984 resultados para 2P-36
Resumo:
Two-electron-one-photon (TEOP) M1 and E2 transition energies, line strengths and transition probabilities between the states of the 2p(3) and 2s(2)2p odd configurations for B-like ions with 18 <= Z <= 92 have been calculated using the GRASP2K package based on the multiconfiguration Dirac-Hartree-Fock (MCDHF) method. Employing active-space techniques to expand the configuration list, we have systematically considered the valence, core-valence and core-core electron correlation effects. Breit interaction and quantum electrodynamical (QED) effects were also included to correct atomic state wavefunctions and the corresponding energies. Influences of electron correlation, Breit interaction and QED effects on transition energies and line strengths of the TEOP M1 and E2 transitions were analysed in detail. The present results were also compared with other theoretical and experimental values.
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Fragment yields for Z >= 5 from projectile fragmentation using primary beams of Ar-36,Ar-40 at 50 MeV/nucleon on Ni-64 target have been measured in RIBLL fragment separator. We compare the fragment cross sections with the predictions of the empirical EPAX parametrization of fragmentation cross-sections and Statistical Abration-Ablation model (SAA) by considering the RIBLL separator transmission rate. Isotope yield ratios between these two reactions were calculated and isoscaling parameters alpha and beta are extracted, their dependences on fragment atomic number Z and neutron number N were presented.
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利用能量为220MeV左右的~(36)Ar重离子束轰击~(96)Ru和~(106)Cd浓缩同位素靶,通过Al降能片,使能量分布在161-176MeV之间,经过融合蒸发2p反应产生了缺中子同位素~(130)Nd, 经过融合蒸发pn反应生成~(140)Tb。藉助氦喷嘴带传输系统,用X-γ和γ-γ符合方法,分离鉴别了这两种核素,并进一步测定了它们的衰变性质。测定了~(130)Nd的半衰期为13 ± 3s,首次建议了它的EC/β~+衰变纲图,推测了其子核~(130)Pr的基态和低位能级的自旋宇称。修订了(140)Tb的原有极简单的EC/β~+衰变纲图,指认了~(140)Tb的基态自旋宇称为7~+。
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针对①中能反应中同位旋自由度是否达到平衡,②同位旋自由度对几中不同方法测量的核温度是否有影响 这两个基本问题,设计了用30和35MeV/u ~(36,40)Ar轰击~(112,124)Sn反应的实验方案。得到如下结果:对于前角5°处的耗散弹核碎裂产物,丰中子同位素与稳定核的产额比随产物出射动能的增加而减小,而丰质子子同位素与稳定核的产额比随动能的增加而增加,呈现明显的剪刀差分布特性。随耗散时间的增大,产物的平均中质比逐渐由弹核的平均中质比向系统的平均中质比过渡。这个结果说明在该反应中,同位旋自由度没有达到完全平衡。而对于20°处的DIC产物,上述剪刀差分布特性变得更不明显,这是同位旋自由度由非平衡向平衡过渡的表现。后角轻粒子的能谱分析表明,初始热核的同位旋会影响斜率核温度的提取,由于丰中子轻粒子~6He在~(40)Ar + ~(112)Sn系统中的蒸发被抑制,相比~(40)Ar + ~(112)Sn而言,其蒸发比较容易发生在衰变链早期,因此提取的温度偏高,同样,丰质子轻粒子~3He的温度在~(40)Ar + ~(112)Sn中略高。但中后角的同位素产额分析表明,反应系统的同位旋对双同位素比核温度几乎没有影响。核温度作为热核的热力学量,是独立于测量方法的,这种不同的方法得出的差异主要来源于同位旋对衰变机制的影响。作为一个尝试,将中高能反应中的熵的提取推广到这个能区,发现两个系统的熵几乎一致。在量子统计模型框架下,考察核温度与熵的关系发现,~(40)Ar + ~(112)Sn反应的挤出时刻密度略高于~(40)Ar + ~(112)Sn。
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本文描述了一个能在中解(10-100Mev/u)重离子核反应测量中鉴别轻粒子,测量粒子多重性,并能给出轻粒子能量和位置信息的大立体角(θ: 5°-20°φ: 0°-360°)的36单元塑料闪烁体陈列探测器的制作与调试,初步调试结果表明该探测器对轻粒子(p、α等)有较好的分辨。同时对国际上几种规模较大的先进的多单元大立体角粒子探测系统作了比较全面的介绍
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Ultrathin multilayer films of the wheel-shaped molybdenum polyoxometalate cluster (Mo-36)(n) and poly(allylamine hydrochloride) (PAH) have been prepared by the layer-by-layer (LbL) self-assembly method. The ((Mo-36)(n)/PAH)(m) multilayer films have been characterized by Xray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM). UV-VIS measurements reveal regular film growth with each (Mo-36)(n) adsorption. The electrochemical behavior of the film at room temperature was investigated.
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beta, beta-1, 3-Piopylenedithio-alpha, beta-unsaturated arylketones 2 via chemoselective 1,2-addition with allyl or benzyl Grignard reagents afforded the corresponding carbinols 3 and 4. Catalysed by silica gel, the carbinols 3 and 4 were converted to the beta,gamma-unsaturated arylketones 5, 6. The mechanism and reaction condition were discussed.
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Practice Links is a free e-publication for practitioners working in Irish social services, voluntary and nongovernmental sectors. Practice Links was created to enable practitioners to keep up-to-date with new publications, electronic resources and conference opportunities. Issue 36 features articles on equine assisted personal development, the National Child Care Information System and a report on Fieldwork Training for Social Workers
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