Beryllium-containing sludge(BCS)is a typical hazardous waste from Be smelting,which can cause serious harm to ecology and human health by releasing harmful Be if it is stored long-term in environment.Nonetheless,the o...Beryllium-containing sludge(BCS)is a typical hazardous waste from Be smelting,which can cause serious harm to ecology and human health by releasing harmful Be if it is stored long-term in environment.Nonetheless,the occurrence of Be in BCS is unclear,which seriously hinders the development of pollution control technologies.In order to enhance the understanding of BCS,the occurrence of Be and the microscale interactions with coexisting phases were investigated for the first time.It was found that CaSO_(4)·2H_(2)O and amorphous SiO_(2) are the primary phases of BCS.The simulated experiments of purified materials showed that Be interacted with CaSO_(4)·2H_(2)O and amorphous SiO_(2).Be can enter into the lattice of CaSO_(4)·2H_(2)O mainly as free Be2+.Amorphous SiO_(2) can adsorb Be2+particularly at a pH range of 3–5.The dissolution behavior experiment of BCS shows that about 52%of the Be is readily extracted under acidic conditions,which refers to the Be of independent occurrence.In contrast,the remaining 48%of Be can be extracted only after the CaSO_(4)·2H_(2)O has completely dissolved.Hence,CaSO_(4)·2H_(2)O is identified as the key occurrence phase which determines the highly efficient dissolution of Be.As a result,this study enhances the understanding of BCS and lays the foundation for the development of Be separation technologies.展开更多
Objective:To evaluate the effectiveness of surgical combination with traditional Chinese medicine dialectical therapy in three phases for the treatment of intertrochanteric fracture of the femur(IFF).Methods:84 patien...Objective:To evaluate the effectiveness of surgical combination with traditional Chinese medicine dialectical therapy in three phases for the treatment of intertrochanteric fracture of the femur(IFF).Methods:84 patients with IFF admitted to the hospital from December 2022 to December 2024 were selected and randomly divided into two groups using a random number table.The combined group received surgery and traditional Chinese medicine dialectical therapy in three phases,while the control group received surgery alone.The total effective rate,fracture healing time,hip function score,and lower extremity function score were compared between the two groups.Results:The total effective rate was higher in the combined group than in the control group(P<0.05).After treatment,the fracture healing time was shorter in the combined group than in the control group,and the hip function and lower extremity function scores were higher in the combined group than in the control group(P<0.05).Conclusion:Surgical combination with traditional Chinese medicine dialectical therapy in three phases can shorten the fracture healing time of IFF patients and restore their hip and lower extremity function,demonstrating significant efficacy.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
Microstructural characterization,mass loss tests,hydrogen evolution tests,electrochemical measurements,and corrosion morphology observations were conducted to investigate the effect of the secondary phases on the corr...Microstructural characterization,mass loss tests,hydrogen evolution tests,electrochemical measurements,and corrosion morphology observations were conducted to investigate the effect of the secondary phases on the corrosion behavior of the as-cast Mg−7Sn−1Zn−1Y(TZW711)alloy after solution treatment(T4)and aging treatment(T6).The results show that the T4-TZW711 alloy possesses the highest corrosion resistance in the early corrosion stage.This is because the dissolution of Mg2Sn reduces the cathodic current density and increases the charge transfer resistance(Rct).When the corrosion time is prolonged,the undissolved and clustered MgSnY phase will peel off from the T4-TZW711 alloy surface,thereby increasing the corrosion rate of the alloy.After aging treatment,the undissolved MgSnY phase is dispersed,which results in a lower localized corrosion sensitivity of T6-TZW711 alloy than that of the T4-TZW711 alloy,suggesting that the T6 treatment can enhance the corrosion resistance of Mg−7Sn−1Zn−1Y alloys.展开更多
In secondary Al-Si based alloys,microalloying with Mn and Cr can modify harmful platelet-type Alx Fey Siz intermetallic phases to less detrimentalα-Alx(Fe,Mn,Cr)_(y)Siz phase(script or polygonal morphologies).However...In secondary Al-Si based alloys,microalloying with Mn and Cr can modify harmful platelet-type Alx Fey Siz intermetallic phases to less detrimentalα-Alx(Fe,Mn,Cr)_(y)Siz phase(script or polygonal morphologies).However,theα-Alx(Fe,Mn,Cr)_(y)Siz phase morphology,phase composition and the addition of Fecorrecting elements can be influenced by solidification conditions.Therefore,this research is aimed to highlight the morphological evolution and mechanisms ofα-Alx(Fe,Mn,Cr)_(y)Si_(z)phase in a Cr added Al-9%Si-1%Fe-0.2%Cr(all weight percentage thereafter,unless otherwise stated)alloy with varying Mn concentrations(0.25%,0.5%,and 0.8%).Microstructure evolution of Fe intermetallic phases is investi-gated under different casting conditions using a wedge-shaped die,Cu-chill block and melt quenching experiments.Thermodynamic simulations have been performed using CALculation of PHAse Diagrams(CALPHAD)method and compared with the experimental results for phase composition and formation temperatures ofα-Alx(Fe,Mn,Cr)_(y)Siz phase.The results indicated that for 0.25Mn-0.2Cr addition to Al-9Si-1Fe alloy,compact morphology containing polygonal phases are formed in Cu-chill casting,while the wedge castings predominantly show a mixed structure with platelets and script type morphologies.Tensile tests revealed a higher elongation value of 6.6%for mixed structure with platelet and script phases,which is decreased to 4.2%for polygonal phases in Al-9Si-1Fe-0.2Cr-0.25Mn alloy.This study highlights the importance of solidification conditions on morphologies of Fe-intermetallic phases and the mechanical properties by comparing selected literature relevant to high pressure die-casting process.展开更多
