Burial dissolution is a critical diagenetic process influencing ultra-deep carbonate reservoir development and preservation.Artificial carbonate samples with different internal structures were prepared,and high-temper...Burial dissolution is a critical diagenetic process influencing ultra-deep carbonate reservoir development and preservation.Artificial carbonate samples with different internal structures were prepared,and high-temperature and highpressure dissolution kinetic simulations were conducted.The results demonstrate that the intensity of burial dissolution is controlled by temperature and pressure,while tectonic-fluid activity influences the development pattern of burial dissolution,ultimately determining the direction of its differential modification.Extensive burial dissolution is likely to occur primarily at relatively shallow depths,significantly influencing reservoir formation,preservation,modification,and adjustment.The development of faults facilitates the maintenance of the intensity of burial dissolution.The maximum intensity of burial dissolution occurs at the tips and overlap zones of faults and intersections of multiple faults.The larger the scale of the faults,the more conducive it is to the development of burial dissolution.Burial dissolution fosters the formation of fault networks characterized by enhanced reservoir capacity and permeability.Burial dissolution controlled by episodic tectonic-fluid activity is a plausible explanation for forming the Tarim Basin's ultra-deep fault-controlled“stringbead-like”reservoirs.展开更多
High pressure die casting(HPDC)AlSi10Mn Mg alloy castings are widely used in the automobile industry.Mg can optimize the mechanical properties of castings through heat treatment,while the release of thermal stress aro...High pressure die casting(HPDC)AlSi10Mn Mg alloy castings are widely used in the automobile industry.Mg can optimize the mechanical properties of castings through heat treatment,while the release of thermal stress arouses the deformation of large integrated die-castings.Herein,the development of non-heat treatment Al alloys is becoming the hot topic.In addition,HPDC contains externally solidified crystals(ESCs),which are detrimental to the mechanical properties of castings.To achieve high strength and toughness of non-heat treatment die-casting Al-Si alloy,we used AlSi9Mn alloy as matrix with the introduction of Zr,Ti,Nb,and Ce.Their influences on ESCs and mechanical properties were systematically investigated through three-dimensional reconstruction and thermodynamic simulation.Our results reveal that the addition of Ti increased ESCs'size and porosity,while the introduction of Nb refined ESCs and decreased porosity.Meanwhile,large-sized Al_3(Zr,Ti)phases formed and degraded the mechanical properties.Subsequent introduction of Ce resulted in the poisoning effect and reduced mechanical properties.展开更多
Degradable metals,represented by magnesium and magnesium alloys,have attracted significant attention as fracture internal fixation and bone defect repairing materials due to their good biocompatibility,suitable elasti...Degradable metals,represented by magnesium and magnesium alloys,have attracted significant attention as fracture internal fixation and bone defect repairing materials due to their good biocompatibility,suitable elastic modulus and degradable properties.The Mg-3Zn-1Ca-0.5Sr(wt%)alloy is considered a competitor in the biomaterial field thanks to its unique composition of essential nutrients and excellent mechanical properties.However,the presence of coarse second-phase particles in the alloy accelerates its degradation rate and causes excessive gas formation during implantation,which restricts the alloy's potential for clinical device applications.In order to further optimize the properties of the alloy,extrusion combined with high-pressure torsion(HPT)was adopted for deformation processing.The results show that by optimizing the material processing means,the grain can be refined and broken,and the second-phase distribution can be improved,thus improving the microstructure,mechanical properties,and corrosion resistance of the alloy.After 15 cycles of HPT processing,the grains of the alloy are significantly refined to the nanometer scale,reaching approximately 98 nm.Additionally,the second-phase distribution is greatly improved,transforming the original streamlined structure into a more dispersed distribution.This change in microstructure leads to a significant strengthening effect on the alloy,with a noticeable increase in hardness from 60.3 HV in the as-extruded state to 98.5 HV.展开更多
A rotary sealing device that automatically compensates for wear is designed to address the issues of easy wear and the short service life of the rotary sealing device with automatic wear compensation in mining machine...A rotary sealing device that automatically compensates for wear is designed to address the issues of easy wear and the short service life of the rotary sealing device with automatic wear compensation in mining machinery.After the end face of the guide sleeve wears out,it still tightly adheres to the sealing valve seat under the pressure difference,achieving automatic wear compensation.Based on fluid-solid coupling technology,the structural strength of the rotary sealing device was checked.The influence of factors on the sealing performance of rotary sealing devices was studied using the control variable method.The results show that as the pressure of water increases,the leakage rate of the sealing device decreases,and after 30 MPa,the leakage rate is almost 0 mL/h.The temperature of the rotating sealing device increases with the increase of rotation speed or pressure,and the temperature is more affected by the rotation speed factor.The frictional torque increases with increasing pressure and is independent of rotational speed.Comprehensive analysis shows that the wear resistance and reliability level of the sealing guide sleeve material is PVDF>PEEK>PE>PA.This study designs a high-pressure automatic compensation wear rotary sealing device and selects the optimal sealing material,providing technical support for the application of high-pressure water jet in mining machinery.展开更多
The utilization of ironsand for preparing oxidized pellets poses challenges,including slow oxidation and low consolidation strength.The effects and function mechanisms of high-pressure grinding roll(HPGR)pretreatment ...The utilization of ironsand for preparing oxidized pellets poses challenges,including slow oxidation and low consolidation strength.The effects and function mechanisms of high-pressure grinding roll(HPGR)pretreatment on the oxidation and consolidation of ironsand pellets were investigated,and the energy utilization efficiency of HPGR with different roller pressure intensities was evaluated.The results indicate that HPGR pretreatment at 8 MPa improves the ironsand properties,with the specific surface area increasing by 740 cm^(2) g^(-1) and mechanical energy storage increasing by 2.5 kJ mol^(-1),which is conducive to oxidation and crystalline connection of particles.As roller pressure intensity increases to 16 MPa,more mechanical energy of HPGR is applied for crystal activation,with mechanical energy storage further rising by 18.1 kJ mol^(-1).The apparent activation energy for pellet oxidation initially decreases and then increases,reaching a minimum at 12 MPa.Simultaneously,the roasted pellets porosity decreases by 2.8%,while the compressive strength increases by 789 N.At higher roller pressure intensity,the densely connected structure between particles impedes gas diffusion within the pellets,diminishing the beneficial effects of HPGR on pellet oxidation.Moreover,excessive roller pressure intensity decreases the HPGR energy utilization efficiency.The optimal HPGR roller pressure intensity for ironsand is 12 MPa,at which the specific surface area increases by 790 cm^(2) g^(-1),mechanical energy storage increases by 10.6 kJ mol^(-1),the compressive strength of roasted pellets rises to 2816 N,and the appropriate preheating and roasting temperatures decrease by 250 and 125°C,respectively.展开更多
