The intracontinental subduction of a>200-km-long section of the Tajik-Tarim lithosphere beneath the Pamir Mountains is proposed to explain nearly 30 km of shortening in the Tajik fold-thrust belt and the Pamir upli...The intracontinental subduction of a>200-km-long section of the Tajik-Tarim lithosphere beneath the Pamir Mountains is proposed to explain nearly 30 km of shortening in the Tajik fold-thrust belt and the Pamir uplift.Seismic imaging revealed that the upper slab was scraped and that the lower slab had subducted to a depth of>150 km.These features constitute the tectonic complexity of the Pamirs,as well as the thermal subduction mechanism involved,which remains poorly understood.Hence,in this study,high-resolution three-dimensional(3D)kinematic modeling is applied to investigate the thermal structure and geometry of the subducting slab beneath the Pamirs.The modeled slab configuration reveals distinct along-strike variations,with a steeply dipping slab beneath the southern Pamirs,a more gently inclined slab beneath the northern Pamirs,and apparent upper slab termination at shallow depths beneath the Pamirs.The thermal field reveals a cold slab core after delamination,with temperatures ranging from 400℃to 800℃,enveloped by a hotter mantle reaching~1400℃.The occurrence of intermediate-depth earthquakes aligns primarily with colder slab regions,particularly near the slab tear-off below the southwestern Pamirs,indicating a strong correlation between slab temperature and seismicity.In contrast,the northern Pamirs exhibit reduced seismicity at depth,which is likely associated with thermal weakening and delamination.The central Pamirs show a significant thermal anomaly caused by a concave slab,where the coldest crust does not descend deeply,further suggesting crustal detachment or mechanical failure.The lateral asymmetry in slab temperature possibly explains the mechanism of lateral tearing and differential slab-mantle coupling.展开更多
On January 19,2026,China's first structural interest rate cut of the year took effect.The People's Bank of China announced a 0.25 percentage point reduction in relending and rediscount rates,targeting key sect...On January 19,2026,China's first structural interest rate cut of the year took effect.The People's Bank of China announced a 0.25 percentage point reduction in relending and rediscount rates,targeting key sectors like small and micro enterprises(SMEs),technological innovation,and green transition.For the textile industry,where small and medium-sized enterprises account for over 90%of traditional manufacturing,the policy benefits will inject strong momentum into the high-quality development from multiple dimensions,including reduced financing costs,support for transformation funds,and expansion of foreign trade markets.展开更多
The flow field of molten steel and the interfacial behaviour between molten steel and liquid slag layer in medium-thin slab continuous casting mold with argon gas injection were studied by numerical simulation, in whi...The flow field of molten steel and the interfacial behaviour between molten steel and liquid slag layer in medium-thin slab continuous casting mold with argon gas injection were studied by numerical simulation, in which the effects of nozzle submergence depth and port angle, casting speed, and argon gas flow rate on the flow and the level fluctuation of molten steel were considered. The results show that the molten steel is jetted from the submerged en- try nozzle （SEN） with three ports into the mold and forms three recirculation zones including one upper recireulation zone and two lower recirculation zones. Argon gas injection results in a secondary vortex flow in the upper zone near the nozzle. For a given casting speed and argon gas flow rate, increasing the side port angle and submergence depth of nozzle can effectively restrain the steel/slag interracial fluctuation. Increasing the casting speed would prick up the level fluctuation. For a fixed casting speed, argon gas flow rate has a critical value, the interracial fluctuation with argon gas injection are stronger than the case without argon gas injection when the argon gas flow rate is less than the critical value, but when the argon gas flow rate exceeds the critical value, the level fluctuation is calmer than that without argon gas injection.展开更多
According to the analysis of the macro and micro characteristics of the center of continuous casting blooms by acid wash,SEM,metallographic and scanning-type electron microscope,there was a serious segregation and som...According to the analysis of the macro and micro characteristics of the center of continuous casting blooms by acid wash,SEM,metallographic and scanning-type electron microscope,there was a serious segregation and some shrinkage cavities in the slab;Cracks occurred at the end of the columnar crystal and spread along the boundary of the primary dendrite.At the crack enriched a large number of impurity elements,carbon,phosphorus,sulfur,whose crystal boundary segregation is the internal factor of the intermediate cracks.Determining the originated location of intermediate cracks and calculating the total strain in this area during solidification process of slab,it is found that the load is the ex-ternal factor of cracks’generation and expansion.展开更多
A three-dimensional finite-element model has been established to investigate the thermal behavior of the medium-thick slab copper casting mold with different cooling water slot designs. The mold wall temperatures meas...A three-dimensional finite-element model has been established to investigate the thermal behavior of the medium-thick slab copper casting mold with different cooling water slot designs. The mold wall temperatures measured using thermocouples buried in different positions of the mold with the original designed cooling system were analyzed to determine the corresponding heat flux profile. This profile was then used for simulation to predict the temperature distribution and the thermal stress distribution of the molds. The predicted temperatures during operation matched the plant measurements. The results showed that the maximum temperature, about 635 K in the wide hot surface, was found about 60 mm below the meniscus and 226 mm from the center of the mold. For the mold with the type I modified design, there was an insignificant decrease in temperature of about 5 K, and for the mold with the type II modified design, the maximum temperature was decreased by about 15 K and the temperature of the hot surface was distributed more uniformly along the length of the mold. The corresponding maximum thermal stress at the hot surface of the mold was reduced from 408 MPa to 386 MPa with the type II modified design. The results indicated that the modified design II is beneficial to the increase of mold life and the quality of casting slabs.展开更多
In recent years,medium entropy alloys have become a research hotspot due to their excellent physical and chemical performances.By controlling reasonable elemental composition and processing parameters,the medium entro...In recent years,medium entropy alloys have become a research hotspot due to their excellent physical and chemical performances.By controlling reasonable elemental composition and processing parameters,the medium entropy alloys can exhibit similar properties to high entropy alloys and have lower costs.In this paper,a FeCoNi medium entropy alloy precursor was prepared via sol-gel and coprecipitation methods,respectively,and FeCoNi medium entropy alloys were prepared by carbothermal and hydrogen reduction.The phases and magnetic properties of FeCoNi medium entropy alloy were investigated.Results showed that FeCoNi medium entropy alloy was produced by carbothermal and hydrogen reduction at 1500℃.Some carbon was detected in the FeCoNi medium entropy alloy prepared by carbothermal reduction.The alloy prepared by hydrogen reduction was uniform and showed a relatively high purity.Moreover,the hydrogen reduction product exhibited better saturation magnetization and lower coercivity.展开更多
