| 释义 |
uranium 238n.（名词）- The most common isotope of uranium, having mass number 238 and half-life 4.51 × 109 years, nonfissionable but irradiated with neutrons to produce fissionable plutonium 239. 铀238：铀的最普通的同位素，质量数238，半衰期为4.51×109年，不发生裂变但能用中子照亮以产生裂变钸239
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