In this study,friction stir processing(FSP)was employed to modify the as-cast Mg-14Gd-0.6Ce-0.5Zr alloy,and the effects of texture evolution and distribution of second phases on mechanical properties were systematical...In this study,friction stir processing(FSP)was employed to modify the as-cast Mg-14Gd-0.6Ce-0.5Zr alloy,and the effects of texture evolution and distribution of second phases on mechanical properties were systematically investigated.The results show that friction stir processing effectively refined the coarse Mg_(5)Gd phases into nanoscale second phases uniformly distributed along grain boundaries.The synergistic effect of texture weakening and second phases refinement significantly enhanced the tensile strength and elongation of the FSP-1000-120 alloy to 302.1 MPa and 18.3%,respectively,representing increases of 20.8%and 281.3%compared to the as-cast alloy.The as-cast alloy has a lower corrosion rate in the initial stage due to fewer micro-galvanic corrosion sites.However,the uniform distribution of the second phase in the FSP-treated(FSPed)alloy contributes to the formation of a more complete and dense corrosion product film.After 120 h of immersion,the as-cast alloy forms deep pits due to the continuous dissolution at the second phase-matrix interface,with the average corrosion rate increasing from 0.31 to 0.47 mL/cm^(2)/h.The long-term corrosion rates of FSP-1000-60,FSP-1000-120,and FSP-1200-120 samples are stable at 0.36,0.43,and 0.50 mL/cm^(2)/h,respectively.Research reveals that FSP regulates texture and second phase distribution to achieve synergistic strengthening of alloy strength plasticity,and the homogenization of second phase distribution is a key factor in improving the long-term corrosion resistance of alloys.展开更多
The precipitation of secondary Laves phases and its effect on notch sensitivity are systematically studied in Thermo-Span alloy. The results show that the precipitation peak temperature of secondary Laves phases is 9...The precipitation of secondary Laves phases and its effect on notch sensitivity are systematically studied in Thermo-Span alloy. The results show that the precipitation peak temperature of secondary Laves phases is 925 ℃. Below 925 ℃, the volume fraction of secondary Laves phases increases with the rise of the temperature, and its morphology changes from granular to thin-film;above 925 ℃, the volume fraction of secondary Laves phases shows an opposite trend to temperature, and its morphology changes from thin-film to granular. A detailed explanation through linear density (ρ) is provided that the influence of secondary Laves phases at the grain boundaries (GBs) on notch sensitivity depends on the coupling competition effect of their size, quantity, and morphology. Notably, the granular Laves phases are more beneficial to improving the notch sensitivity of the alloy compared with thin-film Laves phases. Granular secondary Laves phases can promote the formation of γ′ phases depletion zone to improve the ability of GBs to accommodate high strain localization, and effectively inhibit the crack initiation and propagation.展开更多
1.Introduction Compared with the widely used vapor-compression refrigeration,solid-state cooling based on phase transition offers higher ef-ficiency,environmental friendliness,and smaller volume[1,2].The phase transit...1.Introduction Compared with the widely used vapor-compression refrigeration,solid-state cooling based on phase transition offers higher ef-ficiency,environmental friendliness,and smaller volume[1,2].The phase transition of solid refrigerants can be triggered by external fields,i.e.,magnetic fields[3-5],electric fields[6,7].展开更多
Rapid urbanization reshapes landscape patterns and intensifies stormwater runoff pressure,yet the shifting cost-effectiveness of green infrastructure across different urban development phases remains poorly quantified...Rapid urbanization reshapes landscape patterns and intensifies stormwater runoff pressure,yet the shifting cost-effectiveness of green infrastructure across different urban development phases remains poorly quantified.Focusing on Beijing’s 150 km2 urban subcenter,this study quantified 21 block-level landscape metrics,which were distilled via principal component analysis into five landform indicators:dominance,fragmentation,edge,aggregation,and shape.K-means clustering classified each block into constructed,constructing,or unconstructed phases.A life-cycle cost analysis then estimated the bioretention investment required to meet an 80%-85%annual runoff volume control target.The constructing phase,characterized by contiguous impervious surfaces at the urban edge,demands 45%more bioretention investment per unit area than the unconstructed phase and 4%more than the constructed phase.As land transitions from unconstructed to constructed,bioretention costs increase by approximately 109%for agricultural land and 86%for green space,whereas changes for residential and commercial areas remain minimal.These results indicate that uniform runoff control investment policies risk underfunding rapidly developing fringes and overfunding consolidated urban centers.A phase-specific and land use-sensitive investment strategy is therefore necessary to avoid capital inefficiency while achieving runoff control goals.By linking dynamic landscape evolution with infrastructure economics,this study provides a forward-looking tool to guide runoff control investment during urban expansion.展开更多
In the energy industry landscape,thermal power generation stands as a critical energy supply method,and the safety of its construction and operation is paramount.Currently,all stages of the life cycle of construction ...In the energy industry landscape,thermal power generation stands as a critical energy supply method,and the safety of its construction and operation is paramount.Currently,all stages of the life cycle of construction projects have garnered widespread attention.Among these,the infrastructure construction and operation phases of thermal power generation enterprises pose numerous issues worthy of in-depth study in terms of safety production management.This article starts by examining safety production management during these two phases,analyzing characteristics such as management models,legal bases,and responsible entities.It explores the reasons behind these characteristics and elaborates on key management priorities,providing a comprehensive and insightful reference for safety production management in thermal power generation enterprises.展开更多
