A novel adsorbent named magnetic humic acid/chitosan composite(M-HA/Cs) was synthesized by decorating humic acid/chitosan composites with Fe_3O_4 nanoparticles. The adsorption capacity of M-HA/Cs was 1.5 times that of...A novel adsorbent named magnetic humic acid/chitosan composite(M-HA/Cs) was synthesized by decorating humic acid/chitosan composites with Fe_3O_4 nanoparticles. The adsorption capacity of M-HA/Cs was 1.5 times that of MCs. The effects of solution p H, initial concentration of Pb(Ⅱ) ions and adsorption temperature on Pb(Ⅱ) removal were examined in a batch system and further optimized using Box-Behnken analysis. The recommended optimum conditions are initial Pb(Ⅱ) concentration of 139.90 mg/L, initial pH of 4.98, and temperature of 43.97 oC. The adsorption processes could be well described by pseudo-second-order and Elovich models. Isotherm studies reveal that the adsorption process follows Sips and Temkin models. The thermodynamic study indicats that the adsorption process is spontaneous and exothermic. The potential mechanism of Pb(Ⅱ) on M-HA/Cs at pH 5 may be surface electrostatic attraction, coordination and hydrogen bonding.展开更多
In order to solve the problem of weak power performance of vehicle equipped with continuously variable transmission(CVT) system working under transient operating conditions, a new CVT equipped with planetary gear mech...In order to solve the problem of weak power performance of vehicle equipped with continuously variable transmission(CVT) system working under transient operating conditions, a new CVT equipped with planetary gear mechanism and flywheel was researched, a design method of transmission parameter optimization was proposed, and the comprehensive matching control strategy was established for the new transmission system. Fuzzy controllers for throttle opening and CVT speed ratio were designed, and power performance and fuel economy of both vehicles respectively equipped with conventional CVT system and new transmission system wrere compared and analyzed by simulation. The results show that power performance and fuel economy of the vehicle equipped with new transmission system are better than that equipped with conventional CVT, thus the rationality of the parameter design method and control algorithm are verified.展开更多
基金Projects(41271332,51478470)supported by the National Natural Science Foundation of China
文摘A novel adsorbent named magnetic humic acid/chitosan composite(M-HA/Cs) was synthesized by decorating humic acid/chitosan composites with Fe_3O_4 nanoparticles. The adsorption capacity of M-HA/Cs was 1.5 times that of MCs. The effects of solution p H, initial concentration of Pb(Ⅱ) ions and adsorption temperature on Pb(Ⅱ) removal were examined in a batch system and further optimized using Box-Behnken analysis. The recommended optimum conditions are initial Pb(Ⅱ) concentration of 139.90 mg/L, initial pH of 4.98, and temperature of 43.97 oC. The adsorption processes could be well described by pseudo-second-order and Elovich models. Isotherm studies reveal that the adsorption process follows Sips and Temkin models. The thermodynamic study indicats that the adsorption process is spontaneous and exothermic. The potential mechanism of Pb(Ⅱ) on M-HA/Cs at pH 5 may be surface electrostatic attraction, coordination and hydrogen bonding.
基金Project(2011BA3019)supported by the Chongqing Natural Science Foundation,China
文摘In order to solve the problem of weak power performance of vehicle equipped with continuously variable transmission(CVT) system working under transient operating conditions, a new CVT equipped with planetary gear mechanism and flywheel was researched, a design method of transmission parameter optimization was proposed, and the comprehensive matching control strategy was established for the new transmission system. Fuzzy controllers for throttle opening and CVT speed ratio were designed, and power performance and fuel economy of both vehicles respectively equipped with conventional CVT system and new transmission system wrere compared and analyzed by simulation. The results show that power performance and fuel economy of the vehicle equipped with new transmission system are better than that equipped with conventional CVT, thus the rationality of the parameter design method and control algorithm are verified.
