The generation and optimization of attractive force between the coil and the workpiece is of significance for expanding the application of electromagnetic forming. In this work, a method using a low-frequency half-wave current is proposed to improve the attractive force, and to achieve a high-performance attractive forming. To verify the effectiveness of this method, an RLC circuit with a thyristor switch is introduced to generate the half-wave current, and the deformation behavior of an AA1060-H24 sheet is analyzed. According to both numerical and experimental investigations, it is demonstrated that the aluminum alloy sheet can be efficiently attracted toward the coil surface with a maximum deformation of more than 6 mm after a single discharge. On this basis, a series of simulations and experiments are carried out to clarify the effects of the discharge energy and current frequency on the attractive forming process. It is found that under the same forming depth, the required discharge energy and coil temperature rise for a smaller capacitance (1280 μF) can be decreased by almost 35% and 50%, respectively, compared to that for a larger capacitance (2880 μF). The obtained results are of certain value to promote the development of electromagnetic attractive forming.

The biological effects of magnetic fields (MFs) have been studied and applied in medicine over the past four decades. However, the influence of high-intensity pulse magnetic fields (HI-PMFs), theorized to exert even stronger biological effects, is rarely reported. Herein, a study was conducted to investigate the biological effects of 2.5 T HI-PMF on the model organism Escherichia coli and its corresponding physiological alterations. After being treated by HI-PMF, a notable increase was observed in its intracellular NADH/NAD⁺ ratio, coupled with an improved cell survival rate. Transcriptome analysis revealed significant upregulation of genes related to glucose metabolism. Subsequent experiments confirmed that if the initial intracellular glucose level was relatively high and markedly decreased after being treated with HI-PMF, the cell density would significantly rise, owing to the alleviated inhibition of cell division. On the contrary, a lower initial intracellular glucose level led to cell death under HI-PMF. Furthermore, reactive oxygen species (ROS) production was proved to be the main cause attributed to the above phenomena. Therefore, our study suggests that HI-PMF treatment promotes ROS production, enhances cellular glucose metabolism, and consequently influences cell division and survival rate according to the initial level of intracellular glucose.