The application of liquid core reduction(LCR)technology in thin slab continuous casting can refine the internal microstruc-tures of slabs and improve their production efficiency.To avoid crack risks caused by large de...The application of liquid core reduction(LCR)technology in thin slab continuous casting can refine the internal microstruc-tures of slabs and improve their production efficiency.To avoid crack risks caused by large deformation during the LCR process and to minimize the thickness of the slab in bending segments,the maximum theoretical reduction amount and the corresponding reduction scheme for the LCR process must be determined.With SPA-H weathering steel as a specific research steel grade,the distributions of tem-perature and deformation fields of a slab with the LCR process were analyzed using a three-dimensional thermal-mechanical finite ele-ment model.High-temperature tensile tests were designed to determine the critical strain of corner crack propagation and intermediate crack initiation with various strain rates and temperatures,and a prediction model of the critical strain for two typical cracks,combining the effects of strain rate and temperature,was proposed by incorporating the Zener-Hollomon parameter.The crack risks with different LCR schemes were calculated using the crack risk prediction model,and the maximum theoretical reduction amount for the SPA-H slab with a transverse section of 145 mm×1600 mm was 41.8 mm,with corresponding reduction amounts for Segment 0 to Segment 4 of 15.8,7.3,6.5,6.4,and 5.8 mm,respectively.展开更多
Purpose–The precast concrete slab track(PST)has advantages of fewer maintenance frequencies,better smooth rides and structural stability,which has been widely applied in urban rail transit.Precise positioning of prec...Purpose–The precast concrete slab track(PST)has advantages of fewer maintenance frequencies,better smooth rides and structural stability,which has been widely applied in urban rail transit.Precise positioning of precast concrete slab(PCS)is vital for keeping the initial track regularity.However,the cast-in-place process of the self-compacting concrete(SCC)filling layer generally causes a large deformation of PCS due to the water-hammer effect of flowing SCC,even cracking of PCS.Currently,the buoyancy characteristic and influencing factors of PCS during the SCC casting process have not been thoroughly studied in urban rail transit.Design/methodology/approach–In this work,a Computational Fluid Dynamics(CFD)model is established to calculate the buoyancy of PCS caused by the flowing SCC.The main influencing factors,including the inlet speed and flowability of SCC,have been analyzed and discussed.A new structural optimization scheme has been proposed for PST to reduce the buoyancy caused by the flowing SCC.Findings–The simulation and field test results showed that the buoyancy and deformation of PCS decreased obviously after adopting the new scheme.Originality/value–The findings of this study can provide guidance for the control of the deformation of PCS during the SCC construction process.展开更多
With the change of the main influencing factors such as structural configuration and impact conditions,reinforced concrete slabs exhibit different mechanical behaviors with different failure patterns,and the failure m...With the change of the main influencing factors such as structural configuration and impact conditions,reinforced concrete slabs exhibit different mechanical behaviors with different failure patterns,and the failure modes are transformed.In order to reveal the failure mode and transformation rule of reinforced concrete slabs under impact loads,a dynamic impact response test was carried out using a drop hammer test device.The dynamic data pertaining to the impact force,support reaction force,structural displacement,and reinforcement strain were obtained through the use of digital image correlation technology(DIC),impact force measurement,and strain measurement.The analysis of the ultimate damage state of the reinforced concrete slab identified four distinct types of impact failure modes:local failure by stamping,overall failure by stamping,local-overall coupling failure,and local failure by punching.Additionally,the influence laws of hammerhead shape,hammer height,and reinforcement ratio on the dynamic response and failure mode transformation of the slab were revealed.The results indicate that:(1)The local damage to the slab by the plane hammer is readily apparent,while the overall damage by the spherical hammer is more pronounced.(2)In comparison to the high reinforcement ratio slabs,the overall bending resistance of the low reinforcement ratio slabs is significantly inferior,and the slab back exhibits further cracks.(3)As the hammer height increases,the slab failure mode undergoes a transformation,shifting from local failure by stamping and overall failure by stamping to local-overall coupling failure and local failure by punching.(4)Three failure mode thresholds have been established,and by comparing the peak impact force with the failure thresholds,the failure mode of the slab can be effectively determined.展开更多
Developing high-performance alloys with gigapascal strength and excellent ductility is crucial for modern engineering applications.The concept of multi-component high/medium entropy alloys(H/MEAs)provides an innovativ...Developing high-performance alloys with gigapascal strength and excellent ductility is crucial for modern engineering applications.The concept of multi-component high/medium entropy alloys(H/MEAs)provides an innovative approach to designing such alloys.In this work,we developed the Co_(1.5)CrNi_(1.5)Al_(0.2)Ti_(0.2)MEA,which exhibits outstanding mechanical properties at room temperature through low-temperature pre-aging followed by annealing treatment.Tensile testing reveals that the MEA possesses an ultrahigh yield strength of 20±0785 MPa,an ultimate tensile strength of 2365±70 MPa,and exceptional ductility of 15.8%±1.7%.The superior tensile properties are attributed to the formation of fully recrystal-lized heterogeneous structures(HGS)composed of ultrafine grain(UFG)and fine grain(FG)regions,along with discontinuous precipitation of coherent nano-size lamellar L1_(2)precipitates.The mechanical incompatibility between the UFG region and the FG regions during deformation induces the accumulation of a large number of geometrically necessary dislocations at the interface,resulting in strain distribution and hetero-deformation-induced(HDI)stress accumulation,contributing significantly to HDI strengthening.HDI strengthening,precipitation strengthening,and grain boundary strengthening are the primary mechanisms responsible for the ultra-high yield strength of the MEA.During deformation,the dominant deformation mechanisms include dislocation slip,deformation-induced stacking faults,and Lomer-Cottrell locks,with minor deformation twinning.The synergistic interaction of these multiple deformation modes provides the MEA with excellent work hardening capability,delaying plastic instability and achieving an excellent combination of strength and ductility.This study provides an effective strategy for synergistically strengthening MEAs by combining HDI strengthening with traditional strengthening mechanisms.These findings pave the way for the development of advanced structural materials with high performance tailored for demanding applications in engineering.展开更多