The addition of Ce significantly enhances cleanliness of steel and modifies precipitation phases.However,there are differences in the effects of different alloy systems,especially its role in M54 steel is insufficient...The addition of Ce significantly enhances cleanliness of steel and modifies precipitation phases.However,there are differences in the effects of different alloy systems,especially its role in M54 steel is insufficiently understood.This study investigates the evolution of inclusions and precipitation phases in M54 steel ingots with varying Ce additions.Results indicate that the addition of Ce reduces the content of impurity elements(O and S)and transforms Mg and Al inclusions into Ce inclusions,which is due to the stronger affinity between Ce and impurity elements such as O and S.Ce inclusions serve as nucleation sites for dendrites,reducing secondary dendrite arm spacing.In addition,these inclusions and Cecontaining precipitated phase also act as nucleation sites for carbide precipitates,effectively refining their distribution by reducing growth spaces and increasing nucleation density.Notably,as Ce content increases from 0 to 0.01 wt%,the precipitation phase content decreases significantly but rises slightly with further increases in Ce content due to the formation of additional Ce-containing precipitates.By quantitatively comparing the dendrite arm spacing,cleanliness,content and size of precipitated phase,it is determined that the optimum addition amount of Ce for M54 steel is about 0.01 wt%.展开更多
Machine learning has rapidly become a powerful tool for addressing challenges in ultracold atomic systems;however,its application to intricate three-dimensional(3D)systems remains relatively underexplored.In this stud...Machine learning has rapidly become a powerful tool for addressing challenges in ultracold atomic systems;however,its application to intricate three-dimensional(3D)systems remains relatively underexplored.In this study,we introduce a3D residual network(3D Res Net)framework based on 3D convolutional neural networks(3D CNN)to predict ground states phases in 3D dipolar spinor Bose–Einstein condensates(BECs).Our results show that the 3D Res Net framework predicts ground states with high accuracy and efficiency across a broad parameter space.To enhance phase transition predictions,we incorporate data augmentation techniques,leading to a notable improvement in the model's performance.The method is further validated in more complex scenarios,particularly when transverse magnetic fields are introduced.Compared to conventional imaginary-time evolution methods(ITEM),the 3D Res Net drastically reduces computational costs,offering a rapid and scalable solution for complex 3D multi-parameter nonlinear systems.展开更多
For chromatographic separation,the reasonable modulation of stationary phases is the key factor to achieve high separation performance.We proposed that developing MOF stationary phases through precisely modulating the...For chromatographic separation,the reasonable modulation of stationary phases is the key factor to achieve high separation performance.We proposed that developing MOF stationary phases through precisely modulating the thermodynamic interactions between MOFs and analytes is conducive to improving the separation resolution.MIL-125,MIL-125-NH_(2),MIL-143-BTB,and MIL-143-TATB were developed as stationary phases with the careful modulation of organic ligands.MIL-125-NH_(2)and MIL-143-TATB coated columns exhibited much better separation performance than their counterparts,MIL-125 and MIL-143-BTB,respectively.The investigation of the separation mechanism indicated that thermodynamic interaction,rather than kinetic diffusion,was responsible for the separation improvement.MIL-125-NH_(2)and MIL-143-TATB provided stronger and distinguishable interactions with targets than corresponding MIL-125 and MIL-143-BTB,respectively,resulting in enhanced separation performance.This work demonstrates a guide to improving the separation performance of MOF stationary phases by increasing the thermodynamic interactions between MOFs and analytes.展开更多
A mathematical model coupling flow,solidification,strain-stress,and interface failure was developed.Following identification of crack source type through thermal tensile experiment and validation by strain-stress comp...A mathematical model coupling flow,solidification,strain-stress,and interface failure was developed.Following identification of crack source type through thermal tensile experiment and validation by strain-stress comparison,the model was used to investigate slab cracking tendency near precipitated phases,considering various locations,sizes and shapes of them.The results show that the jet from submerged entry nozzle creates a“double roll”flow pattern during continuous casting,resulting in more uniform temperature distributions at slab corner and wide surface center compared with narrow surface center.Consequently,precipitated phases,particularly those located on the narrow surface,readily induce stress concentration and thus increase cracking tendency.A smaller precipitated phase size can reduce the stress concentration zone,while a more spherical shape can distribute surrounding stress along its surface and lower the internal stress within it,thereby decreasing the risk of slab cracking during continuous casting.The optimal precipitated phase exhibits a spherical or ellipsoidal shape with a major axis of less than 5µm,minimizing its potential to initiate cracks.展开更多
