Introducing B2 ordering can effectively improve the mechanical properties of lightweight refractory high-entropy alloys(LRHEAs).However,(Zr,Al)-enriched B2 precipitates generally reduce the ductility because their ord...Introducing B2 ordering can effectively improve the mechanical properties of lightweight refractory high-entropy alloys(LRHEAs).However,(Zr,Al)-enriched B2 precipitates generally reduce the ductility because their ordering characteristic is destroyed after dislocation shearing.Meanwhile,the local chemical order(LCO)cannot provide an adequate strengthening effect due to its small size.展开更多
As a typical tungsten-based composite consisting of tungsten(W)particles and matrix phase,tungsten heavy alloys(WHAs)are extensively utilized in the military due to their exceptional strength and high density.However,...As a typical tungsten-based composite consisting of tungsten(W)particles and matrix phase,tungsten heavy alloys(WHAs)are extensively utilized in the military due to their exceptional strength and high density.However,the large grain size(>30μm)of powder metallurgy liquid phase sintered(LPS)WHAs and the low strength of the matrix phase limit the further improvement of the alloy.In this work,high-density ultrafine WHAs were fabricated by two-step low-temperature sintering,and the density of the alloy reached 17 g/cm^(3) with an average W particle size of 7.81μm.Additionally,the eutectic reaction be-tween Ni and Ta was controlled to generate dispersed nano-Ni_(3)Ta phases in situ in the matrix phase,fur-ther improving the strength of the alloy.Under the synergistic strengthening effect of fine-grain strength-ening,dispersion strengthening,and solid solution strengthening,the average ultimate tensile strength of the alloy reached 1190.39 MPa.At the same time,the alloy maintained good elongation with a total elon-gation of 20.8%due to the good co-grid interface orientation between the Ni_(3)Ta phase and the matrix phase.This study provides a new idea for developing high-strength WHAs and has a guiding significance for developing Ni-based alloys.展开更多
Refractory high/medium-entropy alloys(RH/MEAs)are known for their outstanding performance at el-evated temperatures;however,they usually exhibit poor room-temperature plasticity,which can be at-tributed to the non-uni...Refractory high/medium-entropy alloys(RH/MEAs)are known for their outstanding performance at el-evated temperatures;however,they usually exhibit poor room-temperature plasticity,which can be at-tributed to the non-uniform deformation that occurs at room temperature.Once cracks nucleate,they will rapidly propagate into vertical splitting cracks.Here,we introduce multiple phases including FCC and HCP phases into the NbMoTa RMEA via appropriate addition of carbon.The results show that multiple-phase synergy effectively suppresses non-uniform deformation,thereby delaying the onset of vertical splitting cracks.An optimal combination of compressive strength-plasticity is achieved by the(NbMoTa)_(92.5)C_(7.5) alloy.The significant improvement in room-temperature mechanical properties can be attributed to its hierarchical microstructure:in the mesoscale,the BCC matrix is divided by eutectic structures;while at the microscale,the BCC matrix is further refined by abundant lath-like FCC precipitates.The FCC precip-itates contain high-density stacking faults,acting as a dislocation source under compressive loading.The HCP phase in the eutectic microstructures,in turn,acts as a strong barrier to dislocation movement and simultaneously increases the dislocation storage capacity.These findings open a new route to tailor the microstructure and mechanical properties of RH/MEAs.展开更多
This paper examines the effect of Fe addition on the microstructure characterized by scanning electron microscopy/electron backscattered diffraction,neutron diffraction,and synchrotron X-ray tomography and the mechani...This paper examines the effect of Fe addition on the microstructure characterized by scanning electron microscopy/electron backscattered diffraction,neutron diffraction,and synchrotron X-ray tomography and the mechanical properties of Al-Mg-Mn-Fe-Cu alloys.The findings reveal that the microstructures of the alloys consisted of an Al matrix,Al_(6)(FeMn),and Al_(2)CuMg phase particles.The addition of Fe significantly increased the yield strength(YS),and ultimate tensile strength(UTS)of the alloys,while reducing elongation.The transformation of the 3D morphology of the Al_(6)(FeMn)phase from separated and fine particles with Chinese-script morphology to interconnected rod-like structure as Fe content increased from 0.1%to 0.8%.This strengthening effect was attributed to the slip lines being blocked at the vicinity of the inter-connected Fe-rich phase,leading to grain rotation and dislocation density increment around the Fe-rich phase,ultimately improving the strength of the alloys.However,the Fe-rich phases and Al_(2)CuMg phases were found to be prone to cracking under tensile stress,resulting in decreased elongation of the alloys.This study provides a potential application in the design and manufacturing of new non-heat-treatable Al alloys for the automotive industry.展开更多
To effectively regulate the grain boundary infiltration in CoCrFeMnNi high-entropy alloy(Cantor alloys,HEA)caused by the violent atomic interdiffusion,the higher configuration entropy on Cantor alloys surface was desi...To effectively regulate the grain boundary infiltration in CoCrFeMnNi high-entropy alloy(Cantor alloys,HEA)caused by the violent atomic interdiffusion,the higher configuration entropy on Cantor alloys surface was designed and realized via eutectic high-entropy(EHEA)transformation.Meanwhile,to effectively alleviate the residual stress caused by the notable difference in the thermal expansion coefficient(CTE)between Cantor alloys and Zr-3 alloys,a cladding layer was applied to the HEA surface using laser cladding technology of Nb,followed by brazing to Zr-3 alloys with Zr63.2Cu filler.The cladding layer’s microstructure comprised Nbss and FCC+(Co,Ni)_(2) Nb eutectic structure,resulting from an in-situ reaction between Cantor alloys and Nb.The Nbss and FCC demonstrated good plasticity,and the(Co,Ni)_(2) Nb Laves phase provided increased strength,endowing both good plastic deformation ability and strength of the cladding layer.Notably,the existence of EHEA in the laser cladding layer made the Cantor alloy entropy from 1.61 R to 1.77 R,greatly enhancing its thermal stability and suppressing the grave grain boundary infiltration.Joints produced via laser cladding with Nb-assisted brazing exhibited a complex microstructure(HEA/Nbss+FCC+(Co,Ni)_(2)Nb/(Zr,Nb)(Cr,Mn)_(2)+(Zr,Nb)ss/(Zr,Nb)_(2)(Cu,Ni,Co,Fe)+(Zr,Nb)(Cr,Mn)_(2)+(Zr,Nb)ss/Zr-3) and a significantly improved shear strength of 242.8 MPa at 1010℃ for 10 min,42.4%higher than that of directly brazed joints.This improvement was attributed to reduced grain boundary infiltration,alleviated residual stress due to CTE disparity,and eliminated micro-cracks in the brazing seam.This study presents an effective solution for reducing residual stresses and achieving reliable bonding between Cantor alloys and Zr-3 alloys,with potential applications in brazing CoCrFeNi-based HEA and Zr-3 due to the beneficial eutectic reaction between CoCrFeNi and Nb.展开更多