The influence of Nb-V microalloying on the hot deformation behavior and microstructures of medium Mn steel(MMS)was investigated by uniaxial hot compression tests.By establishing the constitutive equations for simulati...The influence of Nb-V microalloying on the hot deformation behavior and microstructures of medium Mn steel(MMS)was investigated by uniaxial hot compression tests.By establishing the constitutive equations for simulating the measured flow curves,we successfully constructed deformation activation energy(Q)maps and processing maps for identifying the region of flow instability.We concluded the following consequences of Nb-V alloying for MMS.(i)The critical strain increases and the increment diminishes with the increasing deformation temperature,suggesting that NbC precipitates more efficiently retard dynamic recrystallization(DRX)in MMS compared with solute Nb.(ii)The deformation activation energy of MMS is significantly increased and even higher than that of some reported high Mn steels,suggesting that its ability to retard DRX is greater than that of the high Mn content.(iii)The hot workability of MMS is improved by narrowing the hot processing window for the unstable flow stress,in which fine recrystallized and coarse unrecrystallized grains are present.展开更多
The growing demand for material properties in challenging environments has led to a surge of interest in rapid composition design. Given the great potential composition space, the field of high/medium entropy alloys (...The growing demand for material properties in challenging environments has led to a surge of interest in rapid composition design. Given the great potential composition space, the field of high/medium entropy alloys (H/MEAs) still lacks effective atomic-scale composition design and screening schemes, which hinders the accurate prediction of desired composition and properties. This study proposes a novel approach for rapidly designing the composition of materials with the aim of overcoming the trade-off between strength and ductility in metal matrix composites. The effect of chemical composition on stacking fault energy (SFE), shear modulus, and phase stability was investigated through the use of molecular dynamics (MD) and thermodynamic calculation software. The alloy's low SFE, highest shear modulus, and stable face-centered cubic (FCC) phase have been identified as three standard physical quantities for rapid screening to characterize the deformation mechanism, ultimate tensile strength, phase stability, and ductility of the alloy. The calculation results indicate that the optimal composition space is expected to fall within the ranges of 17 %–34 % Ni, 33 %–50 % Co, and 25 %–33 % Mn. The comparison of stress-strain curves for various predicted components using simulated and experimental results serves to reinforce the efficacy of the method. This indicates that the screening criteria offer a necessary design concept, deviating from traditional strategies and providing crucial guidance for the rapid development and application of MEAs.展开更多
This study aimed to investigate the moment redistribution in continuous glass fiber reinforced polymer(GFRP)-concrete composite slabs caused by concrete cracking and steel bar yielding in the negative bending moment z...This study aimed to investigate the moment redistribution in continuous glass fiber reinforced polymer(GFRP)-concrete composite slabs caused by concrete cracking and steel bar yielding in the negative bending moment zone.An experimental bending moment redistribution test was conducted on continuous GFRP-concrete composite slabs,and a calculation method based on the conjugate beam method was proposed.The composite slabs were formed by combining GFRP profiles with a concrete layer and supported on steel beams to create two-span continuous composite slab specimens.Two methods,epoxy resin bonding,and stud connection,were used to connect the composite slabs with the steel beams.The experimental findings showed that the specimen connected with epoxy resin exhibited two moments redistribution phenomena during the loading process:concrete cracking and steel bar yielding at the internal support.In contrast,the composite slab connected with steel beams by studs exhibited only one-moment redistribution phenomenon throughout the loading process.As the concrete at the internal support cracked,the bending moment decreased in the internal support section and increased in the midspan section.When the steel bars yielded,the bending moment further decreased in the internal support section and increased in the mid-span section.Since GFRP profiles do not experience cracking,there was no significant decrease in the bending moment of the mid-span section.All test specimens experienced compressive failure of concrete at the mid-span section.Calculation results showed good agreement between the calculated and experimental values of bending moments in the mid-span section and internal support section.The proposed model can effectively predict the moment redistribution behavior of continuous GFRP-concrete composite slabs.展开更多
Low-concentration coal mine methane(LC-CMM),which is predominantly composed of methane,serves as a clean and low-carbon energy resource with significant potential for utilization.Utilizing LC-CMM as fuel for solid oxi...Low-concentration coal mine methane(LC-CMM),which is predominantly composed of methane,serves as a clean and low-carbon energy resource with significant potential for utilization.Utilizing LC-CMM as fuel for solid oxide fuel cells(SOFCs)represents an efficient and promising strategy for its effective utilization.However,direct application in Ni-based anodes induces carbon deposition,which severely degrades cell performance.Herein,a medium-entropy oxide Sr_(2)FeNi_(0.1)Cr_(0.3)Mn_(0.3)Mo_(0.3)O_(6−δ)(SFNCMM)was developed as an anode internal reforming catalyst.Following reduction treatment,FeNi_(3) nano-alloy particles precipitate on the surface of the material,thereby significantly enhancing its catalytic activity for LC-CMM reforming process.The catalyst achieved a methane conversion rate of 53.3%,demonstrating excellent catalytic performance.Electrochemical evaluations revealed that SFNCMM-Gd_(0.1)Ce_(0.9)O_(2−δ)(GDC)with a weight ratio of 7:3 exhibited superior electrochemical performance when employed as the anodic catalytic layer.With H_(2) and LC-CMM as fuels,the single cell achieved maximum power densities of 1467.32 and 1116.97 mW·cm^(−2) at 800℃,respectively,with corresponding polarization impedances of 0.17 and 1.35Ω·cm^(2).Furthermore,the single cell maintained stable operation for over 100 h under LC-CMM fueling without significant carbon deposition,confirming its robust resistance to carbon formation.These results underscore the potential of medium-entropy oxides as highly effective catalytic layers for mitigating carbon deposition in SOFCs.展开更多
Subduction zones are major convergent boundaries,where the downgoing oceanic plates usually form continuous tabular slabs extending deep into the Earth’s interior.However,many subducting slabs especially those with y...Subduction zones are major convergent boundaries,where the downgoing oceanic plates usually form continuous tabular slabs extending deep into the Earth’s interior.However,many subducting slabs especially those with young ages,exhibit complex geometry,with varying degrees of influence on the overlying continent and surface environment.To better understand the mechanism of such slab deformation,we apply four-dimensional finite element geodynamic models with data assimilation to investigate the evolution of the Cocos subduction in Central America,where a double-slab configuration with complex tearing has recently been observed.We reproduce the subduction history of the Cocos slab since the Eocene.During this period,multiple episodes of tearing occurred within the Cocos slab,starting at 25 Ma.We find that the ancient Farallon slab,subducted during the Mesozoic,enhances the lateral pressure gradient across the slab hinge,promoting eastward mantle flow and tearing of the Cocos slab.The repeated tearing and subduction of the young Cocos plate have shaped the complex slab configuration in the region.展开更多
