搜索结果: 1-6 共查到“理学 226Ra”相关记录6条 . 查询时间(0.057 秒)
Spatial variations of 226Ra, 228Ra, and 228Th activities in seawater from the eastern East China Sea
radium isotopes thorium isotopes East China Sea shelf currents seasonal variation water mixing scavenging
2017/4/11
A total of 74 surface and subsurface water samples at depths shallower than 200 m were collected in the eastern East
China Sea (ECS), and spatial and seasonal variations in 226Ra, 228Ra, and 228Th ac...
Radium depletion and 210Pb/226Ra disequilibrium of Marítaro hydrothermal deposits, Los Azufres geothermal field, Mexico
hydrothermal deposits 210Pb 226Ra radium adsorption Los Azufres
2017/4/11
In order to calculate the chronology of hydrothermal deposits precipitated from hot springs at Marítaro, Los Azufres
geothermal field, Mexico, their 224Ra, 226Ra, 228Ra and 210Pb activities were meas...
Assessment of the average effective dose from the analysis of 226Ra, 232Th and 40K in soil samples from Punjab, India
gamma ray spectrometry HPGe detector
2017/4/12
The activity concentrations of the natural radionuclides, namely 238Ra, 232Th and 40K, are measured for soil samples
collected from some locations of the Malwa region of Punjab. An HPGe detector, bas...
北冰洋、白令海226Ra的分布及其水文学意义
北冰洋 白令海 226Ra 分布
2009/5/18
中国首次北极科学考察期间(1999年7～9月), 于北冰洋、白令海分别采集了13份和20份大体积水样, 用于226Ra的分析. 结果表明, 北冰洋、白令海表层海水中226Ra含量分别介于0.28～1.56和0.25～1.26 Bq/m3之间, 平均含量分别为0.76和0.71 Bq/m3, 明显低于其他中低纬度开阔大洋表层水的数值, 说明部分研究海域受海冰融化水的影响. 白令海表层水226Ra的空...
高分辨电感耦合等离子体质谱法测定铀矿石样品中234U/238U、230Th/232Th和228Ra/226Ra同位素比值
234U/238U 230Th/232Th 228Ra/226Ra 铀矿石 高分辨电感耦合等离子体质谱法
2014/6/16
采用氢氟酸-硝酸-盐酸混合酸密闭消解含铀矿石样品，用阴离子交换树脂、阳离子交换树脂和锶特效树脂逐级分离富集铀、钍和镭。使用高分辨电感耦合等离子体质谱(HR-ICPMS)测定分离纯化液中234U/238U、230Th/232Th和228Ra/226Ra同位素。比值的测量精密度取决于比值的大小和对应核素浓度的大小。对质量浓度为10 ng/mL 天然铀测量液，234U/238U的测量精密度优于1.2%；...
岩溶山区表土中7Be、137Cs、226Ra和228Ra地球化学相分配的实验研究表明,4种核素绝大部分(85%以上)存在于Fe Mn氧化物、有机质及残渣相中。它们在表土的迁移过程中具微粒迁移性,能较好地随土粒般运,可作为土粒侵蚀或沉积的示踪剂。但其微粒示踪类型又各具特征：7Be的化学形态与其季节性微粒迁移示踪一致；137Cs的化学形态适用于示踪土粒累计性迁移和沉积计年；226Ra和228Ra存在于...