Basic concepts of seismic zonation in Russia are the degree of intensity and soil categories that correspond to discrete structure in the ratio “seismic impact-ground reaction”. Meanwhile, the parameters of seismic ...Basic concepts of seismic zonation in Russia are the degree of intensity and soil categories that correspond to discrete structure in the ratio “seismic impact-ground reaction”. Meanwhile, the parameters of seismic effects, and the parameters of soil properties are continuous in the space. The report expounds the basic theory, adequately representing the above mentioned continuality. Thus, many the concepts of seismic zonation, used now, become either more correct, or unnecessary.展开更多
This study investigated the effects of xu-argument-based continuation writing on learners’processing of source texts.Seventy-five participants were randomly assigned to three conditions:(1)continuation writing,(2)sum...This study investigated the effects of xu-argument-based continuation writing on learners’processing of source texts.Seventy-five participants were randomly assigned to three conditions:(1)continuation writing,(2)summary writing,or(3)reading comprehension.Eye-tracking data were collected during reading,measuring early(first fixation duration,first pass duration)and late(go-past time,total fixation duration)eye movements.During writing,source-text rereading was tracked via fixation counts and durations.Results showed that task type did not affect initial lexical access,as first fixation duration showed no group differences.However,both production groups exhibited significantly longer first pass durations than the reading comprehension group.Late measures revealed a gradient pattern:the continuation writing group spent significantly longer gopast time and total fixation duration than the summary writing group,which exceeded the reading comprehension group.This indicates that continuation tasks promoted deeper cognitive engagement during reading.During writing,the continuation writing group spent more time rereading the source text with higher fixation counts than the summary writing group.These findings suggest that continuation writing triggers more intensive reader-text interaction during pre-writing and enhances comprehension-production coupling through sustained attention to input during writing.This study sheds light on the cognitive mechanisms underlying the theoretical and pedagogical value of xu-argument.展开更多
BACKGROUND:This study is to evaluate clearance eff ects of hemoperfusion(HP),continuous renal replacement therapy(CRRT),and plasma exchange(PE)for chlorfenapyr and its metabolite tralopyril in patients with acute pois...BACKGROUND:This study is to evaluate clearance eff ects of hemoperfusion(HP),continuous renal replacement therapy(CRRT),and plasma exchange(PE)for chlorfenapyr and its metabolite tralopyril in patients with acute poisoning.METHODS:This retrospective study included 18 patients with acute oral chlorfenapyr poisoning treated at our department between January 2022 and January 2024.All patients received conventional therapies combined with blood purification,including HP,CRRT,and PE.HP was performed three sessions within the fi rst 24 h,followed by CRRT and PE.Serial blood samples were collected to measure plasma concentrations of chlorfenapyr and tralopyril using gas chromatography/liquid chromatography-mass spectrometry(GC/LC-MS).The toxin-clearance eff ects were assessed using a linear mixed-eff ects(LME)model.RESULTS:The hourly decline rate of the plasma chlorfenapyr concentration(median[IQR])was 8.83%(1.79%)for HP,4.12%(1.26%)for CRRT,and 6.85%(1.44%)for PE.LME analysis showed higher decline rate in the plasma concentration with HP(β=5.00;P<0.001)and PE(β=2.15;P=0.003)compared to CRRT.For tralopyril,the hourly decline rates were 3.04%(0.62%)for HP,1.82%(0.48%)for CRRT,and 3.01%(0.37%)for PE.LME analysis showed that the clearance effects of HP(β=0.027;P<0.001)and PE(β=0.022;P=0.001)were superior to CRRT.Pre-treatment toxin levels and the interval from hospital admission to blood purifi cation showed no signifi cant interaction with clearance outcomes.CONCLUSION:In our study,HP was associated with a higher decline rate in plasma chlorfenapyr concentration compared to CRRT and PE,supporting HP as a preferred early intervention.However,all three methods showed limited effi cacy in reducing tralopyril levels.Further research into the toxicokinetics and mechanisms of chlorfenapyr is warranted to optimize purifi cation strategies.展开更多
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
