木素胺的合成及改性率的测定

通过三因子二次回归正交设计试验，采用Mannich反应合成阳离子木素胺。用元素分析仪测定改性样品的含氮量，以电泳试验测定其改性率，含氮量和改性率之间线性相关，并对其表面活性进行了研究，得到影响含氮量和改性率的主要因素和最佳工艺条件。     

汞的超高灵敏显色反应及其应用

对Ｈｇ（Ⅱ）－ｍｅｓｏ－４－（４－ＴＭＡＰ）Ｐ－ＤＤＭＡＡ－Ｔｗｅｅｎ８０超高灵敏显色体系的特性进行了研究。该显色体系在ＰＨ８．５～１０．５的硼酸－氢氧化钠介质最为适宜，显色体系最大吸收波长为４５０ｎｍ处，摩尔吸光系数ε４５０＝４．８×１０＾５Ｌ／ｍｏｌ．ｃｍ，试剂空白在４５０ｎｍ处时等于零。在ＤＤＭＡＡ，Ｔｗｅｅｎ８０条件下，Ｈｇ＾２＋与Ｍｅｓｏ－４（４－ＴＭＡＰ）Ｐ的组成比为１：１。在０～１０     

胡敏酸与Fe3+络合反应稳定性及热力学特征研究

采用离子交换平衡法研究了在不同酸度、离子强度、温度条件下胡敏酸(HA)与Fe3 络合反应的稳定性和热力学特征.结果表明,在相同离子强度、反应温度条件下,随着pH的升高,HA与Fe3 络合表观稳定常数和配位数均增加,有利于络合反应的进行;相同pH和温度下,离子强度从0到0.10 mol·L-1,HA与Fe3 络合反应表观稳定常数和配位数增加,但离子强度从0.10 mol·L-1继续上升到0.15 mol·L-1,则上述2个特征常数呈现下降的趋势;胡敏酸络合Fe3 标准自由能变△Gθm、焓变△Hθm、熵变△S:在298.2、308.2 K温度下均为负值,反应是自发进行的放热反应,较低的温度有利于反应的进行.     

Exclusion of β-thalassaemia by biopsy and DNA amplification in mouse pre-embryos

Exclusion of β-thalassaemia in mice was undertaken by pre-implantation DNA diagnosis. Biopsies of approximately five cells were obtained from mouse pre-embryos. DNA prepared from this material was amplified by the polymerase chain reaction (PCR), enabling identification of the normal β-major globin gene in 11 out of 20 cases where it was known to be present. The expected negative result was obtained in 14 out of 16 homozygous thalassaemic embryos, with two false positives. Results are promptly available following PCR, thereby facilitating re-implantation of embryos which have had homozygous β-thalassaemia excluded. The mouse model illustrates a useful approach to pre-implantation diagnosis of genetic disease in the human.     

Reaction probabilities of ClONO2 on ice

ＩｎｔｒｏｄｕｃｔｉｏｎＴｈｅｏｚｏｎｅｈｏｌｅｈａｓｂｅｃｏｍｅａｓｅａｓｏｎａｌｐｈｅｎｏｍｅｎｏｎｉｎｓｏｕｔｈｐｏｌａｒｓｉｎｃｅｔｈｅｄｉｓｃｏｖｅｒｙｏｆＡｎｔａｒｃｔｉｃｏｚｏｎｅｈｏｌｅｉｎ1985(Ｆａｒｍａｎ,1985).Ｔｈｅｏｚｏｎｅｈｏ...     

Prenatal diagnosis of tyrosinase-negative oculocutaneous albinism by an electron microscopic dopa reaction test of fetal skin

An electron microscopic DOPA reaction test of fetal skin was used for the prenatal diagnosis of tyrosinase-negative oculocutaneous albinism (OCA). The subject was a 34-year-old Japanese woman in her second pregnancy. Her first child, born in 1982, had been previously examined and confirmed to have tyrosinase-negative OCA. The parents requested a prenatal diagnosis and we sampled skin from the upper trunk of the fetus. On conventional electron microscopy, the development of melanosomes in interfollicular melanocytes had progressed no further than stage II. Fetal skin samples incubated with L-DOPA solution indicated a lack of tyrosinase activity and showed that the melanosomes had not progressed beyond stage II. In skin samples from the trunks of three Japanese fetuses aborted for other reasons at 19–20 weeks of gestation, most premature melanosomes were further melanized to stage IV after incubation with L-DOPA solution. A prenatal diagnosis of tyrosinase-negative OCA was made. The parents requested a termination and skin biopsies of the abortus confirmed the diagnosis. This study shows that tyrosinase is normally present in melanocytes of the fetal epidermis at 20 weeks' gestation, and that the electron microscopic DOPA reaction test of a fetal skin biopsy specimen is safe and practical, and provides reliable information for making a prenatal diagnosis of tyrosinase-negative OCA in the second trimester.     

突发性环境污染事故的分类特征及处置措施——以保定市两起危及环境安全事故为例

环境污染事故具有时间上的突发性、形式不确定性、危害的严重性和处理处置的艰巨性.发生在河北省保定市境内的两起危及水环境安全的事故具有典型性和代表性.事故发生后通过采取一系列相应的应急措施,有效地控制了大规模的环境污染;如何防止和应对突发环境污染事故,维护环境安全,已成为环境保护工作的重大新课题.面对环境安全事故及跨流域、跨区域环境污染事故的频繁发生,应从排查污染隐患、建立完善的环境应急响应体系、加强环境应急基础设施建设等方面入手,减少事故的发生,减轻对环境的危害.     

铝电解含氟烟气治理技术

铝电解过程中产生大量含氟烟气，主要介绍目前国内几家铝厂所采用的含氟烟气治理技术，并对实际工作中存在的问题进行分析，供在类似工程中参考借鉴     

白洋淀底泥腐殖质的表征及光化学反应

白洋淀底泥腐殖质的表征及光化学反应郁志勇王文华彭安（中国科学院生态环境研究中心，环境水化学国家重点实验室，北京１０００８５）关键词腐殖质；单线态氧（１Ｏ２）；自由基（ＲＯＯ·、ＨＯ·）；光化学反应腐殖质是动植物经过长期的物理、化学、生物作用而形成的...     

含酚废水的Fenton试剂和光助 Fenton试剂降解研究

研究了在Fenton试剂和光助Fenton试剂作用下，苯酚降解的反应条件。研究结果表明。反应的时间、初始pH值、H2O2和Fe^2＋浓度对Fenton反应都有影响。常温下，当H2O2浓度为20mmol／L，Fe^2＋浓度为4mmol／L时，pH为1，反应时间为30min时，苯酚的转化率达到98％，矿化率达到65％以上。光助Fenton法可以大幅度提高含酚废水的降解率。