分光光度法COD的快速测定

化学需氧量是水体中有机物含量的重要指标。重铬酸钾法是测定化学需氧量的常规方法。在这个实验里，我们采用了COD的快速测定方法，对这种方法的准确度、精密度进行了分析，并对重铬酸钾法与快速测定法进行了对比实验，以验证其相关性。     

一种新型测氧微传感器的特点与应用

介绍了一种新型测氧微传感器的特点与应用。该测氧微传感器了有一个测量阴极外，还带有一个内保护阴极，其测量零电流很低，信号极稳定且易于制作 。该测同传感器由于尺寸小，稳定性高，不仅可方便的应用于常规环境测量中，而且还可使用于过去的因范围太小而无法进行测量的不少研究领域中。     

苏州河底泥的耗氧特征及其与水质的关系

苏州河上海区段底泥中SOD的数据分析表明,市区河段底泥中SOD的大小,与上层河水中COD_(Mn)、DO、BOD_5、NH_3-N的含量均有密切的相关性。在流动水相作用下,研究了水温及流速等主要环境因素对底泥耗氧的影响。提出了市区河段水质模式中的底泥耗氧表达式。指出在市区河段中,底泥耗氧在总的耗氧过程中灵敏度最大,占主要地位。若河流两旁无污染源排入时,约占该河流总耗氧的51％;     

负载型TiO2/活性炭的制备及光催化降解罗丹明B研究

通过溶胶-凝胶方法以活性炭(AC)为载体,制备负载型TiO2/AC,利用SEM、BET、XRD、Ranme、XPS对TiO2/AC的组成、结构、尺寸等特征进行分析和表征,并用紫外灯为光源,通过TiO2/AC、TiO2粉末和活性炭与TiO2粉末的混合物对可溶性罗丹明B的光催化降解效果的比较,探讨了TiO2/AC的光催化性能.结果表明,负载体中的TiO2是由30～60nm的球形颗粒组成,含有Ti,O,C等3种元素,颗粒间不发生团聚,其中一些C元素是由活性炭载体扩散到TiO2颗粒中的.由于活性炭载体与TiO2的协同作用以及高浓度Ti3+的影响,负载型TiO2/AC的光催化活性大.当TiO2/AC在250℃空气中热处理2h,再在氮气保护下500℃热处理2 h,TiO2的质量分数为(18±0.3)%时,负载型TiO2/AC对罗丹明B的光催化降解的表观反应常数k最大,为0.0077 min-1.     

纳米TiO2薄膜在不同基质表面的负载及光催化性能

以釉面陶瓷和普通钠钙玻璃为载体,用溶胶凝胶法在其表面进行了纳米TiO2薄膜的负载.采用X射线衍射法(XRD)、扫描电子显微镜(SEM)和X射线光电子能谱仪(XPS)对薄膜进行了表征与分析.结果表明,TiO2为完全的锐钛矿型,平均粒径约为15nm;TiO2薄膜在2种载体上分布均匀,膜厚约为300nm;TiO2薄膜在釉面陶瓷表面呈连续分布,而在玻璃表面上出现了破裂现象;2种载体中的一些基质离子在TiO2薄膜均有渗透.光降解实验表明,2种载体上的TiO2薄膜对亚甲基蓝的降解均符合一级反应动力学.TiO2/釉面陶瓷催化活性大于TiO2/玻璃,该薄膜对实际生产多菌灵废水具有催化降解作用.2种载体上的TiO2薄膜重复使用20次,对亚甲基蓝的去除率降低约2%.     

Gene therapy for cystic fibrosis: Will it affect the uptake of prenatal carrier screening?

We report a study which examined whether the decision of 135 couples to accept prenatal cystic fibrosis (CF) carrier screening would be influenced by the advent of gene therapy. A majority (91 couples; 67 per cent) felt that gene therapy for CF would not influence their decision to be screened. Twenty-two couples (16 per cent) stated that they would decline to be screened and an equal number felt ambivalent. Even if the life expectancy of a CF sufferer were increased by gene therapy to normal, 78 per cent of couples would still wish to avail themselves of prenatal carrier screening. A majority of women who decline screening do so because they are opposed to termination of pregnancy. The availability of gene therapy could increase the proportion of couples who accept screening.     

乳状液膜法萃取氨基酸的研究

本文以ＴＯＭＡＣ为载体，ＥＣＡ４３６０Ｊ为表面活性剂，内外相Ｃｌ＾－浓度梯度为推动力，研究了Ｌ－苯丙氨酸在乳状液膜体系中的传输，并对影响液膜萃取的各种因素进行了系统的阐述，确定了此体系的最佳膜相组成的实验条件，实现了Ｌ－苯丙氨酸的提取和浓缩。     

Monitoring of Gin Drinkers' Bay landfill,Hong Kong: I. Landfill gas on top of the landfill

The present study centered on the composition of landfill gas and its effects on soil and plants at the Gin Drinkers' Bay (GDB) landfill in Hong Kong This first part of the study was a whole-year monitoring of landfill gas composition in the gas ventilation system installed on top of the landfill Methane, carbon dioxide, oxygen, and ethylene were measured It was shown that gas generation was positively correlated with the amount of precipitation and air temperature and negatively correlated with atmospheric pressure     

固定化微生物技术及其在重金属废水处理中的应用

固定化微生物技术是一种有效的废水生物处理技术.较为全面地介绍了其定义、分类及载体选择.全面系统地介绍了固定化微生物(主要是菌类和藻类)技术近年来在重金属废水处理中的应用现状,分析认为,固定化微生物技术对于处理含各种重金属离子的废水均有很广阔的应用前景,并对今后的研究方向做了探讨.     

Effects of cadmium and zinc on oxygen consumption, ammonium excretion, and osmoregulation of white shrimp (Litopenaeus vannamei)

White shrimp, Litopenaeus vannamei, a globally important cultured prawn species, is an ideal animal for studying the impairment caused by the effects of heavy metals that are often detected in coastal areas. The main purpose of the present study was to detect the acute toxicity of Cd and Zn to L. vannamei, and to investigate their effects on gill functions, which have not been carried out in this species before, hoping to obtain some important significance. First of all, we examined the acute toxicity of cadmium (Cd) and zinc (Zn) to L. vannamei and obtained 24-, 48-, 72-, and 96-h medium lethal concentration (LC₅₀) values of 2.58, 1.30, 1.14, and 1.07 mg Cd l⁻¹ and 3.98, 2.14, 1.75, and 1.35 mg Zn l⁻¹, respectively. Furthermore, we also found that exposure of shrimp to Cd or Zn caused an inhibition in oxygen consumption of 91.3% and 75.9% lower than that of the control. However, after separate exposure to Cd or Zn, elevations in ammonium excretion were obtained, which were 153.7% and 144.1%, respectively, higher than the control. It is most likely that elevations in ammonium excretion were related to decreased osmotic pressure of shrimp blood. Finally, the distribution of Cd and Zn within gills was also determined.