The service life of refractory brick in the slag tapping hole of gasifiers is a significant concern for long-term and stable operation.This study examined the damage mechanism of high chromia refractory of four commer...The service life of refractory brick in the slag tapping hole of gasifiers is a significant concern for long-term and stable operation.This study examined the damage mechanism of high chromia refractory of four commercial coal-water slurry gasifiers with their corresponding gasification coal samples and the corroded refractory bricks in the slag tapping hole of the gasifier.The slag characteristic,including crystallization and viscosity-temperature of four gasification coal samples were analyzed.The results revealed that the low viscosity slag could lead to more severe damage to refractory bricks.Given the risk of slag crystallization,it is recommended to establish a safe slag tapping temperature range should be set as tICT(initial crystallization temperature)−t_(2.5) when tICT is higher than t_(25).Upon examining interior morphology of these corroded refractory bricks,some cracks were observed within them.The chemical composition of molten slag was analyzed using SEM-EDS.However,XRD results found no spinel containing zirconium in these cracks.This suggests that the emergence of these cracks are mainly attributed to the molten slag penetration and the subsequent reaction with the refractory material.The difference in thermal expansion between the newly formed substances and refractory material is critical in forming these cracks.Furthermore,SEM-EDS analysis was also conducted on the slag-aggregate and the slag-matrix interface.The results reveal that the reduction in Cr_(2)O_(3) content is the earliest characteristic of damage in high chromia refractories.A proposed damage mechanism of refractory brick suggests that the matrix and aggregate of high chromia refractory are initially compromised because of the reduced Cr_(2)O_(3) content.Subsequently,the molten slag penetrates the interior of the refractory brick,forming new substances,leading to damage caused by the difference in thermal expansion between the new substances and the refractory brick.Understanding and preventing the reduction of Cr_(2)O_(3) content is vital to prolonging the service life of refractory brick in the slag tapping hole of the gasifier based on this damage mechanism.展开更多
The effect of element Ti on the microstructures and mechanical properties of as-cast and annealed NbTaMoWTi,(x=0,1,1.5,2)refractory high-entropy alloys(RHEAs)was investigated.Results show that after Ti addition,the as...The effect of element Ti on the microstructures and mechanical properties of as-cast and annealed NbTaMoWTi,(x=0,1,1.5,2)refractory high-entropy alloys(RHEAs)was investigated.Results show that after Ti addition,the as-cast alloys maintain their original single body-centered cubic(bcc)structure.As for the mechanical properties,compared with those without Ti addition,the strength and ductility of NbTaMoWTi,alloys increase by 93%and 215%,respectively.Furthermore,the NbTaMoWTi alloys exhibit outstanding thermal stability.After annealing at 1400 C,they still maintain the single bcc structure,and their mechanical properties are even slightly improved.However,annealing leads to a significant deterioration in the mechanical properties of high-Ti-content alloys(NbTaMoWTil and NbTaMoWTi2),owing to the formation of Ti-rich acicular phases.展开更多
Refractory metals,including tungsten(W),tantalum(Ta),molybdenum(Mo),and niobium(Nb),play a vital role in industries,such as nuclear energy and aerospace,owing to their exceptional melting temperatures,thermal durabili...Refractory metals,including tungsten(W),tantalum(Ta),molybdenum(Mo),and niobium(Nb),play a vital role in industries,such as nuclear energy and aerospace,owing to their exceptional melting temperatures,thermal durability,and corrosion resistance.These metals have body-centered cubic crystal structure,characterized by limited slip systems and impeded dislocation motion,resulting in significant low-temperature brittleness,which poses challenges for the conventional processing.Additive manufacturing technique provides an innovative approach,enabling the production of intricate parts without molds,which significantly improves the efficiency of material usage.This review provides a comprehensive overview of the advancements in additive manufacturing techniques for the production of refractory metals,such as W,Ta,Mo,and Nb,particularly the laser powder bed fusion.In this review,the influence mechanisms of key process parameters(laser power,scan strategy,and powder characteristics)on the evolution of material microstructure,the formation of metallurgical defects,and mechanical properties were discussed.Generally,optimizing powder characteristics,such as sphericity,implementing substrate preheating,and formulating alloying strategies can significantly improve the densification and crack resistance of manufactured parts.Meanwhile,strictly controlling the oxygen impurity content and optimizing the energy density input are also the key factors to achieve the simultaneous improvement in strength and ductility of refractory metals.Although additive manufacturing technique provides an innovative solution for processing refractory metals,critical issues,such as residual stress control,microstructure and performance anisotropy,and process stability,still need to be addressed.This review not only provides a theoretical basis for the additive manufacturing of high-performance refractory metals,but also proposes forward-looking directions for their industrial application.展开更多
Intelligent refractory materials represent a new generation of high-temperature functional materials that significantly enhance the service performance of traditional refractories in extreme environments through integ...Intelligent refractory materials represent a new generation of high-temperature functional materials that significantly enhance the service performance of traditional refractories in extreme environments through integrated sensing,response,and adaptive mechanisms.A comprehensive overview of intelligent refractory materials was provided,focusing on their classification,preparation techniques,and industrial applications.Firstly,the categories and design principles of intelligent refractory materials are introduced,including self-healing,self-regulating,and self-diagnosing types,which enhance durability and performance under extreme conditions.Subsequently,advanced preparation technologies are discussed,such as 3D printing for complex geometries,nanocomposite engineering for improved mechanical and thermal properties,gradient design for optimized thermal stress resistance and information technology including machine learning,health monitoring,digital twin.Finally,the industrial applications of these materials are highlighted,particularly in steel metallurgy,building materials industry,and energy.It aims to bridge the gap between research advancements and practical implementation,offering insights into future trends in intelligent refractory material development.展开更多
