Background:Continuous care for children with enterostomy and their families has been gaining popularity in China.Objective:To evaluate the feasibility of continuous care for children with enterostomy and their familie...Background:Continuous care for children with enterostomy and their families has been gaining popularity in China.Objective:To evaluate the feasibility of continuous care for children with enterostomy and their families in China.Methods:The PubMed,Web of Science,Embase,Cochrane Library,EBSCO,CNKI,CBM,VIP,and WanFang were searched for clinical trials until December 30,2025.Two reviewers independently searched articles,evaluated quality and extracted data.This review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses(PRISMA).Results:33 studies involving 2774 participants were included.The meta-analysis showed that continuous care strategy can significantly reduce the incidence of complications in children with enterostomy(OR=0.20,95%CI=0.16-0.26,p<0.001,I2=0%),effectively improve the family caregiver ability for enterostomy(MD=-10.34,95%CI=-13.82 to-6.85,p<0.001,I2=99%),shorten the time for family members to replace stoma bags(MD=-13.57,95%CI=-19.66 to-7.49,p<0.001,I2=100%),and alleviate negative emotions such as anxiety(SMD=-1.80,95%CI=-2.36 to-1.23,p<0.001,I2=92%)and depression(SMD=-1.54,95%CI=-2.04 to-1.04,p<0.001,I2=89%)in the families of the affected children.Conclusions:Continuous care can reduce complications of enterostomy in children,improve the family caregiver ability for enterostomy and alleviate negative emotions of family members such as anxiety and depression.展开更多
Local resonant acoustic metamaterials have broad applications in sound insulation,yet their single-configuration designs often exhibit limited and discontinuous bandgap widths,hindering full-frequency noise attenuatio...Local resonant acoustic metamaterials have broad applications in sound insulation,yet their single-configuration designs often exhibit limited and discontinuous bandgap widths,hindering full-frequency noise attenuation across the human auditory range.This study presents a double-phase fidget-spinner-shaped acoustic metamaterial(DFAM),specifically designed to achieve an ultra-broad,low-frequency continuous bandgap by means of synergistic structural optimization,enabling effective and robust control of audible noise.Based on Bloch's theorem and the finite element method,the dispersion relation of the DFAM structure is calculated and verified by the transmission loss curves.The propagation characteristics of sound waves within the structure are further analyzed for noise frequencies that fall within the passband.The influence of the geometric and physical parameters on the bandgap is investigated,and the corresponding transmission loss in the propagation direction is further calculated.A hybrid collaborative design strategy,leveraging multi-parameter optimization and bandgap complementarity,is developed to construct a metastructure with continuous bandgap coverage from 20 Hz to 1000 Hz.The resulting metastructure demonstrates exceptional broadband noise attenuation,achieving a total bandgap width of 876.3 Hz(87.63% of the target range)with the transmission loss up to-762.78 d B in a three-periodic arrangement.The simulation and experimental results for the transmission loss of the DFAM metastructure show strong agreement in the low-frequency range.This work provides a novel framework for designing ultra-wide low-frequency continuous bandgap metastructures,offering significant potential for noise mitigation in complex environments.展开更多
We report an immobilized enzyme-catalyzed batch and continuous-flow synthesis of optically pure ethyl(R)-pantothenate((R)-PaOEt),the direct precursor of d-pantothenic acid.Firstly,a ketoreductase mutant designated as ...We report an immobilized enzyme-catalyzed batch and continuous-flow synthesis of optically pure ethyl(R)-pantothenate((R)-PaOEt),the direct precursor of d-pantothenic acid.Firstly,a ketoreductase mutant designated as M2,carrying two-point mutations of F97L and M242F relative to the wild-type SSCR,was constructed by site-directed mutagenesis,exhibited simultaneously improved activity toward ethyl 2′-ketopantothenate(K-PaOEt)and isopropanol,and could effectively catalyze the stereoselective reduction of K-PaOEt to(R)-PaOEt by using isopropanol as the sacrificial co-substrate to regenerate NADPH.After screening six commercially available carriers,an amino resin LXTE-700 was identified as the best solid support for the immobilization of M2 via the glutaraldehyde activation method.Upon optimization of the immobilization process and reaction conditions,the fabricated immobilized enzyme M2@amino resin demonstrated excellent recyclability and reusability,with the complete conversion of K-PaOEt to(R)-PaOEt being still realized after 12 cycles of reuse.Finally,M2@amino resin-catalyzed synthesis of(R)-PaOEt was successfully implemented in continuous-flow,accomplishing a 6.3 times higher space-time yield than that with the batch synthesis(529.2 versus 84 g L^(-1) d^(-1)).Our developed flow biocatalysis system also features an outstanding operational stability,as evidenced by the 100%conversion rate achieved after 15 consecutive days of operation.展开更多
The rapid decay of the surface wettability of plasma-treated polymers remains a critical limitation for their practical application in advanced materials.This study introduces a continuous atmospheric pressure plasma(...The rapid decay of the surface wettability of plasma-treated polymers remains a critical limitation for their practical application in advanced materials.This study introduces a continuous atmospheric pressure plasma(APP)technique for fabricating polyethylene(PE)separators with durable wettability,and elucidates the underlying mechanism.A systematic comparison of APP treatments with non-deposition and deposition gases,including Ar,Ar/O_(2),Ar/tetramethylcyclotetrasiloxane(TMCTS),and Ar/O_(2)/TMCTS,revealed the key impact factors in achieving durable wettability.Owing to the synergistic interactions of SiO_(x)C_(y)H_(z)nanoparticulate deposition,physical etching,and oxidative functionalization,the PE separator treated by Ar/O_(2)/TMCTS exhibited a 17.5-fold electrolyte wetting area compared to the original one.The improved surface energy and roughness of the SiO_(x)C_(y)H_(z)nanoparticle coating enhanced its electrochemical performance.The ionic conductivity increased by 1.9 times,while the charge transfer resistance decreased by 73.7%.Remarkably,owing to further oxidation of the SiO_(x)C_(y)H_(z)nanoparticle coating and the increase in its silica-like structure,the wetting area of the Ar/O_(2)/TMCTS-treated separator was still over 14-fold larger than that of the original separator after aging for 90 days.This study demonstrates an eco-friendly and scalable approach for fabricating high-performance battery separators and provides mechanistic insights into durable wettability by APP.展开更多
