黄瓜叶肉细胞壁的微观力学性能

Micro-mechanics property of cucumber mesophyll cell wall

以黄瓜叶肉组织为研究对象,经过固定—脱水—包埋—切片处理后,在纳米压痕仪上进行单轴压缩试验.试验结果表明:在应力小于1.0 MPa时,细胞壁发生弹性变形,当应力大于1.0 MPa时,细胞壁会产生塑性变形;同时可以看出在弹性变形范围内,当应力小于0.4 MPa时,应力-应变关系呈线性关系,而应力大于0.4 MPa时,应力-应变呈现非线性特征.为了精确地表述细胞壁材料的力学特性,在对应力-应变数据进行分析的基础上,采用2参数的Mooney-Rivlin模型对试验数据进行拟合,得到模型参数C1和C2分别为0.792,0.195 MPa.

To investigate the micro-mechanical properties of cucumber mesophyll cell wall,the uniaxial compression experiment was carried out at nano-indentation tester after the treatments of fixing,dehydrating,embedding and slicing for mesophyll tissue.Loading-unloading curve shows that the cell wall deforms elastically when the stress is less than 1.0 MPa,and deforms plastically when the stress is more than 1.0 MPa.The stress-strain relationship is of linear for the stress less than 0.4 MPa,and with nonlinear relationship for the stress more than 0.4 MPa.In order to exactly describe the mechanical properties of cell wall,the Mooney-Ruvlin model with 2 parameters was used to regress experimental data.The deduced model parameters of C1 and C2 are 0.792 MPa and 0.195 MPa,respectively.