Antibacterial activity of AISI420 stainless steel (SS) implanted by copper was investigated. Ions extracted from a metal vapor vacuum arc (MEVVA) are sourced with 100keV energy and a dose range from 0.2×1017 to 2...Antibacterial activity of AISI420 stainless steel (SS) implanted by copper was investigated. Ions extracted from a metal vapor vacuum arc (MEVVA) are sourced with 100keV energy and a dose range from 0.2×1017 to 2.0×1017ions·cm-2. The saturation dose of Cu implantation in AISI420 SS and Cu surface concentration were calculated at the energy of 100keV. The effect of dose on the antibacterial activity was analyzed. Results of antibacterial test show that the saturation dose is the optimum implantation dose for best antibacterial activity, which is above 99% against both Escherichia coli and Staphylococcus aureus. Novel phases such as Fe4Cu3 and Cu9.9Fe0.1 were found in the implanted layer by glancing angle X-ray diffraction (GXRD). The antibacterial activity of AISI420 SS attributes to Cu-contained phase.展开更多
Antibacterial activity has been studied by copper ion implantation into 0Cr18Ni9 stainless steel. Ions extracted from a metal vapor vacuum arc (MEVVA) are sourced with 60-100keV energy and a dose range (0.2-2.0)×...Antibacterial activity has been studied by copper ion implantation into 0Cr18Ni9 stainless steel. Ions extracted from a metal vapor vacuum arc (MEVVA) are sourced with 60-100keV energy and a dose range (0.2-2.0)×1017 ions cm-2. Saturation doses, surface concentration were calculated and the relationships between energy, dose and antibacterial activity were analyzed. Novel phases such as Fe4Cu3 and Cu0.81Ni0.19 were found after copper implantation by X-ray diffraction. The novel phases, effects on antibacterial activity have been investigated. The results show that saturation dose varies with the ions' energy. Antibacterial activity has close relation with copper,s concentration in implanted layer and Cu-rich phase.展开更多
The target backsheath field acceleration mechanism is one of the main mechanisms of laser-driven proton acceleration(LDPA)and strongly depends on the comprehensive performance of the ultrashort ultra-intense lasers us...The target backsheath field acceleration mechanism is one of the main mechanisms of laser-driven proton acceleration(LDPA)and strongly depends on the comprehensive performance of the ultrashort ultra-intense lasers used as the driving sources.The successful use of the SG-II Peta-watt(SG-II PW)laser facility for LDPA and its applications in radiographic diagnoses have been manifested by the good performance of the SG-II PW facility.Recently,the SG-II PW laser facility has undergone extensive maintenance and a comprehensive technical upgrade in terms of the seed source,laser contrast and terminal focus.LDPA experiments were performed using the maintained SG-II PW laser beam,and the highest cutoff energy of the proton beam was obviously increased.Accordingly,a double-film target structure was used,and the maximum cutoff energy of the proton beam was up to 70 MeV.These results demonstrate that the comprehensive performance of the SG-II PW laser facility was improved significantly.展开更多
基金This work was supported by the National Natural Science Foundation of China(No.50101009)
文摘Antibacterial activity of AISI420 stainless steel (SS) implanted by copper was investigated. Ions extracted from a metal vapor vacuum arc (MEVVA) are sourced with 100keV energy and a dose range from 0.2×1017 to 2.0×1017ions·cm-2. The saturation dose of Cu implantation in AISI420 SS and Cu surface concentration were calculated at the energy of 100keV. The effect of dose on the antibacterial activity was analyzed. Results of antibacterial test show that the saturation dose is the optimum implantation dose for best antibacterial activity, which is above 99% against both Escherichia coli and Staphylococcus aureus. Novel phases such as Fe4Cu3 and Cu9.9Fe0.1 were found in the implanted layer by glancing angle X-ray diffraction (GXRD). The antibacterial activity of AISI420 SS attributes to Cu-contained phase.
基金The National Natural Science Foundation of China(Grant No.50101009).
文摘Antibacterial activity has been studied by copper ion implantation into 0Cr18Ni9 stainless steel. Ions extracted from a metal vapor vacuum arc (MEVVA) are sourced with 60-100keV energy and a dose range (0.2-2.0)×1017 ions cm-2. Saturation doses, surface concentration were calculated and the relationships between energy, dose and antibacterial activity were analyzed. Novel phases such as Fe4Cu3 and Cu0.81Ni0.19 were found after copper implantation by X-ray diffraction. The novel phases, effects on antibacterial activity have been investigated. The results show that saturation dose varies with the ions' energy. Antibacterial activity has close relation with copper,s concentration in implanted layer and Cu-rich phase.
基金National Natural Science Foundation of China(Grant No.12075227)the National Natural Science Foundation of China-NSAF(Grant No.U2130121)+1 种基金the National Key Research and Development Program of China(Grant No.2016YFA0401102)the Science Challenge Project(Grant No.TZ2018005).
文摘The target backsheath field acceleration mechanism is one of the main mechanisms of laser-driven proton acceleration(LDPA)and strongly depends on the comprehensive performance of the ultrashort ultra-intense lasers used as the driving sources.The successful use of the SG-II Peta-watt(SG-II PW)laser facility for LDPA and its applications in radiographic diagnoses have been manifested by the good performance of the SG-II PW facility.Recently,the SG-II PW laser facility has undergone extensive maintenance and a comprehensive technical upgrade in terms of the seed source,laser contrast and terminal focus.LDPA experiments were performed using the maintained SG-II PW laser beam,and the highest cutoff energy of the proton beam was obviously increased.Accordingly,a double-film target structure was used,and the maximum cutoff energy of the proton beam was up to 70 MeV.These results demonstrate that the comprehensive performance of the SG-II PW laser facility was improved significantly.