Autonomous truck platooning,as a novel transportationmode,has attracted significant attention due to its potential to improve transportation efficiency,reduce energy consumption,and lower operational costs.However,thi...Autonomous truck platooning,as a novel transportationmode,has attracted significant attention due to its potential to improve transportation efficiency,reduce energy consumption,and lower operational costs.However,this emerging mode poses new challenges to the dynamic performance of long-span bridges.This study aims to investigate the impact of autonomous truck platoons on the dynamic performance of continuous beam bridges.Using finite element software to construct accurate vehicle-bridge interaction models,we simulated the dynamic response between vehicle platoons and bridge structures.The study systematically evaluated the effects of four key factors—vehicle speed,number of formations,vehicle spacing,and vehicle weight—on mid-span deformation and the dynamic amplification factor of bridges.Taking a long-span continuous beam bridge as the research object and employing orthogonal experimental designmethods,we efficiently explored themulti-factor interactive effects on bridge dynamic response.Research results indicate that vehicle speed is the dominant factor affecting the bridge dynamic coefficient,showing a significant positive correlation.The interaction between vehicle spacing and the number of formations has a substantial impact on the dynamic coefficient,particularly under conditions of high-speed operation,large-scale formations,tight vehicle spacing,and heavy-load multi-factor coupling.These conditions can significantly increase mid-span bridge deformation and the dynamic coefficient,potentially exceeding design live-load standard value in specific scenarios.Based on the experimental results,this study recommends that truck formations strictly control vehicle speed during operation,maintain appropriate vehicle spacing,limit the number of formations,and regulate loading conditions to ensure normal bridge operation and long-termdurability.The research findings provide scientific guidance for optimizing truck formation strategies and ensuring bridge safety.展开更多
1.Introduction.Pancreaticoduodenectomy is an essential surgical procedure for the treatment of malignant tumors in the pancreatic head,distal common bile duct,and duodenal papilla,and is widely used in clinical practi...1.Introduction.Pancreaticoduodenectomy is an essential surgical procedure for the treatment of malignant tumors in the pancreatic head,distal common bile duct,and duodenal papilla,and is widely used in clinical practice.One of the primary determinants of surgical success is the durability of the pancreaticojejunal anastomosis.展开更多
The transient phenomena of re-oxidation and slag entrapment occurring in the tundish during the ladle change-over process have been proven detrimental to clean steel production.Therefore,an unsteady three-phase turbul...The transient phenomena of re-oxidation and slag entrapment occurring in the tundish during the ladle change-over process have been proven detrimental to clean steel production.Therefore,an unsteady three-phase turbulence model,coupling velocity,temperature,and phase field was established to study the effect of the ladle shroud immersion depth on the slag eye formation,slag entrainment,slag dragging,air dragging,and flow characteristics during the ladle change-over process of a two-strand tundish.The results showed that reducing the immersion depth decreases the high-velocity region area under the slag layer in the quasi-steady process.During the emptying stage,as the molten bath level gradually decreases,the outlet temperature exhibits a trend of initially decreasing and subsequently increasing across all three shroud immersion depths.However,under a 210 mm shroud immersion depth,molten slag and air are dragged into the shroud,forming slag droplets and causing significant fluctuations,with a maximum scalar velocity of 0.0764 m/s at the monitoring point.In the filling stage,air and molten slag are dragged into the molten bath,forming bubbles and slag droplets at an immersion depth of 210 mm.Bubbles are observed within the molten slag layer,which can readily cause an emulsification phenomenon,making it easier to be dragged as slag droplets.Additionally,the slag eye area measured under 210 mm immersion depth at 45 s is 0.303 m^(2),while the maximum scalar velocity of 2.4259 m/s is detected at 12 s.At an immersion depth of 360 mm,the average area of the slag eye is minimized to 0.06268 m2,with corresponding variances of 0.006753,representing the optimal immersion depth.展开更多
A full-sectional microstructure characterization method was developed to investigate the formation of coarse slag rims during the continuous casting of hypo-peritectic steel.The cross-sectional microstructural analysi...A full-sectional microstructure characterization method was developed to investigate the formation of coarse slag rims during the continuous casting of hypo-peritectic steel.The cross-sectional microstructural analysis of typical slag rims for two highly crystalline powders revealed that their formation was primarily driven by the solidification of the liquid slag.Distinct differences were observed in the microstructures of slag rims from the two powders.Powder A(characterized by a higher breaking temperature and viscosity)displayed alternating lamellar microstructures of coarse and fine phases,with the coarse phases composed of akermanite-gehlenite transition phases.In contrast,powder B(with a lower breaking temperature and viscosity)predominantly comprised regular akermanite-gehlenite crystals interspersed with a certain amount of glassy phases.Numerical simulations of a three-phase fluid flow coupled with heat transfer indicate that slag rim formation correlates with mold oscillation.Solidification of the liquid slag at the slag rim front predominantly occurs during the negative stroke of the mold oscillation.The average heating rate during the ascending stage of the mold reaches approximately 100 K·s^(−1),whereas the average cooling rate during the descending stage attains 400 K·s^(−1).This temperature variation leads to the formation of lamellar microstructures,whereas the ascending stage promotes the formation of coarse structures and thicker slag rims.Based on the powder properties,two distinct formation pathways exist for highly crystalline mold powders.For the powders with a higher breaking temperature,higher viscosity,and narrower solidification range(powder A),coarse microstructures and thicker slag rims were preferentially formed.For powders with lower breaking temperature and viscosity and wider solidification ranges(powder B),the liquid slag resisted rapid solidification,and the extended mushy zone allowed the partial liquid slag to persist at the slag rim front,promoting the formation of a thin slag rim.This study enhances the understanding of slag rim formation in highly crystalline mold powders and provides critical insights into the control of longitudinal surface cracks in hypo-peritectic steel.展开更多
Objective:To investigate the effects of switching to either Prandilin 25R monotherapy or Prandilin 25R combined with ganagliflozin proline tablets after short-term intensive continuous subcutaneous insulin infusion du...Objective:To investigate the effects of switching to either Prandilin 25R monotherapy or Prandilin 25R combined with ganagliflozin proline tablets after short-term intensive continuous subcutaneous insulin infusion during hospitalization in elderly patients with type 2 diabetes mellitus on glycemic control,glycometabolic indicators,and cardiovascular risk factors,and to evaluate the safety of the two regimens.Methods:A total of 78 elderly patients with type 2 diabetes mellitus admitted to our hospital from January 2025 to September 2025 were selected and randomly divided into a control group and an observation group,with 39 cases in each group.The control group received monotherapy with insulin lispro protamine recombinant injection(Prandilin 25R)after intensive continuous subcutaneous insulin infusion,while the observation group received Prandilin 25R combined with ganagliflozin proline tablets.Continuous glucose monitoring(CGM)was performed for 14 days during the intensive continuous subcutaneous insulin infusion therapy phase in the hospital,followed by