饮用水中五种有机磷农药的快速检测法

本文介绍了使用Ｗａｔｅｒｓ ＯＡＳＩＳ－ＨＬＢ固相萃取小柱从水中分离富集敌百虫、敌敌畏、乐果、甲基对硫磷，对硫磷五种有机磷农药的快速检测法。     

电极流动分析仪的研制和应用

采用固定电极测试状态的方法，将流动技术引入到离子电极直接电位分析法中，设计并试制了电极流动分析仪。配用市售硝酸根电极、钠电极、氟电极、氯电极和氨电极进行了环境样品的测定。结果表明，电极流动分析仪法的分析速度比直接电位法提高２－３倍，变异系数，２．９％－５．０％之间，回收率在９０％－１０５％之间；直接电位法变异系数在２．３％－６．７％之间，加收率在９０％－１０９％之间。     

The association between alpha-fetoprotein and βhcg levels prior to and following chorionic villus sampling in cases that spontaneously miscarried

Maternal serum alpha-fetoprotein (AFP) and beta-human chorionic gonadotropin (βhCG) measurements taken prior to chorionic villus sampling (CVS) in 21 patients who subsequently miscarried were compared with measurements in a control group of 113 patients with uneventful pregnancies. Patients with AFP levels of 10 iu/ml or more prior to the CVS had a 4·3 times greater risk of miscarriage (95 per cent confidence interval 1·3–13·6). AFP levels obtained 1 week after the CVS in the 13 patients with late miscarriages were higher than in the control group (P = 0·06). Patients miscarrying had a greater rise in AFP (P = 0·06) and a greater fall in βhCG levels (P = 0·04) following the CVS procedure, compared with the control subjects. Each 10-unit change in the difference between AFP or βhCG levels prior to and 1 week following the CVS was associated with a significantly increased risk for late miscarriage. Elevated maternal serum AFP levels early in pregnancy and changes in AFP and βhCG levels following CVS may predict an increased risk for subsequent miscarriage.     

Use of the chemical cleavage of mismatch method for prenatal deficiency diagnosis of alpha-1-antitrypsin

The most common mutation in alpha-1-antitrypsin deficiency, conversion of a G to an A at base 9989 (PI-Z), was detected with the chemical cleavage of mismatch method, demonstrating the power of the method for prenatal diagnosis. Exon V of the gene was amplified using the polymerase chain reaction and heteroduplexes were formed to test for the presence of the mutation. The predicted C mismatch was readily detectable with hydroxylamine, and by making the probe from the chorionic villus sample it was possible to determine that the fetus was heterozygous, not homozygous, for the mutation.     

假单胞菌的氯儿茶酚1,2-双加氧酶基因的克隆和表达

 从土壤中分离得到1株降解2,4-二氯酚(2,4-DCP)能力较强的细菌菌株GT241-1,克隆了该菌株的3,5-二氯儿茶酚1,2-双加氧酶基因(dcpB),采用的克隆策略为:用Southern杂交对dcpB进行定位后,构建重组质粒,再用斑点杂交从重组质粒中筛选目的转化子.经序列测定得知dcpB亚克隆片段全长4303bp,其中dcpB基因编码区765bp.核苷酸和推测的氨基酸序列分析表明,dcpB与已在GenBank登记的相关基因有一定的差异.dcpB基因能够在大肠杆菌转化子中成功地表达有生物活性的酶.     

Effects of bifenthrin on Daphnia magna during chronic toxicity test and the recovery test

IntroductionWiththedevelopmentandapplicationofnewpesticide ,insecticidehasgreatlyreducedtheharmofpesttocrops .Bifenthrinisaneffectivepyrethroidinsecticideandacaricideagainstawiderangeofinsectpests ,anditisverypoisonoustomammal,aquatic .Thisinsecticideiswi…     

兰州市交通要道颗粒物污染状况及其致突变活性的研究

采用现场监测，色－质联用分析以及小鼠骨髓微核试验方法，评价了兰州市交通要道颗粒物的污染状况，分析了颗粒提取物（PE）的有机组成及致突变活性。结果表明，兰州市总悬浮颗粒物（TSP）污染严重。颗粒提取物中含有近100种有机化合物，其中包括致癌性多环芳烃。微核试验显示PE具有致突变活性，对人群健康的影响不容忽视。     

SBR法运行控制工艺研究进展

SBR法是一种具有独特的优点的废水生物处理工艺，但至今还没有一套公认的运行控制工艺，本文从SBR法的启动，充水时间及反应时间的确定，模糊控制，目标控制操作等几方面对SBR工艺的运行控制做了评述，并对其今后的研究方向做了展望。     

镀液循环流量对封闭循环电沉积Ni-SiC复合镀层的影响

目的 研究封闭式镀液循环装置中不同镀液循环流量对Ni-SiC复合镀层的影响规律,优化镀液循环流量参数.方法 以Q235管状工件为待镀基体,以添加SiC颗粒的改良瓦特镀液为母液,在自主研发的封闭式镀液循环电镀装置中以0.3、0.5、0.7 m3/h的镀液循环流量于管件内壁制备Ni-SiC复合镀层,通过SEM检测、XRD测试、硬度测试和摩擦磨损性能测试等手段,对各Ni-SiC复合镀层宏微观形貌、厚度、成分、结构、硬度和耐磨性进行分析研究.结果 在0.5 m3/h流量条件下,镀层厚度为32.98μm,SiC颗粒含量为15.37％,镀层晶粒尺寸和硬度分别为10.84 nm和704HK0.245,该条件下制备的Ni-SiC复合镀层具有最佳耐磨性,摩擦系数为0.41,体积磨损率仅2.83×10–5 mm3/Nm.结论 在不同镀液循环流量参数下,采用该封闭式循环电镀装置,均可制得均匀完整的Ni-SiC复合镀层.随镀液循环流量的升高,镀层厚度和SiC颗粒体积含量均降低,镀层颜色金属光泽增强,镀层晶粒尺寸先减小、后增大,镀层硬度则先升高、后降低.     

煤炭燃烧排砷水平与控制技术研究

煤炭是我国目前的主要一次能源之一,燃煤中的重金属污染愈来愈受到重视,如何控制煤炭中砷向环境中扩散,减轻环境污染是近年来重要的研究课题.通过开展对铁法煤业集团内部高砷煤和低砷煤的动力配煤燃烧试验,分析动力配煤燃烧过程中的砷迁移水平,研究铁法煤业集团内部动力配煤燃烧过程中的砷迁移规律和动力配煤降砷的可行性,并为开展最佳动力配煤操作数据提供理论依据,为高砷煤燃烧控制砷的排放寻找治理途径,提高煤炭资源的最大利用效率.