This primary bone is characterized by immature bone trabeculae which are aligned along the direction of traction exerted by the periodontal fibers. Secondary bone can be identified by its osteon-like ...

同时，建立了从宏观（10-2 m 量级）到微观（10-4 m 量级）的多层有限元模型，聚焦腰椎皮质骨的动力学特性，详细定义了骨单位（osteon，由哈弗斯管、骨板介质和黏合线等组成）的结构和参数1。 设定边界条件与接触设置：在宏观模型中，添加 40kg 质量点模拟人体 ...

Powered flight has evolved separately in three tetrapod clades: pterosaurs, birds (avian dinosaurs), and bats. To meet the challenges of powered flight, tetrapods acquired structural, mechanical, and ...