routine fingertip blood glucose monitoring after 14 days.Glycemic control indicators,glycometabolic indicators,and the incidence of adverse reactions were compared between the two groups.Results:After treatment,the mean amplitude of glycemic excursions and the 24-hour blood glucose standard deviation were significantly lower in the observation group than in the control group,while the time spent within the target blood glucose range was significantly higher(p<0.05).The levels of glycated hemoglobin,fasting blood glucose,and 2-hour postprandial blood glucose were better in the observation group than in the control group;moreover,the body mass index,systolic blood pressure,and blood lipid levels improved more significantly in the observation group than in the control group(p<0.05).There was no statistically significant difference in the incidence of hypoglycemia between the two groups.Conclusion:Combination therapy with ganagliflozin proline tablets after short-term intensive continuous subcutaneous insulin infusion therapy can effectively improve glycemic variability in elderly patients with type 2 diabetes mellitus,with good safety.This suggests that ganagliflozin proline tablets have a hypoglycemic advantage in the combination regimen and possess high clinical promotional value.展开更多
The flow behavior of molten steel in the thin slab mold under high casting speed conditions was investigated,with a focus on the multi-mode continuous casting and rolling mold.A steel-slag two-phase flow model was est...The flow behavior of molten steel in the thin slab mold under high casting speed conditions was investigated,with a focus on the multi-mode continuous casting and rolling mold.A steel-slag two-phase flow model was established using large eddy simulation,the volume of fluid,and magnetohydrodynamics methods through numerical simulation.The maximum flow velocity and wave height at the steel-slag interface within the mold are critical evaluation criteria for analyzing asymmetric flow under varying casting speeds and electromagnetic braking.The results indicate that the asymmetric flows within the mold do not occur synchronously.The severity of the asymmetric flow correlates with the velocity difference across the steel-slag interface.A greater biased flow prolongs the time required to revert to a steady state.When the magnetic field intensity is set to 0.24 T and the magnetic pole position is at 390 mm from the steel-slag interface,this configuration can reduce the velocity of the steel-slag interface,thereby mitigating the asymmetric flow.Additionally,it can diminish the velocity,impact depth,and impact intensity on the narrow face of the jet,thus improving the distribution of velocity and turbulent kinetic energy within the mold.This configuration prolongs the time required for the steel-slag interface to transition from a stable state to its maximum velocity and shortens the time for the interface to return to stability from an unstable state.Moreover,it ensures the positional stability of the steel-slag interface,confining its position within−3 mm.展开更多
Under the background of achieving energy efficiency and carbon reduction,the use of Continuous Casting-Direct Hot Charging Rolling(CC-DHCR)technology was explored at the Hot Rolling Plant of Baosteel,China.As temperat...Under the background of achieving energy efficiency and carbon reduction,the use of Continuous Casting-Direct Hot Charging Rolling(CC-DHCR)technology was explored at the Hot Rolling Plant of Baosteel,China.As temperature variation and temperature uniformity directly affect the rolling quality of the billet,numerical simulations of the billet temperature profile changes in the CC-DHCR were conducted at the start of the industrial trial,and the billet temperature distribution and cross-section temperature difference during its transportation and throughout the heating process were analyzed.According to numerical simulation calculations,the average temperature of billet discharged from the heating furnace was 1150℃,which after subsequent controlled cooling met the final rolling temperature requirements of(880±30)℃for this kind of steel.The maximum temperature difference of the billet discharged from the furnace was within 35 K,which meets the billet heating uniformity requirements of the rolling process.The simulation results were compared with experimental results,and the rationality of the simulation was validated.In addition,the industrial trial billet was rolled,and the rolling quality was good during tracking.In this CC-DHCR industrial trial,the fuel consumption was 28.6 kgce/t(kilogram coal equivalent per ton),a reduction of 33.7%compared with the current traditional process,and CO 2 emissions were reduced by 38.09 kg/t.展开更多
Dear Editor,This letter proposes a reinforcement learning-based predictive learning algorithm for unknown continuous-time nonlinear systems with observation loss.Firstly,we construct a temporal nonzero-sum game over p...Dear Editor,This letter proposes a reinforcement learning-based predictive learning algorithm for unknown continuous-time nonlinear systems with observation loss.Firstly,we construct a temporal nonzero-sum game over predictive control input sequences,deriving multiple optimal predictive control input sequences from its solution.展开更多
China has achieved a major engineering milestone in the construction of the Beishan Underground Research Laboratory(URL)for geological disposal of high-level radioactive waste(HLW).On December 26,2025,the project team...China has achieved a major engineering milestone in the construction of the Beishan Underground Research Laboratory(URL)for geological disposal of high-level radioactive waste(HLW).On December 26,2025,the project team successfully completed the excavation of the world's first deep,continuous small-radius,steep spiral ramp by a tunnel boring machine(TBM)named Beishan No.1,which marked the completion of the underground main structure of Beishan URL.展开更多
1. Let （X, d） be a compact metric space, and denote by C0（X, X） the set of all continuous self-mappings of X with C0-topology. Let f∈C0 （X, X） and ε>0. If x,y∈X, an ε-chain from x to y is a finite sequenc...1. Let （X, d） be a compact metric space, and denote by C0（X, X） the set of all continuous self-mappings of X with C0-topology. Let f∈C0 （X, X） and ε>0. If x,y∈X, an ε-chain from x to y is a finite sequence of points {x0,…, xn} of X with x=x0, y=xn and d(f(xi-1), xi)<ε for i=1, …, n. Let CRε（x） denote the set of y∈X such that there is an ε-chain from x to y. We say x can展开更多
It is discussed in this paper that under what conditions,for a continuous domain L,there is a Scott continuous self-mapping f:L→L such that the set of fixed points fix(f)is not continuous in the ordering induced by L...It is discussed in this paper that under what conditions,for a continuous domain L,there is a Scott continuous self-mapping f:L→L such that the set of fixed points fix(f)is not continuous in the ordering induced by L.For any algebraic domain L with a countable base and a smallest element,the problem presented by Huth is partially solved.Also,an example is given and shows that there is a bounded complete domain L such that for any Scott continuous stable self-mapping f,fix(f)is not the retract of L.展开更多
