Fluorescence detecting both organic and inorganic analytes has aroused tremendous scientific interests, because fluorescence techniques have high sensitivity and are easy to operate. A new threedimensional(3D) MOF {[(...Fluorescence detecting both organic and inorganic analytes has aroused tremendous scientific interests, because fluorescence techniques have high sensitivity and are easy to operate. A new threedimensional(3D) MOF {[(CH_(3))_(2)NH_(2)][Zn_(3)(bbip)(BTDI)1.5(OH)]·DMF·MeOH·3H_(2)O}n(JXUST-13, bbip = 2,6-bis(benzimidazol-1-yl)pyridine and H_(4)BTDI = 5,5-(benzo[c][1,2,5]thiadiazole-4,7-diyl)diisophthalic acid)with new 4,4,8-connceted topology has been successfully synthesized and structurally characterized. Importantly, JXUST-13 could recognize H_(2)PO_(4)-and acetylacetone(Acac) by obvious fluorescence blue shift and slight enhancement with the detection limits of 2.70 μmol/L and 0.21 mmol/L, respectively. In addition, JXUST-13 exhibits relatively good thermal stability, chemical stabilities as well as reusability, and the analytes could be distinguished by naked eye and fluorescence test paper. Remarkably, JXUST-13 is the first dual-responsive MOF sensor based on fluorescence blue shift for the detection of H_(2)PO_(4)-and Acac with good selectivity in a handy, economic, and environmentally friendly manner.展开更多
Cancer cells often upregulate nutrient transporters to fulfill their increased biosynthetic and bioenergetic needs,and to maintain redox homeostasis.One nutrient transporter frequently overexpressed in human cancers i...Cancer cells often upregulate nutrient transporters to fulfill their increased biosynthetic and bioenergetic needs,and to maintain redox homeostasis.One nutrient transporter frequently overexpressed in human cancers is the cystine/glutamate antiporter solute carrier family 7 member 11(SLC7A11;also known as xCT).SLC7A11 promotes cystine uptake and glutathione biosynthesis,resulting in protection from oxidative stress and ferroptotic cell death.Recent studies have unexpectedly revealed that SLC7A11 also plays critical roles in glutamine metabolism and regulates the glucose and glutamine dependency of cancer cells.This review discusses the roles of SLC7A11 in regulating the anti-oxidant response and nutrient dependency of cancer cells,explores our current understanding of SLC7A11 regulation in cancer metabolism,and highlights key open questions for future studies in this emerging research area.A deeper understanding of SLC7A11 in cancer metabolism may identify new therapeutic opportunities to target this important amino acid transporter for cancer treatment.展开更多
The Zn,Cu,and Sc contents of 7xxx Al alloys were adjusted according to the chemical composition of a 7085 Al alloy,and the effects of Zn and Cu contents and Sc addition on the microstructures,hardness,and quench sensi...The Zn,Cu,and Sc contents of 7xxx Al alloys were adjusted according to the chemical composition of a 7085 Al alloy,and the effects of Zn and Cu contents and Sc addition on the microstructures,hardness,and quench sensitivity of the 7xxx Al alloys were studied.The alloys with high Zn content and Sc addition exhibited higher hardness than the 7085 alloy at the position 3 mm away from the quenching end.The density ofηand T phases increased with the increase in Zn and Cu contents,and the Sc addition led to the formation of the Y phase and moreηphases at the position 120 mm away from the quenching end.Compared with the 7085 alloy,the high Zn−high Cu and Sc-added alloys exhibited higher quench sensitivity,while the simultaneous increase in Zn content and decrease in Cu content could enhance the hardness and reduce the quench sensitivity of the 7085 alloy.展开更多
Research and development of the ideal artificial bone-substitute materials to replace autologous and allogeneic bones for repairing bone defects is still a challenge in clinical orthopedics.Recently,poly(lactic-co-gly...Research and development of the ideal artificial bone-substitute materials to replace autologous and allogeneic bones for repairing bone defects is still a challenge in clinical orthopedics.Recently,poly(lactic-co-glycolic acid)(PLGA)-based artificial bone-substitute materials are attracting increasing attention as the benefit of their suitable biocompatibility,degradability,mechanical properties,and capabilities to promote bone regeneration.In this article,we comprehensively review the artificial bone-substitute materials made from PLGA or the composites of PLGA and other organic and inorganic substances,elaborate on their applications for bone regeneration with or without bioactive factors,and prospect the challenges and opportunities in clinical bone regeneration.展开更多
