活性炭表面热氧化对其吸附二苯并噻吩性能影响

本文主要研究活性炭表面氧化对其吸附二苯并噻吩性能的影响。将活性炭在不同低温下氧化制得表面氧化活性炭，用静态吸附法进行了二苯并噻吩在初始及氧化活性炭上的吸附等温线，应用Langmuir方程对吸附等温线进行拟合，用漫反射红外谱（DRIFTS）表征活性炭表面含氧基团，用Boehm滴定测定活性炭表面官能团含量，讨论了活性炭表面化学性质对其吸附二苯并噻吩的影响。结果表明：活性炭表面酸性含氧基团对二苯并噻吩的吸附有重要影响，酸性含氧基团越多，其吸附量越大。低温气相氧化活性炭提高了活性炭表面酸性含氧基团，提高了其对二苯并噻吩的吸附。氧化温度越高，其表面含氧基团含量越多，其对二苯并噻吩的吸附量也越大。Langmuir吸附等温线可适用于描述二苯并噻吩在活性炭表面上的吸附。     

The Chemistry of Water Treatment Processes Involving Ozone,Hydrogen Peroxide and Ultraviolet Radiation

Advanced oxidation processes are defined as those which involve the generation of hydroxyl radicals in sufficient quantity to affect water purification. The theoretical and (practical yield of OH from O₃ at high pH, 0₃/H₂0₂, O₃/UV and H₂O₂/UV systems is reviewed. New data is presented which illustrates the importance of direct photolysis in the O₃/UV process, the effect of the H₂0₂:0₃ ratio in the O₃/H₂O₂ process, and the impact of the low extinction coefficient of H₂O₂ in the H₂0₂/UV process.     

聚电解质复合物研究现状及应用前景

介绍了聚电解质复全物的制务及研究方法，对影响聚电解质复合物形成及其结构的结果进行了阐述，简要介绍了其性能并对应用前景作了展望。     

Light-sensitive elastomers modified by 4-(N-dimethylmaleimido)-benzenesulphenyl chloride

New light-sensitive polymers were prepared by modification of four different elastomers with 4-(N-dimethylmaleimido)-benzenesulphenyl chloride (DMI-BSCI). Polydienes modified by DMI-BSCI form block copolymers. These polymers show a strong increase of the glass transition temperature T_g whereby the T_g increase of modified poly(octenamer) is much smaller. Higher modified polydienes have two T_g. Modified poly(octenamers) show a melting temperature dependence T_m on the content of trans double bonds which is characteristic of statistical copolymers. The ratio of rate constants with which trans- and cis-structures in poly(octenamer) are occupied by DMI-BSCI, is

$\text{k}{}_{\mathrm{trans}}\text{k}{}_{\mathrm{cis}}\text{= 0.34}$

     

Alkyd emulsions

Various aspects of alkyd emulsion technology have been investigated. The influence of alkyd oil length, acid value and hydroxyl number and type of surfactant used as emulsifier, on shear stability of alkyds emulsions have been studied. It was found that the acid value was the most important alkyd parameter, the stability increasing with increasing oil length. It is also shown that anionic surfactants give emulsions with small droplet sizes at lower concentrations than do nonionics. Polymerizable nonionic surfactants have been tested as emulsifiers and compared with conventional surfactants of the same hydrophilic lipophilic balance (HLB). It was found that surfactants capable of participating in the autoridative curing process give faster drying and improved film hardness compared with nonreactive surfactants. The distribution of driers between the alkyd phase and the water phase has been investigated. It was found that low pH and the use of hydrophilic anionic surfactants, such as sodium dodecyl sulphate, favour partitioning of cobalt into the aqueous phase which is unfavourable with respect to drying properties.     

炭纤维载体表面快速固着机理研究

采用炭纤维作为生物膜载体材料进行了污水处理实验,对炭纤维载体表面快速固着机理进行了研究。研究发现,炭纤维能够在水中快速且大量的固着活性污泥微生物。采用表面积测定仪、扫描电镜和XPS研究了炭纤维的表面特征。结果显示,炭纤维的表面形貌、表面官能团及表面活性碳原子是影响炭纤维表面微生物快速且大量固着的主要因素。     

基于AHP法的中低收入群体住房改善方案分析

通过对中低收入群体住房现状分析,构建了以相对最佳的住房改善方案为目标层;以住户对住房产品的满意、社会人均住房水平提高的效率高、参与建设各方获得良好经济效益3方面组成准则层;以经济适用房、廉租房、双限房、普通商品住房构成方案层的AHP模型。进行赋值计算后,得出当前发展经济适用房是相对最佳方案,发展廉租房次之,发展双限房第三,发展普通商品住房排名最后的结论。     

基于Ohde理论的群桩极限端阻力计算公式

为从理论上探讨群桩中桩-土-桩的相互作用,分析该作用对群桩端阻力形成机理的影响,以建立在压缩机理之上的适用于单桩端阻力分析的Ohde理论为基础,提出了无黏性土中群桩极限端阻力的计算模式,据此分别推导出了群桩中边桩和中桩的极限端阻力理论计算公式.该公式能够定量反映桩距、桩径、桩端的入土深度和桩端以下土层的物理力学性质等因素对极限端阻力的影响,计算得到的群桩极限端阻力随相对桩距(桩距与桩径之比)减小而增加的规律与模型试验的实测结果基本一致.     

试论营养教育的重点人群

营养教育是健康教育的重要组成部分,是方便、有效的营养干预方式,许多国家都极为重视。我国目前营养教育应当首先关注重点人群,即营养弱势群体和对膳食与营养具有影响力的人群。营养弱势群体主要包括儿童青少年、孕妇乳母、老年人、慢性病患者、社会弱势群体,他们或处在生长发育的关键时期、或处在特殊的生理时期,或是健康状况不良的人群,或是营养状况较差的群体;对膳食与营养具有影响力的人群主要包括家庭主妇、团体膳食制作及管理人员。营养教育应从这些重点人群入手,提高其膳食营养意识,普及基本营养知识,改善大众营养状况,提升生命质量。     

Formation of Bromate Ion Through a Radical Pathway in a Continuous Flow Reactor

The contribution of ozone and hydroxyl radical to the formation of bromate ion was investigated in a continuous flow reactor. Experiments were conducted under a wide range of ozone dose (0.7 ～ 3.8 mgL), pH (6.5 ～ 8.5), and t-butanol concentration (0 ～ 0.5 mM). The formation of bromate ion was found to depend on radical reaction pathway, because the amount of bromate ion formed increased with pH and decreased with t-butanol, a radical scavenger, even when dissolved ozone concentrations were almost the same. In fact, the amount of bromate ion formed was reduced by 90% in the presence of t-butanol. Furthermore, the formation of bromate ion occurred even when dissolved ozone was not significantly detected in the presence of organic matter (TOC of 1 mgCL). The second-order reaction rate constant of hydroxyl radical with bromide ion, k _HO,Br^? of 1.7 × 10⁹ (M^?1s^?1), was obtained on the assumption that the reactions of bromide ion and t-butanol with hydroxyl radical were competitive with each other in the presence of t-butanol and that the formation of bromate ion depended on the reaction of bromide ion with hydroxyl radical. Therefore, it is concluded that the reaction of bromide ion with hydroxyl radical dominated in the overall reaction from bromide ion to bromate ion in the continuous flow reactor.