The process of structuring the multi-lateral horizontal well productivity formula was carefully studied, and two theory defects and three mathematical approximation were detected.
本文仔细研究了分支水平井产能公式的架构过程，发现存在两处理论缺陷和三次数学近似。
The engine mathematical model in the simulation system is obtained by approximation of testing data of an actual engine with a series of small deviation and linearized models.
仿真系统中的发动机数学模型是用一系列小偏差线化模型去逼进某一实际发动机的试车数据而得到的。
The first part deals with the fundamental physical assumptions and mathematical model, while the second part describes finite-element approximation and method of calculations.
第一部分提出了基本的物理假定，讨论了数学模型；第二部分是有限元逼近和计算方法的讨论。
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