The objective of the present study is to develop heterogeneous microstructure in cold-rolled medium Mn steels(MMSs)annealing strategy.The cold-rolled Fe-4.7Mn-0.15C(wt%)steel is annealed twice at different temperature...The objective of the present study is to develop heterogeneous microstructure in cold-rolled medium Mn steels(MMSs)annealing strategy.The cold-rolled Fe-4.7Mn-0.15C(wt%)steel is annealed twice at different temperatures to produce an ultra-fine heterogeneous microstructure with lath-shaped and granular-shaped retained austenite.Excellent mechanical behavior of significant strength enhancement with negligible ductility loss can be achieved.The high strength-ductility properties are attributed to the active transformation induced plasticity effect over a broad strain range owing to dispersive mechanical stabilities of the heterogeneous austenite.Furthermore,the typical yield point elongation phenomenon which is commonly observed in cold-rolled MMSs can be effectively reduced by this microstructural strategy.展开更多
To avoid pollution of generator exhaust port after the ship docked, the use of shore power supply is developing direction of port. And the shore power grounding method and related standards needed to be carried out. A...To avoid pollution of generator exhaust port after the ship docked, the use of shore power supply is developing direction of port. And the shore power grounding method and related standards needed to be carried out. According to developing status of foreign medium voltage ship and characteristics of navy shipboard power supply, this paper presents a shore power supply network structure and its grounding method. The simulation results show the power supply network structure can effectively suppress the single-phase intermittent ground fault on the system to produce the harm.展开更多
In this study,we investigated the effects of the quartz tube diameter,air flow rate,and applied voltage on the characteristics of an air plasma jet to obtain the optimized discharge characteristics.The physicochemical...In this study,we investigated the effects of the quartz tube diameter,air flow rate,and applied voltage on the characteristics of an air plasma jet to obtain the optimized discharge characteristics.The physicochemical properties and concentration of reactive oxygen and nitrogen species(RONS)in plasma-activated medium(PAM)were characterized to explore their chemical activity.Furthermore,we investigated the inactivation effect of air plasma jet on tumour cells and their corresponding inactivation mechanism.The results show that the tube diameter plays an important role in sustaining the voltage of the air plasma jet,and the gas flow rate affects the jet length and discharge intensity.Additionally,the air plasma jet discharge displays two modes,namely,ozone and nitrogen oxide modes at high and low gas flow rates,respectively.Increasing the voltage increases the concentration of reactive species and the length of discharge.By evaluating the viability of A549 cells under different parameters,the optimal treatment conditions were determined to be a quartz tube diameter of 4 mm,gas flow rate of 0.5 SLM,and voltage of 18 k V.Furthermore,an air plasma jet under the optimized conditions effectively enhanced the chemical activity in PAM and produced more aqueous RONS.The air plasma jet induced significant cytotoxicity in A549 cancer cells after plasma treatment.H_(2)O_(2) and NO_(2) are regarded as key factors in promoting cell inactivation.The present study demonstrates the potential use of tumour cell therapy by atmospheric air PAM,which aids a better understanding of plasma liquid chemistry.展开更多
基金financially supported by the National Natural Science Foundation of China(Nos.52071322 and 51771192).
文摘The objective of the present study is to develop heterogeneous microstructure in cold-rolled medium Mn steels(MMSs)annealing strategy.The cold-rolled Fe-4.7Mn-0.15C(wt%)steel is annealed twice at different temperatures to produce an ultra-fine heterogeneous microstructure with lath-shaped and granular-shaped retained austenite.Excellent mechanical behavior of significant strength enhancement with negligible ductility loss can be achieved.The high strength-ductility properties are attributed to the active transformation induced plasticity effect over a broad strain range owing to dispersive mechanical stabilities of the heterogeneous austenite.Furthermore,the typical yield point elongation phenomenon which is commonly observed in cold-rolled MMSs can be effectively reduced by this microstructural strategy.
文摘To avoid pollution of generator exhaust port after the ship docked, the use of shore power supply is developing direction of port. And the shore power grounding method and related standards needed to be carried out. According to developing status of foreign medium voltage ship and characteristics of navy shipboard power supply, this paper presents a shore power supply network structure and its grounding method. The simulation results show the power supply network structure can effectively suppress the single-phase intermittent ground fault on the system to produce the harm.
基金supported by National Natural Science Foundation of China(Nos.12075188,52077166 and 51837008)State Key Laboratory of Electrical Insulation and Power Equipment(No.EIPE20302).
文摘In this study,we investigated the effects of the quartz tube diameter,air flow rate,and applied voltage on the characteristics of an air plasma jet to obtain the optimized discharge characteristics.The physicochemical properties and concentration of reactive oxygen and nitrogen species(RONS)in plasma-activated medium(PAM)were characterized to explore their chemical activity.Furthermore,we investigated the inactivation effect of air plasma jet on tumour cells and their corresponding inactivation mechanism.The results show that the tube diameter plays an important role in sustaining the voltage of the air plasma jet,and the gas flow rate affects the jet length and discharge intensity.Additionally,the air plasma jet discharge displays two modes,namely,ozone and nitrogen oxide modes at high and low gas flow rates,respectively.Increasing the voltage increases the concentration of reactive species and the length of discharge.By evaluating the viability of A549 cells under different parameters,the optimal treatment conditions were determined to be a quartz tube diameter of 4 mm,gas flow rate of 0.5 SLM,and voltage of 18 k V.Furthermore,an air plasma jet under the optimized conditions effectively enhanced the chemical activity in PAM and produced more aqueous RONS.The air plasma jet induced significant cytotoxicity in A549 cancer cells after plasma treatment.H_(2)O_(2) and NO_(2) are regarded as key factors in promoting cell inactivation.The present study demonstrates the potential use of tumour cell therapy by atmospheric air PAM,which aids a better understanding of plasma liquid chemistry.
