冷等离子体对硅粉薄层的提纯研究

给出了冷等离子体对作为阴极的硅粉薄层的提纯方法及装置、提纯结果和规律。实验表明，在氮化氢气氛下，不仅可以除去９５％以上的许多过渡金属杂质，还可以除去许多非金属杂质。这种提纯硅的方法在研制太阳能电池材料方面具有好的应用前景。

Si(100)—As表面钝化作用和氧吸附

利用自己研制的具有分子束外延系统的表面分析联合谱仪研究了氧与Si(100)—As表面的相互作用。本文进一步证实了As层是Si表面的很好的钝化层,并首次研究了Si(100)—As表面的氧吸附全过程。实验表明,氧的饱和覆盖量为0.5单原子层,即Si表面上存在As原子层而使吸附位置减少一半。另外,通过吸附动力学分析得知,Si(100)—As表面的初始粘附系数是5.6×10^(-3),比清洁的Si(100)表面小一个数量级。Si表面上As的钝化作用是Si原子的悬挂键态被As原子的占有孤立对态代替而形成。

Purification Processes and Market Potential of Bromelain in Brazil

Bromelain is the denomination given to the group of endoproteases obtained from members of Bromeliacea family. These enzymes have a wide range of proven applications and have been an object of study for worldwide researchers for decades. Over the years, several different downstream processes were studied in order to determine which technique would be worthwhile to be implemented in Brazil and provide the national market with such product. The objective of the present study is to relate the main studies in Brazil that has proven that bromelain purification can be cost-effective, in addition to the well-known benefits owned by such enzymes, and highlight the applications that create their market potential in the Brazilian market.