BACKGROUND Oil-based iodinated contrast media have excellent contrast properties and are widely used for hysterosalpingographic evaluation of female infertility.On abdominal radiography and computed tomography(CT)scan...BACKGROUND Oil-based iodinated contrast media have excellent contrast properties and are widely used for hysterosalpingographic evaluation of female infertility.On abdominal radiography and computed tomography(CT)scans,their radiodensity is similar to that of metallic objects,which can sometimes lead to diagnostic confusion in the postoperative settings.In this case,retained oil-based contrast medium was observed on an abdominal radiograph following a cesarean section,making it difficult to differentiate from an intraperitoneal foreign body from surgery.The patient was a 37-year-old pregnant woman who was referred to our hospital at 32 weeks and 1 day of pregnancy due to complete placenta previa for mana-gement of pregnancy and delivery.An elective cesarean section was performed at 37 weeks and 3 days.A plain abdominal radiograph taken immediately after surgery revealed a near-round,hyperdense,mass-like shadow with a regular margin in the pelvic cavity.An intraperitoneal foreign body was suspected;therefore,an abdominal CT scan was performed.The foreign body was located on the left side of the pouch of Douglas and had a CT value of 7000 Hounsfield units,similar to that of metals.The CT value strongly suggested the presence of an artificial object.However,further inquiries with the patient and her previous physician revealed a history of hysterosalpingography.Accordingly,retained oil-based iodinated contrast medium was suspected,and observation of the object’s course was adopted.CONCLUSION When intraperitoneal foreign bodies are suspected on postoperative radiographs,the possibility of oil-based iodinated contrast medium retention should be considered.展开更多
Crystal defects and morphological modifications are popular strategies to enhance the catalytic activity of heterogeneous semiconductor photocatalysts.Despite defect engineering and morphology control show their succe...Crystal defects and morphological modifications are popular strategies to enhance the catalytic activity of heterogeneous semiconductor photocatalysts.Despite defect engineering and morphology control show their successful applications in ZnO,the effects of curved surface modifications on the photocatalytic performance of ZnO and their interplay with the defect formation remain unclear.To resolve this puzzle,we systemically investigate the joint effects of curvature and defect formation on the electronic structure,optoelectronic properties,and photocatalytic performance of ZnO slabs using first-principles calculations.We find that curvature deformation effectively narrows the electronic bandgap by up to 1.6 eV and shifts the p-/d-band centers,thereby enhancing light absorption in the visible and near-ultraviolet regions.Besides,curvature deformation stimulates self-polarization,facilitating the separation of photogenerated electrons and holes.Also,curvature deformation promotes the formation of defects by reducing defect formation energy(by up to 1.0 eV),thus creating abundant reaction sites for photocatalysis.Intriguingly,the synergistic interaction between curvature and defect deformation further strengthens the self-polarization,narrows the electronic bandgaps,adjusts the p-/d-band centers to improve the optoelectronic properties,and influences the dissociation and free energy barriers of intermediates.Consequently,our findings reveal that this synergy substantially enhances the photocatalytic performance of ZnO slabs,providing deeper insights into the role of defect engineering and morphology control on photocatalysis.展开更多
[Objectives]To evaluate the performance of two rapid chromogenic media for the detection of Bacillus cereus in milk powder,and verify the media's inclusivity,exclusivity,and accuracy,and to assess their applicabil...[Objectives]To evaluate the performance of two rapid chromogenic media for the detection of Bacillus cereus in milk powder,and verify the media's inclusivity,exclusivity,and accuracy,and to assess their applicability for the quantitative detection of B.cereus.[Methods]B.cereus in milk powder samples was quantified using two rapid chromogenic media in combination with the national standard method.Agreement between the quantitative results from the three methods was subsequently assessed for agreement via a paired t-test.[Results]No significant differences were observed between the bacterial counts yielded by the two rapid chromogenic media and the national standard method(P>0.05),with excellent agreement between them.[Conclusions]The method of rapid chromogenic culture medium is rapid and simple.展开更多
Amid increasingly frequent military conflicts and explosion events,accurately predicting the dynamic response of reinforced concrete(RC) slabs,key load-bearing components in building structures,is essential for unders...Amid increasingly frequent military conflicts and explosion events,accurately predicting the dynamic response of reinforced concrete(RC) slabs,key load-bearing components in building structures,is essential for understanding blast-induced damage and enhancing structural protection.However,current approaches predominantly rely on experimental tests,finite element(FE) simulations,and conventional machine learning(ML) techniques,which are o ften costly,inefficie nt,narrowly applicable,and insufficiently accurate.To overcome these challenges,this study aims to optimize ML models,refine architectural designs,and improve model interpretability.A comprehensive dataset comprising 489 samples was constructed by integrating experimental and simulation data from existing literature,incorporating 15 input features and one target variable.Based on this dataset,a novel method,termed MOPSO-TXGBoost,was proposed.Building on XGBoost as a baseline,the method employs multiobjective particle swarm optimization(MOPSO) for hyperparameter tuning,introduces a tri-stream stacking architecture to enhance feature representation,and trains three distinct models to improve generalization performance.A weighted fusion strategy is employed to further enhance the accuracy of predictio n.Additio nally,a model comprehensive evaluation(MCE) index is introduced,which integrates error metrics and fitting performance to facilitate systematic model assessment.Experimental results indicate that,compared with the baseline XGBoost model,the proposed approach reduces prediction error by 61.4% and increases the coefficient of determination(R^(2)) by 0.217.Moreover,it outperforms several mainstream machine learning(ML) algorithms.The findings of this study advance ML-based blast damage prediction and provide theoretical support for safety assessment and protection optimization of RC slab structures.展开更多
基金the Chinese Academy of Sciences Pioneer Hundred Talents Program and the Second Tibetan Plateau Scientific Expedition and Research Program(Grant No.2019QZKK0708)supported by a MEXT(Ministry of Education,Culture,Sports,Science and Technology)KAKENHI(Grants-in-Aid for Scientific Research)grant(Grant No.21H05203)Kobe University Strategic International Collaborative Research Grant(Type B Fostering Joint Research).