The microstructure evolution and strengthening mechanism of WE54 alloy with different hard-plate rolling(HPR)processes were systematically investigated.The results suggest that the mechanical properties of the as-roll...The microstructure evolution and strengthening mechanism of WE54 alloy with different hard-plate rolling(HPR)processes were systematically investigated.The results suggest that the mechanical properties of the as-rolled alloys are significantly enhanced compared to those of the as-cast alloy.When subjected to three rolling passes at 450℃ and 490℃,grain refinement occurs due to dynamic recrystallization.A mixed-grain structure is formed after a single pass rolling with a substantial reduction(65%)at 490℃.The dynamic recrystallization(DRX)mechanism of the alloy during the HPR includes continuous dynamic recrystallization(CDRX),discontinuous dynamic recrystallization(DDRX),and twin-induced recrystallization(TDRX).The WE54 alloy exhibits the highest strength after three passes of HPR at 450℃,with tensile strength and yield strength of 374 and 323 MPa,respectively.The significant improvement in the mechanical properties of the alloy is primarily attributed to fine-grain strengthening,solid solution strengthening,and dislocation strengthening.展开更多
The unique structure and formation mechanism of medium-entropy alloys(MEAs)generally result in bet-ter comprehensive properties than traditional alloys.However,the strength-ductility trade-offremains a bottleneck,whic...The unique structure and formation mechanism of medium-entropy alloys(MEAs)generally result in bet-ter comprehensive properties than traditional alloys.However,the strength-ductility trade-offremains a bottleneck,which limits their applications.In this study,we designed novel high-performance CrNiCu x MEAs with a heterophase composition by incorporating a Cu-rich phase,and they were fabricated using laser-directed energy deposition(LDED).The results show that synergistic strengthening from multiple phases significantly improved the mechanical properties of the alloys,resulting in a tensile strength of 675 MPa and a ductility of 34.4%,demonstrating an excellent combination of high tensile strength and ductility.The improved mechanical properties of the CrNiCu x medium-entropy alloys are primarily due to the heterophase interfacial strengthening mechanism.In the alloy,numerous semi-coherent and coher-ent interfaces formed between the Cr-rich phase,Cu-rich phase,and the matrix,creating extensive lattice distortions at the interfaces.An increase in the Cu-rich phase content promoted the interaction between phases,enhancing the strain energy of the alloy and the barrier strength of the interfaces.The calcu-latedτint values,ranging from approximately 5.92-6.69 GPa,are significantly higher than those found in traditional alloys,providing a benchmark for designing new high-performance medium-entropy alloys.展开更多
OBJECTIVE:To evaluate the 10-year therapeutic efficacy of Traditional Chinese Medicine(TCM)using the Strengthening Spleen and Draining Dampness therapy in the management of idiopathic membranous nephropathy(IMN).METHO...OBJECTIVE:To evaluate the 10-year therapeutic efficacy of Traditional Chinese Medicine(TCM)using the Strengthening Spleen and Draining Dampness therapy in the management of idiopathic membranous nephropathy(IMN).METHODS:A single-center,retrospective analysis was conducted on patients diagnosed with IMN who met predefined inclusion and exclusion criteria.Data were collected from the Department of Nephrology at Longhua Hospital,affiliated with Shanghai University of Traditional Chinese Medicine,between January 2007 and December 2011.Clinical parameters including 24-h urinary protein,serum albumin,serum creatinine,and estimated glomerular filtration rate(e GFR,EPI)were assessed at baseline and at 1,3,5,and 10 years of follow-up.The efficacy of the Strengthening Spleen and Draining Dampness therapy was analyzed using repeated measures analysis of variance(ANOVA).Kaplan-Meier survival curves and multivariate proportional hazards model(Cox regression models)were employed to identify factors associated with treatment outcomes.RESULTS:A total of 265 patients were included,with a median follow-up duration of 96 months(36,122).TCM treatment significantly reduced 24-h urinary protein levels(P<0.001),and increased serum albumin levels(P<0.001),while serum creatinine remained stable(P=0.187).Remission rates at 1,3,5,and 10 years were 52.81%,69.71%,68.39%,and 72.36%,respectively,and the rates of avoiding composite outcome events at the same intervals were 98.27%,94.29%,94.19%,and 93.50%.In the subgroup receiving TCM only,remission rates were 56.67%,84.44%,76.32%,and 82.86%.For patients treated initially with Western Medicine followed by TCM,the rates were 52.83%,65.85%,67.47%and 67.75%.In the cohort of patients who received TCM as their first-line therapy,remission rates were 49.23%,62.50%,61.76%,and 69.23%.Multivariate Cox regression analysis revealed that the duration of TCM treatment[hazard ratio(HR)=0.826,95%confidence interval(CI)(0.779,0.876),P<0.001],presence of hypertension[HR=1.912,95%CI(1.181,3.094),P=0.008],baseline serum albumin level[HR=0.930,95%CI(0.894,0.969),P<0.001],and the rate of serum albumin increase within the first year of treatment[HR=0.930,95%CI(0.909,0.957),P<0.001]were significantly associated with clinical outcomes.CONCLUSION:The Strengthening Spleen and Draining Dampness therapy demonstrated robust short-and longterm efficacy in treating IMN,with high rates of remission and renal survival over 10 years.Key factors influencing clinical remission included the duration of TCM treatment,baseline serum albumin levels,the presence of hypertension,and the rate of increase in serum albumin within the first year.These findings suggest that this TCM approach provides a viable long-term treatment option for IMN.展开更多
Martensite is an important microstructure in ultrahigh-strength steels,and enhancing the strength of martensitic steels often involves the introduction of precipitated phases within the martensitic matrix.Despite cons...Martensite is an important microstructure in ultrahigh-strength steels,and enhancing the strength of martensitic steels often involves the introduction of precipitated phases within the martensitic matrix.Despite considerable research efforts devoted to this area,a systematic summary of these advancements is lacking.This review focuses on the precipitates prevalent in ultrahigh-strength martensitic steel,primarily carbides(e.g.,MC,M_(2)C,and M_(3)C)and intermetallic compounds(e.g.,Ni Al,Ni_(3)X,and Fe_(2)Mo).The precipitation-strengthening effect of these precipitates on ultrahigh-strength martensitic steel is discussed from the aspects of heat treatment processes,microstructure of precipitate-strengthened martensite matrix,and mechanical performance.Finally,a perspective on the development of precipitation-strengthened martensitic steel is presented to contribute to the advancement of ultrahigh-strength martensitic steel.This review highlights significant findings,ongoing challenges,and opportunities in the development of ultrahigh-strength martensitic steel.展开更多
