量子化学计算方法,在ωB97X-D/6-31+G(d,p)理论水平基础上,提出了C₅H₈O⁺的解离机制. 通过对环戊酮解离路径的分析,发现开环和氢迁移过程为环戊酮离子解离的主要路径.     

S?(12)群表示的填充与强衰变

本文讨论了(3/2)^-,(1/2)^-,(7/2)⁺等共振态在S?(12)群表示中的填充及其强衰变,发现16016,35100两个表示中的(3/2)^-粒子不能衰变到(1/2)⁺和0^-.通过改变运动方程质量项的符号使表示的宇称改变,就能将((3/2)^-,8)和((1/2)^-,1)填在572表示中,从而使它们能衰变到(1/2)⁺和0^-。但是,((3/2)^-,1)和(7/2)⁺仍然不能通过S?(12)对称的有效顶点衰变,本文还详细分析了S?(12)在基本粒子分类和强衰变中的成功之处与局限性,并讨论了这种局限性产生的原因。     

π-核双电荷交换反应与核结构

用相干结构核模型和格劳伯多次散射理论,计算了¹⁶O和¹⁸O的π-核双电荷交换反应截面。结果表明,由于核子的成对结构,同位旋非相似态之间的双核子跃迁显著增大。理论计算的¹⁸O（π⁺,π^-）¹⁸Ne与¹⁶O（π⁺,π^-）¹⁶Ne反应截面的比值,在¹⁶O基态不需含有太大的两个粒子-两个空穴组态成份时,便能很好符合实验。多步过程中间激发态的贡献也被估计了,表明贡献是小的。     

高能正负电子对的湮没与超窄共振ψ粒子的作用

本文给出了R=(σ(e⁺e^-→强子))/(σ(e⁺e^-→μ⁺μ^-))随能量上涨的一个解释。研究了新发现ψ粒子所具有作用的性质,指出其强度f²/(4π)～10^-5—10^-6。求得峰值截面σ₀=(12π)/m_ψ²(Γ(ψ→e⁺e     

LiC分子基态及其低电子激发态的多参考组态相互作用方法研究

采用包含Davidson修正的多参考组态相互作用(MRCI+Q)方法结合6-311++G(3df,3pd)基组计算了LiC分子基态(X4Σ-)以及五个低电子激发态(a2Π,b2Δ,c2Σ-,d2Σ+,A4Π)的势能曲线.将得到的势能曲线拟合到Murrell-Sorbie解析势能函数形式,确定了对应态的平衡结构Re、谐振频率ωe和离解能De等光谱数据,计算值与仅有的几个其他结果进行了比较.通过求解核运动的薛定谔方程首次报道了LiC分子几个低电子态在J=0下的振动能级、转动惯量和六个离心畸变常数(Dν,Hν,Lν,Mν,Nν和Oν).     

Intensities of the laser-induced fluorescence of 130Te2 and electronic transition strengths for the AOu+-XOg+ and BOu+-XOg+ systems

The intensities of the laser-induced fluorescence spectra of ¹³⁰Te₂, excited by Ar⁺ and He-Cd⁺ lasers, are measured for the AO_u⁺-XO_g⁺ and BO_u⁺-XO_g⁺ systems. The RKR potentials of the A, B and X states are calculated. These potentials are used for calculating Franck-Condon factors and r-centroids with due respect to rotation. The relative r-centroid dependences of the electronic transition strength were obtained first and then normalized in lifetimes.     

增加光子对和减少光子对相干态的统计性质

引入增加光子对相干态|ζ,q;m >_a=a^+m|ζ,q >和减少光子对相干态|ζ,q;-m >_b=b^m|ζ,q >,研究了这些态所描写的光场的统计性质。结果显示当在对相干态的a模增加光子时,两模的平均光子数均增加,亚泊松分布性质增强;当在对相干态的b模取走光子时,b模的平均光子数减少,而a模的平均光子数却增加;b模的亚泊松分布性质减弱,而a模的亚泊松分布性质却增强。我们还计算了场模间的相关度和场模的压缩。     

The H2S Spectrum around 0.7 μm

The overtone spectrum of H₂S has been recorded by intracavity laser spectroscopy in the 14100–14400 cm⁻¹spectral region. The rovibrational analysis was performed allowing one to assign not only lines involving the pair of interacting states {(402), (303)} ({(60⁺, 0), (60⁻, 0)} in local mode notation), but also lines involving the interacting states {(322), (223)} ({50⁺, 2), (50⁻, 2)} in local mode notation). Indeed, apart from the strong H₂₂interactions that link the rotational levels of the states (60^±, 0) on the one hand, and the rotational levels of the states (50⁺, 2) on the other hand, we observe that the rotational levels of the two pairs of states interact strongly through anharmonic and Coriolis-type resonances. These resonances transfer intensity to lines involving the (50⁺, 2) pair of states. Altogether 80 rotational upper-state levels have been observed and reproduced satisfactorily using an Hamiltonian matrix that takes explicitly into account the various interactions and assumes the same vibrational energy and rotational constants for the two components of the local mode pairs. The following band centers have been obtained: ν₀(60⁺, 0) = 14291.122 cm⁻¹and ν₀(50^±, 2) = 14284.705 cm⁻¹. Finally a local mode-type behavior is evidenced by the values of the Hamiltonian constants, and refined vibrational local mode parameters are obtained.     