BACKGROUND Continuous glucose monitoring(CGM)metrics,such as time in range(TIR)and glycemic risk index(GRI),have been linked to various diabetes-related complications,including diabetic foot(DF).AIM To investigate the...BACKGROUND Continuous glucose monitoring(CGM)metrics,such as time in range(TIR)and glycemic risk index(GRI),have been linked to various diabetes-related complications,including diabetic foot(DF).AIM To investigate the association between CGM-derived indicators and the risk of DF in individuals with type 2 diabetes mellitus(T2DM).METHODS A total of 591 individuals with T2DM(297 with DF and 294 without DF)were enrolled.Relevant clinical data,complications,comorbidities,hematological parameters,and 72-hour CGM data were collected.Logistic regression analysis was employed to examine the relationship between these measurements and the risk of DF.RESULTS Individuals with DF exhibited higher mean blood glucose(MBG)levels and increased proportions of time above range(TAR),TAR level 1,and TAR level 2,but lower TIR(all P<0.001).Patients with DF had significantly lower rates of achieving target ranges for TIR,TAR,and TAR level 2 than those without DF(all P<0.05).Logistic regression analysis revealed that GRI,MBG,and TAR level 1 were positively associated with DF risk,while TIR was inversely correlated(all P<0.05).Achieving TIR and TAR was inversely correlated with white blood cell count and glycated hemoglobin A1c levels(P<0.05).Additionally,achieving TAR was influenced by fasting plasma glucose,body mass index,diabetes duration,and antidiabetic medication use.CONCLUSION CGM metrics,particularly TIR and GRI,are significantly associated with the risk of DF in T2DM,emphasizing the importance of improved glucose control.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
During extensive gully land consolidation projects on China's Loess Plateau,many loess-bedrock fill slopes were formed,which frequently experience shallow landslides induced by rainfall.However,studies on loess-be...During extensive gully land consolidation projects on China's Loess Plateau,many loess-bedrock fill slopes were formed,which frequently experience shallow landslides induced by rainfall.However,studies on loess-bedrock slope failure triggered by continuous heavy rainfall are limited,and the role of the soilerock interface between the original bedrock slope and fill slope in the hydrological and failure process of the slope remains unclear.In this study,we conducted a continuous rainfall model test on a loess-bedrock fill slope.During the test,the responses of volume water content,pore pressure,micro deformation,and movement of the infiltration front were observed.The hydrological process and failure mechanism were then analysed.The findings suggest that the soilerock interface is a predominant infiltration surface within the slope.Rainfall infiltration rates at the interface reach 1.24-2.80 times those of the fill slope,with peak interfacial pore water pressure exceeding that of the loess fill.Furthermore,the infiltration front moves rapidly along the interface toward the bottom of the slope,reducing interfacial cohesion between bedrock and loess.The slope failure modes are summarised into three phases:local failure→flow slide and crack penetration→multistage block retrogressive slides.The cracks generated at the slope surface serve as key determinants of the geometry and scale of shallow landslides.Therefore,we recommend targeted engineering interventions to mitigate the instability and erosion of loessebedrock fill slopes.展开更多
Based on thermodynamic calculations and continuous rheological extrusion(CRE)technology,Al-Ti-V-B master alloys were designed and prepared.The morphology and the distribution of the refined phases in the master alloys...Based on thermodynamic calculations and continuous rheological extrusion(CRE)technology,Al-Ti-V-B master alloys were designed and prepared.The morphology and the distribution of the refined phases in the master alloys were analyzed by XRD,SEM,and TEM.The effects of master alloy addition and holding time on the microstructure and mechanical properties of A356 alloy were investigated.Under the optimum refiner addition of 0.3wt.%and the holding time of 20 min,the average grain size of the refined A356 alloy is 151.8±9.11μm,89.62%lower than that of original A356 alloy.The tensile strength and elongation of as-cast A356refined alloy are 196.11 MPa and 5.75%,respectively.After T6 treatment,the tensile strength and elongation of A356 refined alloy are 290.1 MPa and 3.09%,respectively.The fracture morphology is characterized by a predominance of along-crystal fracture with a small amount of through-crystal fracture,attributed to the refined grains.Finer grains promote crack path deflection and localized plastic deformation,enhancing energy dissipation and reducing the tendency for brittle fracture.This study provides a novel approach to improving the mechanical properties of A356 alloy through grain refinement using CRE Al-Ti-V-B master alloy.展开更多
Ensuring the consistent mechanical performance of three-dimensional(3D)-printed continuous fiber-reinforced composites is a significant challenge in additive manufacturing.The current reliance on manual monitoring exa...Ensuring the consistent mechanical performance of three-dimensional(3D)-printed continuous fiber-reinforced composites is a significant challenge in additive manufacturing.The current reliance on manual monitoring exacerbates this challenge by rendering the process vulnerable to environmental changes and unexpected factors,resulting in defects and inconsistent product quality,particularly in unmanned long-term operations or printing in extreme environments.To address these issues,we developed a process monitoring and closed-loop feedback control strategy for the 3D printing process.Real-time printing image data were captured and analyzed using a well-trained neural network model,and a real-time control module-enabled closed-loop feedback control of the flow rate was developed.The neural network model,which was based on image processing and artificial intelligence,enabled the recognition of flow rate values with an accuracy of 94.70%.The experimental results showed significant improvements in both the surface performance and mechanical properties of printed composites,with three to six times improvement in tensile strength and elastic modulus,demonstrating the effectiveness of the strategy.This study provides a generalized process monitoring and feedback control method for the 3D printing of continuous fiber-reinforced composites,and offers a potential solution for remote online monitoring and closed-loop adjustment in unmanned or extreme space environments.展开更多
文摘Background:Continuous care for children with enterostomy and their families has been gaining popularity in China.Objective:To evaluate the feasibility of continuous care for children with enterostomy and their families in China.Methods:The PubMed,Web of Science,Embase,Cochrane Library,EBSCO,CNKI,CBM,VIP,and WanFang were searched for clinical trials until December 30,2025.Two reviewers independently searched articles,evaluated quality and extracted data.This review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses(PRISMA).Results:33 studies involving 2774 participants were included.The meta-analysis showed that continuous care strategy can significantly reduce the incidence of complications in children with enterostomy(OR=0.20,95%CI=0.16-0.26,p<0.001,I2=0%),effectively improve the family caregiver ability for enterostomy(MD=-10.34,95%CI=-13.82 to-6.85,p<0.001,I2=99%),shorten the time for family members to replace stoma bags(MD=-13.57,95%CI=-19.66 to-7.49,p<0.001,I2=100%),and alleviate negative emotions such as anxiety(SMD=-1.80,95%CI=-2.36 to-1.23,p<0.001,I2=92%)and depression(SMD=-1.54,95%CI=-2.04 to-1.04,p<0.001,I2=89%)in the families of the affected children.Conclusions:Continuous care can reduce complications of enterostomy in children,improve the family caregiver ability for enterostomy and alleviate negative emotions of family members such as anxiety and depression.
