为了准确地检测出粉煤灰中残留的氨含量,分析了纳氏分光光度法、中和滴定法和氨气敏电极法检测粉煤灰中残留氨含量的主要影响因素,探讨了这3种检测方法的主要影响因素的最佳值选取,研究了3种方法结果的相关性。结果表明:影响纳氏分光光...为了准确地检测出粉煤灰中残留的氨含量,分析了纳氏分光光度法、中和滴定法和氨气敏电极法检测粉煤灰中残留氨含量的主要影响因素,探讨了这3种检测方法的主要影响因素的最佳值选取,研究了3种方法结果的相关性。结果表明:影响纳氏分光光度法的主要因素为浸提剂、浸提固液比和浸提时间,最佳值选取分别为0.05 mol/L H 2 SO 4、1∶10和30 min;影响中和滴定法的主要因素为吸收溶液、氢氧化钠加入量和蒸馏时间,最佳值选取分别为0.05 mol/L H 2 SO 4、0.2 g和30 min;影响氨气敏电极法的主要因素为提取液和搅拌时间,最佳值选取分别为去离子水和[10,25]min。同时,这3种方法检测结果的相关性较好。研究成果探究了适用于有效定量检测粉煤灰中残留氨的方法,为控制和限定粉煤灰中残留氨提供检测基础。展开更多
Creep age forming techniques have been widely used in aerospace industries. In this study, we investigated the effect of aging temperature(143 °C-163 °C) on the creep behavior of Al-Li-S4 aluminum alloy and ...Creep age forming techniques have been widely used in aerospace industries. In this study, we investigated the effect of aging temperature(143 °C-163 °C) on the creep behavior of Al-Li-S4 aluminum alloy and their mechanical properties at room temperature. The mechanical properties were tested by tensile testing, and the microstructural evolution at different aging temperatures was examined by transmission electron microscopy. Results show that the creep strains and the room-temperature mechanical properties after creep aging increase with the aging temperature. As the aging temperature increases, the creep strain increases from 0.018% at 143 °C to 0.058% at 153 °C, and then to 0.094% at 163 °C. Within 25 h aging, the number of creep steps increases and the duration time of the same steps is shortened with the growth of aging temperatures. Therefore, the increase in aging temperatures accelerates the progress of the entire creep. Two main strengthening precipitates θ′(Al2 Cu) and T1(Al2 Cu Li) phases were characterized. This work indicates that the creep strain and mechanical properties of Al-Li-S4 alloys can be improved by controlling aging temperatures.展开更多
文摘为了准确地检测出粉煤灰中残留的氨含量,分析了纳氏分光光度法、中和滴定法和氨气敏电极法检测粉煤灰中残留氨含量的主要影响因素,探讨了这3种检测方法的主要影响因素的最佳值选取,研究了3种方法结果的相关性。结果表明:影响纳氏分光光度法的主要因素为浸提剂、浸提固液比和浸提时间,最佳值选取分别为0.05 mol/L H 2 SO 4、1∶10和30 min;影响中和滴定法的主要因素为吸收溶液、氢氧化钠加入量和蒸馏时间,最佳值选取分别为0.05 mol/L H 2 SO 4、0.2 g和30 min;影响氨气敏电极法的主要因素为提取液和搅拌时间,最佳值选取分别为去离子水和[10,25]min。同时,这3种方法检测结果的相关性较好。研究成果探究了适用于有效定量检测粉煤灰中残留氨的方法,为控制和限定粉煤灰中残留氨提供检测基础。
基金Project(2017YFB0306300)supported by National key R&D Program of ChinaProject(zzyikt2015-05)supported by the Project of State Key Laboratory of High Performance Complex Manufacture,China。
文摘Creep age forming techniques have been widely used in aerospace industries. In this study, we investigated the effect of aging temperature(143 °C-163 °C) on the creep behavior of Al-Li-S4 aluminum alloy and their mechanical properties at room temperature. The mechanical properties were tested by tensile testing, and the microstructural evolution at different aging temperatures was examined by transmission electron microscopy. Results show that the creep strains and the room-temperature mechanical properties after creep aging increase with the aging temperature. As the aging temperature increases, the creep strain increases from 0.018% at 143 °C to 0.058% at 153 °C, and then to 0.094% at 163 °C. Within 25 h aging, the number of creep steps increases and the duration time of the same steps is shortened with the growth of aging temperatures. Therefore, the increase in aging temperatures accelerates the progress of the entire creep. Two main strengthening precipitates θ′(Al2 Cu) and T1(Al2 Cu Li) phases were characterized. This work indicates that the creep strain and mechanical properties of Al-Li-S4 alloys can be improved by controlling aging temperatures.
