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991.
992.
文章对海安县地表水环境存在的污染问题展开深入研究,并就相关问题针对性的提出了防治对策。 相似文献
993.
994.
采用孔径37 μm涤纶滤布制作膜组件,构成一体式自生动态膜生物反应器(SFDMBR),和以高岭土为预涂剂,组成预涂动态膜生物反应器( PDMBR),研究两者用于处理模拟生活污水的运行特性.结果表明,PDMBR抗膜污染效果比SFDMBR的好,PDMBR和SFDMBR的运行周期分别为13、11d,两者的膜通量基本稳定在28 L·m-2·h-1.当DO质量浓度大干0.5 mg·L-1时,DO对PDMBR和SFDMBR的COD去除几乎没有影响,对COD的击除率均在85%以上;PDMBR和SFDMBR的EPS浓度分别稳定在70、75 mg·L-1. 相似文献
995.
996.
997.
Shurong Wang Xinbao LiQianqian Yin Lingjun ZhuZhongyang Luo 《Catalysis communications》2011,12(13):1246-1250
Cu/SiO2 catalysts have been successfully prepared via urea hydrolysis method. The catalysts have been systematically characterized by X-ray diffraction, high-resolution transmission electron microscopy, N2-physisorption and H2 temperature-programmed reduction. The results demonstrated the presence of copper nanoparticles and their high dispersion on the SiO2 support. Catalysts with different copper loadings were prepared, and their performances in the hydrogenation of dimethyl oxalate to ethylene glycol were studied. A 100% conversion of dimethyl oxalate and maximum 98% selectivity of ethylene glycol were reached with 15.6 wt.% copper loading at 200 °C and 2 MPa. Furthermore, under the same reaction conditions, the catalyst can maintain the selectivity of 90% when the reduction temperature reduced from 350 °C to 200 °C. The high activity and selectivity over the catalyst may be ascribed to the homogenously distribution of copper nanoparticles on the large surface. 相似文献
998.
Yudan Wei Shuguo Zhang Shuangfeng Yin Chang Zhao Shenglian Luo Chak-tong Au 《Catalysis communications》2011,12(14):1333-1338
We report for the first time the synthesis of a novel solid superbase that was derived from lanthanum–magnesium composite oxide and KOH through thermal treatment. The as-prepared material shows base strength (H–) above 26.5 and is a high-efficiency catalyst for solvent-free Knoevenagel condensation at room temperature. The results of the present study open up a new dimension for the use of composite oxides as new support materials in the synthesis of superbases. 相似文献
999.
1000.
Rong Hua Zhang De An Shi Chi Pong Tsui Chak Yin Tang Sie Chin Tjong Robert Kwok Yiu Li 《Polymer Engineering and Science》2011,51(2):403-410
Compatibilized polypropylene (PP)/polyamide (PA6) blends with and without β nucleating agent (β‐NA) are prepared, and are designated as Blend‐0.3 and Blend‐0, respectively. The melting and crystallization characteristic of the blends crystallized under different cooling rates and different crystallization temperatures are studied. It is observed that high β‐PP content can be developed in Blend‐0.3 only at slow cooling rates (<5°C/min), whereas high α‐PP content is formed at fast cooling rates. Isothermal crystallization analysis of Blend‐0 indicates that PA6 is an effective NA for α‐PP in the lower temperature range, whereas the α‐nucleating effect disappears in the higher temperature range. Blend‐0.3 can, therefore, be viewed as a system containing both α‐ and β‐NAs, simultaneously. PA6 is competing with β‐NA in inducing PP crystallization. Under the normal injection of Blend‐0.3, the melt will be cooled through the higher temperature that favors the effectiveness of β‐NA rapidly because of the faster cooling rate. However, the α‐nucleation effect from PA6 predominate at the lower temperature. This explains the difficulty in obtaining high β‐PP content in Blend‐0.3 from injection molding. POLYM. ENG. SCI., 2011. © 2010 Society of Plastics Engineers 相似文献