基金Project supported by the National Natural Science Foundation of China(No.12572020)the Key Project of Natural Science Foundation of Hebei Province of China(No.A2023210064)。
文摘Local resonant acoustic metamaterials have broad applications in sound insulation,yet their single-configuration designs often exhibit limited and discontinuous bandgap widths,hindering full-frequency noise attenuation across the human auditory range.This study presents a double-phase fidget-spinner-shaped acoustic metamaterial(DFAM),specifically designed to achieve an ultra-broad,low-frequency continuous bandgap by means of synergistic structural optimization,enabling effective and robust control of audible noise.Based on Bloch's theorem and the finite element method,the dispersion relation of the DFAM structure is calculated and verified by the transmission loss curves.The propagation characteristics of sound waves within the structure are further analyzed for noise frequencies that fall within the passband.The influence of the geometric and physical parameters on the bandgap is investigated,and the corresponding transmission loss in the propagation direction is further calculated.A hybrid collaborative design strategy,leveraging multi-parameter optimization and bandgap complementarity,is developed to construct a metastructure with continuous bandgap coverage from 20 Hz to 1000 Hz.The resulting metastructure demonstrates exceptional broadband noise attenuation,achieving a total bandgap width of 876.3 Hz(87.63% of the target range)with the transmission loss up to-762.78 d B in a three-periodic arrangement.The simulation and experimental results for the transmission loss of the DFAM metastructure show strong agreement in the low-frequency range.This work provides a novel framework for designing ultra-wide low-frequency continuous bandgap metastructures,offering significant potential for noise mitigation in complex environments.
基金the Science and Technology R&D Major Project of Jiangxi Province(No.20244AFI92001)the National Natural Science Foundation of China(Nos.22071033 and 21801047)for the financial supports.
文摘We report an immobilized enzyme-catalyzed batch and continuous-flow synthesis of optically pure ethyl(R)-pantothenate((R)-PaOEt),the direct precursor of d-pantothenic acid.Firstly,a ketoreductase mutant designated as M2,carrying two-point mutations of F97L and M242F relative to the wild-type SSCR,was constructed by site-directed mutagenesis,exhibited simultaneously improved activity toward ethyl 2′-ketopantothenate(K-PaOEt)and isopropanol,and could effectively catalyze the stereoselective reduction of K-PaOEt to(R)-PaOEt by using isopropanol as the sacrificial co-substrate to regenerate NADPH.After screening six commercially available carriers,an amino resin LXTE-700 was identified as the best solid support for the immobilization of M2 via the glutaraldehyde activation method.Upon optimization of the immobilization process and reaction conditions,the fabricated immobilized enzyme M2@amino resin demonstrated excellent recyclability and reusability,with the complete conversion of K-PaOEt to(R)-PaOEt being still realized after 12 cycles of reuse.Finally,M2@amino resin-catalyzed synthesis of(R)-PaOEt was successfully implemented in continuous-flow,accomplishing a 6.3 times higher space-time yield than that with the batch synthesis(529.2 versus 84 g L^(-1) d^(-1)).Our developed flow biocatalysis system also features an outstanding operational stability,as evidenced by the 100%conversion rate achieved after 15 consecutive days of operation.
基金supported by the National Natural Science Foundation of China(No.12075054)the Fundamental Research Funds for the Central Universities(No.CUSF-DH-T-2024069)。
文摘The rapid decay of the surface wettability of plasma-treated polymers remains a critical limitation for their practical application in advanced materials.This study introduces a continuous atmospheric pressure plasma(APP)technique for fabricating polyethylene(PE)separators with durable wettability,and elucidates the underlying mechanism.A systematic comparison of APP treatments with non-deposition and deposition gases,including Ar,Ar/O_(2),Ar/tetramethylcyclotetrasiloxane(TMCTS),and Ar/O_(2)/TMCTS,revealed the key impact factors in achieving durable wettability.Owing to the synergistic interactions of SiO_(x)C_(y)H_(z)nanoparticulate deposition,physical etching,and oxidative functionalization,the PE separator treated by Ar/O_(2)/TMCTS exhibited a 17.5-fold electrolyte wetting area compared to the original one.The improved surface energy and roughness of the SiO_(x)C_(y)H_(z)nanoparticle coating enhanced its electrochemical performance.The ionic conductivity increased by 1.9 times,while the charge transfer resistance decreased by 73.7%.Remarkably,owing to further oxidation of the SiO_(x)C_(y)H_(z)nanoparticle coating and the increase in its silica-like structure,the wetting area of the Ar/O_(2)/TMCTS-treated separator was still over 14-fold larger than that of the original separator after aging for 90 days.This study demonstrates an eco-friendly and scalable approach for fabricating high-performance battery separators and provides mechanistic insights into durable wettability by APP.
基金The authors would like to thank the support by“111”Project“Centre on Safety and Intelligent Operation of Sea Bridge(D21013)”.
