This study investigates the bond performance at the interfacial region shared by Ultra-High Performance Concrete(UHPC)and steel tubes through push-out tests.This study examines how changes in steel fiber volumetric ra...This study investigates the bond performance at the interfacial region shared by Ultra-High Performance Concrete(UHPC)and steel tubes through push-out tests.This study examines how changes in steel fiber volumetric ratio and thickness of steel tube influence the bond strength characteristics.The results show that as the enhancement of the steel tube wall thickness,the ultimate bond strength at the interface improves significantly,whereas the initial bond strength exhibits only slight variations.The influence of steel fiber volumetric ratio presents a nonlinear trend,with initial bond strength decreasing at low fiber content and increasing significantly as fiber content rises.Additionally,finite element(FE)simulations were applied to replicate the experimental conditions,and the outcomes showed strong correlation with the experimental data,confirming the exactitude of the FE model in predicting the bond behavior at the UHPC-Steel interface.These findings provide valuable insights for optimizing the design of UHPC-Filled steel tubes in high-performance structure.展开更多
Poly(vinylidene fluoride)(PVDF)foam has received widespread attention due to its high strength,and excellent combination of flame-retardancy,antibacterial performance,and chemical stability.However,the foaming ability...Poly(vinylidene fluoride)(PVDF)foam has received widespread attention due to its high strength,and excellent combination of flame-retardancy,antibacterial performance,and chemical stability.However,the foaming ability of conventional PvDF is severely limited by its rapid crystallization kinetics and poor melt strength.Although ultra-high molecular weight PVDF(H-PVDF)theoretically offers prolonged melt elasticity favorable for foaming,the extremely high melt viscosity poses substantial processing challenges,and its foaming behavior has remained largely unexplored.To address these issues,this study proposes a novel fabrication strategy combining solvent casting with microcellular foaming to prepare H-PVDF foams.Dynamic mechanical analysis and differential scanning calorimetry reveal that extensive chain entanglements in H-PVDF impose constraints on crystallization and significantly enhance melt strength.By tuning the processing parameters,the distinctive foaming be-havior of H-PVDF under various conditions is systematically elucidated.Remarkably,a record-high expansion ratio of 55.6-fold is achieved,ac-companied by a highly uniform and fine cellular structure.The resulting H-PVDF foams exhibit a low thermal conductivity of 31.8 mW·m^(-1).K^(-1),while retaining excellent compressive strength,flame-retardancy,and hydrophobicity.These outstanding properties highlight the great potential of H-PVDF foams as the thermal insulation materials for applications in aerospace,energy infrastructure,and other extreme environments.展开更多
Ultra-high strength steel(UHSS)fabricated via laser additive manufacturing(LAM)holds significant promise for applications in defense,aerospace,and other high-performance sectors.However,its response to high-impact loa...Ultra-high strength steel(UHSS)fabricated via laser additive manufacturing(LAM)holds significant promise for applications in defense,aerospace,and other high-performance sectors.However,its response to high-impact loading remains insufficiently understood,particularly regarding the influence of energy density on its dynamic mechanical behavior.In this study,scanning electron micro-scopy,electron backscatter diffraction,and image recognition techniques were employed to investigate the microstructural variations of LAM-fabricated UHSS under different energy density conditions.The dynamic mechanical behavior of the material was characterized using a Split Hopkinson Pressure Bar system in combination with high-speed digital image correlation.The study reveals the spatiotemporal evolution of surface strain and crack formation,as well as the underlying dynamic fracture mechanisms.A clear correlation was established between the microstructures formed under varying energy densities and the resulting dynamic mechanical strength of the material.Results demonstrate that optimal material density is achieved at energy densities of 292 and 333 J/mm^(3).In contrast,energy densities exceeding 333 J/mm^(3) induce keyhole defects,compromising structural integrity.Dynamic performance is strongly dependent on material density,with peak impact resistance observed at 292 J/mm^(3)-where strength is 8.4%to 17.6%higher than that at 500 J/mm^(3).At strain rates≥2000 s^(-1),the material reaches its strength limit at approximately 110μs,with the initial crack appearing within 12μs,followed by rapid failure.Conversely,at strain rates≤1500 s^(-1),only microcracks and adiabatic shear bands are detected.A transition in fracture surface morphology from ductile to brittle is observed with increasing strain rate.These findings offer critical insights into optimizing the dynamic mechanical properties of LAM-fabricated UHSS and provide a valuable foundation for its deployment in high-impact environments.展开更多
It is well known that transition metal sulfides(TMS)(i.e.,NiS_(2))undergo electrochemical reconstructions to generate highly active Ni_(3)S_(2) during the process of hydrogen evolution reaction(HER)under overpotential...It is well known that transition metal sulfides(TMS)(i.e.,NiS_(2))undergo electrochemical reconstructions to generate highly active Ni_(3)S_(2) during the process of hydrogen evolution reaction(HER)under overpotentials of<500 mV.However,at higher overpotentials,Ni_(3)S_(2) can theoretically be further restructured into Ni and thus form Ni/Ni_(3)S_(2) heterogeneous interface structures,which may provide opportunities to further enhance HER activity of NiS_(2).Here,we selected NiS_(2) as a model electrocatalyst and investigated the influence of the reconstruction results induced from regular to ultrahigh overpotentials on its electrocatalytic hydrogen precipitation performance.The experimental results showed that the most significant enhancement of hydrogen precipitation performance was obtained for the NiS_(2)@CC-900(900 means 900 mV overpotential)sample after the ultra-high overpotential induced reconstruction.Compared with the initial overpotential of 161 mV(10 mA cm^(-2)),the overpotential of the reconstructed sample reduced by 67 mV(42%).The characterization results showed that an ultra-high overpotential of 900 mV induced deep reconstruction of NiS_(2),formed highly reactive Ni/Ni_(3)S_(2) heterogeneous interfaces,which is more conducive to improved HER performance and match well with theoretical calculations results.We demonstrated ultrahigh overpotential was an effective strategy to induce NiS_(2) deeply reconstruction and significantly improve its HER performance,and this strategy was also applicable to CoS_(2) and FeS_(2).This study provides an extremely simple and universal pathway for the reasonable construction of efficient electrocatalysts by induced TMS deeply reconstruction.展开更多