Fenton-like technology based on peroxymonosulfate activation has shown great potential in refractory organics degradation.In this work,single Fe atom catalysts were synthesized through facile ball milling and exhibite...Fenton-like technology based on peroxymonosulfate activation has shown great potential in refractory organics degradation.In this work,single Fe atom catalysts were synthesized through facile ball milling and exhibited very high performance in peroxymonosulfate activation.The Fe single-atom filled an N vacancy on the triazine ring edge of C_(3)N_(4),as confirmed through X-ray absorption fine structure,density functional calculation and elec-tron paramagnetic resonance.The SAFe_(0.4)–C_(3)N_(4)/PMS system could completely remove phenol(20 mg/L)within 10 min and its first-order kinetic constant was 12.3 times that of the Fe_(3)O_(4)/PMS system.Under different ini-tial pH levels and in various anionic environments,SAFe_(0.4)–C_(3)N_(4) still demonstrated excellent catalytic activity,achieving a removal rate of over 90%for phenol within 12 min.In addition,SAFe_(0.4)–C_(3)N_(4) exhibited outstanding selectivity in reaction systems with different pollutants,showing excellent degradation effects on electron-rich pollutants only.Hydroxyl radicals(•OH),singlet oxygen(1O_(2))and high-valent iron oxide(Fe(Ⅳ)=O)were de-tected in the SAFe_(0.4)–C_(3)N_(4)/PMS system through free radical capture experiments.Further experiments on the quenching of active species and a methyl phenyl sulfoxide probe confirmed that 1O_(2) and Fe(Ⅳ)=O played dom-inant roles.Additionally,the change in the current response after adding PMS and phenol in succession proved that a direct electron transfer path between organic matter and the catalyst surface was unlikely to exist in the SAFe_(0.4)–C_(3)N_(4)/PMS/Phenol degradation system.This study provides a new demonstration of the catalytic mech-anism of single-atom catalysts.展开更多
High temperature industries are a critical focus for energy conservation and carbon reduction.As fundamental materials for these industries,refractories urgently require the development of high-performance,low thermal...High temperature industries are a critical focus for energy conservation and carbon reduction.As fundamental materials for these industries,refractories urgently require the development of high-performance,low thermal conductivity,and long service life materials to support green and low carbon development.To achieve refractories with both low thermal conductivity and excellent service performance,porous anorthite-spinel refractories were developed via in-situ decomposition pore-forming technology.The effects of spinel on microstructure evolution,strength,and thermal conductivity were investigated,supplemented by thermodynamic calculations.The results indicated that the porous anorthite-spinel refractory primarily consisted of anorthite and spinel,with minor corundum.Small-sized spinel particles were uniformly dispersed in the matrix,while the spinel reaction layers forming on the surfaces of large-sized crushed powder particles,wrapping around the remaining unreacted particles.The improvement of the degree of direct bonding between anorthite and spinel in the matrix and the small amount of diffusely distributed in situ spinel forced the deflection of the crack extension paths,which was conducive to the enhancement of the compressive strength of porous anorthite-spinel refractory.The optimized composition had 20 wt.%spinel and its apparent porosity and cold compressive strength were 43.6%and 37.8 MPa.Compared to porous anorthite refractories,the porous anorthite-spinel refractories exhibited a 21%reduction in thermal conductivity(500℃),and a 12%improvement in cold compressive strength.Valuable insights for the resource utilization of corundum dust and the design of energy efficient refractory insulation layers in high temperature industries are provided by this study.展开更多
The deformation characteristics and activation mechanisms of kink bands in refractory multi-principal element alloys with local chemical fluctuations(LCFs)were systematically studied.These alloys were fabricated using...The deformation characteristics and activation mechanisms of kink bands in refractory multi-principal element alloys with local chemical fluctuations(LCFs)were systematically studied.These alloys were fabricated using laser-directed energy deposition technology and characterized by room-temperature compression testing,electron backscatter diffraction(EBSD),transmission electron microscopy(TEM),and high-angle annular dark-field(HAADF)imaging.The results reveal that kinking is a gradual rotational diffusion process,during which the misorientation difference between the kink and the matrix varies.A low Schmid factor is a prerequisite for kink excitation.The slip system closest to the loading axis is passively activated by the applied external force,leading to the accumulation of geometrically necessary dislocations(GNDs)required for lattice rotation.The widespread LCFs within the matrix reduce the migration rate of edge dislocations,promoting GND accumulation and enhancing the propensity for kink band formation.During deformation,the occurrence of kinking enables continuous lattice rotation to accommodate the exceptionally high strain in the vicinity,when the stress concentration in the primary kink cannot be fully released,double kinks are activated to reduce strain energy.展开更多
Exploiting effective approaches to achieve superior ductility has consistently been a topic of widespread interest in refractory multi-principal-element alloys(RMPEAs).Herein,we developed a one-step forming method,ele...Exploiting effective approaches to achieve superior ductility has consistently been a topic of widespread interest in refractory multi-principal-element alloys(RMPEAs).Herein,we developed a one-step forming method,electron-beam directional-solidification(EB-DS),to fabricate an equiatomic Hf-Nb-Ta-Zr RMPEA,and compared its microstructures as well as mechanical properties with those of the as-cast alloy fabricated by levitation induction melting.EB-DS method can transform the equiaxed grain microstructures in the as-cast alloy to columnar grain microstructures as well as eliminate the slight segregation.The room-temperature tensile test demonstrates that the ductility is substantially improved from 3.9%for the as-cast alloy to 23%for EB-DS alloy,accompanied by the slight enhancement in yield strength from 946 to 991 MPa.The microstructural investigations indicate that EB-DS alloys with columnar grains present a significantly optimized coordinated plastic deformation between the grain boundary region and the grain interior region,leading to the suppression of cracking along grain boundaries.展开更多
