Al-Zn-Mg alloys with different Zn/Mg mass ratios were evaluated as sacrificial anodes for cathodic protection of carbon steel in 3.5 wt.%Na Cl solution.The anodes were fabricated from pure Al,Zn and Mg metals using ca...Al-Zn-Mg alloys with different Zn/Mg mass ratios were evaluated as sacrificial anodes for cathodic protection of carbon steel in 3.5 wt.%Na Cl solution.The anodes were fabricated from pure Al,Zn and Mg metals using casting technique.Optical microscopy,SEM-EDS,XRD and electrochemical techniques were used.The results indicated that with decreasing Zn/Mg mass ratio,the grain size ofα(Al)and the particle size of the precipitates decreased while the volume fraction of the precipitates increased.The anode with Zn/Mg mass ratio>4.0 exhibited the lowest corrosion rate,while the anode with Zn/Mg mass ratio<0.62 gave the highest corrosion rate and provided the highest cathodic protection efficiency for carbon steel(AISI 1018).Furthermore,the results showed that the anode with Zn/Mg mass ratio<0.62 exhibited a porous corrosion product compared to the other anodes.展开更多
A highly pixelated and luminescent silica-coated quantum dot color filter(QDCF)was achieved by surface conjugation with epoxy functional group.Epoxy-functionalized silica-coated quantum dots(QDs)can be thoroughly mixe...A highly pixelated and luminescent silica-coated quantum dot color filter(QDCF)was achieved by surface conjugation with epoxy functional group.Epoxy-functionalized silica-coated quantum dots(QDs)can be thoroughly mixed with SU-8 photoresist up to 25 wt.%without aggregation.The quantum yield(QY)of the silica-coated QDCF can be significantly improved from 19.3%to 36.5%after epoxy treatment.The pristine QDCF experienced a 40%QY decrease,while the epoxied silica-coated QDCF maintained its luminescence even after irradiation(300 mW cm 2@450 nm)for over 25 days.The well-controlled epoxy cap plays a critical role in attaining the ideal optical properties of the QDCF.展开更多
Under hypersonic flight conditions,the sharp cowl-lip leading edges have to be blunted because of the severe aerodynamic heating.This paper proposes four cowl-lip blunting methods and studies the corresponding flow ch...Under hypersonic flight conditions,the sharp cowl-lip leading edges have to be blunted because of the severe aerodynamic heating.This paper proposes four cowl-lip blunting methods and studies the corresponding flow characteristics and performances of the generic hypersonic inlets by numerical simulation under the design conditions of a flight Mach number of 6 and an altitude of 26 km.The results show that the local shock interference patterns in the vicinity of the blunted cowl-lips have a substantial influence on the flow characteristics of the hypersonic inlets even though the blunting radius is very small,which contribute to a pronounced degradation of the inlet performance.The Equal Length blunting Manner(ELM)is the most optimal in that a nearly even reflection of the ramp shock produces an approximately straight and weak cowl reflection shock.The minimal total pressure loss,the lowest cowl drag,maximum mass-capture and the minimal aeroheating are achieved for the hypersonic inlet.For the other blunting manners,the ramp shock cannot reflect evenly and produces more curved cowl reflection shock.The Type V shock interference pattern occurs for the Cross Section Cutting blunting Manner(CSCM)and the strongest cowl reflection shock gives rise to the largest flow loss and drag.The cowl-lip blunted by the other two blunting manners is subjected to the shock interference pattern that transits with an increase in the blunting radius.Accordingly,the peak heat flux does not fall monotonously with the blunting radius increasing.Moreover,the cowl-lip surface suffers from severe aerothermal load when the shear layer or the supersonic jet impinges on the wall.展开更多
文摘Al-Zn-Mg alloys with different Zn/Mg mass ratios were evaluated as sacrificial anodes for cathodic protection of carbon steel in 3.5 wt.%Na Cl solution.The anodes were fabricated from pure Al,Zn and Mg metals using casting technique.Optical microscopy,SEM-EDS,XRD and electrochemical techniques were used.The results indicated that with decreasing Zn/Mg mass ratio,the grain size ofα(Al)and the particle size of the precipitates decreased while the volume fraction of the precipitates increased.The anode with Zn/Mg mass ratio>4.0 exhibited the lowest corrosion rate,while the anode with Zn/Mg mass ratio<0.62 gave the highest corrosion rate and provided the highest cathodic protection efficiency for carbon steel(AISI 1018).Furthermore,the results showed that the anode with Zn/Mg mass ratio<0.62 exhibited a porous corrosion product compared to the other anodes.