The Suizhou meteorite is a heavily shock-met-amorphosed L6 chondrite which contains thin shock melt veins.So far,26 high-pressure phases have been identified from the meteorite.Among the high-pressure phases,ten of th...The Suizhou meteorite is a heavily shock-met-amorphosed L6 chondrite which contains thin shock melt veins.So far,26 high-pressure phases have been identified from the meteorite.Among the high-pressure phases,ten of them were approved as new minerals which include tuite,xieite,wangdaodeite,chenmingite,hemleyite,poirierite,asimowite,hiroseite,elgoresyite,and ohtaniite,by the Commission on New Minerals,Nomenclature and Classification of the International Mineralogical Association.Other high-pressure phases identified from the meteorite are ahrensite,akimotoite,bridgmanite,lingunite,magnesiowüstite,majorite,majorite-pyrope_(ss),maskelynite,riesite,ringwoodite,wadsleyite,and 5 other phases including phase A,vitrified phase B and phase C,phase D(Ca-rich majorite),and partly inverted ringwoodite.The occurrence and abundance of high-pressure phases makes this meteorite the one with the richest variety of high-pressure minerals to date.展开更多
The pore structure of rocks significantly influences the porosity and permeability of reservoirs and the migration ability of oil and gas,and being the key task on the development of volcanic gas reservoirs.Nine volca...The pore structure of rocks significantly influences the porosity and permeability of reservoirs and the migration ability of oil and gas,and being the key task on the development of volcanic gas reservoirs.Nine volcanic rock samples from the Yingcheng Formation and Huoshiling Formation in the Longfengshan area of the Changling Fault Depression in the Songliao Basin were selected for this study.The pore structures of the volcanic rocks in the study area were investigated using high-pressure mercury injection,X-ray diffraction combined with fractal theory.The relationships between the fractal dimension and physical properties characteristics,pore structure parameters,and mineral content were analyzed to provide guidance for the development of volcanic rock gas reservoirs.The results show that the reservoir can be divided into 3 types(I,II,and III)based on the shape of the capillary pressure curve,and the physical properties deteriorate successively.Different types of reservoirs exhibit different fractal characteristics.For typesⅠ,ⅡandⅢ,the average total fractal dimensions were 2.3418,2.6850,and 2.9203,respectively.The larger the fractal dimension,the stronger the heterogeneity of reservoir.A small number of macro-pores primarily contributed to permeability.The fractal dimension was negatively correlated with porosity and permeability.The fractal dimension of the rock was strongly correlated with quartz and feldspar contents,and the mineral composition and content are closely related to the pore evolution of the reservoir,which are the internal factors affecting the fractal dimension of volcanic rock.展开更多
The 304 austenitic stainless steel was processed by high-pressure torsion(HPT)at room temperature with 10,20,and 30 rotations under a pressure of 3 GPa and a rotation speed of 1 r/min.The phase transformation and micr...The 304 austenitic stainless steel was processed by high-pressure torsion(HPT)at room temperature with 10,20,and 30 rotations under a pressure of 3 GPa and a rotation speed of 1 r/min.The phase transformation and microstructural evolution of 304 stainless steel after HPT were investigated by X-ray diffraction(XRD)analysis,electron backscatter diffraction(EBSD)analysis,transmission electron microscopy(TEM),nanoindentation test and differential scanning calorimetry(DSC)analysis.The experimental results show that HPT causes elongated nanocrystalline grains of 25 nm width along the torsion direction.After 10 turns of HPT,the deformation-induced martensitic transformation is completed and the hardness increases from 3 GPa to 8.5 GPa at the edge of the disc.However,a local reverse phase transformation from martensite to austenite is observed in the peripheral regions of the sample after 30 turns of HPT,leading to a higher volume fraction of austenite,and the hardness of the sample also decreases accordingly.展开更多
Achieving optimal mechanical performance in high-pressure die-cast(HPDC)Mg-based alloys through experimental methods is both costly and time-intensive due to significant variations in composition.This study leverages ...Achieving optimal mechanical performance in high-pressure die-cast(HPDC)Mg-based alloys through experimental methods is both costly and time-intensive due to significant variations in composition.This study leverages machine learning(ML)techniques to accelerate the development of high-performance Mg-based alloys.Data on alloy composition and mechanical properties were collected from literature sources,focusing on HPDC Mg-based alloys.Six ML models—extra trees,CatBoost,k-nearest neighbors,random forest,gradient boosting,and decision tree—were trained to predict mechanical behavior.Cat Boost yielded the highest prediction accuracy with R^(2) scores of 0.95 for ultimate tensile strength(UTS)and 0.92 for yield strength(YS).Further validation using published datasets reaffirmed its reliability,demonstrating R^(2) values of 0.956(UTS)and 0.936(YS),MAE of 1%and 2.8%,and RMSE of 1%and 3.5%,respectively.Among these,the CatBoost model demonstrated the highest predictive accuracy,outperforming other ML techniques across multiple optimization metrics.展开更多
Al_(65)Cu_(20)Fe_(15)bulk is synthesized with the high-pressure synthesis(HPS)method.Various analytical techniques,such as single crystal x-ray diffraction(SXRD),scanning electron microscopy equipped with energy-dispe...Al_(65)Cu_(20)Fe_(15)bulk is synthesized with the high-pressure synthesis(HPS)method.Various analytical techniques,such as single crystal x-ray diffraction(SXRD),scanning electron microscopy equipped with energy-dispersive x-ray spectroscopy,and transmission electron microscopy,are employed to characterize the sintered bulk and confirmed its quasicrystalline structure.The electrical resistivity of the HPS quasicrystal specimen is measured from 2 K to 300 K,revealing a significantly elevated value in comparison to samples prepared via alternative methods.Nanoindentation testing demonstrates exceptional hardness and elastic modulus of our Al_(65)Cu_(20)Fe_(15)quasicrystal,consistent with existing results.The ratio of hardness to elastic modulus further highlight the potential superior wear resistance of the Al_(65)Cu_(20)Fe_(15)quasicrystal.Differential scanning calorimetry measurement conducted on the HPS Al_(65)Cu_(20)Fe_(15)quasicrystals reveal a high melting point of 877℃.展开更多
