Chromosome banding in direct preparations of chorionic villi

Chorionic villus sampling (CVS) is now currently offered for first trimester prenatal diagnosis of genetic disorders. Chromosome analysis of CVS in direct and culture preparations is possible using modifications of standard banding techniques. We summarize our experience in applying QFQ, GTG, RBG, CBG, DA/DAPI, NOR, and SC differentiation protocols to direct preparations. Characteristic chromosome regions are properly labelled by these techniques, and analysis of 300 band stage karyotypes is consistently achievable on GTG banded direct preparations. However, banding of CVS direct chromosomes has proved to be difficult, and the analysis needs to be backed up by culture preparations.     

NO在Cu—ZSM—5上的催化分解

从铜离子交换液温度，浓度，ＰＨ值，以及铜离子交换的次数，交换的有无中间焙烧这几方面详细地讨论了铜离子交换条件对所制Ｃｕ－ＺＳＭ－５催化剂ＮＯ分解活性的影响；并且考察了Ｃｕ－ＺＳＭ催化分解ＮＯ活性随空速。     

Preparation of nanoparticles with an environment-friendly approach

Developing various approaches for preparing high performance materials has long been topics and tasks both for scientists and for engineers.Despite that many methods have been developed for preparing nanomaterials,developing simple and environment-friendly ways for preparing nanomaterials is very attractive.A simple approach of synthesizing Fe3O4 nanoparticles by arc-discharge submerging in water was reported.The results showed that by this method Fe3O4 nanoparticles can be synthesized in large scale.The as-prepared Fe3O4 nanoparticles exhibit uniform spherical shape and their diameters varied with arc-discharging parameters.The experimental results showed that the size of the synthesized Fe3O4 nanoparticles can be controlled through adjusting the processing parameters.Since no vacuum system has been used,the synthesizing process is greatly simplified.In addition,only cheap deionized water and industrial iron bar are used and no pollution or harmful by-products are found in the synthesis process.It indicated that the present approach is a simple,low-cost and environment-friendly for preparing nanoparticles.     

选煤厂噪声防治

分析选煤生产过程中噪声对人体的危害性，根据噪声的特点，采取适当控制方法，取得明显效果。     

核桃果皮基磁性固体酸催化剂的制备及其催化性能研究

采用自底向上策略,利用农业废弃物核桃青果皮制备了磁性碳质固体酸催化剂,并对其进行了BET、XRD、SEM、IR和TGA等表征分析.结果表明,合成的磁性固体酸催化剂结构蓬松,比表面积大,具有良好的热稳定性.催化剂MPCs-0.2-SO₃H在生物柴油的合成中具有良好的催化活性.当醇油比为30,催化剂加入量为油酸质量的7%,80℃反应8 h酯化率达到74.2%,比商用Amberlyst-15催化剂的酯化率高近20%,最高含水量可达油酸质量的4%,重复使用3次后仍具有较高的酯化率,不仅实现了废弃物的资源化,而且得到的催化剂磁性易分离,在生物柴油的合成中具有巨大的应用潜能.     

微生物絮凝剂的制备与发展方向

文章对无机絮凝剂、有机合成高分子絮凝剂和微生物絮凝剂三种絮凝剂进行了比较,提出研究和开发絮凝效果好、应用范围广、易生物降解、对环境安全的微生物絮凝剂就成为必然,并综述了微生物絮凝剂其产生菌的筛选、鉴定、培养、微生物絮凝剂的提取和纯化、微生物絮凝剂的化学组成分析和合成途径的探索;列举了微生物絮凝剂对畜产废水有机物的去除、对废水中COD、BOD的去除、对印染废水脱色的应用、对工业废水重金属离子的脱除,最后,展望了微生物絮凝剂的研究发展方向。     

固相微量萃取技术

固相微量萃取（ＳＰＭＥ）法是一种新颖的样品处理方法。该文较详细地介绍了此法的原理、操作和应用等，并比较了此法与其它几种样品处理方法的优缺点。ＳＰＭＥ法的特点是简便、快速、灵敏、实用、经济、而且不会造成两次污染，有很好的发展前途。     

用废旧锌锰电池制备锰锌铁氧体的研究

用水热法以废旧锌锰电池为原料对制备锰锌铁氧体进行了研究。探索了制备过程的影响因素,如水热反应的pH值、水热温度及水热时间等。结果表明,在溶液的pH值为10,水热温度为210℃,水热时间为2～24h时,均能有效制备无杂相的锰锌铁氧体;提高反应温度和延长反应时间,均有利于锰锌铁氧体的晶化过程。研究还发现,加入铁粉是一个既能高效除汞,又能制备高性能锰锌铁氧体的关键所在。      

壳聚糖作为絮凝剂的研究进展

壳聚糖是一种新型的天然高分子絮凝剂,在水处理中展现广泛的应用前景。综述了壳聚糖制备,在水处理中的应用及其絮凝机理等。研究表明,壳聚糖良好的絮凝性能,使其在废水处理和资源回收等方面的效果均优于无机及有机合成的絮凝剂,是一种环境友好的高效絮凝剂。     

铁负载型催化剂在废水处理中的应用

难降解工业废水已成为水处理中的一大难题,高级氧化技术可处理此类难降解废水,而铁负载型催化剂可提高反应的效率,降低反应条件。本文根据国内外文献将铁负载型催化剂进行了分类,主要分为负载FexOy的催化剂和Fe2+/Fe3+固体催化剂,并对不同活性物质的铁负载型催化剂的制备方法及其应用现状进行了分析,同时对今后的研究方向进行了展望。