Pinhole free film. A surface free from any defects.

无针孔的涂膜，没有表面缺陷的表面。

youdao

If the silane has no polar group, the surface free energy is low.

反之若硅烷中不含有极性基，则处理后玻纤的表面能较低。

youdao

Cleanness: Very tight Molecular structure, surface free of micro pores Moisture proof.

清洁：分子结构十分紧密，表面无细孔。

youdao

They're stuck to a surface that's provided by the environment that's around them, they're not swimming free in solution.

他们黏联在,周围环境的表面上,而不会在溶液中自由运动

耶鲁公开课 - 生物医学工程探索课程节选

Base jumping sees participants launch themselves from a surface and free fall from high altitudes before opening a parachute.

BBC: Mother's grief at base jump death of Gary Harbird

Base jumping sees participants launch themselves from a surface and free fall from predominantly low altitudes before opening a parachute.

BBC: Devon base jumper Gary Harbird dies in Switzerland

He had hoped that Microsoft would save its ad budget and give Surface away for free.

FORBES: Will Microsoft Really Sell Surface for $199?