偶偶Cd同位素核的形变HF态及负宇称带研究

将具有正宇称的轨道空间扩大到包含具有负宇称的1h_11/2轨道,采用修正的表面δ相互作用(MSDI),对¹⁰⁴Cd,¹⁰⁶Cd,¹⁰⁸Cd,¹¹⁰Cd,¹¹²Cd,¹¹⁴Cd和¹¹⁶Cd等7个偶偶核作了形变HF计算.得到了基态和一些激发态的解.同时,还用近似角动量投影形变Hartree-Fock(PDHF)方法对¹⁰⁸Cd和¹¹⁰Cd进行了能谱计算,得到其正、负宇称带的解,计算结果与实验谱基本一致.     

原子核的反常宇称能谱研究

将具有负宇称的 fp 空间扩大到包含1g9/2 轨道, 采用修正的表面相互作用(MSDI), 对64Ge, 66Ge, 68Ge, 70Se, 72Se, 74Se, 76Kr 和 78Kr等偶偶核作了形变Hartree Fock计算, 得到了基态和一些激发态的解. 同时, 还用近似角动量投影形变Hartree Fock（PDHF）方法对偶偶核64Ge, 74Se和奇A核79Kr进行了能谱计算, 得到其正、 负宇称带的解, 计算结果与实验谱基本一致.Using modified surface delta interaction, enlarging the fp configuration space to include the 1g9/2 orbit with the abnormal parity, the deformed Hartree Fock calculations for the eight nuclei: 64Ge, 66Ge, 68Ge, 70Se, 72Se , 74Se, 76Kr and 78Kr are performed. The ground state and some particle hole excited configurations are obtained. The approximate angular momentum projected deformed Hartree Fock (PDHF) method is applied to even even nuclei 64Ge and 74Se and odd A nuclus 79Kr. Both of their normal and abnormal parity bands are obtained. The calculated energy spectra are consistent well with experimental spectra.     

1h11/2轨道对A～100区偶偶核形状影响的系统研究

采用修正的表面δ相互作用(MSDI),对^102—114Ru,^102—116Pd和^104—116Cd等22个偶偶核分别在gds和gdsh两种不同的组态空间中作了形变HF计算.得到了长、扁椭球等基态或激发态的解.结果表明在质量数为102—116间的原子核存在形状过渡和形状共存现象,且单粒子能级随质量数及组态的不同而不同.两种不同组态空间中的计算结果的对比表明,形变HF计算中1h_11/2轨道的介入及填充与否对A～100区偶偶核的单粒子能谱及形状有较大影响     

DHF方法对A～100区偶偶核形状的系统研究

采用修正的表面δ相互作用(MSDI),对^102—114Ru、^102—116Pd和^104—116Cd等22个偶偶核作了形变HF计算.得到了长椭球、扁椭球等基态或激发态的解.结果表明,在质量数为102—116间的原子核存在形状过渡、形状共存现象,且单粒子能级随质量数及组态的不同而不同.同时发现质子数的多少以及3S_1/2轨道的开始填充对形状过渡起着重要作用.     

76Se三声子态成员的候选者

通过⁷⁶Br (T_1/2=16.2h)β⁺/EC衰变方法得到⁷⁶Br衰变纲图, 并确认了Muller等通过核反应⁷⁶Se(p, p′)方法发现⁷⁶Se能级纲图中1791.31keV能级. 不过, Muller等当时并没有指出该条能级的自旋和宇称, 以及应该属于哪一个声子态的成员. 经过分析我们认为1791.31keV能级可以作为⁷⁶Se三声子态的一个候选成员. 此外, 为了研究这个介于强形变和球形核之间的过渡区核的形变, 对它的正宇称态进行了采用推转壳模型形式的总转动能面计算.     

锕系核集体运动的负宇称态

从锕系区40多个核的正负宇称态的实验数据,如激发能、J^π、电偶极跃迁等,得到一系列与核结构有关的物理量,如宇称劈裂能级差δE_I,正负宇称带的第一和第二类转动惯量J⁽¹⁾和J⁽²⁾及第一负宇称态的电偶极跃迁强度比等,以及它们与角动量I或转动角频率ω的动力学和核子数A的系统行为,从而为研究锕系核负宇称态的产生机制及动力学特点提供了信息.     