针对并网级联型电池储能系统的电池荷电状态(State of Charge,SOC)不均衡问题,提出了一种基于改进下垂控制的电池组SOC均衡策略。该策略在传统下垂控制基础上,通过考虑各电池组SOC实时估计信息,在不影响正常功率输出并保持与电网同步的...针对并网级联型电池储能系统的电池荷电状态(State of Charge,SOC)不均衡问题,提出了一种基于改进下垂控制的电池组SOC均衡策略。该策略在传统下垂控制基础上,通过考虑各电池组SOC实时估计信息,在不影响正常功率输出并保持与电网同步的前提下,引入分配修正项来实时优化分配各级联模块的有功功率和电压幅值参考,实现各级联模块的SOC均衡。通过调整分配修正系数,调节各级联模块输出功率差异,从而控制电池组的SOC均衡速度。采用奇异理论分析了该控制策略的稳定性,给出了控制参数的设计依据。不同工况下级联型储能系统的仿真结果,验证了所提控制策略及其理论分析的正确性和有效性。展开更多
In order to verify the feasibility of producing Mg−rare earth(RE)alloy by selective laser melting(SLM)process,the microstructure and mechanical properties of Mg−15Gd−1Zn−0.4Zr(wt.%)(GZ151K)alloy were investigated.The ...In order to verify the feasibility of producing Mg−rare earth(RE)alloy by selective laser melting(SLM)process,the microstructure and mechanical properties of Mg−15Gd−1Zn−0.4Zr(wt.%)(GZ151K)alloy were investigated.The results show that fine grains(~2μm),fine secondary phases and weak texture,were observed in the as-fabricated(SLMed)GZ151K Mg alloy.At room temperature,the SLMed GZ151K alloy has a yield strength(YS)of 345 MPa,ultimate tensile strength(UTS)of 368 MPa and elongation of 3.0%.After subsequent aging(200℃,64 h,T5 treatment),the YS,UTS and elongation of the SLMed-T5 alloy are 410 MPa,428 MPa and 3.4%,respectively,which are higher than those of the conventional cast-T6 alloy,especially with the YS increased by 122 MPa.The main strengthening mechanisms of the SLMed GZ151K alloy are fine grains,fine secondary phases and residual stress,while after T5 treatment,the YS of the alloy is further enhanced by precipitates.展开更多
To restore the natural nitrogen cycle(N-cycle),artificial N-cycle electrocatalysis with flexibility,sustainability,and compatibility can convert intermittent renewable energy(e.g.,wind)to harmful or value-added chemic...To restore the natural nitrogen cycle(N-cycle),artificial N-cycle electrocatalysis with flexibility,sustainability,and compatibility can convert intermittent renewable energy(e.g.,wind)to harmful or value-added chemicals with minimal carbon emissions.The background of such N-cycles,such as nitrogen fixation,ammonia oxidation,and nitrate reduction,is briefly introduced here.The discussion of emerging nanostructures in various conversion reactions is focused on the architecture/compositional design,electrochemical performances,reaction mechanisms,and instructive tests.Energy device advancements for achieving more functions as well as in situ/operando characterizations toward understanding key steps are also highlighted.Furthermore,some recently proposed reactions as well as less discussed C-N coupling reactions are also summarized.We classify inorganic nitrogen sources that convert to each other under an applied voltage into three types,namely,abundant nitrogen,toxic nitrate(nitrite),and nitrogen oxides,and useful compounds such as ammonia,hydrazine,and hydroxylamine,with the goal of providing more critical insights into strategies to facilitate the development of our circular nitrogen economy.展开更多
Trace amount of Sr(0.05 wt.%)was added into the hypoeutectic Al−Si(3−12 wt.%Si)alloys to modify their microstructure and improve thermal conductivity.The results showed that the thermal conductivity of hypoeutectic Al...Trace amount of Sr(0.05 wt.%)was added into the hypoeutectic Al−Si(3−12 wt.%Si)alloys to modify their microstructure and improve thermal conductivity.The results showed that the thermal conductivity of hypoeutectic Al−Si alloys was improved by Sr modification,and the increment and increasing rate of the thermal conductivity gradually increased with Si content increasing.The improvement of thermal conductivity was primarily related to the morphology variation of eutectic Si phases.In Sr-modified Al−Si alloys,the morphology of eutectic Si phases was a mixed morphology of fiber structure and fine flaky structure,and the proportion of the fine flaky eutectic Si phases gradually decreased with Si content increasing.Under the Si content reaching 9 wt.%,the proportion of fine flaky eutectic Si phases was nearly negligible in Sr-modified alloys.Correspondingly,the increment and increasing rate of thermal conductivity of Sr-modified alloys reached the maximum and tended to be stable.展开更多
