Topic construction, in essence, is a cognitive reference point construction, in which topic is the reference point, and target is a proposition.

话题构式本质上就是一个认知参照点构式，其中话题为参照点，目标为一个命题。

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There are also existed two ways for target point positioning: gray-scale projection and the reference point.

在目标点的定位方面也介绍了两种方式，一个是使用灰度投影，另外一个是使用参考点。

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Results By using ICRU dose reference point (the central point of target) as theunitary dose, 95% dose line could be surrounded above 95% of the PTV.

结果：以ICRU剂量参考点（靶中心点剂量）剂量归一，95%剂量线均能包绕95%以上的PTV。

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