Tungsten carbide-based(WC-based)cemented carbides are widely recognized as high-performance tool materials.Traditionally,single metals such as cobalt(Co)or nickel(Ni)serve as the binder phase,providing toughness and s...Tungsten carbide-based(WC-based)cemented carbides are widely recognized as high-performance tool materials.Traditionally,single metals such as cobalt(Co)or nickel(Ni)serve as the binder phase,providing toughness and structural integrity.Replacing this phase with high-entropy alloys(HEAs)offers a promising approach to enhancing mechanical properties and addressing sustainability challenges.However,the complex multi-element composition of HEAs complicates conventional experimental design,making it difficult to explore the vast compositional space efficiently.Traditional trial-and-error methods are time-consuming,resource-intensive,and often ineffective in identifying optimal compositions.In contrast,artificial intelligence(AI)-driven approaches enable rapid screening and optimization of alloy compositions,significantly improving predictive accuracy and interpretability.Feature selection techniques were employed to identify key alloying elements influencing hardness,toughness,and wear resistance.To enhance model interpretability,explainable artificial intelligence(XAI)techniques—SHapley Additive exPlanations(SHAP)and Local Interpretable Model-agnostic Explanations(LIME)—were applied to quantify the contributions of individual elements and uncover complex elemental interactions.Furthermore,a high-throughput machine learning(ML)–driven screening approach was implemented to optimize the binder phase composition,facilitating the discovery of HEAs with superiormechanical properties.Experimental validation demonstrated strong agreement between model predictions and measured performance,confirming the reliability of the ML framework.This study underscores the potential of integrating ML and XAI for data-driven materials design,providing a novel strategy for optimizing high-entropy cemented carbides.展开更多
We theoretically investigate a one-dimensional Su–Schrieffer–Heeger(SSH)model with spin–orbit coupling(SOC)and sublattice-dependent gain and loss.As the gain and loss increase,the system transitions from a parity-t...We theoretically investigate a one-dimensional Su–Schrieffer–Heeger(SSH)model with spin–orbit coupling(SOC)and sublattice-dependent gain and loss.As the gain and loss increase,the system transitions from a parity-time(PT)symmetric phase to a parity-time and anti-parity-time(PT&APT)symmetry-breaking phase,and finally to an anti-paritytime(APT)symmetric phase.Notably,when the intracell and intercell hopping,intracell and intercell SOC parameters are all equal to half the gain–loss parameter,the model exhibits a doubly degenerate exceptional point(EP).When the SOC is equal for intracell and intercell interactions,a stronger hopping mechanism within cells compared to that between cells results in an increase in SOC that transitions the Zak phase from zero to a non-quantized value,eventually arriving at one.In contrast,a reduction in the strength of intracell hopping leads the Zak phase to transition from two to a non-quantized value,eventually arriving at one.If the intracell and intercell SOC are not aligned,altering these couplings leads to a shift in the Zak phase from two to a non-quantized level,then to one,re-entering the non-quantized region,and eventually arriving at zero.We suggest a practical experimental setup for our model that can be implemented using electrical circuits.展开更多
Covalent organic frameworks(COFs)have demonstrated great potential in chromatographic separation because of unique structure and superior performance.Herein,single-crystal three-dimensional(3D)COFs with regular morpho...Covalent organic frameworks(COFs)have demonstrated great potential in chromatographic separation because of unique structure and superior performance.Herein,single-crystal three-dimensional(3D)COFs with regular morphology,good monodispersity and high specific surface area,were used as a stationary phase for high-performance liquid chromatography(HPLC).The single-crystal 3D COFs packed column not only exhibits high efficiency in separating hydrophobic molecules involving substituted benzenes,halogenated benzenes,halogenated nitrobenzenes,aromatic amines,aromatic hydrocarbons(PAHs)and phthalate esters(PAEs),but also achieves baseline separation of acenaphthene and acenaphthylene with similar physical and chemical properties as well as environmental pollutants,which cannot be quickly separated on commercial C18 column and a polycrystalline 3D COFs packed column.Especially,the column efficiency of 17303-24255 plates/m was obtained for PAEs,and the resolution values for acenaphthene and acenaphthylene,and carbamazepine(CBZ)and carbamazepine-10,11-epoxide(CBZEP)were 1.7and 2.2,respectively.This successful application not only confirmed the great potential of the singlecrystal 3D COFs in HPLC separation of the organic molecules,but also facilitates the application of COFs in separation science.展开更多
Shape memory alloys(SMAs)are well-suited for vibration and noise reduction due to their outstanding mechanical and damping properties.However,their damping capacity is limited due to low-temperature stabilized thermoe...Shape memory alloys(SMAs)are well-suited for vibration and noise reduction due to their outstanding mechanical and damping properties.However,their damping capacity is limited due to low-temperature stabilized thermoelastic martensite and constrained twin migration.This work designs nanoscale Nb phases to enhance the damping capacity and maintain a wide working temperature range of NiTiHf-based SMAs.The NiTiHf/Nb alloys containing spherical Nb phases demonstrate a 125%improvement in internal friction(IF)and remain stable up to 400 K.Alloys with spherical Nb phases exhibit relatively high intrinsic IF,which is mainly attibuted to the high migration ability of martensitic twin boundaries.High-resolution transmission electron microscopy images and IF spectra suggest spherical Nb phases pro-vide additional dislocation damping effects and interface damping effects by inducing multiple types of dislocations near the multi-directional phase interfaces.These findings provide insights into the role of second-phase shape effect in damping properties and offer valuable guidance for designing ultra-high damping alloys.展开更多
基金supported by the National Natural Science Foundation of China(No.22276219)the foundation for Innovative Research Groups of the National Natural Science Foundation of China(No.52121004)+1 种基金the major program Natural Science Foundation of Hunan Province of China(No.2021JC0001)the Fundamental Research Funds for the Central Universities of Central South University(No.2024ZZTS0063).
