Magnesium and its alloys have attracting rising attention as one of biodegradable metallic materials.However,the rapid corrosion and severe localized corrosion still hinder their extensive applications in clinics.In t...Magnesium and its alloys have attracting rising attention as one of biodegradable metallic materials.However,the rapid corrosion and severe localized corrosion still hinder their extensive applications in clinics.In this study,micro-alloying of Ca(≤0.1 wt%)into Mg0.5Zn0.2Ge alloy developed in our previous work was explored to further enhance the corrosion resistance and alleviate the localized corrosion of the alloy.The results reveal that the addition of Ca leads to the transformation of the cathodic Mg_(2)Ge phase in Mg0.5Zn0.2Ca alloy into anodic MgCaGe phase in Ca-containing alloys,thereby changing the galvanic couples in alloys during immersion.The preferential dissolution of MgCaGe phase promotes the participation of Ca and Ge into the formation of corrosion products,resulting in the enrichment of Ca and Ge in the outmost of corrosion product layer,which stabilizes and passivates the corrosion product layer on Mg alloy surface.Additionally,the enrichment of Zn at the corrosion interface seems to further hinder the corrosion of Mg matrix.All of these factors confer a slower and more uniform corrosion on Mg0.5Zn0.2GexCa(x<0.1 wt%)alloy,which provides favorable candidates for the further processing to gain suitable biodegradable Mg alloys.展开更多
The degradation behavior of biodegradable Mg alloys has become a research hotspot in the fields about biodegradable metallic materials.While the most of the related publications mainly focused on the degradation rate ...The degradation behavior of biodegradable Mg alloys has become a research hotspot in the fields about biodegradable metallic materials.While the most of the related publications mainly focused on the degradation rate of Mg-based materials,but rare to care about the changes of their mechanical properties during the immersion period,which can significantly affect their service performance.The link between residual strength and Mg degradation is not appreciated enough.In this work,a series media were constructed based on Hanks’solution,the effects of inorganic ions on the degradation rate and mechanical integrity of Mg-Zn-Y-Nd alloy were investigated.The results indicated that the degradation behavior of Mg alloy was mainly controlled by degradation products and there is no direct correspondence between the degradation rate change and mechanical integrity of Mg alloy.The relevant findings are beneficial for selecting the monitoring index in Mg corrosion tests and evaluating the service reliability of Mg alloys for biomedical applications.展开更多
When zero-valent iron(ZVI)is prepared and applied under neutral conditions,it is easy to form oxides or hydroxides on its surface,which hinders the electron release of ZVI.To this end,a nucleophile was introduced into...When zero-valent iron(ZVI)is prepared and applied under neutral conditions,it is easy to form oxides or hydroxides on its surface,which hinders the electron release of ZVI.To this end,a nucleophile was introduced into the ZVI system to inhibit the precipitation of iron ions,improve the conductivity of the solution,and promote the removal efficiency of electrophilic functional groups in organic compounds.In this study,the addition of nucleophiles such as ethylenediamine,methylamine and dimethylamine to the ZVI/H_(2)O_(2)system resulted in an enhanced removal efficiency of tetracycline(TC)under neutral condition,while electrophiles such as EDTA-2Na and oxalic acid dihydrate impeded the removal of TC.Experimental results demonstrated that the presence of nucleophiles could effectively promote the release of iron ions and increase the proportion of ferrous in both aqueous solution and solid surface of ZVI.Experimental and theoretical calculation results revealed that the electrophilic functional group was eliminated in the TC molecule,and the toxicity of the treated solution was reduced significantly.Overall,this work provides a selection of the conditions and pollutants applicable to ZVI under neutral pH conditions.展开更多
In this paper,a dynamic flow-regulation algorithm-oriented network overload control is proposed.It can proportion-ally distribute the load between the high-degree nodes and the low-degree nodes.According to the theore...In this paper,a dynamic flow-regulation algorithm-oriented network overload control is proposed.It can proportion-ally distribute the load between the high-degree nodes and the low-degree nodes.According to the theoretical analysis,the net-work transmission performance of the proposed algorithm is in inverse proportion to the usage rate of the high-degree nodes.Simulations show that the new algorithm is more flexible and can enhance the network capability in most circumstances compared with the shortest path routing algorithm.Moreover,the compari-son with the efficient routing algorism also reveals the prominent performance of the new algorithm.展开更多
Correction to:Acta Metallurgica Sinica(English Letters)https://doi.org/10.1007/s40195-024-01703-2 In the original publication,the author name has been inadvertently appeared with a spell error as Bishan Chen.The corre...Correction to:Acta Metallurgica Sinica(English Letters)https://doi.org/10.1007/s40195-024-01703-2 In the original publication,the author name has been inadvertently appeared with a spell error as Bishan Chen.The corrected name should appear as Bishan Cheng.The original article has been corrected.展开更多
基金supported by the Natural Science Foundation of Henan Provincial(222300420309)the China Postdoctoral Science Foundation(2022M710132)+1 种基金the Henan Postdoctoral Foundation(202102006)the Startup Research Fund of Zhengzhou University(32340146).
