With the increasing attention received by lightweight metals,numerous essential fields have increased requirements for mag-nesium(Mg)alloys with good room-temperature and high-temperature mechanical properties.However...With the increasing attention received by lightweight metals,numerous essential fields have increased requirements for mag-nesium(Mg)alloys with good room-temperature and high-temperature mechanical properties.However,the high-temperature mechanic-al properties of commonly used commercial Mg alloys,such as AZ91D,deteriorate considerably with increasing temperatures.Over the past several decades,extensive efforts have been devoted to developing heat-resistant Mg alloys.These approaches either inhibit the gen-eration of thermally unstable phases or promote the formation of thermally stable precipitates/phases in matrices through solid solution or precipitation strengthening.In this review,numerous studies are systematically introduced and discussed.Different alloy systems,includ-ing those based on Mg–Al,Mg–Zn,and Mg–rare earth,are carefully classified and compared to reveal their mechanical properties and strengthening mechanisms.The emphasis,limitations,and future prospects of these heat-resistant Mg alloys are also pointed out and dis-cussed to develop heat-resistant Mg alloys and broaden their potential application areas in the future.展开更多
Magnesium and magnesium alloy foils have great potential for application in battery anodes,electromagnetic shielding,optics and acoustics,and biology because of their excellent specific damping,internal dissipation co...Magnesium and magnesium alloy foils have great potential for application in battery anodes,electromagnetic shielding,optics and acoustics,and biology because of their excellent specific damping,internal dissipation coefficients,magnetic and electrical conductivities,as well as high theoretical specific capacity.However,magnesium alloys exhibit poor deformation ability due to their hexagonal close-packed crystal structure.Preparing magnesium and magnesium alloy foils with thicknesses of less than 0.1 mm is difficult because of surface oxidation and grain growth at high temperatures or severe anisotropy after cold rolling that leads to cracks.Numerous methods have been applied to prepare magnesium alloy foils.They include warm rolling,cold rolling,accumulative roll bonding,electric plastic rolling,and on-line heating rolling.Defects of magnesium and magnesium alloy foils during preparation,such as edge cracks and breakage,are important factors for consideration.Herein,the current status of the research on magnesium and magnesium alloy foils is summarized from the aspects of foil preparation,defect control,performance characterization,and application prospects.The advantages and disadvantages of different preparation methods and defect(edge cracks and breakage)mechanisms in the preparation of foils are identified.展开更多
In order to improve the bioavailability of lutein(LUT),a novel lutein-stevio side nanoparticle(LUT-STE)were prepared previously,but the information about LUT-STE on protecting of eye health was limited.This study inve...In order to improve the bioavailability of lutein(LUT),a novel lutein-stevio side nanoparticle(LUT-STE)were prepared previously,but the information about LUT-STE on protecting of eye health was limited.This study investigated the effect of LUT-STE on antioxidant activity of H_(2)O_(2)-induced human retinal pigment epithelial(ARPE)cells.LUT and LUT-STE(final concentration of 5μg/mL)significantly enhanced cell viability from(74.84±5.10)%to(81.92±10.01)%(LUT)and(89.33±4.34)%(LUT-STE),and inhibited the cell apoptosis(P<0.05).After pretreatment with LUT-STE in ARPE cells,the levels of superoxide dismutase(SOD),catalase(CAT)and glutathion peroxidase(GSH-Px)in ARPE cells were significantly increased(P<0.05),the contents of reactive oxygen species(ROS)and malondialdehyde(MDA)were decreased.In addition,the vascular endothelial growth factor(VEGF)levels were inhibited by 13.61%and 17.39%,respectively,pretreatment with LUT and LUT-STE.Western blotting results showed that the pretreatment with LUT-STE inhibited the expression of caspase-9 and caspase-3 and up-regulated Bcl-2/Bax pathway to inhibit H_(2)O_(2)-induced apoptosis.In summary,the novel delivery LUT-STE had more pronounced inhibitory effect on H_(2)O_(2)-induced damage in human ARPE cells.展开更多
Since the introduction of Tesla's Giga-Casting process, the automotive industry has widely accepted the concept of super-sized structural components due to their significant potential for enhancing the light-weigh...Since the introduction of Tesla's Giga-Casting process, the automotive industry has widely accepted the concept of super-sized structural components due to their significant potential for enhancing the light-weighting of both electric and internal combustion engine vehicles.These super-sized components can be further lightened by using Mg alloys because of their exceptional lightweight characteristics, with a density only two-thirds that of aluminium alloys and one-fourth that of steel. This outstanding attribute offers the attractive prospect of achieving significant weight reduction without compromising structural integrity. This review examines studies on the Mg-alloy HighPressure Die Casting(HPDC) process, providing insights into the future prospects of incorporating Mg alloys into super-sized automotive HPDC components.展开更多
Generally,edge crack of rolled magnesium alloy sheets initiates in the RD(rolling direction)-ND(normal direction)plane and then propagate in the RD-TD(transverse direction)plane.Hence,the Mg-2Zn-1.5Mn(ZM21)alloy sheet...Generally,edge crack of rolled magnesium alloy sheets initiates in the RD(rolling direction)-ND(normal direction)plane and then propagate in the RD-TD(transverse direction)plane.Hence,the Mg-2Zn-1.5Mn(ZM21)alloy sheets with and without crack notch were designed to carry out in-situ tensile experiments under 150℃(the same temperature of rolling),with the aim to understand their crack propagation mechanism.The scanning electron microscopy(SEM)and electron backscattered diffraction(EBSD)techniques were utilized to reveal microstructural evolution in real time at designated displacements.The results show that the prismatic slip,basal slip,and extension twining play synergistic role in coordinating strain during the tensile process in ZM21 alloy sheet at 150℃.In both tensile samples with and without crack notch,localized strain is mainly concentrated at relatively fine grain area and the grain boundaries or triple junctions of the grains with large basal Schmid factor(SF)difference,which eventually leads to severe surface roughening and subsequent crack initiation.Compared with the sample without crack notch,the pre-cracked sample exhibits severer deformation at the crack tip due to strain concentration.Strain gradient distribution is observed at the crack tip region in the pre-cracked sample.The crack propagation path of the sample with pre-crack is identified and the underlying mechanism is also discussed.展开更多
