The carbon microfiltration membranes were prepared by pyrolysis of a home - made thermosetting phenol - formaldehyde ( PF ) resin .实验合成了球形热固性 酚醛树脂 微粒,并以此为原料制备了微滤炭膜.The preparation and property of urea - formaldehyde resi...
The material is readily prepared by reaction of formaldehyde and hydrazine.这种物质很容易由甲醛和肼反应而得到.Formaldehyde slowly inactivates many viruses.甲醛能慢慢使多种病毒失去活性.Sulfur dioxide and formaldehyde both produce irritation.二氧化硫和甲醛都可产生...
有形的检查或检测也可代替正式的听证.Physical inspections or tests may also take the place of formal hearings.需要的不是有形的永久性, 而只是理想的永久性.No physical permanence, but only an ideal one, is necessary.我猜想,思特里克兰德在有形的事物上模模糊糊地看到某种精神意义.I fancy that St...