【摘要】 相对富铀的花岗岩广泛存在于地表和地下人居环境，其析出的氡会对人体健康造成辐射危害，深入研究花岗岩氡析出机理可为氡防护提供理论依据。本文基于分形和混沌理论，对采自湖南衡阳衡山岩体和广西灌阳都庞岭岩体的样品开展花岗岩氡析出通量随时间变化的规律研究，计算了氡浓度时间序列数据的最大Lyapunov指数和混沌吸引子关联维数，并综合分析讨论了环境因素不变条件下花岗岩氡析出的主要影响因素。结果表明，来自衡山岩体和都庞岭岩体的两个样品264组氡浓度时间序列数据的最大Lyapunov指数分别为0.077和0.308,都大于0,证实来自两个不同岩体的花岗岩氡析出随时间的演化过程为复杂的混沌动力学过程，二者的混沌吸引子的分形维数分别为4.714和5.675,反映前者的岩石特征的复杂性要小于后者。控制或描述环境因素不变条件下花岗岩氡析出演化过程的独立变量至少需7个，一方面包括岩石铀含量、镭活度等化学组成，含铀矿物及造岩矿物组成以及铀镭在这些矿物中的赋存形式等原生岩石特征；另一方面是岩石风化和蚀变过程可改变矿物粒度分布、岩石孔隙度、孔径分布、微裂隙的发育程度以及间隙的粗糙度等岩石结构特征。更多还原

【Abstract】 Relatively uranium rich granite widely exists in the surface and underground residential environment. The radon exhalation from granite will cause radiation harm to human health. An in-depth study on the radon exhalation mechanism from granite can provide a theoretical basis for radon protection. Based on fractals and chaos theory, the variation of radon exhalation flux from granite with time is studied for the samples collected from Hengshan rock mass in Hengyang city, Hunan province and Dupangling rock mass in Guanyang, Guangxi province. The maximum Lyapunov exponent and chaotic attractor correlation dimension of radon concentration time series data are calculated and the main influencing factors of radon exhalation from granite under the condition of unchanged environmental factors are comprehensively discussed. The results show that the maximum Lyapunov exponents of 264 sets data of two samples from Hengshan rock mass and Dupangling rock mass are 0.077 and 0.308 respectively. Both results are greater than 0 and which can confirm that the evolution process of radon exhalation from granite with time is a complex chaotic dynamic process. The fractal dimensions of chaotic attractors of two rocks mass are 4.714 and 5.675 respectively. The complexity of reflecting the rock characteristics of the former is less than that of later. At least 7 independent variables are needed to control or describe the radon exhalation from granite under the condition of constant environmental factors. These independent variables include the chemical composition of rock such as uranium content and radium activity, the mineral composition such as uranium bearing minerals and rock forming minerals, and the occurrence form of uranium and radium in these minerals. On the other hand, these independent variables also include the rock structure characteristics that may be changed in the process of rock weathering and alteration such as mineral particle size distribution, rock porosity, pore size distribution, development degree of micro fractures and gap roughness.更多还原