positivity          
noun [ U ] uk/ˌpɒz.əˈtɪv.ə.ti/ us/ˌpɑː.zəˈtɪv.ə.t̬i/
 正面,积极
the quality of having a positive attitude
  I'm a great believer in positivity. 我认为保持正面积极非常重要。 
 Opposite: negativity
  (测试等)有正面结果
the fact that something such as a test has a positive result
  a 3 per cent positivity rate 3%的正面结果