Microwave roasting self-leaching is an innovative method for recovering gold from high-sulfur refractory gold concentrates,without using deadly toxic cyanide reagents.However,the mechanism of gold self-leaching,which ...Microwave roasting self-leaching is an innovative method for recovering gold from high-sulfur refractory gold concentrates,without using deadly toxic cyanide reagents.However,the mechanism of gold self-leaching,which relies on lixiviants prepared using volatilized sulfur obtained from roasting,has not been fully elucidated.This study employs the response surface methodology to optimize processing parameters,resulting in an increased gold extraction rate of 96.18%.Analytical factorization and the Tafel curve indicate that CuSO_(4) and NH_(3)·H_(2)O significantly influence the self-leaching process.Furthermore,X-ray photoelectron spectroscopy(XPS)analysis reveals that S^(2−),S_(2)^(2−),polysulfides(S_(n)^(2−)),and thiosulfate(S_(2)O_(3)^(2−))are involved in the gold leaching reaction,with S^(2−),S_(2)^(2−),and S_(n)^(2−) serving as primary ligands for gold complexation.The role of S_(2)O_(3)^(2−) in the early stages of the gold-leaching reaction is also noteworthy.The copper–ammonia complex catalyzes the self-leaching gold reaction;however,an improper addition ratio can lead to copper-sulfur compound precipitates,reducing the extraction rate.展开更多
The effects of ZrO_(2)-based refractory materials on non-metallic inclusions in nickel-based superalloy K4169 were systematically investigated.Analytical methods,including X-ray fluorescence,X-ray diffraction,scanning...The effects of ZrO_(2)-based refractory materials on non-metallic inclusions in nickel-based superalloy K4169 were systematically investigated.Analytical methods,including X-ray fluorescence,X-ray diffraction,scanning electron microscopy equipped with energy dispersive spectrometry,and FactSage simulations,revealed that the refractory primarily consisted of ZrO_(2),MgO,MgO·Al_(2)O_(3),and Zr_(1.74)Y_(0.26)O_(3.87) phases.During melting,MgO reacted with[Al]and[O]in the alloy,forming MgO·Al_(2)O_(3) at the interface.This phase adhered to the superalloy,while ZrO_(2) phases remained stable.The inclusions in the alloy transformed from Al_(2)O_(3) to MgO·Al_(2)O_(3),with variations in size and distribution influenced by location and pressure.FactSage kinetic simulations aligned with experimental findings,elucidating the interaction mechanisms between the alloy and refractory.These results provide insights into optimizing refractory materials for improved cleanliness and performance in nickel-based superalloy production.展开更多
1 Production and Running Status of China’s Refractories Industry in 20241.1 Production and Running Status In 2024,according to the statistical data from The Association of China Refractories Industry,China’s refract...1 Production and Running Status of China’s Refractories Industry in 20241.1 Production and Running Status In 2024,according to the statistical data from The Association of China Refractories Industry,China’s refractories output was 22.0711million tons,decreasing by 3.73%YOY;in which the outputs of dense shaped refractory products,insulating refractory products and monolithic refractories were 11.3163 million tons decreasing by 6.07%YOY,83.77 thousand tons increasing by 11.17%YOY,and 9.9971 million tons decreasing by 2.07%YOY,respectively.The outputs of the main varieties are shown in Fig.1.展开更多
Dear Editor,I diopathic macular telangiectasia(MacTel)type 1 is a retinal vascular disease characterized by abnormal dilation of macular capillaries,leading to metamorphopsia,progressive vision loss,and temporal scoto...Dear Editor,I diopathic macular telangiectasia(MacTel)type 1 is a retinal vascular disease characterized by abnormal dilation of macular capillaries,leading to metamorphopsia,progressive vision loss,and temporal scotoma enlargement.Currently,there is no standardized treatment protocol for MacTel type 1[1-2].Treatment outcomes can vary significantly among individuals,highlighting the ongoing need for further exploration of new and more effective treatment options.This paper presents a case of refractory macular edema associated with MacTel type 1,which showed a favorable response to pars plana vitrectomy(PPV)and internal limiting membrane(ILM)peeling.展开更多
Refractory wounds cause significant harm to the health of patients and the most common treatments in clinical practice are surgical debridement and wound dressings.However,certain challenges,including surgical difficu...Refractory wounds cause significant harm to the health of patients and the most common treatments in clinical practice are surgical debridement and wound dressings.However,certain challenges,including surgical difficulty,lengthy recovery times,and a high recurrence rate persist.Conductive hydrogel dressings with combined monitoring and therapeutic properties have strong advantages in promoting wound healing due to the stimulation of endogenous current on wounds and are the focus of recent advancements.Therefore,this review introduces the mechanism of conductive hydrogel used for wound monitoring and healing,the materials selection of conductive hydrogel dressings used for wound monitoring,focuses on the conductive hydrogel sensor to monitor the output categories of wound status signals,proving invaluable for non-invasive,real-time evaluation of wound condition to encourage wound healing.Notably,the research of artificial intelligence(AI)model based on sensor derived data to predict the wound healing state,AI makes use of this abundant data set to forecast and optimize the trajectory of tissue regeneration and assess the stage of wound healing.Finally,refractory wounds including pressure ulcers,diabetes ulcers and articular wounds,and the corresponding wound monitoring and healing process are discussed in detail.This manuscript supports the growth of clinically linked disciplines and offers motivation to researchers working in the multidisciplinary field of conductive hydrogel dressings.展开更多
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
