convergence-and-divergence 收敛性与发散性； 会聚与发散；敛散性
例句：
Convergence and divergence of infinite series dependupon this concept.
无穷级数的收敛性与发散性与此概念有关。
The convergence and divergence nature of thin lens in different media
薄透镜在不同介质中的会聚与发散性质。
Two Methods of Howto Judge Convergence and Divergence of Positive TermSeries
正项级数敛散性的两个判别法。