林龄单因变量的蓄积量生长模型决定系数低，引入地位指数和密度指数再次参数化的生长模型可显著提高模型拟合度。

Single age variable stock volume growth model had low coefficient of determination, but it was improved a lot by introducing site index and stand density index in reparameterization.

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本文把环境温度梯度作为一个变量引入LEC法生长的理论模型中进行分析，得到了晶体中温度分布的表达式。

This paper presents an expression for temperature distribution in growing crystal by considering the ambient temperature gradient as a variable introduced in LEC model.

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结果表明，立木各器官变量之间存在着很好的相对生长关系；

The results showed that there is an allometric growth relationship among the organ variables.

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