摘要:
对土—根系统养分运移对流-弥散方程用MATLAB语言编写土壤氮磷钾养分运移基本方程求数值解程序,结果表明,与专业软件Uptake相比,供试植物的氮磷钾总吸收量的相对误差分别只有+2.94%、-1.35%和+2.83%。程序能绘制生动美观的二维图形;数值解采用有限元法,较好地克服了Uptake软件有限差分法收敛较慢、积分区间内各节点解值相对精度不均匀的缺陷;程序简短高效,易于使用和维护。该程序只要稍加修改,就可用于求解目前各种CDE改进方程和土壤水分运动方程,从而使该领域复杂数学问题的求解变成简单易行。
Abstract:
An improved method for the numerical simulation of convective-dispersive equation(CDE) by using MATLAB language was developed.The program d0201.m was applied to implement basic CDE model for the numerical simulation.Compared with the professional Uptake software,the newly developed method rendered relative errors on the total N,P and K absorptions to be +2.94%,-1.35% and +2.83%,respectively.This program can produce attractive two-dimensional illustrations.It employs finite element method,which overcomes the Uptake's low convergence rate associated with the finite differentiation method,as well as the inconsistent accuracy at the nodes of integral interval.The new program was simple,efficient,and easy to use and maintain.Furthermore,with slight modification,the program could be applied to solve diverse CDE models for amelioration and water movement in soil.The MATLAB language simplifies complex mathematic calculations and makes the modeling process more user friendly than the Uptake.
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