Description of Staggering Phenomenon of the Superdeformed Bands in SUq(2) Symmetry

The staggering phenomenon of the superdeformed bands ¹⁴⁹Gd(1),¹⁴⁸Gd(6) and ¹⁴⁸Eu(1) is analyzed with a SU_q(2) rotational spectroscopy expression. When the spin of the head of band is chosen properly,the calculating bifurcation of ΔI=4 is agreement with that extracted from experiment.     

A New Expression for Nuclear Rotational Spectra

A new formula, which is derived from a deformed rotor model for describing nuclear rotational spectra, is analyzed. The ground band of most even-even rare-earth and actinide nuclei are accurately reproduced using a damped nonlinear least-square fitting procedure for determining parameters of the theory. The results show that energy spectra obtained from a deformed rotor model are more accurate than those from a three-parameter formula based on perturbation theory.     

A Two-Parameter Deformed Two-Dimensional Interacting Boson Model With Uqp(U3)Uqp(U2)Uqp(SO2) Symmetry

A two-parameter deformed two-dimensional interacting boson model with U_qp(U₃) U_qp(U₂) U_qp(SO₂)symmetry is constructed.It is found that the energy spectrum and transition matrix elements depend very sensitively on the second parameter of deformation.     

Squeezing Property of the States Generated by the Excitation on the SUq(1,1) Even and Odd q-Coherent States

The squeezing property of states generated by the excitation on the SU_q(1,1) even and odd q coherent states (a+mqα>eq and a+m qα>oq) is numerically studied. It is shown that for small q, the state a+m qα>eq and state a+mqα>oq can exhibit strong q squeezing, and as r² increases the q squeezing function Δe1(Δo1) exhibits a wonderful oscillating phenomenon of increasing amplitude and increasing period. As m increases and q decreases, the amplitude of Δe1(Δo1) increases greatly. As q decreases, the period of Δe1(Δo1) increases but is independent of m.     

h-Miura Transformation in the DYh(sl2)k Case

The h-analogue of the Sugawara operater is constructed for the Yangian double with central extension in the sl₂ case.Using the free fields realization of the quantum currents,the h-analogue Miura transformation is obtained.     

The angleICI Bending Satellites in the Millimeter-Wave Rotational Spectra of CH(2)I(2) and CD(2)I(2)

Rotational transitions in the first four excited states of the low-frequency angleICI bending mode, nu(4), have been assigned in the mm-wave rotational spectra of CH(2)I(2) and of CD(2)I(2). Measurements of transition frequencies, made over the frequency region 167-326 GHz and for J" up to 190, allowed determination of sextic level spectroscopic constants for all states. The changes in spectroscopic constants with vibrational excitation show very small anharmonicity, in spite of the very low frequency of this mode (121 cm(-1)). Vibrational excitation affects the moments of inertia in such a way that the planar moment P(b), about the plane perpendicular to both angleICI and angleHCH, is practically invariant. Vibrational change in P(c), the moment along the principal axis in the HCH plane and perpendicular to the angleHCH bisector, has been successfully reproduced with an ab initio harmonic force field so that there is no discernible vibrational change in angleHCH on excitation of angleICI. Finally, the change in P(a) leads to estimated vibrational change of +0.12 degrees in the value of angleICI itself. Copyright 2000 Academic Press.     

CdGd2(WO2)4单晶的顺磁共振谱研究

通过粉末XRD测定了CdGd₂(WO₂)₄单晶的晶格常数,由σ- T和ESR实验得出晶体具有顺磁性,但又具有磁各向异性,探讨了晶体的磁各向异性与晶体结构的关系,计算了各向异性g²张量,所得结果和实验符合甚好.      

Superconductivity in Hole-Doped （S1-xKx）Fe2As2

A series of layered （Sr1-xKx）Fe2As2 compounds with nominal x = 0-0.40 are synthesized by solid state reaction method. Similar to other parent compounds of iron-based pnictide superconductors, pure SrFe2As2 shows a strong resistivity anomaly near 210 K, which was ascribed to the spin-density-wave instability. The anomaly temperature is much higher than those observed in LaOFeAs and BaFe2As2, the two prototype parent compounds with ZrCuSiAs- and ThCr2Si2-type structures. K-doping strongly suppresses this anomaly and induces superconductivity. Like in the case of K-doped BaFe2As2, sharp superconducting transitions at Tc ～ 38 K is observed. We perform the Hall coefficient measurement, and confirm that the dominant carriers are hole-type. The carrier density is enhanced by a factor of 3 in comparison to F-doped LaOFeAs superconductor.     

