Abstract：
Living organisms form complex mineralized composite architectures that perform a variety of essential functions. These materials are commonly utilized for load-bearing purposes such as structural stability and mechanical strength in combination with high toughness and deformability, which are well demonstrated in various highly mineralized molluscan shell ultrastructures. Here, the mineral components provide the general stiffness to the composites, and the organic interfaces play a key role in providing these biogenic architectures with mechanical superiority. Although numerous studies employed state-of-the-art methods to measure and/or model and/or simulate the mechanical behavior of molluscan shells, our understanding of their performance is limited. This is partially due to the lack of the most fundamental knowledge of their mechanical characteristics, particularly, the anisotropic elastic properties of the mineral components and of the tissues they form. In fact, elastic constants of biogenic calcium carbonate, one of the most common biominerals in nature, is unknown for any organism. In this work, we employ the ultrasonic pulse-echo method to report the elasticity tensor of two common ultrastructural motifs in molluscan shells: the prismatic and the nacreous architectures made of biogenic calcite and aragonite, respectively. The outcome of this research not only provides information necessary for fundamental understanding of biological materials formation and performance, but also yields textbook knowledge on biogenic calcium carbonate required for future structural/crystallographic, theoretical and computational studies.
摘要：
活生物体形成复杂的矿化复合结构，执行各种基本功能。这些材料通常用于承载目的，例如结构稳定性和机械强度，以及高韧性和可变形性。在各种高度矿化的软体动物壳超微结构中得到了很好的证明。这里,矿物成分为复合材料提供了总体刚度，有机界面在为这些生物结构提供机械优势方面起着关键作用。尽管许多研究采用了最先进的方法来测量和/或模拟和/或模拟软体动物壳的力学行为，我们对他们的表现的理解是有限的。这部分是由于缺乏对其机械特性的最基本知识，特别是,矿物成分和它们形成的组织的各向异性弹性特性。事实上,生物碳酸钙的弹性常数，自然界中最常见的生物矿物之一，对任何有机体来说都是未知的。在这项工作中,我们使用超声脉冲回波方法来报告软体动物壳中两个常见超微结构基序的弹性张量：由生物方解石和文石制成的棱柱形和珍珠形结构，分别。这项研究的结果不仅为基本了解生物材料的形成和性能提供了必要的信息，而且还产生了未来结构/晶体学所需的生物碳酸钙的教科书知识，理论和计算研究。
