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nucellus n.(pl. -celli ) 【植物;植物學】珠心。n...

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Abstract : double steel - ball extrusion deep hole solves the matching problem of steel - ball nucellus with workpiece axis , using this technology , extruding deep hole with smaudiameter is attained efficiently with high quality . it has been proved that the special problem of finishing curved hole is able to be solved 文摘:雙珠式擠壓深孔有效地解決了鋼珠珠心與工件軸心重合的問題,高質高效地實現了較小直徑深孔的擠壓加工,實踐證明,且能實現彎孔的高精加工。

Enclosure of the nucellus by the integuments is incomplete , the embryo sac or , in gymnosperms , to the archegonium 珠被并不是將珠心完全封閉,而是留有珠孔以便受精時花粉管進入胚囊,或裸子植物的藏卵器。

In endospermic seeds the endosperm replaces the nucellus and is often a rich source of growth - regulating substances 在有胚乳種子中,胚乳取代珠心,成為生長調節物質(應為營養物質譯者注)的豐富來源。

Chalaza ( pl . chalaxae or chalazas ) the region of an angiosperm ovule where the nucellus and integuments merge 合點:被子植物胚珠上的一個區域,在合點處珠心和珠被愈合。

The cells of the integument and nucellus of some plants form perfectly normal embryos . 某些植物的珠被和珠心細胞形成完全正常的胚。

The nucellus is usually degraded and absorbed as the endosperm develops . 珠心通常在胚乳發育時被分解和吸收。