The decomposition of copper anode slime heated by microwave energy in a sulfuric acid medium was investigated. Leaching experiments were carried out in a multi-mode cavity with microwave assistance. The leaching proce...The decomposition of copper anode slime heated by microwave energy in a sulfuric acid medium was investigated. Leaching experiments were carried out in a multi-mode cavity with microwave assistance. The leaching process parameters were optimized using response surface methodology（RSM）. Under the optimized conditions, the leaching efficiencies of copper and tellurium were 99.56% ± 0.16% and 98.68% ± 0.12%, respectively. Meanwhile, a conventional leaching experiment was performed in order to evaluate the influence of microwave radiation. The mechanism of microwave-assisted leaching of copper anode slime was also investigated. In the results, the microwave technology is demonstrated to have a great potential to improve the leaching efficiency and reduce the leaching time. The enhanced recoveries of copper and tellurium are believed to result from the presence of a temperature gradient due to the shallow microwave penetration depth and the superheating at the solid-liquid interface.展开更多
Polyacrylonitrile （PAN） based carbon fibers with different surface morphology were electrochemically treated in 3 wt% NH4HCO3 aqueous solution with current density up to 3.47 A/m 2 at room temperature, and surface s...Polyacrylonitrile （PAN） based carbon fibers with different surface morphology were electrochemically treated in 3 wt% NH4HCO3 aqueous solution with current density up to 3.47 A/m 2 at room temperature, and surface structures, surface morphology and residual mechanical properties were characterized. The crystallite size （La） of carbon fibers would be interrupted due to excessive electrochemical etching, while the crystallite spacing （d（002）） increased as increasing current density. The disordered structures on the surface of carbon fiber with rough surface increased at the initial oxidation stage and then removed by further electrochemical etching, which resulting in continuous increase of the extent of graphitization on the fiber surface. However, the electrochemical etching was beneficial to getting ordered morphology on the surface for carbon fiber with smooth surface, especially when the current density was lower than 1.77 A/m 2 . The tensile strength and tensile modulus could be improved by 17.27% and 5.75%, respectively, and was dependent of surface morphology. The decreasing density of carbon fibers probably resulted from the volume expansion of carbon fibers caused by the abundant oxygen functional groups intercalated between the adjacent graphite layers.展开更多
Silver nanorod arrays have been fabricated by alternat-ing current（AC） and pulsed direct current（DC） electrodeposition in porous anodic aluminum oxide（AAO） templates with controlled pore diameters of 19,38,and 6...Silver nanorod arrays have been fabricated by alternat-ing current（AC） and pulsed direct current（DC） electrodeposition in porous anodic aluminum oxide（AAO） templates with controlled pore diameters of 19,38,and 65 nm,respectively.The variation of their optical absorption properties with the incident angle and the nanorods length（corresponding to the electrodeposition time） has been investigated.Optical absorption spectra show that the posi-tion of longitudinal surface plasmon resonance（LSPR） peak has a small blueshift with the increase of incident angle of the excitation light.While the aspect ratio of the nanorods increases,the position of LSPR peak first redshifts and then blueshifts to a certain wave-length.Furthermore,the position of LSPR peak can be tuned,ranging from 550 nm to 900 nm,which makes it possible to cou-ple various wavelength of excitation source to assist radiative en-ergy transfer to the acceptor.展开更多
基金financially supported by the National Science and Technology Support Program of China during the 12th Five-Year Plan Period (No. 2012BAE06B05)the Fundamental Research Funds for the Central Universities of China (No. N130602004)
文摘The decomposition of copper anode slime heated by microwave energy in a sulfuric acid medium was investigated. Leaching experiments were carried out in a multi-mode cavity with microwave assistance. The leaching process parameters were optimized using response surface methodology（RSM）. Under the optimized conditions, the leaching efficiencies of copper and tellurium were 99.56% ± 0.16% and 98.68% ± 0.12%, respectively. Meanwhile, a conventional leaching experiment was performed in order to evaluate the influence of microwave radiation. The mechanism of microwave-assisted leaching of copper anode slime was also investigated. In the results, the microwave technology is demonstrated to have a great potential to improve the leaching efficiency and reduce the leaching time. The enhanced recoveries of copper and tellurium are believed to result from the presence of a temperature gradient due to the shallow microwave penetration depth and the superheating at the solid-liquid interface.
基金supported by the National Basic Research Program of China (No. 2011CB605602)
文摘Polyacrylonitrile （PAN） based carbon fibers with different surface morphology were electrochemically treated in 3 wt% NH4HCO3 aqueous solution with current density up to 3.47 A/m 2 at room temperature, and surface structures, surface morphology and residual mechanical properties were characterized. The crystallite size （La） of carbon fibers would be interrupted due to excessive electrochemical etching, while the crystallite spacing （d（002）） increased as increasing current density. The disordered structures on the surface of carbon fiber with rough surface increased at the initial oxidation stage and then removed by further electrochemical etching, which resulting in continuous increase of the extent of graphitization on the fiber surface. However, the electrochemical etching was beneficial to getting ordered morphology on the surface for carbon fiber with smooth surface, especially when the current density was lower than 1.77 A/m 2 . The tensile strength and tensile modulus could be improved by 17.27% and 5.75%, respectively, and was dependent of surface morphology. The decreasing density of carbon fibers probably resulted from the volume expansion of carbon fibers caused by the abundant oxygen functional groups intercalated between the adjacent graphite layers.
基金Supported by the National Natural Science Foundation of China (10874134)
文摘Silver nanorod arrays have been fabricated by alternat-ing current（AC） and pulsed direct current（DC） electrodeposition in porous anodic aluminum oxide（AAO） templates with controlled pore diameters of 19,38,and 65 nm,respectively.The variation of their optical absorption properties with the incident angle and the nanorods length（corresponding to the electrodeposition time） has been investigated.Optical absorption spectra show that the posi-tion of longitudinal surface plasmon resonance（LSPR） peak has a small blueshift with the increase of incident angle of the excitation light.While the aspect ratio of the nanorods increases,the position of LSPR peak first redshifts and then blueshifts to a certain wave-length.Furthermore,the position of LSPR peak can be tuned,ranging from 550 nm to 900 nm,which makes it possible to cou-ple various wavelength of excitation source to assist radiative en-ergy transfer to the acceptor.
