The middle layer of laminae is brought about either by submarginal initials of by the first cell of the abaxial layer of mesophyll alone or by both of them. 幼叶中层既可由亚边缘原始细胞或远轴层叶肉的第一个细胞单独产生,也可由它们二者共同产生。
The feasibility of which short-hole shrinkage method is used for mining of low-grade and submarginal ores in Huanren Mine is demonstrated in this paper. 论证了采用浅孔留矿法对桓仁矿北岔区的低品位矿及表外矿进行综合回收的可行性。