Up-and-coming high-temperature materials,refractory high entropy alloys,are suffering from lower oxidation resistance,restricting their applications in the aerospace field.In this study,two novel treatments of Al-depo...Up-and-coming high-temperature materials,refractory high entropy alloys,are suffering from lower oxidation resistance,restricting their applications in the aerospace field.In this study,two novel treatments of Al-deposited and remelted were developed to refine the microstructure and enhance the oxidation resistance of refractory high entropy alloy using electron beam freeform fabrication(EBF3).Finer and short-range ordering structures were observed in the remelted sample,whereas the Al-deposited sample showcased the formation of silicide and intermetallic phases.High-temperature cyclic and isothermal oxidation tests at 1000℃ were carried out.The total weight gain after 60 h of cyclic oxidation decreased by 17.49%and 30.46%for the remelted and deposited samples,respectively,compared to the as-cast state.Oxidation kinetics reveal an evident lower mass gain and oxidation rate in the treated samples.A multilayer oxide consisting of TiO_(2)+Al_(2)O_(3)+SiO_(2)+AlNbO_(4) was studied for its excellent oxidation resistance.The oxidation behavior of rutile,corundum and other oxides was analyzed using first principles calculations and chemical defect analysis.Overall,this research,which introduces novel treatments,offers promising insights for enhancing the inherent oxidation resistance of refractory high entropy alloys.展开更多
AIM:To assess the efficacy and safety of ultrasound cycloplasty(UCP)in lowering intraocular pressure(IOP)among Chinese patients suffering from refractory glaucoma.METHODS:In this 12-month retrospective study,28 patien...AIM:To assess the efficacy and safety of ultrasound cycloplasty(UCP)in lowering intraocular pressure(IOP)among Chinese patients suffering from refractory glaucoma.METHODS:In this 12-month retrospective study,28 patients with refractory glaucoma(IOP≥25 mm Hg)were treated with 8-second UCP using either 8 or 10 probe sectors.The principal measure of efficacy was the decrease in IOP at the following intervals after UCP:1d,1,3,6,and 12mo,with each measurement compared to baseline.RESULTS:Mean IOP(in mm Hg)was reduced from 46.8±8.9 to 24.5±3.2,27.0±4.8,29.1±4.6,26.1±4.5,and 28.3±4.8 at 1d,1,3,6,and 12mo postoperatively,respectively.Compared to baseline,IOP reductions at these time points were 45.0%,39.9%,35.3%,41.4%,and 36.7%,respectively.Most patients experienced relief from ocular pain after surgery.No cases of choroidal detachment or hypotony was observed.CONCLUSION:UCP is effective in reducing IOP among Chinese patients with refractory glaucoma and shows a favorable safety profile.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
Diffuse large B-cell lymphoma(DLBCL),the most common subtype of non-Hodgkin’s lymphoma(NHL)worldwide,accounts for 39% and 44% of nodal and extranodal NHL cases in China,respectively1.Standard first-line treatment for...Diffuse large B-cell lymphoma(DLBCL),the most common subtype of non-Hodgkin’s lymphoma(NHL)worldwide,accounts for 39% and 44% of nodal and extranodal NHL cases in China,respectively1.Standard first-line treatment for DLBCL is chemo-immunotherapy with rituximab,cyclophos-phamide,doxorubicin,vincristine,and prednisone,which cures 50%-60% of patients2.展开更多
Advanced structural materials with superb mechanical properties at ultrahigh temperatures are essential for aerospace and power-generation sectors.Refractory multi-principal element alloys(RMPEAs)are promising candida...Advanced structural materials with superb mechanical properties at ultrahigh temperatures are essential for aerospace and power-generation sectors.Refractory multi-principal element alloys(RMPEAs)are promising candidates,but they face challenges such as limited plasticity at room temperatures and insufficient strength at ultrahigh temperatures.In this work,we investigated the mechanical properties and microstructures of RMPEA reinforced with compositional complex carbides and demonstrated that tailoring the carbon content can significantly alter their microstructures and enhance mechanical properties.Specifically,the W_(30)Ta_(30)Mo_(15)Nb_(15)C_(10)alloy achieved an ultrahigh strength of 896 MPa at 1600℃ and a plasticity of∼8%at room temperatures.The strengthening effect arises from multi-principal element mixing and robust dislocation hindering at the phase interfaces between the carbides and the matrix,while the room temperature plasticity is attributed to crack buffering facilitated by the highly saturated solid solution matrix.Our study highlights the potential of compositional complex carbide to enhance the mechanical properties of RMPEAs,offering a promising approach for the development of advanced structural materials for ultrahigh temperature applications.展开更多
Grain boundary engineering plays a significant role in the improvement of strength and plasticity of alloys. However, in refractory high-entropy alloys, the susceptibility of grain boundaries to oxygen presents a bott...Grain boundary engineering plays a significant role in the improvement of strength and plasticity of alloys. However, in refractory high-entropy alloys, the susceptibility of grain boundaries to oxygen presents a bottleneck in achieving high mechanical performance. Creating a large number of clean grain boundaries in refractory high-entropy alloys is a challenge. In this study, an ultrafine-grained (UFG) NbMoTaW alloy with high grain-boundary cohesion was prepared by powder metallurgy, taking advantages of rapid hot-pressing sintering and full-process inert atmosphere protection from powder synthesis to sintering. By oxygen control and an increase in the proportion of grain boundaries, the segregation of oxygen and formation of oxides at grain boundaries were strongly mitigated, thus the intrinsic high cohesion of the interfaces was preserved. Compared to the coarse-grained alloys prepared by arc-melting and those sintered by traditional powder metallurgy methods, the UFG NbMoTaW alloy demonstrated simultaneously increased strength and plasticity at ambient temperature. The highly cohesive grain boundaries not only reduce brittle fractures effectively but also promote intragranular deformation. Consequently, the UFG NbMoTaW alloy achieved a high yield strength even at elevated temperatures, with a remarkable performance of 1117 MPa at 1200 ℃. This work provides a feasible solution for producing refractory high-entropy alloys with low impurity content, refined microstructure, and excellent mechanical performance.展开更多
基金Supported by Carbon Neutrality and Energy System Transformation (CNEST) ProgramScience and Technology Innovation Project of CHN Energy (GJNY-24-26)。
