Numerical simulations of gas–liquid two-phase flow and alumina transport process in an aluminum reduction cell were conducted to investigate the effects of anode configurations on the bath flow, gas volume fraction a...Numerical simulations of gas–liquid two-phase flow and alumina transport process in an aluminum reduction cell were conducted to investigate the effects of anode configurations on the bath flow, gas volume fraction and alumina content distributions. An Euler–Euler two-fluid model was employed coupled with a species transport equation for alumina content. Three different anode configurations such as anode without a slot, anode with a longitudinal slot and anode with a transversal slot were studied in the simulation. The simulation results clearly show that the slots can reduce the bath velocity and promote the releasing of the anode gas, but can not contribute to the uniformity of the alumina content. Comparisons of the effects between the longitudinal and transversal slots indicate that the longitudinal slot is better in terms of gas–liquid flow but is disadvantageous for alumina mixing and transport process due to a decrease of anode gas under the anode bottom surface. It is demonstrated from the simulations that the mixing and transfer characteristics of alumina are controlled to great extent by the anode gas forces while the electromagnetic forces(EMFs) play the second role.展开更多
In order to join alumina ceramic to 5A05 aluminum alloy and obtain the excellent airtightness of joints whose maximum service temperature is 623 K, transient liquid phase （TLP） bonding technique was ,investigated us...In order to join alumina ceramic to 5A05 aluminum alloy and obtain the excellent airtightness of joints whose maximum service temperature is 623 K, transient liquid phase （TLP） bonding technique was ,investigated using Ag-Cu-Ti alloy as interlayer. The wetting experimental results confirm that Ti can react with alumina ceramic at 833 K by adding 2 wt.% Ti in Sn. But during bonding alumina ceramic and 5A05 aluminum alloy with Ag-Cu-Ti interlayer at 833 K, Ti preferentially reacts with Al and there is no reaction layer on alumina ceramic/Ag-Cu-Ti interface, which finally results in a poorly airtight joint.展开更多
A new process for removing the pollutants in aqueous solution-activated alumina bed in pulsed high-voltage electric field was investigated for the removal of phenol under different conditions. The experimental results...A new process for removing the pollutants in aqueous solution-activated alumina bed in pulsed high-voltage electric field was investigated for the removal of phenol under different conditions. The experimental results indicated the increase in removal rate with increasing applied voltage, increasing pH value of the solution, aeration, and adding Fe^2＋. The removal rate of phenol could reach 72.1% when air aeration flow rate was 1200 ml/min, and 88.2% when 0.05 mmol/L Fe^2＋ was added into the solution under the conditions of applied voltage 25 kV, initial phenol concentration of 5 mg/L, and initial pH value 5.5. The addition of sodium carbonate reduced the phenol removal rate. In the pulsed high-voltage electric field, local discharge occurred at the surface of activated alumina, which promoted phenol degradation in the thin water film. At the same time, the space-time distribution of gas-liquid phases was more uniform and the contact areas of the activated species generated from the discharge and the pollutant molecules were much wider due to the effect of the activated alumina bed. The synthetical effects of the pulsed high-voltage electric field and the activated alumina particles accelerated phenol degradation.展开更多
采用铝液通氢的方法模拟木条裂解产物氢、H2O（汽）与铝液作用过程,利用化学分析、氢分析、扫描电子显微镜（SEM）以及分子动力学方法,研究了氢及通氢时带入的水与铝液反应过程,模拟计算氢在铝液中的扩散方式以及影响扩散的关键环节。...采用铝液通氢的方法模拟木条裂解产物氢、H2O（汽）与铝液作用过程,利用化学分析、氢分析、扫描电子显微镜（SEM）以及分子动力学方法,研究了氢及通氢时带入的水与铝液反应过程,模拟计算氢在铝液中的扩散方式以及影响扩散的关键环节。研究氢、氧化铝夹杂在铝样中的形貌与分布规律,从微观机制上揭示氢对电解铝液的传质规律。结果表明:熄效应使铝液氢含量增加,实验铝液氢含量达到1.266 m L/100 g,铝液中的Al3Ti、Al2O3共同吸附铝液中的氢形成AlTiOH团簇,寄生于氧化铝夹杂表面的氢随氧化铝夹杂悬浮于铝液中,是铝液中氢含量明显升高的原因。展开更多
