973 resultados para YB


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利用40Ca+96Ru融合蒸发反应产生了近质子滴线核133Sm,配合氦喷嘴带传输系统采用“质子-γ”符合方法观测了它们的β缓发质子衰变,其中包括半衰期、质子能谱、第二代子核低位态之间的γ跃迁,并估计出衰变到第二代子核不同低位态的分支比.通过统计理论拟合上述实验数据,指认了133Sm的自旋宇称的可能范围.并用Woods-Saxon Strutinsky方法计算了限制组态的133Sm的核势能面,通过对比发现133Sm的自旋宇称可能有两种成分:5/2+和1/2-.这一结果与2001年发表的133Sm(EC+β+)衰变的简单衰变纲图是相容的.此外用同一方法分析了2001年Eur.Phys.J.A12: 1-4中发表的有关149Yb的β缓发质子衰变实验数据,由此指认了149Yb的基态自旋宇称为1/2-.

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利用在束γ谱学技术,通过反应144Sm(16O,3n)研究了157Yb的高自旋态,其中16O束流的能量为90MeV.采用门套BGO(AC)HPGe探测器进行了长时间的γ-γ-t符合测量.基于γ-γ符合关系、γ射线的各向异性度和DCO系数的测量结果,首次建立了157Yb的高自旋能级纲图.围绕157Yb的能级纲图着重讨论了此核的形状共存和Vi13/2能带随着角动量增加的结构演变,另外还比较了N=87同中子素链的Vi13/2转动带结构的系统性.

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利用在束γ谱学方法 ,通过反应1 4 4 Sm( 1 6O ,3n) 1 57Yb研究了1 57Yb的激发态能级结构 .实验中使用的1 6O束流能量为 90MeV .基于实验得到的γ γ符合关系、γ射线的各向异性度和DCO系数 ,建议了1 57Yb的高自旋能级纲图 .1 57Yb的能级纲图主要由两串跃迁性质明显不同的级联能级组成 ,它们分别对应于νi1 3 2 转动带和单粒子激发态 .着重讨论了1 57Yb的形状共存和νi1 3 2 转动带随角动量的结构演化 .

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Sm-133 was produced via fusion evaporation in the reaction Ca-40+Ru-96. Its P-delayed proton decay was studied by means of "p-gamma" coincidence in combination with a He-jet tape transport system, including half-lives, proton energy spectra, gamma-transitions following the proton emissions, and the branching ratios to the low-lying states in the grand-daughter nuclei. The possible spins and parities of 133Sm were extracted by fitting the experimental data with a statistical model calculation. The configuration-constrained nuclear potential energy surfaces of Sm-133 were calculated by using the Woods-Saxon Strutinsky method. Comparing the experimental and calculated results, the spins and parities Of Sm-133 were assigned to be 5/2(+) and 1/2(-), which is reconciled with our published simple (EC+beta(+)) decay scheme Of Sm-113 in 2001. In addition, our experimental data on the beta-delayed proton decay of Yb-149 reported in Eur. Phys. J., 2001, A12: 1-4 was also analyzed by using the same method. The spin and parity of Yb-149 was assigned to be 1/2-.

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The proton-rich isotope Sm-133 was produced via the fusion evaporation reaction Ca-40 + Ru-96. Its beta-delayed proton decay was studied by p-gamma coincidence in combination with a He-jet tape transport system, and half-lives, proton energy spectra, gamma-transitions following the proton emission, as well as beta-delayed proton branching ratios to the low-lying states in the grand-daughter nucleus were determined. Comparing the observed beta-delayed proton branching ratios with statistical model calculations, the best agreement is found assuming that only one level with the spin of 3/2 in Sm-133 decays or two levels with the spins of 1/2 and 5/2 decay with similar half-lives. The configuration-constrained nuclear potential energy surfaces of Sm-133 were calculated using the Woods-Saxon-Strutinsky method, which suggests a 1/2-ground state and a 5/2(+) isomer with an excitation energy of 120 keV. Therefore, the simple(EC+beta(+)) decay scheme of Sm-133 in Eur. Phys. J.A 11,277(2001) has been revised. In addition, our previous experimental data on the beta-delayed proton decay of Yb-149 reported in Eur. Phys. J. A 12,1 ( 2 0 0 1) was also analyzed using the same method. The spin-parity of Yb-149 is suggested to be 1/2(-).

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用蒸发中子反应产生~(157)Tb和~(153)Er,收集活性样品,作x, #gamma# 单谱及符合谱测量,对~(157)Yb和~(153)Er的(EC+#beta#~+)衰变进行了研究,给出了~(157)Yb及~(153)Er的衰变纲图,其中~(157)Yb的衰变纲图包括25条新#gamma#射线,分析~(157)Yb的衰变纲图,~(153)Er的衰变纲图包括15条#gamma#射线,并指定出~(153)Er半衰变期值,该值与文献给出值符合得很好。指定了~(153)Er的衰变纲图中能级状况

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利用142Nd(16O,5n)153Er和147Sm(16O,6n)157Yb反应并藉助与氦喷嘴快速带传输装置和x(γ) γt-符合测量技术首次建立了153Er和157Yb的(EC/β+)衰变能级纲图。 对153Er的(EC/β+)衰变纲图的分析,得到结果有, 1) 辨认了256.7KeV和634.2KeV的二条低位能级分别为d3/2和d5/2的单质子态。因此,153H0的基态 的形状为球形。在同位素链Ho(Z=67)上,随着中子数的增加,奇质量数Ho核的基态核形状由球形过渡到变形发生在中子数86和88之间。 2) 位于1700.1KeV能级为三粒子态,具有[(πh11/2 νh9/2)1+ νf7/2] , , 的结构特征。 经对157Yb的(EC/β+)衰变纲图分析,得到结果有, 1) 发现了建立在157Tm基态上的Kπ= 转动带的带头部分。用可变转动惯量的三轴行变粒子转子模型对157Tm的转动能谱的计算结果表明,157Tm的基态Kπ= 转动带所对应的形变是三轴形变,相应的形变参数为ε2=0.23,ε4=0.01,γ=35°。给出了随着中子数的增加,奇质量数Tm(Z=69)核的基态核形状由球形过渡到非球形发生在中子数86和88之间。 2) 辨认了一条位于激发能为3502KeV的同质异能态,其寿命>40ns。

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研究了微过氧化物酶-11(MP-11)的聚集状态对其与Yb3+相互作用的影响。紫外-可见(UV-Vis)吸收光谱研究结果表明,在纯水溶液中,由于Yb3+与MP-11分子中血红素卟啉环上的2个丙酸基团的羧基氧发生强的键合作用,使血红素卟啉环的非平面性增加,π-π跃迁所需要的能量减少,但电子跃迁几率降低。因此,MP-11吸收光谱中的Soret带红移10nm,吸光度下降35%。