vivacity       
noun [ U ] uk/vɪˈvæs.ə.ti/ us/vɪˈvæs.ə.t̬i/
 活泼|充满活力
the quality of being vivacious (= attractively energetic and enthusiastic)
  This biography captures the charm and vivacity of an unusual woman. 这部人物传记捕捉到了这位不寻常的的女人的魅力和活力。 
 He had a natural cheerfulness and vivacity that made him an exceedingly pleasant companion.  他天生阳光开朗,活力四射,与他相处身心愉悦。 
 See: vivacious
 - More examples
 - Her vivacity and wit led to her being much in demand as an after-dinner speaker.
 - I love the symphony for its sheer vivacity.
 - The book lacks vivacity and passion.