文摘The service life of refractory brick in the slag tapping hole of gasifiers is a significant concern for long-term and stable operation.This study examined the damage mechanism of high chromia refractory of four commercial coal-water slurry gasifiers with their corresponding gasification coal samples and the corroded refractory bricks in the slag tapping hole of the gasifier.The slag characteristic,including crystallization and viscosity-temperature of four gasification coal samples were analyzed.The results revealed that the low viscosity slag could lead to more severe damage to refractory bricks.Given the risk of slag crystallization,it is recommended to establish a safe slag tapping temperature range should be set as tICT(initial crystallization temperature)−t_(2.5) when tICT is higher than t_(25).Upon examining interior morphology of these corroded refractory bricks,some cracks were observed within them.The chemical composition of molten slag was analyzed using SEM-EDS.However,XRD results found no spinel containing zirconium in these cracks.This suggests that the emergence of these cracks are mainly attributed to the molten slag penetration and the subsequent reaction with the refractory material.The difference in thermal expansion between the newly formed substances and refractory material is critical in forming these cracks.Furthermore,SEM-EDS analysis was also conducted on the slag-aggregate and the slag-matrix interface.The results reveal that the reduction in Cr_(2)O_(3) content is the earliest characteristic of damage in high chromia refractories.A proposed damage mechanism of refractory brick suggests that the matrix and aggregate of high chromia refractory are initially compromised because of the reduced Cr_(2)O_(3) content.Subsequently,the molten slag penetrates the interior of the refractory brick,forming new substances,leading to damage caused by the difference in thermal expansion between the new substances and the refractory brick.Understanding and preventing the reduction of Cr_(2)O_(3) content is vital to prolonging the service life of refractory brick in the slag tapping hole of the gasifier based on this damage mechanism.
基金National Natural Science Foundation of China(51774179)Natural Science Foundation of Liaoning Province(20180550546)+2 种基金Joint Fund of State Key Laboratory of Metal Material for Marine Equipment and Application(HGSKL-USTLN(2021)03)High-Level Talent Fund of USTL(6003000377,6003000294)supported by Liaoning Provincial Department of Education(LJ212410146037)。
文摘The effect of element Ti on the microstructures and mechanical properties of as-cast and annealed NbTaMoWTi,(x=0,1,1.5,2)refractory high-entropy alloys(RHEAs)was investigated.Results show that after Ti addition,the as-cast alloys maintain their original single body-centered cubic(bcc)structure.As for the mechanical properties,compared with those without Ti addition,the strength and ductility of NbTaMoWTi,alloys increase by 93%and 215%,respectively.Furthermore,the NbTaMoWTi alloys exhibit outstanding thermal stability.After annealing at 1400 C,they still maintain the single bcc structure,and their mechanical properties are even slightly improved.However,annealing leads to a significant deterioration in the mechanical properties of high-Ti-content alloys(NbTaMoWTil and NbTaMoWTi2),owing to the formation of Ti-rich acicular phases.
基金National MCF Energy R&D Program(2024YFE03260300)。
文摘Refractory metals,including tungsten(W),tantalum(Ta),molybdenum(Mo),and niobium(Nb),play a vital role in industries,such as nuclear energy and aerospace,owing to their exceptional melting temperatures,thermal durability,and corrosion resistance.These metals have body-centered cubic crystal structure,characterized by limited slip systems and impeded dislocation motion,resulting in significant low-temperature brittleness,which poses challenges for the conventional processing.Additive manufacturing technique provides an innovative approach,enabling the production of intricate parts without molds,which significantly improves the efficiency of material usage.This review provides a comprehensive overview of the advancements in additive manufacturing techniques for the production of refractory metals,such as W,Ta,Mo,and Nb,particularly the laser powder bed fusion.In this review,the influence mechanisms of key process parameters(laser power,scan strategy,and powder characteristics)on the evolution of material microstructure,the formation of metallurgical defects,and mechanical properties were discussed.Generally,optimizing powder characteristics,such as sphericity,implementing substrate preheating,and formulating alloying strategies can significantly improve the densification and crack resistance of manufactured parts.Meanwhile,strictly controlling the oxygen impurity content and optimizing the energy density input are also the key factors to achieve the simultaneous improvement in strength and ductility of refractory metals.Although additive manufacturing technique provides an innovative solution for processing refractory metals,critical issues,such as residual stress control,microstructure and performance anisotropy,and process stability,still need to be addressed.This review not only provides a theoretical basis for the additive manufacturing of high-performance refractory metals,but also proposes forward-looking directions for their industrial application.
基金supported by the Natural Science Foundation of Shaanxi Province(No.2023-JC-QN-0615)the National Natural Science Foundation of China(Nos.52272027 and 52372034).
文摘Intelligent refractory materials represent a new generation of high-temperature functional materials that significantly enhance the service performance of traditional refractories in extreme environments through integrated sensing,response,and adaptive mechanisms.A comprehensive overview of intelligent refractory materials was provided,focusing on their classification,preparation techniques,and industrial applications.Firstly,the categories and design principles of intelligent refractory materials are introduced,including self-healing,self-regulating,and self-diagnosing types,which enhance durability and performance under extreme conditions.Subsequently,advanced preparation technologies are discussed,such as 3D printing for complex geometries,nanocomposite engineering for improved mechanical and thermal properties,gradient design for optimized thermal stress resistance and information technology including machine learning,health monitoring,digital twin.Finally,the industrial applications of these materials are highlighted,particularly in steel metallurgy,building materials industry,and energy.It aims to bridge the gap between research advancements and practical implementation,offering insights into future trends in intelligent refractory material development.
基金supported by the National Natural Science Foundation of China(Nos.22406081,22276086,22306086)the Natural Science Foundation of Jiangxi Province(No.20232BAB213029),all of which are greatly acknowledged by the authors.
