variation n. 1.变化,变动。 2.变量,变度,偏差。 3.【语言】语尾变化;变体,异体;【数学】变分,协变;顺列;【生物学】变异,演变,变种;【音乐】变奏曲;【天文学】变差;(月的)二均差;【物理学】磁差。 a principle without variation 不变的方针[原则]。 be capable of variation 可能变化。 be liable to variation 容易变化。 These prices are subject to variation. 上列价格可能变更。 adj. -al
Thickness of upper and lower epidermis of leaves , width of xylem and phloem of annual and biennial branches , ratio of late wood to early wood , periderm thickness of biennial branches , and length of xylem ray present decreasing trends with latitude ascending ; while ratio of palisade tissue to spongy tissue , epidermis thickness of annual branches , and cortex thickness of biennial branches show unobvious variations with latitude increasing 叶的上下表皮厚度、 1和2年生枝木质部及韧皮部宽度、晚材早材比值、 2年生枝的周皮厚度、木射线长等均随纬度升高而呈下降趋势;而叶的栅栏组织和海绵组织比值、 1年生枝表皮厚度、 2年生皮层厚度等解剖结构随纬度变化没有明显规律。