isopycnic

例句：

1. 1.The isotopes of carbon and nitrogenare used in the production of plastics.
   碳和氮的同位素用于生产塑料。
2. 2. The isotopes of uranium have been studied for their potential usein nuclear energy.
   铀的同位素已被研究，以探索其在核能中的潜在用途。
3. 3. The isotopes of goldand silver are used in jewelry making.
   金和银的同位素被用于珠宝制作。