锶Sr,钡Ba和镭Ra的单光子电四极矩光谱跃迁的理论研究

用带有Ｂｒｅｉｔ和ＱＥＤ修正的全相对论多组态Ｄｉｒａｃ－Ｆｃｃｋ平均能级（ＭＣＤＦ－ＡＬ）模型,计算了碱土金属Ｓｒ、钡Ｂａ和镭Ｒａ的单光子电四极矩＾１Ｄ－＾１Ｓ跃迁的光谱能量间隔,最大跃迁几率和振子强度。计算中考虑了重要的相对论效应、电子关联效应和核的有限体积效应,所得的结果与国外早期发表的结果进行了比较,此外还首次从理论上预言了镭Ｒａ的单光子电四极矩＾１Ｄ－１Ｓ光谱跃迁。     

NH4Cl作助熔剂合成CaS：Ce的光谱特性及其浓度效应

以ＮＨ４Ｃｌ作助溶剂，碳还原硫酸钙的方法合成了ＣａＳ：Ｃｅ。在紫外光激发下，ＣａＳ：Ｃｅ中存在着Ｃｅ＾３＋的＾２Ｄ－＾２Ｆ５／２（５００ｎｍ）和＾２Ｄ－＾２Ｆ７／２（５５０ｎｍ）跃迁发射，但在蓝色光激发下，只有波峰为５３２ｎｍ半宽度为９２ｎｍ的宽带发射。当Ｃｅ＾３＋的浓度为０．０７５ｍｏｌ％时，＾２Ｄ－＾２Ｆ５／２跃迁发射强度与＾２Ｄ－＾２Ｆ７／２跃迁发射强度相等，而５３２ｎｍ发射猝灭。     

XPS研究聚苯胺的竞争掺杂行为

采用Ｘ射线光电子能谱（ＸＰＳ）方法对不同反应体系下化学合成的聚苯胺（ＰＡＮ）的结构和掺杂状况进行了研究。发现盐酸（ＨＣｌ）掺杂的聚苯胺在样品后处理过程中易发生脱掺杂行为;在十二烷基苯磺酸钠（ＳＤＢＳ）和盐酸共存体系下合成聚苯胺时,对阴离子ＤＢＳ＾－和Ｃｌ＾－发生竞争掺杂行为。结果表明ＤＢＳ＾－与带正电荷聚苯胺链结合,起到了掺杂和诱导聚苯胺可溶性的作用,它的Ｎ１ｓ和Ｓ２ｐ谱图与单独采用十二烷基苯磺酸     

（Ba1—xKx）BiO3芯态能级随组份的变化

本用第一原理的ＬＤＦ－ＬＭＴＯ－ＡＳＡ方法，以超元胞Ｂａ４Ｂｉ４Ｏ１２，（Ｂａ３Ｋ）ＢｉＯ１２，（ＢａＫ）Ｂｉ２Ｏ６，（ＢａＫ３）Ｂｉ４Ｏ１２，Ｋ２Ｂｉ２Ｏ６五种“样本”计算由于Ｂｉ＾＋３和Ｂｉ＾＋５二种价态以及Ｋ掺杂引起各芯态能级化学位移的变化，“样本”的电子结构与实验相符，即Ｂａ４Ｂｉ４Ｏ１２是ｇ＝－２．０ｅＶ的半导体，（Ｂａ３Ｋ）Ｂｉ４Ｏ１２ｊ Ｅｇ＝１．６ｅＶ其价带顶有不量空穴的半导体，     

动态MOCVD法在Ag／Ni复合基体上连续制备YBCO超导带

本报道用ＭＯＣＶＤ方法在以１５ｃｍ／ｈｒ速度连续走带的Ａｇ／Ａｉ复合基体上制备ＹＢＣＯ超导带的结果。所有ＹＢＣＯ超导带的Ｊｃ值为１．３×１０＾４Ａ／ｃｍ＾２；样品主相为ＹＢＣＯ１２３，呈强烈ｃ－轴取向，其衍射峰的摇摆曲线半高宽约为２．８°；另外，还含有少量Ｙ２ＢａＣｕＯ５和ＢａＣｕＯ２杂相，本还用ＳＥＭ和ＥＤＸ对样品沉积层进行了观测分析。     

