Improvement of the antifouling characteristics in a bioreactor of polypropylene microporous membrane by the adsorption of Tween 20

Surface modification by physical adsorption of Tween 20 was accomplished on polypropylene microporous membranes (PPMMs). Attenuated total reflection-Fourier transform infrared spectroscopy (ATR/FT-IR) and scanning electron microscope (SEM) were used to characterize the chemical and morphological changes on the membrane surfaces. Water contact angles and relative pure water fluxes were measured. The data showed that the hydrophilic performance for the modified membranes increased with the increase in the adsorption amount of Tween 20 onto the surface or into the pores of polypropylene microporous membranes. To test the antifouling property of the membranes by the adsorption of Tween 20 in a membrane bioreactor (MBR), filtration for active sludge was performed using synthetic wastewater. With the help of the data of water fluxes and the FE-SEM photos of the modified PPMMs before or after operating in a MBR for about 12 d, the PPMMs with monolayer adsorption of Tween 20 showed higher remained flux and stronger antifouling ability than unmodified membrane and other modification membranes studied.     

流动注射在线氢化物发生—原子荧光光谱法测定环境水样中痕量无机汞和有机汞

提出了一种流动注射在线氢化物发生—原子荧光光谱法测定水样中痕量无机汞和有机汞的分析方法。以溴化剂作为有机汞的消解剂 ,在有、无溴化剂的存在下 ,采用流动注射在线氢化物发生—原子荧光光谱法分别测定总汞和无机汞 ,差减法求出有机汞的含量。方法操作简便快速 ,灵敏度高 ,干扰少 ,经加标回收实验验证 ,回收率达 95 %～ 10 5 %。     

微波消解-原子荧光法测定海洋沉积物中As的研究

研究了微波消解海洋沉积物中的As,在比较几种不同的酸消解体系后,得到适合海洋沉积物分析的酸消解体系.与传统的湿法消解比较,测试结果无显著性差异.微波消解具有快速高效、试剂用量少、空白值低、样品不易挥发等优点,已成为海洋沉积物样品前处理的有效手段.     

An investigation of methods for enriching trophoblast from maternal blood

Trophoblast deportation is known to occur in normal human pregnancy, but it is not yet clear whether these cells routinely enter the maternal peripheral circulation and are available as a source of fetal DNA for non-invasive prenatal diagnosis of genetic disorders. To resolve this issue requires an efficient method of enriching trophoblast from maternal blood combined with a means to confirm its identity. Five different techniques were tested on ten retroplacental blood samples to determine the most sensitive and operator-efficient method. Lysis of red cells alone gave the best recovery of trophoblast but had to be discounted, together with Ficoll density gradient centrifugation, due to the very low purity and the excessive time required. Fluorescence-activated cell sorting (FACS) of pre-enriched trophoblast resulted in the lowest recovery rate (8 per cent) despite a 3250-fold enrichment and a very high purity. Immunomagnetic beads (Dynabeads) coated with anti-CD 16 antibody proved to be the best method for the subsequent immunocytochemical characterization of deported trophoblast. However, IO beads coated with anti-CD45 antibody may be more useful for isolating trophoblast for prenatal diagnosis due to the high purity, enrichment (32-fold), and recovery rate (78 per cent) obtained with this method.     

知识产权法律体系在环保行业中的应用探讨

目前知识产权保护在我国建设创新型国家过程中已引起高度重视。结合环保领域知识产权领域的重大案例,通过对当前我国环保企业自身存在的问题以及加入WTO后给我国环保企业知识产权工作带来的影响进行了具体分析,从知识产权法律体系在环保行业中的应用的角度提出了解决现有问题的方法和思路。     

新型聚乙烯包装材料的可环境消纳性能研究

借助人工加速老化实验箱、户外暴晒架、自然土壤填埋坑等实验方法，采用力学性能测试、扫描电镜、热－红联用仪和乌氏粘度计等测试方法对所研制的新型聚乙烯（PE）塑料包装材料的可环境消纳性能进行探讨。实验结果表明，该材料自然暴露35d，羰基指数（CI）为45，光照10d后自然土壤掩埋，一年后CI为70，粘均分子质量Mη降到3678；生物降解性能达到3级；进行焚烧处理，尤其是在受光照后进行焚烧，可完全燃烧，不产生有害气体或粉尘。     

Aquafluor藻细胞活体分析法在三峡库区次级河流回水区Chla测定中的校准及应用

从三峡库区次级河流大宁河、小江、汤溪河及梅溪河139m回水区中段采集水样,经实验室培养后,用丙酮萃取分光光度法和Aquafluor藻细胞活体分析法测定Chla浓度.通过对Chla萃取值(y)和活体值(x)进行回归分析,得到其回归方程为y=4.15x 2.48,t检验显示回归方程具有线性.在库区次级河流139m回水区富营养化监测中,Chla模拟值与萃取值基本吻合,相对误差＜±7%,故可以采用Chla模拟值对水体富营养化程度进行评价.     

多环芳烃的同步荧光光谱技术及其对尿样中多环芳烃的鉴别

荧光光谱技术是一种灵敏度高和选择性强的光度分析方法,特别是对广泛存在于环境中的多环芳烃类化合物(PAHs)是一种有力的痕量分析手段,但在复杂混合样品的分析中却受到不同程度的限制。1971年Lloyd提出了同步激发的想法,接着Jobn,Lloyd和Dinh等分别发表了PAH类化合物同荧光光谱技术的研究报告,Dinh使用这     

论我国自然资源产权制度的改革

我国自然资源产权制度长期以来界定不清晰和不合理，造成自然资源配置的效率损失很大，本文根据许多实例和交易成本理论来说明５０年代中期以来我国自然资源的一些主要产权制度的利弊，并提出未来改革的一些设想。     

荧光光谱法研究丙酮与牛血清白蛋白的相互作用特征

在模拟动物体生理条件和不同温度下,用荧光光谱、三维荧光光谱、同步荧光光谱、紫外可见吸收光谱法等研究了丙酮(ACET)与牛血清白蛋白(BSA)的相互作用,证实了丙酮有很强的猝灭BSA荧光强度的能力.分别用Sterr-Volmer方程、Lineweaver-Burk双倒数方程和热力学方程等分析和处理试验数据,得到了它们相互作用的生成常数KLV(平均值为7.073×106L·mol-1)、热力学参数(△Hθ、△Gθ和△Sθ的平均值分别为-3.982kJ·mol-1、-26.51 kJ·mol-1和73.31J·K-1)和结合位点数(平均值为1.266)等.这为研究ACET对BSA构象的影响、ACET的毒理效应和生物学效应提供了重要信息.