1. A metal sheet or plate connecting the heavier sections, ribs, or flanges of a structural element.
类似物一个母化合物的结构衍生物，通常只有一个元素不同
2. The prime example is the element uranium (U), which occurs naturally as two isotopes-the lighter, fissionable U-235 and the heavier, non-fissionable U-238.
铀（U）元素就是一个很好的例子。天然铀有两种同位素；较轻的负235可以裂变，较重的铀238则不会裂变。
3. It is the 26th artificial element heavier than uranium to have been added to the periodic table.
它是第26个在元素周期表上由人工合成的超铀重原子。
4. AGB stars have important significance to the element nucleosynthesis and the chemical evolution of the galaxy. They are the main site where elements heavier than Fe are formed in universe.
AGB星对于元素核合成及星系化学演化都有非常重要的意义，它们是宇宙中比Fe更重的元素的重要产生地。