Magnesium and its alloys have such advantages with lightweight, high specific strength, good damping, high castability and machinability,which make them an attractive choice for applications where weight reduction is ...Magnesium and its alloys have such advantages with lightweight, high specific strength, good damping, high castability and machinability,which make them an attractive choice for applications where weight reduction is important, such as in the aerospace and automotive industries.However, their practical applications are still limited because of their poor corrosion resistance, low high temperature strength and ambient formability. Based on such their property shortcomings, recently degradable magnesium alloys were developed for broadening their potential applications. Considering the degradable Mg alloys for medical applications were well reviewed, the present review put an emphasis on such degradable magnesium alloys for structural and functional applications, especially the applications in the environmental and energy fields. Their applications as fracture ball in fossil energy, sacrificial anode, washing ball, and as battery anodes, transient electronics, were summarized. The roles of alloying elements in magnesium and the design concept of such degradable magnesium alloys were discussed. The existing challenges for extending their future applications are explored.展开更多
In order to effectively deliver lutein to the inflamed colon and better exert its pharmacological activity,this paper constructed a sodium alginate hydrogel-based delivery system loaded with lutein nanoparticles,evalu...In order to effectively deliver lutein to the inflamed colon and better exert its pharmacological activity,this paper constructed a sodium alginate hydrogel-based delivery system loaded with lutein nanoparticles,evaluated the regulation on the expression and secretion of related inflammatory factors in mice with colitis,and its impact on intestinal microbial environment.The results showed that comparing lutein crystal and its nanoparticle,lutein hydrogel alleviated dextran sodium sulfate(DSS)-induced colitis in mice more effectively by adjusting fecal heme content,colon tissue damage,and inflammatory factor levels.Moreover,lutein hydrogel increased the expression of intestinal tight junction proteins zonula occluden-1(ZO-1),claudin-1 and occludin to maintain the integrity of the intestinal-barrier,inhibited the nuclear factor-κB(NF-κB)pathway and reduced expression and secretion of inflammatory factors including tumour necrosis factor-α(TNF-α),inducible nitric oxide synthase(iNOS),NOD-like receptors 3(NLRP3)and interleukin(IL)-1β.In addition,the intestinal microbial environment of mice with colitis was improved by down-regulating the relative abundance of Desulfovibrionaceae and up-regulating the relative abundance of Erysipelotrichaceae and Rikenellaceae.As a slow-release carrier to load lutein nanoparticles,sodium alginate-based hydrogel has potential application prospect.展开更多
In the past two years,significant progresses have been achieved in high-performance cast and wrought magnesium and magnesium alloys,magnesium-based composites,advanced cast technologies,advanced processing technologie...In the past two years,significant progresses have been achieved in high-performance cast and wrought magnesium and magnesium alloys,magnesium-based composites,advanced cast technologies,advanced processing technologies,and functional magnesium materials,such as Mg ion batteries,hydrogen storage Mg materials,bio-magnesium alloys,etc.Great contributions to the development of new magnesium alloys and their processing technologies have been made by Chongqing University,Shanghai Jiaotong University,Chinese Academy of Sciences,Helmholtz Zentrum Geesthacht,Queensland University,Brunel University,etc.This review paper is aimed to summarize the latest important advances in cast magnesium alloys,wrought magnesium alloys and functional magnesium materials worldwide in 2018–2019,including both the development of new materials and the innovation of their processing technologies.Based on the issues and challenges identified here,some future research directions are suggested,including further development of high-performance magnesium alloys having high strength and superior plasticity together with high corrosion resistance and low cost,and fundamental research on the phase diagram,diffusion,precipitation,etc.,as well as the development of advanced welding and joining technology.展开更多
More than 4000 papers in the field of Mg and Mg alloys were published and indexed in Web of Science(WoS)Core Collection database in 2021.The bibliometric analyses indicate that the microstructure,mechanical properties...More than 4000 papers in the field of Mg and Mg alloys were published and indexed in Web of Science(WoS)Core Collection database in 2021.The bibliometric analyses indicate that the microstructure,mechanical properties,and corrosion of Mg alloys still are the main research focus.Mg ion batteries and hydrogen storage Mg materials have attracted much attention.Significant contributions to the research and development of magnesium alloys were made by Chongqing University,Shanghai Jiaotong University,and Chinese Academy of Sciences in China,Helmholtz Zentrum Hereon in Germany,Ohio State University in the United States,the University of Queensland in Australia,Kumanto University in Japan,and Seoul National University in Korea,University of Tehran in Iran,etc..This review is aimed to summarize the progress in the development of structural and functional Mg and Mg alloys in 2021.Based on the issues and challenges identified here,some future research directions are suggested.展开更多
