中文摘要：

葵花，高粱和玉米的茎木髓是自然细胞的材料。在这篇论文，这些木髓的作文的内容被决定，他们的房间形状和结构通过扫描电子显微镜(SEM ) 和光显微镜被检验。在测试部分机械性质以后，进一步的研究在机械性质上在作文的效果和木髓的结构被进行。结果证明全部的纤维素，半纤维素和每件样品的木质素内容接近它的主要房间墙的 75% 干燥质量。与 Rvalue 的秋天，相对主要作文的内容的一个参数，当他们的压力和刚硬增加时，细胞的木髓的灵活性下降。完成葵花木髓的基本房间形状是近似 tetrakaidehedron。高粱和玉米的茎木髓近由房间组成到六角的棱柱和罐头显著地在轴的方向增强他们的机械性质的一些管状的。

英文摘要：

The stem piths of sunflower, kaoliang and corn are natural cellular materials. In this paper, the contents of the compositions of these piths are determined and their cell shapes and structures are examined through scanning electron microscope （SEM） and optical microscope. Further research is conducted in the effects of the compositions and structures of the piths on the mechanical properties after testing the partial mechanical properties. The results show that the total cellulose, hemicelluloses and lignin content of each sample approaches 75% of the dry mass of its primary cell walls. With the fall of R value, a parameter relative to the contents of the main compositions, the flexibilities of the cellular piths de- scend while their stresses and rigidities increase. The basic cell shape making up the sunflower pith is approximately a tetrakaidehedron. The stem piths of kaoliang and corn are made up of cells close to hexangular prisms and a few tubular ones which can observably reinforce their mechanical properties in the axial directions.