目的：理解在中、重度分级的颈椎间盘退变(DD)过程中，AD和PD高度变化(丢失和增加)如何影响PF连接负荷。

Objective. To understand how height patterns (loss and gain) at AD and PD affects the PF contact loading during moderate and severe grades of cervical disc degeneration (DD).

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挡墙高度比较高时也可采用分级式的挡墙，可以节省工程材料的用量，比较经济，同时比纯重力式的更美观。

Wall height is higher also can use classification type retaining wall, can save the engineering material consumption, more economical, and more beautiful than the pure gravity.

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与机械搅拌式水力分级机比较，高度较小，便于配置。

With mechanical agitation hydraulic classifier comparison, a high degree of small, easy to configure.

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