Unified Treatment of Systematics for Even-Even Nuclei with A≥70

By the concept of effective boson numbers, systematics of E₂₁+E₄₁+E₆₁+, R=E₂₁+/E₄₁, B(E2, 0₁⁺→2₁⁺) and Q₀ for even-even nuclei with A≥70 are presented. New features of energy spectra are noticed and an intuitive understanding is given.     

Regional Systematics for Even-Even Medium-Heavy Nuclei

The fluctuation of the δV_np, and δV_NN is taken into account to evaluate the np interaction and pairing strength of nuclei more precisely than the simple N_πN_v[or N_nN_p/(N_n+N_p)]parametrization. Regionally elegant systematics are noticed for the excited energy of the ground β and γ bands. The systematics of the β and γ bands are presented in detail for the first time. Correlation phenomenon of the general behavior of different bands in the same region is pointed out.     

关于93Mo中21/2+晕阱的来源(英文)

本研究通过壳模型计算研究了N=51的同中子素91Zr、93Mo和95Ru中高自旋晕态21/2+的同核异能态现象。计算发现,低角动量的p_1/2轨道上的质子是仅在93Mo中存在21/2+晕阱的主要原因。同时,本工作还研究了N=52的同中子素92Zr、94Mo和96Ru中10₁+-12₁+能级结构的系统性,发现94Mo中的10₁+-12₁+能级间隙相对最小,考虑到与93Mo的17/2₁+-21/2₁+能级相似的组态,这一结果为93Mo中出现21/2+晕阱提供了补充性的论证。Isomerism of the high-spin yrast 21/2+ states of the N=51 isotones 91Zr, 93Mo and 95Ru has been investigated using the shell model calculations. It is found that the low-j πp_1/2 is responsible for the only yrast trap in 93Mo. In addition, the relatively smaller 10₁+-12₁+ level spacing in 94Mo has been found by investigating the systematics of the 10₁+-12₁+ level structures in the N=52 isotones 92Zr, 94Mo and 96Ru. This result provides a supplementary argument to the origin of the 21/2+ yrast trap in 93Mo from the viewpoint of the similarity between the configurations of 10₁+-12₁+ states in 94Mo and those of 17/2₁+-21/2₁+ states in 93Mo.     

一个新的自由能函数对介电高弹薄膜的多组等双轴预拉伸下力电耦合实验的预测

当介电高弹聚合物薄膜被施以面内等双轴预拉伸后, 受到厚度方向的电压作用时, 薄膜在力场和电场共同作用下产生大变形. 电场采用Maxwell应力分析, 力场采用橡胶弹性模型分析. 拟合这类变形的常用橡胶弹性模型主要有Neo-Hookean, Arruda-Boyce, Gent等模型. 这些模型对实验数据的定量拟合存在不同程度的偏差. 通过对实验数据的分析, 结合数学方法, 提出了一个新的自由能函数模型. 通过该模型对VHB4905介电高弹聚合物薄膜的多组等双轴预拉伸电力耦合实验进行拟合, 并以Neo-Hookean, Gent模型作为对照, 结果与实验数据拟合很好, 比对照模型的偏差明显缩小.     

Theoretical study of spin-forbidden cooling transitions of indium hydride using ab initio methods

The feasibility of spin-forbidden cooling of the In H molecule is investigated based on ab initio quantum chemistry calculations. The potential energy curves for the X~1Σ_(0~+)~+, a~3Π_~(0~-), a~3Π_(0~+), a~3Π_1, a~3Π_2, A~1Π_1, 1~3Σ_(0~-)~+, and 1~3Σ_1~+states of In H are obtained based on multi-reference configuration interaction plus the Davidson corrections method. The calculated spectroscopic constants are in good agreement with the available experimental data. In addition, the influences of the active space and spin–orbit coupling effects on the potential energy curves and spectroscopic constants are also studied. For Re of a~3Π_(0~-), a~3Π_(0~+), a~3Π_1, and a~3Π_2 states, the error from large active space is small. The potential energy curve of the A~1Π_1state is not smooth for small active space. The spin–orbit coupling effects have great influences on the potential well depth and equilibrium internuclear distance of the A~1Π state. The Franck–Condon factors and radiative lifetimes are obtained on the basis of the transition dipole moments of the a~3Π_(0~+) → X~1Σ_(0~+)~+, a~3Π_1 → X~1Σ_(0~+)~+, and A~1Π_1 → X~1Σ_(0~+)~+ transitions. Our calculation indicates that the a~3Π_1( ν'= 0) → X~1Σ_(0~+)~+(ν = 0) transition provides a highly diagonally distributed Franck–Condon factor and a short radiative lifetime for the a3Π1 state, which can ensure rapid and efficient laser cooling of In H.The proposed laser drives a~3Π_1 → X~1Σ_(0~+)~+ transitions by using three wavelengths.     

