自然侵入水
naturally encroaching water
[光]谱线自蚀
reversal of a spectral line
近自然群落
approaching nature plant community
自然保护模式
the model of natural protection
……国际自然及自然资源保护联盟
International Union for the Conservation of Nature
Billings自然避孕法
Billings Natural Family planning
C^1自然邻近插值
C^1 natural neighbor interpolant
C1自然邻近迦辽金法
C1 natural neighbor Galerkin method