93W-4.9Ni-2.1Fe alloys strengthened by nanoscale ZrC particles were prepared by spark-plasma-sintering(SPS)and hot rotary swaging,separately.Results show that the addition of a small number of ZrC nanoparticles can re...93W-4.9Ni-2.1Fe alloys strengthened by nanoscale ZrC particles were prepared by spark-plasma-sintering(SPS)and hot rotary swaging,separately.Results show that the addition of a small number of ZrC nanoparticles can refine grains and increase the hardness of the WNiFe alloys,but hinder the formation of theγ-(Ni,Fe)phase during SPS.SPSed WNiFe and WNiFe-ZrC alloys are brittle at room temperature,while the swaged WNiFe and WNiFe-0.5ZrC(wt%)alloys are ductile.At 400°C,the swaged WNiFe-0.5ZrC alloy exhibits both higher tensile strength and better ductility than the swaged WNiFe.The nanoscale particles distributed in the W grains andγ-(Ni,Fe)phase provide a good pinning effect,which enhances the strength.The thermal conductivity of swaged WNiFe-0.5ZrC is only 71 W·m^(-1)·K^(-1)at room temperature,but it increases to about 100 W·m^(-1)·K^(-1)at 800°C,which is close to that of pure W(121 W·m^(-1)·K^(-1)).These results show the potential of WNiFe alloys as plasma-facing materials in fusion reactor.展开更多
The extraordinary strength of metal/graphene composites is significantly determined by the characteristic size,distribution and morphology of graphene.However,the effect of the graphene size/distribution on the mechan...The extraordinary strength of metal/graphene composites is significantly determined by the characteristic size,distribution and morphology of graphene.However,the effect of the graphene size/distribution on the mechanical properties and related strengthening mechanisms has not been fully elucidated.Herein,under the same volume fraction and distribution conditions of graphene,molecular dynamics simulations were used to investigate the effect of graphene sheet size on the hardness and deformation behavior of Cu/graphene composites under complex stress field.Two models of pure single crystalline Cu and graphene fully covered Cu matrix composite were constructed for comparison.The results show that the strengthening effect changes with varying the graphene sheet size.Besides the graphene dislocation blocking effect and the load-bearing effect,the deformation mechanisms change from stacking fault tetrahedron,dislocation bypassing and dislocation cutting to dislocation nucleation in turn with decreasing the graphene sheet size.The hardness of Cu/graphene composite,with the graphene sheet not completely covering the metal matrix,can even be higher than that of the fully covered composite.The extra strengthening mechanisms of dislocation bypassing mechanism and the stacking fault tetrahedra pinning dislocation mechanism contribute to the increase in hardness.展开更多
The LPSO phase can effectively enhance the mechanical properties of Mg alloys.To investigate the impact of different LPSO phase contents and morphologies on the mechanical properties and strengthening mechanisms of Mg...The LPSO phase can effectively enhance the mechanical properties of Mg alloys.To investigate the impact of different LPSO phase contents and morphologies on the mechanical properties and strengthening mechanisms of Mg-Y-Al alloys under room temperature deformation,this study prepared Mg-12Y-1Al(WA121)alloys containing Bulk-LPSO(B-LPSO),Lattice-LPSO(L-LPSO),and Needle-like LPSO(N-LPSO)with different contents through different heat-treatment processes.The results indicate that with the increase in heat treatment time,the contents of B-LPSO phases remain essentially unchanged,and the contents of L-LPSO and N-LPSO phases gradually increase.The increase in N-LPSO phase content is the most pronounced,with the highest content(7.29%)observed in the alloy treated for 4.5 h.Moreover,the alloy treated for 4.5 h exhibits the best mechanical properties,with ultimate tensile strength(UTS),tensile yield strength(TYS),and elongation(EL)values of 177 MPa,139 MPa,and 4.27%,respectively.Compared to the as-cast alloy,UTS,TYS,and EL increased by 9.94%,11.2%,and 27.1%,respectively.The study reveals that all three LPSO phases exhibit excellent dislocation hindering effects,effectively enhancing strength of the alloy.Additionally,the N-LPSO phase,due to its dense distribution,forms numerous dislocation channels within the grains,dispersing stress concentration within the grains to improve plasticity of the alloy.Furthermore,the interaction between the N-LPSO phase and the other phases in the alloy can also enhance plasticity of the alloy.Therefore,the alloy treated for 4.5 h demonstrates a synergistic improvement in strength and plasticity.Research has revealed that the precipitation mechanism of the N-LPSO phase in the as-cast WA121 alloy involves the formation of an Al-rich region adjacent to the needle-like Mg_(24)Y_(5) phase.Subsequently,the Y element provided by the dissolving Mg_(24)Y_(5) phase reacts with this region,ultimately leading to the formation of the needle-like LPSO phase.展开更多
China and Myanmar are friendly neighbors connected by mountains and rivers,whose people have shared a friendship since ancient times so profound that it harnessed the term“Paukphaw,”a Burmese word for sibling.In Jan...China and Myanmar are friendly neighbors connected by mountains and rivers,whose people have shared a friendship since ancient times so profound that it harnessed the term“Paukphaw,”a Burmese word for sibling.In January 2020,leaders of the two countries announced a decision to build a China-Myanmar community with a shared future,and bilateral relations have since been strengthened even further,with cooperation continuously deepening across multiple fields.展开更多
As prestressed concrete(PC)structures age,long-termeffects,e.g.,creep,shrinkage,and prestress losses,compromise their structural performance.Strengthening these aged PC beams has become a crucial matter.One effective ...As prestressed concrete(PC)structures age,long-termeffects,e.g.,creep,shrinkage,and prestress losses,compromise their structural performance.Strengthening these aged PC beams has become a crucial matter.One effective solution is to use externally bonded fiber-reinforced polymer(FRP)sheets;however,limited research has been done on aged PC beams using the FRP,especially for beams with unbonded prestressing strands(UPC beams).Therefore,this research investigates the flexural strengthening efficacy of external FRP sheets on aged UPC beams with unbonded tendons.Aging minimally affected the failure modes of UPC beams,with nonstrengthened beams showing flexural failure via rebar yielding and concrete crushing,and FRP-strengthened beams failing due to FRP debonding and tensile reinforcement yielding,though tendons in the aged beams did not yield due to prestress losses,unlike the new beams.The U-wrap anchor curbed widespread debonding,leading to tensile reinforcement yielding and FRP rupture.Aging hastened crack growth and stiffness loss,increasing deflections and reducing load resistance,but FRP reinforcement mitigated these effects,enhancing cracking resistance by 14%over the unstrengthened aged beams and 7%over the new beams while boosting ultimate resistance by 9%above the non-strengthened new beams.Compared to the new FRP-strengthened beams,the aged counterparts had lower cracking resistance,stiffness and capacity—showing 20%higher deflections,7–9%lower serviceability loads,7%–17%reduced ultimate strength and 17%less deformability—due to prestress losses and premature FRP debonding.展开更多
