丙烯酸树脂漆渣共混改性PVC泡沫复合材料性能研究

利用回收热塑性丙烯酸树脂漆渣共混改性聚氯乙烯(PVC)发泡体系,并通过热压法制备泡沫复合材料,研究了树脂漆渣添加量对体系剪切黏度及发泡产品泡孔微观形貌、表观密度、力学和耐热性能的影响。结果表明:丙烯酸树脂漆渣的加入可增加PVC分子链间相互作用力,提高PVC发泡体系的剪切黏度,从而调控熔体强度,得到泡孔结构细密均匀的泡沫复合材料;最佳树脂漆渣添加量为10%,PVC发泡体系的剪切黏度由2 726.1 Pa·s升至9 029.4 Pa·s,制备的PVC泡沫复合材料表观密度由0.63 g/cm ³降至0.49 g/cm ³,弯曲强度和冲击强度分别由13.6 MPa和4.7 kJ/m ²升至18.2 MPa和8.9 kJ/m ²,玻璃化转变温度(T_g)由72 ℃升至75 ℃。     

Community attitudes to cystic fibrosis carrier testing in England: A pilot study

Inexpensive and accurate carrier testing for cystic fibrosis (CF) will be possible in the near future. There are no existing studies on the attitudes of English persons in the community to carrier testing for CF or any other recessive disorder. We have conducted a trial study of 166 persons at two schools, two doctors' surgeries, and a family planning clinic. Only a minority had clear pre-existing knowledge of cystic fibrosis and its genetic nature. However, over 80 per cent of those questioned expressed interest in knowing their carrier status. Although it is well known that uptake can only be assessed when a service is in place, and while further studies are required to confirm that testing will be of interest to couples of reproductive age with no previous knowledge of CF, the data strongly suggest that there will be interest in communitywide testing for CF carrier status when such a test becomes available in the United Kingdom.     

微波技术在分析检验与污染治理中的应用

综述了微波技术的特点及其近几年在分析检验与污染治理中应用的进展情况，包括消解样品、脱附、显色、干燥、萃取、污水处理、废气处理、固体废弃物处理等方面；与传统技术比较，微波技术有许多优点，其在现代工业和科学研究领域里极具推广价值和应用前景。     

Immobilization of activated sludge using improved polyvinyl alcohol （PVA） gel

The microbial immobilization method using polyvinyl alcohol(PVA)gel as an immobilizing material was improved and used for entrapment of activated sludge.The oxygen uptake rate(OUR)was used to characterize the biological activity of immobilized activated sludge.Three kinds of PVA-immobilized particles of activated sludge,that is,PVA-boric acid beads,PVA-sodium nitrate beads and PVA-orthophosphate beads were prepared,and their biological activity was compared by measuring the OUR value.The bioactivity of both autotrophic and heterotrophic microorganisms of activated sludge was determined using different synthetic wastewater media (containing 250 mg/L COD and 25 mg/L NH_4~ -N).The experimental results showed that the bioactivity and stability of the three kinds of immobilized activated sludge was greatly improved after activation.With respect of the bioactivity and the mechanical stability,the PVA-orthophosphate method may be a promising and economical technique for microbial immobilization.     

湿热环境对PMMA混杂纳米复合材料性能的影响

目的研究湿热环境对聚甲基丙烯酸甲酯(PMMA)混杂纳米复合材料性能的影响。方法利用制备的水包油型杂化乳液稳定剂EMI/GO/CNTs稳定以甲基丙烯酸甲酯(MMA)为油相的水包油型Pickering乳液,用偶氮二异丁氰(AIBN)为引发剂,引发Pickering乳液进行悬浮聚合,聚合产物为PMMA混杂纳米复合材料。将PMMA混杂纳米复合材料模压成型,分别在室温及50℃下进行水浸吸湿实验。采用光学显微镜对Pickering乳液液滴形貌进行分析,通过复合材料的质量变化、动态力学分析测试、导电性测试,对复合材料的吸湿率、玻璃化转变温度及导电性变化进行分析。结果用EMI/GO/CNTs稳定的以MMA为油相的水包油型Pickering乳液具有良好的稳定性,乳液液滴的尺寸分布范围较窄,分布较均匀。复合材料的吸水量随时间增加逐渐增大,达到吸湿平衡状态后,吸湿率基本不变。不同温度下水浸复合材料的吸湿速度和平衡吸湿率不同,50℃水浸比25℃水浸的复合材料的吸湿速度快且平衡吸湿率大。湿热后复合材料的玻璃化转变温度基本不变。复合材料经湿热环境处理后电导率升高1~2个数量级。结论利用制备的杂化乳液稳定剂制备出Pickering乳液并进行悬浮聚合、模压成型,制备出PMMA复合材料。经水浸湿热处理后的复合材料,其吸湿率和电导率均有一定变化,玻璃化转变温度基本不变。     

检测质量监督检查结果的几点启示

分析了监督管理部门近2年对386个检测机构的监督检查结果,揭示了检测工作质量管理的薄弱环节,分别是记录管理、质量体系的建立、检测报告、设备检定/校准及管理,总结归纳了主要问题的表现形式,提出了提高检测质量的建议,以利于检测机构更有效开展相关工作。     

涂层的AC-DC-AC电化学加速试验评价方法及研究状况

为了能快速促进涂层失效,准确评价涂层耐蚀性能,介绍了AC-DC-AC电化学加速试验方法这种非传统的加速试验方法,回顾了AC-DC-AC电化学加速试验方法的研究历史和现状,分析了它的理论基础,讨论了该方法能加速涂层失效的机理以及试验方法中的三个关键过程,并在此基础上,对AC-DC-AC电化学加速试验方法的研究前景进行了展望。