这些火山灰中含有锆石等矿物，这些矿物中的某些组分允许进行精确的放射性测年(以确定精确的年代数据)。

The ash contains minerals such as zircon that can be dated precisely from the radioactive decay of some of their components.

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目的：确定气体组分、气溶胶、放射性物质、温度、湿度和微生物6种污染要素在潜艇舱室空气质量评价中所占的权重。

Objective: to define the weights of 6 main influencing factors, i. e. gas components, aerosol, radioactivity, temperature, humidity and microbial pollution in submarine cabin air quality.

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直肠放射性远期并发症发生率治疗组、对照组分别为13.3%和36.7%，放射性膀胱炎的发生率治疗组、对照组分别为10%和33.3%，两组比较差异有统计学意义（P<0.05）。

The rates of long-term radiation reaction of rectum were respectively 13.3 % and 36.7 %, and the rates of radiation bladderitis 10 % and 33.3 %, with significant difference(P< 0.05).

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