文摘Autonomous truck platooning,as a novel transportationmode,has attracted significant attention due to its potential to improve transportation efficiency,reduce energy consumption,and lower operational costs.However,this emerging mode poses new challenges to the dynamic performance of long-span bridges.This study aims to investigate the impact of autonomous truck platoons on the dynamic performance of continuous beam bridges.Using finite element software to construct accurate vehicle-bridge interaction models,we simulated the dynamic response between vehicle platoons and bridge structures.The study systematically evaluated the effects of four key factors—vehicle speed,number of formations,vehicle spacing,and vehicle weight—on mid-span deformation and the dynamic amplification factor of bridges.Taking a long-span continuous beam bridge as the research object and employing orthogonal experimental designmethods,we efficiently explored themulti-factor interactive effects on bridge dynamic response.Research results indicate that vehicle speed is the dominant factor affecting the bridge dynamic coefficient,showing a significant positive correlation.The interaction between vehicle spacing and the number of formations has a substantial impact on the dynamic coefficient,particularly under conditions of high-speed operation,large-scale formations,tight vehicle spacing,and heavy-load multi-factor coupling.These conditions can significantly increase mid-span bridge deformation and the dynamic coefficient,potentially exceeding design live-load standard value in specific scenarios.Based on the experimental results,this study recommends that truck formations strictly control vehicle speed during operation,maintain appropriate vehicle spacing,limit the number of formations,and regulate loading conditions to ensure normal bridge operation and long-termdurability.The research findings provide scientific guidance for optimizing truck formation strategies and ensuring bridge safety.
文摘1.Introduction.Pancreaticoduodenectomy is an essential surgical procedure for the treatment of malignant tumors in the pancreatic head,distal common bile duct,and duodenal papilla,and is widely used in clinical practice.One of the primary determinants of surgical success is the durability of the pancreaticojejunal anastomosis.
基金supported by the National Natural Science Foundation of China(Nos.52422408 and 52171031)the Liaoning Xingliao Talents-Top-notch Young Talents Project(No.XLYC2203064)+1 种基金the Excellent Youth Fund of Liaoning Natural Science Foundation(No.2023JH3/10200001)the Fundamental Research Funds for the Central Universities(No.N2425004).
文摘The transient phenomena of re-oxidation and slag entrapment occurring in the tundish during the ladle change-over process have been proven detrimental to clean steel production.Therefore,an unsteady three-phase turbulence model,coupling velocity,temperature,and phase field was established to study the effect of the ladle shroud immersion depth on the slag eye formation,slag entrainment,slag dragging,air dragging,and flow characteristics during the ladle change-over process of a two-strand tundish.The results showed that reducing the immersion depth decreases the high-velocity region area under the slag layer in the quasi-steady process.During the emptying stage,as the molten bath level gradually decreases,the outlet temperature exhibits a trend of initially decreasing and subsequently increasing across all three shroud immersion depths.However,under a 210 mm shroud immersion depth,molten slag and air are dragged into the shroud,forming slag droplets and causing significant fluctuations,with a maximum scalar velocity of 0.0764 m/s at the monitoring point.In the filling stage,air and molten slag are dragged into the molten bath,forming bubbles and slag droplets at an immersion depth of 210 mm.Bubbles are observed within the molten slag layer,which can readily cause an emulsification phenomenon,making it easier to be dragged as slag droplets.Additionally,the slag eye area measured under 210 mm immersion depth at 45 s is 0.303 m^(2),while the maximum scalar velocity of 2.4259 m/s is detected at 12 s.At an immersion depth of 360 mm,the average area of the slag eye is minimized to 0.06268 m2,with corresponding variances of 0.006753,representing the optimal immersion depth.
基金supported by the National Natural Science Foundation of China(No.52274318).
文摘A full-sectional microstructure characterization method was developed to investigate the formation of coarse slag rims during the continuous casting of hypo-peritectic steel.The cross-sectional microstructural analysis of typical slag rims for two highly crystalline powders revealed that their formation was primarily driven by the solidification of the liquid slag.Distinct differences were observed in the microstructures of slag rims from the two powders.Powder A(characterized by a higher breaking temperature and viscosity)displayed alternating lamellar microstructures of coarse and fine phases,with the coarse phases composed of akermanite-gehlenite transition phases.In contrast,powder B(with a lower breaking temperature and viscosity)predominantly comprised regular akermanite-gehlenite crystals interspersed with a certain amount of glassy phases.Numerical simulations of a three-phase fluid flow coupled with heat transfer indicate that slag rim formation correlates with mold oscillation.Solidification of the liquid slag at the slag rim front predominantly occurs during the negative stroke of the mold oscillation.The average heating rate during the ascending stage of the mold reaches approximately 100 K·s^(−1),whereas the average cooling rate during the descending stage attains 400 K·s^(−1).This temperature variation leads to the formation of lamellar microstructures,whereas the ascending stage promotes the formation of coarse structures and thicker slag rims.Based on the powder properties,two distinct formation pathways exist for highly crystalline mold powders.For the powders with a higher breaking temperature,higher viscosity,and narrower solidification range(powder A),coarse microstructures and thicker slag rims were preferentially formed.For powders with lower breaking temperature and viscosity and wider solidification ranges(powder B),the liquid slag resisted rapid solidification,and the extended mushy zone allowed the partial liquid slag to persist at the slag rim front,promoting the formation of a thin slag rim.This study enhances the understanding of slag rim formation in highly crystalline mold powders and provides critical insights into the control of longitudinal surface cracks in hypo-peritectic steel.