Perovskite oxynitrides AB(N,O)_(3), a crucial class in materials science, have attracted much attention. By precisely controlling A-and B-site ions and tuning the N/O ratio, new materials with exotic charge states and...Perovskite oxynitrides AB(N,O)_(3), a crucial class in materials science, have attracted much attention. By precisely controlling A-and B-site ions and tuning the N/O ratio, new materials with exotic charge states and intriguing electronic behaviors can be designed and synthesized. In this work, a novel oxynitride perovskite, CeNbO_(2)N, was prepared under high-temperature and high-pressure conditions. The compound crystallizes in an orthorhombic perovskite structure in Pnma symmetry with disordered N/O distribution. The x-ray absorption spectroscopy confirms the presence of a Nb^(4+) state with 4d^(1) electronic configuration in CeNbO_(2)N. As a result, the resistivity of CeNbO_(2)N is sharply reduced compared to its counterpart CeTa^(5+)ON_(2) and other Nb^(5+) compounds. No long-range spin order is found to occur with the temperature down to 2 K in CeNbO_(2)N, while a remarkable negative magnetoresistance effect shows up at lower temperatures, probably due to the magnetic scattering arising from short-range spin correlations.展开更多
Iron nitride(Fe_(x)N_y) is a promising candidate for the next generation of ferromagnetic materials. However, synthesizing high-quality bulk iron nitride with tuned structure and magnetic properties remains a challeng...Iron nitride(Fe_(x)N_y) is a promising candidate for the next generation of ferromagnetic materials. However, synthesizing high-quality bulk iron nitride with tuned structure and magnetic properties remains a challenge. Currently, experimental and theoretical results regarding the magnetic property of iron nitrides remain controversial. With the recent advancements in high-pressure technology, new synthetic pathways to iron nitrides have been proposed. High-pressure synthesis technology provides multidimensional possibilities for tuning the structure and magnetic properties of iron nitrides. This review summarizes recent progress in high-pressure synthesis of iron nitrides, especially the high-pressure solid-state metathesis reaction synthesis(HSM). We have summarized the reaction characteristics of HSM. The HSM reaction exhibits vector synthesis characteristics and promotes nitrogen disorder diffusion at high temperature. Due to this, the HSM reaction can achieve the synthesis of multinary iron-based metal nitrides and regulate the local magnetic moments. It serves as a powerful means for tuning the structure and magnetic properties of iron nitrides. Taking advantage of neutron diffraction in characterizing local magnetic moment and nitrogen disorder in iron nitrides, the relationship between iron local magnetic moment and nitrogen content has been elucidated. Moreover, the development of high-pressure in-situ imaging technology based on large-volume press allows the real-time observation of HSM reaction process. In this review, we also report our latest experiments on neutron diffraction and high-pressure in-situ image for the study of iron nitrides.展开更多
In order to achieve combined mechanical and electrical properties,multi-walled carbon nanotubes(MWCNTs)reinforced Cu/Ti_(3)SiC_(2)/C nanocomposites were further processed by high-pressure torsion(HPT).The maximum micr...In order to achieve combined mechanical and electrical properties,multi-walled carbon nanotubes(MWCNTs)reinforced Cu/Ti_(3)SiC_(2)/C nanocomposites were further processed by high-pressure torsion(HPT).The maximum microhardness values of central and edge from the composites with 1 wt.%MWCNTs reached HV 130.0 and HV 363.5,which were 43.9%and 39.5%higher than those of the original samples,respectively.With the same content of MWCNTs,its electrical conductivity achieved 3.42×10^(7) S/m,which was increased by 78.1%compared with that of original samples.The synergistic improvement of mechanical and electrical properties is attributed to the obtained microstructure with increased homogenization and refinement,as well as improved interfacial bonding and reduced porosity.The strengthening mechanisms include dispersion and refinement strengthening for mechanical properties,as well as reduced electron scattering for electrical properties.展开更多
The increasingly stringent emission regulations and fuel consumption requirements have elevated the demands of internal combustion engines with higher fuel efficiency and lower emissions.It has been widely demonstrate...The increasingly stringent emission regulations and fuel consumption requirements have elevated the demands of internal combustion engines with higher fuel efficiency and lower emissions.It has been widely demonstrated that fash boiling spray can generate shorter and wider spray with improved atomization and evaporation to promote a better air-fuel mixing process.In this study,macroscopic(far-field)spray morphologies and primary breakup(near-field)characteristics of a two-hole gasoline direct injection injector are investigated under non-flash boiling and flash boiling conditions.High speed macroscopic and microscopic imaging was used to capture the overall spray structure and near-field characteristics,respectively.N-Hexane is used as the test fuel with the injection pressure ranging from 10 MPa up to 40 MPa.For sub-cooled liquid fuel sprays,increasing fuel pressure contributes to enhanced fuel atomization and evaporation.Evident collapses occurred under fare flash boiling conditions,and higher injection pressure weakened this phenomenon since the spray cone angle decreased due to a higher injection velocity.展开更多
This study investigated the leaching of scandium from a Sc-bearing silicate ore.The Sc concentrate obtained by beneficiation pre-enrichment has 1.03×10^(−4) wt%Sc and 14.66 wt%Fe.The main Sc-bearing minerals are ...This study investigated the leaching of scandium from a Sc-bearing silicate ore.The Sc concentrate obtained by beneficiation pre-enrichment has 1.03×10^(−4) wt%Sc and 14.66 wt%Fe.The main Sc-bearing minerals are limonite,chlorite,sericite,and hornblende,in the form of isomorphism.High-pressure leaching(HPL)with sulfuric acid(98 wt%)and NaF was used to dispose this samples.The Sc leaching efficiency of 91.82%was obtained under the optimum conditions,which are pressure of 5.0×10^(5) Pa,A/O value of 1.1,L/S value of 1.8,NaF dosage of 2 wt%,at 130℃ for 6 h.The X-ray diffraction(XRD)and scanning electron microscopy(SEM)results show that the residue is mainly quartz phase in the multihole shape.Compared with ordinary leaching for silicate,high-pressure leaching has significant advantages in saving acid and energy consumption.展开更多