Ultra-high dose rate flash radiotherapy(FLASH-RT)has attracted wide attention in the field of radiotherapy in recent years.For FLASH-RT,radiation is delivered at a very high dose rate[usually thousands of times compar...Ultra-high dose rate flash radiotherapy(FLASH-RT)has attracted wide attention in the field of radiotherapy in recent years.For FLASH-RT,radiation is delivered at a very high dose rate[usually thousands of times compared with conventional radiotherapy(CONV-RT)]in an extremely short time.This novel irradiation technique shows a protective effect on normal tissues,also known as the flash effect.At the same time,FLASH-RT is comparable to CONV-RT in terms of tumorkilling efficacy.As basic research dedicates to uncover the mechanisms by which FLASH-RT reduces radiation-induced normal tissue damage,clinical trials of FLASH-RT have been gradually conducted worldwide.This article systematically reviews the evidence of the feasibility and safety of FLASH-RT in clinical practice and offers insights into the future translation of this technology in clinic.展开更多
The effects of prior austenite and primary carbides on the mechanical properties of a novel 2.5 GPa grade steel were investigated by treating at various solid-solution temperatures.The ultimate tensile strength and Ch...The effects of prior austenite and primary carbides on the mechanical properties of a novel 2.5 GPa grade steel were investigated by treating at various solid-solution temperatures.The ultimate tensile strength and Charpy U-notch impact energy initially increased and subsequently decreased as the solid-solution temperature rose,while the yield strength consistently decreased.The size of prior austenite grain and martensite block always increased with rising the solid-solution temperature,and austenite grain growth activation energy is 274,969 J/mol.The growth of prior austenite was restricted by primary carbides M6C and MC.The dissolution of the primary carbides not only enhanced solid-solution strengthening and secondary hardening effects but also increased the volume fraction of retained austenite.The increase in the ultimate tensile strength and Charpy U-notch impact energy was primarily attributed to the dissolution of the primary carbides M6C and MC,while the decrease was due to the increase in the size of prior austenite grain and martensite block.Exceptional combination of strength,ductility and toughness with ultimate tensile strength of 2511 MPa,yield strength of 1920 MPa,elongation of 9.5%,reduction of area of 41%and Charpy U-notch impact energy of 19.5 J was obtained when experimental steel was solid-solution treated at 1020℃.展开更多
Integrating thick/thin film sensors into component systems has emerged as a prevalent approach for monitoring in extreme environments.However,traditional vapor deposition methods face obstacles,including complex fabri...Integrating thick/thin film sensors into component systems has emerged as a prevalent approach for monitoring in extreme environments.However,traditional vapor deposition methods face obstacles,including complex fabrication processes and the degradation of sensitive materials at extremely high temperatures.This work delineates the development of a polysilazane composite dual-layer thick-film Negative Temperature Coefficient(NTC)thermistor characterized by its suitability for extreme temperatures and robust bond strength achieved through an advanced near-net-shape printing methodology.High-temperature resistant La(Ca)CrO_(3)/polysilazane films were printed as the sensitive layer,while a dense layer formed by Cr_(2)O_(3)/polysilazane was used as the protective layer.The bilayer structure resulted in a 2.5-fold increase in adhesion strength compared to the single-layer La(Ca)CrO_(3)/polysilazane films.Experimental results indicate that the dual-layer thick-film NTC thermistor can be operated long-term at 1300℃ with a resistance drift rate of 0.9%/h and survive short-term exposure to temperatures up to 1550℃.As a proof of concept,this work applied 3D printing technology to fabricate a polysilazane composite dual-layer thick-film NTC thermistor on the surface of turbine blades and demonstrated its functionality under flame impingement at nearly 1300℃.Such flexible 3D printing techniques pave the way for a new paradigm in manufacturing sensors capable of withstanding ultra-high temperatures.展开更多
Background:Polygonum multiflorum-induced liver injury(PM-DILI)has significantly hindered its clinical application and development.Methods:This study investigates the variation in content and toxicity of dian-thrones,t...Background:Polygonum multiflorum-induced liver injury(PM-DILI)has significantly hindered its clinical application and development.Methods:This study investigates the variation in content and toxicity of dian-thrones,the toxic components of P.multiflorum,during different processing cycles.We employed the ultra-high-performance liquid chromatography triple quadrupole mass spectrometry method to quantify six dianthrones in raw P.multiflorum and formulations processed with a method called nine cycles of steaming and sunning.Additionally,toxicity assessments were conducted using human normal liver cell line L02 and zebrafish embryos.Results:Results indicate a gradual reduction in dianthrones content with increasing processing cycles.Processed formulations exhibited significantly reduced cytotoxic-ity in L02 cells and hepatotoxicity in zebrafish embryos.Conclusions:Our findings elucidate the relationship between processing cycles and P.multiflorum toxicity,providing theoretical support for its safe use.展开更多
Currently,the enhancement in electromagnetic interference(EMI)performance of polymeric composite generally relies on either improving electrical conductivity(σ)for stronger electromagnetic(EM)reflections or tailoring...Currently,the enhancement in electromagnetic interference(EMI)performance of polymeric composite generally relies on either improving electrical conductivity(σ)for stronger electromagnetic(EM)reflections or tailoring structure for higher EM resonances.Herein,we proposed a novel technique called cyclic pulsating pressure enhanced segregating structuration(CPP-SS),which can reinforce these two factors simultaneously.The structural information was supplied by optical microscopy(OM)and scanning electron microscopy(SEM),both of which confirmed the formation and evolution of segregate structured ultra-high molecular weight polyethylene(UHMWPE)/graphene composites.Then,the result showed that CPP-SS can significantly improve theσof samples.Ultimately,advanced specific EMI shielding efficiency of 31.1 d B/mm was achieved for UHMWPE/graphene composite at 1-mm thickness and a low graphene loading of 5 wt%.Meanwhile,it also confirmed that the intrinsic disadvantage of poor mechanical properties of conventional segregated structure composites can be surpassed.This work is believed to provide a fundamental understanding of the structural and performance evolutions of segregated structured composites prepared under CPPSS,and to bring us a simple and efficient approach for fabricating high-performance,strong and light-weight polymeric EMI shields.展开更多
