中文摘要：

认识环境核素在不同地域空气中的浓度分布和沉降到地表环境的通量对气溶胶污染物全球扩散模型的建立和验证、沉积过程示踪和沉积计年、流域侵蚀示踪参比,以及生态系统受天然辐照的评价等多个领域都是关键的依据。自2001年以来在贵阳观风山等地逐周连续采样,对近地面空气和降水中^210Pb和7Be浓度的观测结果表明：①因气象条件变化,近地面空气^210Pb和^7Be周浓度具有2～6周变幅不等的短周期波动。^210Pb空气浓度在年内的总趋势呈现出受气温变化的总体影响和降水的短暂调控;而7Be空气浓度出现连续不断的峰—谷交替。②两核素在近地面空气周浓度的低值同步,^210Pb/7Be比率较高（≥0.8）,显示出海洋性贫^210Pb-^7Be气团的入侵影响;它们高的周浓度也同步耦合,比率较低（≤0.7）,显示出高层大气富^7Be气团的输入。③^210Pb和7Be的周降水浓度及水—气分配系数在秋末～春季较高,而春末—秋季明显偏低。周降水浓度随同期空气浓度呈增高趋势,其季节分界分别为0.2Bq/L和1Bq/L;而Kd值随同期空气浓度增大呈降低趋势。^210Pb和7Be的降水沉降主要分布在每年的春夏季;周沉降量随同期降水量呈增大趋势,^7Be增大的斜率约为^210Pb的3倍;当近于零降水时,它们在降水中的初始比率约为2.5。它们出现高或者较高的周降水沉降都伴随当周或邻周空气浓度的急剧下降;降水中^210Pb/7Be比率主要分布在≤0.5,并与空气中^210Pb/7Be比率基本同步,显示出两核素被降水清洗的效率基本相近。④2008年冰冻极端天气过程中,^210Pb-^7Be空气浓度同步低谷并存在气溶胶低浓度与高比活度耦合。⑤观风山7Be周空气浓度显示低纬度、较高海拔地区的预期水平;短周期波动反映强下沉气流和低海拔上升气团影响分别在观风山和瓦里关山的滞后性。

英文摘要：

It＇s essential to measure air concentrations and depositional fluxes of environmental radionuclides in different regions for modeling global contamination transfer and validation,tracing deposition process and dating,referencing watershed erosion trace and assessing natural radiation of ecosystem.This study introduces the research background and methods and explains weekly variations of ^210Pb and 7Be concentrations in surface air and precipitation at Mt.Guanfeng/Guiyang since 2001.The results indicate that ^210Pb and 7Be concentrations in surface air fluctuate periodically at 2-6 week interval because of the meteorological condition changes.The annual trend in 210Pb air concentration is overall influenced by air temperature variation and periodical rainfall.^7Be air concentration varies up and down regualarly.The synchronization of low concentrations for both ^210Pb and ^7Be in surface air and high ratio（^210Pb/^7Be ≥ 0.8）indicate oceanic poor ^210Pb-^7Be air mass invasion.The synchronization of high concentrations of ^210Pb and 7Be in surface air and low ratio（^210Pb/^7Be ≤ 0.7）implies rich 7Be air mass invasion from altostratus atmosphere.Weekly concentrations of ^210Pb and ^7Be in precipitation and the Kd coefficients are high in late Autumn to Spring,and low in late Spring to Autumn.Although ^210Pb and ^7Be concentrations vary seasonally,their weekly concentrations in precipitation increase with that of air concentration.The ^210Pb and ^7Be weekly concentrations for seasonal division is about 0.2 Bq/L and 1 Bq/L,respectively.However,the Kd coefficient decreases when ^210Pb and ^7Be air concentrations increase.Deposition of ^210Pb and ^7Be with precipitation mainly take place in Spring and Summer;The weekly fallout of ^210Pb and ^7Be increases with increasing precipitation;the increase of 7Be is triple of that of ^210Pb and 2.5 when precipitation nears to zero.The weekly-high fallout of 210Pb and 7Be with precipitation corresponds with the dramatic decrease of their air concentrations within or