缺中子核素125,127,129Ce的转动结构

用组态相关推转Nilsson-Strutinsky方法研究了缺中子核素^125,127,129Ce的转动结构性质, 讨论了转晕带的旋称劈裂和核的形状. 转晕带相应的核形状均是近轴对称的. ^127,129Ce在同一个组态中可能有形状共存. 理论指出即使对于无三轴形变核也有可能出现较大的旋称劈裂.     

Description of all observed rotational bands in ~(128)Pr

The configuration-dependent cranked Nilsson-Strutinsky approach was used to investigate the rotational structures in ¹²⁸Pr and signature splittings of some observed bands could be well described quantitatively at high spin. Its modified model was used to calculate special configurations in order to distinguish the N=4 d_3/2s_1/2 and g_7/2d_5/2 orbitals. All observed bands were compared with the calculated configuration assigned to the band and the agreement between experiment and theory is remarkable.     

A=40核区超形变转动带终止

用组态相关推转Nilsson-Strutinsky模型研究了³⁸K, ³⁶Ar, ^32,34S和³⁵Cl的超形变转动带结构性质. 对一些特殊的近转晕线组态的性质做了较为详细的探讨并预言了其带终止态的自旋值, 尤其是预言了³⁸K有利于实验测量到超形变带终止态的自旋值为19h, 而其四极形变值达ε₂～0.50. ³⁶Ar的理论计算与实验结果较好的一致表明这些预言结果是较可靠的.     

基于IA参数寻优组合核的SVM文本分类研究

支持向量机在解决非线性及高维模式识别中表现出许多特有的优势,被广泛应用在文本分类领域。但是其核函数及其参数的选择对分类效果具有很大的影响,单一核函数难以很好地解决文本分类问题。因此,本文选取了三个常用的核函数进行两两组合,利用加权组合核的形式来弥补单核自身特点可能带来的缺点,然后利用人工免疫算法(Immune algorithm,IA)对组合核进行参数寻优,以提高文本分类效果。实验分析证明,此方法有效。     

Ultrahigh Spin Structures in 157,158,159Er

Rotational structures at ultrahigh spin in ^157,158,159 Er have been investigated with the configuration-dependent cranked Nilsson-Strutinsky approach. Configurations of observed bands are assigned and the corresponding deformations are given theoretically. The calculations suggest that one of ultrahigh spin bands in ^158 Er is triaxial highly deformed and the other is normal-deformed, while both ultrahigh spin bands in ^157Er are suggested to be triaxial highly deformed. The possible ultrahigh spin bands in ^159Er are predicted to be triaxial highly deformed and have shape coexistence in the same configuration. The configurations with two neutron holes in the Nose = 4 orbitals and two neutron holes in the h11/2 orbitals in ^159Er are favoured for ultrahigh spin states but unfavoured for band termination, which is similar to ultrahigh spin bands in ^157,15SEr.     

Ni离子辐照国产ZIRLO合金的辐照性能研究

国产ZIRLO合金是CAP1400重要的燃料包壳管候选材料之一,因此需要在使用前对该材料进行辐照性能考验。研究了国产ZIRLO合金的辐照性能随辐照温度和损伤剂量的变化。辐照实验在中国原子能科学研究院HI-13串列加速器上,采用80 MeV的Ni离子进行,辐照产生的损伤采用透射电子显微镜、能量色散谱和纳米压痕法等方法表征。国产ZIRLO合金在300℃经10 dpa损伤剂量辐照后观察到均匀分布的析出颗粒,同样剂量在700℃辐照析出颗粒数目减少,析出相的主要成分为Nb。辐照后出现硬化现象,辐照损伤剂量越大,硬化程度越高;随着辐照温度升高,辐照硬化呈减小趋势。The domestic ZIRLO is a promising candidate of cladding materials for CAP1400. It is necessary to test its radiation properties before its use. In this paper, the radiation properties of the domestic ZIRLO have been studied as functions of irradiation temperature and dose respectively. The experiment was performed at the HI-13 tandem accelerator of China Institute of Atomic Energy by using 80 MeV Ni ions at different temperature and different dose. The transmission electron microscopy, electron dispersive spectroscopy and nano-indentation were used to characterize the radiation damage. The experimental results show that the precipitates are uniformly distributed at 10 dpa and 300℃, while at 700℃ the number of precipitates is reduced. Among all the precipitates, Nbisthe dominant element. Hardening phenomenon was also observed after irradiation, the higher the radiation dose, the higher the degree of hardening, and it illustrates a decreasing tendency with the increasing of the irradiation temperature.