甲基紫褪色光度法测定电镀废水中微量的铜

研究了在HNO3介质 ,95℃沸水浴中 ,Cu2 + 催化过氧化氢氧化甲基紫褪色反应的适宜条件及影响因素 ,据此建立了动力学褪色光度法测定微量Cu2 + 的新方法。方法的线性范围为 0～ 12 0 μg L ,表观摩尔吸光系数为 2 88× 10 5L mol·cm ,最大吸收波长为 5 80nm ,方法的检出限为 1 79× 10 - 1 0 μg L。该法应用于电镀废水中铜的测定 ,结果令人满意。     

聚合氯化铝铁检验方法研究

聚合氯化铝铁是一种新型净水剂,它结合铝系和铁系净水剂的优点,有助于减少水中铅含量。利用《水处理剂聚合氯化铅(GB15892-1995)》和《净化剂聚合氯化铁(GB14591-93)》的方法,对聚合氯化铅铁主要技术指标的检验做了探索。经反复实验,取得了较好的效果。     

高浓度甲基橙溶液的低压湿式催化氧化处理

以高浓度甲基橙溶液模拟偶氮染料废水,采用低压湿式催化氧化法(LPWCO)进行处理,考察了H2O2投量、温度、FeSO4投量、硫酸浓度、甲基橙浓度等因素对甲基橙脱色率的影响。结果表明,LPWCO法能有效地使高浓度(大于400mg/L)甲基橙溶液脱色,脱色率大于95%,而H2O2投量不到Fenton法的5%。     

甲基橙褪色法测定生活饮用水中余氯的探讨

在酸性介质中,余氯使甲基橙褪色,最大吸收波长510 nm,摩尔吸光系数A510=5.41×10-3 l/mol·cm,余氯质量浓度在(0.05～1.00) mg/l范围内遵守朗伯--比耳定律.对甲基橙溶液的加入量、样品溶液褪色后其吸光值的稳定性等方面作了条件试验,同时与邻联甲苯胺(OT)比色法和N,N-二乙基对苯二胺(DPD)分光光度法进行比对测定,结果表明三种方法测定结果基本一致.     

瓷砖釉面TiO2薄层对甲基橙的光催化降解

采用溶胶-凝胶法，在瓷砖釉面上制备了良好光催化活性TiO2薄层材料，研究结果表明瓷砖釉面TiO2薄层材料对甲基橙的光催化反应遵循一级动力学规律，光催化降解率与液层厚度符合指数关系。在太阳光照射下，釉面瓷砖TiO2薄层材料能对甲基橙有效地降解。     

Starch, Poly(lactic acid), and Poly(vinyl alcohol) Blends

Research on biodegradable materials has been stimulated due to concern regarding the persistence of plastic wastes. Blending starch with poly(lactic acid) (PLA) is one of the most promising efforts because starch is an abundant and cheap biopolymer and PLA is biodegradable with good mechanical properties. Poly(vinyl alcohol) (PVOH) contains unhydrolytic residual groups of poly(vinyl acetate) and also has good compatibility with starch. It was added to a starch and PLA blend (50:50, w/w) to enhance compatibility and improve mechanical properties. PVOH (M_W 6,000) at 10%, 20%, 30%, 40%, 50% (by weight) based on the total weight of starch and PLA, and 30% PVOH at various molecular weights (M_W 6,000, 25,000, 78,000, and 125,000 dalton) were added to starch/PLA blends. PVOH interacted with starch. At proportions greater than 30%, PVOH form a continuous phase with starch. Tensile strength of the starch/PLA blends increased as PVOH concentration increased up to 40% and decreased as PVOH molecular weight increased. The increasing molecular weight of PVOH slightly affected water absorption, but increasing PVOH concentration to 40% or 50% increased water absorption. Effects of moisture content on the starch/PLA/PVOH blend also were explored. The blend containing gelatinized starch had higher tensile strength. However, gelatinized starch also resulted in increased water absorption.     

