Preparation of ultrafine Ce-based oxide nanoparticles and their catalytic performances for diesel soot combustion

The ultrafine Ce-based oxide nanoparticles with different element dopings （Zr, Y） were synthesized by the method of mi- cropores-diffused coprecipitation （MDC） using ammonia solution as the precipitation agent. The activities of the catalysts for soot oxidation were evaluated by the temperature-programmed oxidation （TPO） reaction. Ce-based oxides prepared in this study exhibited high catalytic activity for soot oxidation under tile condition of loose contact between soot particles and catalysts, and the catalytic ac- tivity ofultrafine Ce0.gZr0 iO2 nanoparticle for soot combustion was the highest, whose/＂10, Ts0 and Sco2m was 364, 442 ~C and 98.3%, respectively. All catalysts were systematically characterized by means of X-ray diffraction （XRD）, scanning electron microscopy （SEM）, transmission electron microscopy （TEM）, Brumauer-Emett-Teller （BET）, Fourier transform infrared spectroscopy （FT-IR） and UV-Vis diffuse reflectance spectroscopy （UV-Vis DRS）. It was indicated that the MDC method could prepare the ultrafine Ce-bascd oxide nanoparticles whose the crystal lattice were perfect, and the BET surface area and average crystal size of the ultrafine nanoparticles changed with the different element dopings （Zr, Y）. The H2-TPR measurements showed that the ultrafine Ce-based ox- ide nanoparticles with the doping-Zr cation could be favorable for improving the redox property of the catalysts.     

泡沫热态稳定的探索性试验研究

通过观察在热油面上泡沫状态和油品温度的变化,研究了泡沫热态稳定性及泡沫性能对油温的影响因素。试验证明,油品温度决定泡沫的热态稳定性,泡沫在油面上稳定停留的临界油温为125 ℃;当油温＞135 ℃时,随着油温增加,泡沫消失速度越来越快。油温降速与油品温度、泡沫析液速度、油品黏度有关,而与发泡倍数无关。油温越高、泡沫析液速度越快、油品黏度越低,油品降温速度越快。     

表面活性剂增敏微波等离子体炬原子发射光谱法测定聚烯烃树脂中铜

研究了在表面活性剂增敏作用下微波等离子体炬原子发射光谱法（MPT-AES）测定聚烯烃树脂中铜的新方法。对铜测定的仪器工作条件、酸效应及共存元素的影响进行了详细考察。实验结果表明,阳离子表面活性剂(CTMAB)对铜的测定有明显的增敏效果,可使铜的检出限由7.6 ng/mL下降为3.1 ng/mL,钒、钠、锰、铁、钛等元素的允许量由1倍提高到5倍以上。采用灰化法处理聚烯烃样品,通过工作曲线法测定聚乙烯和聚丙烯中铜的相对标准偏差分别为3.0 %和1.9 %,加标回收率分别为98 %～103 %和99 %～102 %。