A novel extrusion-shearing(ES) composite process was designed to fabricate fine-grained, high strength and tough magnesium alloy. The structural parameters of an ES die were optimized by conducting an orthogonal simul...A novel extrusion-shearing(ES) composite process was designed to fabricate fine-grained, high strength and tough magnesium alloy. The structural parameters of an ES die were optimized by conducting an orthogonal simulation experiment using finite element software Deform-3D, and Mg-3 Zn-0.6 Ca-0.6 Zr(ZXK310) alloy was processed using the ES die. The results show that the optimized structural parameters of ES die are extrusion angle(α) of 90°, extrusion section height(h) of 15 mm and inner fillet radius(r) of 10 mm. After ES at an extrusion temperature and a die temperature of 350 °C, ZXK310 alloy exhibited good ES forming ability, and obvious dynamic recrystallization occurred in the forming area. The grain size decreased from 1.42 μm of extrusion area to 0.85 μm of the forming area. Owing to the pinning of second phase and formation of ultrafine grains, the tensile strength, yield strength and elongation of alloy reached 362 MPa, 289 MPa and 21.7%, respectively.展开更多
The surface hydrophobization and flotation of a xanthate−hydroxamate collector toward copper oxide mineral were compared with the combined collectors of xanthate and hydroxamate through water contact angle(WCA)and mic...The surface hydrophobization and flotation of a xanthate−hydroxamate collector toward copper oxide mineral were compared with the combined collectors of xanthate and hydroxamate through water contact angle(WCA)and micro-flotation experiments.The results showed that S-[(2-hydroxyamino)-2-oxoethyl]-O-octyl-dithiocarbonate ester(HAOODE)exhibited stronger hydrophobization and better flotation performance to malachite(Cu2(OH)2CO3)than octyl-hydroxamic acid(OHA)and its combination with S-allyl-O-ethyl xanthate ester(AEXE).To understand the hydrophobic intensification mechanism of HAOODE to malachite,zeta potential,atomic force microscopy(AFM)and XPS measurements were carried out.The results recommended that malachite chemisorbed HAOODE to form Cu—HAOODE complexes in which the hydroxamate—(O,O)—Cu and—O—C(—S—Cu)—S—configurations co-existed.The co-adsorption of HAOODE’s hetero-difunctional groups was more stable than the single-functionalgroup adsorption of OHA and AEXE,which produced the“loop”structure and intensified the self-assembly alignment of HAOODE on malachite surfaces.In addition,the“h”shape steric orientation of the double hydrophobic groups in HAOODE facilitated stronger hydrophobization toward malachite than the“line”or“V”hydrophobic carbon chains of OHA or AEXE.Thus,HAOODE achieved the preferable flotation recovery of malachite particles in comparison with OHA and AEXE.展开更多
The microstructure,mechanical properties and corrosion behavior of quaternary degradable Mg−1Zn−0.2Ca−xAg(x=1,2,4 wt.%)alloy wires,intended as anastomotic nails,were investigated.It was found that these Ag-containing ...The microstructure,mechanical properties and corrosion behavior of quaternary degradable Mg−1Zn−0.2Ca−xAg(x=1,2,4 wt.%)alloy wires,intended as anastomotic nails,were investigated.It was found that these Ag-containing alloy wires mainly consist of Mg matrix and Ag17Mg54 phase,characterized by SEM,EDS,XRD and TEM.Tensile and knotting tests results demonstrate the superior mechanical properties of these alloy wires.Especially,Mg−1Zn−0.2Ca−4Ag alloy exhibits the highest mechanical properties,i.e.an ultimate tensile strength of 334 MPa and an elongation of 8.6%.Moreover,with increasing Ag content,the corrosion rates of these alloy wires remarkably increase due to the formation of more micro-galvanic coupling between Mg matrix and Ag17Mg54 phase,shown by mass loss and scanning Kelvin probe force microscopy(SKPFM)results.The present alloy can be completely degraded within 28 d,satisfying the property requirements of anastomotic nails.展开更多