The mechanical properties and microstructure were investigated under different Zn content and heat treatment conditions in a Mg-Zn-YGd cast alloy.A part of the long period stacking order(LPSO)phases transformed to W-M...The mechanical properties and microstructure were investigated under different Zn content and heat treatment conditions in a Mg-Zn-YGd cast alloy.A part of the long period stacking order(LPSO)phases transformed to W-M^ZnaRE?phases with an increase in Zn content from 0.9 at.%to 1.8 at.%,and the ultimate tensile strength(UTS)increased from 229 MPa to 248 MPa.With solution treatment at 480°C,the content of the LPSO phase and strength sharply decreased in the Mg-1.8Zn-0.8Y-0.8Gd alloy,whereas this change was not significantly observed in the Mg-0.9Zn-O.8Y-O.8Gd alloy.After solution treatment,the elongation significantly improved and the UTS sharply decreased in both alloys.The lamellar and filminess LPSO phases were observed with aging treatment at 200℃.Moreover,the strengthening efficiency of lamellar and filminess LPSO phases was lower than that of the block LPSO phases.Therefore,the UTS of the T6 state was lower than that of the as-cast alloy.展开更多
Hot tearing is often a major casting defect in magnesium alloys and has a significant impact on the quality of their casting products.Hot tearing of magnesium alloys is a complex solidification phenomenon which is sti...Hot tearing is often a major casting defect in magnesium alloys and has a significant impact on the quality of their casting products.Hot tearing of magnesium alloys is a complex solidification phenomenon which is still not fully understood,it is of great importance to investigate the hot tearing behaviour of magnesium alloys.This review attempts to summarize the investigations on hot tearing of magnesium alloys over the past decades.The hot tearing criteria including recently developed Kou’s criterion are summarized and compared.The numeric simulation and assessing methods of hot tearing,factors influencing hot tearing,and hot tearing susceptibility(HTS)of magnesium alloys are discussed.展开更多
Currently, many gratifying signs of progress have been made in magnesium(Mg) matrix composites(MMCs) by virtue of their high mechanical properties both at room and elevated temperatures. Although the commonly used rei...Currently, many gratifying signs of progress have been made in magnesium(Mg) matrix composites(MMCs) by virtue of their high mechanical properties both at room and elevated temperatures. Although the commonly used reinforcements in MMCs are ceramic particles,they often provide improved yield and ultimate stresses by a significant loss in ductility. Therefore, hard metallic phases were introduced as alternative candidates for the manufacturing of MMCs, especially titanium(Ti). It has a high melting point, high Young’s modulus, high plasticity, low level of mutual solubility with Mg matrix, and closer thermal expansion coefficient to that of Mg metal than that of ceramic particles. It is highly preferable to provide both high ultimate stress and ductility in Mg matrix. However, many critical challenges for the fabrication of Ti-reinforced MMCs remain, such as Ti’s homogeneity, low recovery rate, and the optimization of interfacial bonding strength between Mg and Ti, etc. Meanwhile, different fabrication methods have various effects on the microstructures, mechanical properties, and the interfacial strength of Ti-reinforced MMCs. Hence, this review placed emphasis on the microstructural characteristics and mechanical properties of Ti-reinforced MMCs fabricated by different techniques. The influencing factors that govern the strengthening mechanisms were systematically compared and discussed. Future research trends, key issues, and prospects were also proposed to develop Ti-reinforced MMCs.展开更多
The mechanical properties of as-extruded AZ80 magnesium alloy at temperatures of 450-525℃ and strain rates of 3.0 s^(−1)and 0.15 s^(−1)were investigated by tensile tests.Zero ductility of alloy appeared at 500℃ with...The mechanical properties of as-extruded AZ80 magnesium alloy at temperatures of 450-525℃ and strain rates of 3.0 s^(−1)and 0.15 s^(−1)were investigated by tensile tests.Zero ductility of alloy appeared at 500℃ with a strain rate of 0.15 s^(−1),while the zero strength and zero ductility of the alloy were obtained nearly simultaneously at 525℃ with a strain rate of 3.0 s^(−1).The results indicated that the lower strain rate accelerated the arrival of zero ductility.As the temperature increased,the failure mode of the alloy developed from trans-granular fracture to cleavage fracture and then to inter-granular fracture with the feature of sugar-like grains and fusion traces.The existence of the low-melting composite ofβ-Mg_(17)Al_(12) and Al_(8)Mn_(5) particles segregated near the Mg_(17)Al_(12) phase along grain boundaries were demonstrated to be the reason for the brittle fracturing of the AZ80 alloy at high temperatures.Furthermore,microstructural evolution at temperatures approaching the solidus temperature was discussed to clarify magnesium alloy’s high temperature deformation mechanism.展开更多
The liquid phase catalytic exchange(LPCE) reaction is an effective process for heavy water detritiation and production of deuterium-depleted potable water. In the current study, hydrophobic carbon-supported platinum c...The liquid phase catalytic exchange(LPCE) reaction is an effective process for heavy water detritiation and production of deuterium-depleted potable water. In the current study, hydrophobic carbon-supported platinum catalysts(Pt/C/PTFE) with high efficiency as reported previously for LPCE were prepared and comprehensive performance evaluation method is applied to evaluate the separation behaviors of LPCE systematically. Experimental results indicate that the optimum reaction temperature of 60–80℃ and the molar feed ratio G/L of 1.5–2.5 would lead to higher separation efficiencies. As to the packing method, a random packing mode with a packing ratio of hydrophobic catalysts 0.25 is recommended. In addition, thermodynamic analysis corresponds well with experimental results under lower temperature and G/L, while the suppression of kinetic factors should not be neglected when T > 80℃ and G/L > 1.5.展开更多
The present work devotes to studying the electric properties: electric quadrupole moment and electric field gradient (EFG) of molecules PdH and (PdH)-2 based on the full relativistic theory. It is the first time to ex...The present work devotes to studying the electric properties: electric quadrupole moment and electric field gradient (EFG) of molecules PdH and (PdH)-2 based on the full relativistic theory. It is the first time to explore that the force constants are essentially caused by electric field gradients, and indirectly with spectroscopic data. If EFG is positive, zero or negative, then the will be positive, zero or negative. Therefore, second order force constants are adjustable to changing the intensity of EFG.展开更多
