Magnetic Cu^0/Fe3O4 submicron composites were prepared using a hydrothermal method and used as heterogeneous catalysts for the activation of peroxymonosulfate（PMS） and the degradation of organic pollutants.The as-pr...Magnetic Cu^0/Fe3O4 submicron composites were prepared using a hydrothermal method and used as heterogeneous catalysts for the activation of peroxymonosulfate（PMS） and the degradation of organic pollutants.The as-prepared magnetic Cu^0/Fe3O4 submicron composites were composed of Cu^0 and Fe3O4 crystals and had an average size of approximately 220 nm.The Cu^0/Fe3O4 composites could efficiently catalyze the activation of PMS to generate singlet oxygen,and thus induced the rapid degradation of rhodamine B,methylene blue,orange Ⅱ,phenol and 4-chlorophenol.The use of0.1 g/L of the Cu^0/Fe3O4 composites induced the complete removal of rhodamine B（20 μmol/L） in15 min,methylene blue（20 μmol/L） in 5 min,orange Ⅱ（20 μmol/L） in 10 min,phenol（0.1mmol/L） in 30 min and 4-chlorophenol（0.1 mmol/L） in 15 min with an initial pH value of 7.0 and a PMS concentration of 0.5 mmol/L.The total organic carbon（TOC） removal higher than 85%for all of these five pollutants was obtained in 30 min when the PMS concentration was 2.5 mmol/L.The rate of degradation was considerably higher than that obtained with Cu^0 or Fe3O4 particles alone.The enhanced catalytic activity of the Cu^0/Fe3O4 composites in the activation of PMS was attributed to the synergistic effect of the Cu^0 and Fe3O4 crystals in the composites.Singlet oxygen was identified as the primary reactive oxygen species responsible for pollutant degradation by electron spin resonance and radical quenching experiments.A possible mechanism for the activation of PMS by Cu^0/Fe3O4 composites is proposed as electron transfer from the organic pollutants to PMS induces the activation of PMS to generate ^1O2,which induces the degradation of the organic pollutants.As a magnetic catalyst,the Cu^0/Fe3O4 composites were easily recovered by magnetic separation,and exhibited excellent stability over five successive degradation cycles.The present study provides a facile and green heterogeneous catalysis method for the oxidative removal of organic pollutants.展开更多
从一维细胞自动机模型入手,设计了一种求解二元离散优化问题的二元粒子群算法细胞自动机模型(BPSO-CA)。粒子从起始细胞出发,根据本身携带的信息并感知存储在细胞中的全局最优粒子位置的信息随机选择状态(0或1),从而实现复杂智能的"...从一维细胞自动机模型入手,设计了一种求解二元离散优化问题的二元粒子群算法细胞自动机模型(BPSO-CA)。粒子从起始细胞出发,根据本身携带的信息并感知存储在细胞中的全局最优粒子位置的信息随机选择状态(0或1),从而实现复杂智能的"涌现"。然后将其用来求解多维0/1背包问题,同时引入贪心算法对不符合约束条件的非法个体进行修正。通过对Zuse Institute Berlin公布的测试集进行实验,表明该模型能在多项式时间内完成求解过程,且实验结果优于测试集记录的结果。展开更多
基金supported by the National Natural Science Foundation of China (21377169, 21507168)the Fundamental Research Funds for the Central Universities (CZW15078)the Natural Science Foundation of Hubei Province of China (2014CFC1119, 2015CFB505)~~
文摘Magnetic Cu^0/Fe3O4 submicron composites were prepared using a hydrothermal method and used as heterogeneous catalysts for the activation of peroxymonosulfate（PMS） and the degradation of organic pollutants.The as-prepared magnetic Cu^0/Fe3O4 submicron composites were composed of Cu^0 and Fe3O4 crystals and had an average size of approximately 220 nm.The Cu^0/Fe3O4 composites could efficiently catalyze the activation of PMS to generate singlet oxygen,and thus induced the rapid degradation of rhodamine B,methylene blue,orange Ⅱ,phenol and 4-chlorophenol.The use of0.1 g/L of the Cu^0/Fe3O4 composites induced the complete removal of rhodamine B（20 μmol/L） in15 min,methylene blue（20 μmol/L） in 5 min,orange Ⅱ（20 μmol/L） in 10 min,phenol（0.1mmol/L） in 30 min and 4-chlorophenol（0.1 mmol/L） in 15 min with an initial pH value of 7.0 and a PMS concentration of 0.5 mmol/L.The total organic carbon（TOC） removal higher than 85%for all of these five pollutants was obtained in 30 min when the PMS concentration was 2.5 mmol/L.The rate of degradation was considerably higher than that obtained with Cu^0 or Fe3O4 particles alone.The enhanced catalytic activity of the Cu^0/Fe3O4 composites in the activation of PMS was attributed to the synergistic effect of the Cu^0 and Fe3O4 crystals in the composites.Singlet oxygen was identified as the primary reactive oxygen species responsible for pollutant degradation by electron spin resonance and radical quenching experiments.A possible mechanism for the activation of PMS by Cu^0/Fe3O4 composites is proposed as electron transfer from the organic pollutants to PMS induces the activation of PMS to generate ^1O2,which induces the degradation of the organic pollutants.As a magnetic catalyst,the Cu^0/Fe3O4 composites were easily recovered by magnetic separation,and exhibited excellent stability over five successive degradation cycles.The present study provides a facile and green heterogeneous catalysis method for the oxidative removal of organic pollutants.
文摘从一维细胞自动机模型入手,设计了一种求解二元离散优化问题的二元粒子群算法细胞自动机模型(BPSO-CA)。粒子从起始细胞出发,根据本身携带的信息并感知存储在细胞中的全局最优粒子位置的信息随机选择状态(0或1),从而实现复杂智能的"涌现"。然后将其用来求解多维0/1背包问题,同时引入贪心算法对不符合约束条件的非法个体进行修正。通过对Zuse Institute Berlin公布的测试集进行实验,表明该模型能在多项式时间内完成求解过程,且实验结果优于测试集记录的结果。
基金国家自然科学基金(the National Natural Science Foundation of China under Grant No.70471065)上海市高校选拔培养优秀青年教师科研专项基金(Shanghai Scientific Special Funds For Cultivation and Selection of Excellent Young Teaching Staffs of Higher Education under Grant No.21012)+1 种基金上海市教委科技发展基金(Science and Technology Development Funds of Shanghai Education Commission under Grant No.05EZ31)上海市重点学科建设项目(Shanghai Leading Academic Discipline Project under Grant No.T0502)
