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Investigation of Nuclear Binding Energy and Charge Radius Based on Random Forest Algorithm

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原子能科学技术 2023年第4期57卷 704-712页

作者： CAI Boshuai YU Tianjun LIN Xuan ZHANG Jilong WANG Zhixuan yuan cenxi Sino-French Institute of Nuclear Engineering and Technology Sun Yat-sen UniversityZhuhai 519082China

The random forest algorithm was applied to study the nuclear binding energy and charge *** regularized root-mean-square of error(RMSE)was proposed to avoid overfitting during the training of random *** for nuclides with Z,N>7 is reduced to 0.816 MeV and 0.0200 fm compared with the six-term liquid drop model and a three-term nuclear charge radius formula,*** interest is in the possible(sub)shells among the superheavy region,which is important for searching for new elements and the island of *** significance of shell features estimated by the so-called shapely additive explanation method suggests(Z,N)=(92,142)and(98,156)as possible subshells indicated by the binding *** the present observed data is far from the N=184 shell,which is suggested by mean-field investigations,its shell effect is not predicted based on present *** significance analysis of the nuclear charge radius suggests Z=92 and N=136 as possible *** effect is verified by the shell-corrected nuclear charge radius model.

关键词： nuclear binding energy nuclear charge radius random forest algorithm

What kind of optical model potentials should be used for deuteron stripping reactions?

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Science China(Physics,Mechanics & Astronomy) 2020年第2期63卷 64-70页

作者： XiaoYan Yun DanYang Pang YiPing Xu Zhi Zhang RuiRui Xu ZhongYu Ma cenxi yuan yuan51School of Physics Beihang UniversityBeijing 100191China Beijing Key Laboratory of Advanced Nuclear Materials and Physics Beihang UniversityBeijing 100191China China Nuclear Data Center China Institute of Atomic EnergyBeijing 102413China China Institute of Atomic Energy Beijing 102413China Sino-French Institute of Nuclear Engineering and Technology Sun Yat-Sen UniversityZhuhai 519082China

This paper presents the results of a study that compares CTOM, a microscopic optical model potential(OMP), which is an optical model co-created by the China Nuclear Data Center & Tuebingen University, to CH89, which is a typical phenomenological *** respective OMPs were tested by applying them to the modelling of nucleon elastic scattering and(d,p) transfer reactions involving14C,36S, and58Ni targets at both low and relatively high energies. The results demonstrated that although both potentials successfully accounted for the angular distributions of both the elastic scattering and transfer cross sections, the absolute values of the transfer cross sections calculated using CTOM were approximately 25% larger than those calculated using CH89. This increased transfer cross sections allowed CTOM to produce single particle strength reduction factors for the three reactions that were consistent with those extracted from(e,e′p) reactions as well as with more recent(p,2p) and(p,pn) reactions. Notch tests suggested that nucleon elastic scattering and transfer reactions are sensitive to different regions of the OMP;accordingly,phenomenological OMPs, which are constrained only by elastic scattering cross sections, may not be sufficient for nucleon transfer reactions. Therefore, we suggest that microscopic OMPs, which reflect more theoretical considerations, should be preferred over phenomenological ones in calculations of direct nuclear reactions.

关键词： optical model potentials elastic scattering transfer reactions spectroscopic factors

Charge Dependence of an Inferred Isomer in^(92)Zr

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IMP & HIRFL Annual Report 2022年第1期 33-34页

作者： Jia Chenxu Guo Song yuan cenxi Institute of Modern Physics Chinese Academy of SciencesLanzhou 730000China School of Nuclear Science and Technology University of Chinese Academy of ScienceBeijing 100049China Sino-French Institute of Nuclear Engineering and Technology Sun Yat-Sen UniversityZhuhai 519082GuangdongChina

The inuence of the electronic environment on nuclear decay has been proposed for long time^([1]).The lifetime of some excited states of nucleus may change due to the inuence of electron wave function.A typical example is a 20%reduction in the half-life of an isomer of^(57)Fe a ected by the charge state^([2]).By blocking the internal conversion channels,lifetimes of excited states in highly-charged nuclei can be prolonged.