125Ba高自旋态的测量

通过¹⁰⁹Ag(¹⁹F,3n)核反应布局了¹²⁵Ba核的激发态.使用带BGO康普顿抑制的高纯锗探测器阵列和常规在束γ实验技术,测量了它的高自旋态.建立在h_11/2中子支壳上的负宇称带和建立在g_7/2中子支壳上的正宇称带分别被延伸到了35/2^－和23/2⁺态.负宇称带显示出明显的正负Signature劈裂,而正宇称带则几乎没有这种劈裂.负宇称正负Signature带均出现反弯,其反弯处转动频率与¹²⁴Ba晕带反弯频率相近.正宇称带出开始出现反弯迹象.     

Rn-Th偶偶核的八级形变研究

用推转壳模型在多维形变空间系统研究了Rn-Th偶偶核的基态性质及高自旋情形下的性质, 其中选取的形变自由度为β₂, β₃, β₄和β₅. 计算结果很好的再现了实验提取的转动惯量值. 势能面的研究表明, 随中子数的增加, 基态形状由近球形(N≈130)逐渐演变为八极形变(N≈136)后又发展成为稳定的四极形变(N≥140). 推转计算表明Rn-Th偶偶核的八极形变非常软, 在推转到高自旋情形下, 逐渐变为反射对称形变.     

巨偶极共振相互作用玻色子模型的连续变量表示解

本文应用动力学群表示的生成坐标方法(DGR-GCM)推导并讨论了IBM(s,p,d)的连续变量表示;分析了^148,150Nd和^152,154Sm的静态势能,得到各核的形变参量β₀;求解相应的等效哈密顿量的本征方程,得到了能量本征值和本征函数,并得到了形变核的巨偶极共振劈裂以及纵向的与横向的电偶极强度之比(S₊/S_－)小于2的结论,这与从IBM(s,p,d)的代数分析结果相一致.     

135La高自旋态的实验研究

利用在束γ谱实验技术,通过¹²⁸Te(¹⁰B,3n)¹³⁵La反应研究了¹³⁵La的高自旋态.基于γγ符合关系、γ射线的相对强度和各向异性度的测量结果,建立了¹³⁵La的能级纲图.在hω≈0.40MeV附近,观测到基于πh_11/2质子轨道上的负宇称带的带交叉.比较N=78同中子素链能级结构的系统性,认为该带交叉是由一对h_11/2准质子发生转动顺排造成的.在高自旋态处,观测到具有很强M1跃迁、Signature劈裂很小的ΔI=1负宇称带,根据系统性认为该带是建立在πh_11/2(νh_11/2)²组态上的γ≈–60°的扁椭球形变带.     

偶偶Pd同位素核的HF态及能谱研究

采用修正的表面δ相互作用（ＭＳＤＩ），对１０６Ｐｄ、１０８Ｐｄ、１１０Ｐｄ、１１２Ｐｄ、１１４Ｐｄ和１１６Ｐｄ等６个偶偶核做了形变ＨＦ计算．得到了长椭球、扁椭球和一些激发态的解．结果表明，在质量数为１０６到１１６间的原子核存在形状过渡，且单粒子能级随质量数及组态的不同而不同．同时，还用近似角动量投影形变Ｈａｒｔｒｅｅ－Ｆｏｃｋ（ＰＤＨＦ）方法对１１０Ｐｄ进行了能谱计算，其计算结果与实验谱基本一致，并且发现投影谱具有γ软性核谱的特征． By using modified surface delta interaction, the deformed Hartree Fock calculations are performed for the six nuclei: 106 Pd, 108 Pd, 110 Pd, 112 Pd, 114 Pd and 116 Pd. The prolate, oblate and some particle hole excited configurations are obtained.The calculated results show that there is a form transition from mass number 106 to 116, and that single particle energy spectra are different not only for the nuclei with different mass...     