文摘Beryllium-containing sludge(BCS)is a typical hazardous waste from Be smelting,which can cause serious harm to ecology and human health by releasing harmful Be if it is stored long-term in environment.Nonetheless,the occurrence of Be in BCS is unclear,which seriously hinders the development of pollution control technologies.In order to enhance the understanding of BCS,the occurrence of Be and the microscale interactions with coexisting phases were investigated for the first time.It was found that CaSO_(4)·2H_(2)O and amorphous SiO_(2) are the primary phases of BCS.The simulated experiments of purified materials showed that Be interacted with CaSO_(4)·2H_(2)O and amorphous SiO_(2).Be can enter into the lattice of CaSO_(4)·2H_(2)O mainly as free Be2+.Amorphous SiO_(2) can adsorb Be2+particularly at a pH range of 3–5.The dissolution behavior experiment of BCS shows that about 52%of the Be is readily extracted under acidic conditions,which refers to the Be of independent occurrence.In contrast,the remaining 48%of Be can be extracted only after the CaSO_(4)·2H_(2)O has completely dissolved.Hence,CaSO_(4)·2H_(2)O is identified as the key occurrence phase which determines the highly efficient dissolution of Be.As a result,this study enhances the understanding of BCS and lays the foundation for the development of Be separation technologies.
文摘Objective:To evaluate the effectiveness of surgical combination with traditional Chinese medicine dialectical therapy in three phases for the treatment of intertrochanteric fracture of the femur(IFF).Methods:84 patients with IFF admitted to the hospital from December 2022 to December 2024 were selected and randomly divided into two groups using a random number table.The combined group received surgery and traditional Chinese medicine dialectical therapy in three phases,while the control group received surgery alone.The total effective rate,fracture healing time,hip function score,and lower extremity function score were compared between the two groups.Results:The total effective rate was higher in the combined group than in the control group(P<0.05).After treatment,the fracture healing time was shorter in the combined group than in the control group,and the hip function and lower extremity function scores were higher in the combined group than in the control group(P<0.05).Conclusion:Surgical combination with traditional Chinese medicine dialectical therapy in three phases can shorten the fracture healing time of IFF patients and restore their hip and lower extremity function,demonstrating significant efficacy.
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National Natural Science Foundation of China(Nos.52301041,52022017,52065009,52371005)Special Fund for Special Posts of Guizhou University,China(No.[2023]26)+1 种基金Science and Technology Planning Project of Guizhou Province,China(No.ZK2021269)Fundamental Research Funds for the Central Universities,China(No.DUT23YG104)。
文摘Microstructural characterization,mass loss tests,hydrogen evolution tests,electrochemical measurements,and corrosion morphology observations were conducted to investigate the effect of the secondary phases on the corrosion behavior of the as-cast Mg−7Sn−1Zn−1Y(TZW711)alloy after solution treatment(T4)and aging treatment(T6).The results show that the T4-TZW711 alloy possesses the highest corrosion resistance in the early corrosion stage.This is because the dissolution of Mg2Sn reduces the cathodic current density and increases the charge transfer resistance(Rct).When the corrosion time is prolonged,the undissolved and clustered MgSnY phase will peel off from the T4-TZW711 alloy surface,thereby increasing the corrosion rate of the alloy.After aging treatment,the undissolved MgSnY phase is dispersed,which results in a lower localized corrosion sensitivity of T6-TZW711 alloy than that of the T4-TZW711 alloy,suggesting that the T6 treatment can enhance the corrosion resistance of Mg−7Sn−1Zn−1Y alloys.
基金supported by the U.S.Department of Energy’s Office of Energy Efficiency and Renewable Energy(EERE)under the Advanced Manufacturing Office Award Number DE-EE0007897。
文摘In secondary Al-Si based alloys,microalloying with Mn and Cr can modify harmful platelet-type Alx Fey Siz intermetallic phases to less detrimentalα-Alx(Fe,Mn,Cr)_(y)Siz phase(script or polygonal morphologies).However,theα-Alx(Fe,Mn,Cr)_(y)Siz phase morphology,phase composition and the addition of Fecorrecting elements can be influenced by solidification conditions.Therefore,this research is aimed to highlight the morphological evolution and mechanisms ofα-Alx(Fe,Mn,Cr)_(y)Si_(z)phase in a Cr added Al-9%Si-1%Fe-0.2%Cr(all weight percentage thereafter,unless otherwise stated)alloy with varying Mn concentrations(0.25%,0.5%,and 0.8%).Microstructure evolution of Fe intermetallic phases is investi-gated under different casting conditions using a wedge-shaped die,Cu-chill block and melt quenching experiments.Thermodynamic simulations have been performed using CALculation of PHAse Diagrams(CALPHAD)method and compared with the experimental results for phase composition and formation temperatures ofα-Alx(Fe,Mn,Cr)_(y)Siz phase.The results indicated that for 0.25Mn-0.2Cr addition to Al-9Si-1Fe alloy,compact morphology containing polygonal phases are formed in Cu-chill casting,while the wedge castings predominantly show a mixed structure with platelets and script type morphologies.Tensile tests revealed a higher elongation value of 6.6%for mixed structure with platelet and script phases,which is decreased to 4.2%for polygonal phases in Al-9Si-1Fe-0.2Cr-0.25Mn alloy.This study highlights the importance of solidification conditions on morphologies of Fe-intermetallic phases and the mechanical properties by comparing selected literature relevant to high pressure die-casting process.