铁-硒二元团簇离子的产生和紫外光解

用激光直接溅射的方法产生了铁－硒二元团簇,并用串级飞行时间质谱仪研究了二元团簇的组份和光解规律。一组谱中组成ＦｅｎＸＳｅｎ＾＋,ＦｅｎＳｅｎ－１＾＋和ＦｅｎＳｅｎ＾－、ＦｅｎＳｅｎ＋１＾－是二元团簇的结构骨架和稳定组份。团簇正离子ＦｅｎＳｅｎ＾＋的紫外光解结果表明,光解产物主要为一级谱中丰度较大的离子,用密度泛函方法（ＤＦＴ）优化了Ｆｅ２Ｓｅ２＾＋的几何结构,并计算了其光解通道,能较好地解释光解的     

宽禁带II—VI族化合物半导体薄膜及超晶格的外延生长及特性研究

介绍了宽禁带ＩＩ－ＶＩ族化合物半导体ＺｎＳｅ，ＺｎＳＳｅ和ＺｎＣｄＳｅ外延膜及它们的超晶格的分子束外延生长。用Ｘ射线衍射法（ＸＲＤ）和光致发光（ＰＬ）法分别对其结构特性和光学特性进行了研究。尤其是对超晶格样品所进行的温度变化的ＰＬ研究，得出了对于ＺｎＳｅ／ＺｎＳＳｅ超晶格，其激子激活能（Ｅａｃｔ）仅为１７ｍｅＶ，我们用ＺｎＳｅ／ＺｎＳＳｅ导带不连续较小来解释这个结果。而对于ＺｎＣｄＳｅ／ＺｎＳｅ超     

掺Ce的Y－Ba－Cu－O体系成相的拉曼光谱分析

掺Ｃｅ的Ｙ－Ｂａ－Ｃｕ－Ｏ体系成相的拉曼光谱分析许存义，左健，王跃（中国科学技术大学结构分析开放研究实验室合肥２３００２６）ＳｔｕｄｙｏｎＴｈｅＲａｍａｎＳｐｅｃｔｒｕｍｏｆＣｅ－ｄｏｐｅｄＹ－Ｂａ－Ｃｕ－ＯＳｙｓｔｅｍ￥ＣｕｎｙｉＸｕ；ＪｉａｎＺｕ...     

氧化硅包敷对铁黄脱水过程的影响

本文采用ＤＴＡ、ＴＧ、ＨＴＸＴＤ和ＴＥＭ研究了ＳｉＯ２包敷ａ－ＦｅＯＯＨ粒子的脱水过程。从ＤＴＡ和ＴＧ曲线算得的动力学参数表明，ＳｉＯ２包敷ａ－ＦｅＯＯＨ粒子的脱水过程近似为一级反应，其活化能大于未处理的ａ－ＦｅＯＯＨ粒子的活化能。     

He（2^3S）与N2O（X）Penning电离中的N2O^＋（A^2Σ^＋）生成速率及相…

在分子束条件下测量了Ｈｅ（２＾３Ｓ）＋Ｎ２Ｏ（Ｘ）→Ｎ２Ｏ＾＋（Ａ＾２Σ＾＋）＋Ｈｅ（＾１Ｓｏ）＋ｅ＾－反应的Ｐｅｎｎｉｎｇ电离光学光谱，求得了Ｎ２Ｏ＾＋（Ａ＾２Σ＾＋）态的初生态相对振动布居。以Ｈｅ（２＾３Ｓ）＋Ｎ２（Ｘ）→Ｎ＾＋２（Ｂ＾２Σ＾＋ｕ）＋Ｈｅ（＾１Ｓｏ）＋ｅ＾－为参考反应，测量了Ｈｅ（２＾３Ｓ）＋ＢＮ２Ｏ＾＋（Ａ＾２Σ＾＋）＋Ｈｅ（＾１Ｓｏ）＋ｅ＾－反应的速率常数ＫＮ２Ｏ＾＋（Ａ）     

