age class structure

英汉例句

But stand volume descents to a great extent, age class and stand density structure are maladjusted badly, and the number of stand growth is low.
但蓄积量大幅下降，林分的龄组、密度结构严重失调，林分生长量偏低。
The age class structure of Acanthopanax senticosus population was stable in the Quercus mongolica forest, but they were unstable in the theropencedrymion and secondary forest.
对不同生境下刺五加种群的年龄级结构、高度级结构和径级结构进行了研究。
In this paper, we establish a kind of new class age-structure SEIR epidemic model with impulsive vaccination and nonlinear infectivity, which contains ODEs and PDEs at the same time.
建立了一类新的带有脉冲接种的类年龄结构SEIR流行病模型，并考虑其具有非线性传染率。

Put simply, the market penalizes integration: The higher the percentage of blacks in the neighborhood, the less the home is worth, even when researchers control for age, social class, household structure, and geography.
FORBES: How Home Ownership Keeps Blacks Poorer Than Whites