n.朝生暮死；短命；無常的事物

I chose the paper for the ephemerality and the fragility of it. 考慮的理由是它的脆弱性和短暫性；

All of which points out two opposing forces constantly at work on our language: ephemerality and durability. 上述事實(shí)說明了不斷作用于人類語言的兩種對(duì)立的因素：短暫性與持久性。

Inactivated Vaccine using French Adjuvant against Bovine Ephemer al Fever 牛流行熱病毒法國(guó)佐劑滅活疫苗的研制

ephemer 短生植物