目的建立脑立清制剂中水麦冬酸成分的检测方法。方法样品经萃取富集后,利用超高效液相色谱-三重四极杆质谱(UPLC-MS/MS),以水麦冬酸为指标成分,对脑立清制剂中常见掺伪虎掌南星情况进行监控。采用Waters ACQUITY UPLC HSS T3 C 18(2.1 m...目的建立脑立清制剂中水麦冬酸成分的检测方法。方法样品经萃取富集后,利用超高效液相色谱-三重四极杆质谱(UPLC-MS/MS),以水麦冬酸为指标成分,对脑立清制剂中常见掺伪虎掌南星情况进行监控。采用Waters ACQUITY UPLC HSS T3 C 18(2.1 mm×100 mm,1.8μm)色谱柱,以乙腈-0.1%甲酸溶液为流动相,梯度洗脱,体积流量0.2 mL·min^(-1);柱温30℃,进样量2μL;质谱条件采用ESI-多反应监测(MRM)模式扫描,选择m/z 187.0→143.3和m/z 187.0→98.9作为检测离子对。结果以所建立的方法对88批次脑立清制剂进行检测,结果5个厂家的15批样品检查出水麦冬酸成分。结论所建立的方法准确可靠,专属性强,可用于脑立清制剂中的水麦冬酸成分的检查;同时也为其他含半夏制剂中掺伪虎掌南星的监控提供参考。展开更多
基金Project(2010AA065201)supported by the High Technology Research and Development Program of ChinaProject(2013zzts038)supported by the Fundamental Research Funds for the Central Universities of ChinaProject(ZB2011CBBCe1)supported by the Major Program for Aluminum Corporation of China Limited,China
文摘Numerical simulations of gas–liquid two-phase flow and alumina transport process in an aluminum reduction cell were conducted to investigate the effects of anode configurations on the bath flow, gas volume fraction and alumina content distributions. An Euler–Euler two-fluid model was employed coupled with a species transport equation for alumina content. Three different anode configurations such as anode without a slot, anode with a longitudinal slot and anode with a transversal slot were studied in the simulation. The simulation results clearly show that the slots can reduce the bath velocity and promote the releasing of the anode gas, but can not contribute to the uniformity of the alumina content. Comparisons of the effects between the longitudinal and transversal slots indicate that the longitudinal slot is better in terms of gas–liquid flow but is disadvantageous for alumina mixing and transport process due to a decrease of anode gas under the anode bottom surface. It is demonstrated from the simulations that the mixing and transfer characteristics of alumina are controlled to great extent by the anode gas forces while the electromagnetic forces(EMFs) play the second role.
基金This work was supported by the National Natural Science Foundation of China （ No. 50705022）.
文摘In order to join alumina ceramic to 5A05 aluminum alloy and obtain the excellent airtightness of joints whose maximum service temperature is 623 K, transient liquid phase （TLP） bonding technique was ,investigated using Ag-Cu-Ti alloy as interlayer. The wetting experimental results confirm that Ti can react with alumina ceramic at 833 K by adding 2 wt.% Ti in Sn. But during bonding alumina ceramic and 5A05 aluminum alloy with Ag-Cu-Ti interlayer at 833 K, Ti preferentially reacts with Al and there is no reaction layer on alumina ceramic/Ag-Cu-Ti interface, which finally results in a poorly airtight joint.
基金Project supported by the Technology Innovation Project of University (No. 705013)
文摘A new process for removing the pollutants in aqueous solution-activated alumina bed in pulsed high-voltage electric field was investigated for the removal of phenol under different conditions. The experimental results indicated the increase in removal rate with increasing applied voltage, increasing pH value of the solution, aeration, and adding Fe^2＋. The removal rate of phenol could reach 72.1% when air aeration flow rate was 1200 ml/min, and 88.2% when 0.05 mmol/L Fe^2＋ was added into the solution under the conditions of applied voltage 25 kV, initial phenol concentration of 5 mg/L, and initial pH value 5.5. The addition of sodium carbonate reduced the phenol removal rate. In the pulsed high-voltage electric field, local discharge occurred at the surface of activated alumina, which promoted phenol degradation in the thin water film. At the same time, the space-time distribution of gas-liquid phases was more uniform and the contact areas of the activated species generated from the discharge and the pollutant molecules were much wider due to the effect of the activated alumina bed. The synthetical effects of the pulsed high-voltage electric field and the activated alumina particles accelerated phenol degradation.
文摘采用铝液通氢的方法模拟木条裂解产物氢、H2O（汽）与铝液作用过程,利用化学分析、氢分析、扫描电子显微镜（SEM）以及分子动力学方法,研究了氢及通氢时带入的水与铝液反应过程,模拟计算氢在铝液中的扩散方式以及影响扩散的关键环节。研究氢、氧化铝夹杂在铝样中的形貌与分布规律,从微观机制上揭示氢对电解铝液的传质规律。结果表明:熄效应使铝液氢含量增加,实验铝液氢含量达到1.266 m L/100 g,铝液中的Al3Ti、Al2O3共同吸附铝液中的氢形成AlTiOH团簇,寄生于氧化铝夹杂表面的氢随氧化铝夹杂悬浮于铝液中,是铝液中氢含量明显升高的原因。