基金supported by the National Key Research and Development Program of China administrated by the Ministry of Science and Technology of China(2016YFB0401702)the National Natural Science Foundation of China(61674074,61704072 and61405089)+11 种基金Shenzhen Innovation Project(JCYJ20160301113537474)Shenzhen Basic Research Project(JCYJ20170817112012493)Development and Reform Commission of Shenzhen Project([2017]1395)Shenzhen Peacock Team Project(KQTD2016030111203005)Shenzhen Key Laboratory for Advanced Quantum Dot Displays and Lighting(ZDSYS201707281632549)Guangdong University Key Laboratory for Advanced Quantum Dot Displays and Lighting(2017KSYS007)Distinguished Young Scholar of National Natural Science Foundation of Guangdong(2017B030306010)Tianjin Zhonghuan Quantum Tech Co.,Ltd.(18YFZCGX00580)the start-up fund from Southern University of Science and Technologysupported by the Pico Center at SUSTech that received support from Presidential fundDevelopment and Reform Commission of Shenzhen MunicipalityChina Postdoctoral Science Foundation Grant(2018M631443)
文摘A highly pixelated and luminescent silica-coated quantum dot color filter(QDCF)was achieved by surface conjugation with epoxy functional group.Epoxy-functionalized silica-coated quantum dots(QDs)can be thoroughly mixed with SU-8 photoresist up to 25 wt.%without aggregation.The quantum yield(QY)of the silica-coated QDCF can be significantly improved from 19.3%to 36.5%after epoxy treatment.The pristine QDCF experienced a 40%QY decrease,while the epoxied silica-coated QDCF maintained its luminescence even after irradiation(300 mW cm 2@450 nm)for over 25 days.The well-controlled epoxy cap plays a critical role in attaining the ideal optical properties of the QDCF.
基金supported by the National Natural Science Foundation of China(Grant Nos.90716014 and 91216115)
文摘Under hypersonic flight conditions,the sharp cowl-lip leading edges have to be blunted because of the severe aerodynamic heating.This paper proposes four cowl-lip blunting methods and studies the corresponding flow characteristics and performances of the generic hypersonic inlets by numerical simulation under the design conditions of a flight Mach number of 6 and an altitude of 26 km.The results show that the local shock interference patterns in the vicinity of the blunted cowl-lips have a substantial influence on the flow characteristics of the hypersonic inlets even though the blunting radius is very small,which contribute to a pronounced degradation of the inlet performance.The Equal Length blunting Manner(ELM)is the most optimal in that a nearly even reflection of the ramp shock produces an approximately straight and weak cowl reflection shock.The minimal total pressure loss,the lowest cowl drag,maximum mass-capture and the minimal aeroheating are achieved for the hypersonic inlet.For the other blunting manners,the ramp shock cannot reflect evenly and produces more curved cowl reflection shock.The Type V shock interference pattern occurs for the Cross Section Cutting blunting Manner(CSCM)and the strongest cowl reflection shock gives rise to the largest flow loss and drag.The cowl-lip blunted by the other two blunting manners is subjected to the shock interference pattern that transits with an increase in the blunting radius.Accordingly,the peak heat flux does not fall monotonously with the blunting radius increasing.Moreover,the cowl-lip surface suffers from severe aerothermal load when the shear layer or the supersonic jet impinges on the wall.
