有机化学课程人物思政元素教学融入方法探索——以邮票上的“吉森学派”为例

化学人物的教学融入是有机化学课程思政教学过程中的重要组成部分和必不可少的环节。化学主题邮票作为一类特色的教学资源和载体,蕴含着丰富的思政育人内容。本文针对农学类有机化学课程开展了以“吉森学派”化学人物主题邮票为主线之一的大学化学教学实践。对化学主题邮票应用于教学的简要历史、可行性和意义加以分析,并对化学人物主题邮票这一特色载体融入教学的方法、效果和反思进行总结,旨在为此类教学开展提供参考。

In situ quantification of NO synthesis in a warm air glow discharge by WMS-based Mid-IR QCL absorption spectroscopy

Nitric oxide(NO)is one of the most crucial products in the plasma-based nitrogen fixation process.In this work,in situ measurements were performed for quantifying the NO synthesis spatially in a warm air glow discharge,through the method of Mid-infrared quantum cascade laser absorption spectroscopy(QCL-AS).Two ro-vibrational transitions at 1900.076 cm^(-1) and 1900.517 cm^(-1) of the ground-state NO(X)were probed sensitively by the help of the wavelength modulation spectroscopy(WMS)approach to increase the signal/noise(S/N)level.The results show a decline trend of NO synthesis rate along the discharge channel from the cathode to the anode.However,from the point of energy efficiency,the cathode region is of significantly low energy efficiency of NO production.Severe disproportionality was found for the high energy consumption but low NO production in the region of cathode area,compared to that in the positive column zone.Further analysis demonstrates the high energy cost of NO production in the cathode region,is ascribed to the extremely high reduced electric field E/N therein not selectively preferable for the processes of vibrational excitation or dissociation of N_(2) and O_(2) molecules.This drags down the overall energy efficiency of NO synthesis by this typical warm air glow discharge,particularly for the ones with short electrode gaps.Limitations of further improving the energy cost of NO synthesis by variations of the discharge operation conditions,such as discharge current or airflow rate,imply other effective manners able to tune the energy delivery selectively to the NO formation process,are sorely needed.

Preliminary study of an open-air water-contacting discharge for direct nitrogen fixation

Efficient nitrogen fixation through a reactive plasma process attracts intense interest due to the environmental issues induced by the conventional Haber–Bosch method. In this work, we present a direct and simple fixation routine without any catalysts for nitrogen in open air using an atmospheric-pressure pin-to-solution plasma electrolytic system. Nitrate, nitrite, and ammonia as the nitrogen-derived chemicals in solution were analyzed as indicators under various discharge conditions to estimate the energy efficiency of this process. The results show that the nitrogen fixation process was much more efficient by the pin-positive discharge compared to the negative one. N chemicals preferred to be formed when the solution was of negative polarity. It was also found that, with the help of solution circulation, the energy efficiency was enhanced compared to that of static liquid. However, an inverse trend was observed with the increase of the discharge current. Further study by optical emission spectroscopy indicates the important roles of active N2* and water vapour and their derived species near the plasma–water interface in the fixation process.