Accurate spectroscopic properties of 10 Λ-S states and 25 Ω states of BS<Superscript>+</Superscript> cation including the electronic transition properties

The potential energy curves of 10 Λ–S states of BS⁺ yielded from the first four dissociation limits are calculated by the internally contracted multireference configuration interaction approach with the Davidson correction. The core-valence correlation and scalar relativistic corrections are included. Basis on the calculated potential energy curves, the spectroscopic parameters are evaluated. All the PECs are extrapolated to the complete basis set limit. The spin-orbit coupling are taken into account by the state interaction method with the Breit-Pauli Hamiltonian. Finally, the transition dipole moments, Franck-Condon Factors and radiative lifetimes of transitions from the 2³Π_0-, 2³Π₀₊, 2³Σ₀ ^- and 2³Σ₁ ^- states to ground state 1³Π₂ are predicted for future experiment.     

Resonance states in 12C and α-particle condensation

The states with J^π = 0⁺, 2⁺, and 4⁺ of ¹²C with excitation energies less than about 15 MeV are investigated with the alpha condensate wave function with spatial deformation and by using the method of ACCC (analytic continuation in the coupling constant) which is necessary for a proper treatment of resonance states. The calculated energy and width of the recently observed 2₂⁺ state are found to be well reproduced. The obtained 2₂⁺ wave function has a large overlap with a single condensate wave function of 3α gas-like structure. The density distribution is shown to be almost the same as that of the 0₂⁺ state that is regarded as a 3α Bose-condensed state, if the energy of the 2₂⁺ state is scaled down to the same value as the one of the 0₂⁺ state. Furthermore, the kinetic energy, nuclear interaction energy, and Coulomb interaction energy of the calculated 2₂⁺ state are shown to be very similar to those of the 0₂⁺ state. We conclude that the 2₂⁺ state has a structure similar to the 0₂⁺ state of Bose-condensate character with a dilute 3α gas-like structure. In addition, the resonance states, 0₃⁺, 0₄⁺, 4₂⁺, are also discussed.     

A new force field for the adsorption of H2, O2, N2, CO,H2O,and H2S gases on alkali doped carbon nanotubes

The main goal of this work is the generation of a new force field data set to the interaction of several gases such as H₂, O₂, N₂, CO, H₂O, and H₂S with alkali cation-doped carbon nanotubes (CNTs) using ab initio calculations at the MP2(full)/6-311++G(d,p) level of theory. Different alkali cations including Li⁺, Na⁺_, K⁺ and Cs⁺ were used to dope in the CNT. The calculated potential energy curve for the interaction of each gas molecule with each alkali cation-doped CNTs was fitted to an analytical potential function to obtain the parameters of the potential function. A modified Morse potential function was selected for the fitting in which the electrostatic interactions has been accounted by adding the β/r term to the Morse potential. The accuracy of the calculated force field was checked via Grand Canonical Monte Carlo (GCMC) simulation of the H₂ adsorption on Li-doped graphite and Li-doped CNT. The results of these simulations were compared with the experimental measurements and the closeness of the simulation results with the experimental data indicated the accuracy of the proposed force field. The main merit of this work is the derivation of a specific force field for interaction of each of six gases with four alkali cation-doped CNT, which can be used in molecular simulation of these 24 of systems. The simulation results showed the increase of the H₂ adsorption capacity of nanotube and graphite up to 50% and 10%, respectively, due to the insertion of Li ions.     

对力对于锕系核性质的影响

本文用处理对力的粒子数守恒方法来分析对力对于锕系核性质的影响,其中包括奇A核和偶偶核的内部激发谱、β衰变、α衰变等。文中首先根据实验测得的寄A核的内部激发谱,计及对力的影响,定出了单粒子能级的Nilsson参数(见表3和5)。然后利用此单粒子能级进一步分析了偶偶核的内部激发谱和β衰变。由于现有数据的限制,只分析了Th²²⁸,Th²³⁰,U²³²,U²³⁴和Cm²⁴⁴等核。由能级位置和β衰变的分析,     

闭壳层金掺杂钛氧团簇阴离子解离氢分子研究

Dissociation of molecular hydrogen (H₂) is extensively studied to understand the mechanism of hydrogenation reactions. In this study, H₂ dissociation by Au₁-doped closed-shell titanium oxide cluster anions AuTi₃O₇^- and AuTi₃O₈^- has been identified by mass spectrometry and quantum chemistry calculations. The clusters were generated by laser ablation and massselected to react with H₂ in an ion trap reactor. In the reaction of AuTi₃O₈^- with H₂, the ion pair Au⁺-O₂^2- rather than Au⁺-O^2- is the active site to promote H₂ dissociation. This finding is in contrast with the previous result that the lattice oxygen is usually the reactive oxygen species in H₂ dissociation. The higher reactivity of the peroxide species is further supported by frontier molecular orbital analysis. This study provides new insights into gold catalysis involving H₂ activation and dissociation.     

Single α-particle orbits and Bose-Einstein condensation in <Superscript>12</Superscript>C

Bosonic properties of α particles such as single-α orbits and occupation numbers in J^π = 0⁺, 2⁺, 1^- and 3^- states of ¹²C around the 3α threshold are investigated with the semi-microscopic 3α cluster model. As in other studies, we found that the 0⁺₂ (2⁺₂) state has dilute-3α-condensate-like structure in which the α particle is occupied in the single S (D) orbit with about 70% (80%) probability. The radial behaviors of the single-α orbits as well as the occupation numbers are discussed in detail in comparison with those for the 0⁺₁ and 2⁺₁ states together with the 1^-₁ and 3^-₁ states.