To achieve higher strength and better durability,ultra-high performance concrete(UHPC)typically employs a relatively small water-binder ratio.However,this generally leads to an undesired increase in the paste viscosit...To achieve higher strength and better durability,ultra-high performance concrete(UHPC)typically employs a relatively small water-binder ratio.However,this generally leads to an undesired increase in the paste viscosity.In this study,the effects of liquid and powder polycarboxylate superplasticizers(PCE)on UHPC are compared and critically discussed.Moreover,the following influential factors are considered:air-entraining agents(AE),slump retaining agents(SA),and defoaming agents(DF)and the resulting flow characteristics,mechanical properties,and hydration properties are evaluated assuming UHPC containing 8‰powder PCE(PCE-based UHPC).It is found that the spread diameter of powder PCE is 5%higher than that of liquid PCE.Among the chemical admixtures studied,AEs have the best effect on improving UHPC workability,while DFs have the worst effect.When the addition of AE and SA is 1.25‰and 14.7%of PCE,paste viscosity reduces by 35%and 19%,respectively compared to the paste with only 8‰PCE.A low AE dosage(1.25‰)decreases compressive strength by 4.1%,while SA(8.1%)increases UHPC compressive strength by 9.1%.Both AE and SA significantly delay the UHPC hydration process,reducing the hydration heat release peaks by 76%and 27%,respectively.展开更多
Due to the low water-cement ratio of ultra-high-performance concrete(UHPC),fluidity and shrinkage cracking are key aspects determining the performance and durability of this type of concrete.In this study,the effects ...Due to the low water-cement ratio of ultra-high-performance concrete(UHPC),fluidity and shrinkage cracking are key aspects determining the performance and durability of this type of concrete.In this study,the effects of different types of cementitious materials,chemical shrinkage-reducing agents(SRA)and steel fiber(SF)were assessed.Compared with M2-UHPC and M3-UHPC,M1-UHPC was found to have better fluidity and shrinkage cracking performance.Moreover,different SRA incorporation methods,dosage and different SF types and aspect ratios were implemented.The incorporation of SRA and SF led to a decrease in the fluidity of UHPC.SRA internal content of 1%(NSRA-1%),SRA external content of 1%(WSRA-1%),STS-0.22 and STE-0.7 decreased the fluidity of UHPC by 3.3%,8.3%,9.2%and 25%,respectively.However,SRA and SF improved the UHPC shrinkage cracking performance.NSRA-1%and STE-0.7 reduced the shrinkage value of UHPC by 40%and 60%,respectively,and increased the crack resistance by 338%and 175%,respectively.In addition,the addition of SF was observed to make the microstructure of UHPC more compact,and the compressive strength and flexural strength of 28 d were increased by 26.9%and 19.9%,respectively.展开更多
Ultra-high temperature ceramics(UHTCs) offer great potential for applications in extreme service environments,such as hypersonic vehicles,rockets and re-entry spacecraft.However,the severe ablation caused by highspeed...Ultra-high temperature ceramics(UHTCs) offer great potential for applications in extreme service environments,such as hypersonic vehicles,rockets and re-entry spacecraft.However,the severe ablation caused by highspeed heat flow scouring and high-temperature oxidation limits the engineering application of UHTCs.In this work,we report a novel high-entropy UHTC(Ti_(0.2)Zr_(0.2)V_(0.2)Nb_(0.2)Cr_(0.2))(C_(0.5)N_(0.5)),which exhibits superior ablation resistance and light weight compared with traditional UHTCs.Specifically,at a temperature of 2650 K,the mass ablation rate of the material was measured as1.025×10^(-2)g·s^(-1),and the density was calculated to be 6.7 g·cm^(-3).The impressive ablation resistance of(Ti_(0.2)Zr_(0.2)V_(0.2)Nb_(0.2)Cr_(0.2))(C_(0.5)N_(0.5)) is attributed to the incorporation of a self-healing mechanism,which is associated with the in-situ formation of a medium-entropy oxide(TiVCr)O_(2) during the ablation process.The mediumentropy oxide can seal pores and cracks to retard oxygen diffusion and prevent the material from fragmentation,thereby resulting in outstanding ablation resistance.展开更多
We developed ultra-high performance concrete(UHPC)incorporating mullite sand and brown corundum sand(BCS),and the quartz sand UHPC was utilized to prepare for comparison.The properties of compressive strength,elastic ...We developed ultra-high performance concrete(UHPC)incorporating mullite sand and brown corundum sand(BCS),and the quartz sand UHPC was utilized to prepare for comparison.The properties of compressive strength,elastic modulus,ultrasonic pulse velocity,flexural strength,and toughness were investigated.Scanning electron microscopy and nanoindentation were also conducted to reveal the underlying mechanisms affecting macroscopic performance.Due to the superior interface bonding properties between mullite sand and matrix,the compressive strength and flexural toughness of UHPC have been significantly improved.Mullite sand and BCS aggregates have higher stiffness than quartz sand,contributing to the excellent elastic modulus exhibited by UHPC.The stiffness and volume of aggregates have a more significant impact on the elastic modulus of UHPC than interface performance,and the latter contributes more to the strength of UHPC.This study will provide a reference for developing UHPC with superior elastic modulus for structural engineering.展开更多
Artificial macrocycle with high binding selectivity in water is often challenging but urgently needed in various research and application areas.Herein,we report a new water-soluble biomimetic tetralactam macrocycle an...Artificial macrocycle with high binding selectivity in water is often challenging but urgently needed in various research and application areas.Herein,we report a new water-soluble biomimetic tetralactam macrocycle and realize the ultra-high selectivity to nucleosides over corresponding monophosphate nucleotides by rational modification.The introduction of charged groups at the periphery of endofunctionalized cavity makes the selectivity(guanosine to guanosine 5-monophosphate)increase remarkably from 100 to 1119.Based on the ultra-high selectivity of biomimetic tetralactam macrocycle,the sensitive CD73 enzyme activity assay was then achieved through product-selective fluorescence indicator displacement assay.Furthermore,the capability of the proposed method for inhibitor screening was successfully displayed.展开更多
High-density carbon/carbon(C/C)composite plays a critical role in the aerospace industry owing to excellent mechanical properties and resistance to ablation.However,traditional manufacturing relies on pitch precursor ...High-density carbon/carbon(C/C)composite plays a critical role in the aerospace industry owing to excellent mechanical properties and resistance to ablation.However,traditional manufacturing relies on pitch precursor and hot isostatic pressure impregnation and carbonization(HIPIC)technology,which is time-consuming and expensive.In this study,we report an innovative method utilizing polyarylacetylene(PAA)resin and ultra-high pressure impregnation and carbonization(UHPIC)technology.The extremely high char yield of PAA resin(85 wt.%)and high isotropic pressure of UHPIC(over 200 MPa)promote the densification of the composite.As a result,we achieve a high-density(1.90 g/cm^(3))C/C composite with a high degree of graphitization(81%).This composite exhibits impressive properties,including flexural strength of 146 MPa,compressive strength of 187 MPa,and thermal conductivity of 147 W/(m K).When exposed to oxyacetylene flame at 3000 K for 100 s,it displays minimal linear ablation,with a rate of 1.27×10^(-2)mm/s.This study demonstrates the exceptional graphitizable characteristic of PAA resin,setting it apart from conventional resins.Our time-saving and cost-effective approach holds significant promise for aerospace applications,particularly in harsh aerodynamic heating environments.展开更多