BaF radical: A promising candidate for laser cooling and magneto-optical trapping

Recently, there have been great interest and advancement in the field of laser cooling and magneto-optical trapping of molecules. The rich internal structure of molecules naturally lends themselves to extensive and exciting applications. In this paper, the radical~(138)Ba~(19) F, as a promising candidate for laser cooling and magneto-optical trapping, is discussed in detail.The highly diagonal Franck–Condon factors between the X~2Σ~+_(1/2)and A~2Π_(1/2) states are first confirmed with three different methods. Afterwards, with the effective Hamiltonian approach and irreducible tensor theory, the hyperfine structure of the X~2Σ~+_(1/2)state is calculated accurately. A scheme for laser cooling is given clearly. Besides, the Zeeman effects of the upper(A~2Π_(1/2)) and lower(X~2Σ~+_(1/2)) levels are also studied, and their respective g factors are obtained under a weak magnetic field.Its large g factor of the upper state A~2Π_(1/2) is advantageous for magneto-optical trapping. Finally, by studying Stark effect of Ba F in the X~2Σ~+_(1/2), we investigate the dependence of the internal effective electric field on the applied electric field. It is suggested that such a laser-cooled Ba F is also a promising candidate for precision measurement of electron electric dipole moment.     

中重核中单粒子与集体运动的竞争效应(英文)

从原子核的电四极跃迁强度B（E2）中可以提取出原子核集体性和单粒子性质竞争的重要信息,其中一个重要的观测量是B（E2;4₁+ →2₁+）/B（E2;2₁+ →g.s.）的比值（B_4/2）。B_4/2一般要大于1,而且对于原子核转动和振动,我们应有B_4/2=1.4和2.0,但球形半满壳核一般会有不一样的性质。这些核的性质主要受对关联效应影响。介绍了几种超出我们一般认识的奇特衰变性质。Te同位素的基态带有鲜明的振动特性,但114Te的E2跃迁性质却更符合转动性。这些性质可以通过大规模壳模型计算来描述。对于填充j=9/2轨道的半满壳核,它们的4+和6+显示出很强的辛若数部分守恒性质。这种奇特的部分守恒可以被解析证明。而且我们的计算表明辛若数部分守恒对相关的E2跃迁影响很大。对于N=90附近具有量子相变行为的核素,其B_4/2也会也表现出相似的奇异特性。The E2 transition strength, B(E2), gives particularly precise information on the competition between the collective and single-particle degree of freedom. An important observable to study the development of collectivity is the B(E2; 4₁+ →2₁+)/B(E2; 2₁+ →g.s.) (B_4/2). The B_4/2 ratio is usually greater than unity. These values are 1.4 and 2.0 for an ideal rotor and a vibrator, respectively. Whereas the seniority scheme usually leads to different behaviours. In this contribution I will show examples that contrast with our standard understanding. The yrast spectra of Te isotopes show a vibrational-like equally-spaced pattern but the few known E2 transitions show anomalous rotational-like behaviour, which cannot be reproduced by collective models. Large-scale shell model calculations reproduce well the equally-spaced spectra of those isotopes as well as the constant behaviour of the B(E2) values in 114Te. For nuclei involving protons or neutrons in j=9/2 orbitals, the partial conservation of seniority can lead to dramatic changes to the E2 decay pattern that have never been seen before. The B_4/2 ratios in quantum phase transitional nuclei around N=90 also show a similar exotic feature.     

三联吡啶钌超分子包合物及其SiO2复合纳米粒的电化学发光信号放大

利用环糊精类物质能够形成超分子包合物的性质,研究了电中性的β-环糊精（β-CD）和负电性的羧甲基-β-环糊精（CM-β-CD）与电化学发光（ECL）活性物质三联吡啶钌（Ru（bpy）₃²⁺）形成超分子包合物的能力及其对ECL的增强作用。结果表明：形成的超分子包合物能够增强Ru（bpy）₃²⁺的ECL,其中CM-β-CD具有更强的增强作用。相对于Ru（bpy）₃²⁺,CM-β-CD增强了1.42倍,而β-CD仅为1.28倍。以制备的表面电荷为负的SiO₂纳米粒为载体,考察了其对Ru（bpy）₃²⁺超分子包合物的吸附能力。结果表明,与Ru（bpy）₃²⁺的CM-β-CD超分子包合物相比,SiO₂纳米粒载体对Ru（bpy）₃²⁺的β-CD 超分子包合物表现出了更强的吸附能力。制备了ECL信号放大能力最强的β-CD-Ru（bpy）₃²⁺超分子包合物的SiO₂复合纳米粒。     

Non—spectator Diquark Effiects on Lifetimes of Λb,Ωb（＊） and Weak Decay Rates of ∑bΞb（＊）

The difference of τB and τAb indicates the role of the light flavors,We calculate the lifetinmes of B-meson and Λb based on the weak effective Hamiltonian while assuming the heavy baryon is constructed by a heavy b-quark and a diquark containing two light quarks.In this scenario,we use the information of the measured ratio τΛb/τB as input to predict rates of the inclusive weak decays of ∑b^(*) and Ξb^(*) into non-bottom final states.We find that these rates of ∑b^(*) and Ξb^(*) are much larger than those of B-mesons and Λb,We also give the predictions for the lifetimes of Ωb and Ω,Pheomenological implication of our result is discussed.     