The corrosion behavior at open circuit potential(OCP)and discharge properties under applied anodic currents of twoα-Mg based Mg-Li alloys,i.e.,LAZ131 and LAZ531,with different microstructural features for primary Mg-...The corrosion behavior at open circuit potential(OCP)and discharge properties under applied anodic currents of twoα-Mg based Mg-Li alloys,i.e.,LAZ131 and LAZ531,with different microstructural features for primary Mg-air batteries are investigated.The results show that the grain boundaries contribute equally to the corrosion and discharge processes,which are attacked preferentially than the grain interiors and accelerate the dissolution processes ofα-Mg based Mg-Li alloys.The(10-10)/(11-20)orientated grains are attacked preferentially than the(0002)orientated grains on the corrosion and discharge process.The increased corrosion rate and improved discharge properties are attributed to the refinement of grain size,decreased content of(0002)orientated grains and increased content of(10-10)/(11-20)orientated grains.Of those,the LAZ531 alloy possesses high and steady discharge voltage at small discharge current density for long time,with the values of 1.4801 V at 2.5 mA cm^(-2)and 1.3742 V at 10 mA cm^(-2).展开更多
Highly oriented Mg-Al layered double hydroxide(LDHs)films were deposited on magnesium alloy AZ31 with different deformation processes by an easy in-situ growth method.The characteristics of the films were investigated...Highly oriented Mg-Al layered double hydroxide(LDHs)films were deposited on magnesium alloy AZ31 with different deformation processes by an easy in-situ growth method.The characteristics of the films were investigated by optical microscopy(OM),X-ray diffraction(XRD),scanning electron microscopy(SEM),and electrochemical,immersion and hydrogen evolution tests.The corrosion protection performance ranked the LDHs films as the increasing series:CS-LDHs(as-cast sample with LDHs)<AE-LDHs(asymmetric extrusion sample with LDHs)<SE-LDHs(symmetric extrusion sample with LDHs)<RS-LDHs(rolled sample with LDHs).A thicker and more compact LDH conversion coating was formed on the RS sample,and had the best corrosion protection performance.展开更多
Triboelectric nanogenerator(TENG)can directly convert mechanical energy into electric energy.However,the triboelectric materials are limited to the triboelectric series.Here,for the first time,we choose the isostructu...Triboelectric nanogenerator(TENG)can directly convert mechanical energy into electric energy.However,the triboelectric materials are limited to the triboelectric series.Here,for the first time,we choose the isostructural UiO-66-X(X=H,NH_(2),NO_(2),and Br)family as triboelectric materials to investigate the underlying relationships between different functional groups and the triboelectric performance of TENG.Unlike traditional triboelectric material organic polymers,metal–organic frameworks(MOFs)can be oriented design synthesis and functionalized with various functional groups.The results demonstrate that the largest output voltage and current are from UiO-66-NO_(2) TENG,and are about 23.79 V and 0.29μA,which are 3.19 and 4.14 times over that of the UiO-66 TENG,respectively.The working mechanism of the MOF TENG was discussed in depth through experiments and theoretical calculations.This work proves a novel strategy to obtain high output properties by functionalized MOFs with large electron-withdrawing functional groups and promising guidance for the choice of high-efficiency triboelectric materials.展开更多
On-line heating rolling mill which could efficiently preheat sheet and apply tensile force on both ends of the sheet along rolling direction(RD)was used to investigate the effect of tension on mechanical behavior and ...On-line heating rolling mill which could efficiently preheat sheet and apply tensile force on both ends of the sheet along rolling direction(RD)was used to investigate the effect of tension on mechanical behavior and shape quality of magnesium sheets.For revealing the infl uence mechanism,many analysis techniques including optical microscope,electron backscattered diffraction,macrotexture and transmission electron microscope were performed.The shape defect,edge wave,could be eliminated under higher tension along RD,which was attributed to more uniform distribution of microstructure and microstrain.Nevertheless,it is undesirable that the forward tensile force exceeds 3 kN in present work because the strength decreased for high recrystallization level when the tensile force is beyond this value.Furthermore,the main deformation mode was still slip during rolling process despite of accompanying twining,e.g.,double twins,but more prismatic slip activated when tensile force exceeds 3 kN.The distribution of shear bands was affected by the applied tensile force that they appear as"V"shape along RD at a low forward or backward tensile force,while they appear as reticulate shape under applied tensile force of 5 kN.展开更多
基金supported by the National Key Research and Development Program of China(No.2022YFB3709300)the National Natural Science Foundation of China(Nos.52101123,U1764253,51971044,U1910213,52001037,U21A2048,U207601,and 52101126)+1 种基金the Natural Science Foundation of Chongqing,China(No.CSTB2023NSCQ-MSX0571)the Qinghai Scientific&Technological Program,China(No.2018-GX-A1).
文摘With the increasing attention received by lightweight metals,numerous essential fields have increased requirements for mag-nesium(Mg)alloys with good room-temperature and high-temperature mechanical properties.However,the high-temperature mechanic-al properties of commonly used commercial Mg alloys,such as AZ91D,deteriorate considerably with increasing temperatures.Over the past several decades,extensive efforts have been devoted to developing heat-resistant Mg alloys.These approaches either inhibit the gen-eration of thermally unstable phases or promote the formation of thermally stable precipitates/phases in matrices through solid solution or precipitation strengthening.In this review,numerous studies are systematically introduced and discussed.Different alloy systems,includ-ing those based on Mg–Al,Mg–Zn,and Mg–rare earth,are carefully classified and compared to reveal their mechanical properties and strengthening mechanisms.The emphasis,limitations,and future prospects of these heat-resistant Mg alloys are also pointed out and dis-cussed to develop heat-resistant Mg alloys and broaden their potential application areas in the future.
