微观描述热核裂变寿命（英文）

有关热核裂变的研究与反应堆中的诱发裂变，天体环境中的裂变，以及超重元素的合成等密切相关。热核裂变的研究通常是基于Bohr-Wheeler 的统计裂变理论。而统计模型的研究十分依赖唯像的能级密度和位能面。因此，提出基于微观的有限温度的能量密度泛函理论计算热核的裂变寿命。可以微观自洽地计算出温度相关的裂变位垒高度，曲率，集体质量参数。基于虚自由能法，从低温到高温的裂变寿命可以由一个统一的框架给出。展示了在裂变研究中温度相关裂变位垒的重要性，并讨论了微观描述热核裂变的前景。The studies of thermal fission rates are relevant to novel reactors, astrophysical environments, and survival probabilities of compound superheavy nuclei. This has been conventionally studied by the Bohr-Wheeler statistical model that depends on phenomenological level densities and fission barriers. In this context, we propose to study the thermal fission rates based on microscopic temperature dependent nuclear energy density functional theory. The microscopic temperature dependent fission barrier heights and curvatures, and collective mass parameters can be self-consistently obtained. The fission lifetimes from low to high temperatures can be given by the imaginary free energy method in a consistent framework. Microscopic temperature dependent fission barriers play an essential role in fission studies.     

超重核密度的计算

用Skyrme Hartree Fock模型计算了超重核的密度分布，并讨论了其形状和同位旋相关性。 以292120核为例，计算表明形变对密度分布有相当大的影响。     

超重核的基态性质

用Skyrme Hartree Fock+BCS方法计算了超重核的基态性质,讨论了结合能、α衰变、形变、壳结构和自发裂变等问题.计算得到的结合能较好地反映了实验测量值,α衰变能与实验值符合很好.发现基本上有两种类型的超重核形变:在270108核附近的β2≈0.2的长椭球形变和在298114核附近的近球形形变.单粒子能级分布计算表明:在质子Z=108和中子N=162存在变形壳,在质子Z=114和中子N=184存在球形壳.用得到的α衰变能和Viola Seaborg公式估算了α衰变半寿命,能合理地符合实验测量值. The ground state properties of superheavy nuclei are investigated using the Skyrme Hartree Fock model. The pairing correlation is treated by the BCS method with the pairing δ force. Binding energies, α decays, spontaneous fissions, shell structures and deformations are discussed. Our calculations reproduce experimential binding energies and α decay energies.It is found that superheavy nuclei can be grouped with two kinds of deformations: i) well deformed prolate shapes (β2≈0.2) around 270108...     

核科学百年讲座第七讲核科学技术在材料科学中的应用

核科学技术和材料科学的结合产生了一门新兴的交叉学科——核材料(也称核固体)，主要指核技术在材料分析、物质改性和新材料研制合成中的应用．文章介绍核技术在材料科学中的应用历史、现状及其前景，包括基本物理原理．     

基于Bayesian神经网络评价核裂变产额分布

核裂变碎片的产额是核能和核应用领域中的关键基础数据。在实验和理论上，获得精确且完整的能量依赖的裂变产额到目前为止都是一个挑战。贝叶斯神经网络(Bayesian Neural Networks，BNN)可以描述需要量化不确定性的逆向回归问题。基于BNN学习已有的裂变产额，可以给出未知的裂变产额及其不确定度。特别是当裂变产物产额的实验数据不完整时，BNN可以推断出完整的裂变产额。在裂变产额的质量分布和能量依赖关系上，BNN的评价结果比较合理。研究结果表明BNN在核数据评价领域有广泛的应用前景。     

奇特核结构与激发的微观研究

原子核是一个从少体到多体过渡的量子体系，展现了很多有趣的集体现象。随着国际上若干大型放射性核束流实验装置的发展，极不稳定奇特核的结构与激发的研究成为当前核物理的前沿热点问题。本工作以形变弱束缚核40Mg为例，基于格点空间连续谱能量密度泛函和自洽的FAM-QRPA对奇特核的基态与激发态跃迁进行了研究。发现弥散的表面密度分布与连续谱对低能共振有很大影响。通过对同位旋矢量偶极激发的研究，说明低能矮共振与巨共振的微观机制有很大差异。此外还进行了大规模拟合，发展针对丰中子核，超重核的新的高精度有效相互作用，以期为相关学科如核天体物理、核裂变能等提供更为可靠的核理论模型。Nuclei are quantum systems in the evolution from few-body to many-body systems, and can exhibit many amazing collective phenomena. With the development of several advanced radioactive-beam facilities, the study of structures and excitations of extreme unstable exotic nuclei has become a hot issue. In this work, we solve the self-consistent FAM-QRPA in large deformed coordinate-spaces to treat continuum effects. We study properties of structures and collective excitations in deformed drip-line nuclei. We found that in weakly bound nuclei 40Mg, the diffuse surface density and pairing density play an important role in low-lying resonance. Through analysis of deformation-induced K-splitting in isovector dipole modes, we see that pygmy resonances have very different mechanism compared to giant resonances. In addition, large-scale fittings are performed to develop highprecision effective interactions, which will provide more reliable theoretical model for related subjects, such as nuclear astrophysics and nuclear fission energy.     

Skyrme-Hartree-Fock计算11Be的晕结构

用形变的Skyrme-Hartree-Fock计算讨论了¹¹Be的晕结构. 通过引入绝热堵塞计算, 得到了¹¹Be的1/2⁺态有很大的形变, 得到的密度分布和实验值很好地符合. 还讨论了出现形变晕态的波函数密度分布和角动量大小等问题.     

Fission Properties of Neutron-Rich Nuclei around the End Point of r-Process

We studied the fission properties of neutron-rich nuclei ^278,286Cf around the end point of r-process by microscopic self-consistent approaches. The fission barriers and potential energy surfaces are obtained by constrained static Skyrme Hartree–Fock-BCS calculations. Fission fragments are studied by dynamical time-dependent Hartree–Fock+BCS calculations. Results show that ²⁸⁶Cf has an octupole deformation at ground state, which can increase the fission barrier height by 1.1...