基金supported by the National Natural Science Foundation of China(Nos.52201119,52371108,52203295)the Joint Fund of Henan Science and Technology R&D Plan of China(242103810056)Frontier Exploration Project of Longmen Laboratory,China(LMQYTSKT014).
文摘In this study,friction stir processing(FSP)was employed to modify the as-cast Mg-14Gd-0.6Ce-0.5Zr alloy,and the effects of texture evolution and distribution of second phases on mechanical properties were systematically investigated.The results show that friction stir processing effectively refined the coarse Mg_(5)Gd phases into nanoscale second phases uniformly distributed along grain boundaries.The synergistic effect of texture weakening and second phases refinement significantly enhanced the tensile strength and elongation of the FSP-1000-120 alloy to 302.1 MPa and 18.3%,respectively,representing increases of 20.8%and 281.3%compared to the as-cast alloy.The as-cast alloy has a lower corrosion rate in the initial stage due to fewer micro-galvanic corrosion sites.However,the uniform distribution of the second phase in the FSP-treated(FSPed)alloy contributes to the formation of a more complete and dense corrosion product film.After 120 h of immersion,the as-cast alloy forms deep pits due to the continuous dissolution at the second phase-matrix interface,with the average corrosion rate increasing from 0.31 to 0.47 mL/cm^(2)/h.The long-term corrosion rates of FSP-1000-60,FSP-1000-120,and FSP-1200-120 samples are stable at 0.36,0.43,and 0.50 mL/cm^(2)/h,respectively.Research reveals that FSP regulates texture and second phase distribution to achieve synergistic strengthening of alloy strength plasticity,and the homogenization of second phase distribution is a key factor in improving the long-term corrosion resistance of alloys.
文摘The precipitation of secondary Laves phases and its effect on notch sensitivity are systematically studied in Thermo-Span alloy. The results show that the precipitation peak temperature of secondary Laves phases is 925 ℃. Below 925 ℃, the volume fraction of secondary Laves phases increases with the rise of the temperature, and its morphology changes from granular to thin-film;above 925 ℃, the volume fraction of secondary Laves phases shows an opposite trend to temperature, and its morphology changes from thin-film to granular. A detailed explanation through linear density (ρ) is provided that the influence of secondary Laves phases at the grain boundaries (GBs) on notch sensitivity depends on the coupling competition effect of their size, quantity, and morphology. Notably, the granular Laves phases are more beneficial to improving the notch sensitivity of the alloy compared with thin-film Laves phases. Granular secondary Laves phases can promote the formation of γ′ phases depletion zone to improve the ability of GBs to accommodate high strain localization, and effectively inhibit the crack initiation and propagation.
基金supported by the National Natural Science Foundation of China(Nos.52371106,52371025,52171154,51871076,52071118,and 52301223)Interdisciplinary Research Foundation of HIT(No.IR2021201)+4 种基金the Natural Science Foundation of Ningbo City(No.2023J346)supported by Zhejiang Provincial Natural Science Foundation of China(No.LQ24E010004)supported by the National Science Foundation(NSF)-Earth Sciences(No.EAR-1634415)the Department of Energy(DOE)-GeoSciences(No.DE-FG02-94ER14466)supported by DOE-BES(No.DE-AC02-06CH11357).
文摘1.Introduction Compared with the widely used vapor-compression refrigeration,solid-state cooling based on phase transition offers higher ef-ficiency,environmental friendliness,and smaller volume[1,2].The phase transition of solid refrigerants can be triggered by external fields,i.e.,magnetic fields[3-5],electric fields[6,7].
基金supported by the Science and technology development project of Transport Planning and Research Institute of Ministry of Transport of China(No.092517-905).
文摘Rapid urbanization reshapes landscape patterns and intensifies stormwater runoff pressure,yet the shifting cost-effectiveness of green infrastructure across different urban development phases remains poorly quantified.Focusing on Beijing’s 150 km2 urban subcenter,this study quantified 21 block-level landscape metrics,which were distilled via principal component analysis into five landform indicators:dominance,fragmentation,edge,aggregation,and shape.K-means clustering classified each block into constructed,constructing,or unconstructed phases.A life-cycle cost analysis then estimated the bioretention investment required to meet an 80%-85%annual runoff volume control target.The constructing phase,characterized by contiguous impervious surfaces at the urban edge,demands 45%more bioretention investment per unit area than the unconstructed phase and 4%more than the constructed phase.As land transitions from unconstructed to constructed,bioretention costs increase by approximately 109%for agricultural land and 86%for green space,whereas changes for residential and commercial areas remain minimal.These results indicate that uniform runoff control investment policies risk underfunding rapidly developing fringes and overfunding consolidated urban centers.A phase-specific and land use-sensitive investment strategy is therefore necessary to avoid capital inefficiency while achieving runoff control goals.By linking dynamic landscape evolution with infrastructure economics,this study provides a forward-looking tool to guide runoff control investment during urban expansion.