基金financially supported by the National Key Research and Development Program of China(Nos.2022 YFB3709300 and 2021YFB3701000)the National Natural Science Foundation of China(Nos.52271090 and 52071036)+1 种基金the Guangdong Major Project of Basic and Applied Basic Research(No.2020B0301030006)the Independent Research Project of State Key Laboratory of Mechanical Transmissions(Nos.SKLMT-ZZKT-2022Z01 and S KLMT-ZZKT-2022M12)。
文摘Magnesium and magnesium alloy foils have great potential for application in battery anodes,electromagnetic shielding,optics and acoustics,and biology because of their excellent specific damping,internal dissipation coefficients,magnetic and electrical conductivities,as well as high theoretical specific capacity.However,magnesium alloys exhibit poor deformation ability due to their hexagonal close-packed crystal structure.Preparing magnesium and magnesium alloy foils with thicknesses of less than 0.1 mm is difficult because of surface oxidation and grain growth at high temperatures or severe anisotropy after cold rolling that leads to cracks.Numerous methods have been applied to prepare magnesium alloy foils.They include warm rolling,cold rolling,accumulative roll bonding,electric plastic rolling,and on-line heating rolling.Defects of magnesium and magnesium alloy foils during preparation,such as edge cracks and breakage,are important factors for consideration.Herein,the current status of the research on magnesium and magnesium alloy foils is summarized from the aspects of foil preparation,defect control,performance characterization,and application prospects.The advantages and disadvantages of different preparation methods and defect(edge cracks and breakage)mechanisms in the preparation of foils are identified.
基金the National Natural Science Foundation of China (31801541)the Independent Innovation Fund Project of Agricultural Science and Technology in Jiangsu Province (CX (22)3065)+1 种基金Major Scientific and Technological Achievements Transformation Project of Taizhou (SCG 202105)the Taizhou Science and Technology Support Plan (TN202106)。
文摘In order to improve the bioavailability of lutein(LUT),a novel lutein-stevio side nanoparticle(LUT-STE)were prepared previously,but the information about LUT-STE on protecting of eye health was limited.This study investigated the effect of LUT-STE on antioxidant activity of H_(2)O_(2)-induced human retinal pigment epithelial(ARPE)cells.LUT and LUT-STE(final concentration of 5μg/mL)significantly enhanced cell viability from(74.84±5.10)%to(81.92±10.01)%(LUT)and(89.33±4.34)%(LUT-STE),and inhibited the cell apoptosis(P<0.05).After pretreatment with LUT-STE in ARPE cells,the levels of superoxide dismutase(SOD),catalase(CAT)and glutathion peroxidase(GSH-Px)in ARPE cells were significantly increased(P<0.05),the contents of reactive oxygen species(ROS)and malondialdehyde(MDA)were decreased.In addition,the vascular endothelial growth factor(VEGF)levels were inhibited by 13.61%and 17.39%,respectively,pretreatment with LUT and LUT-STE.Western blotting results showed that the pretreatment with LUT-STE inhibited the expression of caspase-9 and caspase-3 and up-regulated Bcl-2/Bax pathway to inhibit H_(2)O_(2)-induced apoptosis.In summary,the novel delivery LUT-STE had more pronounced inhibitory effect on H_(2)O_(2)-induced damage in human ARPE cells.
基金the funding from the National Key R&D Program of China (No.2022YFB3709300 and No.2021YFB3701000)National Natural Science Foundation of China (No.U21A2048,No.52271090,and No.52101125)。
文摘Since the introduction of Tesla's Giga-Casting process, the automotive industry has widely accepted the concept of super-sized structural components due to their significant potential for enhancing the light-weighting of both electric and internal combustion engine vehicles.These super-sized components can be further lightened by using Mg alloys because of their exceptional lightweight characteristics, with a density only two-thirds that of aluminium alloys and one-fourth that of steel. This outstanding attribute offers the attractive prospect of achieving significant weight reduction without compromising structural integrity. This review examines studies on the Mg-alloy HighPressure Die Casting(HPDC) process, providing insights into the future prospects of incorporating Mg alloys into super-sized automotive HPDC components.
基金This work was financially supported by the National Key Research and development Program(2021YFB3701000)National Science Foundation of China(No.52071036,U2037601)+1 种基金the Guangdong Major Project of Basic and Applied Basic Research(2020B0301030006)the Independent Research Project of State Key Laboratory of Mechanical Transmissions(SKLMT-ZZKT-2022Z01,SKLMT-ZZKT-2022M12).
文摘Generally,edge crack of rolled magnesium alloy sheets initiates in the RD(rolling direction)-ND(normal direction)plane and then propagate in the RD-TD(transverse direction)plane.Hence,the Mg-2Zn-1.5Mn(ZM21)alloy sheets with and without crack notch were designed to carry out in-situ tensile experiments under 150℃(the same temperature of rolling),with the aim to understand their crack propagation mechanism.The scanning electron microscopy(SEM)and electron backscattered diffraction(EBSD)techniques were utilized to reveal microstructural evolution in real time at designated displacements.The results show that the prismatic slip,basal slip,and extension twining play synergistic role in coordinating strain during the tensile process in ZM21 alloy sheet at 150℃.In both tensile samples with and without crack notch,localized strain is mainly concentrated at relatively fine grain area and the grain boundaries or triple junctions of the grains with large basal Schmid factor(SF)difference,which eventually leads to severe surface roughening and subsequent crack initiation.Compared with the sample without crack notch,the pre-cracked sample exhibits severer deformation at the crack tip due to strain concentration.Strain gradient distribution is observed at the crack tip region in the pre-cracked sample.The crack propagation path of the sample with pre-crack is identified and the underlying mechanism is also discussed.
