TEM01模式激光对两能级原子的作用力研究

推导了两能级原子在稳态和小速度一阶微扰近似下的受力矢量方程，并分析表明ＴＥＭ０１模光场以原子的作用力中存在旋涡力，对在大正失谐δ〉〉Ω０〉〉Г和ｚ〈〈ｚ０＝ｋｗ＾２／λ条件下的ＴＥＭ０１模行波和驻波场中原子的受力进行了分析，对行波场，自发辐射对原子运动的影响很大，但在ｒ〈〈λ区域内原子受到横向囚禁力；对驻波场，自发辐射的影响可以忽略，考虑在ｚ方向波长范围内原子的平均受力得到的结论为：在横向，除了有     

The TEM characterization of the lamellar structure of osteoporotic human trabecular bone

The lamellar structure of osteoporotic human trabecular bone was characterized experimentally by means of transmission electron microscopy (TEM). More specifically, the TEM was used to determine if trabecular bone exhibits similar lamellar structural motifs as cortical bone by analyzing unmineralized, mineralized and demineralized bone, and to study the influence of the osteocyte network on the lamellar structure of osteoporotic trabecular bone. Comparison with normal trabecular bone is included. This paper summarizes partial results of a larger study, which addressed the characterization of the hierarchical structure of normal versus osteoporotic human trabecular bone [Rubin, M.A., 2001. Multiscale characterization of the ultrastructure of trabecular bone in osteoporotic and normal humans and in two inbred strains of mice. MS Thesis, Georgia Institute of Technology.] at several structural scales.     

Dissipation of System and Atom in Two-Photon Jaynes–Cummings Model with Degenerate Atomic Levels

A method of perturbative expansion of master equation is employed to study the dissipative properties of system and of atom in the two-photon Jaynes–Cummings model (JCM) with degenerate atomic levels. The numerical results show that the degeneracy of atomic levels prolongs the period of entanglement between the atom and the field. The asymptotic value of atomic linear entropy is apparently increased by the degeneration. The amplitude of local entanglement and disentanglement is suppressed. The better the initial coherence property of the degenerate atom, the larger the coherence loss.     

Beta-decay of 71Co and 73Co

A decay spectroscopy study of the neutron-rich cobalt isotopes has been performed using fragmentation of a ⁸⁶Kr³⁶⁺ beam and the new LISE2000 spectrometer at GANIL. For ⁷¹Co and ⁷³Co, the -delayed radiation has been observed for the first time, and the half-lives were found to be 79(5) ms and 41(4) ms, respectively. Features of the decay are discussed qualitatively in terms of nuclear models.     

Maximally aligned states in 99Ag

Excited states of ⁹⁹Ag were populated via the ⁵⁰Cr + ⁵⁸Ni (261 MeV) reaction using the NORDBALL detector array equipped with charged-particle and neutron detector systems for reaction channel separation. On the basis of the measured γγ-coincidence relations and angular distribution ratios a significantly extended level scheme has been constructed up to E _x ∼ 7.8 MeV and I = 35/2. The experimental results were described within the framework of the shell model. Candidates for states fully aligned in the πg _9/2 ^-3ν(d _5/2, g _7/2)² valence configuration space were found at 4109 and 6265 keV. Received: 18 June 2002 / Accepted: 11 October 2002 / Published online: 4 February 2003 RID="a" ID="a"e-mail: sohler@atomki.hu Communicated by J. ?yst?     

The strength of octupole correlations in neutron-rich Xe isotopes

Excited levels in ¹⁴⁰Xe and ¹⁴²Xe nuclei, populated in the spontaneous fission of ²⁴⁸Cm, were studied by means of prompt γ-ray spectroscopy, using EUROGAM2 array. We report the first observation of an octupole band in ¹⁴²Xe and extend the octupole band in ¹⁴⁰Xe. Level schemes of ¹⁴⁰Xe and ¹⁴²Xe obtained in this work show patterns characteristic of ocupole-vibrational bands. Properties of octupole bands in Xe isotopes indicate that octupole correlations in these nuclei are lower than in the corresponding Ba nuclei. The electric dipole moment of ¹⁴²Xe was found to be larger than in other Xe isotopes, contrary to theoretical predictions. This may be due to the special role of the N = 88 neutron number. Received: 18 November 2002 / Accepted: 15 December 2002 / Published online: 25 February 2003 RID="a" ID="a"e-mail: urban@fuw.edu.pl Communicated by D. Schwalm     

New investigation of the decay of the high-spin isomer in 151Er

The decay of the T _1/2 = 420 ns isomer in ¹⁵¹Er has been reinvestigated. The multipolarities of the decaying transitions have been established by measuring the electron conversion coefficients. An I ^π = 67/2⁻ assignment is proposed for this isomer with a π[h ₁₁^2/4 d ₃^2/1 d ₅^2/−1]⊗ν[f _7/2 h _9/2 h ₁₁^2/−1] configuration.     

引入反比相关双曲余弦平方势描述超晶格量子阱的电子跃迁

 鉴于“方形”势阱过于简单和理想，引入了反比相关双曲余弦平方势描述超晶格量子阱中的电子运动行为。在量子力学框架内，把电子的Schrodinger方程化为了超几何方程, 并以Ga^1-xAl^xAs-GaAs- Ga^1-xAl^xAs量子阱为例计算了电子的带内跃迁和带间跃迁。结果表明，能级数目和跃迁能量与阱深、阱宽等系统参数有关，只需适当调节这些参数就可望实现对超晶格量子阱光电特征的调节与控制。