The magnetic properties and magnetic phase transition critical behavior of Gd_(3)Ga_5O_(12)single crystals subjected to high-pressure heat treatment were investigated.The results show that high-pressure heat treatment...The magnetic properties and magnetic phase transition critical behavior of Gd_(3)Ga_5O_(12)single crystals subjected to high-pressure heat treatment were investigated.The results show that high-pressure heat treatment reduces the Curie temperature and magnetization of the sample.Under a magnetic field change of 5 T,the maximum isothermal magnetic entropy of the sample is approximately 19.73 J/(kg·K).High-pressure heat treatment increases the phase transition temperature range and leads to an increase in the magnetic refrigeration power.Both Gd_(3)Ga_(5)O_(12)single crystals and the high-pressure heat-treated sample undergo a second-order phase transition.The critical behavior of the samples aligns with the mean field model acquired via critical model fitting.This indicates that the samples exhibit long-range exchange interactions in the system near the Curie temperature.Thus,this material can be used as a magnetic refrigerant for low-temperature applications.展开更多
To improve the comprehensive mechanical properties of Al-Si-Cu alloy,it was treated by a high-pressure torsion process,and the effect of the deformation degree on the microstructure and properties of the Al-Si-Cu allo...To improve the comprehensive mechanical properties of Al-Si-Cu alloy,it was treated by a high-pressure torsion process,and the effect of the deformation degree on the microstructure and properties of the Al-Si-Cu alloy was studied.The results show that the reinforcements(β-Si andθ-CuAl_(2)phases)of the Al-Si-Cu alloy are dispersed in theα-Al matrix phase with finer phase size after the treatment.The processed samples exhibit grain sizes in the submicron or even nanometer range,which effectively improves the mechanical properties of the material.The hardness and strength of the deformed alloy are both significantly raised to 268 HV and 390.04 MPa by 10 turns HPT process,and the fracture morphology shows that the material gradually transits from brittle to plastic before and after deformation.The elements interdiffusion at the interface between the phases has also been effectively enhanced.In addition,it is found that the severe plastic deformation at room temperature induces a ternary eutectic reaction,resulting in the formation of ternary Al+Si+CuAl_(2)eutectic.展开更多
There are various issues for CO_(2)flooding and storage in Shengli Oilfield,which are characterized by low light hydrocarbon content of oil and high miscible pressure,strong reservoir heterogeneity and low sweep effic...There are various issues for CO_(2)flooding and storage in Shengli Oilfield,which are characterized by low light hydrocarbon content of oil and high miscible pressure,strong reservoir heterogeneity and low sweep efficiency,gas channeling and difficult whole-process control.Through laboratory experiments,technical research and field practice,the theory and technology of CO_(2)high pressure miscible flooding and storage are established.By increasing the formation pressure to 1.2 times the minimum miscible pressure,the miscibility of the medium-heavy components can be improved,the production percentage of oil in small pores can be increased,the displacing front developed evenly,and the swept volume expanded.Rapid high-pressure miscibility is realized through advanced pressure flooding and energy replenishment,and technologies of cascade water-alternating-gas(WAG),injection and production coupling and multistage chemical plugging are used for dynamic control of flow resistance,so as to obtain the optimum of oil recovery and CO_(2)storage factor.The research results have been applied to the Gao89-Fan142 in carbon capture,utilization and storage(CCUS)demonstration site,where the daily oil production of the block has increased from 254.6 t to 358.2 t,and the recovery degree is expected to increase by 11.6 percentage points in 15 years,providing theoretical and technical support for the large-scale development of CCUS.展开更多
Repairs of corroded high-pressure pipelines are essential for fluids transportation under high pressure.One of the methods used in their repairs is the use of layered composites.The composite used must have the necess...Repairs of corroded high-pressure pipelines are essential for fluids transportation under high pressure.One of the methods used in their repairs is the use of layered composites.The composite used must have the necessary strength.Therefore,the experiments and analytical solutions presented in this paper are performed according to the relevant standards and codes,including ASME PCC-2,ASME B31.8S,ASME B31.4,ISO 24817 and ASME B31.G.In addition,the experimental tests are replicated numerically using the finite element method.Setting the strain gauges at different distances from the defect location,can reduce the nonlinear effects,deformation,and fluctuations due to the high pressure.The direct relationship between the depth of an axial defect and the stress concentration is observed at the inner side edges of the defect.Composite reparation reduces the non-linearities related to the sharp variation of the geometry and a more reliable numerical simulation could be performed.展开更多
The Mg–Zn–Gd alloy with quasicrystal icosahedral phase was processed by high-pressure torsion (HPT). The effect of bimodal I-phase on the dynamic recrystallization was analyzed by transmission electron microscopy. T...The Mg–Zn–Gd alloy with quasicrystal icosahedral phase was processed by high-pressure torsion (HPT). The effect of bimodal I-phase on the dynamic recrystallization was analyzed by transmission electron microscopy. The results showed that the block I-phase can stimulate obvious particle-stimulated nucleation and dynamic recrystallization (DRX) grains were preferentially formed after HPT for 5 turns, while the granular I-phase only promoted the generation of sub-grains. The orientation relationship was determined as twofold//[1210] and fivefold//(0002)_(Mg). Moreover, after HPT for 9 turns, the DRX grains induced by block I-phase appeared to grow up and coarsened. Compared with block I-phase, the grains induced by granular I-phase presented much smaller size and distributed more homogeneous due to the strong pinning effect.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.U21B2062)supported by the Key Laboratory for Carbonate Reservoirs of China National Petroleum Corporation。
文摘Burial dissolution is a critical diagenetic process influencing ultra-deep carbonate reservoir development and preservation.Artificial carbonate samples with different internal structures were prepared,and high-temperature and highpressure dissolution kinetic simulations were conducted.The results demonstrate that the intensity of burial dissolution is controlled by temperature and pressure,while tectonic-fluid activity influences the development pattern of burial dissolution,ultimately determining the direction of its differential modification.Extensive burial dissolution is likely to occur primarily at relatively shallow depths,significantly influencing reservoir formation,preservation,modification,and adjustment.The development of faults facilitates the maintenance of the intensity of burial dissolution.The maximum intensity of burial dissolution occurs at the tips and overlap zones of faults and intersections of multiple faults.The larger the scale of the faults,the more conducive it is to the development of burial dissolution.Burial dissolution fosters the formation of fault networks characterized by enhanced reservoir capacity and permeability.Burial dissolution controlled by episodic tectonic-fluid activity is a plausible explanation for forming the Tarim Basin's ultra-deep fault-controlled“stringbead-like”reservoirs.