基金supported by the National Natural Science Foundation of China (Nos. 22061019, 21861018, 22161019 and 12174172)the NSF of Jiangxi Province (No. 20202ACBL213001)+4 种基金Jiangxi Provincial Key Laboratory of Functional Molecular Materials Chemistry(No. 20212BCD42018)Fujian Key Laboratory of Functional Marine Sensing Materials,Minjiang University (No. MJUKF-FMSM202010)the Youth Jinggang Scholars Program in Jiangxi Province (No.QNJG2019053)the Two Thousand Program in Jiangxi Province (No.jxsq2019201068)the Special Foundation for Postgraduate Innovation in Jiangxi Province (No. YC_(2)020-B155)。
文摘Fluorescence detecting both organic and inorganic analytes has aroused tremendous scientific interests, because fluorescence techniques have high sensitivity and are easy to operate. A new threedimensional(3D) MOF {[(CH_(3))_(2)NH_(2)][Zn_(3)(bbip)(BTDI)1.5(OH)]·DMF·MeOH·3H_(2)O}n(JXUST-13, bbip = 2,6-bis(benzimidazol-1-yl)pyridine and H_(4)BTDI = 5,5-(benzo[c][1,2,5]thiadiazole-4,7-diyl)diisophthalic acid)with new 4,4,8-connceted topology has been successfully synthesized and structurally characterized. Importantly, JXUST-13 could recognize H_(2)PO_(4)-and acetylacetone(Acac) by obvious fluorescence blue shift and slight enhancement with the detection limits of 2.70 μmol/L and 0.21 mmol/L, respectively. In addition, JXUST-13 exhibits relatively good thermal stability, chemical stabilities as well as reusability, and the analytes could be distinguished by naked eye and fluorescence test paper. Remarkably, JXUST-13 is the first dual-responsive MOF sensor based on fluorescence blue shift for the detection of H_(2)PO_(4)-and Acac with good selectivity in a handy, economic, and environmentally friendly manner.
基金supported by the Andrew Sabin Family Fellow Award and Institutional Research Grant from the University of Texas MD Anderson Cancer Center,Grants from National Institutes of Health(CA181196 and CA190370)Anna Fuller Fund,and Ellison Medical Foundation(AG-NS-0973-13).
文摘Cancer cells often upregulate nutrient transporters to fulfill their increased biosynthetic and bioenergetic needs,and to maintain redox homeostasis.One nutrient transporter frequently overexpressed in human cancers is the cystine/glutamate antiporter solute carrier family 7 member 11(SLC7A11;also known as xCT).SLC7A11 promotes cystine uptake and glutathione biosynthesis,resulting in protection from oxidative stress and ferroptotic cell death.Recent studies have unexpectedly revealed that SLC7A11 also plays critical roles in glutamine metabolism and regulates the glucose and glutamine dependency of cancer cells.This review discusses the roles of SLC7A11 in regulating the anti-oxidant response and nutrient dependency of cancer cells,explores our current understanding of SLC7A11 regulation in cancer metabolism,and highlights key open questions for future studies in this emerging research area.A deeper understanding of SLC7A11 in cancer metabolism may identify new therapeutic opportunities to target this important amino acid transporter for cancer treatment.
基金The authors are grateful for the financial supports from the Science and Technology Major Project of Guangxi,China(GKAA17202007).
文摘The Zn,Cu,and Sc contents of 7xxx Al alloys were adjusted according to the chemical composition of a 7085 Al alloy,and the effects of Zn and Cu contents and Sc addition on the microstructures,hardness,and quench sensitivity of the 7xxx Al alloys were studied.The alloys with high Zn content and Sc addition exhibited higher hardness than the 7085 alloy at the position 3 mm away from the quenching end.The density ofηand T phases increased with the increase in Zn and Cu contents,and the Sc addition led to the formation of the Y phase and moreηphases at the position 120 mm away from the quenching end.Compared with the 7085 alloy,the high Zn−high Cu and Sc-added alloys exhibited higher quench sensitivity,while the simultaneous increase in Zn content and decrease in Cu content could enhance the hardness and reduce the quench sensitivity of the 7085 alloy.
基金This study was financially supported by the National Natural Science Foundation of China(Grant Nos.51973216,51873207,51803006,and 51833010)the Science and Technology Development Program of Jilin Province(Grant No.20200404182YY)+1 种基金the Youth Innovation Promotion Association of the Chinese Academy of Sciences(Grant No.2019005)the State Key Laboratory of Advanced Technology for Materials Synthesis and Processing(Wuhan University of Technology)(Grant No.2020-KF-5).