The behavior of reinforced concrete(RC)square columns strengthened with self-compacting concrete(SCC)-filled steel tubes under cyclic loading was experimentally investigated.Tests were carried out on eleven reinforced...The behavior of reinforced concrete(RC)square columns strengthened with self-compacting concrete(SCC)-filled steel tubes under cyclic loading was experimentally investigated.Tests were carried out on eleven reinforced columns and one unreinforced column.The parameters studied for the strengthened columns included axial compression ratio,reinforcement rate,defect rate,strength of SCC,and the section form of a reinforced steel tube.The results show that the steel tube SCC reinforcement method can effectively strengthen RC columns,exert the restraint effect of steel tube,and delay the development of internal concrete cracks.The method can also significantly improve the bearing capacity of RC columns.Regarding ductility,the improvement of the reinforced column is obvious,the deformation resistance of the specimen is enhanced,and the degradation of stiffness and strength is relatively slow,indicating that it has good seismic performance.展开更多
This investigation examines the shear performance of concrete T-beams reinforced with thin layers of ultra-high performance concrete(UHPC)through an approach that integrates experimental evaluation,numerical simulatio...This investigation examines the shear performance of concrete T-beams reinforced with thin layers of ultra-high performance concrete(UHPC)through an approach that integrates experimental evaluation,numerical simulation,and practical project verification.The research is based on a real bridge,and in accordance with the similarity principle,three reduced-scale T-beams with varying UHPC thicknesses were fabricated and tested to examine their failure modes and shear behaviors.A finite element model was created to enhance understanding of how UHPC reinforces these structures,while also considering the effects of material strength and arrangement.In addition to the laboratory tests,the actual bridge was analyzed to assess the effectiveness of the proposed strengthening technique.Results indicated that concrete T-beams strengthened with 30 mm-thick layers of UHPC had significant improvements,including a 491%increase in shear stiffness,a 23.15%rise in ultimate resistance,and a 155%enhancement in deformability compared to unreinforced T-beams.Furthermore,these improvements continued to increase with the application of thicker UHPC layers.Using 120MPa-grade UHPC with a thickness of 50mmand an A-type arrangement ensured that the dynamic and static performance of the T-beambridge met established code requirements.This research highlights the potential of UHPC thin layers in effectively reinforcing concrete beams for enhanced shear performance.展开更多
The orientation of precipitates was regulated by an improved twinning-aging-detwinning(TAD)process in Mg-Sn sheets.A structure with specific proportions of dual-precipitates was regulated,significantly enhancing the m...The orientation of precipitates was regulated by an improved twinning-aging-detwinning(TAD)process in Mg-Sn sheets.A structure with specific proportions of dual-precipitates was regulated,significantly enhancing the material’s strength.The formation mechanism of the dual-precipitates was investigated,and the evolution of precipitate orientation was confirmed.A combined SEM,EBSD and TEM method was developed to identify the coupling relationship between complex grain orientation and precipitate orientation.The orientation relationship between precipitates and the matrix could be quantitatively analyzed in the same region.Subsequently,the Orowan model was refined to quantify the strength enhancement effect following the orientation regulation of precipitates.The TAD sample containing dual-precipitates exhibited a 99.1%increase in TYS,equivalent to an increase of 108 MPa,compared to unregulated samples A.According to Orowan calculations,the theoretical strength increment from the three strengthening mechanisms was 113 MPa,closely matching the experimental increment of 108 MPa.Notably,the materials with a specific proportion of the dual-precipitates showed a substantial increase in strength.展开更多
Last year marked the golden jubilee of Malaysia-China diplomatic relations—a milestone that underscored the enduring friendship and collaboration between the two nations.Over the past five decades,Malaysia and China ...Last year marked the golden jubilee of Malaysia-China diplomatic relations—a milestone that underscored the enduring friendship and collaboration between the two nations.Over the past five decades,Malaysia and China have overcome many challenges together,fostering strong bilateral ties built on mutual respect,economic cooperation,cultural exchange,and shared aspirations for regional peace and prosperity.展开更多
Launched in December 2021,the China-Laos Railway(CLR)has created ample opportunities for the development of Laos’crop production,food processing,and manufacturing.A powerful booster to infrastructure connectivity and...Launched in December 2021,the China-Laos Railway(CLR)has created ample opportunities for the development of Laos’crop production,food processing,and manufacturing.A powerful booster to infrastructure connectivity and trade relations between the two countries,the rail project has also opened a door for young people in Laos through vocational training and education cooperation,strengthening the bonds of friendship between the two peoples.展开更多
On March 24,the international symposium themed“Strengthen the Role of the United Nations and Promote Multilateralism”was held in Beijing.The event was hosted by the Ministry of Foreign Affairs of China,and supported...On March 24,the international symposium themed“Strengthen the Role of the United Nations and Promote Multilateralism”was held in Beijing.The event was hosted by the Ministry of Foreign Affairs of China,and supported by China Institute of International Studies(CIIS),the United Nations Association of China.展开更多
基金supported by the National Natural Science Foundation of China(Nos.52171166 and U20A20231)the Natural Science Foundation of Hunan Province,China(Nos.2024JJ2060 and 2024JJ5406)+1 种基金the Key Laboratory of Materials in Dynamic Extremes of Sichuan Province(No.2023SCKT1102)the Postgraduate Scientific Research Innovation Project of National University of Defense Technology(No.XJJC2024065).
