次乙基

Poly/montmorillonite/2-Carboxyethyl phosphinic acid (PET/MMT/CEPP) nanocomposites were prepared through direct-esterification process by adding reactive flame retardant before esterification, and organic MMT was added before polycondensation.

采用直接酯化法，将共聚型阻燃剂羧乙基苯基次磷酸和对苯二甲酸以及乙二醇混合后酯化，在酯化产物中加入经过有机改性的蒙脱土，缩聚制备了阻燃聚酯／蒙脱土纳米复合材料(PET/MMT/CEPP)。

Divinylpyridine-9,9′-diethylfluorene nanoparticles were prepared by reprecipitation method.

利用二次沉淀法制备出不同粒径(101.6~516.9nm)的2，7-二乙烯吡啶基-9，9′-二乙基芴有机纳米微粒。

In the presence of the phase transfer catalysts such as tetramethylammonium bromide, tetraethylammonium bromide or polyethylene glycol(MW 400 and 6,000),lithium hydroxide is the best alkali among lithium hydroxide ,sodium hydroxide and potassium hydroxide.

研究表明在溴化四甲基铵、溴化四乙基铵、聚乙二醇（分子量为6，000）和聚乙二醇（分子量为400）相转移催化体系中，氢氧化锂最好，氢氧化钾次之，氢氧化钠最次。

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。