Ultra-high nickel cobalt-free lithium layered oxides are promising cathode material for lithium-ion batteries(LIBs)because of their relatively high capacity and low cost.Nevertheless,the high nickel content would indu...Ultra-high nickel cobalt-free lithium layered oxides are promising cathode material for lithium-ion batteries(LIBs)because of their relatively high capacity and low cost.Nevertheless,the high nickel content would induce bulk structure degradation and interfacial environment deterioration,and the absence of Co element reduces the lithium diffusion kinetics,severely limiting the performance liberation of this kind of cathodes.Herein,a multifunctional Ti/Zr dual cation co-doping strategy has been employed to improve the lithium storage performance of LiNi_(0.9)Mn_(0.1)O_(2)(NM91)cathode.On the one hand,the Ti/Zr co-doping weakens the Li^(+)/Ni^(2+)mixing through magnetic interactions due to the inexistence of unpaired electrons for Ti^(4+)and Zr^(4+),increasing the lithium diffusion rate and suppressing the harmful coexistence of H1 and H2 phases.On the other hand,they enhance the lattice oxygen stability because of the strong Ti-O and Zr-O bonds,inhibiting the undesired H3 phase transition and lattice oxygen loss,improving the bulk structure and cathode-electrolyte interface stability.As a result,the Ti/Zr co-doped NM91(NMTZ)exhibits a 91.2%capacity retention rate after 100 cycles,while that of NM91 is only82.9%.Also,the NMTZ displays better rate performance than NM91 with output capacities of 115 and93 mA h g^(-1)at a high current density of 5 C,respectively.Moreover,the designed NMTZ could enable the full battery to deliver an energy density up to 263 W h kg^(-1),making the ultra-high nickel cobaltfree lithium layered oxide cathode closer to practical applications.展开更多
Achieving high fouling resistance and permeability using membrane separation technology in water treatment processes remains a challenge.In this work,a novel mixed-matrix membrane(MMM)(poly(arylene ether ketone)[PAEK]...Achieving high fouling resistance and permeability using membrane separation technology in water treatment processes remains a challenge.In this work,a novel mixed-matrix membrane(MMM)(poly(arylene ether ketone)[PAEK]-containing carboxyl groups[PAEK-COOH]/UiO-66-NH_(2)@graphene oxide[GO])with superb fouling resistance and high permeability was prepared by the nonsolvent-induced phase separation method,by in-situ growth of UiO-66-NH_(2) on the GO layer,and by preparing hydrophilic PAEK-COOH.On the basis of the structure and performance analysis of the MMM,the maximum water flux reached 591.25 L·m^(-2)·h^(-1) for PAEK-COOH/UiO-66-NH_(2)@GO,whereas the retention rate for bovine serum albumin increased from 85.40%to 94.87%.As the loading gradually increased,the hydrophilicity of the MMMs increased,significantly enhancing their fouling resistance.The strongest anti-fouling ability observed was 94.74%,which was 2.02 times greater than that of the pure membrane.At the same time,the MMMs contained internal amide and hydrogen bonds during the preparation process,forming a cross-linked structure,which further enhanced the mechanical strength and chemical stability.In summary,the MMMs with high retention rate,strong permeability,and anti-fouling ability were successfully prepared.展开更多
An accurate mapping and understanding of remaining oil distribution is very important for water control and stabilize oil production of mature oilfields in ultra-high water-cut stage.Currently,the Tuo-21 Fault Block o...An accurate mapping and understanding of remaining oil distribution is very important for water control and stabilize oil production of mature oilfields in ultra-high water-cut stage.Currently,the Tuo-21 Fault Block of the Shengtuo Oilfield has entered the stage of ultra-high water cut(97.2%).Poor adaptability of the well pattern,ineffective water injection cycle and low efficiency of engineering measures(such as workover,re-perforation and utilization of high-capacity pumps)are the significant problems in the ultra-high water-cut reservoir.In order to accurately describe the oil and water flow characteristics,relative permeability curves at high water injection multiple(injected pore volume)and a semiquantitative method is applied to perform fine reservoir simulation of the Sand group 3e7 in the Block.An accurate reservoir model is built and history matching is performed.The distribution characteristics of remaining oil in lateral and vertical directions are quantitatively simulated and analyzed.The results show that the numerical simulation considering relative permeability at high injection multiple can reflect truly the remaining oil distribution characteristics after water flooding in an ultrahigh water-cut stage.The distribution of remaining oil saturation can be mapped more accurately and quantitatively by using the‘four-points and five-types’classification method,providing a basis for potential tapping of various remaining oil types of oil reservoirs in late-stage of development with high water-cut.展开更多
To address the inhomogeneous microstructure and improve the mechanical properties of DT300 ultra-high strength steel specimens fabricated by laser powder bed fusion,different post-heat treatment schedules are performe...To address the inhomogeneous microstructure and improve the mechanical properties of DT300 ultra-high strength steel specimens fabricated by laser powder bed fusion,different post-heat treatment schedules are performed.With the increase in austenitizing temperature and time,the migration rate of austenite grain boundaries continuously increases with the dissolution of nano-carbides,and the formation of nano-oxides and twin martensite is also inhibited accordingly.The rapid growth in the size of prior austenite grains and martensite laths,as well as the decrease in the content of nano-oxides and twin martensite,led to a rapid decrease in the strength(yield strength and ultimate tensile strength)from HT2 to HTF specimens.The HT1 specimens(austenitizing at 830℃for 30 min,then oil quenching and tempering at 300℃for 120 min and finally air cooling)display excellent mechanical properties of yield strength of 1572 MPa,ultimate tensile strength of 1847 MPa,elongation of 9.84%,and fracture toughness of 106 MPa m^(1/2),which are counterparts to those of conventional DT300 steel forgings after heat treatment.展开更多
Mental disorders comprise a range of abnormal states that affect an individual's cognition,emotion,behavior,and social functioning,potentially distorting their perception of reality and seriously impacting their d...Mental disorders comprise a range of abnormal states that affect an individual's cognition,emotion,behavior,and social functioning,potentially distorting their perception of reality and seriously impacting their daily life,work,and interpersonal relationships.Mental disorders,including anxiety disorders,depression,schizo-phrenia,and bipolar disorder,impact not only individuals,but also their families and societies at large.The incidence of mental disorders increased by 31.6%between 1990 and 2007,and this trend continued between 2007 and 2017(percentage change:13.5%)[1].In China,the lifetime prevalence of mental disorders is 16.6%and has been reported to exhibit a trend toward increasing over time[2].In terms of the global disease burden,mental disorders were reported to account for 5.3%of total disability-adjusted life years in 2019,underscoring their significant impact on public health[3].展开更多
基金supported by grants from the Natural Science Foundation of Fujian Province(2021J011062)Minjiang Scholars Funding(GY-633Z21067).