文摘Objective:To investigate the effects of switching to either Prandilin 25R monotherapy or Prandilin 25R combined with ganagliflozin proline tablets after short-term intensive continuous subcutaneous insulin infusion during hospitalization in elderly patients with type 2 diabetes mellitus on glycemic control,glycometabolic indicators,and cardiovascular risk factors,and to evaluate the safety of the two regimens.Methods:A total of 78 elderly patients with type 2 diabetes mellitus admitted to our hospital from January 2025 to September 2025 were selected and randomly divided into a control group and an observation group,with 39 cases in each group.The control group received monotherapy with insulin lispro protamine recombinant injection(Prandilin 25R)after intensive continuous subcutaneous insulin infusion,while the observation group received Prandilin 25R combined with ganagliflozin proline tablets.Continuous glucose monitoring(CGM)was performed for 14 days during the intensive continuous subcutaneous insulin infusion therapy phase in the hospital,followed by routine fingertip blood glucose monitoring after 14 days.Glycemic control indicators,glycometabolic indicators,and the incidence of adverse reactions were compared between the two groups.Results:After treatment,the mean amplitude of glycemic excursions and the 24-hour blood glucose standard deviation were significantly lower in the observation group than in the control group,while the time spent within the target blood glucose range was significantly higher(p<0.05).The levels of glycated hemoglobin,fasting blood glucose,and 2-hour postprandial blood glucose were better in the observation group than in the control group;moreover,the body mass index,systolic blood pressure,and blood lipid levels improved more significantly in the observation group than in the control group(p<0.05).There was no statistically significant difference in the incidence of hypoglycemia between the two groups.Conclusion:Combination therapy with ganagliflozin proline tablets after short-term intensive continuous subcutaneous insulin infusion therapy can effectively improve glycemic variability in elderly patients with type 2 diabetes mellitus,with good safety.This suggests that ganagliflozin proline tablets have a hypoglycemic advantage in the combination regimen and possess high clinical promotional value.
基金support from the National Natural Science Foundation of China(Grant Nos.52174313 and 52304350)thank all members of the Hebei High Quality Steel Continuous Casting Engineering Technology Research Center at North China University of Science and Technology,Tangshan,China.
文摘The flow behavior of molten steel in the thin slab mold under high casting speed conditions was investigated,with a focus on the multi-mode continuous casting and rolling mold.A steel-slag two-phase flow model was established using large eddy simulation,the volume of fluid,and magnetohydrodynamics methods through numerical simulation.The maximum flow velocity and wave height at the steel-slag interface within the mold are critical evaluation criteria for analyzing asymmetric flow under varying casting speeds and electromagnetic braking.The results indicate that the asymmetric flows within the mold do not occur synchronously.The severity of the asymmetric flow correlates with the velocity difference across the steel-slag interface.A greater biased flow prolongs the time required to revert to a steady state.When the magnetic field intensity is set to 0.24 T and the magnetic pole position is at 390 mm from the steel-slag interface,this configuration can reduce the velocity of the steel-slag interface,thereby mitigating the asymmetric flow.Additionally,it can diminish the velocity,impact depth,and impact intensity on the narrow face of the jet,thus improving the distribution of velocity and turbulent kinetic energy within the mold.This configuration prolongs the time required for the steel-slag interface to transition from a stable state to its maximum velocity and shortens the time for the interface to return to stability from an unstable state.Moreover,it ensures the positional stability of the steel-slag interface,confining its position within−3 mm.
文摘Under the background of achieving energy efficiency and carbon reduction,the use of Continuous Casting-Direct Hot Charging Rolling(CC-DHCR)technology was explored at the Hot Rolling Plant of Baosteel,China.As temperature variation and temperature uniformity directly affect the rolling quality of the billet,numerical simulations of the billet temperature profile changes in the CC-DHCR were conducted at the start of the industrial trial,and the billet temperature distribution and cross-section temperature difference during its transportation and throughout the heating process were analyzed.According to numerical simulation calculations,the average temperature of billet discharged from the heating furnace was 1150℃,which after subsequent controlled cooling met the final rolling temperature requirements of(880±30)℃for this kind of steel.The maximum temperature difference of the billet discharged from the furnace was within 35 K,which meets the billet heating uniformity requirements of the rolling process.The simulation results were compared with experimental results,and the rationality of the simulation was validated.In addition,the industrial trial billet was rolled,and the rolling quality was good during tracking.In this CC-DHCR industrial trial,the fuel consumption was 28.6 kgce/t(kilogram coal equivalent per ton),a reduction of 33.7%compared with the current traditional process,and CO 2 emissions were reduced by 38.09 kg/t.
基金supported by the National Natural Science Foundation of China(62433014,62373287,62573324,62333005,62273255)in part by the International Exchange Program for Graduate Students of Tongji University(4360143306)+3 种基金in part by the Fundamental Research Funds for Central Universities(22120230311)supported by DeutscheForschungsgemeinschaft(DFG,German Research Foundation)under Germany’s Excellence Strategy(EXC 2075390740016,468094890)support by the Stuttgart Center for Simulation Science(SimTech)the International Max Planck Research School for Intelligent Systems(IMPRS-IS)for supporting Y.Xie。
文摘Dear Editor,This letter proposes a reinforcement learning-based predictive learning algorithm for unknown continuous-time nonlinear systems with observation loss.Firstly,we construct a temporal nonzero-sum game over predictive control input sequences,deriving multiple optimal predictive control input sequences from its solution.
文摘China has achieved a major engineering milestone in the construction of the Beishan Underground Research Laboratory(URL)for geological disposal of high-level radioactive waste(HLW).On December 26,2025,the project team successfully completed the excavation of the world's first deep,continuous small-radius,steep spiral ramp by a tunnel boring machine(TBM)named Beishan No.1,which marked the completion of the underground main structure of Beishan URL.
基金Project supported in part by the Foundation of Zhongshan University Advanced Research Centre.
文摘1. Let （X, d） be a compact metric space, and denote by C0（X, X） the set of all continuous self-mappings of X with C0-topology. Let f∈C0 （X, X） and ε>0. If x,y∈X, an ε-chain from x to y is a finite sequence of points {x0,…, xn} of X with x=x0, y=xn and d(f(xi-1), xi)<ε for i=1, …, n. Let CRε（x） denote the set of y∈X such that there is an ε-chain from x to y. We say x can
基金Supported by the National Natural Science Foundation of China(Grant No.10571112)the National Key Project of Fundamental Research(Grant No.2002CB312200)
文摘It is discussed in this paper that under what conditions,for a continuous domain L,there is a Scott continuous self-mapping f:L→L such that the set of fixed points fix(f)is not continuous in the ordering induced by L.For any algebraic domain L with a countable base and a smallest element,the problem presented by Huth is partially solved.Also,an example is given and shows that there is a bounded complete domain L such that for any Scott continuous stable self-mapping f,fix(f)is not the retract of L.
基金Supported by Yunnan Province Academician(Expert)Workstation Project,No.202305AF150097the Basic Research Program of Yunnan Province(Kunming Medical University Joint Special Project),No.202101AY070001-276+3 种基金the National Natural Science Foundation of China,No.82160159the Key Project Program of Yunnan Province(Kunming Medical University Joint Special Project),No.202301AY070001-013the Major Science and Technology Project of Yunnan Province,No.202202AA100004the Double First-class University Construction Project of Yunnan University,No.CY22624106.