文摘Introducing B2 ordering can effectively improve the mechanical properties of lightweight refractory high-entropy alloys(LRHEAs).However,(Zr,Al)-enriched B2 precipitates generally reduce the ductility because their ordering characteristic is destroyed after dislocation shearing.Meanwhile,the local chemical order(LCO)cannot provide an adequate strengthening effect due to its small size.
基金supported by the National Natural Science Foundation of China(No.51701242,51931012)the Science and Technology Innovation Program of Hunan Province(No.2023RC3068).
文摘As a typical tungsten-based composite consisting of tungsten(W)particles and matrix phase,tungsten heavy alloys(WHAs)are extensively utilized in the military due to their exceptional strength and high density.However,the large grain size(>30μm)of powder metallurgy liquid phase sintered(LPS)WHAs and the low strength of the matrix phase limit the further improvement of the alloy.In this work,high-density ultrafine WHAs were fabricated by two-step low-temperature sintering,and the density of the alloy reached 17 g/cm^(3) with an average W particle size of 7.81μm.Additionally,the eutectic reaction be-tween Ni and Ta was controlled to generate dispersed nano-Ni_(3)Ta phases in situ in the matrix phase,fur-ther improving the strength of the alloy.Under the synergistic strengthening effect of fine-grain strength-ening,dispersion strengthening,and solid solution strengthening,the average ultimate tensile strength of the alloy reached 1190.39 MPa.At the same time,the alloy maintained good elongation with a total elon-gation of 20.8%due to the good co-grid interface orientation between the Ni_(3)Ta phase and the matrix phase.This study provides a new idea for developing high-strength WHAs and has a guiding significance for developing Ni-based alloys.
基金financial support from the Na-tional Natural Science Foundation of China(No.52231006)National Key Research and Development Program of China(No.2017YFB0702003)the National Natural Science Foundation of China(No.51871217).
文摘Refractory high/medium-entropy alloys(RH/MEAs)are known for their outstanding performance at el-evated temperatures;however,they usually exhibit poor room-temperature plasticity,which can be at-tributed to the non-uniform deformation that occurs at room temperature.Once cracks nucleate,they will rapidly propagate into vertical splitting cracks.Here,we introduce multiple phases including FCC and HCP phases into the NbMoTa RMEA via appropriate addition of carbon.The results show that multiple-phase synergy effectively suppresses non-uniform deformation,thereby delaying the onset of vertical splitting cracks.An optimal combination of compressive strength-plasticity is achieved by the(NbMoTa)_(92.5)C_(7.5) alloy.The significant improvement in room-temperature mechanical properties can be attributed to its hierarchical microstructure:in the mesoscale,the BCC matrix is divided by eutectic structures;while at the microscale,the BCC matrix is further refined by abundant lath-like FCC precipitates.The FCC precip-itates contain high-density stacking faults,acting as a dislocation source under compressive loading.The HCP phase in the eutectic microstructures,in turn,acts as a strong barrier to dislocation movement and simultaneously increases the dislocation storage capacity.These findings open a new route to tailor the microstructure and mechanical properties of RH/MEAs.
基金support from the Natural Science Foundation of China(Nos.52104373,52074131,and 51974092)the Basic and Applied Basic Foundation of Guangdong Province(No.2020B1515120065)。
文摘This paper examines the effect of Fe addition on the microstructure characterized by scanning electron microscopy/electron backscattered diffraction,neutron diffraction,and synchrotron X-ray tomography and the mechanical properties of Al-Mg-Mn-Fe-Cu alloys.The findings reveal that the microstructures of the alloys consisted of an Al matrix,Al_(6)(FeMn),and Al_(2)CuMg phase particles.The addition of Fe significantly increased the yield strength(YS),and ultimate tensile strength(UTS)of the alloys,while reducing elongation.The transformation of the 3D morphology of the Al_(6)(FeMn)phase from separated and fine particles with Chinese-script morphology to interconnected rod-like structure as Fe content increased from 0.1%to 0.8%.This strengthening effect was attributed to the slip lines being blocked at the vicinity of the inter-connected Fe-rich phase,leading to grain rotation and dislocation density increment around the Fe-rich phase,ultimately improving the strength of the alloys.However,the Fe-rich phases and Al_(2)CuMg phases were found to be prone to cracking under tensile stress,resulting in decreased elongation of the alloys.This study provides a potential application in the design and manufacturing of new non-heat-treatable Al alloys for the automotive industry.
基金supported by the National Natural Science Foundation of China(Grant Nos.52275321 and 52205348)the Shandong Natural Science Foundation(Grant No.ZR2023JQ021)+3 种基金the Taishan Scholars Foundation of Shandong Province(No.tsqn 201812128)the Innovation Scientists and Technicians Troop Projects of Henan Province(No.204200510031)the Heilongjiang Touyan Innovation Team Program(No.HITTY-20190013)supported by the National Research Foundation of Korea(NRF)grant funded by the Korea government(MSIP)(Nos.NRF-2021R1A2C3006662 and NRF-2022R1A5A1030054).
文摘To effectively regulate the grain boundary infiltration in CoCrFeMnNi high-entropy alloy(Cantor alloys,HEA)caused by the violent atomic interdiffusion,the higher configuration entropy on Cantor alloys surface was designed and realized via eutectic high-entropy(EHEA)transformation.Meanwhile,to effectively alleviate the residual stress caused by the notable difference in the thermal expansion coefficient(CTE)between Cantor alloys and Zr-3 alloys,a cladding layer was applied to the HEA surface using laser cladding technology of Nb,followed by brazing to Zr-3 alloys with Zr63.2Cu filler.The cladding layer’s microstructure comprised Nbss and FCC+(Co,Ni)_(2) Nb eutectic structure,resulting from an in-situ reaction between Cantor alloys and Nb.The Nbss and FCC demonstrated good plasticity,and the(Co,Ni)_(2) Nb Laves phase provided increased strength,endowing both good plastic deformation ability and strength of the cladding layer.Notably,the existence of EHEA in the laser cladding layer made the Cantor alloy entropy from 1.61 R to 1.77 R,greatly enhancing its thermal stability and suppressing the grave grain boundary infiltration.Joints produced via laser cladding with Nb-assisted brazing exhibited a complex microstructure(HEA/Nbss+FCC+(Co,Ni)_(2)Nb/(Zr,Nb)(Cr,Mn)_(2)+(Zr,Nb)ss/(Zr,Nb)_(2)(Cu,Ni,Co,Fe)+(Zr,Nb)(Cr,Mn)_(2)+(Zr,Nb)ss/Zr-3) and a significantly improved shear strength of 242.8 MPa at 1010℃ for 10 min,42.4%higher than that of directly brazed joints.This improvement was attributed to reduced grain boundary infiltration,alleviated residual stress due to CTE disparity,and eliminated micro-cracks in the brazing seam.This study presents an effective solution for reducing residual stresses and achieving reliable bonding between Cantor alloys and Zr-3 alloys,with potential applications in brazing CoCrFeNi-based HEA and Zr-3 due to the beneficial eutectic reaction between CoCrFeNi and Nb.