文摘Magnesium and its alloys have such advantages with lightweight, high specific strength, good damping, high castability and machinability,which make them an attractive choice for applications where weight reduction is important, such as in the aerospace and automotive industries.However, their practical applications are still limited because of their poor corrosion resistance, low high temperature strength and ambient formability. Based on such their property shortcomings, recently degradable magnesium alloys were developed for broadening their potential applications. Considering the degradable Mg alloys for medical applications were well reviewed, the present review put an emphasis on such degradable magnesium alloys for structural and functional applications, especially the applications in the environmental and energy fields. Their applications as fracture ball in fossil energy, sacrificial anode, washing ball, and as battery anodes, transient electronics, were summarized. The roles of alloying elements in magnesium and the design concept of such degradable magnesium alloys were discussed. The existing challenges for extending their future applications are explored.
基金supported by the Independent Innovation Fund Project of Agricultural Science and Technology in Jiangsu Province(Project No.CX(20)3047).
文摘In order to effectively deliver lutein to the inflamed colon and better exert its pharmacological activity,this paper constructed a sodium alginate hydrogel-based delivery system loaded with lutein nanoparticles,evaluated the regulation on the expression and secretion of related inflammatory factors in mice with colitis,and its impact on intestinal microbial environment.The results showed that comparing lutein crystal and its nanoparticle,lutein hydrogel alleviated dextran sodium sulfate(DSS)-induced colitis in mice more effectively by adjusting fecal heme content,colon tissue damage,and inflammatory factor levels.Moreover,lutein hydrogel increased the expression of intestinal tight junction proteins zonula occluden-1(ZO-1),claudin-1 and occludin to maintain the integrity of the intestinal-barrier,inhibited the nuclear factor-κB(NF-κB)pathway and reduced expression and secretion of inflammatory factors including tumour necrosis factor-α(TNF-α),inducible nitric oxide synthase(iNOS),NOD-like receptors 3(NLRP3)and interleukin(IL)-1β.In addition,the intestinal microbial environment of mice with colitis was improved by down-regulating the relative abundance of Desulfovibrionaceae and up-regulating the relative abundance of Erysipelotrichaceae and Rikenellaceae.As a slow-release carrier to load lutein nanoparticles,sodium alginate-based hydrogel has potential application prospect.
基金The content in this review is financially supported by the National Key Research and Development Program of China(No.2016YFB0301100,2017YFF0209100)the National Science Foundation for Scientists of China(No.51531002,51474043,51701027,51971042,51901028)the Chongqing Academician Special Fund(cstc2018jcyj-yszxX0007,cstc2019yszxjcyjX0004).
文摘In the past two years,significant progresses have been achieved in high-performance cast and wrought magnesium and magnesium alloys,magnesium-based composites,advanced cast technologies,advanced processing technologies,and functional magnesium materials,such as Mg ion batteries,hydrogen storage Mg materials,bio-magnesium alloys,etc.Great contributions to the development of new magnesium alloys and their processing technologies have been made by Chongqing University,Shanghai Jiaotong University,Chinese Academy of Sciences,Helmholtz Zentrum Geesthacht,Queensland University,Brunel University,etc.This review paper is aimed to summarize the latest important advances in cast magnesium alloys,wrought magnesium alloys and functional magnesium materials worldwide in 2018–2019,including both the development of new materials and the innovation of their processing technologies.Based on the issues and challenges identified here,some future research directions are suggested,including further development of high-performance magnesium alloys having high strength and superior plasticity together with high corrosion resistance and low cost,and fundamental research on the phase diagram,diffusion,precipitation,etc.,as well as the development of advanced welding and joining technology.
基金support from the Guangdong Major Project of Basic and Applied Basic Research(2020B0301030006)National Natural Science Foundation of China(NSFC)(No.52071036)+1 种基金Key Research and Development Program of Zhejiang Province(No.2021C01086)the Fundamental Research Funds for the Central Universities Project(Nos.2021CDJCGJ009,SKLMT-ZZKT-2021M11)is also gratefully acknowledged.
文摘More than 4000 papers in the field of Mg and Mg alloys were published and indexed in Web of Science(WoS)Core Collection database in 2021.The bibliometric analyses indicate that the microstructure,mechanical properties,and corrosion of Mg alloys still are the main research focus.Mg ion batteries and hydrogen storage Mg materials have attracted much attention.Significant contributions to the research and development of magnesium alloys were made by Chongqing University,Shanghai Jiaotong University,and Chinese Academy of Sciences in China,Helmholtz Zentrum Hereon in Germany,Ohio State University in the United States,the University of Queensland in Australia,Kumanto University in Japan,and Seoul National University in Korea,University of Tehran in Iran,etc..This review is aimed to summarize the progress in the development of structural and functional Mg and Mg alloys in 2021.Based on the issues and challenges identified here,some future research directions are suggested.
基金The authors would like to acknowledge financial support by the National Natural Science Foundation(Project No.51701026)the Chongqing Research Program of Basic Research and Frontier Technology(Project No.cstc2018jcyjAX0611)+2 种基金the Science and Technology Research Program of Chongqing Municipal Education Commission(Grant No.KJQN201803103)the Fundamental Research Funds for the Central Universities(Project No.2018CDGFCL0005 and Project No.2018CDJDCL0019)the support of the 111 Project(Project No.B 16007)by the Ministry of Education and the State Administration of Foreign Experts Affairs of China.
