树冠层

Sometimes the neighbour's pigeons land on my windowledge Cooing softly Where the great poplar at the window has somehow grown beyond the fourth-floor roof They skim round its crown and back The sunlight on their fluffy feathers Alive day by day I keep coming indoors empty-handed And throwing book and jacket on the bed As the days hurry by I can bring scarcely anything home Even after days away Only you remain and the little room Living day by day We have grown used By an unspoken pact to the room's breadth A pair of pigeons cooing softly on the windowledge Which at many instants belong to us Day by day Dust that falls on book spines gradually yellows Perhaps it is otherwise That life, if it does, provides I know that the unwitting request is not excessive And that summer turns to autumn Perhaps fallen leaves will swirl after a night of rain It does not mean a return to green shade deep in sunlight A house-cleaning when leisure affords Feelings may come on latent even as Irrelevancies are spoken softly The instant when a first trembling on the lips teaches you happiness Lasts till the end of life A request always voiced unwittingly

有时候，邻家的鸽子落在我的窗台上咕咕地轻啼窗口的大杨树不知不觉间已高过了四层楼的屋顶它们轻绕那些树冠又飞回来阳光在蓬松的羽毛上那么温柔生命日复一日我往往空着手从街上回来把书和上衣掷在床上日子过得匆匆忙忙我时常不能带回来什么即使离家数日只留下你和这小小的屋子生活日复一日面对无声无息的默契我们已习惯了彼此间的宽容一对鸽子在窗台上咕咕地轻啼他们在许多瞬间属于我们日复一日灰尘落在书脊上渐渐变黄如果生活时时在给予那也许是另一回事我知道，那无意间提出的请求并不过份我知道，夏日正转向秋天也许一场夜雨过后就会落叶纷飞不是说再回到阳光下幽深的绿荫日子需要闲遐的时候把家收拾干净，即使轻声述说些无关紧要的事情感也会在其间潜潜走过当唇际间最初的战栗使你感知了幸福这一瞬已延伸到了生命的尽头而那些请求都是无意间说出的

Arborescent stratum; tree layer

森林群落中由高大的乔木树冠构成的一层。

Based on the investigation and analysis of the Cupressus funebris seed orchard at Laoshan Island in the Qiandao Lake, Zhejiang province, the ecological characteristics of the male cone, female cone and pollen have been studied.

本文以浙江省千岛湖姥山林场柏木种子园为对象，对柏木球花及花粉的生态学特性进行了研究结果表明，柏木的雌雄球花在树冠中呈成层分布；降雨时，雄球花对花粉具有保护功能；柏木花粉体积小，重量轻，花粉量大，花粉的散发受气温、风力、相对湿度和气压的综合影响，其中气温是主导因子，风左右着花粉的传播，降雨加速花粉的沉降。

The trees had a light delicate foliage, the structure of which was different from that of the trees in Europe; it did not grow in bows or cupolas, but in horizontal layers, and the formation gave to the tall solitary trees a likeness to the palms, or a heroic and romantic air like full rigged ships with their sails clewed up, and to the edge of a wood a strange appearance as if the whole wood were faintly vibrating.

树木都长着轻巧而细致的枝叶，它们的构造和欧洲树木的结构不同；树冠并非长成弓形或者球型，而是一层一层的生长，让树看起来就像一个个手掌，或者有一种类似升起风帆整装待发的帆船的豪气而浪漫的感觉，森林的边缘也有一种怪异的样子，似乎整个森林都在轻轻摇摆。

The stemwood growth (D2H) was positively related to total leaf area, surface area of crown and crown shape ratio, but negatively related to leaf area index and crown layer density.

材积生长与全树总叶面积TLA、树冠表面积TCA和冠型率CSR呈极显著正相关而与叶面积指数LAI、冠层密度CLD呈负相关。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。