关键词： function excited lifetime

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轻质量原子核中子发射的衰变宽度理论描述

科学通报 2022年第23期67卷 2782-2789页

作者：蔡博帅袁岑溪中山大学中法核工程与技术学院珠海519082

本文尝试提出描述轻质量原子核中子发射衰变宽度的理论公式.使用Wentzel-Kramers-Brillouin(WKB)近似和R-matrix方法计算了单中子发射的衰变宽度.通过WKB近似和R-matrix方法的隧穿因子,得到描述单中子发射宽度一般规律的三变量公式,使... 详细信息

本文尝试提出描述轻质量原子核中子发射衰变宽度的理论公式.使用Wentzel-Kramers-Brillouin(WKB)近似和R-matrix方法计算了单中子发射的衰变宽度.通过WKB近似和R-matrix方法的隧穿因子,得到描述单中子发射宽度一般规律的三变量公式,使用该公式计算的结果与实验值的均方根误差小于0.6个数量级.研究结果有助于进一步研究中子滴线附近丰中子核的性质.

关键词：单中子发射衰变宽度 WKB近似 R-matrix方法唯象公式

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哪些核适合被液滴模型描述:基于不确定度分解方法的统计研究（英文）

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原子核物理评论 2017年第1期34卷 110-115页

作者：袁岑溪中山大学中法核工程与技术学院广东珠海519082

一个模型适合描述哪些物理量?这个问题可以通过模型的物理来源来回答。比如,液滴模型适合描述重核和远离满壳核。这是因为液滴近似更适用于核子数多的核以及液滴模型不包含壳效应。这样的回答是定性的并需要清楚模型的物理来源。是否可... 详细信息

一个模型适合描述哪些物理量?这个问题可以通过模型的物理来源来回答。比如,液滴模型适合描述重核和远离满壳核。这是因为液滴近似更适用于核子数多的核以及液滴模型不包含壳效应。这样的回答是定性的并需要清楚模型的物理来源。是否可能仅通过模型的数学形式和实验数据就能给出半定量的解答?利用最近提出的不确定度分解方法尝试对液滴模型适合描述哪些核这一问题进行半定量的回答。并且不需已知液滴模型的物理来源,仅需其数学形式以及实验数据。通过不确定度分解方法,液滴模型与实验数据间的残差可以分解为系统不确定度和统计不确定度。两者分别代表了模型的缺陷和模型不精确的参数带来的不确定度。基于这一分解,核素图上的原子核可以按其对应的残差被半定量地划分为系统不确定度主导、统计不确定度主导、以及中间区域。液滴模型适合描述的核就是统计不确定度主导残差的核而不是像通常认为的是残差最小的核。从核素图上看,统计不确定度主导残差的核正是重核以及远离满壳核,与液滴模型物理来源一致,但得到这一结果的过程是半定量的且仅需液滴模型的数学形式以及实验数据。如果对由统计不确定度主导残差的核重新拟合液滴模型的参数,模型可以很好地描述这些核(标准差小于0.7 MeV)。

关键词：原子核不确定度分解方法液滴模型统计不确定度系统不确定度

Fine structure ofαdecay in^(222)Pa

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Chinese Physics C 2021年第4期45卷 192-197页

作者： Wei Hua Zhiyuan Zhang Long Ma Zaiguo Gan Huabin Yang cenxi yuan Minghui Huang Chunli Yang Mingming Zhang Yulin Tian Xiaohong Zhou Sino-French Institute of Nuclear Engineering and Technology Sun Yat-sen UniversityZhuhai 519082China CAS Key Laboratory of High Precision Nuclear Spectroscopy Institute of Modern PhysicsChinese Academy of SciencesLanzhou 730000China School of Nuclear Science and Technology University of Chinese Academy of SciencesBejing 100049China

With the help of the gas-filled recoil spectrometer SHANS and a digital data acquisition system,the fine structure of the α decay for^(222)Pa was *** nuclides were produced through the 1p3n evaporation channel via the heavy-ion induced fusion evaporation reaction ^(40)Ar+^(186)*** on the ER-α1-α2-α3 andα-γcorrelation measurement,three new α decays were observed in addition to the three branches known *** one with the largestαdecay energy was regarded as the ground state to ground state *** newly measuredαdecay properties of ^(222)Pa were examined in a framework of reduced width.

