改性成都粘土预处理垃圾渗滤液的吸附热力学和动力学研究

本文采用十六烷基三甲基溴化铵(HDTMA)对成都粘土进行改性,将改性粘土用于垃圾渗滤液处理,对处理过程的吸附热力学和动力学进行研究。研究表明,分别在303.15K、313.15K和333.15K下,粘土吸附渗滤液中氨氮和有机物的平衡时间为50min左右,改性后的粘土吸附效果比原土提高了大约2～3倍;改性粘土对氨氮的吸附既符合Langmuir等温吸附,也符合Freundlich等温模型,对有机物的吸附更符合Freundlich等温模型;此反应过程均属自发的放热过程,其吸附动力学数据符合准二级动力学方程和粒子内扩散方程。     

Mapping an on-chip terahertz antenna by a scanning near-field probe and a fixed field-effect transistor

In the terahertz(THz) regime,the active region for a solid-state detector usually needs to be implemented accurately in the near-field region of an on-chip antenna.Mapping of the near-field strength could allow for rapid verification and optimization of new antenna/detector designs.Here,we report a proof-of-concept experiment in which the field mapping is realized by a scanning metallic probe and a fixed AlGaN/GaN field-effect transistor.Experiment results agree well with the electromagnetic-wave simulations.The results also suggest a field-effect THz detector combined with a probe tip could serve as a high sensitivity THz near-field sensor.