中文摘要：

为二种类的 BEC 的联合 Gross-Pitaevskii 方程被解决了在 Thomas 费密近似(TFA ) 下面的经分解。基于分析溶液，二个公式被导出联系粒子数字 N 和 N _{有二种原子的根平均数平方半径的 B} 。仅仅两种原子有的盒子在一个各向同性的陷井的中心的非零分发被考虑。在这种情况中， TFA 被发现了漂亮地工作。因此，二个公式是适用的并且为 N 和 N _B 。

英文摘要：

The coupled Gross Pitaevskii equations for two-species BEC have been solved analytically under the Thomas-Fermi approximation （TFA）. Based on the analytical solution, two formulae are derived to relate the particle numbers NA and NB with the root mean square radii of the two kinds of atoms. Only the case that both kinds of atoms have nonzero distribution at the center of an isotropic trap is considered. In this case the TFA has been found to work nicely. Thus, the two formulae are applicable and are useful for the evaluation of NA and NB.