188Tl的πh9/2(○×)νi13/2扁椭球转动带的旋称反转研究

利用能量为170MeV的35Cl束流,通过157Gd(35Cl,4n)熔合蒸发反应研究了188Tl的高自旋态能级结构.依据实验结果建立了188Tl基于πh9/2(○×)νi13/2组态的转动带.根据双奇Tl核能级结构的相似性,指定了188Tlπh9/2(○×)νi13/2扁椭球转动带的自旋值.结果表明在188Tl中,πh9/2(○×)νi13/2扁椭球转动带在低自旋区具有旋称反转性质.利用包含了质子-中子剩余相互作用的准粒子-转子模型,定性地解释了πh9/2(○×)νi13/2扁椭球转动带的低自旋区旋称反转现象.     

An implementable proximal point algorithmic framework for nuclear norm minimization

The nuclear norm minimization problem is to find a matrix with the minimum nuclear norm subject to linear and second order cone constraints. Such a problem often arises from the convex relaxation of a rank minimization problem with noisy data, and arises in many fields of engineering and science. In this paper, we study inexact proximal point algorithms in the primal, dual and primal-dual forms for solving the nuclear norm minimization with linear equality and second order cone constraints. We design efficient implementations of these algorithms and present comprehensive convergence results. In particular, we investigate the performance of our proposed algorithms in which the inner sub-problems are approximately solved by the gradient projection method or the accelerated proximal gradient method. Our numerical results for solving randomly generated matrix completion problems and real matrix completion problems show that our algorithms perform favorably in comparison to several recently proposed state-of-the-art algorithms. Interestingly, our proposed algorithms are connected with other algorithms that have been studied in the literature.     

Rotational alignment of the h11/2 band in 157Dy

High-spin states of ¹⁵⁷Dy were investigated using in-beam γ-ray spectroscopy techniques with a ¹⁵⁰Nd(¹²C, 5n) reaction. Three rotational bands with the h _9/2, i _13/2 and h _11/2 configurations were observed up to (43/2^-), 53/2⁺ and 45/2^-, respectively. Interband M1 transitions in the h _11/2 (high-Ω) band were also measured up to the highest-spin state. The high-spin states were well reproduced by calculations using the tilted-axis-cranking model (TAC). The B(M1)/B(E2) ratio, Routhian and the tilted angle of the angular-momentum vector are found to be in good agreement with the result of the TAC calculation. Received: 22 August 2002 / Accepted: 26 September 2002 / Published online: 19 November 2002 RID="a" ID="a"e-mail: hayakawa@jball4.tokai.jaeri.go.jp Communicated by W. Henning     

Structure evolution along the yrast-line in 101pd

High-spin states in 101Pd have been investigated experimentally via the 76Ge(28Si,3nγ)101Pd reaction.The previously known bands based on the d5/2 and h11/2 neutron orbitals have been extended to higher-spin states,and two new structures have been observed.Spin and parity were assigned to the levels on the basis of the experimental results of the angular distribution of γ rays deexciting the oriented states.For the ground-state band,the E-GOS(E-Gamma Over Spin) curve strongly suggests a structure transition from vibration to rotation while increasing spin.     

Ramanujan type identities and congruences for partition pairs

Using elementary methods, we establish several new Ramanujan type identities and congruences for certain pairs of partition functions.     

High-spin states and signature inversion in odd-odd 182Au

High-spin states in 182Au have been produced and studied via the 152Sm(35Cl,5nγ)182Au reaction. The level scheme consisting of the πh9/2(*)Vi13/2 and πi13/2(*)V i13/2 bands has been established for the first time. The low spin signature inversion in both bands has been found. The observed signature inversion phenomena can be interpreted qualitatively using the pairing and deformation self-consistent cranked Wood-Saxon calculations.     

80Rb的旋称劈裂反转及负宇称带的回弯

通过熔合蒸发反应⁶⁵Cu+¹⁹F,⁶⁶Zn+¹⁸O及⁶⁸Zn+¹⁶O,在3种入射束流的能量分别为75MeV,76MeV及80MeV研究了⁸⁰Rb高自旋态的能级结构.增加了20多条新的γ跃迁,在已知负宇称转晕带上建立了两条新的边带.将原有的第二条负宇称带的自旋态从12^－推高到了22^－,并首次观察到这个带的回弯,它的回弯频率为0.49MeV;负宇称转晕带在15^－时出现了旋称反转,第二负宇称带存在明显的旋称劈裂,但没有观察到旋称反转,这两条负宇称带的结构均与其同中子数核⁸²Y非常相似.     

The Influence of the Capping Agent on the Oxidation of Silver Nanoparticles: Nano‐impacts versus Stripping Voltammetry

The influence of capping agents on the oxidation of silver nanoparticles was studied by using the electrochemical techniques of anodic stripping voltammetry and anodic particle coulometry (“nano‐impacts”). Five spherical silver nanoparticles each with a different capping agent (branched polyethylenimine (BPEI), citrate, lipoic acid, polyethylene glycol (PEG) and polyvinylpyrrolidone (PVP)) were used to perform comparative experiments. In all cases, regardless of the capping agent, complete oxidation of the single nanoparticles was seen in anodic particle coulometry. The successful quantitative detection of the silver nanoparticle size displays the potential application of anodic particle coulometry for nanoparticle characterisation. In contrast, for anodic stripping voltammetry using nanoparticles drop casting, it was observed that the capping agent has a very significant effect on the extent of silver oxidation. All five samples gave a low oxidative charge corresponding to partial oxidation. It is concluded that the use of anodic stripping voltammetry to quantify nanoparticles is unreliable, and this is attributed to nanoparticle aggregation.