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Using the mutual conversion between electric energy and magnetic energy, we designed and built an experimental device based on the o-core transformer structure for extraction of garlic polysaccharides. That is, an acidic solvent acted as the secondary coil conductor under the action of alternating magnetic flux and then induced an electric field in the biochemical medium (the sample and extractant) at 20-60 kHz. The polysaccharide yield improved, in comparison to the conventional heating method, when the excitation voltage applied on the primary coil was increased. Low pH helps to improve the polysaccharide yield due to the enhancement of the ionic conduction resulting from the induced electric field. However, the polysaccharide yield decreases with the increase of partial frequency due to the resulting decrease in the input power of the system. The orthogonal experiments showed that the excitation voltage, frequency, pH, and temperature all significantly affected the polysaccharide yield. The garlic polysaccharide extracted by using the induced electric field method had a DPPH radical scavenging ability and a ferric-reducing power. This novel system is a potential alternative for the extraction of garlic polysaccharides without the use of powered electrodes inserted into solutions, unlike other electric-field-assisted techniques. [ABSTRACT FROM AUTHOR]

[Display omitted] • Developing the coordinative unsaturation (Fe-N 2) with nitrogen vacancies. • Nitrogen vacancies and Fe-N 2 active site for boosting electrochemical artificial N 2 fixation. • In situ environmental TEM directly visualize N 2 adsorption on FePcTa-PPy. • Fe-N 2 -opp possesses lower overpotential and excellent dynamics stability for ENRR. The construction of definitive correlation between structure and catalytic properties for electrochemical artificial N 2 fixation is still challenging yet significative. Herein, we have explored the coordinative unsaturation (Fe-N 2) in isolated Fe atoms with nitrogen vacancies (V N, which are located at the opposite coordination sites of the Fe atom) on interconnected carbon for electrocatalytic ammonia synthesis. Benefiting from dual active centers (Fe-N 2 and V N) and the spin density on both of them, the novel catalyst exhibits a synergistic improvement of catalytic activity, selectivity, and stability. This work guides the design of the catalyst theoretically and synergistically and combines the advantages of Fe-N 2 with V N structure creation, defect and spin-state engineering introduction toward the concurrent fulfillment of effective N 2 adsorption and activation. We believe our strategy will incite more investigation into designing high-performance catalysts with well-defined coordinative unsaturation single-atom active sites for ambient ammonia synthesis and other energy conversion system. [ABSTRACT FROM AUTHOR]