文摘Fenton-like technology based on peroxymonosulfate activation has shown great potential in refractory organics degradation.In this work,single Fe atom catalysts were synthesized through facile ball milling and exhibited very high performance in peroxymonosulfate activation.The Fe single-atom filled an N vacancy on the triazine ring edge of C_(3)N_(4),as confirmed through X-ray absorption fine structure,density functional calculation and elec-tron paramagnetic resonance.The SAFe_(0.4)–C_(3)N_(4)/PMS system could completely remove phenol(20 mg/L)within 10 min and its first-order kinetic constant was 12.3 times that of the Fe_(3)O_(4)/PMS system.Under different ini-tial pH levels and in various anionic environments,SAFe_(0.4)–C_(3)N_(4) still demonstrated excellent catalytic activity,achieving a removal rate of over 90%for phenol within 12 min.In addition,SAFe_(0.4)–C_(3)N_(4) exhibited outstanding selectivity in reaction systems with different pollutants,showing excellent degradation effects on electron-rich pollutants only.Hydroxyl radicals(•OH),singlet oxygen(1O_(2))and high-valent iron oxide(Fe(Ⅳ)=O)were de-tected in the SAFe_(0.4)–C_(3)N_(4)/PMS system through free radical capture experiments.Further experiments on the quenching of active species and a methyl phenyl sulfoxide probe confirmed that 1O_(2) and Fe(Ⅳ)=O played dom-inant roles.Additionally,the change in the current response after adding PMS and phenol in succession proved that a direct electron transfer path between organic matter and the catalyst surface was unlikely to exist in the SAFe_(0.4)–C_(3)N_(4)/PMS/Phenol degradation system.This study provides a new demonstration of the catalytic mech-anism of single-atom catalysts.
基金financially supported by the Key Projects of the National Natural Science Foundation of China(Grant No.U21A2058)Research Project of Hubei Provincial Department of Science and Technology(Grant No.2024CSA075)the Chiping Haoxin Industry Co.,Ltd.,Shandong,China.
文摘High temperature industries are a critical focus for energy conservation and carbon reduction.As fundamental materials for these industries,refractories urgently require the development of high-performance,low thermal conductivity,and long service life materials to support green and low carbon development.To achieve refractories with both low thermal conductivity and excellent service performance,porous anorthite-spinel refractories were developed via in-situ decomposition pore-forming technology.The effects of spinel on microstructure evolution,strength,and thermal conductivity were investigated,supplemented by thermodynamic calculations.The results indicated that the porous anorthite-spinel refractory primarily consisted of anorthite and spinel,with minor corundum.Small-sized spinel particles were uniformly dispersed in the matrix,while the spinel reaction layers forming on the surfaces of large-sized crushed powder particles,wrapping around the remaining unreacted particles.The improvement of the degree of direct bonding between anorthite and spinel in the matrix and the small amount of diffusely distributed in situ spinel forced the deflection of the crack extension paths,which was conducive to the enhancement of the compressive strength of porous anorthite-spinel refractory.The optimized composition had 20 wt.%spinel and its apparent porosity and cold compressive strength were 43.6%and 37.8 MPa.Compared to porous anorthite refractories,the porous anorthite-spinel refractories exhibited a 21%reduction in thermal conductivity(500℃),and a 12%improvement in cold compressive strength.Valuable insights for the resource utilization of corundum dust and the design of energy efficient refractory insulation layers in high temperature industries are provided by this study.
文摘The deformation characteristics and activation mechanisms of kink bands in refractory multi-principal element alloys with local chemical fluctuations(LCFs)were systematically studied.These alloys were fabricated using laser-directed energy deposition technology and characterized by room-temperature compression testing,electron backscatter diffraction(EBSD),transmission electron microscopy(TEM),and high-angle annular dark-field(HAADF)imaging.The results reveal that kinking is a gradual rotational diffusion process,during which the misorientation difference between the kink and the matrix varies.A low Schmid factor is a prerequisite for kink excitation.The slip system closest to the loading axis is passively activated by the applied external force,leading to the accumulation of geometrically necessary dislocations(GNDs)required for lattice rotation.The widespread LCFs within the matrix reduce the migration rate of edge dislocations,promoting GND accumulation and enhancing the propensity for kink band formation.During deformation,the occurrence of kinking enables continuous lattice rotation to accommodate the exceptionally high strain in the vicinity,when the stress concentration in the primary kink cannot be fully released,double kinks are activated to reduce strain energy.
基金supported by the National Key R&D Program of China(Grant No.2023YFB3508700)the National Natural Science Foundation of China(NSFC,Grant Nos.52227801 and 52271162)the Fundamental Research Funds for the Central Universities.
文摘Exploiting effective approaches to achieve superior ductility has consistently been a topic of widespread interest in refractory multi-principal-element alloys(RMPEAs).Herein,we developed a one-step forming method,electron-beam directional-solidification(EB-DS),to fabricate an equiatomic Hf-Nb-Ta-Zr RMPEA,and compared its microstructures as well as mechanical properties with those of the as-cast alloy fabricated by levitation induction melting.EB-DS method can transform the equiaxed grain microstructures in the as-cast alloy to columnar grain microstructures as well as eliminate the slight segregation.The room-temperature tensile test demonstrates that the ductility is substantially improved from 3.9%for the as-cast alloy to 23%for EB-DS alloy,accompanied by the slight enhancement in yield strength from 946 to 991 MPa.The microstructural investigations indicate that EB-DS alloys with columnar grains present a significantly optimized coordinated plastic deformation between the grain boundary region and the grain interior region,leading to the suppression of cracking along grain boundaries.
基金supported by the National Natural Science Foundation of China(No.51974016).
