Au/ZnO催化剂的表征及常温常湿 条件下CO氧化性能研究

常温下考察了焙烧温度、金含量及水分对Au/ZnO催化剂上CO氧化性能的影响 ,并在常湿条件下考察了ZnO上CO氧化活性同温度的关系。结果表明 ,金的存在极大地提高了催化剂CO的氧化活性。另外焙烧温度和金含量对Au/ZnO催化剂的活性和稳定性均有较大影响 ,在常温常湿条件下 ,2 4 0℃焙烧的 2 %Au/ZnO催化剂 ,可连续反应 1 750h保持CO完全转化。XRD结果表明 ,锌的化学状态对催化剂的稳定性有较大的影响 ,氧化锌较碳酸锌表现出较高的稳定性。     

生物除磷机理及试验研究

介绍了生物除磷机理、生物除磷系统的积磷细菌、生物除磷所需的环境条件。SBR法除磷的试验研究表明,应用SBR活性污泥系统进行除磷,需要一定的厌氧条件;且须在厌氧阶段进行充足的曝气。试验结果证明,SBR法在时间上控制的灵活性非常适合生物除磷的环境条件。厌氧与好氧相结合,能够提高磷的去除率或降低出水磷的浓度,磷的去除率可达90%左右。     

铁蓝—活性炭生物膜法处理彩色胶片水洗废水的研究

定影漂白废话水用铁蓝法预处理，结果表明，以硫酸亚铁为沉淀剂，投加量为铁氰化物理论值的１．３倍，ＣＮ去除率为９８％，反应生成的普鲁士蓝纯度较高，可供综合利用，铁蓝法除ＣＮ后的出水与显影冲洗废水混合，再经生炭生物膜法处理，ＣＯＤｃｒ去除率为８０％；     

Genetic amniocentesis in biamniotic twin pregnancies by a single transabdominal insertion of the needle

We present a technique to aspirate amniotic fluid from both sacs in biamniotic twin pregnancies using a single abdominal insertion with a spinal needle. It was successful in 48 out of 55 cases of biamniotic twin pregnancies referred to our perinatal unit between 1985 and 1994. The single insertion technique was used when the inter-amniotic membrane was clearly evident and two separate free amniotic fluid pools could be reached by the operator with a single puncture. An adequate amount of amniotic fluid was sampled from both sacs to make a cytogenetic diagnosis in all cases. There were four fetuses with trisomy 21 in three twin pregnancies. In two cases, only one twin was affected whilst the co-twin was normal, so that a selective feticide was performed. No miscarriages due to genetic amniocentesis were reported. After 1990, all genetic amniocenteses in biamniotic twin pregnancies (except for one case due to late booking) were performed between 14 and 15 weeks of gestation and with all cases except one, it was possible to sample both twins by a single puncture. We suggest that early amniocentesis (14–15 weeks) by a single abdominal puncture could be a reliable and safe alternative to first-trimester chorionic villus sampling in twin pregnancies.     

Thyroid antibodies are not a risk factor for pregnancies with down syndrome

The observation that thyroid disease is frequent in mothers of children with Down syndrome (DS) has suggested that maternal thyroid antibodies could be a factor predisposing to trisomy 21 in their offspring. In this study, the incidences of thyroglobulin (Tg) and thyroid peroxidase (TPO) antibodies were analysed with a sensitive solid-phase immunosorbent radioassay in sera from 29 mothers giving birth to children with trisomy 21 and 87 control mothers. The serum samples were collected at delivery. There was no statistical difference regarding the proportion of thyroid antibodies (against Tg and/or TPO) in the two groups. Thyroid antibodies were detected in 6/29 (20.7 per cent) of the DS mothers and in 23/87 (26.4 per cent) of the control mothers. Among the women with thyroid antibodies, 4/6 (66.7 per cent) of the DS mothers and 12/23 (52 per cent) of the control mothers had antibodies against both Tg and TPO. There was no increase in the relative risk of having a child with DS if the titre of either Tg or TPO antibodies or both were positive, i.e. ≥ 1/5. The results indicate that the presence of thyroid antibodies in the serum of a pregnant woman has no prognostic value for the birth of an infant with DS.     

沈阳市大气污染防治对策

本文根据沈阳市的大气污染现状，分析了大气污染形成的原因和特点及影响大气环境质量的主要因素，确定了大气环境质量目标。并提出了近期和２０００年的大气污染防治对策．     

木质素降解酶及其调控机理研究的进展

近年来有关木质素降解微生物和木质素降解酶的产与调控机理的研究表明，腐霉和细菌在木质自然降解中起着重要作用，腐霉的降解作用发生在次级代谢阶段，而细菌发生在初级代谢阶段，影响木质素降解酶的产生酶活力高低的因素有碳氮的选择与限制；诱导物的添加；表面活性剂的使用；某些金属离子浓度水平的改变；菌丝的固定化，温度和摇床转速的变换等。     

“华夏古陆”考异

自葛利普创名“华夏古陆”以来,经过半个多世纪的论辩与考订,对其地质构造属性,至今仍然否定与肯定交迭起伏,莫衷一是,本文从推覆构造,陆地漂移等实际资料着手,加以论证,认为它是经历深刻改造和发生巨大位移的变质岩断片体,地质构造属性已非“华夏古陆”原义。     

关于Marpol 73／78附则VI的出台经过及对策

介绍国际海事组织海上环境保护委员会关于Ｍａｒｐｏｌ ７３／７８公约附则ＶＩ的有关焦点问题的讨论情况，该附则Ⅵ业已以议定书形式被外交大会通过。它所涉及的范围较广，技术设备难度大，为贯彻落实该规则尚须在管理上，船舶设备条件等方面下功夫，以满足公约防止船舶对大气污染的要求。     

烟气脱硫工艺的选择

论述了现今国内外烟气脱硫的现状及烟气脱硫工艺的分类，国内外较为先进的烟气脱硫工艺的机理及特点，且对不同的脱硫技术的优缺点进行了全面的比较，对需要进行脱硫的装置现状了科学地分析，并最终提出选择合理的脱硫工艺的方法及注意的问题。