Pion-Rotational Nucleus Scattering and the Interacting Boson Model

A procedure of combining the medium energy scattering theory in the eikonal approximation with the interacting boson model (IBM) is proposed to study the pion-rotational nucleus scattering. The channel coupling effects in the excitation of nuclear collective state with π^- and π⁺ elastic and inelastic scattering are analyzed. The calculated cross sections for the excitation of 2₁⁺ state of ¹⁵²Sm agmree with the experimental data quite well.     

Ω＋Ω→（ΩΩ）Jπ=0＋＋X Cross section Calculation

The cross sections of Ω+Ω→(ΩΩ)_J^π=0⁺+X are studied by using an effective Hamiltonian method. The results are σ_{Ω+Ω→(ΩΩ)0⁺+γ}=0.03～0.16×10^-29 cm² for p_Ω=100～400 MeV, and the cross sections of η production are about 10^-28 cm² for p_Ω > 880 MeV.     

Pion-Nucleus Scattering and the Interacting Boson Model

A procedure of combining the medium energy scattering theory in the Eikonal approximation with the interacting boson model is proposed to study the pion-nucleus scattering. The channel coupling effects in the excitation of nuclear collective state with ρ^- and ρ⁺ elastic and inelastic scattering are analyzed. The calculated cross sections for the excitation of 2₁⁺ state of ²¹⁸Sn agree with experimental data quite well.     

Energy Spectra and g Factors of α-A1203:Cr3+ and α-A1203:Mn4+

By diagonalizing the complete d³ energy matrix in a trigonally distorted cubicfield and using the wavefunctions from it, unified calculations of the whole energy spectrum as well as the g factors of the ground state and t₂^{3 2} E excited states for α-A1₂0₃:Cr³⁺ and α-A1₂0₃:Mn⁴⁺ have been carried out respectively. A11 the calculated results are in very good agreement with the experimental data. The comparison between the results of the two crystals has been made, which demonstrates that the covalency of α-A1₂0₃:Mn⁴⁺ is stronger than the one of α-A1₂0₃:Cr³⁺. For the zero-field splittings of the ground state and t₂^{3 2} E , their physical origins are revealed; the comparison and analysis of their values of the two crystals have been made.     

One- and Two-Mode Combination Squeezing Operator for Two Harmonic Oscillators with Coordinate-Momentum Coupling

By virtue of the technique of integration within an ordered product of operators, we derive the normal ordering expansion of a one- and two-mode combination squeezing operator for two harmonic oscillators with coordinate- momentum coupling. It turns out that this squeezing operator just diagonalizes the Hamiltonian H=p^21/2m1＋m1ω^21x^21/2＋p^222m2＋m2ω^22x^22/2-λx2p1 so its ground state is a one- and two-mode combination squeezed state. Quantum fluctuation in the ground state is calculated.     

AlH~+离子5个Λ-S态和10个?态的光谱性质以及激光冷却的理论研究

利用考虑Davidson修正的内收缩多参考组态相互作用(icMRCI+Q)方法结合相关一致基组aug-ccpV6Z计算了AlH~+离子前两个离解极限对应的5个Λ-S态和10个?态的势能曲线.为了提高势能曲线的可靠性和精确性,计算中考虑了自旋轨道耦合效应、芯电子价电子相关和标量相对论修正以及将势能外推至完全基组极限.基于得到的势能曲线,获得了束缚和准束缚的4个Λ-S态和8个?态的光谱常数和振动能级,与已有的实验结果符合.计算了2(1/2)→X~2Σ_(1/2)~+和A~2Π_(3/2)→X~2Σ_(1/2)~+跃迁的跃迁偶极距.利用计算的精确的势能曲线和跃迁偶极矩,获得了2(1/2)~(第一势阱)(υ′=0, 1)→X~2Σ_(1/2)~+(υ′′)和A~2Π_(3/2)(υ′=0, 1)→X~2Σ_(1/2)~+(υ′′)跃迁的高度对角化分布的Franck-Condon因子(f_(00)和f_(11))和大的振动分支比;预测了2(1/2)~(第一势阱)(υ′=0, 1)和A~2Π_(3/2)(υ′=0, 1)态短的自发辐射寿命和窄的辐射宽度,这适合于AlH~+离子的快速激光致冷.所需的3束激光冷却波长都在紫外区域.这些结果表明了激光冷却AlH~+离子的可行性.此外,评估了自旋轨道耦合效应对光谱常数、振动能级和激光冷却AlH~+离子的影响.     