文摘This study investigates the bond performance at the interfacial region shared by Ultra-High Performance Concrete(UHPC)and steel tubes through push-out tests.This study examines how changes in steel fiber volumetric ratio and thickness of steel tube influence the bond strength characteristics.The results show that as the enhancement of the steel tube wall thickness,the ultimate bond strength at the interface improves significantly,whereas the initial bond strength exhibits only slight variations.The influence of steel fiber volumetric ratio presents a nonlinear trend,with initial bond strength decreasing at low fiber content and increasing significantly as fiber content rises.Additionally,finite element(FE)simulations were applied to replicate the experimental conditions,and the outcomes showed strong correlation with the experimental data,confirming the exactitude of the FE model in predicting the bond behavior at the UHPC-Steel interface.These findings provide valuable insights for optimizing the design of UHPC-Filled steel tubes in high-performance structure.
基金supported by the National Natural Science Foundation of China(No.52175341)Shandong Provincial Natural Science Foundation(No.ZR2022JQ24)+2 种基金Funding Project of Jinan City's New Twenty Items for Colleges and Universities(No.202333038)Excellent Young Team Project of Central Universities(No.2023QNTD002)Qingdao Key Technology Research and Industrialization Demonstration Project(No.24-1-2-qljh-10-gx).
文摘Poly(vinylidene fluoride)(PVDF)foam has received widespread attention due to its high strength,and excellent combination of flame-retardancy,antibacterial performance,and chemical stability.However,the foaming ability of conventional PvDF is severely limited by its rapid crystallization kinetics and poor melt strength.Although ultra-high molecular weight PVDF(H-PVDF)theoretically offers prolonged melt elasticity favorable for foaming,the extremely high melt viscosity poses substantial processing challenges,and its foaming behavior has remained largely unexplored.To address these issues,this study proposes a novel fabrication strategy combining solvent casting with microcellular foaming to prepare H-PVDF foams.Dynamic mechanical analysis and differential scanning calorimetry reveal that extensive chain entanglements in H-PVDF impose constraints on crystallization and significantly enhance melt strength.By tuning the processing parameters,the distinctive foaming be-havior of H-PVDF under various conditions is systematically elucidated.Remarkably,a record-high expansion ratio of 55.6-fold is achieved,ac-companied by a highly uniform and fine cellular structure.The resulting H-PVDF foams exhibit a low thermal conductivity of 31.8 mW·m^(-1).K^(-1),while retaining excellent compressive strength,flame-retardancy,and hydrophobicity.These outstanding properties highlight the great potential of H-PVDF foams as the thermal insulation materials for applications in aerospace,energy infrastructure,and other extreme environments.
基金supported by the Science and Technology Project of Fire Rescue Bureau of Ministry of Emergency Management,China(No.2022XFZD05)the S&T Program of Hebei,China(No.22375419D).
文摘Ultra-high strength steel(UHSS)fabricated via laser additive manufacturing(LAM)holds significant promise for applications in defense,aerospace,and other high-performance sectors.However,its response to high-impact loading remains insufficiently understood,particularly regarding the influence of energy density on its dynamic mechanical behavior.In this study,scanning electron micro-scopy,electron backscatter diffraction,and image recognition techniques were employed to investigate the microstructural variations of LAM-fabricated UHSS under different energy density conditions.The dynamic mechanical behavior of the material was characterized using a Split Hopkinson Pressure Bar system in combination with high-speed digital image correlation.The study reveals the spatiotemporal evolution of surface strain and crack formation,as well as the underlying dynamic fracture mechanisms.A clear correlation was established between the microstructures formed under varying energy densities and the resulting dynamic mechanical strength of the material.Results demonstrate that optimal material density is achieved at energy densities of 292 and 333 J/mm^(3).In contrast,energy densities exceeding 333 J/mm^(3) induce keyhole defects,compromising structural integrity.Dynamic performance is strongly dependent on material density,with peak impact resistance observed at 292 J/mm^(3)-where strength is 8.4%to 17.6%higher than that at 500 J/mm^(3).At strain rates≥2000 s^(-1),the material reaches its strength limit at approximately 110μs,with the initial crack appearing within 12μs,followed by rapid failure.Conversely,at strain rates≤1500 s^(-1),only microcracks and adiabatic shear bands are detected.A transition in fracture surface morphology from ductile to brittle is observed with increasing strain rate.These findings offer critical insights into optimizing the dynamic mechanical properties of LAM-fabricated UHSS and provide a valuable foundation for its deployment in high-impact environments.
文摘It is well known that transition metal sulfides(TMS)(i.e.,NiS_(2))undergo electrochemical reconstructions to generate highly active Ni_(3)S_(2) during the process of hydrogen evolution reaction(HER)under overpotentials of<500 mV.However,at higher overpotentials,Ni_(3)S_(2) can theoretically be further restructured into Ni and thus form Ni/Ni_(3)S_(2) heterogeneous interface structures,which may provide opportunities to further enhance HER activity of NiS_(2).Here,we selected NiS_(2) as a model electrocatalyst and investigated the influence of the reconstruction results induced from regular to ultrahigh overpotentials on its electrocatalytic hydrogen precipitation performance.The experimental results showed that the most significant enhancement of hydrogen precipitation performance was obtained for the NiS_(2)@CC-900(900 means 900 mV overpotential)sample after the ultra-high overpotential induced reconstruction.Compared with the initial overpotential of 161 mV(10 mA cm^(-2)),the overpotential of the reconstructed sample reduced by 67 mV(42%).The characterization results showed that an ultra-high overpotential of 900 mV induced deep reconstruction of NiS_(2),formed highly reactive Ni/Ni_(3)S_(2) heterogeneous interfaces,which is more conducive to improved HER performance and match well with theoretical calculations results.We demonstrated ultrahigh overpotential was an effective strategy to induce NiS_(2) deeply reconstruction and significantly improve its HER performance,and this strategy was also applicable to CoS_(2) and FeS_(2).This study provides an extremely simple and universal pathway for the reasonable construction of efficient electrocatalysts by induced TMS deeply reconstruction.
文摘Ultra-high dose rate flash radiotherapy(FLASH-RT)has attracted wide attention in the field of radiotherapy in recent years.For FLASH-RT,radiation is delivered at a very high dose rate[usually thousands of times compared with conventional radiotherapy(CONV-RT)]in an extremely short time.This novel irradiation technique shows a protective effect on normal tissues,also known as the flash effect.At the same time,FLASH-RT is comparable to CONV-RT in terms of tumorkilling efficacy.As basic research dedicates to uncover the mechanisms by which FLASH-RT reduces radiation-induced normal tissue damage,clinical trials of FLASH-RT have been gradually conducted worldwide.This article systematically reviews the evidence of the feasibility and safety of FLASH-RT in clinical practice and offers insights into the future translation of this technology in clinic.