基金financially supported by the National Natural Science Foundation of China(Nos.52175284 and 52474396)the National Key Research and Development Program of China(No.2022YFB3404201)。
文摘High pressure die casting(HPDC)AlSi10Mn Mg alloy castings are widely used in the automobile industry.Mg can optimize the mechanical properties of castings through heat treatment,while the release of thermal stress arouses the deformation of large integrated die-castings.Herein,the development of non-heat treatment Al alloys is becoming the hot topic.In addition,HPDC contains externally solidified crystals(ESCs),which are detrimental to the mechanical properties of castings.To achieve high strength and toughness of non-heat treatment die-casting Al-Si alloy,we used AlSi9Mn alloy as matrix with the introduction of Zr,Ti,Nb,and Ce.Their influences on ESCs and mechanical properties were systematically investigated through three-dimensional reconstruction and thermodynamic simulation.Our results reveal that the addition of Ti increased ESCs'size and porosity,while the introduction of Nb refined ESCs and decreased porosity.Meanwhile,large-sized Al_3(Zr,Ti)phases formed and degraded the mechanical properties.Subsequent introduction of Ce resulted in the poisoning effect and reduced mechanical properties.
基金National Key Research and Development Program of China(2021YFB3701004)。
文摘Degradable metals,represented by magnesium and magnesium alloys,have attracted significant attention as fracture internal fixation and bone defect repairing materials due to their good biocompatibility,suitable elastic modulus and degradable properties.The Mg-3Zn-1Ca-0.5Sr(wt%)alloy is considered a competitor in the biomaterial field thanks to its unique composition of essential nutrients and excellent mechanical properties.However,the presence of coarse second-phase particles in the alloy accelerates its degradation rate and causes excessive gas formation during implantation,which restricts the alloy's potential for clinical device applications.In order to further optimize the properties of the alloy,extrusion combined with high-pressure torsion(HPT)was adopted for deformation processing.The results show that by optimizing the material processing means,the grain can be refined and broken,and the second-phase distribution can be improved,thus improving the microstructure,mechanical properties,and corrosion resistance of the alloy.After 15 cycles of HPT processing,the grains of the alloy are significantly refined to the nanometer scale,reaching approximately 98 nm.Additionally,the second-phase distribution is greatly improved,transforming the original streamlined structure into a more dispersed distribution.This change in microstructure leads to a significant strengthening effect on the alloy,with a noticeable increase in hardness from 60.3 HV in the as-extruded state to 98.5 HV.
基金Supported by Jiangsu Provincial Natural Science Foundation(Grant No.BK20231497)Jiangsu Provincial Post graduate Research&Practice Innovation Program(Grant No.KYCX25_2982)+3 种基金China University of Mining and Technology Graduate Innovation Program(Grant No.2025WLKXJ094)National Natural Science Foundation of China(Grant No.51975573)National Key R&D Program of China(Grant No.2022YFC2905600)Priority Academic Program Development of Jiangsu Higher Education Institute of China.
文摘A rotary sealing device that automatically compensates for wear is designed to address the issues of easy wear and the short service life of the rotary sealing device with automatic wear compensation in mining machinery.After the end face of the guide sleeve wears out,it still tightly adheres to the sealing valve seat under the pressure difference,achieving automatic wear compensation.Based on fluid-solid coupling technology,the structural strength of the rotary sealing device was checked.The influence of factors on the sealing performance of rotary sealing devices was studied using the control variable method.The results show that as the pressure of water increases,the leakage rate of the sealing device decreases,and after 30 MPa,the leakage rate is almost 0 mL/h.The temperature of the rotating sealing device increases with the increase of rotation speed or pressure,and the temperature is more affected by the rotation speed factor.The frictional torque increases with increasing pressure and is independent of rotational speed.Comprehensive analysis shows that the wear resistance and reliability level of the sealing guide sleeve material is PVDF>PEEK>PE>PA.This study designs a high-pressure automatic compensation wear rotary sealing device and selects the optimal sealing material,providing technical support for the application of high-pressure water jet in mining machinery.
基金financially supported by the General Program of National Natural Science Foundation of China(No.52174330)Hunan Provincial Innovation Foundation for Postgraduate(No.QL20220069)Postgraduate Innovative Project of Central South University(No.1053320214756).
