Thonemann P C, Evans C J
J Gen Microbiol. 1976 Jan;92(1):25-31. doi: 10.1099/00221287-92-1-25.
The dispersal of an initial concentration of identical Brownian particles is accurately described by the solution of the conventional diffusion equation, and a diffusion coefficient can be assigned to the assembly of particles. However, the dispersal of an initial concentration of motile bacteria is not well described by the same solution, in spite of the similarity between the random motion of a bacterium and a Brownian particle. Reasons for the failure of the Gaussian solution of the diffusion equation to describe the dispersal of Escherichia coli are discussed. An equation is formulated which gives the concentration of dispersing organisms as a function of space and time if the speed distribution function of the assembly of organism is known and reproduction is suppressed. For three assumed speed distributions the results are compared with concentrations measured by previous authors.
初始浓度相同的布朗粒子的扩散可以通过传统扩散方程的解准确描述，并且可以为粒子集合赋予一个扩散系数。然而，尽管细菌的随机运动与布朗粒子有相似之处，但初始浓度的活动细菌的扩散并不能用相同的解很好地描述。讨论了扩散方程的高斯解无法描述大肠杆菌扩散的原因。如果已知生物集合的速度分布函数且繁殖受到抑制，可推导出一个方程，该方程能给出作为空间和时间函数的扩散生物的浓度。针对三种假设的速度分布，将结果与先前作者测量的浓度进行了比较。
