在经典的双温模型中引入电子激发、载流子吸收等电离过程,建立了飞秒激光和晶体材料相互作用的理论模型。采用有限差分法数值模拟了在飞秒激光作用下,不同掺杂摩尔分数的Mg O∶Li Nb O3晶体内电子、晶格温度随飞秒激光脉宽、激光能量密...在经典的双温模型中引入电子激发、载流子吸收等电离过程,建立了飞秒激光和晶体材料相互作用的理论模型。采用有限差分法数值模拟了在飞秒激光作用下,不同掺杂摩尔分数的Mg O∶Li Nb O3晶体内电子、晶格温度随飞秒激光脉宽、激光能量密度的变化规律。并定量分析了不同掺杂摩尔分数的Mg O∶Li Nb O3晶体材料的损伤阈值随脉宽的变化规律,以及掺杂浓度对晶体损伤阈值的影响。结果表明,在Li Nb O3晶体中掺入适量的Mg O将使载流子迁移率发生变化,进而会影响晶体的损伤阈值。在适当掺杂范围内,掺Mg O的摩尔分数越高,载流子迁移率越大,晶体的损伤阈值越高。因此,实际应用中可通过在Li Nb O3晶体中掺入适量的Mg O来提高晶体的抗损伤能力。展开更多
Magnesium carbonate whisker as precursor was prepared from the low-grade magnesite tailings by the route of calcination, hydration, carbonation and thermal decomposition, and then MgO whisker was prepared by calcining...Magnesium carbonate whisker as precursor was prepared from the low-grade magnesite tailings by the route of calcination, hydration, carbonation and thermal decomposition, and then MgO whisker was prepared by calcining the precursor. In addition, the effect of MgO whisker addition on sintering and thermal shock resistance of refractory was also investigated. The results show that the thermal decomposition product is MgCO3·3H2O and its morphology is remarkably influenced by the types of additives, and magnesium carbonate whisker with the length of 10-60 μm and length-diameter ratio of 10-20 is successfully prepared when a type of soluble magnesium salt is added. MgO whisker with the length of 10-40 μm is derived from precursor with the heating rate of 1 ℃/min. The thermal shock resistance of refractory is significantly improved by the addition of MgO whisker due to its effect on binding and preventing crack expanding, and the proper amount of whisker addition is around 3%.展开更多
文摘在经典的双温模型中引入电子激发、载流子吸收等电离过程,建立了飞秒激光和晶体材料相互作用的理论模型。采用有限差分法数值模拟了在飞秒激光作用下,不同掺杂摩尔分数的Mg O∶Li Nb O3晶体内电子、晶格温度随飞秒激光脉宽、激光能量密度的变化规律。并定量分析了不同掺杂摩尔分数的Mg O∶Li Nb O3晶体材料的损伤阈值随脉宽的变化规律,以及掺杂浓度对晶体损伤阈值的影响。结果表明,在Li Nb O3晶体中掺入适量的Mg O将使载流子迁移率发生变化,进而会影响晶体的损伤阈值。在适当掺杂范围内,掺Mg O的摩尔分数越高,载流子迁移率越大,晶体的损伤阈值越高。因此,实际应用中可通过在Li Nb O3晶体中掺入适量的Mg O来提高晶体的抗损伤能力。
基金Projects(50874130,50974034)supported by the National Natural Science Foundation of ChinaProject(FMRU2008K01)supported by the Open Research Fund of Key Laboratory for Ferrous Metallurgy and Resources Utilization of Ministry of Education,Wuhan University of Science and Technology,China
文摘Magnesium carbonate whisker as precursor was prepared from the low-grade magnesite tailings by the route of calcination, hydration, carbonation and thermal decomposition, and then MgO whisker was prepared by calcining the precursor. In addition, the effect of MgO whisker addition on sintering and thermal shock resistance of refractory was also investigated. The results show that the thermal decomposition product is MgCO3·3H2O and its morphology is remarkably influenced by the types of additives, and magnesium carbonate whisker with the length of 10-60 μm and length-diameter ratio of 10-20 is successfully prepared when a type of soluble magnesium salt is added. MgO whisker with the length of 10-40 μm is derived from precursor with the heating rate of 1 ℃/min. The thermal shock resistance of refractory is significantly improved by the addition of MgO whisker due to its effect on binding and preventing crack expanding, and the proper amount of whisker addition is around 3%.