文摘In the energy industry landscape,thermal power generation stands as a critical energy supply method,and the safety of its construction and operation is paramount.Currently,all stages of the life cycle of construction projects have garnered widespread attention.Among these,the infrastructure construction and operation phases of thermal power generation enterprises pose numerous issues worthy of in-depth study in terms of safety production management.This article starts by examining safety production management during these two phases,analyzing characteristics such as management models,legal bases,and responsible entities.It explores the reasons behind these characteristics and elaborates on key management priorities,providing a comprehensive and insightful reference for safety production management in thermal power generation enterprises.
基金Project supported by the National Natural Science Foundation of China(52374330,52325406)。
文摘The addition of Ce significantly enhances cleanliness of steel and modifies precipitation phases.However,there are differences in the effects of different alloy systems,especially its role in M54 steel is insufficiently understood.This study investigates the evolution of inclusions and precipitation phases in M54 steel ingots with varying Ce additions.Results indicate that the addition of Ce reduces the content of impurity elements(O and S)and transforms Mg and Al inclusions into Ce inclusions,which is due to the stronger affinity between Ce and impurity elements such as O and S.Ce inclusions serve as nucleation sites for dendrites,reducing secondary dendrite arm spacing.In addition,these inclusions and Cecontaining precipitated phase also act as nucleation sites for carbide precipitates,effectively refining their distribution by reducing growth spaces and increasing nucleation density.Notably,as Ce content increases from 0 to 0.01 wt%,the precipitation phase content decreases significantly but rises slightly with further increases in Ce content due to the formation of additional Ce-containing precipitates.By quantitatively comparing the dendrite arm spacing,cleanliness,content and size of precipitated phase,it is determined that the optimum addition amount of Ce for M54 steel is about 0.01 wt%.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11904309 and 12305015)the Natural Science Foundation of Hunan Province,China(Grant No.2020JJ5528)the Natural Science Foundation of Hebei Province,China(Grant No.A2024205027)。
文摘Machine learning has rapidly become a powerful tool for addressing challenges in ultracold atomic systems;however,its application to intricate three-dimensional(3D)systems remains relatively underexplored.In this study,we introduce a3D residual network(3D Res Net)framework based on 3D convolutional neural networks(3D CNN)to predict ground states phases in 3D dipolar spinor Bose–Einstein condensates(BECs).Our results show that the 3D Res Net framework predicts ground states with high accuracy and efficiency across a broad parameter space.To enhance phase transition predictions,we incorporate data augmentation techniques,leading to a notable improvement in the model's performance.The method is further validated in more complex scenarios,particularly when transverse magnetic fields are introduced.Compared to conventional imaginary-time evolution methods(ITEM),the 3D Res Net drastically reduces computational costs,offering a rapid and scalable solution for complex 3D multi-parameter nonlinear systems.
基金supported by the National Natural Science Foundation of China(Nos.22174067,22204078,22374077,and 22474059)the Natural Science Foundation of Jiangsu Province of China(No.BK20220370)+2 种基金Jiangsu Provincial Department of Education(No.22KJB150009)Jiangsu Association for Science and Technology(No.TJ-2023-076)the Priority Academic Program Development of Jiangsu Higher Education Institutions。
文摘For chromatographic separation,the reasonable modulation of stationary phases is the key factor to achieve high separation performance.We proposed that developing MOF stationary phases through precisely modulating the thermodynamic interactions between MOFs and analytes is conducive to improving the separation resolution.MIL-125,MIL-125-NH_(2),MIL-143-BTB,and MIL-143-TATB were developed as stationary phases with the careful modulation of organic ligands.MIL-125-NH_(2)and MIL-143-TATB coated columns exhibited much better separation performance than their counterparts,MIL-125 and MIL-143-BTB,respectively.The investigation of the separation mechanism indicated that thermodynamic interaction,rather than kinetic diffusion,was responsible for the separation improvement.MIL-125-NH_(2)and MIL-143-TATB provided stronger and distinguishable interactions with targets than corresponding MIL-125 and MIL-143-BTB,respectively,resulting in enhanced separation performance.This work demonstrates a guide to improving the separation performance of MOF stationary phases by increasing the thermodynamic interactions between MOFs and analytes.
基金supported by National Natural Science Foundation of China(Nos.52325406 and 52374330)Fundamental Research Funds for the Central Universities(No.N2225046).
文摘A mathematical model coupling flow,solidification,strain-stress,and interface failure was developed.Following identification of crack source type through thermal tensile experiment and validation by strain-stress comparison,the model was used to investigate slab cracking tendency near precipitated phases,considering various locations,sizes and shapes of them.The results show that the jet from submerged entry nozzle creates a“double roll”flow pattern during continuous casting,resulting in more uniform temperature distributions at slab corner and wide surface center compared with narrow surface center.Consequently,precipitated phases,particularly those located on the narrow surface,readily induce stress concentration and thus increase cracking tendency.A smaller precipitated phase size can reduce the stress concentration zone,while a more spherical shape can distribute surrounding stress along its surface and lower the internal stress within it,thereby decreasing the risk of slab cracking during continuous casting.The optimal precipitated phase exhibits a spherical or ellipsoidal shape with a major axis of less than 5µm,minimizing its potential to initiate cracks.