Studies of low-lying states of even-even Xe isotopes within the nucleon pair approximation

We study the relevance of nucleon pairs with higher spins, in addition to spin-zero and spin-two pairs (i.e., S D pairs), in low-lying states of even-even Xe nuclei. By including those higher-spin pairs in our configuration, we recalculate energy level schemes, elec trical quadrupole moments, magnetic moments and electric quadrupole transition rates, for low-lying states of even-even 128-142Xe nuclei. The agreement between our calculated results and the experimental data is substantially improved in compari...     

Gamma-gamma angular correlation studies in97Tc

The rapid rotation of even-even nuclei is investigated. The characteristic properties of Zn, Mo, Sn, Te, Xe, Ba, Ce and Nd isotopes for high spin are presented. Microscopic calculations are based on the modified oscillator average potential including the quadrupole axial (?) and nonaxial (γ) deformations. The potential energy surfaces of the nuclei are obtained by the shell correction method. The nuclear shape determined by the potential energy surface as a function of angular momentum is predicted.     

High spin structures of 122Xe

High — spin states in ¹²²Xe have been investigated by γ ? γ coincidence measurements using the EUROGAM array. The reaction ⁹⁶Zr(³⁰Si,4n)¹²²Xe at a beam energy of 135 MeV was used to populate states of ¹²²Xe. The level scheme has been extended up to ～ 13.5 MeV and also enriched as compared to previous studies. New structures of competing dipole to quadrupole transitions have been observed. Experimental B(M1)/B(E2) ratios have been extracted for these structures and compared with theoretical estimates. They have also been compared with similar structures in Xe, Ba and Ce nuclei.     

Nuclear spin resonance of (129)Xe doped with O(2)

Spin-lattice relaxation of (129)Xe nuclei in solid natural xenon has been investigated in detail over a large range of paramagnetic O(2) impurity concentrations. Direct measurements of the ground state magnetic properties of the O(2) are difficult because the ESR (electron spin resonance) lines of O(2) are rather unstructured, but NMR measurements in the liquid helium temperature region (1.4-4 K) are very sensitive to the effective magnetic moments associated with the spin 1 Zeeman levels of the O(2) molecules and to the O(2) magnetic relaxation. From these measurements, the value of the D[Sz(2)-(1/3)S(2)] spin-Hamiltonian term of the triplet spin ground state of O(2) can be determined. The temperature and magnetic field dependence of the measured paramagnetic O(2)-induced excess line width of the (129)Xe NMR signal agree well with the theoretical model with the spin-Hamiltonian D=0.19 meV (2.3 K), and with the reasonable assumption that the E[S(x)(2)-S(y)(2)] spin-Hamiltonian term is close to 0 meV. An anomalous temperature dependence between 1.4 K and 4.2K of the (129)Xe spin-lattice relaxation rate, T(1n)(-1)(T), is also accounted for by our model. Using an independent determination of the true O(2) concentration in the Xe-O(2) solid, the effective spin lattice relaxation time (which will be seen to be transition dependent) of the O(2) at 2.3 K and 0.96 T is determined to be approximately 1.4 x 10(-8)s. The experimental results, taken together with the relaxation model, suggest routes for bringing highly spin-polarized (129)Xe from the low temperature condensed phase to higher temperatures without excessive depolarization.     