基金supported financially by National Key Research and Development Program of China(No.2022YFB3705200)Heilongjiang Province's Key Technology Project:‘Leading the Charge with Open Competition’(No.2023ZXJ04A02)Youth Program of CISRI Funding under Grant(No.S-23T60190B).
文摘The effects of prior austenite and primary carbides on the mechanical properties of a novel 2.5 GPa grade steel were investigated by treating at various solid-solution temperatures.The ultimate tensile strength and Charpy U-notch impact energy initially increased and subsequently decreased as the solid-solution temperature rose,while the yield strength consistently decreased.The size of prior austenite grain and martensite block always increased with rising the solid-solution temperature,and austenite grain growth activation energy is 274,969 J/mol.The growth of prior austenite was restricted by primary carbides M6C and MC.The dissolution of the primary carbides not only enhanced solid-solution strengthening and secondary hardening effects but also increased the volume fraction of retained austenite.The increase in the ultimate tensile strength and Charpy U-notch impact energy was primarily attributed to the dissolution of the primary carbides M6C and MC,while the decrease was due to the increase in the size of prior austenite grain and martensite block.Exceptional combination of strength,ductility and toughness with ultimate tensile strength of 2511 MPa,yield strength of 1920 MPa,elongation of 9.5%,reduction of area of 41%and Charpy U-notch impact energy of 19.5 J was obtained when experimental steel was solid-solution treated at 1020℃.
基金supported by the National Key R&D Program of China(No.2022YFB3203900).
文摘Integrating thick/thin film sensors into component systems has emerged as a prevalent approach for monitoring in extreme environments.However,traditional vapor deposition methods face obstacles,including complex fabrication processes and the degradation of sensitive materials at extremely high temperatures.This work delineates the development of a polysilazane composite dual-layer thick-film Negative Temperature Coefficient(NTC)thermistor characterized by its suitability for extreme temperatures and robust bond strength achieved through an advanced near-net-shape printing methodology.High-temperature resistant La(Ca)CrO_(3)/polysilazane films were printed as the sensitive layer,while a dense layer formed by Cr_(2)O_(3)/polysilazane was used as the protective layer.The bilayer structure resulted in a 2.5-fold increase in adhesion strength compared to the single-layer La(Ca)CrO_(3)/polysilazane films.Experimental results indicate that the dual-layer thick-film NTC thermistor can be operated long-term at 1300℃ with a resistance drift rate of 0.9%/h and survive short-term exposure to temperatures up to 1550℃.As a proof of concept,this work applied 3D printing technology to fabricate a polysilazane composite dual-layer thick-film NTC thermistor on the surface of turbine blades and demonstrated its functionality under flame impingement at nearly 1300℃.Such flexible 3D printing techniques pave the way for a new paradigm in manufacturing sensors capable of withstanding ultra-high temperatures.
基金National Natural Science Foundation of China,Grant/Award Number:81973476Chinese Society of Toxicology,Grant/Award Number:CST2021CT101。
文摘Background:Polygonum multiflorum-induced liver injury(PM-DILI)has significantly hindered its clinical application and development.Methods:This study investigates the variation in content and toxicity of dian-thrones,the toxic components of P.multiflorum,during different processing cycles.We employed the ultra-high-performance liquid chromatography triple quadrupole mass spectrometry method to quantify six dianthrones in raw P.multiflorum and formulations processed with a method called nine cycles of steaming and sunning.Additionally,toxicity assessments were conducted using human normal liver cell line L02 and zebrafish embryos.Results:Results indicate a gradual reduction in dianthrones content with increasing processing cycles.Processed formulations exhibited significantly reduced cytotoxic-ity in L02 cells and hepatotoxicity in zebrafish embryos.Conclusions:Our findings elucidate the relationship between processing cycles and P.multiflorum toxicity,providing theoretical support for its safe use.
基金financially supported by the National Key Research and Development Program of China(No.2016YFB0302300)the China Postdoctoral Science Foundation(No.2019M652883)+1 种基金the Guangdong Basic and Applied Basic Research Foundation(No.2020A1515110467)the financial support from the opening project of Guangdong provincial key laboratory of technique and equipment for macromolecular advanced manufacturing,South China University of Technology,China。
文摘Currently,the enhancement in electromagnetic interference(EMI)performance of polymeric composite generally relies on either improving electrical conductivity(σ)for stronger electromagnetic(EM)reflections or tailoring structure for higher EM resonances.Herein,we proposed a novel technique called cyclic pulsating pressure enhanced segregating structuration(CPP-SS),which can reinforce these two factors simultaneously.The structural information was supplied by optical microscopy(OM)and scanning electron microscopy(SEM),both of which confirmed the formation and evolution of segregate structured ultra-high molecular weight polyethylene(UHMWPE)/graphene composites.Then,the result showed that CPP-SS can significantly improve theσof samples.Ultimately,advanced specific EMI shielding efficiency of 31.1 d B/mm was achieved for UHMWPE/graphene composite at 1-mm thickness and a low graphene loading of 5 wt%.Meanwhile,it also confirmed that the intrinsic disadvantage of poor mechanical properties of conventional segregated structure composites can be surpassed.This work is believed to provide a fundamental understanding of the structural and performance evolutions of segregated structured composites prepared under CPPSS,and to bring us a simple and efficient approach for fabricating high-performance,strong and light-weight polymeric EMI shields.
基金Key Research and Development Program of Hubei Province(2022BCA082 and 2022BCA077).
文摘To achieve higher strength and better durability,ultra-high performance concrete(UHPC)typically employs a relatively small water-binder ratio.However,this generally leads to an undesired increase in the paste viscosity.In this study,the effects of liquid and powder polycarboxylate superplasticizers(PCE)on UHPC are compared and critically discussed.Moreover,the following influential factors are considered:air-entraining agents(AE),slump retaining agents(SA),and defoaming agents(DF)and the resulting flow characteristics,mechanical properties,and hydration properties are evaluated assuming UHPC containing 8‰powder PCE(PCE-based UHPC).It is found that the spread diameter of powder PCE is 5%higher than that of liquid PCE.Among the chemical admixtures studied,AEs have the best effect on improving UHPC workability,while DFs have the worst effect.When the addition of AE and SA is 1.25‰and 14.7%of PCE,paste viscosity reduces by 35%and 19%,respectively compared to the paste with only 8‰PCE.A low AE dosage(1.25‰)decreases compressive strength by 4.1%,while SA(8.1%)increases UHPC compressive strength by 9.1%.Both AE and SA significantly delay the UHPC hydration process,reducing the hydration heat release peaks by 76%and 27%,respectively.