文摘Tungsten carbide-based(WC-based)cemented carbides are widely recognized as high-performance tool materials.Traditionally,single metals such as cobalt(Co)or nickel(Ni)serve as the binder phase,providing toughness and structural integrity.Replacing this phase with high-entropy alloys(HEAs)offers a promising approach to enhancing mechanical properties and addressing sustainability challenges.However,the complex multi-element composition of HEAs complicates conventional experimental design,making it difficult to explore the vast compositional space efficiently.Traditional trial-and-error methods are time-consuming,resource-intensive,and often ineffective in identifying optimal compositions.In contrast,artificial intelligence(AI)-driven approaches enable rapid screening and optimization of alloy compositions,significantly improving predictive accuracy and interpretability.Feature selection techniques were employed to identify key alloying elements influencing hardness,toughness,and wear resistance.To enhance model interpretability,explainable artificial intelligence(XAI)techniques—SHapley Additive exPlanations(SHAP)and Local Interpretable Model-agnostic Explanations(LIME)—were applied to quantify the contributions of individual elements and uncover complex elemental interactions.Furthermore,a high-throughput machine learning(ML)–driven screening approach was implemented to optimize the binder phase composition,facilitating the discovery of HEAs with superiormechanical properties.Experimental validation demonstrated strong agreement between model predictions and measured performance,confirming the reliability of the ML framework.This study underscores the potential of integrating ML and XAI for data-driven materials design,providing a novel strategy for optimizing high-entropy cemented carbides.
基金Project supported by the Natural Science Foundation of Chongqing,China(Grant No.CSTB2024NSCQ-MSX0736)Science and Technology Innovation Key R&D Program of Chongqing(Grant No.CSTB2024TIAD-STX0035)the Research Foundation of Institute for Advanced Sciences of CQUPT(Grant No.E011A2022328)。
文摘We theoretically investigate a one-dimensional Su–Schrieffer–Heeger(SSH)model with spin–orbit coupling(SOC)and sublattice-dependent gain and loss.As the gain and loss increase,the system transitions from a parity-time(PT)symmetric phase to a parity-time and anti-parity-time(PT&APT)symmetry-breaking phase,and finally to an anti-paritytime(APT)symmetric phase.Notably,when the intracell and intercell hopping,intracell and intercell SOC parameters are all equal to half the gain–loss parameter,the model exhibits a doubly degenerate exceptional point(EP).When the SOC is equal for intracell and intercell interactions,a stronger hopping mechanism within cells compared to that between cells results in an increase in SOC that transitions the Zak phase from zero to a non-quantized value,eventually arriving at one.In contrast,a reduction in the strength of intracell hopping leads the Zak phase to transition from two to a non-quantized value,eventually arriving at one.If the intracell and intercell SOC are not aligned,altering these couplings leads to a shift in the Zak phase from two to a non-quantized level,then to one,re-entering the non-quantized region,and eventually arriving at zero.We suggest a practical experimental setup for our model that can be implemented using electrical circuits.
基金the National Natural Science Foundation of China(No.22274021)Natural Science Foundation of Fujian Province(No.2022J01535)for financial support。
文摘Covalent organic frameworks(COFs)have demonstrated great potential in chromatographic separation because of unique structure and superior performance.Herein,single-crystal three-dimensional(3D)COFs with regular morphology,good monodispersity and high specific surface area,were used as a stationary phase for high-performance liquid chromatography(HPLC).The single-crystal 3D COFs packed column not only exhibits high efficiency in separating hydrophobic molecules involving substituted benzenes,halogenated benzenes,halogenated nitrobenzenes,aromatic amines,aromatic hydrocarbons(PAHs)and phthalate esters(PAEs),but also achieves baseline separation of acenaphthene and acenaphthylene with similar physical and chemical properties as well as environmental pollutants,which cannot be quickly separated on commercial C18 column and a polycrystalline 3D COFs packed column.Especially,the column efficiency of 17303-24255 plates/m was obtained for PAEs,and the resolution values for acenaphthene and acenaphthylene,and carbamazepine(CBZ)and carbamazepine-10,11-epoxide(CBZEP)were 1.7and 2.2,respectively.This successful application not only confirmed the great potential of the singlecrystal 3D COFs in HPLC separation of the organic molecules,but also facilitates the application of COFs in separation science.
基金supported by the National Natural Science Foundation of China(Grant No.52471160).
文摘Shape memory alloys(SMAs)are well-suited for vibration and noise reduction due to their outstanding mechanical and damping properties.However,their damping capacity is limited due to low-temperature stabilized thermoelastic martensite and constrained twin migration.This work designs nanoscale Nb phases to enhance the damping capacity and maintain a wide working temperature range of NiTiHf-based SMAs.The NiTiHf/Nb alloys containing spherical Nb phases demonstrate a 125%improvement in internal friction(IF)and remain stable up to 400 K.Alloys with spherical Nb phases exhibit relatively high intrinsic IF,which is mainly attibuted to the high migration ability of martensitic twin boundaries.High-resolution transmission electron microscopy images and IF spectra suggest spherical Nb phases pro-vide additional dislocation damping effects and interface damping effects by inducing multiple types of dislocations near the multi-directional phase interfaces.These findings provide insights into the role of second-phase shape effect in damping properties and offer valuable guidance for designing ultra-high damping alloys.
