| Often,harsh conditions can exist in a variety of complex environments,and there can be toxic and harmful conditions.Using wireless self-powered sensors has huge advantages.However,in harsh environments,self-powered sensors still have the risk of device damage due to short circuits.Based on electrostatic spinning,a single-electrode self-powered piezoelectric sensor is designed.This sensor can be used to monitor human movements,such as walking and running,and to monitor the working status of certain mechanical equipment,such as peristaltic pumps,and the opening and closing of doors and windows.A threshold delay algorithm has been written to warn the user to check related safety and related devices when the door and window are opened and the peristaltic pump stops working.The sensor can be connected to a mobile phone using a Bluetooth device to receive real-time signals on the mobile phone.Further research shows that,unlike a twoelectrode sensor,a single-electrode configuration can avoid short-circuit behavior caused by device damage,so that the self-powered sensor can work normally even if punctured,so the wireless single-electrode self-powered sensor system has better reliability,And more suitable for harsh environments.Specific separation methods for specific particles have been an urgent need in some special environments.Alginate,a non-toxic,biocompatible,and easily degradable material,was prepared using electrostatic spinning and displacement reactions to prepare a magnetic copper alginate fiber membrane for filtering magnetic particles in liquids.It can realize solid-liquid separation of magnetic particle system.The filter membrane showed better magnetic filtration performance than commercial filter paper.Potential applications in a variety of specific environments.In addition,Sm1-xLaxFeO3 was prepared by doping La ions into SmFeO3 using a solid phase reaction.La ions are successfully doped without phase change,and the doping ratio can reach 20%.The effects of La ion doping on the structure and magnetic properties of the samples were studied.By diluting magnetic Sm ions with such non-magnetic La ions,the magnetic anisotropy performance first increases and then decreases.The hysteresis loop has undergone a significant change,exhibiting exchange bias.The exchange bias field also increases first and then decreases.The crystal lattice did not change significantly,nor did the iron spins change.It can be observed that the temperature-induced spin switch occurs after the zero-field cooling process. |
