微波作用下硅藻土酸浸除铁过程研究

研究在微波作用下硅藻土酸浸除铁过程的影响因素和工艺条件。结果表明。硫酸浓度、微波功率和浸出时间对硅藻土除铁均有影响，浸出时间是影响浸出的最主要因素，微波功率和硫酸浓度次之。随浸出时间延长。微波功率增加，硫酸浓度加大，硅藻土中的Fe2O3含量减少。Fe2O3浸出率增加。在试验条件下。较佳的工艺条件为硫酸浓度40％，浸出时间45min，微波功率260W。在此条件下获得的硅藻土产品指标为SiO283．50％，Al2O37．18％，Fe2O30．87％，达到了硅藻土助滤剂质量标准SiO2〉80％，Al2O3〈10％。Fe2O3〈2％。     

氧化铁硫杆菌的微波诱变及对低品位黄铜矿的生物浸出

研究微波辐照诱变氧化铁硫杆菌T.f菌以及浸出低品位黄铜矿的效果。结果表明,微波辐照能够引起浸矿细菌产生变异,提高菌种的活性。诱变菌比原始菌的活性提高了39.96%。T.f菌经微波处理,浸矿性能有明显提高。与T.f菌相比,诱变后的T.f菌对原生铜矿的浸出率提高了31.44%,对易浸的次生硫化铜矿浸出率从53.66%提高到74.97%,总铜浸出率从32.43%提高到56.58%,浸出终点比原始菌提前了5～10d。诱变后的T.f菌对以黄铜矿为主的多金属铜矿具有较好的浸出效果。     

用微波烘干法代替酒精燃烧法测定土样的含水量

野外工程实践证明，用微波烘干法测定土样的含水量，比用酒精燃烧法具有快速、准确、简便、节能和安全等优点，可完全替代之．若研制专用干燥微波炉，有望替代烘箱．     

小球表面粗糙度和温度对石榴石多晶铁氧体铁磁共振线宽的影响

用普通陶瓷工艺制备小线宽石榴石多晶铁氧体材料,用压缩空气吹磨法和研磨膏研磨法对石榴石小球表面进行了抛光,按GB9633(等同采用IEC60556)标准)在9.37GHz下测量了小线宽石榴石铁氧体材料的铁磁共振线宽ΔH。讨论了ΔH与抛光粉粒度的关系,比较了压缩空气法与研磨法的抛光效果。在7?30℃环境温度区间,测量了小线宽材料的ΔH随温度的变化。     

外加磁场对石榴石铁氧体介电损耗测量值的影响和性能与缺铁量的关系

用普通陶瓷工艺制备YIGs、YGdIGs和BiCaVIGs等系列石榴石多晶铁氧体,按GB9633(等同IEC60556)标准在10.7GHz下测量了复合石榴石YIGs、YGdIGs和BiCaVIGs的介电常数ε′和介电损耗角正切tanδε,同时也测量了9.37GHz下的铁磁共振线宽DH。比较了加与不加稳恒磁场时ε′和tanδε的测量结果,讨论了加磁场后介电损耗的下降。此外还研究了tanδε和DH与缺铁量的关系,分析了DH最小值对应的缺铁量和tanδε最小值对应的缺铁量不重合的原因。     

多功能微波功率检测模块设计

对于大多数射频微波系统,微波功率都是一个必不可少的评价指标.对于中小型的微波功率源系统,为满足系统的可测试性,往往需要增加对输出功率的量化检测,但使用仪表功率计则价格昂贵.详细介绍了一种简单、实用、经济性好的微波功率检测模块设计方法.该方法使用线性检波、采样保持、数据采集及软件校准等方法,实现了较高精度的峰值功率、调制脉冲功率信号脉冲重频及脉宽的检测,并通过试验将测试数据与功率计及示波器实际测量对比,验证了使用该方法研制模块测试精度.     

基于关联信息的红外微波复合探测技术研究

针对红外微波复合探测的目标识别问题,提出了基于关联信息的多传感器复合探测目标识别方法,通过红外与微波传感器对真实探测目标和虚假干扰目标的回波差异分析,采用关联信息融合的方法提取相应的特征参数进行对比与分析。在此基础上建立了红外微波传感器探测目标识别的数学模型,并分析研究了基于关联信息的红外与微波复合探测目标识别问题,最后通过实验的方式加以验证并得出结论,该种方法在目标探测及识别方面具有较为显著的效果。     

Microwave-specific heating of crystalline species in nuclear waste glass

The microwave heating of a crystal-free and a partially trevorite-crystallized nuclear waste glass simulant was evaluated. Our results show that a 500-mg monolith of partially crystallized waste glass can be heated from room temperature to above 1600°C within 2 minutes using a single-mode, highly focused, 2.45-GHz microwave, operating at 300 W. Using X-ray diffraction measurements, we show that trevorite is no longer detectable after irradiation and thermal quenching. When a crystal-free analog of the same waste glass simulant composition was exposed to the same microwave radiation, it could not be heated above 450°C regardless of the heating time. The reduction in crystalline content achieved by selectively heating spinels in the presence of glass suggests that microwave-specific heating should be further explored as a technique for remediating crystal accumulation in a glass melt.     

Characteristics of precipitated calcium carbonate by hydrothermal and carbonation processes with mega-crystalline calcite using rotary microwave kiln

In the conventional kiln, mega-crystalline calcite (m-CC) breaks apart easily during calcinations, and cannot be easily converted to CaO due to that it requiring a lot of heat. In this study, m-CC was calcined to CaO of around 1 mm using the rotary microwave kiln. Furthermore, CaCO₃ was produced by the carbonation process and hydrothermal process, and the form of CaCO₃ was characterized.Calcination of m-CC using the rotary microwave kiln resulted in CaO (97 wt%) of relatively fine size.CaCO₃ of colloidal-shaped and 6 μm in size could be prepared by applying the carbonation process to Ca(OH)₂ using a bubble reactor at 25 °C. As the carbonation temperature increased from 25 to 80 °C, the shape of prepared CaCO₃ changed from a colloidal-type to spindle-type of 1 μm due to self-assembly. Also, hexagonal-shaped aragonite could be prepared by the hydrothermal process with the supersaturated Ca(HCO₃)₂ solutions.     

Rapid and Efficient Functionalized Ionic Liquid-Catalyzed Aldol Condensation Reactions Associated with Microwave Irradiation

Five quaternary ammonium ionic liquid (IL) and two tetrabutylphosphonium ILs were prepared and characterized. An environmentally benign and convenient functionalized ionic liquid catalytic system was thus explored in the aldol condensation reactions of aromatic aldehydes with acetone. The aldol reactions proceeded more efficiently through microwave-assisted heating than through conventional thermal heating. The yield of products obtained under microwave heating for 30 min was approximately 90%, and the ILs can be recovered and reused at least five times without apparent loss of activity. In addition, this catalytic system can be successfully extended to the Henry reactions.