基金financially supported by the Natural Science Basic Research Program of Shaanxi Province,China(No.2023-JC-QN-0581)Advanced Power Specialty,China(No.YK22C-9)。
文摘The microstructure evolution and strengthening mechanism of WE54 alloy with different hard-plate rolling(HPR)processes were systematically investigated.The results suggest that the mechanical properties of the as-rolled alloys are significantly enhanced compared to those of the as-cast alloy.When subjected to three rolling passes at 450℃ and 490℃,grain refinement occurs due to dynamic recrystallization.A mixed-grain structure is formed after a single pass rolling with a substantial reduction(65%)at 490℃.The dynamic recrystallization(DRX)mechanism of the alloy during the HPR includes continuous dynamic recrystallization(CDRX),discontinuous dynamic recrystallization(DDRX),and twin-induced recrystallization(TDRX).The WE54 alloy exhibits the highest strength after three passes of HPR at 450℃,with tensile strength and yield strength of 374 and 323 MPa,respectively.The significant improvement in the mechanical properties of the alloy is primarily attributed to fine-grain strengthening,solid solution strengthening,and dislocation strengthening.
基金supported by the National Natural Science Foundation of China(Grant No.U2341254)the National Natural Science Foundation of China(Grant No.52071124),the Natural Science Foundation of Jiangsu Province(No.BK20230502)the Jiangsu Funding Program for Excellent Postdoctoral Talent(No.2022ZB547).
文摘The unique structure and formation mechanism of medium-entropy alloys(MEAs)generally result in bet-ter comprehensive properties than traditional alloys.However,the strength-ductility trade-offremains a bottleneck,which limits their applications.In this study,we designed novel high-performance CrNiCu x MEAs with a heterophase composition by incorporating a Cu-rich phase,and they were fabricated using laser-directed energy deposition(LDED).The results show that synergistic strengthening from multiple phases significantly improved the mechanical properties of the alloys,resulting in a tensile strength of 675 MPa and a ductility of 34.4%,demonstrating an excellent combination of high tensile strength and ductility.The improved mechanical properties of the CrNiCu x medium-entropy alloys are primarily due to the heterophase interfacial strengthening mechanism.In the alloy,numerous semi-coherent and coher-ent interfaces formed between the Cr-rich phase,Cu-rich phase,and the matrix,creating extensive lattice distortions at the interfaces.An increase in the Cu-rich phase content promoted the interaction between phases,enhancing the strain energy of the alloy and the barrier strength of the interfaces.The calcu-latedτint values,ranging from approximately 5.92-6.69 GPa,are significantly higher than those found in traditional alloys,providing a benchmark for designing new high-performance medium-entropy alloys.
基金Supported by the National Key Research and Development Project,Clinical Study on the Treatment of Refractory Membranous Nephropathy with the Treatment of Strengthening Spleen and Draining Dampness in Method using Single Group Target Value Method(No.2019YFC1709403)Systematic Study on the Diagnosis and Treatment Rules of Membranous Nephropathy in Traditional Chinese Medicine(No.2023YFC35033501,No.2023YFC35033503)。
文摘OBJECTIVE:To evaluate the 10-year therapeutic efficacy of Traditional Chinese Medicine(TCM)using the Strengthening Spleen and Draining Dampness therapy in the management of idiopathic membranous nephropathy(IMN).METHODS:A single-center,retrospective analysis was conducted on patients diagnosed with IMN who met predefined inclusion and exclusion criteria.Data were collected from the Department of Nephrology at Longhua Hospital,affiliated with Shanghai University of Traditional Chinese Medicine,between January 2007 and December 2011.Clinical parameters including 24-h urinary protein,serum albumin,serum creatinine,and estimated glomerular filtration rate(e GFR,EPI)were assessed at baseline and at 1,3,5,and 10 years of follow-up.The efficacy of the Strengthening Spleen and Draining Dampness therapy was analyzed using repeated measures analysis of variance(ANOVA).Kaplan-Meier survival curves and multivariate proportional hazards model(Cox regression models)were employed to identify factors associated with treatment outcomes.RESULTS:A total of 265 patients were included,with a median follow-up duration of 96 months(36,122).TCM treatment significantly reduced 24-h urinary protein levels(P<0.001),and increased serum albumin levels(P<0.001),while serum creatinine remained stable(P=0.187).Remission rates at 1,3,5,and 10 years were 52.81%,69.71%,68.39%,and 72.36%,respectively,and the rates of avoiding composite outcome events at the same intervals were 98.27%,94.29%,94.19%,and 93.50%.In the subgroup receiving TCM only,remission rates were 56.67%,84.44%,76.32%,and 82.86%.For patients treated initially with Western Medicine followed by TCM,the rates were 52.83%,65.85%,67.47%and 67.75%.In the cohort of patients who received TCM as their first-line therapy,remission rates were 49.23%,62.50%,61.76%,and 69.23%.Multivariate Cox regression analysis revealed that the duration of TCM treatment[hazard ratio(HR)=0.826,95%confidence interval(CI)(0.779,0.876),P<0.001],presence of hypertension[HR=1.912,95%CI(1.181,3.094),P=0.008],baseline serum albumin level[HR=0.930,95%CI(0.894,0.969),P<0.001],and the rate of serum albumin increase within the first year of treatment[HR=0.930,95%CI(0.909,0.957),P<0.001]were significantly associated with clinical outcomes.CONCLUSION:The Strengthening Spleen and Draining Dampness therapy demonstrated robust short-and longterm efficacy in treating IMN,with high rates of remission and renal survival over 10 years.Key factors influencing clinical remission included the duration of TCM treatment,baseline serum albumin levels,the presence of hypertension,and the rate of increase in serum albumin within the first year.These findings suggest that this TCM approach provides a viable long-term treatment option for IMN.