Enhanced production of poly(3-hydroxybutyrate) by filamentation-suppressed recombinantEscherichia coli in a defined medium

Fed-batch cultures of recombinantEscherichia coli strains were carried out for the production of poly(3-hydroxybutyric acid) (PHB) in a chemically defined medium. TheE. coli strains used were XL1-Blue, harboring pSYL105, a stable high-copy number plasmid containing theAlcaligenes eutrophus polyhydroxyalkanoate (PHA) genes, and XL1-Blue, harboring pSYL107, which is pSYL105 containing theE. coli ftsZ gene to suppress filamentation. With XL1-Blue(pSYL105) the final cell mass and PHB concentration obtained in 62 h were 102 and 22.5 g/L, respectively. Fed-batch culture of XL1-Blue(pSYL107) under identical conditions resulted in a final cell mass and PHB concentration of 127.5 and 48.2 g/L, respectively. The PHB contents obtained with XL1-Blue(pSYL105) and XL1-Blue(pSYL107) were 22.1 and 37.8%, respectively. Therefore, PHB was more efficiently produced in a defined medium by employing filamentation-suppressed recombinantE. coli.     

Thermal and mechanical properties of poly(lactic Acid) and poly(ethylene/butylene Succinate) blends

In this study, blends of poly (lactic acid) (PLA) with poly(ethylene/butylene succinate) (Bionolle) have been investigated for their thermal and mechanical properties as a function of the concentration of Bionolle. Differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), and tensile tests were used to characterize the blends. From the results of the DMA and DSC, it was found that this blend system was not miscible within the compositions studied. DSC results showed that adding Bionolle aids in crystallization of PLA. It was observed that increasing the Bionolle concentration led to a slight increase in the strain-at-break of the blends but a decrease in the Young’s modulus and ultimate tensile strength. Biaxially oriented films showed an increase in tensile strength, modulus, and strain-at-break.     

防辐射有机玻璃板材的抗辐射性能

系统研究了含铅有机玻璃、含钡有机玻璃、含硼有机玻璃和普通有机玻璃的ｘ、γ射线和中子射线防护性能及其耐６０Ｃγ射线辐照稳定性。结果表明，含铅有机玻璃板材具有良好的ｘ射线、反应堆热柱γ射线屏蔽性能；合硼有机玻璃板材具有良好的热中子屏蔽性能；含钡有机玻璃板材的褪化裂变谱中子辐射屏蔽性能良好；含钡有机玻璃和普通有机玻璃可耐１０５～１０６Ｇｙ的６０Ｃｏｙ射线辐照；含铅有机玻璃板材耐６０Ｃｏｙ射线照射能力小于１０５Ｇｙ。     

甲基汞对大鼠脑一氧化氮合酶,丙二醛和即刻早期基因的影响

为了寻找甲基汞神经毒性检测和评价效应指标以及探讨甲基汞神经毒性分子机制,对大鼠进行氯化甲基汞(MMC)急性暴露(对照组为0.9％生理盐水、暴露组浓度为0.05mg/kg),20min后对大鼠进行生理生化指标和即早基因的检测,大鼠大脑中枢神经系统的神经递质一氧化氮合酶活力采用一氧化氮合酶(NOS)测定试剂盒检测;自由基脂质过氧化产物丙二醛含量采用硫代巴比妥酸(TBA)比色法检测;即刻早期基因c-fos表达的变化采用免疫组化方法检测。结果表明,在暴露氯化甲基汞(MMC)20min后,大鼠大脑中枢神经系统的一氧化氮合酶活力、自由基脂质过氧化产物丙二醛含量以及即刻早期基因(IEG)c-fos蛋白阳性表达数量都有提高。但其中一氧化氮合酶活力及自由基脂质过氧化产物丙二醛含量同对照组相比没有显著性差异;而即刻早期基因c-fos的阳性表达同对照组相比有极显著性差异(P<0.01)。据此可以推测,即刻早期基因能作为甲基汞神经毒性检测和评价效应指标,一氧化氮合酶、丙二醛和即刻早期基因在甲基汞神经毒性过程中具有重要作用。