文摘Microwave roasting self-leaching is an innovative method for recovering gold from high-sulfur refractory gold concentrates,without using deadly toxic cyanide reagents.However,the mechanism of gold self-leaching,which relies on lixiviants prepared using volatilized sulfur obtained from roasting,has not been fully elucidated.This study employs the response surface methodology to optimize processing parameters,resulting in an increased gold extraction rate of 96.18%.Analytical factorization and the Tafel curve indicate that CuSO_(4) and NH_(3)·H_(2)O significantly influence the self-leaching process.Furthermore,X-ray photoelectron spectroscopy(XPS)analysis reveals that S^(2−),S_(2)^(2−),polysulfides(S_(n)^(2−)),and thiosulfate(S_(2)O_(3)^(2−))are involved in the gold leaching reaction,with S^(2−),S_(2)^(2−),and S_(n)^(2−) serving as primary ligands for gold complexation.The role of S_(2)O_(3)^(2−) in the early stages of the gold-leaching reaction is also noteworthy.The copper–ammonia complex catalyzes the self-leaching gold reaction;however,an improper addition ratio can lead to copper-sulfur compound precipitates,reducing the extraction rate.
基金supported by the National Natural Science Foundation of China(Nos.52274331 and 52264041)Guizhou Basic Research Program(Natural Science)Talent Team Lift Project(QNB[2025]005)+2 种基金supported by Guizhou Provincial Basic Research Program(Natural Science)(ZK[2023]Zhongdian 020)Guizhou Provincial Young Elite Scientist Sponsorship Program by Gast(No.Gastyess202405)Key Research Projects in Higher Education Institutions of Henan Province(No.24B450003).
文摘The effects of ZrO_(2)-based refractory materials on non-metallic inclusions in nickel-based superalloy K4169 were systematically investigated.Analytical methods,including X-ray fluorescence,X-ray diffraction,scanning electron microscopy equipped with energy dispersive spectrometry,and FactSage simulations,revealed that the refractory primarily consisted of ZrO_(2),MgO,MgO·Al_(2)O_(3),and Zr_(1.74)Y_(0.26)O_(3.87) phases.During melting,MgO reacted with[Al]and[O]in the alloy,forming MgO·Al_(2)O_(3) at the interface.This phase adhered to the superalloy,while ZrO_(2) phases remained stable.The inclusions in the alloy transformed from Al_(2)O_(3) to MgO·Al_(2)O_(3),with variations in size and distribution influenced by location and pressure.FactSage kinetic simulations aligned with experimental findings,elucidating the interaction mechanisms between the alloy and refractory.These results provide insights into optimizing refractory materials for improved cleanliness and performance in nickel-based superalloy production.
文摘1 Production and Running Status of China’s Refractories Industry in 20241.1 Production and Running Status In 2024,according to the statistical data from The Association of China Refractories Industry,China’s refractories output was 22.0711million tons,decreasing by 3.73%YOY;in which the outputs of dense shaped refractory products,insulating refractory products and monolithic refractories were 11.3163 million tons decreasing by 6.07%YOY,83.77 thousand tons increasing by 11.17%YOY,and 9.9971 million tons decreasing by 2.07%YOY,respectively.The outputs of the main varieties are shown in Fig.1.
基金Supported by Science and Technology Project of Sichuan Provincial Health Commission(No.24WXXT13)North Sichuan Medical College Doctor Start-up Fund Project(No.CBY24-QDA01).
文摘Dear Editor,I diopathic macular telangiectasia(MacTel)type 1 is a retinal vascular disease characterized by abnormal dilation of macular capillaries,leading to metamorphopsia,progressive vision loss,and temporal scotoma enlargement.Currently,there is no standardized treatment protocol for MacTel type 1[1-2].Treatment outcomes can vary significantly among individuals,highlighting the ongoing need for further exploration of new and more effective treatment options.This paper presents a case of refractory macular edema associated with MacTel type 1,which showed a favorable response to pars plana vitrectomy(PPV)and internal limiting membrane(ILM)peeling.
基金supports received from Scientific Research Fund of Liaoning Province Education Department(Grant No.JYTQN 2023025)Scientific Research Fund of Liaoning Province Education Department(Grant No.JYTQN 2023025)+3 种基金the Natural Science Foundation of Liaoning Province(Grant No.2024-MS-075)the National Natural Science Foundation of China(32201179)National Key R&D Program of China(2023YFC2508200)Liaoning Provincial Natural Science Foundation Joint Fund(General Support Program Project)(2023-MSBA-093).
文摘Refractory wounds cause significant harm to the health of patients and the most common treatments in clinical practice are surgical debridement and wound dressings.However,certain challenges,including surgical difficulty,lengthy recovery times,and a high recurrence rate persist.Conductive hydrogel dressings with combined monitoring and therapeutic properties have strong advantages in promoting wound healing due to the stimulation of endogenous current on wounds and are the focus of recent advancements.Therefore,this review introduces the mechanism of conductive hydrogel used for wound monitoring and healing,the materials selection of conductive hydrogel dressings used for wound monitoring,focuses on the conductive hydrogel sensor to monitor the output categories of wound status signals,proving invaluable for non-invasive,real-time evaluation of wound condition to encourage wound healing.Notably,the research of artificial intelligence(AI)model based on sensor derived data to predict the wound healing state,AI makes use of this abundant data set to forecast and optimize the trajectory of tissue regeneration and assess the stage of wound healing.Finally,refractory wounds including pressure ulcers,diabetes ulcers and articular wounds,and the corresponding wound monitoring and healing process are discussed in detail.This manuscript supports the growth of clinically linked disciplines and offers motivation to researchers working in the multidisciplinary field of conductive hydrogel dressings.
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 Key Research and Development Program of China(Grant No.2022YFF0609000)National Natural Science Foundation of China(Grant Nos.52171034 and 52101037)Postdoctoral Fellowship Program of CPSFara(No.GZB20230944).