Introduction:The choice is no longer whether—but when and how!Today,organizations can no longer choose whether or not to engage with stakeholders;the only real decision is when and how to do it successfully.Engaging ...Introduction:The choice is no longer whether—but when and how!Today,organizations can no longer choose whether or not to engage with stakeholders;the only real decision is when and how to do it successfully.Engaging stakeholders is essential for any type of organization,public,private,or civil society.In fact,it is a fundamental part of effective governance,continuous improvement,and social responsibility.The principle behind stakeholder engagement is simple yet powerful:those who can influence or be affected by an organization's mission must be given the opportunity to express their views and contribute to shaping the decisions that impact them.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
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
Mental-health risk detection seeks early signs of distress from social media posts and clinical transcripts to enable timely intervention before crises.When such risks go undetected,consequences can escalate to self-h...Mental-health risk detection seeks early signs of distress from social media posts and clinical transcripts to enable timely intervention before crises.When such risks go undetected,consequences can escalate to self-harm,long-term disability,reduced productivity,and significant societal and economic burden.Despite recent advances,detecting risk from online text remains challenging due to heterogeneous language,evolving semantics,and the sequential emergence of new datasets.Effective solutions must encode clinically meaningful cues,reason about causal relations,and adapt to new domains without forgetting prior knowledge.To address these challenges,this paper presents a Continual Neuro-Symbolic Graph Learning(CNSGL)framework that unifies symbolic reasoning,causal inference,and continual learning within a single architecture.Each post is represented as a symbolic graph linking clinically relevant tags to textual content,enriched with causal edges derived from directional Point-wise Mutual Information(PMI).A two-layer Graph Convolutional Network(GCN)encodes these graphs,and a Transformer-based attention pooler aggregates node embeddings while providing interpretable tag-level importances.Continual adaptation across datasets is achieved through the Multi-Head Freeze(MH-Freeze)strategy,which freezes a shared encoder and incrementally trains lightweight task-specific heads(small classifiers attached to the shared embedding).Experimental evaluations across six diverse mental-health datasets ranging from Reddit discourse to clinical interviews,demonstrate that MH-Freeze consistently outperforms existing continual-learning baselines in both discriminative accuracy and calibration reliability.Across six datasets,MH-Freeze achieves up to 0.925 accuracy and 0.923 F1-Score,with AUPRC≥0.934 and AUROC≥0.942,consistently surpassing all continual-learning baselines.The results confirm the framework’s ability to preserve prior knowledge,adapt to domain shifts,and maintain causal interpretability,establishing CNSGL as a promising step toward robust,explainable,and lifelong mental-health risk assessment.展开更多
This study investigated the impact of the xu-argument-based continuation on Chinese high school students’English syntactic complexity captured using verb-argument constructions(VACs)over an 8-week period.Participants...This study investigated the impact of the xu-argument-based continuation on Chinese high school students’English syntactic complexity captured using verb-argument constructions(VACs)over an 8-week period.Participants were two comparable groups of students:one group worked with English input texts(i.e.,E-E),while the other worked with Chinese input texts with the same content(i.e.,C-E).The results showed that over time,the E-E group exhibited a greater tendency to use a wider range of VACs,such as caused-motion constructions,attributives,passives,and phrasal verbs.At the same time,they reduced their use of simpler VACs like intransitive-motion and simple transitive constructions,especially when compared to the C-E group.This pattern was also evident in the topic-based writing during the posttest.These findings strongly support the effectiveness of xu-argument-based continuation tasks in promoting the development of L2 VAC knowledge.They suggest that tasks combining language input with output can significantly enhance learners’ability to use more sophisticated VACs.展开更多