奇A核101Pd和101Ru的负宇称带能谱研究

将具有正宇称的gds组态空间扩大到包含具有负宇称的1h11/2轨道,采用修正的表面δ相互作用(MSDI)对101Pd和101Ru两个奇A核进行了形变HF计算,得到了基态和一些激发态的解.同时,还用近似角动量投影形变Hartree Fock(PDHF)方法对101Pd和101Ru进行了能谱计算,得到其正、负宇称带的解,计算结果与实验谱基本一致. Using modified delta interaction, enlarging the gds configuration space to include the 1h_11/2 orbital with negative parity, the deformed Hartree Fock calculations for both nuclei: 101Pd and 101Ru are performed. Their ground state and some excited configurations are obtained. The approximate angular momentum projected deform Hartree Fock (PDHF) method is also applied to nuclei 101Pd and 101Ru, and both of their positive and negative parity bands are obtained...     

相对论Hartree-Fock研究奇特核的性质

采用相对论Hartree-Fock(RHF)理论来描述奇特核的性质.为了研究Fock项和矢量介子对奇特核性质的贡献和避免有效相互作用的不惟一性,本文推广应用没有自由参数的密度有关的相对论Hartree(RDH)和Hartree-Fock(RDHF)理论来描述奇特核的性质.在RDH和RDHF近似下,计算了钙同位素链的性质,特别研究了Fock交换项和矢量介子的贡献.研究表明交换项和矢量介子对非常丰中子核的性质,如结合能,中子均方根半径,中子密度分布的影响是非常不同于对稳定线附近核性质的影响.同时,对研究滴线奇特核性质的重要性及其理论模型做了简单的讨论.     

Excitation-energy dependence of Coulomb barriers

The lowering of the Coulomb-barrier for charged particle evaporation from highly excited compound nuclei has been investigated in a folding model. The temperature-dependence of the nuclear densities has been obtained from the Thermal Hartree Fock approximation. It is found that for T?3MeV mesurable shifts of the peak-energies of evaporation spectra should appear.     

Quantum confinement analysis of nanostructures in oxidation of SiGe alloys

We report the investigation on the oxidation behaviour of Si_{1-x}Ge_x alloys (x=0.05, 0.15, and 0.25). It was found for the first time that a nanocap (thickness: 1.6－2.0nm) was formed on the oxide film after fast oxidation. Some new peaks in photoluminescence spectra were discovered, which could be related to the Ge nanocap, the Ge nanolayer (thickness: 0.8－1.2nm) and the Ge nanoparticles (with various diameters from 2.6nm to 7.4nm), respectively. A suitable model and several new calculating formulae combined with the Unrestricted Hartree－Fock－Roothaan (UHFR) method and quantum confinement analysis have been proposed to interpret the PL spectra and the nanostructure mechanism in the oxide and Ge segregation.     

相对论和非相对论理论模型研究奇异核的性质

采用相对论和非相对论理论模型可描述奇异核的性质 .相对论平均场理论预言了2 6,2 7,2 8P存在一个质子晕 ,而27,28,29S存在两个质子晕 .最近 ,MSU的最新的实验发现了2 6,2 7,2 8P核存在一个质子晕.采用相对论 Hartree- Fock理论研究了 Fock项和矢量介子对奇异核性质的贡献,研究表明交换项和矢量介子对非常丰中子核性质的影响非常不同于对稳定线附近核性质的影响.同时,采用形变的Hartree- Fock- Bogoliubov理论研究了某些轻核同位素链的性质和形变.     

He(I) Photoelectron spectroscopy of transient species: fluorothiocyanate (FSCN)

Valence ionisation energies, obtained using He(Iα) photoelectron spectroscopy, of the hitherto unknown and unstable molecule FSCN are presented. Interpretation of the spectra is based on experimental considerations, correspondence with the spectra of related molecules, and the results of Hartree—Fock—Slater calculations using STF basis sets of double-zeta quality. The molecule is shown to exist in the thiocyanate form.     

Signature and parity splitting in the rotational bands and the chiral bands. Double-minimum potential model

The effects of signature and parity splitting in nuclear spectra and the properties of the chiral bands are analyzed basing on a one-dimensional Schrödinger equation with a double-minimum potential. Rotational bands in odd axial and triaxial nuclei, alternating parity bands in even-even nuclei and the chiral bands in odd-odd nuclei are considered. The results obtained are discussed.