The Rotational Spectra, Isotopically Independent Parameters, and Interatomic Potentials for the X(1)(2)Pi(3/2) and X(2)(2)Pi(1/2) States of BrO

Observations of the rotational spectrum of BrO have been extended to include vibrational levels up to v = 8 in the X(1)(2)Pi(3/2) and v = 7 in the X(2)(2)Pi(1/2) states. The rotational spectra of isotopically enriched Br(18)O, X(1), v = 0, 1 and X(2), v = 0 have been observed as well. The spectra of all four isotopic species have been fit to a Hamiltonian in which the parameters have fixed isotopic ratios. An extensive set of isotopically independent parameters has been determined. Interatomic potentials have been derived for both the X(1) and X(2) states. The hyperfine constants and their vibrational dependencies have been determined more precisely and several of them have been determined for the first time. These are interpreted in terms of the electronic structure of the molecule. The isotope relations among the constants have provided a means of decorrelating the electron spin-rotation constant gamma from the fine-structure centrifugal distortion constant, A(D), and have allowed the first determination of an effective value for gamma. Copyright 2001 Academic Press.     

Theoretical Investigation of Femtosecond-Resolved Photoelectron Spectra of the Li2 Molecule

The time-dependent quantum wave packet method is used to investigate the dynamics for the Li2 molecule, and the time-resolved photoelectron spectra （TRPES） of the Li2 molecule are calculated. At the short delay time, the particular phenomenon of TRPES with four peaks is qualitatively interpreted in a dressed state picture by analyzing wave packet motion on light-induced potential （LIP）. The significant difference in the electronic structure of E1∑g^＋ between the inner and outer turning points has an impact on the TRPES. The control for the first excited state A1∑u^＋ of the initial wave packet is discussed.     

The Rotational Spectra of H2CCSi and H2C4Si

The microwave rotational spectra of two singlet chains H₂CCSi and H₂C₄Si, have been observed in a pulsed supersonic molecular beam by Fourier transform microwave spectroscopy. Following detection of the singly substituted rare isotopic species and D₂CCSi, an experimental structure (r₀) has been determined to high accuracy for H₂CCSi by isotopic substitution. In addition, the rotational transitions of the ²⁹Si and the two ¹³C isotopic species of H₂CCSi exhibit nuclear spin-rotation hyperfine structure. The component of the spin-rotation tensor along the a-inertial axis is abnormally large for each of these isotopic species, especially for that with ²⁹Si, where the magnitude of C_aa is in excess of 700 kHz.     

A Comprehensive Analysis for Eight Formulas for Rotational Spectra

All the data now available for the ground rotational bands of actinide even-even nuclei and rare-earth even-even nuclei are analyzed with eight formulas for rotational spectra.It can be seen from calculated results that the four-parameter I(I+1) expansion,the four-parameter ω² expansion and W-Z formula can fit the GRB's of well-deformed unclei very well.     

Irreducible Representations of Quantum Lie Superalgebra SLq(2/1)

In this paper,some generators of SL_q(2/1),satisfying the Serre-like relations,can be considered as 1/2 rank tensor-like operators.The reduced matrix elements of them can be calculated by a set of recurrent formula.Thus th irreducible representations of SL_q(2/1) may be completely determined.     

Two Dimensional Cyclic Representations of Uq(sl2)and 8-Vertex Ising Model

We give explicitly the 2-dimensional cyclic representations of quantum algebra U_q(sl₂)with central extension.The intertwiner for tensor representations in different ordersis constructed with C-G coefficients.This intertwiner is shown to be the R -matrix for eight vertex Ising model.     

Ar-D232S复合物的转动光谱理论研究

对Ar-D₂³²S转动光谱进行了理论研究．该体系的分子间势能面是由最近报道的Ar-D₂³²S体系的从头算三维势能面转换而来．通过采用径向离散变量表象与角度有限基组表象相结合的方法和Lanczos算法,计算了复合物的转动能级和波函数．结果表明,理论计算得到的转动跃迁频率和结构参数与实验值吻合较好     

FUNDAMENTAL PROBLEMS OF SU(2)t WZW MODELS

In this paper,we give a solution to fundamental problems of Wess-Zumino-Witten model for the case j₃=1 and the method of solving the fundamental problems for the general case.We find also the explicit connection between the crossing matrix of SU(2)_t WZW model and the braid matrix of SL(2,q) quantum group,the latter is just the quantum Racah coefficent.