文摘BACKGROUND Continuous glucose monitoring(CGM)metrics,such as time in range(TIR)and glycemic risk index(GRI),have been linked to various diabetes-related complications,including diabetic foot(DF).AIM To investigate the association between CGM-derived indicators and the risk of DF in individuals with type 2 diabetes mellitus(T2DM).METHODS A total of 591 individuals with T2DM(297 with DF and 294 without DF)were enrolled.Relevant clinical data,complications,comorbidities,hematological parameters,and 72-hour CGM data were collected.Logistic regression analysis was employed to examine the relationship between these measurements and the risk of DF.RESULTS Individuals with DF exhibited higher mean blood glucose(MBG)levels and increased proportions of time above range(TAR),TAR level 1,and TAR level 2,but lower TIR(all P<0.001).Patients with DF had significantly lower rates of achieving target ranges for TIR,TAR,and TAR level 2 than those without DF(all P<0.05).Logistic regression analysis revealed that GRI,MBG,and TAR level 1 were positively associated with DF risk,while TIR was inversely correlated(all P<0.05).Achieving TIR and TAR was inversely correlated with white blood cell count and glycated hemoglobin A1c levels(P<0.05).Additionally,achieving TAR was influenced by fasting plasma glucose,body mass index,diabetes duration,and antidiabetic medication use.CONCLUSION CGM metrics,particularly TIR and GRI,are significantly associated with the risk of DF in T2DM,emphasizing the importance of improved glucose control.
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.
基金supported by the National Key R&D Program of China(Grant No.2023YFC3008404)the National Key Research and Development Program,China(Grant No.2017YFD0800501)the National Natural Science Foundation of China(No.41790443).
文摘During extensive gully land consolidation projects on China's Loess Plateau,many loess-bedrock fill slopes were formed,which frequently experience shallow landslides induced by rainfall.However,studies on loess-bedrock slope failure triggered by continuous heavy rainfall are limited,and the role of the soilerock interface between the original bedrock slope and fill slope in the hydrological and failure process of the slope remains unclear.In this study,we conducted a continuous rainfall model test on a loess-bedrock fill slope.During the test,the responses of volume water content,pore pressure,micro deformation,and movement of the infiltration front were observed.The hydrological process and failure mechanism were then analysed.The findings suggest that the soilerock interface is a predominant infiltration surface within the slope.Rainfall infiltration rates at the interface reach 1.24-2.80 times those of the fill slope,with peak interfacial pore water pressure exceeding that of the loess fill.Furthermore,the infiltration front moves rapidly along the interface toward the bottom of the slope,reducing interfacial cohesion between bedrock and loess.The slope failure modes are summarised into three phases:local failure→flow slide and crack penetration→multistage block retrogressive slides.The cracks generated at the slope surface serve as key determinants of the geometry and scale of shallow landslides.Therefore,we recommend targeted engineering interventions to mitigate the instability and erosion of loessebedrock fill slopes.
基金supported by the National Key Research and Development Program of China (Grant No.2022YFB3706801)the National Natural Science Foundation of China (Grant Nos.U2341253,52371019,U2241232)+2 种基金the Dalian High-level Talents Innovation Support Program (Grant No.2021RD06)the Applied Basic Research Program of Liaoning Province (Grant No.2022JH2/101300003)the Natural Science Foundation of Liaoning Province (Grant Nos.2022-BS-262,JYTMS20230031)。
文摘Based on thermodynamic calculations and continuous rheological extrusion(CRE)technology,Al-Ti-V-B master alloys were designed and prepared.The morphology and the distribution of the refined phases in the master alloys were analyzed by XRD,SEM,and TEM.The effects of master alloy addition and holding time on the microstructure and mechanical properties of A356 alloy were investigated.Under the optimum refiner addition of 0.3wt.%and the holding time of 20 min,the average grain size of the refined A356 alloy is 151.8±9.11μm,89.62%lower than that of original A356 alloy.The tensile strength and elongation of as-cast A356refined alloy are 196.11 MPa and 5.75%,respectively.After T6 treatment,the tensile strength and elongation of A356 refined alloy are 290.1 MPa and 3.09%,respectively.The fracture morphology is characterized by a predominance of along-crystal fracture with a small amount of through-crystal fracture,attributed to the refined grains.Finer grains promote crack path deflection and localized plastic deformation,enhancing energy dissipation and reducing the tendency for brittle fracture.This study provides a novel approach to improving the mechanical properties of A356 alloy through grain refinement using CRE Al-Ti-V-B master alloy.
基金supported by National Key Research and Development Program of China(Grant No.2023YFB4604100)National Key Research and Development Program of China(Grant No.2022YFB3806104)+4 种基金Key Research and Development Program in Shaanxi Province(Grant No.2021LLRH-08-17)Young Elite Scientists Sponsorship Program by CAST(No.2023QNRC001)K C Wong Education Foundation of ChinaYouth Innovation Team of Shaanxi Universities of ChinaKey Research and Development Program of Shaanxi Province(Grant 2021LLRH-08-3.1).
文摘Ensuring the consistent mechanical performance of three-dimensional(3D)-printed continuous fiber-reinforced composites is a significant challenge in additive manufacturing.The current reliance on manual monitoring exacerbates this challenge by rendering the process vulnerable to environmental changes and unexpected factors,resulting in defects and inconsistent product quality,particularly in unmanned long-term operations or printing in extreme environments.To address these issues,we developed a process monitoring and closed-loop feedback control strategy for the 3D printing process.Real-time printing image data were captured and analyzed using a well-trained neural network model,and a real-time control module-enabled closed-loop feedback control of the flow rate was developed.The neural network model,which was based on image processing and artificial intelligence,enabled the recognition of flow rate values with an accuracy of 94.70%.The experimental results showed significant improvements in both the surface performance and mechanical properties of printed composites,with three to six times improvement in tensile strength and elastic modulus,demonstrating the effectiveness of the strategy.This study provides a generalized process monitoring and feedback control method for the 3D printing of continuous fiber-reinforced composites,and offers a potential solution for remote online monitoring and closed-loop adjustment in unmanned or extreme space environments.
