针对塔黄在喜马拉雅高寒环境中的生存适应机制,本文通过时域有限差分光学模拟,研究了其半透明苞叶表面密集球形突起结构的体温调节作用。温室效应作为一种维持适宜体温的有效策略,通常需要较高的太阳短波辐射透射率。相较于普通莲座叶,塔黄苞叶表面显示出更强的太阳辐射透射能力。模拟分析表明,表面突起结构可增强其在可见光至近红外波段的透射率,从而在强日照条件下更高效地将太阳辐射导入内部温室空间,促进温室效应的形成。进一步研究发现,苞叶表面的分级微观结构通过形成渐变折射率层,避免了折射率的突变,显著抑制了光反射,从而提升了透射效率。这种透射能力的增强使得塔黄能够在有限苞叶体积下,有效地将环境辐射热传导至温室内部,为辐射保温相关的仿生材料与系统设计提供了新的思路。
Regarding the survival adaptation mechanisms of Rheum nobile in the high-altitude alpine environment of the Himalayas, this paper combines Finite Difference Time Domain (FDTD) optical simulation to investigate the thermoregulatory function of the densely packed spherical protrusion structures on its semi-transparent bracts. The greenhouse effect, as an effective strategy for maintaining suitable internal temperatures, typically requires high transmittance of shortwave solar radiation. Compared to ordinary rosette leaves, the bracts of Rheum nobile exhibit significantly enhanced solar radiation transmittance. Simulation analyses reveal that the surface protrusion structures enhance transmittance in the visible to near-infrared range, thereby more efficiently channeling solar radiation into the internal greenhouse space under strong sunlight and promoting the formation of the greenhouse effect. Further research shows that the hierarchical microstructure on the bract surface forms a graded refractive index layer, avoiding abrupt changes in refractive index and significantly suppressing light reflection, thereby improving transmittance efficiency. This enhanced transmittance enables Rheum nobile to effectively transfer environmental radiant heat into the greenhouse interior despite the limited volume of its bracts, providing new ideas for the design of bionic materials and systems related to radiation insulation.
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