Atmospheric pressure plasma jet utilizing Ar and Ar/H_2O mixtures and its applications to bacteria inactivation

An atmospheric pressure plasma jet generated with Ar with H2O vapor is characterized and applied to inactivation of Bacillus subtilis spores. The emission spectra obtained from Ar/H2O plasma shows a higher intensity of OH radicals compared to pure argon at a specified H2O concentration. The gas temperature is estimated by comparing the simulated spectra of the OH band with experimental spectra. The excitation electron temperature is determined from the Boltzmann’s plots and Stark broadening of the hydrogen Balmer Hβline is applied to measure the electron density. The gas temperature, excitation electron temperature, and electron density of the plasma jet decrease with the increase of water vapor concentration at a fixed input voltage. The bacteria inactivation rate increases with the increase of OH generation reaching a maximum reduction at 2.6%(v/v) water vapor. Our results also show that the OH radicals generated by the Ar/H2O plasma jet only makes a limited contribution to spore inactivation and the shape change of the spores before and after plasma irradiation is discussed.     

锌粉还原法合成对苯二胺的研究

在酸性介质中，用锌粉还原对硝基苯胺制备对苯二胺，通过影响反应因素的研究，如反应物配比、温度、反应时间等，寻找出了较佳反应条件：对硝基苯胺与锌粉的摩尔比为1:4，反应温度为80-85℃，反应时间为6h，对苯二胺的产率可达90%。克服了铁粉还原法的弊端，为对苯二胺的工业化生产提供了可靠的依据。     

低功率电弧放电辅助甲烷燃烧的实验研究

利用低功率电弧放电辅助甲烷燃烧,研究了在不同甲烷/空气比例的情况下,等离子体对甲烷燃烧的影响。采用发射光谱仪进行光谱诊断,比较有/无等离子体辅助甲烷燃烧火焰发射光谱的异同,讨论了等离子体辅助燃烧可能发生的过程和机理。比较有/无等离子体辅助甲烷燃烧火焰温度的变化。利用气相色谱和烟气分析仪对甲烷燃烧产物中的CH₄、CO 和O₂ 进行分析。实验结果表明,加等离子体后,火焰的温度升高,尾气中的可燃性成分减少,氧气含量降低,在很大程度上提高了甲烷的燃烧效率;甲烷/空气的比例越低,燃烧效率的提高越明显;甲烷的富燃燃烧极限从16%调高到21%。