基金supported by the National Natural Science Foundation of China(Nos.52122408 and 52071023)financial support from the Fundamental Research Funds for the Central Universities(University of Science and Technology Beijing,No.FRF-TP-2021-04C1,and 06500135)。
文摘Martensite is an important microstructure in ultrahigh-strength steels,and enhancing the strength of martensitic steels often involves the introduction of precipitated phases within the martensitic matrix.Despite considerable research efforts devoted to this area,a systematic summary of these advancements is lacking.This review focuses on the precipitates prevalent in ultrahigh-strength martensitic steel,primarily carbides(e.g.,MC,M_(2)C,and M_(3)C)and intermetallic compounds(e.g.,Ni Al,Ni_(3)X,and Fe_(2)Mo).The precipitation-strengthening effect of these precipitates on ultrahigh-strength martensitic steel is discussed from the aspects of heat treatment processes,microstructure of precipitate-strengthened martensite matrix,and mechanical performance.Finally,a perspective on the development of precipitation-strengthened martensitic steel is presented to contribute to the advancement of ultrahigh-strength martensitic steel.This review highlights significant findings,ongoing challenges,and opportunities in the development of ultrahigh-strength martensitic steel.
基金National Key Research and Development Program of China(2022YFE03140002,2019YFE03110200)National Natural Science Foundation of China(52273320,52173303,52325103,52171084)+2 种基金Strategic Priority Research Program of the Chinese Academy of Sciences(XDB0470000)Anhui Provincial Natural Science Foundation(2308085J07)HFIPS Director's Fund(YZJJ202102,YZJJQY202306,YZJJKX202202)。
文摘93W-4.9Ni-2.1Fe alloys strengthened by nanoscale ZrC particles were prepared by spark-plasma-sintering(SPS)and hot rotary swaging,separately.Results show that the addition of a small number of ZrC nanoparticles can refine grains and increase the hardness of the WNiFe alloys,but hinder the formation of theγ-(Ni,Fe)phase during SPS.SPSed WNiFe and WNiFe-ZrC alloys are brittle at room temperature,while the swaged WNiFe and WNiFe-0.5ZrC(wt%)alloys are ductile.At 400°C,the swaged WNiFe-0.5ZrC alloy exhibits both higher tensile strength and better ductility than the swaged WNiFe.The nanoscale particles distributed in the W grains andγ-(Ni,Fe)phase provide a good pinning effect,which enhances the strength.The thermal conductivity of swaged WNiFe-0.5ZrC is only 71 W·m^(-1)·K^(-1)at room temperature,but it increases to about 100 W·m^(-1)·K^(-1)at 800°C,which is close to that of pure W(121 W·m^(-1)·K^(-1)).These results show the potential of WNiFe alloys as plasma-facing materials in fusion reactor.
基金Foundation of Northwest Institute for Nonferrous Metal Research(ZZXJ2203)Capital Projects of Financial Department of Shaanxi Province(YK22C-12)+3 种基金Innovation Capability Support Plan in Shaanxi Province(2023KJXX-083)Key Research and Development Projects of Shaanxi Province(2024GXYBXM-351,2024GX-YBXM-356)National Natural Science Foundation of China(62204207,12204383)Xi'an Postdoctoral Innovation Base Funding Program。
文摘The extraordinary strength of metal/graphene composites is significantly determined by the characteristic size,distribution and morphology of graphene.However,the effect of the graphene size/distribution on the mechanical properties and related strengthening mechanisms has not been fully elucidated.Herein,under the same volume fraction and distribution conditions of graphene,molecular dynamics simulations were used to investigate the effect of graphene sheet size on the hardness and deformation behavior of Cu/graphene composites under complex stress field.Two models of pure single crystalline Cu and graphene fully covered Cu matrix composite were constructed for comparison.The results show that the strengthening effect changes with varying the graphene sheet size.Besides the graphene dislocation blocking effect and the load-bearing effect,the deformation mechanisms change from stacking fault tetrahedron,dislocation bypassing and dislocation cutting to dislocation nucleation in turn with decreasing the graphene sheet size.The hardness of Cu/graphene composite,with the graphene sheet not completely covering the metal matrix,can even be higher than that of the fully covered composite.The extra strengthening mechanisms of dislocation bypassing mechanism and the stacking fault tetrahedra pinning dislocation mechanism contribute to the increase in hardness.
基金supported by the Qinghai Provincial Science and Technology Department Basic Research Program(No.2025ZY029).
文摘The LPSO phase can effectively enhance the mechanical properties of Mg alloys.To investigate the impact of different LPSO phase contents and morphologies on the mechanical properties and strengthening mechanisms of Mg-Y-Al alloys under room temperature deformation,this study prepared Mg-12Y-1Al(WA121)alloys containing Bulk-LPSO(B-LPSO),Lattice-LPSO(L-LPSO),and Needle-like LPSO(N-LPSO)with different contents through different heat-treatment processes.The results indicate that with the increase in heat treatment time,the contents of B-LPSO phases remain essentially unchanged,and the contents of L-LPSO and N-LPSO phases gradually increase.The increase in N-LPSO phase content is the most pronounced,with the highest content(7.29%)observed in the alloy treated for 4.5 h.Moreover,the alloy treated for 4.5 h exhibits the best mechanical properties,with ultimate tensile strength(UTS),tensile yield strength(TYS),and elongation(EL)values of 177 MPa,139 MPa,and 4.27%,respectively.Compared to the as-cast alloy,UTS,TYS,and EL increased by 9.94%,11.2%,and 27.1%,respectively.The study reveals that all three LPSO phases exhibit excellent dislocation hindering effects,effectively enhancing strength of the alloy.Additionally,the N-LPSO phase,due to its dense distribution,forms numerous dislocation channels within the grains,dispersing stress concentration within the grains to improve plasticity of the alloy.Furthermore,the interaction between the N-LPSO phase and the other phases in the alloy can also enhance plasticity of the alloy.Therefore,the alloy treated for 4.5 h demonstrates a synergistic improvement in strength and plasticity.Research has revealed that the precipitation mechanism of the N-LPSO phase in the as-cast WA121 alloy involves the formation of an Al-rich region adjacent to the needle-like Mg_(24)Y_(5) phase.Subsequently,the Y element provided by the dissolving Mg_(24)Y_(5) phase reacts with this region,ultimately leading to the formation of the needle-like LPSO phase.