关键词： fusion-evaporation reaction αdecay fine structure Q_(α)reduced width

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轻质量及中质量核结构的壳模型研究

核技术 2014年第10期37卷 12-16页

作者：袁岑溪亓冲中山大学中法核工程与技术学院珠海519082 瑞典皇家工学院瑞典斯德哥尔摩se10691

壳模型被广泛应用于研究轻质量及中质量核的性质,它能很好地描述这些原子核的基态和低激发态的能量、电磁矩和电磁跃迁以及β衰变等性质。本文简要介绍了原子核壳模型的基本框架,如何选择单粒子基矢和构建模型空间和有效哈密顿量。对不... 详细信息

壳模型被广泛应用于研究轻质量及中质量核的性质,它能很好地描述这些原子核的基态和低激发态的能量、电磁矩和电磁跃迁以及β衰变等性质。本文简要介绍了原子核壳模型的基本框架,如何选择单粒子基矢和构建模型空间和有效哈密顿量。对不同区域的原子核的壳模型最新研究做了回顾。在psd区,介绍一个新的相互作用成功地描述碳、氮、氧的中子滴线及其它性质以及A=20附近弱束缚丰质子核的谱学性质;在fp区,介绍了N=Z奇奇核中不同同位旋形成的转动带,以及通过N=Z附近的镜像核研究核力的电荷对称性破缺;在更重的区域,介绍了92Pd这个N=Z的原子核中同位旋标量质子中子对起主导作用,以及Sn同位素的研究。

关键词：原子核壳模型轻质量及中质量核低激发态能谱电磁跃迁质子中子对

Two-nucleon Excitation from p to sd Shell in ^(12,14)C

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原子核物理评论 2016年第2期33卷 246-249页

作者：袁岑溪张敏兰念吾方尤俊 Sino-French Institute of Nuclear Engineering and Technology Sun Yat-Sen University

The effect of the two-nucleon excitation from p to sd shell is discussed on12 C and14C in the frame work of the nuclear shell model. The recently suggested shell-model Hamiltonian YSOX provides an suitable tool to investigate the 2hω excitation in psd region. Because the strength of the interaction, which represents the interaction between the 0 and 2hω configurations, is considered in the construction of the Hamiltonian YSOX. The level of12 C is almost independent on the interaction, but excitation energies of certain states in14 C are strongly affected by *** investigation shows that the percentage of 2hω configuration in these states is quite different from that of the ground state. The non-linear effects of the interaction on the configurations and transition rates are also discussed.

关键词： nuclear shell model psd model space Hamiltonian YSOX 2hω configuration

A=20附近丰中子和丰质子核分离能的壳模型计算

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中国科技论文 2015年第11期10卷 1250-1252,1264页

作者：袁岑溪中山大学中法核工程与技术学院广东珠海519082

使用原子核壳模型,研究A=20附近丰中子和丰质子核的分离能及滴线性质。在丰中子区,采用新的有效哈密顿量YSOX,此哈密顿量考虑了(2-3)核子的激发态,在此基础上研究C、N和O丰中子同位素的单双中子分离能。在丰质子区,通常的有效哈密顿量如... 详细信息

使用原子核壳模型,研究A=20附近丰中子和丰质子核的分离能及滴线性质。在丰中子区,采用新的有效哈密顿量YSOX,此哈密顿量考虑了(2-3)核子的激发态,在此基础上研究C、N和O丰中子同位素的单双中子分离能。在丰质子区,通常的有效哈密顿量如USD系列没有考虑质子位于1s1/2轨道时的弱束缚效应,考虑此弱束缚效应修正哈密顿量,并用其研究18 Ne、19 Na、20 Mg、21 Al和22Si等丰质子核的单双质子分离能。这些修正的哈密顿量对丰中子和丰质子核的分离能及滴线性质的描述比之前的哈密顿量有了显著的改善,正确地描述了已观测到的滴线性质,说明在研究滴线性质时弱束缚效应和多核子激发态的重要性。

关键词：原子核壳模型丰中(质)子核中(质)子滴线中(质)子分离能