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Yuanyuan Zhang Haiyan Lu Bing Wang Zhuo Zhang Xiaorong Lin Zhongzheng Chen Bin Li 《International Journal of Food Science & Technology》2015,50(6):1397-1404
Removal of imidacloprid and acetamiprid in tea infusions by microfiltration membrane using dead‐end model was investigated in the present study. The results showed that microfiltration significantly promoted the removal of both pesticides (P < 0.05) in tea infusions. Furthermore, the extent of removal was strongly influenced by the pore size of membrane, operational pressure and the concentrations of tea infusions. The initial concentration of imidacloprid and acetamiprid showed no significant effect on their removal rates. The maximum removal rates were 79.7% for imidacloprid and 81.9% acetamiprid. The changes in major chemical components of tea infusions after microfiltration were evaluated. The results indicated that microfiltration caused no considerable changes in total polyphenols and total free amino acids, and small but statistically significant losses (6.3–18.0%) of eight catechins and three methylxanthines when filtration volume reached to 200 mL. The present study validated the application of microfiltration as a potentially feasible and promising method for the removal of imidacloprid and acetamiprid residues from tea infusions. 相似文献
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Dongdong Ji Zheng Liu Bailing Jiang Xiaofei Luo 《International Journal of Hydrogen Energy》2021,46(27):13960-13970
The evaluation of cell's weatherability is of practical interest. To further improve the soluble lead flow battery's weatherability, physiochemical properties of electrolytes containing fluoborate, perchlorate, methanesulfonate and trifluoromethanesulfonate are investigated from ?60 to 50 °C. Activities of CF3SO3H and HClO4 are poor in trifluoromethanesulfonate and perchlorate solutions due to common anion effect. The solubility of lead salt can be improved by increasing temperature, but worsened by increasing acid's content. With the temperature increasing, the conductivity is enhanced, and the viscosity is lowered for four solutions. The same results have been found by increasing acid's content except for CF3SO3H. The high energy efficiency can be achieved for cells over ?40–0 °C using fluoborate and perchlorate solutions, 73.2% at ?40 °C and 78.1% at ?30 °C respectively. Over the temperature range of 20–50 °C, the cells with methanesulfonate and trifluoromethanesulfonate solutions have good performance, 77.4% and 73.7% at 50 °C respectively. 相似文献
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针对芦岭煤矿Ⅲ4采区8#、9#和10#煤层赋存情况、地质构造,结合现有矿井开拓系统及Ⅲ2、Ⅱ88采区巷道布置情况,按照采区巷道布置设计原则,提出3种采区巷道布置方案。方案一利用-590西皮大巷和-590轨道大巷新掘Ⅲ4采区上部车场,上山布置于F10断层东侧;方案二利用Ⅱ88采区下部车场及-590西皮大巷和-590轨道大巷布置Ⅲ4采区上部车场;方案三延长-900 m大巷至采区下部车场,从-590西皮大巷和-590轨道大巷中部新掘3条采区上山,并掘Ⅲ4采区石门总回风巷至Ⅱ88采区轨道巷,采区西翼布置区段平巷至井田西边界,东翼区段平巷布置至Ⅲ2采区边界。通过技术、经济比较,方案三具有初期投资小,运营费用低,经济效益最大,资源回收率高,巷道施工难度较低,开拓系统较为简单,投产工期最小的特点,最终决定采用方案三作为Ⅲ4采区巷道布置方案,保证工作面安全高效生产。 相似文献
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Huizhu Cai Bingbing Chen Xiao Zhang Yuchen Deng Dequan Xiao Ding Ma Chuan Shi 《Nano Research》2021,14(1):122-130
Over recent years,catalytic materials of Fe-N-C species have been recognized being active for oxygen reduction reaction(ORR).However,the identification of active site remains challenging as it generally involves a pyrolysis process and mixed components being obtained.Herein Fe3C/C and Fe2N/C samples were synthesized by temperature programmed reduction of Fe precursors in 15%CH4/H2and pure NH3,respectively.By acid leaching of Fe2N/C sample,only single sites of FeN4species were presented,providing an ideal model for identification of catalytic functions of the single sites of FeN4in ORR.A correlation was conducted between the concentration of FeⅡN4in low spin state by Mossbauer spectra and the kinetic current density at 0.8 V in alkaline media,and such a structure-performance correlation assures the catalytic roles of low spin FeⅡN4 species as highly active sites for the ORR. 相似文献
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