Non-thermal plasma jet at atmospheric pressure has recently attracted lots of attention because of its applications in plasma bullet or plasma plume.Thus,we studied on generating plasma jet by coplanar dielectric barr...Non-thermal plasma jet at atmospheric pressure has recently attracted lots of attention because of its applications in plasma bullet or plasma plume.Thus,we studied on generating plasma jet by coplanar dielectric barrier discharge in a device driven by sinusoidal voltage.The processes of plasma discharges in both positive and negative half cycles were recorded using a high-speed ICCD(intensified charge-coupled device)camera;based on the results we estimated the velocity of plasma propagation,and investigated the influence of gas flow on the plasma development.It is shown that the plasma bullets,which have velocity in the order of 103～104m/s,exist only outside the cathode.APPJ(atmospheric pressure plasma jet)is created by the electron beam from the cathode,and then sustained by a strong radial electric field near and outside the cathode.The gas flow influences the APPJ length in air but not the APPJ discharge,while the discharge is affected significantly by the applied voltage.展开更多
Bacterial and chemical contaminations of drinking water imperil the health of people.A reactive species injection method is presented for sterilizing drinking water.To produce reactive species,a gas phase surface disc...Bacterial and chemical contaminations of drinking water imperil the health of people.A reactive species injection method is presented for sterilizing drinking water.To produce reactive species,a gas phase surface discharge reactor(SDR)is designed:a spiral stainless steel wire attached on the inside wall of a quartz glass tube is used as the high voltage electrode,and the drinking water is the ground electrode.The performance and mechanisms of the method in inactivating of Escherichia coli(E.coli)are analyzed.Experimental results show that 500 mL E.coli-contaminated drinking water(108CFU/mL)is completely sterilized within 4 min.Based on the scanning electron microscope(SEM)analysis,there were plasma-induced cell structure damages of the E.coli in the sterilized water,and the damage resulted in the leakage of protein,which was proved by chemical analyses.Meanwhile,the heating effect concomitantly generated by discharge plasma does not influence E.coli inactivation,and the contribution of direct ultraviolet(UV)irradiation could be neglected too.The ozone generated by SDR and the hydroxyl radicals(·OH)subsequently generated in drinking water play the decisive roles in E.coli inactivation because these reactive species cause the cell rupture.展开更多
基金Project supported by National Natural Science Foundation of China （10875010 11175017）.
文摘Non-thermal plasma jet at atmospheric pressure has recently attracted lots of attention because of its applications in plasma bullet or plasma plume.Thus,we studied on generating plasma jet by coplanar dielectric barrier discharge in a device driven by sinusoidal voltage.The processes of plasma discharges in both positive and negative half cycles were recorded using a high-speed ICCD(intensified charge-coupled device)camera;based on the results we estimated the velocity of plasma propagation,and investigated the influence of gas flow on the plasma development.It is shown that the plasma bullets,which have velocity in the order of 103～104m/s,exist only outside the cathode.APPJ(atmospheric pressure plasma jet)is created by the electron beam from the cathode,and then sustained by a strong radial electric field near and outside the cathode.The gas flow influences the APPJ length in air but not the APPJ discharge,while the discharge is affected significantly by the applied voltage.
基金Project supported by Ministry of Science and Technology of China （2008AA06Z308）, National Natural Science Foundation of China （40901150）, Joint Fund of the National Natural Science Foundation of China （U0970166）, Doctoral Program Foundation of Institutions of Higher Education of China （20070141004）, Program for Liaoning Excel- lent Talents in University of China （2009R09）, Fundamental Research Fund for the Central Universities （DUT12RC（3）12）.
文摘Bacterial and chemical contaminations of drinking water imperil the health of people.A reactive species injection method is presented for sterilizing drinking water.To produce reactive species,a gas phase surface discharge reactor(SDR)is designed:a spiral stainless steel wire attached on the inside wall of a quartz glass tube is used as the high voltage electrode,and the drinking water is the ground electrode.The performance and mechanisms of the method in inactivating of Escherichia coli(E.coli)are analyzed.Experimental results show that 500 mL E.coli-contaminated drinking water(108CFU/mL)is completely sterilized within 4 min.Based on the scanning electron microscope(SEM)analysis,there were plasma-induced cell structure damages of the E.coli in the sterilized water,and the damage resulted in the leakage of protein,which was proved by chemical analyses.Meanwhile,the heating effect concomitantly generated by discharge plasma does not influence E.coli inactivation,and the contribution of direct ultraviolet(UV)irradiation could be neglected too.The ozone generated by SDR and the hydroxyl radicals(·OH)subsequently generated in drinking water play the decisive roles in E.coli inactivation because these reactive species cause the cell rupture.
