With the appearance observation and the determination of the contents of Cr,Zn,Pb,Mn,Fe,Cu and S in different ages of needles of Pinus.
ExEndl)不同年龄针叶中Cr,Zn,Pb,Mn,Fe,Cu等重金属元素及元素S质量分数的分析,探讨了它们与北京大气污染之间的关系。
The influence of PFI beating on fibre and handsheet properties of hardwood and softwood kraft pulps was investigated.
研究了针叶木和阔叶木硫酸盐浆PFI打浆对各自纤维性质及浆张性能的影响。