A model representing isotope separation during water evaporation in plants was constructed. The model accounts for substance diffusion, convective transfer and evaporation from the surface of the leaves. The dependence of the system’s separation and enrichment coefficients on various parameters (liquid velocity, diffusion coefficient, and potential barriers for molecules and their thermal velocities) was determined. A comparison was made between the enrichment coefficients calculated from experimental data from different plants and those based on the model. Qualitative agreement between the experimental and theoretical values was obtained for the case of $$\frac{uh}{D} {\gg} 1$$uhD≫1, where u is the average velocity of water in the plant, h is the height of the plant, and D is the diffusion coefficient of the substance.

中文翻译：

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植物同位素分离模型

构建了代表植物水分蒸发过程中同位素分离的模型。该模型考虑了叶子表面的物质扩散、对流转移和蒸发。确定了系统的分离和富集系数对各种参数（液体速度、扩散系数和分子的潜在障碍及其热速度）的依赖性。将不同植物的实验数据计算的富集系数与基于模型的富集系数进行了比较。在 $$\frac{uh}{D} {\gg} 1$$uhD≫1 的情况下，获得了实验值和理论值之间的定性一致性，其中 u 是植物中水的平均速度，h 是植物的高度，D 是物质的扩散系数。