基金the Key Research and Development Program of Hubei Province(2022BCA082 and 2022BCA077).
文摘Due to the low water-cement ratio of ultra-high-performance concrete(UHPC),fluidity and shrinkage cracking are key aspects determining the performance and durability of this type of concrete.In this study,the effects of different types of cementitious materials,chemical shrinkage-reducing agents(SRA)and steel fiber(SF)were assessed.Compared with M2-UHPC and M3-UHPC,M1-UHPC was found to have better fluidity and shrinkage cracking performance.Moreover,different SRA incorporation methods,dosage and different SF types and aspect ratios were implemented.The incorporation of SRA and SF led to a decrease in the fluidity of UHPC.SRA internal content of 1%(NSRA-1%),SRA external content of 1%(WSRA-1%),STS-0.22 and STE-0.7 decreased the fluidity of UHPC by 3.3%,8.3%,9.2%and 25%,respectively.However,SRA and SF improved the UHPC shrinkage cracking performance.NSRA-1%and STE-0.7 reduced the shrinkage value of UHPC by 40%and 60%,respectively,and increased the crack resistance by 338%and 175%,respectively.In addition,the addition of SF was observed to make the microstructure of UHPC more compact,and the compressive strength and flexural strength of 28 d were increased by 26.9%and 19.9%,respectively.
基金financially supported by the National Natural Science Foundation of China (Nos.52271003,52071024,52271003 and 52101188)the Funds for Creative Research Groups of China (No.51921001)+5 种基金the Projects of International Cooperation and Exchanges of NSFC (Nos.51961160729 and 52061135207)111 Project (No.BP0719004)the Program for Changjiang Scholars and Innovative Research Team in University of China (No.IRT_14R05)the Fundamental Research Fund for the Central Universities of Chinathe Project of Science and Technology on Plasma Dynamics Laboratory,Air Force Engineering University,Xi'an,China (No.126142202210206)the State Key Lab for Advanced Metals and Materials (No.2022-Z10)。
文摘Ultra-high temperature ceramics(UHTCs) offer great potential for applications in extreme service environments,such as hypersonic vehicles,rockets and re-entry spacecraft.However,the severe ablation caused by highspeed heat flow scouring and high-temperature oxidation limits the engineering application of UHTCs.In this work,we report a novel high-entropy UHTC(Ti_(0.2)Zr_(0.2)V_(0.2)Nb_(0.2)Cr_(0.2))(C_(0.5)N_(0.5)),which exhibits superior ablation resistance and light weight compared with traditional UHTCs.Specifically,at a temperature of 2650 K,the mass ablation rate of the material was measured as1.025×10^(-2)g·s^(-1),and the density was calculated to be 6.7 g·cm^(-3).The impressive ablation resistance of(Ti_(0.2)Zr_(0.2)V_(0.2)Nb_(0.2)Cr_(0.2))(C_(0.5)N_(0.5)) is attributed to the incorporation of a self-healing mechanism,which is associated with the in-situ formation of a medium-entropy oxide(TiVCr)O_(2) during the ablation process.The mediumentropy oxide can seal pores and cracks to retard oxygen diffusion and prevent the material from fragmentation,thereby resulting in outstanding ablation resistance.
基金Funed by the National Natural Science Foundation of China(No.U21A20149)the Ecological Environment Scientific Research Project of Anhui Province(No.2023hb0014)+2 种基金the Research Reserve of Anhui Jianzhu University(No.2022XMK01)the Excellent Scientific Research and Innovation Team in Colleges and Universities of Anhui Province(No.2022AH010017)Research on the preparation technology of self compacting concrete with strength grade C100.
文摘We developed ultra-high performance concrete(UHPC)incorporating mullite sand and brown corundum sand(BCS),and the quartz sand UHPC was utilized to prepare for comparison.The properties of compressive strength,elastic modulus,ultrasonic pulse velocity,flexural strength,and toughness were investigated.Scanning electron microscopy and nanoindentation were also conducted to reveal the underlying mechanisms affecting macroscopic performance.Due to the superior interface bonding properties between mullite sand and matrix,the compressive strength and flexural toughness of UHPC have been significantly improved.Mullite sand and BCS aggregates have higher stiffness than quartz sand,contributing to the excellent elastic modulus exhibited by UHPC.The stiffness and volume of aggregates have a more significant impact on the elastic modulus of UHPC than interface performance,and the latter contributes more to the strength of UHPC.This study will provide a reference for developing UHPC with superior elastic modulus for structural engineering.
基金financially supported by National Natural Science Foundation of China(Nos.22174059 and 22201128)Hunan Provincial Natural Science Foundation of China(Nos.2022JJ40363,2022JJ40365 and 2022RC1230)+1 种基金the Excellent youth funding of Hunan Provincial Education Department(No.22B0460)China Postdoctoral Science Foundation(No.2022M721542)。
文摘Artificial macrocycle with high binding selectivity in water is often challenging but urgently needed in various research and application areas.Herein,we report a new water-soluble biomimetic tetralactam macrocycle and realize the ultra-high selectivity to nucleosides over corresponding monophosphate nucleotides by rational modification.The introduction of charged groups at the periphery of endofunctionalized cavity makes the selectivity(guanosine to guanosine 5-monophosphate)increase remarkably from 100 to 1119.Based on the ultra-high selectivity of biomimetic tetralactam macrocycle,the sensitive CD73 enzyme activity assay was then achieved through product-selective fluorescence indicator displacement assay.Furthermore,the capability of the proposed method for inhibitor screening was successfully displayed.
基金supported by the Major Program of National Natural Science Foundation of China(No.52293372).
文摘High-density carbon/carbon(C/C)composite plays a critical role in the aerospace industry owing to excellent mechanical properties and resistance to ablation.However,traditional manufacturing relies on pitch precursor and hot isostatic pressure impregnation and carbonization(HIPIC)technology,which is time-consuming and expensive.In this study,we report an innovative method utilizing polyarylacetylene(PAA)resin and ultra-high pressure impregnation and carbonization(UHPIC)technology.The extremely high char yield of PAA resin(85 wt.%)and high isotropic pressure of UHPIC(over 200 MPa)promote the densification of the composite.As a result,we achieve a high-density(1.90 g/cm^(3))C/C composite with a high degree of graphitization(81%).This composite exhibits impressive properties,including flexural strength of 146 MPa,compressive strength of 187 MPa,and thermal conductivity of 147 W/(m K).When exposed to oxyacetylene flame at 3000 K for 100 s,it displays minimal linear ablation,with a rate of 1.27×10^(-2)mm/s.This study demonstrates the exceptional graphitizable characteristic of PAA resin,setting it apart from conventional resins.Our time-saving and cost-effective approach holds significant promise for aerospace applications,particularly in harsh aerodynamic heating environments.
