在有限弹性变形中，边界力的方向与密度将随弹性体的变形而发生显著变化。
In finite elastic deformation, the direction and the density of the boundary force can greatly change with the deformation of the elastic body.
亚急性骨髓炎，最常见病变是伴有薄的硬化边界骨的密度减低区，常常跨过骺板(图1)。
In cases of subacute osteomyelitis, the lesions are most commonly lytic, have a thin sclerotic rim, and often cross the physis (Figure1).
结果胸腺增生（ 1例）表现为胸腺区三角形软组织密度影，边界清楚；
Results Thymic hyperplasia (1 case) appeared as soft tissue density with a triangle shape margin in the region of thymus.
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