文摘The mechanical properties and microstructure were investigated under different Zn content and heat treatment conditions in a Mg-Zn-YGd cast alloy.A part of the long period stacking order(LPSO)phases transformed to W-M^ZnaRE?phases with an increase in Zn content from 0.9 at.%to 1.8 at.%,and the ultimate tensile strength(UTS)increased from 229 MPa to 248 MPa.With solution treatment at 480°C,the content of the LPSO phase and strength sharply decreased in the Mg-1.8Zn-0.8Y-0.8Gd alloy,whereas this change was not significantly observed in the Mg-0.9Zn-O.8Y-O.8Gd alloy.After solution treatment,the elongation significantly improved and the UTS sharply decreased in both alloys.The lamellar and filminess LPSO phases were observed with aging treatment at 200℃.Moreover,the strengthening efficiency of lamellar and filminess LPSO phases was lower than that of the block LPSO phases.Therefore,the UTS of the T6 state was lower than that of the as-cast alloy.
基金the National Natural Science Foundation of China(Project 51531002,51474043)the Ministry of Science&Technology of China(2013DFA71070)+1 种基金the Ministry of Education of China(SRFDR 20130191110018)Chongqing Municipal Government(CSTC2013JCYJC60001,CEC project,Two River Scholar Project and The Chief Scientist Studio Project).
文摘Hot tearing is often a major casting defect in magnesium alloys and has a significant impact on the quality of their casting products.Hot tearing of magnesium alloys is a complex solidification phenomenon which is still not fully understood,it is of great importance to investigate the hot tearing behaviour of magnesium alloys.This review attempts to summarize the investigations on hot tearing of magnesium alloys over the past decades.The hot tearing criteria including recently developed Kou’s criterion are summarized and compared.The numeric simulation and assessing methods of hot tearing,factors influencing hot tearing,and hot tearing susceptibility(HTS)of magnesium alloys are discussed.
基金National Natural Science Foundation of China (52101123, 52171103)Guangdong Major Project of Basic and Applied Basic Research (2020B0301030006) for the support。
文摘Currently, many gratifying signs of progress have been made in magnesium(Mg) matrix composites(MMCs) by virtue of their high mechanical properties both at room and elevated temperatures. Although the commonly used reinforcements in MMCs are ceramic particles,they often provide improved yield and ultimate stresses by a significant loss in ductility. Therefore, hard metallic phases were introduced as alternative candidates for the manufacturing of MMCs, especially titanium(Ti). It has a high melting point, high Young’s modulus, high plasticity, low level of mutual solubility with Mg matrix, and closer thermal expansion coefficient to that of Mg metal than that of ceramic particles. It is highly preferable to provide both high ultimate stress and ductility in Mg matrix. However, many critical challenges for the fabrication of Ti-reinforced MMCs remain, such as Ti’s homogeneity, low recovery rate, and the optimization of interfacial bonding strength between Mg and Ti, etc. Meanwhile, different fabrication methods have various effects on the microstructures, mechanical properties, and the interfacial strength of Ti-reinforced MMCs. Hence, this review placed emphasis on the microstructural characteristics and mechanical properties of Ti-reinforced MMCs fabricated by different techniques. The influencing factors that govern the strengthening mechanisms were systematically compared and discussed. Future research trends, key issues, and prospects were also proposed to develop Ti-reinforced MMCs.
基金financially supported by the National Natural Science Foundation of China (Nos. U1910213, 52001037, and U207601)the Chongqing Science and Technology Commission, China (Nos. cstc2020jcyj-msxmX0184 and cstc2019jscx-mbdx X0031)+2 种基金the University Innovation Research Group of Chongqing, China (No. CXQT20023)the Qinghai Scientific and Technological Plan Projects, China (No. 2018-GX-A1)the Scientific Research Foundation of Chongqing University of Technology, China
文摘The mechanical properties of as-extruded AZ80 magnesium alloy at temperatures of 450-525℃ and strain rates of 3.0 s^(−1)and 0.15 s^(−1)were investigated by tensile tests.Zero ductility of alloy appeared at 500℃ with a strain rate of 0.15 s^(−1),while the zero strength and zero ductility of the alloy were obtained nearly simultaneously at 525℃ with a strain rate of 3.0 s^(−1).The results indicated that the lower strain rate accelerated the arrival of zero ductility.As the temperature increased,the failure mode of the alloy developed from trans-granular fracture to cleavage fracture and then to inter-granular fracture with the feature of sugar-like grains and fusion traces.The existence of the low-melting composite ofβ-Mg_(17)Al_(12) and Al_(8)Mn_(5) particles segregated near the Mg_(17)Al_(12) phase along grain boundaries were demonstrated to be the reason for the brittle fracturing of the AZ80 alloy at high temperatures.Furthermore,microstructural evolution at temperatures approaching the solidus temperature was discussed to clarify magnesium alloy’s high temperature deformation mechanism.
基金Supported by the National Key Research and Development Program of China(2017YFE0300302)the National Natural Science Foundation of China(21503199,21406212)Key Project of Applied&Basic Research of Sichuan Province(18YYJC1594)
文摘The liquid phase catalytic exchange(LPCE) reaction is an effective process for heavy water detritiation and production of deuterium-depleted potable water. In the current study, hydrophobic carbon-supported platinum catalysts(Pt/C/PTFE) with high efficiency as reported previously for LPCE were prepared and comprehensive performance evaluation method is applied to evaluate the separation behaviors of LPCE systematically. Experimental results indicate that the optimum reaction temperature of 60–80℃ and the molar feed ratio G/L of 1.5–2.5 would lead to higher separation efficiencies. As to the packing method, a random packing mode with a packing ratio of hydrophobic catalysts 0.25 is recommended. In addition, thermodynamic analysis corresponds well with experimental results under lower temperature and G/L, while the suppression of kinetic factors should not be neglected when T > 80℃ and G/L > 1.5.