文摘The utilization of ironsand for preparing oxidized pellets poses challenges,including slow oxidation and low consolidation strength.The effects and function mechanisms of high-pressure grinding roll(HPGR)pretreatment on the oxidation and consolidation of ironsand pellets were investigated,and the energy utilization efficiency of HPGR with different roller pressure intensities was evaluated.The results indicate that HPGR pretreatment at 8 MPa improves the ironsand properties,with the specific surface area increasing by 740 cm^(2) g^(-1) and mechanical energy storage increasing by 2.5 kJ mol^(-1),which is conducive to oxidation and crystalline connection of particles.As roller pressure intensity increases to 16 MPa,more mechanical energy of HPGR is applied for crystal activation,with mechanical energy storage further rising by 18.1 kJ mol^(-1).The apparent activation energy for pellet oxidation initially decreases and then increases,reaching a minimum at 12 MPa.Simultaneously,the roasted pellets porosity decreases by 2.8%,while the compressive strength increases by 789 N.At higher roller pressure intensity,the densely connected structure between particles impedes gas diffusion within the pellets,diminishing the beneficial effects of HPGR on pellet oxidation.Moreover,excessive roller pressure intensity decreases the HPGR energy utilization efficiency.The optimal HPGR roller pressure intensity for ironsand is 12 MPa,at which the specific surface area increases by 790 cm^(2) g^(-1),mechanical energy storage increases by 10.6 kJ mol^(-1),the compressive strength of roasted pellets rises to 2816 N,and the appropriate preheating and roasting temperatures decrease by 250 and 125°C,respectively.
基金Science and Technology Planning Project of Guangdong Province(2023B1212060048).
文摘The Suizhou meteorite is a heavily shock-met-amorphosed L6 chondrite which contains thin shock melt veins.So far,26 high-pressure phases have been identified from the meteorite.Among the high-pressure phases,ten of them were approved as new minerals which include tuite,xieite,wangdaodeite,chenmingite,hemleyite,poirierite,asimowite,hiroseite,elgoresyite,and ohtaniite,by the Commission on New Minerals,Nomenclature and Classification of the International Mineralogical Association.Other high-pressure phases identified from the meteorite are ahrensite,akimotoite,bridgmanite,lingunite,magnesiowüstite,majorite,majorite-pyrope_(ss),maskelynite,riesite,ringwoodite,wadsleyite,and 5 other phases including phase A,vitrified phase B and phase C,phase D(Ca-rich majorite),and partly inverted ringwoodite.The occurrence and abundance of high-pressure phases makes this meteorite the one with the richest variety of high-pressure minerals to date.
基金Supported by Key Scientific and Technological Projects of Sinopec(No.P21104-2).
文摘The pore structure of rocks significantly influences the porosity and permeability of reservoirs and the migration ability of oil and gas,and being the key task on the development of volcanic gas reservoirs.Nine volcanic rock samples from the Yingcheng Formation and Huoshiling Formation in the Longfengshan area of the Changling Fault Depression in the Songliao Basin were selected for this study.The pore structures of the volcanic rocks in the study area were investigated using high-pressure mercury injection,X-ray diffraction combined with fractal theory.The relationships between the fractal dimension and physical properties characteristics,pore structure parameters,and mineral content were analyzed to provide guidance for the development of volcanic rock gas reservoirs.The results show that the reservoir can be divided into 3 types(I,II,and III)based on the shape of the capillary pressure curve,and the physical properties deteriorate successively.Different types of reservoirs exhibit different fractal characteristics.For typesⅠ,ⅡandⅢ,the average total fractal dimensions were 2.3418,2.6850,and 2.9203,respectively.The larger the fractal dimension,the stronger the heterogeneity of reservoir.A small number of macro-pores primarily contributed to permeability.The fractal dimension was negatively correlated with porosity and permeability.The fractal dimension of the rock was strongly correlated with quartz and feldspar contents,and the mineral composition and content are closely related to the pore evolution of the reservoir,which are the internal factors affecting the fractal dimension of volcanic rock.
基金Funded by the National Natural Science Foundation of China(No.51905215)the Postgraduate Research&Practice Innovation Program of Jiangsu Province(No.SJCX231233)。
文摘The 304 austenitic stainless steel was processed by high-pressure torsion(HPT)at room temperature with 10,20,and 30 rotations under a pressure of 3 GPa and a rotation speed of 1 r/min.The phase transformation and microstructural evolution of 304 stainless steel after HPT were investigated by X-ray diffraction(XRD)analysis,electron backscatter diffraction(EBSD)analysis,transmission electron microscopy(TEM),nanoindentation test and differential scanning calorimetry(DSC)analysis.The experimental results show that HPT causes elongated nanocrystalline grains of 25 nm width along the torsion direction.After 10 turns of HPT,the deformation-induced martensitic transformation is completed and the hardness increases from 3 GPa to 8.5 GPa at the edge of the disc.However,a local reverse phase transformation from martensite to austenite is observed in the peripheral regions of the sample after 30 turns of HPT,leading to a higher volume fraction of austenite,and the hardness of the sample also decreases accordingly.
基金supported by Basic Science Research Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Education(2021R1A6A1A10044950)。
文摘Achieving optimal mechanical performance in high-pressure die-cast(HPDC)Mg-based alloys through experimental methods is both costly and time-intensive due to significant variations in composition.This study leverages machine learning(ML)techniques to accelerate the development of high-performance Mg-based alloys.Data on alloy composition and mechanical properties were collected from literature sources,focusing on HPDC Mg-based alloys.Six ML models—extra trees,CatBoost,k-nearest neighbors,random forest,gradient boosting,and decision tree—were trained to predict mechanical behavior.Cat Boost yielded the highest prediction accuracy with R^(2) scores of 0.95 for ultimate tensile strength(UTS)and 0.92 for yield strength(YS).Further validation using published datasets reaffirmed its reliability,demonstrating R^(2) values of 0.956(UTS)and 0.936(YS),MAE of 1%and 2.8%,and RMSE of 1%and 3.5%,respectively.Among these,the CatBoost model demonstrated the highest predictive accuracy,outperforming other ML techniques across multiple optimization metrics.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.52173231 and 51925105)the Natural Science Foundation of Hebei Province,China(Grant No.E2022203182)+1 种基金The Innovation Ability Promotion Project of Hebei supported by Hebei Key Laboratory for Optimizing Metal Product Technology and Performance(Grant No.22567609H)supported by the grants from Slovak National Agencies(Grant Nos.VEGA 2/0144/21,APVV19-0369,and APVV-20-0124)。
文摘Al_(65)Cu_(20)Fe_(15)bulk is synthesized with the high-pressure synthesis(HPS)method.Various analytical techniques,such as single crystal x-ray diffraction(SXRD),scanning electron microscopy equipped with energy-dispersive x-ray spectroscopy,and transmission electron microscopy,are employed to characterize the sintered bulk and confirmed its quasicrystalline structure.The electrical resistivity of the HPS quasicrystal specimen is measured from 2 K to 300 K,revealing a significantly elevated value in comparison to samples prepared via alternative methods.Nanoindentation testing demonstrates exceptional hardness and elastic modulus of our Al_(65)Cu_(20)Fe_(15)quasicrystal,consistent with existing results.The ratio of hardness to elastic modulus further highlight the potential superior wear resistance of the Al_(65)Cu_(20)Fe_(15)quasicrystal.Differential scanning calorimetry measurement conducted on the HPS Al_(65)Cu_(20)Fe_(15)quasicrystals reveal a high melting point of 877℃.
