Becke line thin band or halo of refracted light seen under a microscope at the meeting point of two substances that have different refractive indices.

在偏光显微镜下看到的在两种不同折射率物质的交界处出现的细线或光环。

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Many of the disagreements from that meeting are still unresolved - although anti-globalisation protesters are likely to be thin on the ground.

BBC: Key trade talks in the balance