Rigid polyurethane foam is a polymer thermosetting heat preservation material, heat conduction coefficient 0.024 W / (m?
聚氨酯硬泡是一种高分子热固性保温材料，导热系数0.024 W/（m?。
2
Besides, the relations between variance ratio and correlation coefficient and between W-K statistics and correlation coefficient are found.
此外，找到了方差比，W - K统计量与相关系数之间的精确关系。
3
The coefficient curves of R&D on technical progress show oblique "W" type, but on the whole, the economic benefits generated by R&D will get better and better.