文摘Up-and-coming high-temperature materials,refractory high entropy alloys,are suffering from lower oxidation resistance,restricting their applications in the aerospace field.In this study,two novel treatments of Al-deposited and remelted were developed to refine the microstructure and enhance the oxidation resistance of refractory high entropy alloy using electron beam freeform fabrication(EBF3).Finer and short-range ordering structures were observed in the remelted sample,whereas the Al-deposited sample showcased the formation of silicide and intermetallic phases.High-temperature cyclic and isothermal oxidation tests at 1000℃ were carried out.The total weight gain after 60 h of cyclic oxidation decreased by 17.49%and 30.46%for the remelted and deposited samples,respectively,compared to the as-cast state.Oxidation kinetics reveal an evident lower mass gain and oxidation rate in the treated samples.A multilayer oxide consisting of TiO_(2)+Al_(2)O_(3)+SiO_(2)+AlNbO_(4) was studied for its excellent oxidation resistance.The oxidation behavior of rutile,corundum and other oxides was analyzed using first principles calculations and chemical defect analysis.Overall,this research,which introduces novel treatments,offers promising insights for enhancing the inherent oxidation resistance of refractory high entropy alloys.
基金Supported by the Shanghai Science and Technology Committee Project Foundation(No.21Y11909700)Guangci Innovative Technology Sailing Plan(Ruijin Hospital 2022).
文摘AIM:To assess the efficacy and safety of ultrasound cycloplasty(UCP)in lowering intraocular pressure(IOP)among Chinese patients suffering from refractory glaucoma.METHODS:In this 12-month retrospective study,28 patients with refractory glaucoma(IOP≥25 mm Hg)were treated with 8-second UCP using either 8 or 10 probe sectors.The principal measure of efficacy was the decrease in IOP at the following intervals after UCP:1d,1,3,6,and 12mo,with each measurement compared to baseline.RESULTS:Mean IOP(in mm Hg)was reduced from 46.8±8.9 to 24.5±3.2,27.0±4.8,29.1±4.6,26.1±4.5,and 28.3±4.8 at 1d,1,3,6,and 12mo postoperatively,respectively.Compared to baseline,IOP reductions at these time points were 45.0%,39.9%,35.3%,41.4%,and 36.7%,respectively.Most patients experienced relief from ocular pain after surgery.No cases of choroidal detachment or hypotony was observed.CONCLUSION:UCP is effective in reducing IOP among Chinese patients with refractory glaucoma and shows a favorable safety profile.
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sponsored by Shanghai Roche Pharmaceuticals Ltd.
文摘Diffuse large B-cell lymphoma(DLBCL),the most common subtype of non-Hodgkin’s lymphoma(NHL)worldwide,accounts for 39% and 44% of nodal and extranodal NHL cases in China,respectively1.Standard first-line treatment for DLBCL is chemo-immunotherapy with rituximab,cyclophos-phamide,doxorubicin,vincristine,and prednisone,which cures 50%-60% of patients2.
基金financially supported by the National Natural Science Foundation of China(Nos.52201171,52225103,U2441262,51921001,and 12335017)the Fundamental Research Funds for the Central Universities,China(No.FRF-IDRY-23-001)+1 种基金National Key Re-search and Development Program of China(No.2022YFB4602101)the China heavy-duty gas turbine technology Co.Ltd under the project of J721.
文摘Advanced structural materials with superb mechanical properties at ultrahigh temperatures are essential for aerospace and power-generation sectors.Refractory multi-principal element alloys(RMPEAs)are promising candidates,but they face challenges such as limited plasticity at room temperatures and insufficient strength at ultrahigh temperatures.In this work,we investigated the mechanical properties and microstructures of RMPEA reinforced with compositional complex carbides and demonstrated that tailoring the carbon content can significantly alter their microstructures and enhance mechanical properties.Specifically,the W_(30)Ta_(30)Mo_(15)Nb_(15)C_(10)alloy achieved an ultrahigh strength of 896 MPa at 1600℃ and a plasticity of∼8%at room temperatures.The strengthening effect arises from multi-principal element mixing and robust dislocation hindering at the phase interfaces between the carbides and the matrix,while the room temperature plasticity is attributed to crack buffering facilitated by the highly saturated solid solution matrix.Our study highlights the potential of compositional complex carbide to enhance the mechanical properties of RMPEAs,offering a promising approach for the development of advanced structural materials for ultrahigh temperature applications.
基金supported by the National Natural Science Foundation of China(Nos.52371128,52304378,52101031 and 92163107).
文摘Grain boundary engineering plays a significant role in the improvement of strength and plasticity of alloys. However, in refractory high-entropy alloys, the susceptibility of grain boundaries to oxygen presents a bottleneck in achieving high mechanical performance. Creating a large number of clean grain boundaries in refractory high-entropy alloys is a challenge. In this study, an ultrafine-grained (UFG) NbMoTaW alloy with high grain-boundary cohesion was prepared by powder metallurgy, taking advantages of rapid hot-pressing sintering and full-process inert atmosphere protection from powder synthesis to sintering. By oxygen control and an increase in the proportion of grain boundaries, the segregation of oxygen and formation of oxides at grain boundaries were strongly mitigated, thus the intrinsic high cohesion of the interfaces was preserved. Compared to the coarse-grained alloys prepared by arc-melting and those sintered by traditional powder metallurgy methods, the UFG NbMoTaW alloy demonstrated simultaneously increased strength and plasticity at ambient temperature. The highly cohesive grain boundaries not only reduce brittle fractures effectively but also promote intragranular deformation. Consequently, the UFG NbMoTaW alloy achieved a high yield strength even at elevated temperatures, with a remarkable performance of 1117 MPa at 1200 ℃. This work provides a feasible solution for producing refractory high-entropy alloys with low impurity content, refined microstructure, and excellent mechanical performance.
