不稳定原子核的弱相互作用过程是原子核物理中的重要核过程之一，物理学中宇称不守恒现象就是通过极化60Co原子核的贝塔衰变首先证实的。贝塔衰变是不稳定原子核最常见的衰变模式，一些原子核还有双贝塔衰变现象，最近实验上还在寻找无中微子双贝塔衰变等不稳定原子核的其它弱作用衰变模式。本项目计划发展基于真实核子-核子相互作用的形变准粒子无规位相近似（QRPA）模型，统一自洽地描述一些不稳定核容许贝塔跃迁和第一禁戒贝塔跃迁，计算一些不稳定核贝塔衰变和双贝塔衰变性质，深入分析已有实验数据和理论计算结果的差异，提取新的重要的物理因素，进一步发展计算核贝塔衰变寿命和双贝塔衰变寿命的理论模型，可靠预言一些不稳定核的贝塔衰变和双贝塔衰变寿命等。研究重点放在同位旋自由度对原子核贝塔衰变和双beta衰变性质的影响，用理论模型统一研究原子核贝塔衰变和双贝塔衰变性质，寻找原子核的弱相互作用过程中可能的新规律。

The process of weak interactions for unstable nuclei is one of the important processes in nuclear physics. For example, the violation of parity symmetry is first confirmed by the experiment of beta decay of the polarized 60Co nucleus. Beta decay is a common decay mode for many nuclei. There are also double beta decays with neutrinos for some nuclei. To search for the double decay without neutrinos is a hot point in nuclear physics in recent years. This project is devoted to the development of nuclear-decay models based on the deformed quasi-particle random phase approximation (QRPA) with the realistic nucleon-nucleon interactions. A consistent description of both the allowed beta decay and the first forbidden beta decay is pursued. The beta and double beta decays of some unstable nuclei are studied theoretically. New important physical factors are extracted by analysis of the differences between the exisiting experimental data and the theoretical results. The theoretical models of the beta and double beta decays are developed further to make reliable predictions for the half-lives of the beta and double beta decays of some unstable nuclei. This project will study the impacts of isospin degrees of freedom on the beta and double beta decays of unstable nuclei, develop unified models to study the beta and double beta decays of unstable nuclei, and look for new rules for the nuclear decays with weak interactions.