LiGd(W_yMo_(1-y))_2O_(8-x/2)F_x∶Eu~(3+)红色荧光粉的制备和发光特性

采用高温固相法制备了LiGd(W_yMo_(1-y))_2O_(8-x/2)F_x∶0.4Eu~(3+)(x=0~1,y=0~1)系列白光LED用红色荧光粉。通过扫描电子显微镜、X射线衍射仪、红外光谱仪、荧光光谱仪对荧光粉的形貌、结构、光学性能进行了表征。结果表明,Eu~(3+)、F-和WO_4~(2-)的掺杂没有改变LiGd(MoO_4)_2的四方晶系白钨矿结构;F~-和WO_4~(2-)最佳掺杂量分别为x=0.6,y=0.4。在396 nm激发下,LiGd(W_(0.4)Mo_(0.6))_2O_(7.7)F_(0.6)∶0.4Eu~(3+)的发光强度比未掺杂样品提高了60%,量子效率可达66.23%。当温度升高至100℃时,样品的发射强度降为25℃时的76.6%。在460 nm激发下,样品的最强窄带发射峰位于617 nm处,归属于~5D_0→~7F_2跃迁,色坐标为(0.649 9,0.346 3)。5D0能级的荧光寿命曲线遵循单指数规律衰减,随着F-掺杂浓度的增加,5D0能级的荧光寿命不断增加,归因于低声子能量的F-掺入有效减小了能量的无辐射跃迁概率。所制备的LiGd(W_(0.4)Mo_(0.6))_2O_(7.7)F_(0.6)∶0.4Eu~(3+)荧光粉有望应用于白光LED。     

Four-Particle Entangled State Representation and Its Squeezing Transformation

The four-particle EPR entangled state | p,χ₂,χ₃,χ₄〉is constructed. The corresponding quantum mechanical operator with respect to the classical transformation p→e^λ₁p, χ₂→ e^λ₂χ₂, χ₃→e^λ₃χ₃, and χ₄→e^λ₄χ₄ in the state |p,χ₂ ,χ₃ ,χ₄〉is investigated, and the four-mode realization of the SU(1,1) Lie algebra as well as the corresponding squeezing operators are presented.     

Supersymmetric Electroweak Corrections to the Decay of the Heavy Chargino into the Light Chargino and Z Boson

The supersymmetric electroweak corrections to the partial width of the decay \tilde{χ}₂⁺→ Z⁰\tilde{χ}₁⁺, including the contributions from the third generation quarks and squarks, are presented within the minimal supersymmetric standard model. With the reasonable parameters sets, which open this decay channel kinematically, the relative corrections can reach the value of ～ -6%. Therefore they should be taken into consideration for the precise experimental measurement at future colliders.     

Equilibrium dynamics of the sub-Ohmic spin-boson model under bias

Using the bosonic numerical renormalization group method, we studied the equilibrium dynamical correlation function C(ω) of the spin operator σ_z for the biased sub-Ohmic spin-boson model. The small-ω behavior C(ω) ∝ω~s is found to be universal and independent of the bias ε and the coupling strength α(except at the quantum critical point α = αc and ε = 0). Our NRG data also show C(ω) ∝χ~2ω~s for a wide range of parameters, including the biased strong coupling regime(ε = 0 and α α_c), supporting the general validity of the Shiba relation. Close to the quantum critical point αc,the dependence of C(ω) on α and ε is understood in terms of the competition between ε and the crossover energy scale ω_0~*of the unbiased case. C(ω) is stable with respect to ε for ε《ε~*. For ε》ε~*, it is suppressed by ε in the low frequency regime. We establish that ε~*∝(ω_0~*)~(1/θ)holds for all sub-Ohmic regime 0≤s 1, with θ = 2/(3s) for 0 s≤1/2 and θ = 2/(1 + s) for 1/2 s 1. The variation of C(ω) with α and ε is summarized into a crossover phase diagram on the α–ε plane.     

A Possible Generalization of Jaynes-Cummings Model with Degenerate Spectrum

We propose a generalized Jaynes-Cummings model (JCM) for three two-level atoms and three-mode radiation field with the interaction being H₁=λ(a₁⁺a₂⁺σ_1-σ_2-+a₂⁺a₃⁺σ_2-σ_3-+a₁⁺a₃⁺σ_1-σ_3-+H.C.). This model is characteristic of possessing partly degenerate spectrum. Some transition process of this system is calculated.