文摘The intracontinental subduction of a>200-km-long section of the Tajik-Tarim lithosphere beneath the Pamir Mountains is proposed to explain nearly 30 km of shortening in the Tajik fold-thrust belt and the Pamir uplift.Seismic imaging revealed that the upper slab was scraped and that the lower slab had subducted to a depth of>150 km.These features constitute the tectonic complexity of the Pamirs,as well as the thermal subduction mechanism involved,which remains poorly understood.Hence,in this study,high-resolution three-dimensional(3D)kinematic modeling is applied to investigate the thermal structure and geometry of the subducting slab beneath the Pamirs.The modeled slab configuration reveals distinct along-strike variations,with a steeply dipping slab beneath the southern Pamirs,a more gently inclined slab beneath the northern Pamirs,and apparent upper slab termination at shallow depths beneath the Pamirs.The thermal field reveals a cold slab core after delamination,with temperatures ranging from 400℃to 800℃,enveloped by a hotter mantle reaching~1400℃.The occurrence of intermediate-depth earthquakes aligns primarily with colder slab regions,particularly near the slab tear-off below the southwestern Pamirs,indicating a strong correlation between slab temperature and seismicity.In contrast,the northern Pamirs exhibit reduced seismicity at depth,which is likely associated with thermal weakening and delamination.The central Pamirs show a significant thermal anomaly caused by a concave slab,where the coldest crust does not descend deeply,further suggesting crustal detachment or mechanical failure.The lateral asymmetry in slab temperature possibly explains the mechanism of lateral tearing and differential slab-mantle coupling.
文摘On January 19,2026,China's first structural interest rate cut of the year took effect.The People's Bank of China announced a 0.25 percentage point reduction in relending and rediscount rates,targeting key sectors like small and micro enterprises(SMEs),technological innovation,and green transition.For the textile industry,where small and medium-sized enterprises account for over 90%of traditional manufacturing,the policy benefits will inject strong momentum into the high-quality development from multiple dimensions,including reduced financing costs,support for transformation funds,and expansion of foreign trade markets.
基金Item Sponsored by National Natural Science Foundation of China and Baosteel Co(50674020)
文摘The flow field of molten steel and the interfacial behaviour between molten steel and liquid slag layer in medium-thin slab continuous casting mold with argon gas injection were studied by numerical simulation, in which the effects of nozzle submergence depth and port angle, casting speed, and argon gas flow rate on the flow and the level fluctuation of molten steel were considered. The results show that the molten steel is jetted from the submerged en- try nozzle （SEN） with three ports into the mold and forms three recirculation zones including one upper recireulation zone and two lower recirculation zones. Argon gas injection results in a secondary vortex flow in the upper zone near the nozzle. For a given casting speed and argon gas flow rate, increasing the side port angle and submergence depth of nozzle can effectively restrain the steel/slag interracial fluctuation. Increasing the casting speed would prick up the level fluctuation. For a fixed casting speed, argon gas flow rate has a critical value, the interracial fluctuation with argon gas injection are stronger than the case without argon gas injection when the argon gas flow rate is less than the critical value, but when the argon gas flow rate exceeds the critical value, the level fluctuation is calmer than that without argon gas injection.
文摘According to the analysis of the macro and micro characteristics of the center of continuous casting blooms by acid wash,SEM,metallographic and scanning-type electron microscope,there was a serious segregation and some shrinkage cavities in the slab;Cracks occurred at the end of the columnar crystal and spread along the boundary of the primary dendrite.At the crack enriched a large number of impurity elements,carbon,phosphorus,sulfur,whose crystal boundary segregation is the internal factor of the intermediate cracks.Determining the originated location of intermediate cracks and calculating the total strain in this area during solidification process of slab,it is found that the load is the ex-ternal factor of cracks’generation and expansion.
基金financially supported by the National Natural Science Foundation of China(Nos.51525401,51274054,U1332115,51401044)the Science and Technology Planning Project of Dalian(No.2013A16GX110)+1 种基金the China Postdoctoral Science Foundation(2015M581331)the Fundamental Research Funds for the Central Universities
文摘A three-dimensional finite-element model has been established to investigate the thermal behavior of the medium-thick slab copper casting mold with different cooling water slot designs. The mold wall temperatures measured using thermocouples buried in different positions of the mold with the original designed cooling system were analyzed to determine the corresponding heat flux profile. This profile was then used for simulation to predict the temperature distribution and the thermal stress distribution of the molds. The predicted temperatures during operation matched the plant measurements. The results showed that the maximum temperature, about 635 K in the wide hot surface, was found about 60 mm below the meniscus and 226 mm from the center of the mold. For the mold with the type I modified design, there was an insignificant decrease in temperature of about 5 K, and for the mold with the type II modified design, the maximum temperature was decreased by about 15 K and the temperature of the hot surface was distributed more uniformly along the length of the mold. The corresponding maximum thermal stress at the hot surface of the mold was reduced from 408 MPa to 386 MPa with the type II modified design. The results indicated that the modified design II is beneficial to the increase of mold life and the quality of casting slabs.
基金financially supported by the National Natural Science Foundation of China(Nos.52074078 and 52374327)the Applied Fundamental Research Program of Liaoning Province,China(No.2023JH2/101600002)+3 种基金the Liaoning Provincial Natural Science Foundation,China(No.2022-YQ-09)the Shenyang Young Middle-Aged Scientific and Technological Innovation Talent Support Program,China(No.RC220491)the Liaoning Province Steel Industry-University-Research Innovation Alliance Cooperation Project of Bensteel Group,China(No.KJBLM202202)the Fundamental Research Funds for the Central Universities,China(Nos.N2201023 and N2325009)。
文摘In recent years,medium entropy alloys have become a research hotspot due to their excellent physical and chemical performances.By controlling reasonable elemental composition and processing parameters,the medium entropy alloys can exhibit similar properties to high entropy alloys and have lower costs.In this paper,a FeCoNi medium entropy alloy precursor was prepared via sol-gel and coprecipitation methods,respectively,and FeCoNi medium entropy alloys were prepared by carbothermal and hydrogen reduction.The phases and magnetic properties of FeCoNi medium entropy alloy were investigated.Results showed that FeCoNi medium entropy alloy was produced by carbothermal and hydrogen reduction at 1500℃.Some carbon was detected in the FeCoNi medium entropy alloy prepared by carbothermal reduction.The alloy prepared by hydrogen reduction was uniform and showed a relatively high purity.Moreover,the hydrogen reduction product exhibited better saturation magnetization and lower coercivity.