文摘Research and development of the ideal artificial bone-substitute materials to replace autologous and allogeneic bones for repairing bone defects is still a challenge in clinical orthopedics.Recently,poly(lactic-co-glycolic acid)(PLGA)-based artificial bone-substitute materials are attracting increasing attention as the benefit of their suitable biocompatibility,degradability,mechanical properties,and capabilities to promote bone regeneration.In this article,we comprehensively review the artificial bone-substitute materials made from PLGA or the composites of PLGA and other organic and inorganic substances,elaborate on their applications for bone regeneration with or without bioactive factors,and prospect the challenges and opportunities in clinical bone regeneration.
文摘针对并网级联型电池储能系统的电池荷电状态(State of Charge,SOC)不均衡问题,提出了一种基于改进下垂控制的电池组SOC均衡策略。该策略在传统下垂控制基础上,通过考虑各电池组SOC实时估计信息,在不影响正常功率输出并保持与电网同步的前提下,引入分配修正项来实时优化分配各级联模块的有功功率和电压幅值参考,实现各级联模块的SOC均衡。通过调整分配修正系数,调节各级联模块输出功率差异,从而控制电池组的SOC均衡速度。采用奇异理论分析了该控制策略的稳定性,给出了控制参数的设计依据。不同工况下级联型储能系统的仿真结果,验证了所提控制策略及其理论分析的正确性和有效性。
基金financial supports from the National Key Research and Development Program of China(Nos.2016YFB0301000,2016YFB0701204)the National Natural Science Foundation of China(No.51821001).
文摘In order to verify the feasibility of producing Mg−rare earth(RE)alloy by selective laser melting(SLM)process,the microstructure and mechanical properties of Mg−15Gd−1Zn−0.4Zr(wt.%)(GZ151K)alloy were investigated.The results show that fine grains(~2μm),fine secondary phases and weak texture,were observed in the as-fabricated(SLMed)GZ151K Mg alloy.At room temperature,the SLMed GZ151K alloy has a yield strength(YS)of 345 MPa,ultimate tensile strength(UTS)of 368 MPa and elongation of 3.0%.After subsequent aging(200℃,64 h,T5 treatment),the YS,UTS and elongation of the SLMed-T5 alloy are 410 MPa,428 MPa and 3.4%,respectively,which are higher than those of the conventional cast-T6 alloy,especially with the YS increased by 122 MPa.The main strengthening mechanisms of the SLMed GZ151K alloy are fine grains,fine secondary phases and residual stress,while after T5 treatment,the YS of the alloy is further enhanced by precipitates.
基金This work was supported by the National Natural Science Foundation of China(No.21575137).
文摘To restore the natural nitrogen cycle(N-cycle),artificial N-cycle electrocatalysis with flexibility,sustainability,and compatibility can convert intermittent renewable energy(e.g.,wind)to harmful or value-added chemicals with minimal carbon emissions.The background of such N-cycles,such as nitrogen fixation,ammonia oxidation,and nitrate reduction,is briefly introduced here.The discussion of emerging nanostructures in various conversion reactions is focused on the architecture/compositional design,electrochemical performances,reaction mechanisms,and instructive tests.Energy device advancements for achieving more functions as well as in situ/operando characterizations toward understanding key steps are also highlighted.Furthermore,some recently proposed reactions as well as less discussed C-N coupling reactions are also summarized.We classify inorganic nitrogen sources that convert to each other under an applied voltage into three types,namely,abundant nitrogen,toxic nitrate(nitrite),and nitrogen oxides,and useful compounds such as ammonia,hydrazine,and hydroxylamine,with the goal of providing more critical insights into strategies to facilitate the development of our circular nitrogen economy.
基金Project(2013B090500091)supported by Industry-University-Research Combined Project of Guangdong Province,ChinaProject(20180358)supported by the Shenzhen Jiansheng Technology Inc.Cooperation Project,China。
文摘Trace amount of Sr(0.05 wt.%)was added into the hypoeutectic Al−Si(3−12 wt.%Si)alloys to modify their microstructure and improve thermal conductivity.The results showed that the thermal conductivity of hypoeutectic Al−Si alloys was improved by Sr modification,and the increment and increasing rate of the thermal conductivity gradually increased with Si content increasing.The improvement of thermal conductivity was primarily related to the morphology variation of eutectic Si phases.In Sr-modified Al−Si alloys,the morphology of eutectic Si phases was a mixed morphology of fiber structure and fine flaky structure,and the proportion of the fine flaky eutectic Si phases gradually decreased with Si content increasing.Under the Si content reaching 9 wt.%,the proportion of fine flaky eutectic Si phases was nearly negligible in Sr-modified alloys.Correspondingly,the increment and increasing rate of thermal conductivity of Sr-modified alloys reached the maximum and tended to be stable.
