渗出对薄壁植物细胞受压力学行为的影响

为研究单个薄壁植物细胞的力学行为，采用内充液体的球形薄膜为细胞力学模型，在考虑细胞壁渗透规律的基础上，推导了模型的控制方程。该模型中假设细胞内物质为不可压缩液体，细胞壁为不可压缩超弹性薄膜；本构关系选用Moony的应变能函数；胞内液体在膨胀压作用下可透过膜渗出，渗出关系假定为单位渗透面积上的体积流量与膨胀压成正比。计算了该模型在承受一对刚性平板压缩时力学响应与液体渗出的关系。对模拟结果分析表明：细胞刚度随变形的增大而非线性增加，同时随细胞内部液体的渗出而减小；在等位移条件下细胞因液体渗出而出现松弛现象。

Effect of osmosis on mechanical behavior of parenchyma plant cell under compressive loading

An axisymmetric parenchyma fluid-filled spherical cell model was developed to study mechanical behavior of a single plant cell.The model consisted of an elastic soft thin wall enclosing incompressible liquid.The wall was assumed to be an incompressible super-elastic thin membrane with penetrability for inside fluid.The constitutive relation of the wall was chosen as Moony strain-energy function.The osmosis rate was assumed proportional to the cell turgor.The cell was compressed by two parallel rigid planes.The control equations were built using large deformation geometric relationship,and the solutions were obtained by numerical method.Using this model,principle stretch ratios and tensions in the wall,deformations of the cell and relationship between turgor and compressive force were obtained.It was found that the rigidity of plant cell increased nonlinearly with the cell's deformation.Furthermore,the osmosis made the cell relax under constant compressive deformation.