基金funded by the Key R&D Program of Jilin Province(20220201132GX)the Key R&D Program of Hubei Province(2022BAA084)the Open Funds of the State Key Laboratory of Rare Earth Resource Utilization(RERU2023008)。
文摘Ultra-high nickel cobalt-free lithium layered oxides are promising cathode material for lithium-ion batteries(LIBs)because of their relatively high capacity and low cost.Nevertheless,the high nickel content would induce bulk structure degradation and interfacial environment deterioration,and the absence of Co element reduces the lithium diffusion kinetics,severely limiting the performance liberation of this kind of cathodes.Herein,a multifunctional Ti/Zr dual cation co-doping strategy has been employed to improve the lithium storage performance of LiNi_(0.9)Mn_(0.1)O_(2)(NM91)cathode.On the one hand,the Ti/Zr co-doping weakens the Li^(+)/Ni^(2+)mixing through magnetic interactions due to the inexistence of unpaired electrons for Ti^(4+)and Zr^(4+),increasing the lithium diffusion rate and suppressing the harmful coexistence of H1 and H2 phases.On the other hand,they enhance the lattice oxygen stability because of the strong Ti-O and Zr-O bonds,inhibiting the undesired H3 phase transition and lattice oxygen loss,improving the bulk structure and cathode-electrolyte interface stability.As a result,the Ti/Zr co-doped NM91(NMTZ)exhibits a 91.2%capacity retention rate after 100 cycles,while that of NM91 is only82.9%.Also,the NMTZ displays better rate performance than NM91 with output capacities of 115 and93 mA h g^(-1)at a high current density of 5 C,respectively.Moreover,the designed NMTZ could enable the full battery to deliver an energy density up to 263 W h kg^(-1),making the ultra-high nickel cobaltfree lithium layered oxide cathode closer to practical applications.
基金support of this work by National Natural Science Foundation of China(22075031,51673030,51603017 and 51803011)Jilin Provincial Science&Technology Department(20220201105GX)Chang Bai Mountain Scholars Program of Jilin Province.
文摘Achieving high fouling resistance and permeability using membrane separation technology in water treatment processes remains a challenge.In this work,a novel mixed-matrix membrane(MMM)(poly(arylene ether ketone)[PAEK]-containing carboxyl groups[PAEK-COOH]/UiO-66-NH_(2)@graphene oxide[GO])with superb fouling resistance and high permeability was prepared by the nonsolvent-induced phase separation method,by in-situ growth of UiO-66-NH_(2) on the GO layer,and by preparing hydrophilic PAEK-COOH.On the basis of the structure and performance analysis of the MMM,the maximum water flux reached 591.25 L·m^(-2)·h^(-1) for PAEK-COOH/UiO-66-NH_(2)@GO,whereas the retention rate for bovine serum albumin increased from 85.40%to 94.87%.As the loading gradually increased,the hydrophilicity of the MMMs increased,significantly enhancing their fouling resistance.The strongest anti-fouling ability observed was 94.74%,which was 2.02 times greater than that of the pure membrane.At the same time,the MMMs contained internal amide and hydrogen bonds during the preparation process,forming a cross-linked structure,which further enhanced the mechanical strength and chemical stability.In summary,the MMMs with high retention rate,strong permeability,and anti-fouling ability were successfully prepared.
基金funded by SINOPEC Science and Technology Project P18080by National Energy Administration Research and Development Center Project.
文摘An accurate mapping and understanding of remaining oil distribution is very important for water control and stabilize oil production of mature oilfields in ultra-high water-cut stage.Currently,the Tuo-21 Fault Block of the Shengtuo Oilfield has entered the stage of ultra-high water cut(97.2%).Poor adaptability of the well pattern,ineffective water injection cycle and low efficiency of engineering measures(such as workover,re-perforation and utilization of high-capacity pumps)are the significant problems in the ultra-high water-cut reservoir.In order to accurately describe the oil and water flow characteristics,relative permeability curves at high water injection multiple(injected pore volume)and a semiquantitative method is applied to perform fine reservoir simulation of the Sand group 3e7 in the Block.An accurate reservoir model is built and history matching is performed.The distribution characteristics of remaining oil in lateral and vertical directions are quantitatively simulated and analyzed.The results show that the numerical simulation considering relative permeability at high injection multiple can reflect truly the remaining oil distribution characteristics after water flooding in an ultrahigh water-cut stage.The distribution of remaining oil saturation can be mapped more accurately and quantitatively by using the‘four-points and five-types’classification method,providing a basis for potential tapping of various remaining oil types of oil reservoirs in late-stage of development with high water-cut.
基金funded by the Science and Technology Project of Guangdong Province (2020B090923001)Guangdong Basic and Applied Basic Research Foundation (2023A1515010384)The Fundamental Research Funds for the Central Universities (2023ZYGXZR005).
文摘To address the inhomogeneous microstructure and improve the mechanical properties of DT300 ultra-high strength steel specimens fabricated by laser powder bed fusion,different post-heat treatment schedules are performed.With the increase in austenitizing temperature and time,the migration rate of austenite grain boundaries continuously increases with the dissolution of nano-carbides,and the formation of nano-oxides and twin martensite is also inhibited accordingly.The rapid growth in the size of prior austenite grains and martensite laths,as well as the decrease in the content of nano-oxides and twin martensite,led to a rapid decrease in the strength(yield strength and ultimate tensile strength)from HT2 to HTF specimens.The HT1 specimens(austenitizing at 830℃for 30 min,then oil quenching and tempering at 300℃for 120 min and finally air cooling)display excellent mechanical properties of yield strength of 1572 MPa,ultimate tensile strength of 1847 MPa,elongation of 9.84%,and fracture toughness of 106 MPa m^(1/2),which are counterparts to those of conventional DT300 steel forgings after heat treatment.
文摘Mental disorders comprise a range of abnormal states that affect an individual's cognition,emotion,behavior,and social functioning,potentially distorting their perception of reality and seriously impacting their daily life,work,and interpersonal relationships.Mental disorders,including anxiety disorders,depression,schizo-phrenia,and bipolar disorder,impact not only individuals,but also their families and societies at large.The incidence of mental disorders increased by 31.6%between 1990 and 2007,and this trend continued between 2007 and 2017(percentage change:13.5%)[1].In China,the lifetime prevalence of mental disorders is 16.6%and has been reported to exhibit a trend toward increasing over time[2].In terms of the global disease burden,mental disorders were reported to account for 5.3%of total disability-adjusted life years in 2019,underscoring their significant impact on public health[3].
