The degradation behaviors of the as-extruded and solution treated Mg-3Zn-xAg(x=0,1,3,mass fraction,%)alloys,as well as as-extruded pure Mg,have been investigated by immersion tests in simulated body fluid(SBF)at37...The degradation behaviors of the as-extruded and solution treated Mg-3Zn-xAg(x=0,1,3,mass fraction,%)alloys,as well as as-extruded pure Mg,have been investigated by immersion tests in simulated body fluid(SBF)at37°C.The as-extruded Mg-Zn(-Ag)alloys contained Mg51Zn20and Ag17Mg54.While the quasi-single phase Mg-Zn(-Ag)alloys were obtained by solution treatment at400°C for8h.The quasi-single phase Mg-Zn(-Ag)alloys showed lower degradation rate and more homogeneous degradation than corresponding as-extruded Mg alloys.Degradation rate of solid-solution treated Mg-3Zn-1Ag and Mg-3Zn-3Ag was approximately half that of corresponding as-extruded Mg alloy.Moreover,the degradation rate of solid-solution treated Mg-3Zn and Mg-3Zn-1Ag was equivalent to that of as-extruded pure Mg.However,heterogeneous degradation also occurred in quasi-single phase Mg-Zn-Ag alloys,compared to pure Mg.So,preparing complete single-phase Mg alloys could be a potential and feasible way to improve the corrosion resistance.展开更多
Zn plays an important role in the protection of iron and steel from corrosion in sea water, and the alloying of Zn and Ni can improve its corrosion resistance. The corrosion behavior of Zn？Ni alloys in synthetic sea ...Zn plays an important role in the protection of iron and steel from corrosion in sea water, and the alloying of Zn and Ni can improve its corrosion resistance. The corrosion behavior of Zn？Ni alloys in synthetic sea water （3.5% NaCl, mass fraction） was studied using Tafel plot and electrochemical impedance spectroscopy （EIS） techniques. The corrosion resistance of the investigated alloys with various Ni contents （0.5%？10%, mass fraction） was compared with that of Zn. The results show that the corrosion resistance of Zn？Ni alloys （except 0.5% Ni） is superior to that of Zn. The 10% Ni gives the highest corrosion resistance due to the formation ofγ-Zn3Ni withγ-ZnNi phases in the alloy. In the case of alloy I （0.5% Ni）, it exhibits a higher corrosion rate （less corrosion resistance） than Zn.展开更多
[Objective] The aim was to study the differences of tolerance and cultivate effect of Zn pollution in three vegetables in central China. [Method] Seed germination tests and pot experiments of radish （Raphanus Sativus...[Objective] The aim was to study the differences of tolerance and cultivate effect of Zn pollution in three vegetables in central China. [Method] Seed germination tests and pot experiments of radish （Raphanus Sativus L.）,pakchoi（Brassica campestris ssp. Chinensis） and edible amaranth （Amaranthus mangostanus） under Zn stress with different concentrations were carried out,to study the effects of different treatments on seed germination rates,seedling growth,biomass and Zn contents of vegetables. [Result] Zn stress with concentration of 2 000 mg/L had no significant influence on seed germination rates of pakchoi and radish,but had significant influences on seed germination rate of amaranth. Zn stress with concentrations of 500 and 2 000 mg/L had significant influence on seedling growth of the three vegetables. The tolerance of radish to excessive Zn toxicity was stronger than that of pakchoi and amaranth. In addition,Zn contents in edible part of the 3 vegetables in each treatment were lower than standard of food hygiene of China. When the added Zn was 100-1 000 mg/kg soil,the Zn contents in radish shoot and root parts were both lower than that in pakchoi and amaranth. [Conclusion] Radish had better tolerance on Zn pollution than pakchoi and amaranth,and was more suitable to be planted in Zn-contaminated soils than the other two vegetables in central China to reduce Zn contamination risk in food chain.展开更多
基金Projects(51371046,51525101,U1610253)supported by the National Natural Science Foundation of ChinaProject(NECT-12-0109)supported by the Program for New Century Excellent Talents in University,China+1 种基金Projects(N130510002,N141008001)supported by the Fundamental Research Funds for the Central Universities,ChinaProject supported by the Doctoral Thesis Cultivation Program of Northeastern University,China
文摘The degradation behaviors of the as-extruded and solution treated Mg-3Zn-xAg(x=0,1,3,mass fraction,%)alloys,as well as as-extruded pure Mg,have been investigated by immersion tests in simulated body fluid(SBF)at37°C.The as-extruded Mg-Zn(-Ag)alloys contained Mg51Zn20and Ag17Mg54.While the quasi-single phase Mg-Zn(-Ag)alloys were obtained by solution treatment at400°C for8h.The quasi-single phase Mg-Zn(-Ag)alloys showed lower degradation rate and more homogeneous degradation than corresponding as-extruded Mg alloys.Degradation rate of solid-solution treated Mg-3Zn-1Ag and Mg-3Zn-3Ag was approximately half that of corresponding as-extruded Mg alloy.Moreover,the degradation rate of solid-solution treated Mg-3Zn and Mg-3Zn-1Ag was equivalent to that of as-extruded pure Mg.However,heterogeneous degradation also occurred in quasi-single phase Mg-Zn-Ag alloys,compared to pure Mg.So,preparing complete single-phase Mg alloys could be a potential and feasible way to improve the corrosion resistance.
文摘Zn plays an important role in the protection of iron and steel from corrosion in sea water, and the alloying of Zn and Ni can improve its corrosion resistance. The corrosion behavior of Zn？Ni alloys in synthetic sea water （3.5% NaCl, mass fraction） was studied using Tafel plot and electrochemical impedance spectroscopy （EIS） techniques. The corrosion resistance of the investigated alloys with various Ni contents （0.5%？10%, mass fraction） was compared with that of Zn. The results show that the corrosion resistance of Zn？Ni alloys （except 0.5% Ni） is superior to that of Zn. The 10% Ni gives the highest corrosion resistance due to the formation ofγ-Zn3Ni withγ-ZnNi phases in the alloy. In the case of alloy I （0.5% Ni）, it exhibits a higher corrosion rate （less corrosion resistance） than Zn.
基金Supported by National Natural Science Foundation of China(40801115 )Science and Technology Projects in Guangdong Province(2006A20601001)~~
文摘[Objective] The aim was to study the differences of tolerance and cultivate effect of Zn pollution in three vegetables in central China. [Method] Seed germination tests and pot experiments of radish （Raphanus Sativus L.）,pakchoi（Brassica campestris ssp. Chinensis） and edible amaranth （Amaranthus mangostanus） under Zn stress with different concentrations were carried out,to study the effects of different treatments on seed germination rates,seedling growth,biomass and Zn contents of vegetables. [Result] Zn stress with concentration of 2 000 mg/L had no significant influence on seed germination rates of pakchoi and radish,but had significant influences on seed germination rate of amaranth. Zn stress with concentrations of 500 and 2 000 mg/L had significant influence on seedling growth of the three vegetables. The tolerance of radish to excessive Zn toxicity was stronger than that of pakchoi and amaranth. In addition,Zn contents in edible part of the 3 vegetables in each treatment were lower than standard of food hygiene of China. When the added Zn was 100-1 000 mg/kg soil,the Zn contents in radish shoot and root parts were both lower than that in pakchoi and amaranth. [Conclusion] Radish had better tolerance on Zn pollution than pakchoi and amaranth,and was more suitable to be planted in Zn-contaminated soils than the other two vegetables in central China to reduce Zn contamination risk in food chain.
