不同出口山脚约束的泥石流淤埋实验研究

汶川8.0级地震后,在灾后重建的过程中,很多位于泥石流沟口堆积区的居民建筑、交通干线、临时设施等都不可避免会遭受到泥石流的威胁.不同泥石流沟堆积区两侧山脚的夹角都有所不同,其对泥石流在堆积区的淤埋情况也会有所影响.针对此种情况,开展了18组室内实验,探讨出山口山脚约束对泥石流淤埋的影响.实验结果表明,随着约束程度的加大,泥石流扇状地的淤埋宽度随之减小,淤埋长度和厚度随之而增大,泥石流淤埋危险有向下游推进的趋势.     

紫外消毒系统有效辐射剂量测试方法研究进展

近年来,紫外消毒技术在水处理领域的应用越来越广泛,然而关于其辐射剂量的测试方法在国内外的发展还较为缓慢,特别是目前国内还没有机构能够采用标准的生物剂量法来对紫外消毒系统内部的有效辐射剂量进行验证. 因此介绍了国际上几种主要的紫外剂量测试方法,包括生物剂量法、化学法和模型计算法,并分析了各自的优缺点和应用中存在的问题,同时探讨了几种新开发的测试方法及其应用前景,以期为紫外消毒技术在水处理领域的推广应用提供支持.     

食蚊鱼(Gambusia afinis)cat、gapdh和gst基因的克隆及其在生态毒理学中的应用

根据Ensembl、Genbank登录的鱼类cat、gapdh和gst基因的CDS序列设计普通PCR扩增引物,寻找食蚊鱼的cat、gapdh和gst基因的c DNA片段,并根据定量引物设计要求设计出相应的SYBR Green I荧光定量RT-q PCR引物,建立了食蚊鱼cat、gapdh和gst基因的SYBR Green I荧光定量RT-q PCR方法。该方法在104~108数量级范围内有良好线性关系(R=0.999~1.000);熔解曲线显示扩增产物特异性良好,均为单一峰值;质粒标准品最高浓度与最低浓度的批内试验变异系数与批间试验变异系数均低于2%。利用该方法监测和评价环境污染物对水生生物的影响,选择了水体中常见典型药物污染物——双氯芬酸,研究其对食蚊鱼抗氧化基因表达的影响。结果表明,雌性食蚊鱼暴露在不同浓度双氯芬酸钠(0.005、0.05、0.5和5 mg·L-1)24 h后,其肝脏cat、gapdh和gst的mRNA呈现显著变化,相对于对照组,在低浓度0.005 mg·L-1时,cat与gst mRNA的表达量均有极显著上升(p0.01),而其它浓度均极显著下降(p0.01)。试验表明该方法具有快速、精确、灵敏度高的优点,可为利用该类小型鱼类的原位污染物的生物监测和生态毒理评价提供有力的技术支持。     

Effects of humic acid fractions with different polarities on photodegradation of 2,4-D in aqueous environments

Four fractions (A, B, C, and D) of humic acids (HAs) were separated based on the polarity from weak to strong. UV-vis absorption and Fourier transform infrared spectroscopy (FTIR) analysis show that the fractions C and Dpossessedmore aromatic C=C content. The influences of HAs and their fractions on the photolysis were investigated by the photodegradation of 2,4-D solutions under simulated solar light irradiation. The degradation rate of 2,4-D was found to decrease in the presence of bulk HAs or their fractions especially at high HAs concentration. The fractions of strong polarity C and D retarded the degradation rate more than the fractions of weak polarity A and B. This could be attributed to the different absorption intensity of the four HAs fractions in the order of D ? C > A > B, and the stronger π-π electron donor-acceptor interactions between the strong polar fractions and 2,4-D.     

One-step preparation of polyimide-inlaid amine-rich porous organic block copolymer for efficient removal of chlorophenols from aqueous solution

A novel polyimide-inlaid amine-rich porous organic block copolymer (PI-b-ARPOP) was prepared via one-step polymerization by using different molar ratios of melamine (MA)/terephthalaldehyde (TA)/pyromellitic dianhydride (PMDA), at molar ratios of 4/3/1, 4/2/2 and 4/1/3. The copolymer contained both aminal groups belonging to ARPOP and imide groups belonging to PI, and the bonding styles of the monomers and growth orientations of the polymeric chains were diversiform, forming an excellent porous structure. Notably, MA/TA/PMDA (4/2/2) had a surface area and pore volume of 487.27?m²/g and 1.169?cm³/g, respectively. The adsorption performance of the materials towards 2,4-dichlorophenol (2,4-DCP) in ultra-pure water was systematically studied. The pH value of 7 was optimal in aqueous solution. Na⁺ and Cl^? ions did not negatively affect the adsorption process, while humic acid (HA) slightly decreased the capacity. The equilibrium time was 40 sec, and the maximum adsorption capacity reached 282.49?mg/g at 298?K. The removal process was endothermic and spontaneous, and the copolymer could maintain its porous structure and consistent performance after regeneration by treatment with alkali. Moreover, to further assess the practical applicability of the material, the adsorption performance towards 2,4-DCP in river water was also investigated. This paper demonstrated that the PI-b-ARPOP can be an efficient and practical adsorbent to remove chlorophenols from aqueous solution.     

校正系数在工作曲线中应用

采用大肚移液管，将标准溶液配制成整数级别的贮备液、中间液、使用液时，利用工作曲线计算测定值需要引入校正系数，利用该方法可简化操作，减少误差提高实验准确度、精密度。     

卤代核苷植物油悬液一次注射法体内姐妹染色单体交换形成试验

本文介绍一种体内姐妹染色单体交换形成试验的新方法。将卤代核苷制成植物油悬液作皮下一次注射,当小鼠体内卤代核苷剂量达到500mg/kg时,即可获得非常满意的骨髓细胞姐妹染色单体分化着色效果。该法操作简便,无需特殊设备,卤代核苷用量亦较小。     

南海市废水重点污染源的特征与筛选方法

根据调查所得的南海市废水污染源，按照规范的评价标准和筛选原则，同时结合行业因素确定选标准，筛选出重点污染源１５６家，占全市调查工业企业数的３．４％，等标污染负荷量占调查负荷总量的８７．６％，重点污染源主要分布在陶瓷，铝型材，纺织印染，电镀，造纸和制革等６个行业，流域分布主要在西江及佛山水道。