压实颗粒多孔材料中光的各向异性扩散观测
Observation of anisotropic diffusion of light in compacted granular porous materials
摘要：
众所周知，颗粒物质的压实可导致各向异性的力学性质。最近的工作已经证实了孔隙空间各向异性的联系，但压缩，机械性能和材料微观结构之间的关系仍然知之甚少，需要新的诊断工具。通过研究短光脉冲在压实颗粒材料中扩散传输的时间和空间特性，我们发现粉末压实也会引起光的强烈各向异性扩散。调查技术上重要的材料，如微晶纤维素，乳糖和磷酸钙，我们报告增加光学各向异性的压缩力和径向扩散常数高达1.7倍的纵向。这开辟了新的和有吸引力的路线，材料表征和压缩引起的结构各向异性的调查。此外，通过揭示各向同性扩散模型的不足，我们的观察对粉末压块的定量光谱也有重要意义（例如，药物片剂）。
英文摘要：
It is known that compaction of granular matter can lead to anisotropic mechanical properties. Recent work has confirmed the link to pore space anisotropy, but the relation between compression, mechanical properties and material microstructure remains poorly understood and new diagnostic tools are needed. By studying the temporal and spatial characteristics of short optical pulses diffusively transmitted through compacted granular materials, we show that powder compaction can also give rise to strongly anisotropic diffusion of light. Investigating technologically important materials such as microcrystalline cellulose, lactose and calcium phosphate, we report increasing optical anisotropy with compaction force and radial diffusion constants being up to 1.7 times the longitudinal. This open new and attractive routes to material characterization and investigation of compression-induced structural anisotropy. In addition, by revealing inadequacy of isotropic diffusion models, our observations also have important implications for quantitative spectroscopy of powder compacts (e.g., pharmaceutical tablets).
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
