~(157)Yb的形状共存研究(英文)

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 .

beta-delayed proton decays of Sm-133 and Yb-149

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-.

beta-delayed proton decays and spin assignments for Sm-133 and Yb-149

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(-).

~(153)Er, ~(157)Yb(EC+#beta#~+)衰变纲图的首次建立

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

缺中子同位素~(153)Er和~(157)Yb的（EC/β~+）衰变纲图

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。

微过氧化物酶-11的聚集状态对其与Yb~(3+)相互作用的影响

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%。

Novel Near-Infrared Luminescent Hybrid Materials Covalently Linking with Lanthanide [Nd(III), Er(III), Yb(III), and Sm(III)] Complexes via a Primary beta-Diketone Ligand: Synthesis and Photophysical Studies

A series of novel, colorless, and transparent sot-gel derived hybrid materials Ln-DBM-Si covalently grafted with Ln(DBM-OH)(3)center dot 2H(2)O (where DBM-OH = o-hydroxydibenzoylmethane, Ln = Nd, Er, Yb, and Sin) were prepared through the primary beta-diketone ligand DBM-OH. The structures and optical properties of Ln-DBM-Si were studied in detail. The investigation results revealed that the lanthanide complexes were successfully in situ grafted into the corresponding hybrids Ln-DBM-Si. Upon excitation at the maximum absorption of ligands, the resultant materials displayed excellent near-infrared luminescence.

Near-infrared luminescent xerogel materials covalently bonded with ternary lanthanide [Er(III), Nd(III), Yb(III), Sm(III)] complexes

A beta-diketone ligand 4,4,5,5,5-pentafluoro-1-(2-naphthyl)-1,3-butanedione (Hpfnp), which contains a pentafluoroalkyl chain, was synthesized as the main sensitizer for synthesizing new near-infrared (NIR) luminescent Ln(pfnp)(3)phen (phen = 1,10-phenanthroline) (Ln = Er, Nd, Yb, Sm) complexes. At the same time, a series of lanthanide complexes covalently bonded to xerogels by the ligand 5-(N,N-bis-3-(triethoxysilyl)propyl)ureyl-1,10-phenanthroline (phen-Si) were synthesized in situ via a sol-gel process. [The obtained materials are denoted as xerogel-bonded Ln complexes (Ln = Er, Nd, Yb, Sm).] The single crystal structures of the Ln(pfnp) 3phen complexes were determined.

Highly uniform and monodisperse beta-NaYF4 : Ln(3+) (Ln = Eu, Tb, Yb/Er, and Yb/Tm) hexagonal microprism crystals: Hydrothermal synthesis and luminescent properties

beta-NaYF4:Ln(3+) (Ln = Eu, Tb, Yb/Er, and Yb/Tm) hexagonal microprisms with remarkably uniform morphology and size have been synthesized via a facile hydrothermal route. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), and photoluminescence (PL) spectra as well as kinetic decays were used to characterize the samples. It is found that sodium citrate as a shape modifier introduced into the reaction system plays a critical role in the shape evolution of the final products. Furthermore, the shape and size of the products can be further manipulated by adjusting the molar ratio of citrate/RE3+ (RE represents the total amount of Y3+ and the doped rare earth elements such as Eu3+, Tb3+, Yb3+/Er3+, or Yb3+/Tm3+). Under the excitation of 397 nm ultraviolet light, NaYF4:xEu(3+) (x = 1.5, 5%) shows the emission lines of Eu3+ corresponding to D-5(0-3) -> F-7(J) (J = 0-4) transitions from 400 to 700 nm (whole visible spectral region) with different intensity, resulting in yellow and red down-conversion (DC) light emissions, respectively.