文摘Magnesium and its alloys have attracting rising attention as one of biodegradable metallic materials.However,the rapid corrosion and severe localized corrosion still hinder their extensive applications in clinics.In this study,micro-alloying of Ca(≤0.1 wt%)into Mg0.5Zn0.2Ge alloy developed in our previous work was explored to further enhance the corrosion resistance and alleviate the localized corrosion of the alloy.The results reveal that the addition of Ca leads to the transformation of the cathodic Mg_(2)Ge phase in Mg0.5Zn0.2Ca alloy into anodic MgCaGe phase in Ca-containing alloys,thereby changing the galvanic couples in alloys during immersion.The preferential dissolution of MgCaGe phase promotes the participation of Ca and Ge into the formation of corrosion products,resulting in the enrichment of Ca and Ge in the outmost of corrosion product layer,which stabilizes and passivates the corrosion product layer on Mg alloy surface.Additionally,the enrichment of Zn at the corrosion interface seems to further hinder the corrosion of Mg matrix.All of these factors confer a slower and more uniform corrosion on Mg0.5Zn0.2GexCa(x<0.1 wt%)alloy,which provides favorable candidates for the further processing to gain suitable biodegradable Mg alloys.
基金support from the Na-tional Key Research and Development Program of China(2021YFC2400703)the Key Projects of the Joint Fund of the National Natural Science Foundation of China(U1804251)support from Natural Science Foundation of Henan Provincial(222300420309).
文摘The degradation behavior of biodegradable Mg alloys has become a research hotspot in the fields about biodegradable metallic materials.While the most of the related publications mainly focused on the degradation rate of Mg-based materials,but rare to care about the changes of their mechanical properties during the immersion period,which can significantly affect their service performance.The link between residual strength and Mg degradation is not appreciated enough.In this work,a series media were constructed based on Hanks’solution,the effects of inorganic ions on the degradation rate and mechanical integrity of Mg-Zn-Y-Nd alloy were investigated.The results indicated that the degradation behavior of Mg alloy was mainly controlled by degradation products and there is no direct correspondence between the degradation rate change and mechanical integrity of Mg alloy.The relevant findings are beneficial for selecting the monitoring index in Mg corrosion tests and evaluating the service reliability of Mg alloys for biomedical applications.
基金financial support from Sichuan Science and Technology Program(No.2023NSFSC0345)the Fundamental Research Funds for the Central Universities(Southwest Minzu University,No.ZYN2022002)+1 种基金the Innovation Scientific Research Program for Graduates of Southwest Minzu University(Southwest Minzu University,No.3300222156)the China Scholarship Council(No.202008510077)。
文摘When zero-valent iron(ZVI)is prepared and applied under neutral conditions,it is easy to form oxides or hydroxides on its surface,which hinders the electron release of ZVI.To this end,a nucleophile was introduced into the ZVI system to inhibit the precipitation of iron ions,improve the conductivity of the solution,and promote the removal efficiency of electrophilic functional groups in organic compounds.In this study,the addition of nucleophiles such as ethylenediamine,methylamine and dimethylamine to the ZVI/H_(2)O_(2)system resulted in an enhanced removal efficiency of tetracycline(TC)under neutral condition,while electrophiles such as EDTA-2Na and oxalic acid dihydrate impeded the removal of TC.Experimental results demonstrated that the presence of nucleophiles could effectively promote the release of iron ions and increase the proportion of ferrous in both aqueous solution and solid surface of ZVI.Experimental and theoretical calculation results revealed that the electrophilic functional group was eliminated in the TC molecule,and the toxicity of the treated solution was reduced significantly.Overall,this work provides a selection of the conditions and pollutants applicable to ZVI under neutral pH conditions.
基金Supported by the National Natural Science Foundation of China (60970114 , 41104010)the National Natural Science Foundation of Hubei Province (ZRZ0041)+2 种基金the Science and Technology Project of Wuhan City (201110921292)the Open Fund of the Ministry of Public Security of the Information Network Security Key Laboratory (C10607)the Independent Scientific Research Projects of the Wuhan University Graduate Student (201121102020002)
文摘In this paper,a dynamic flow-regulation algorithm-oriented network overload control is proposed.It can proportion-ally distribute the load between the high-degree nodes and the low-degree nodes.According to the theoretical analysis,the net-work transmission performance of the proposed algorithm is in inverse proportion to the usage rate of the high-degree nodes.Simulations show that the new algorithm is more flexible and can enhance the network capability in most circumstances compared with the shortest path routing algorithm.Moreover,the compari-son with the efficient routing algorism also reveals the prominent performance of the new algorithm.
文摘Correction to:Acta Metallurgica Sinica(English Letters)https://doi.org/10.1007/s40195-024-01703-2 In the original publication,the author name has been inadvertently appeared with a spell error as Bishan Chen.The corrected name should appear as Bishan Cheng.The original article has been corrected.
