叶片背面

卵单产于叶片背面，卵期3～8d；

The eggs , deposited single on the underside of leaves hatch in 3 to 8 days .

成虫羽化后于次日清晨5：00～6：00开始交配，持续交配1.5～3h，交配后不久在叶片背面产卵，单个散产，平均单雌产卵40余粒。

- 6 o clock in the next morning after emergence , the adults begin to copulate , each copulation last 1.5-3 hours , and lay 40 or more eggs per female singly on the lower surfaces of apple leaves .

基部的秆节间的具苍绿色条纹；叶片背面无毛。

Basal culm internodes with pale green stripes ; leaf blade abaxially glabrous .

提出了双流道泵无过载性能预测的计算方法：！2应取叶片背面出口安放角；

In this thesis a non-overload performance forecasting method of the double-channel pump was provided : β 2 is the blade back outlet angle ;

得到了压力分布图和速度矢量分布图，知道了汽蚀初生的位置在叶片背面进口稍后处。

We obtained pressure and velocity vector distribution , knew the location of cavitation born later in the leaves at the back of imports .

草莓品种对蚜虫抗性与叶片背面的茸毛密度成正相关，与气孔密度呈显著负相关；与叶片的木质素含量成正比；

The resistance of strawberry to aphids was positively related to the density of pubescences and the content of lignose , and negatively to the content density of stomas .

Ching相似，但叶片的背面密被绒毛，表面被短柔毛，侧生羽片9–16对。

Ching in size , but differs by its lamina being tomentose on the lower surface and pubescent on the upper surface and having 9 – 16 pairs of lateral pinnae .

三门峡电站水轮机运行约20000h以后，叶片正面和背面的根部断面出现裂绞。

Since the turbines of Sanmenxia power station have been put into operation about 20000 hours , cracks appeared on both front and back side at the root section of the blades .

当年小枝粗壮，2肋；干燥时的叶片厚革质，背面的红棕色；萼片短柔毛。

Current year branchlets stout , 2-ribbed ; leaf blade thickly leathery , abaxially reddish brown when dry ; sepals pubescent .

计算结果表明，在大部分长短叶片的通道内，射流区偏向于叶片背面，尾迹区则位于叶片工作面出口附近。

The calculation result shows that the jet zone transferred to the back of the blades , and the wake zone was near the exit of the pressure side of the blades in the most passing-ways of the split blades .

在叶轮的长短叶片方案中，本文首次采用了短叶片进口边向长叶片背面偏置的方法，从而使泵的能量性能进一步提高。

In design of impeller with long and short blades , first adopted is leading edge of short-blade biased toward the back of long one so as to further improve energy performances of pumps .

在轴垂面内，叶片之间的低速区和高压区都在叶片的工作面，高速区和低压区都在叶片的背面。

A zone with high pressure or low relative velocity exists in the blade pressure side in blade-to-blade plane .