宇宙基本常数，比如电磁力强度之类的精细结构常数，符号位“ alpha ”，它们因为被假定为不变量而得名。

Fundamental constants such as the strength of the electromagnetic force - the so-called fine-structure constant, or alpha - get their name from the fact that they are supposedly the same everywhere.

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但理论研究表明，只有特定的几何约束结构，才具有射影不变量。

However, researches show that only some special geometric constrained structures possess projective invariants.

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该标架系统可建立两条同源曲线几何不变量之间的解析关系，用于变形过程几何结构改变的分析。

The frame with its formula can set up analytic relationships among the geometric invariants of two homologous curves, and can be used to analyze the deformation process of geometric structures.

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The loop invariant what does the loop invariant mean? It says, here is a property that is true of this structure every time through the loop.

循环不变量是什么意思？,它是一个在结构体中,每次循环都为真的属性。

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