文摘China and Myanmar are friendly neighbors connected by mountains and rivers,whose people have shared a friendship since ancient times so profound that it harnessed the term“Paukphaw,”a Burmese word for sibling.In January 2020,leaders of the two countries announced a decision to build a China-Myanmar community with a shared future,and bilateral relations have since been strengthened even further,with cooperation continuously deepening across multiple fields.
基金support by the Ministry of Education and Training of Vietnam for this research,under grant no.B2023-MBS-02.
文摘As prestressed concrete(PC)structures age,long-termeffects,e.g.,creep,shrinkage,and prestress losses,compromise their structural performance.Strengthening these aged PC beams has become a crucial matter.One effective solution is to use externally bonded fiber-reinforced polymer(FRP)sheets;however,limited research has been done on aged PC beams using the FRP,especially for beams with unbonded prestressing strands(UPC beams).Therefore,this research investigates the flexural strengthening efficacy of external FRP sheets on aged UPC beams with unbonded tendons.Aging minimally affected the failure modes of UPC beams,with nonstrengthened beams showing flexural failure via rebar yielding and concrete crushing,and FRP-strengthened beams failing due to FRP debonding and tensile reinforcement yielding,though tendons in the aged beams did not yield due to prestress losses,unlike the new beams.The U-wrap anchor curbed widespread debonding,leading to tensile reinforcement yielding and FRP rupture.Aging hastened crack growth and stiffness loss,increasing deflections and reducing load resistance,but FRP reinforcement mitigated these effects,enhancing cracking resistance by 14%over the unstrengthened aged beams and 7%over the new beams while boosting ultimate resistance by 9%above the non-strengthened new beams.Compared to the new FRP-strengthened beams,the aged counterparts had lower cracking resistance,stiffness and capacity—showing 20%higher deflections,7–9%lower serviceability loads,7%–17%reduced ultimate strength and 17%less deformability—due to prestress losses and premature FRP debonding.
基金Natural Science Foundation of Sichuan Province under Grant Nos.2022NSFSC0319 and 2022NSFSC0095the Science and Technology Research Projects of Mianyang,China under Grant No.15S-02-3。
文摘The behavior of reinforced concrete(RC)square columns strengthened with self-compacting concrete(SCC)-filled steel tubes under cyclic loading was experimentally investigated.Tests were carried out on eleven reinforced columns and one unreinforced column.The parameters studied for the strengthened columns included axial compression ratio,reinforcement rate,defect rate,strength of SCC,and the section form of a reinforced steel tube.The results show that the steel tube SCC reinforcement method can effectively strengthen RC columns,exert the restraint effect of steel tube,and delay the development of internal concrete cracks.The method can also significantly improve the bearing capacity of RC columns.Regarding ductility,the improvement of the reinforced column is obvious,the deformation resistance of the specimen is enhanced,and the degradation of stiffness and strength is relatively slow,indicating that it has good seismic performance.
基金The Science and Technology Project of Guangzhou(Grant#2024A04J9888)the National Natural Science Foundation of China(Grant#52278161)the Guangdong Basic and Applied Basic Research Foundation(Grant#2023A1515010535).
文摘This investigation examines the shear performance of concrete T-beams reinforced with thin layers of ultra-high performance concrete(UHPC)through an approach that integrates experimental evaluation,numerical simulation,and practical project verification.The research is based on a real bridge,and in accordance with the similarity principle,three reduced-scale T-beams with varying UHPC thicknesses were fabricated and tested to examine their failure modes and shear behaviors.A finite element model was created to enhance understanding of how UHPC reinforces these structures,while also considering the effects of material strength and arrangement.In addition to the laboratory tests,the actual bridge was analyzed to assess the effectiveness of the proposed strengthening technique.Results indicated that concrete T-beams strengthened with 30 mm-thick layers of UHPC had significant improvements,including a 491%increase in shear stiffness,a 23.15%rise in ultimate resistance,and a 155%enhancement in deformability compared to unreinforced T-beams.Furthermore,these improvements continued to increase with the application of thicker UHPC layers.Using 120MPa-grade UHPC with a thickness of 50mmand an A-type arrangement ensured that the dynamic and static performance of the T-beambridge met established code requirements.This research highlights the potential of UHPC thin layers in effectively reinforcing concrete beams for enhanced shear performance.
基金National Natural Science Foundation of China(52374405)Joint Innovaion Fund Project of Lanzhou Jiaotong University and Corresponding Supporting University(LH2024018)State Key Laboratory Open Project(Q110824Q02001)。
文摘The orientation of precipitates was regulated by an improved twinning-aging-detwinning(TAD)process in Mg-Sn sheets.A structure with specific proportions of dual-precipitates was regulated,significantly enhancing the material’s strength.The formation mechanism of the dual-precipitates was investigated,and the evolution of precipitate orientation was confirmed.A combined SEM,EBSD and TEM method was developed to identify the coupling relationship between complex grain orientation and precipitate orientation.The orientation relationship between precipitates and the matrix could be quantitatively analyzed in the same region.Subsequently,the Orowan model was refined to quantify the strength enhancement effect following the orientation regulation of precipitates.The TAD sample containing dual-precipitates exhibited a 99.1%increase in TYS,equivalent to an increase of 108 MPa,compared to unregulated samples A.According to Orowan calculations,the theoretical strength increment from the three strengthening mechanisms was 113 MPa,closely matching the experimental increment of 108 MPa.Notably,the materials with a specific proportion of the dual-precipitates showed a substantial increase in strength.
文摘Last year marked the golden jubilee of Malaysia-China diplomatic relations—a milestone that underscored the enduring friendship and collaboration between the two nations.Over the past five decades,Malaysia and China have overcome many challenges together,fostering strong bilateral ties built on mutual respect,economic cooperation,cultural exchange,and shared aspirations for regional peace and prosperity.
文摘Launched in December 2021,the China-Laos Railway(CLR)has created ample opportunities for the development of Laos’crop production,food processing,and manufacturing.A powerful booster to infrastructure connectivity and trade relations between the two countries,the rail project has also opened a door for young people in Laos through vocational training and education cooperation,strengthening the bonds of friendship between the two peoples.
文摘On March 24,the international symposium themed“Strengthen the Role of the United Nations and Promote Multilateralism”was held in Beijing.The event was hosted by the Ministry of Foreign Affairs of China,and supported by China Institute of International Studies(CIIS),the United Nations Association of China.