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     

Er，Yb和Hf同位素的基态占有率（英文）

应用严格求解的Nilsson 平均场加推广对力模型,在同时考虑质子-质子和中子-中子间对力相互作用的情况下,对稀土区的152-164Er,154-166Yb 和156-168Hf 核素的结合能、奇偶能差、低激发态转动惯量等基态性质进行系统的统一描述。通过计算结果与实验数值比较分析显示,对力相互作用在阐明以上核素能谱的基态性质中起到了关键的作用。应用拟合上述物理量所确定的模型参数,对156-162Yb 核素基态中价核子配成角动量J = 0,1,… ,12的价核子对占有率的计算结果显示,配成角动量为偶数价核子对的占有率远远高于配成角动量为奇数价核子对的占有率,其数值结果揭示了配成角动量为S,D和G的价核子对在所考虑的核素基态性质中占主导地位。The Nilsson mean-field plus extended-pairing model for deformed nuclei is applied to describe the ground-state properties of selected rare-earth nuclei. Binding energies, even-odd mass differences, moments of inertia for the ground-state band of 152-164Er, 154-166Yb, and 156-168Hf are calculated systematically in the model employing both proton-proton and neutron-neutron pairing interactions. In comparison with the corresponding experimental data, it is shown that for these rare-earth nuclei, pairing interaction is crucial in elucidating the properties of the ground state. With model parameters determined by fitting the energies of these states, ground-state occupation probabilities of valence nucleon pairs with angular momentum J =0,1, …,12 for even-even 156-162Yb are calculated. It is inferred that the occupation probabilities of valence nucleon pairs with even angular momenta are much higher than those of valence nucleon pairs with odd angular momenta. The results clearly indicate that S, D, and G valence nucleon pairs dominate in the ground state of these nuclei.     

Studies of low-lying states of even-even Xe isotopes within the nucleon pair approximation

We study the relevance of nucleon pairs with higher spins, in addition to spin-zero and spin-two pairs (i.e., SD pairs), in low-lying states of even-even Xe nuclei. By including those higher-spin pairs in our configuration, we recalculate energy level schemes, electrical quadrupole moments, magnetic moments and electric quadrupole transition rates, for low-lying states of even-even ^128–142Xe nuclei. The agreement between our calculated results and the experimental data is substantially improved in comparison with previous studies.     

Matrix Elements in Fermion Dynamical Symmetry Model

In a neutron-proton system, the matrix elements of the generators for SO(8)×SO(8) symmetry are constructed explicitly, and with these matrix elements the low-lying excitation spectra obtained by diagonalization are presented. The excitation spectra for SO(7) nuclei Pd and Ru isotopes and SO(6) r-soft rotational nuclei Xe, Ba, and Ce isotopes are calculated, and comparison with the experimental results is carried out.     

Matrix Elements in Fermion Dynamical Symmetry Model

In a neutron-proton system, the matrix elements of the generators for SO(8) × SO(8) symmetry areconstructed explicitly, and with these matrix elements the low-lying excitation spectra obtained by diagonalization arepresented. The excitation spectra for SO(7) nuclei Pd and Ru isotopes and SO(6) r-soft rotational nuclei Xe, Ba, andCe isotopes are calculated, and comparison with the experimental results is carried out.     

A～130过渡区核的高自旋态研究

评述了Ａ～１３０过渡区Ｉ、Ｘｅ、Ｃｓ和Ｂａ核的高自旋核结构研究．在这些核中观测到的极为丰富的核结构现象,如质子中子转排竞争、形状共存、带终结、带交叉延迟、Ｓｉｇｎａｔｕｒｅ反转和八极关联等与这些核的价质子、价中子都位于ｈ１１／２支壳及这些核易产生γ形变有关. The studies of high spins states of A ～130 transitional I,Xe,Cs and Ba nuclei are reviewed. The variety of nuclear structure, such as proton neutron alignment competition, shape coexistance, band termination, crossing delay, signature inversion, octupole correlation, etc. observed in these nuclei is closely related to that both the valence proton and neutron of these nuclei are located in the h 11/2 subsell and the nuclei are soft against the γ deformation.