In order to minimize the pollution of ferrous sulfate, a by-product of titanium dioxide, and increase the yield of synthetic ester, the SO 2- <sub>4/Fe2O3 nanosolid superacid has been produced by chemical precip...In order to minimize the pollution of ferrous sulfate, a by-product of titanium dioxide, and increase the yield of synthetic ester, the SO 2- <sub>4/Fe2O3 nanosolid superacid has been produced by chemical precipitation and its micrographs was determined by SEM. The effect of preparation conditions of SO 2- <sub>4/Fe2O3 nanosolid superacid on catalysis synthesis butyl acetate and synthesis conditions of butyl acetate were studied.From experimental data,as compared with liquid acid, SO 2- <sub>4/Fe2O 3 nanosolid superacid showed higher catalytic performance in catalytic synthesis of butyl acetate,and the yield of butyl acetate was obviously increased in the same reaction time.展开更多
电磁波技术的广泛应用导致电磁干扰与污染日益严重,采取电磁屏蔽措施能够有效地防范这些危害。实验采用不同的方法分散镍纤维屏蔽介质,然后掺入到水泥材料中制得水泥基复合屏蔽材料,研究了屏蔽介质的分散方式、掺量、试样厚度对屏蔽性...电磁波技术的广泛应用导致电磁干扰与污染日益严重,采取电磁屏蔽措施能够有效地防范这些危害。实验采用不同的方法分散镍纤维屏蔽介质,然后掺入到水泥材料中制得水泥基复合屏蔽材料,研究了屏蔽介质的分散方式、掺量、试样厚度对屏蔽性能的影响;利用四探针测试仪、电子探针等手段表征了复合材料的电导率和屏蔽介质的分散均匀性。结果表明,镍纤维屏蔽介质的分散方式对屏蔽性能有较大的影响,其在水泥基材料中有一个最佳掺量值;当采用超声波分散的掺量φ镍纤维为5%、试样厚度为6 mm时,水泥基复合材料的电导率为2. 41×10^(-3)S/cm,在100 k Hz~1. 5 GHz频率范围内的平均屏蔽效能值约40 d B,其最小屏蔽效能值为36. 23 d B,最大达45. 74 dB。展开更多
文摘In order to minimize the pollution of ferrous sulfate, a by-product of titanium dioxide, and increase the yield of synthetic ester, the SO 2- <sub>4/Fe2O3 nanosolid superacid has been produced by chemical precipitation and its micrographs was determined by SEM. The effect of preparation conditions of SO 2- <sub>4/Fe2O3 nanosolid superacid on catalysis synthesis butyl acetate and synthesis conditions of butyl acetate were studied.From experimental data,as compared with liquid acid, SO 2- <sub>4/Fe2O 3 nanosolid superacid showed higher catalytic performance in catalytic synthesis of butyl acetate,and the yield of butyl acetate was obviously increased in the same reaction time.
文摘电磁波技术的广泛应用导致电磁干扰与污染日益严重,采取电磁屏蔽措施能够有效地防范这些危害。实验采用不同的方法分散镍纤维屏蔽介质,然后掺入到水泥材料中制得水泥基复合屏蔽材料,研究了屏蔽介质的分散方式、掺量、试样厚度对屏蔽性能的影响;利用四探针测试仪、电子探针等手段表征了复合材料的电导率和屏蔽介质的分散均匀性。结果表明,镍纤维屏蔽介质的分散方式对屏蔽性能有较大的影响,其在水泥基材料中有一个最佳掺量值;当采用超声波分散的掺量φ镍纤维为5%、试样厚度为6 mm时,水泥基复合材料的电导率为2. 41×10^(-3)S/cm,在100 k Hz~1. 5 GHz频率范围内的平均屏蔽效能值约40 d B,其最小屏蔽效能值为36. 23 d B,最大达45. 74 dB。