基金supported by the National Natural Science Foundation of China(No.52474355)the Liaoning Province Science and Technology Plan Joint Program(Key Research and Development Program Project),China(Nos.2022JH25/10200003 and 2023JH2/101800058).
文摘The application of liquid core reduction(LCR)technology in thin slab continuous casting can refine the internal microstruc-tures of slabs and improve their production efficiency.To avoid crack risks caused by large deformation during the LCR process and to minimize the thickness of the slab in bending segments,the maximum theoretical reduction amount and the corresponding reduction scheme for the LCR process must be determined.With SPA-H weathering steel as a specific research steel grade,the distributions of tem-perature and deformation fields of a slab with the LCR process were analyzed using a three-dimensional thermal-mechanical finite ele-ment model.High-temperature tensile tests were designed to determine the critical strain of corner crack propagation and intermediate crack initiation with various strain rates and temperatures,and a prediction model of the critical strain for two typical cracks,combining the effects of strain rate and temperature,was proposed by incorporating the Zener-Hollomon parameter.The crack risks with different LCR schemes were calculated using the crack risk prediction model,and the maximum theoretical reduction amount for the SPA-H slab with a transverse section of 145 mm×1600 mm was 41.8 mm,with corresponding reduction amounts for Segment 0 to Segment 4 of 15.8,7.3,6.5,6.4,and 5.8 mm,respectively.
文摘Purpose–The precast concrete slab track(PST)has advantages of fewer maintenance frequencies,better smooth rides and structural stability,which has been widely applied in urban rail transit.Precise positioning of precast concrete slab(PCS)is vital for keeping the initial track regularity.However,the cast-in-place process of the self-compacting concrete(SCC)filling layer generally causes a large deformation of PCS due to the water-hammer effect of flowing SCC,even cracking of PCS.Currently,the buoyancy characteristic and influencing factors of PCS during the SCC casting process have not been thoroughly studied in urban rail transit.Design/methodology/approach–In this work,a Computational Fluid Dynamics(CFD)model is established to calculate the buoyancy of PCS caused by the flowing SCC.The main influencing factors,including the inlet speed and flowability of SCC,have been analyzed and discussed.A new structural optimization scheme has been proposed for PST to reduce the buoyancy caused by the flowing SCC.Findings–The simulation and field test results showed that the buoyancy and deformation of PCS decreased obviously after adopting the new scheme.Originality/value–The findings of this study can provide guidance for the control of the deformation of PCS during the SCC construction process.
基金Supported by the National Natural Science Foundation of China(Grant No.52078283)Shandong Provincial Natural Science Foundation(Project No.ZR2024MA094)。
文摘With the change of the main influencing factors such as structural configuration and impact conditions,reinforced concrete slabs exhibit different mechanical behaviors with different failure patterns,and the failure modes are transformed.In order to reveal the failure mode and transformation rule of reinforced concrete slabs under impact loads,a dynamic impact response test was carried out using a drop hammer test device.The dynamic data pertaining to the impact force,support reaction force,structural displacement,and reinforcement strain were obtained through the use of digital image correlation technology(DIC),impact force measurement,and strain measurement.The analysis of the ultimate damage state of the reinforced concrete slab identified four distinct types of impact failure modes:local failure by stamping,overall failure by stamping,local-overall coupling failure,and local failure by punching.Additionally,the influence laws of hammerhead shape,hammer height,and reinforcement ratio on the dynamic response and failure mode transformation of the slab were revealed.The results indicate that:(1)The local damage to the slab by the plane hammer is readily apparent,while the overall damage by the spherical hammer is more pronounced.(2)In comparison to the high reinforcement ratio slabs,the overall bending resistance of the low reinforcement ratio slabs is significantly inferior,and the slab back exhibits further cracks.(3)As the hammer height increases,the slab failure mode undergoes a transformation,shifting from local failure by stamping and overall failure by stamping to local-overall coupling failure and local failure by punching.(4)Three failure mode thresholds have been established,and by comparing the peak impact force with the failure thresholds,the failure mode of the slab can be effectively determined.
基金supported by the National Key Research and Development Program of China(No.2022YFA1603800)the National Natural Science Foundation of China(No.12274362).
文摘Developing high-performance alloys with gigapascal strength and excellent ductility is crucial for modern engineering applications.The concept of multi-component high/medium entropy alloys(H/MEAs)provides an innovative approach to designing such alloys.In this work,we developed the Co_(1.5)CrNi_(1.5)Al_(0.2)Ti_(0.2)MEA,which exhibits outstanding mechanical properties at room temperature through low-temperature pre-aging followed by annealing treatment.Tensile testing reveals that the MEA possesses an ultrahigh yield strength of 20±0785 MPa,an ultimate tensile strength of 2365±70 MPa,and exceptional ductility of 15.8%±1.7%.The superior tensile properties are attributed to the formation of fully recrystal-lized heterogeneous structures(HGS)composed of ultrafine grain(UFG)and fine grain(FG)regions,along with discontinuous precipitation of coherent nano-size lamellar L1_(2)precipitates.The mechanical incompatibility between the UFG region and the FG regions during deformation induces the accumulation of a large number of geometrically necessary dislocations at the interface,resulting in strain distribution and hetero-deformation-induced(HDI)stress accumulation,contributing significantly to HDI strengthening.HDI strengthening,precipitation strengthening,and grain boundary strengthening are the primary mechanisms responsible for the ultra-high yield strength of the MEA.During deformation,the dominant deformation mechanisms include dislocation slip,deformation-induced stacking faults,and Lomer-Cottrell locks,with minor deformation twinning.The synergistic interaction of these multiple deformation modes provides the MEA with excellent work hardening capability,delaying plastic instability and achieving an excellent combination of strength and ductility.This study provides an effective strategy for synergistically strengthening MEAs by combining HDI strengthening with traditional strengthening mechanisms.These findings pave the way for the development of advanced structural materials with high performance tailored for demanding applications in engineering.
