"The center of the earth is literally a crystal," said Stephenson. Over time, it grew and now is no longer a single crystal but an aggregate of them.

“地球的中心严格意义上是一个晶体，”斯蒂文森说，它逐渐成长，现在已不是一个单晶，而是众多单晶的组合体。

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The individual crystal units comprising the aggregate structure where the crystalline orientation does not change. The grain boundary is where these individual crystal units meet.

构成总的结构的单个的晶体个体，而晶体的方位并没有发生变化。晶界是这些单个的晶体单位相遇的界限。

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IPN gel shows network structure and the aggregate of the network structures is spherical particle, the crystal structure can also be observed obviously.

IPN凝胶呈网状结构，聚合物网络结构的聚集体为圆球状颗粒形式，并可以观察到明显的结晶结构；

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