文摘The present work devotes to studying the electric properties: electric quadrupole moment and electric field gradient (EFG) of molecules PdH and (PdH)-2 based on the full relativistic theory. It is the first time to explore that the force constants are essentially caused by electric field gradients, and indirectly with spectroscopic data. If EFG is positive, zero or negative, then the will be positive, zero or negative. Therefore, second order force constants are adjustable to changing the intensity of EFG.
基金financially supported by the National Key Research and Development Program of China(Nos.2016YFB0101700 and 2016YFB0301104)the National Natural Science Foundation of China(Nos.51531002,U1764253,and 51971040)+2 种基金the Chongqing Science and Technology Commission(Nos.cstc2017zdcy-zdzx X0006 and cstc2019jscx-mbdxX0031)the Chongqing Scientific&Technological Talents Program(No.KJXX2017002)the Scientific Research Foundation of Chongqing University of Technology。
文摘The corrosion behavior at open circuit potential(OCP)and discharge properties under applied anodic currents of twoα-Mg based Mg-Li alloys,i.e.,LAZ131 and LAZ531,with different microstructural features for primary Mg-air batteries are investigated.The results show that the grain boundaries contribute equally to the corrosion and discharge processes,which are attacked preferentially than the grain interiors and accelerate the dissolution processes ofα-Mg based Mg-Li alloys.The(10-10)/(11-20)orientated grains are attacked preferentially than the(0002)orientated grains on the corrosion and discharge process.The increased corrosion rate and improved discharge properties are attributed to the refinement of grain size,decreased content of(0002)orientated grains and increased content of(10-10)/(11-20)orientated grains.Of those,the LAZ531 alloy possesses high and steady discharge voltage at small discharge current density for long time,with the values of 1.4801 V at 2.5 mA cm^(-2)and 1.3742 V at 10 mA cm^(-2).
基金financially supported by the National Natural Science Foundation of China(Nos.51971040,51701029 and 51531002)the National Key Research and Development Program of China(No.2016YFB0301100)+2 种基金the China Postdoctoral Science Foundation Funded Project(Nos.2017M620410 and 2018T110942)the Chongqing Postdoctoral Scientific Research Foundation(No.Xm2017010)the Fundamental Research Funds for the Central Universities(No.2018CDGFCL005)。
文摘Highly oriented Mg-Al layered double hydroxide(LDHs)films were deposited on magnesium alloy AZ31 with different deformation processes by an easy in-situ growth method.The characteristics of the films were investigated by optical microscopy(OM),X-ray diffraction(XRD),scanning electron microscopy(SEM),and electrochemical,immersion and hydrogen evolution tests.The corrosion protection performance ranked the LDHs films as the increasing series:CS-LDHs(as-cast sample with LDHs)<AE-LDHs(asymmetric extrusion sample with LDHs)<SE-LDHs(symmetric extrusion sample with LDHs)<RS-LDHs(rolled sample with LDHs).A thicker and more compact LDH conversion coating was formed on the RS sample,and had the best corrosion protection performance.
基金supported by National Natural Science Foundation of China(No.21905255)Natural Science Foundation of Shanxi Province(No.201901D211219).
文摘Triboelectric nanogenerator(TENG)can directly convert mechanical energy into electric energy.However,the triboelectric materials are limited to the triboelectric series.Here,for the first time,we choose the isostructural UiO-66-X(X=H,NH_(2),NO_(2),and Br)family as triboelectric materials to investigate the underlying relationships between different functional groups and the triboelectric performance of TENG.Unlike traditional triboelectric material organic polymers,metal–organic frameworks(MOFs)can be oriented design synthesis and functionalized with various functional groups.The results demonstrate that the largest output voltage and current are from UiO-66-NO_(2) TENG,and are about 23.79 V and 0.29μA,which are 3.19 and 4.14 times over that of the UiO-66 TENG,respectively.The working mechanism of the MOF TENG was discussed in depth through experiments and theoretical calculations.This work proves a novel strategy to obtain high output properties by functionalized MOFs with large electron-withdrawing functional groups and promising guidance for the choice of high-efficiency triboelectric materials.
基金financially supported by the National Science Foundation for Young Scientists of China(No.51701027)the National Key Research and Development Program of China(No.2017YFF0209100)+2 种基金the National Defense Basic Scientific Research Program of Chinathe Fundamental Research Funds for the Central Universities Project(No.2020CDJQY-A002)the Shanghai Rising—Star Program(No.18QB1401400)。
文摘On-line heating rolling mill which could efficiently preheat sheet and apply tensile force on both ends of the sheet along rolling direction(RD)was used to investigate the effect of tension on mechanical behavior and shape quality of magnesium sheets.For revealing the infl uence mechanism,many analysis techniques including optical microscope,electron backscattered diffraction,macrotexture and transmission electron microscope were performed.The shape defect,edge wave,could be eliminated under higher tension along RD,which was attributed to more uniform distribution of microstructure and microstrain.Nevertheless,it is undesirable that the forward tensile force exceeds 3 kN in present work because the strength decreased for high recrystallization level when the tensile force is beyond this value.Furthermore,the main deformation mode was still slip during rolling process despite of accompanying twining,e.g.,double twins,but more prismatic slip activated when tensile force exceeds 3 kN.The distribution of shear bands was affected by the applied tensile force that they appear as"V"shape along RD at a low forward or backward tensile force,while they appear as reticulate shape under applied tensile force of 5 kN.