基金financial support from the National Natural Science Foundation of China(Nos.52233018 and 51831002)the China Baowu Low Carbon Metallurgy Innovation Foudation(No.BWLCF202213)。
文摘The influence of Nb-V microalloying on the hot deformation behavior and microstructures of medium Mn steel(MMS)was investigated by uniaxial hot compression tests.By establishing the constitutive equations for simulating the measured flow curves,we successfully constructed deformation activation energy(Q)maps and processing maps for identifying the region of flow instability.We concluded the following consequences of Nb-V alloying for MMS.(i)The critical strain increases and the increment diminishes with the increasing deformation temperature,suggesting that NbC precipitates more efficiently retard dynamic recrystallization(DRX)in MMS compared with solute Nb.(ii)The deformation activation energy of MMS is significantly increased and even higher than that of some reported high Mn steels,suggesting that its ability to retard DRX is greater than that of the high Mn content.(iii)The hot workability of MMS is improved by narrowing the hot processing window for the unstable flow stress,in which fine recrystallized and coarse unrecrystallized grains are present.
基金funding from the National Natural Science Foundation of China(Nos.52063017 and 52061025)the Major Science and Technology Project of Gansu Province(Nos.22ZD6GA008 and 20ZD7GJ008)+3 种基金the Natural Science Foundation of Gansu Province(No.23JRRA820)The Science and Technology Project of Major Science and Technology Project of Gansu Province(No.22ZD6GA008)the Science and Technology Project of Gansu Province(No.23YFGA0058)the College Industry Support Plan of Gansu Province(No.2023CYZC-27).
文摘The growing demand for material properties in challenging environments has led to a surge of interest in rapid composition design. Given the great potential composition space, the field of high/medium entropy alloys (H/MEAs) still lacks effective atomic-scale composition design and screening schemes, which hinders the accurate prediction of desired composition and properties. This study proposes a novel approach for rapidly designing the composition of materials with the aim of overcoming the trade-off between strength and ductility in metal matrix composites. The effect of chemical composition on stacking fault energy (SFE), shear modulus, and phase stability was investigated through the use of molecular dynamics (MD) and thermodynamic calculation software. The alloy's low SFE, highest shear modulus, and stable face-centered cubic (FCC) phase have been identified as three standard physical quantities for rapid screening to characterize the deformation mechanism, ultimate tensile strength, phase stability, and ductility of the alloy. The calculation results indicate that the optimal composition space is expected to fall within the ranges of 17 %–34 % Ni, 33 %–50 % Co, and 25 %–33 % Mn. The comparison of stress-strain curves for various predicted components using simulated and experimental results serves to reinforce the efficacy of the method. This indicates that the screening criteria offer a necessary design concept, deviating from traditional strategies and providing crucial guidance for the rapid development and application of MEAs.
基金supported by National Natural Science Foundation of China(Project No.51878156,received by Wen-Wei Wang) and EPC Innovation Consulting Project for Longkou Nanshan LNG Phase I Receiving Terminal(Z2000LGENT0399,received by Wen-Wei Wang and ZhaoJun Zhang).
文摘This study aimed to investigate the moment redistribution in continuous glass fiber reinforced polymer(GFRP)-concrete composite slabs caused by concrete cracking and steel bar yielding in the negative bending moment zone.An experimental bending moment redistribution test was conducted on continuous GFRP-concrete composite slabs,and a calculation method based on the conjugate beam method was proposed.The composite slabs were formed by combining GFRP profiles with a concrete layer and supported on steel beams to create two-span continuous composite slab specimens.Two methods,epoxy resin bonding,and stud connection,were used to connect the composite slabs with the steel beams.The experimental findings showed that the specimen connected with epoxy resin exhibited two moments redistribution phenomena during the loading process:concrete cracking and steel bar yielding at the internal support.In contrast,the composite slab connected with steel beams by studs exhibited only one-moment redistribution phenomenon throughout the loading process.As the concrete at the internal support cracked,the bending moment decreased in the internal support section and increased in the midspan section.When the steel bars yielded,the bending moment further decreased in the internal support section and increased in the mid-span section.Since GFRP profiles do not experience cracking,there was no significant decrease in the bending moment of the mid-span section.All test specimens experienced compressive failure of concrete at the mid-span section.Calculation results showed good agreement between the calculated and experimental values of bending moments in the mid-span section and internal support section.The proposed model can effectively predict the moment redistribution behavior of continuous GFRP-concrete composite slabs.
基金supported by the National Key R&D Program of China(No.2024YFB4007501)the Natural Science Foundation of Jiangsu Province(No.BK20240109)the project of Jiangsu Key Laboratory for Clean Utilization of Carbon Resources(No.BM2024007).
文摘Low-concentration coal mine methane(LC-CMM),which is predominantly composed of methane,serves as a clean and low-carbon energy resource with significant potential for utilization.Utilizing LC-CMM as fuel for solid oxide fuel cells(SOFCs)represents an efficient and promising strategy for its effective utilization.However,direct application in Ni-based anodes induces carbon deposition,which severely degrades cell performance.Herein,a medium-entropy oxide Sr_(2)FeNi_(0.1)Cr_(0.3)Mn_(0.3)Mo_(0.3)O_(6−δ)(SFNCMM)was developed as an anode internal reforming catalyst.Following reduction treatment,FeNi_(3) nano-alloy particles precipitate on the surface of the material,thereby significantly enhancing its catalytic activity for LC-CMM reforming process.The catalyst achieved a methane conversion rate of 53.3%,demonstrating excellent catalytic performance.Electrochemical evaluations revealed that SFNCMM-Gd_(0.1)Ce_(0.9)O_(2−δ)(GDC)with a weight ratio of 7:3 exhibited superior electrochemical performance when employed as the anodic catalytic layer.With H_(2) and LC-CMM as fuels,the single cell achieved maximum power densities of 1467.32 and 1116.97 mW·cm^(−2) at 800℃,respectively,with corresponding polarization impedances of 0.17 and 1.35Ω·cm^(2).Furthermore,the single cell maintained stable operation for over 100 h under LC-CMM fueling without significant carbon deposition,confirming its robust resistance to carbon formation.These results underscore the potential of medium-entropy oxides as highly effective catalytic layers for mitigating carbon deposition in SOFCs.
基金supported by the Strategy Priority Research Program(Category B)of the Chinese Academy of Sciences(Grant No.XDB0710000)the National Natural Science Foundation of China(Grant No.92355302)supported by the National Supercomputer Center in Tianjin.