基金supported by Liaoning Revitalization Talents Program, China (XLYC1807021)Joint Research Fund of Liaoning - Shenyang National Laboratory for Materials Science, China (2019JH3/30100014)+1 种基金Innovation Talent Program in Sciences and Technologies for Young and Middle-aged Scientists of Shenyang, China (RC200414)Scientific Research Fund of Liaoning Provincial Department of Education, China (LJGD2020008)
文摘A novel extrusion-shearing(ES) composite process was designed to fabricate fine-grained, high strength and tough magnesium alloy. The structural parameters of an ES die were optimized by conducting an orthogonal simulation experiment using finite element software Deform-3D, and Mg-3 Zn-0.6 Ca-0.6 Zr(ZXK310) alloy was processed using the ES die. The results show that the optimized structural parameters of ES die are extrusion angle(α) of 90°, extrusion section height(h) of 15 mm and inner fillet radius(r) of 10 mm. After ES at an extrusion temperature and a die temperature of 350 °C, ZXK310 alloy exhibited good ES forming ability, and obvious dynamic recrystallization occurred in the forming area. The grain size decreased from 1.42 μm of extrusion area to 0.85 μm of the forming area. Owing to the pinning of second phase and formation of ultrafine grains, the tensile strength, yield strength and elongation of alloy reached 362 MPa, 289 MPa and 21.7%, respectively.
基金Project(51474253)supported by the National Natural Science Foundation of China。
文摘The surface hydrophobization and flotation of a xanthate−hydroxamate collector toward copper oxide mineral were compared with the combined collectors of xanthate and hydroxamate through water contact angle(WCA)and micro-flotation experiments.The results showed that S-[(2-hydroxyamino)-2-oxoethyl]-O-octyl-dithiocarbonate ester(HAOODE)exhibited stronger hydrophobization and better flotation performance to malachite(Cu2(OH)2CO3)than octyl-hydroxamic acid(OHA)and its combination with S-allyl-O-ethyl xanthate ester(AEXE).To understand the hydrophobic intensification mechanism of HAOODE to malachite,zeta potential,atomic force microscopy(AFM)and XPS measurements were carried out.The results recommended that malachite chemisorbed HAOODE to form Cu—HAOODE complexes in which the hydroxamate—(O,O)—Cu and—O—C(—S—Cu)—S—configurations co-existed.The co-adsorption of HAOODE’s hetero-difunctional groups was more stable than the single-functionalgroup adsorption of OHA and AEXE,which produced the“loop”structure and intensified the self-assembly alignment of HAOODE on malachite surfaces.In addition,the“h”shape steric orientation of the double hydrophobic groups in HAOODE facilitated stronger hydrophobization toward malachite than the“line”or“V”hydrophobic carbon chains of OHA or AEXE.Thus,HAOODE achieved the preferable flotation recovery of malachite particles in comparison with OHA and AEXE.
基金The authors are grateful for the financial supports from the National Natural Science Foundation of China(51671017 and 51971020)the Beijing Municipal Natural Science Foundation,China(2202033)+2 种基金Beijing Laboratory of Metallic Materials and Processing for Modern Transportation,China,the Fundamental Research Funds for the Central Universities,China(FRF-IC-19-015)the Major State Research and Development Program of China(2016YFB0300801)the Opening Research Fund of State Key Laboratory for Advanced Metals and Materials,China(2018-Z04).
文摘The microstructure,mechanical properties and corrosion behavior of quaternary degradable Mg−1Zn−0.2Ca−xAg(x=1,2,4 wt.%)alloy wires,intended as anastomotic nails,were investigated.It was found that these Ag-containing alloy wires mainly consist of Mg matrix and Ag17Mg54 phase,characterized by SEM,EDS,XRD and TEM.Tensile and knotting tests results demonstrate the superior mechanical properties of these alloy wires.Especially,Mg−1Zn−0.2Ca−4Ag alloy exhibits the highest mechanical properties,i.e.an ultimate tensile strength of 334 MPa and an elongation of 8.6%.Moreover,with increasing Ag content,the corrosion rates of these alloy wires remarkably increase due to the formation of more micro-galvanic coupling between Mg matrix and Ag17Mg54 phase,shown by mass loss and scanning Kelvin probe force microscopy(SKPFM)results.The present alloy can be completely degraded within 28 d,satisfying the property requirements of anastomotic nails.