基金Project supported by the National Key R&D Program of China (Grant No. 2021YFA1400300)the National Natural Science Foundation of China (Grant Nos. 12425403, 12261131499, 12304268, 12304159, 11934017, and 11921004)+1 种基金the China Postdoctoral Science Foundation (Grant No. 2023M743741)The synchrotron x-ray diffraction experiments were performed at SPring-8 with the approval of the Japan Synchrotron Radiation Research Institute (Grant Nos. 2023B1575, 2023B1976, 2024A1506, and 2024A1695)。
文摘Perovskite oxynitrides AB(N,O)_(3), a crucial class in materials science, have attracted much attention. By precisely controlling A-and B-site ions and tuning the N/O ratio, new materials with exotic charge states and intriguing electronic behaviors can be designed and synthesized. In this work, a novel oxynitride perovskite, CeNbO_(2)N, was prepared under high-temperature and high-pressure conditions. The compound crystallizes in an orthorhombic perovskite structure in Pnma symmetry with disordered N/O distribution. The x-ray absorption spectroscopy confirms the presence of a Nb^(4+) state with 4d^(1) electronic configuration in CeNbO_(2)N. As a result, the resistivity of CeNbO_(2)N is sharply reduced compared to its counterpart CeTa^(5+)ON_(2) and other Nb^(5+) compounds. No long-range spin order is found to occur with the temperature down to 2 K in CeNbO_(2)N, while a remarkable negative magnetoresistance effect shows up at lower temperatures, probably due to the magnetic scattering arising from short-range spin correlations.
基金financially supported by the National Natural Science Foundation of China (Grant Nos. 12374013 and U2030107)the Fundamental Research Funds for the Central University (Grant No. 2020SCUNL107)+1 种基金The high-pressure in-situ imaging experiments were conducted at BL12SW of SSRF (Proposal No. 2024-SSRF-PT-505499)The NPD experiments were supported by Chinese Academy of Engineering Physics。
文摘Iron nitride(Fe_(x)N_y) is a promising candidate for the next generation of ferromagnetic materials. However, synthesizing high-quality bulk iron nitride with tuned structure and magnetic properties remains a challenge. Currently, experimental and theoretical results regarding the magnetic property of iron nitrides remain controversial. With the recent advancements in high-pressure technology, new synthetic pathways to iron nitrides have been proposed. High-pressure synthesis technology provides multidimensional possibilities for tuning the structure and magnetic properties of iron nitrides. This review summarizes recent progress in high-pressure synthesis of iron nitrides, especially the high-pressure solid-state metathesis reaction synthesis(HSM). We have summarized the reaction characteristics of HSM. The HSM reaction exhibits vector synthesis characteristics and promotes nitrogen disorder diffusion at high temperature. Due to this, the HSM reaction can achieve the synthesis of multinary iron-based metal nitrides and regulate the local magnetic moments. It serves as a powerful means for tuning the structure and magnetic properties of iron nitrides. Taking advantage of neutron diffraction in characterizing local magnetic moment and nitrogen disorder in iron nitrides, the relationship between iron local magnetic moment and nitrogen content has been elucidated. Moreover, the development of high-pressure in-situ imaging technology based on large-volume press allows the real-time observation of HSM reaction process. In this review, we also report our latest experiments on neutron diffraction and high-pressure in-situ image for the study of iron nitrides.
基金supported by Key Laboratory of Infrared Imaging Materials and Detectors,Shanghai Institute of Technical Physics,Chinese Academy of Sciences(No.IIMDKFJJ-21-10)China Postdoctoral Science Foundation(No.2018T110993).
文摘In order to achieve combined mechanical and electrical properties,multi-walled carbon nanotubes(MWCNTs)reinforced Cu/Ti_(3)SiC_(2)/C nanocomposites were further processed by high-pressure torsion(HPT).The maximum microhardness values of central and edge from the composites with 1 wt.%MWCNTs reached HV 130.0 and HV 363.5,which were 43.9%and 39.5%higher than those of the original samples,respectively.With the same content of MWCNTs,its electrical conductivity achieved 3.42×10^(7) S/m,which was increased by 78.1%compared with that of original samples.The synergistic improvement of mechanical and electrical properties is attributed to the obtained microstructure with increased homogenization and refinement,as well as improved interfacial bonding and reduced porosity.The strengthening mechanisms include dispersion and refinement strengthening for mechanical properties,as well as reduced electron scattering for electrical properties.
基金the National Natural Science Foundation of China(No.52006140)。
文摘The increasingly stringent emission regulations and fuel consumption requirements have elevated the demands of internal combustion engines with higher fuel efficiency and lower emissions.It has been widely demonstrated that fash boiling spray can generate shorter and wider spray with improved atomization and evaporation to promote a better air-fuel mixing process.In this study,macroscopic(far-field)spray morphologies and primary breakup(near-field)characteristics of a two-hole gasoline direct injection injector are investigated under non-flash boiling and flash boiling conditions.High speed macroscopic and microscopic imaging was used to capture the overall spray structure and near-field characteristics,respectively.N-Hexane is used as the test fuel with the injection pressure ranging from 10 MPa up to 40 MPa.For sub-cooled liquid fuel sprays,increasing fuel pressure contributes to enhanced fuel atomization and evaporation.Evident collapses occurred under fare flash boiling conditions,and higher injection pressure weakened this phenomenon since the spray cone angle decreased due to a higher injection velocity.