文摘Subduction zones are major convergent boundaries,where the downgoing oceanic plates usually form continuous tabular slabs extending deep into the Earth’s interior.However,many subducting slabs especially those with young ages,exhibit complex geometry,with varying degrees of influence on the overlying continent and surface environment.To better understand the mechanism of such slab deformation,we apply four-dimensional finite element geodynamic models with data assimilation to investigate the evolution of the Cocos subduction in Central America,where a double-slab configuration with complex tearing has recently been observed.We reproduce the subduction history of the Cocos slab since the Eocene.During this period,multiple episodes of tearing occurred within the Cocos slab,starting at 25 Ma.We find that the ancient Farallon slab,subducted during the Mesozoic,enhances the lateral pressure gradient across the slab hinge,promoting eastward mantle flow and tearing of the Cocos slab.The repeated tearing and subduction of the young Cocos plate have shaped the complex slab configuration in the region.
文摘BACKGROUND Oil-based iodinated contrast media have excellent contrast properties and are widely used for hysterosalpingographic evaluation of female infertility.On abdominal radiography and computed tomography(CT)scans,their radiodensity is similar to that of metallic objects,which can sometimes lead to diagnostic confusion in the postoperative settings.In this case,retained oil-based contrast medium was observed on an abdominal radiograph following a cesarean section,making it difficult to differentiate from an intraperitoneal foreign body from surgery.The patient was a 37-year-old pregnant woman who was referred to our hospital at 32 weeks and 1 day of pregnancy due to complete placenta previa for mana-gement of pregnancy and delivery.An elective cesarean section was performed at 37 weeks and 3 days.A plain abdominal radiograph taken immediately after surgery revealed a near-round,hyperdense,mass-like shadow with a regular margin in the pelvic cavity.An intraperitoneal foreign body was suspected;therefore,an abdominal CT scan was performed.The foreign body was located on the left side of the pouch of Douglas and had a CT value of 7000 Hounsfield units,similar to that of metals.The CT value strongly suggested the presence of an artificial object.However,further inquiries with the patient and her previous physician revealed a history of hysterosalpingography.Accordingly,retained oil-based iodinated contrast medium was suspected,and observation of the object’s course was adopted.CONCLUSION When intraperitoneal foreign bodies are suspected on postoperative radiographs,the possibility of oil-based iodinated contrast medium retention should be considered.
基金supported by the National Key R&D Program of China(No.2021YFA1502300)the National Natural Science Foundation of China(Nos.22103012,22173105)+2 种基金the Natural Science Foundation of Fujian Province(Nos.2024J01456,2024J01191)the Selfdeployment Project Research Program of Haixi Institutes,Chinese Academy of Sciences(No.CXZX-2022-GH10)the CAS Youth Interdisciplinary Team.
文摘Crystal defects and morphological modifications are popular strategies to enhance the catalytic activity of heterogeneous semiconductor photocatalysts.Despite defect engineering and morphology control show their successful applications in ZnO,the effects of curved surface modifications on the photocatalytic performance of ZnO and their interplay with the defect formation remain unclear.To resolve this puzzle,we systemically investigate the joint effects of curvature and defect formation on the electronic structure,optoelectronic properties,and photocatalytic performance of ZnO slabs using first-principles calculations.We find that curvature deformation effectively narrows the electronic bandgap by up to 1.6 eV and shifts the p-/d-band centers,thereby enhancing light absorption in the visible and near-ultraviolet regions.Besides,curvature deformation stimulates self-polarization,facilitating the separation of photogenerated electrons and holes.Also,curvature deformation promotes the formation of defects by reducing defect formation energy(by up to 1.0 eV),thus creating abundant reaction sites for photocatalysis.Intriguingly,the synergistic interaction between curvature and defect deformation further strengthens the self-polarization,narrows the electronic bandgaps,adjusts the p-/d-band centers to improve the optoelectronic properties,and influences the dissociation and free energy barriers of intermediates.Consequently,our findings reveal that this synergy substantially enhances the photocatalytic performance of ZnO slabs,providing deeper insights into the role of defect engineering and morphology control on photocatalysis.
基金Supported by the Inner Mongolia Autonomous Region's Key Research and Achievement Transformation Plan(2025YFSH0029).
文摘[Objectives]To evaluate the performance of two rapid chromogenic media for the detection of Bacillus cereus in milk powder,and verify the media's inclusivity,exclusivity,and accuracy,and to assess their applicability for the quantitative detection of B.cereus.[Methods]B.cereus in milk powder samples was quantified using two rapid chromogenic media in combination with the national standard method.Agreement between the quantitative results from the three methods was subsequently assessed for agreement via a paired t-test.[Results]No significant differences were observed between the bacterial counts yielded by the two rapid chromogenic media and the national standard method(P>0.05),with excellent agreement between them.[Conclusions]The method of rapid chromogenic culture medium is rapid and simple.
文摘Amid increasingly frequent military conflicts and explosion events,accurately predicting the dynamic response of reinforced concrete(RC) slabs,key load-bearing components in building structures,is essential for understanding blast-induced damage and enhancing structural protection.However,current approaches predominantly rely on experimental tests,finite element(FE) simulations,and conventional machine learning(ML) techniques,which are o ften costly,inefficie nt,narrowly applicable,and insufficiently accurate.To overcome these challenges,this study aims to optimize ML models,refine architectural designs,and improve model interpretability.A comprehensive dataset comprising 489 samples was constructed by integrating experimental and simulation data from existing literature,incorporating 15 input features and one target variable.Based on this dataset,a novel method,termed MOPSO-TXGBoost,was proposed.Building on XGBoost as a baseline,the method employs multiobjective particle swarm optimization(MOPSO) for hyperparameter tuning,introduces a tri-stream stacking architecture to enhance feature representation,and trains three distinct models to improve generalization performance.A weighted fusion strategy is employed to further enhance the accuracy of predictio n.Additio nally,a model comprehensive evaluation(MCE) index is introduced,which integrates error metrics and fitting performance to facilitate systematic model assessment.Experimental results indicate that,compared with the baseline XGBoost model,the proposed approach reduces prediction error by 61.4% and increases the coefficient of determination(R^(2)) by 0.217.Moreover,it outperforms several mainstream machine learning(ML) algorithms.The findings of this study advance ML-based blast damage prediction and provide theoretical support for safety assessment and protection optimization of RC slab structures.
