释义 |
perforation /ˌpəːfəˈreɪʃn /noun1A hole made by boring or piercing: the perforations allow water to enter the well...- The weight of the metal drum is sufficient to keep it at the depth required and the perforations allow the water to pass through the drum.
- The screen has millions of tiny perforations across it to allow sound to escape from speakers placed behind.
- Such mating pairs are joined by a membrane, perforations in which allow exchange of cytoplasmic factors for several hours before any nuclear exchange.
1.1A small hole or row of small holes punched in a sheet of paper, e.g. of postage stamps, so that a part can be torn off easily: memos are produced in a continuous strip divided by perforations so that the forms can be detached...- He compares this to the paper perforations which prevent tearing across a postage stamp.
- The cracks form perpendicularly to the cooling surface (the top of the flow) unless there are elongated vesicles, which act like the perforations in postage stamps, bending the cracks round them.
- Carefully tear along perforations, separating the two ballot papers and the declaration of identity.
1.2 [mass noun] The action or state of perforating or being perforated: there was evidence of intestinal perforation...- Instead of the respiratory improvement, the patient died 15 days later of abdominal sepsis after intestinal perforation.
- A polymicrobial culture raises the suspicion for intestinal perforation or abscess formation.
- The liver, spleen, kidneys, and pancreas all looked normal, and no evidence of intestinal obstruction or perforation was detected.
OriginLate Middle English: from medieval Latin perforatio(n-), from the verb perforare (see perforate). |