基金Project supported by Yunnan Province Basic Research Program(202101AT070141)。
文摘This study investigated the leaching of scandium from a Sc-bearing silicate ore.The Sc concentrate obtained by beneficiation pre-enrichment has 1.03×10^(−4) wt%Sc and 14.66 wt%Fe.The main Sc-bearing minerals are limonite,chlorite,sericite,and hornblende,in the form of isomorphism.High-pressure leaching(HPL)with sulfuric acid(98 wt%)and NaF was used to dispose this samples.The Sc leaching efficiency of 91.82%was obtained under the optimum conditions,which are pressure of 5.0×10^(5) Pa,A/O value of 1.1,L/S value of 1.8,NaF dosage of 2 wt%,at 130℃ for 6 h.The X-ray diffraction(XRD)and scanning electron microscopy(SEM)results show that the residue is mainly quartz phase in the multihole shape.Compared with ordinary leaching for silicate,high-pressure leaching has significant advantages in saving acid and energy consumption.
基金Project supported by the Guangxi Natural Science Foundation(AD20297001,AD20297014)the National Natural Science Foundation of China(51562032)。
文摘The magnetic properties and magnetic phase transition critical behavior of Gd_(3)Ga_5O_(12)single crystals subjected to high-pressure heat treatment were investigated.The results show that high-pressure heat treatment reduces the Curie temperature and magnetization of the sample.Under a magnetic field change of 5 T,the maximum isothermal magnetic entropy of the sample is approximately 19.73 J/(kg·K).High-pressure heat treatment increases the phase transition temperature range and leads to an increase in the magnetic refrigeration power.Both Gd_(3)Ga_(5)O_(12)single crystals and the high-pressure heat-treated sample undergo a second-order phase transition.The critical behavior of the samples aligns with the mean field model acquired via critical model fitting.This indicates that the samples exhibit long-range exchange interactions in the system near the Curie temperature.Thus,this material can be used as a magnetic refrigerant for low-temperature applications.
基金Funded by the National Natural Science Foundation of China(No.51905215)Postgraduate Research&Practice Innovation Program of Jiangsu Province(No.SJCX23_1233)+1 种基金Major Scientific and Technological Innovation Project of Shandong Province of China(No.2019JZZY020111)the National College Students Innovation and Entrepreneurship Training Program of China(No.CX2022415)。
文摘To improve the comprehensive mechanical properties of Al-Si-Cu alloy,it was treated by a high-pressure torsion process,and the effect of the deformation degree on the microstructure and properties of the Al-Si-Cu alloy was studied.The results show that the reinforcements(β-Si andθ-CuAl_(2)phases)of the Al-Si-Cu alloy are dispersed in theα-Al matrix phase with finer phase size after the treatment.The processed samples exhibit grain sizes in the submicron or even nanometer range,which effectively improves the mechanical properties of the material.The hardness and strength of the deformed alloy are both significantly raised to 268 HV and 390.04 MPa by 10 turns HPT process,and the fracture morphology shows that the material gradually transits from brittle to plastic before and after deformation.The elements interdiffusion at the interface between the phases has also been effectively enhanced.In addition,it is found that the severe plastic deformation at room temperature induces a ternary eutectic reaction,resulting in the formation of ternary Al+Si+CuAl_(2)eutectic.
基金Supported by the Sinopec"Ten Dragon"Major ProjectKey Research Projects of Sinopec(P22180)。
文摘There are various issues for CO_(2)flooding and storage in Shengli Oilfield,which are characterized by low light hydrocarbon content of oil and high miscible pressure,strong reservoir heterogeneity and low sweep efficiency,gas channeling and difficult whole-process control.Through laboratory experiments,technical research and field practice,the theory and technology of CO_(2)high pressure miscible flooding and storage are established.By increasing the formation pressure to 1.2 times the minimum miscible pressure,the miscibility of the medium-heavy components can be improved,the production percentage of oil in small pores can be increased,the displacing front developed evenly,and the swept volume expanded.Rapid high-pressure miscibility is realized through advanced pressure flooding and energy replenishment,and technologies of cascade water-alternating-gas(WAG),injection and production coupling and multistage chemical plugging are used for dynamic control of flow resistance,so as to obtain the optimum of oil recovery and CO_(2)storage factor.The research results have been applied to the Gao89-Fan142 in carbon capture,utilization and storage(CCUS)demonstration site,where the daily oil production of the block has increased from 254.6 t to 358.2 t,and the recovery degree is expected to increase by 11.6 percentage points in 15 years,providing theoretical and technical support for the large-scale development of CCUS.
文摘Repairs of corroded high-pressure pipelines are essential for fluids transportation under high pressure.One of the methods used in their repairs is the use of layered composites.The composite used must have the necessary strength.Therefore,the experiments and analytical solutions presented in this paper are performed according to the relevant standards and codes,including ASME PCC-2,ASME B31.8S,ASME B31.4,ISO 24817 and ASME B31.G.In addition,the experimental tests are replicated numerically using the finite element method.Setting the strain gauges at different distances from the defect location,can reduce the nonlinear effects,deformation,and fluctuations due to the high pressure.The direct relationship between the depth of an axial defect and the stress concentration is observed at the inner side edges of the defect.Composite reparation reduces the non-linearities related to the sharp variation of the geometry and a more reliable numerical simulation could be performed.
基金support from the National Natural Science Foundation of China(Grant Nos.51975175 and 52375329)the Projects of Natural Science Key Research of Anhui Province(2023AH051664).
文摘The Mg–Zn–Gd alloy with quasicrystal icosahedral phase was processed by high-pressure torsion (HPT). The effect of bimodal I-phase on the dynamic recrystallization was analyzed by transmission electron microscopy. The results showed that the block I-phase can stimulate obvious particle-stimulated nucleation and dynamic recrystallization (DRX) grains were preferentially formed after HPT for 5 turns, while the granular I-phase only promoted the generation of sub-grains. The orientation relationship was determined as twofold//[1210] and fivefold//(0002)_(Mg). Moreover, after HPT for 9 turns, the DRX grains induced by block I-phase appeared to grow up and coarsened. Compared with block I-phase, the grains induced by granular I-phase presented much smaller size and distributed more homogeneous due to the strong pinning effect.