This paper deals with the numerical solutions of two-dimensional(2D)semi-linear reaction-diffusion equations(SLRDEs)with piecewise continuous argument(PCA)in reaction term.A high-order compact difference method called...This paper deals with the numerical solutions of two-dimensional(2D)semi-linear reaction-diffusion equations(SLRDEs)with piecewise continuous argument(PCA)in reaction term.A high-order compact difference method called Ⅰ-type basic scheme is developed for solving the equations and it is proved under the suitable conditions that this method has the computational accuracy O(τ^(2)+h_(x)^(4)+h_(y)^(4)),where τ,h_(x )and h_(y) are the calculation stepsizes of the method in t-,x-and y-direction,respectively.With the above method and Newton linearized technique,a Ⅱ-type basic scheme is also suggested.Based on the both basic schemes,the corresponding Ⅰ-and Ⅱ-type alternating direction implicit(ADI)schemes are derived.Finally,with a series of numerical experiments,the computational accuracy and efficiency of the four numerical schemes are further illustrated.展开更多
China Standardization:What is your view on this year's International Standardization Youth Star Competition?Tom Heilandt:This is the first time I have attended this event,which was founded by my good friend Dr.Zha...China Standardization:What is your view on this year's International Standardization Youth Star Competition?Tom Heilandt:This is the first time I have attended this event,which was founded by my good friend Dr.Zhang Xiaogang,whom I first met in 2016 when he was President of ISO.It is an excellent initiative.I strongly believe that it is essential for young people to become involved in standardization.展开更多
This paper highlights the crucial role of Indonesia’s GNSS receiver network in advancing Equatorial Plasma Bubble(EPB)studies in Southeast and East Asia,as ionospheric irregularities within EPB can disrupt GNSS signa...This paper highlights the crucial role of Indonesia’s GNSS receiver network in advancing Equatorial Plasma Bubble(EPB)studies in Southeast and East Asia,as ionospheric irregularities within EPB can disrupt GNSS signals and degrade positioning accuracy.Managed by the Indonesian Geospatial Information Agency(BIG),the Indonesia Continuously Operating Reference Station(Ina-CORS)network comprises over 300 GNSS receivers spanning equatorial to southern low-latitude regions.Ina-CORS is uniquely situated to monitor EPB generation,zonal drift,and dissipation across Southeast Asia.We provide a practical tool for EPB research,by sharing two-dimensional rate of Total Electron Content(TEC)change index(ROTI)derived from this network.We generate ROTI maps with a 10-minute resolution,and samples from May 2024 are publicly available for further scientific research.Two preliminary findings from the ROTI maps of Ina-CORS are noteworthy.First,the Ina-CORS ROTI maps reveal that the irregularities within a broader EPB structure persist longer,increasing the potential for these irregularities to migrate farther eastward.Second,we demonstrate that combined ROTI maps from Ina-CORS and GNSS receivers in East Asia and Australia can be used to monitor the development of ionospheric irregularities in Southeast and East Asia.We have demonstrated the combined ROTI maps to capture the development of ionospheric irregularities in the Southeast/East Asian sector during the G5 Geomagnetic Storm on May 11,2024.We observed simultaneous ionospheric irregularities in Japan and Australia,respectively propagating northwestward and southwestward,before midnight,whereas Southeast Asia’s equatorial and low-latitude regions exhibited irregularities post-midnight.By sharing ROTI maps from Indonesia and integrating them with regional GNSS networks,researchers can conduct comprehensive EPB studies,enhancing the understanding of EPB behavior across Southeast and East Asia and contributing significantly to ionospheric research.展开更多
Diabetes is highly prevalent among the elderly worldwide,with the highest number of diabetes cases in China.Yet,the management of diabetes remains unsatisfactory.Recent advances in digital health technologies have fac...Diabetes is highly prevalent among the elderly worldwide,with the highest number of diabetes cases in China.Yet,the management of diabetes remains unsatisfactory.Recent advances in digital health technologies have facilitated the establishment of smart wards for diabetes patients.There is a lack of smart wards tailored specifically for older diabetes patients who encounter unique challenges in glycemic control and diabetes management,including an increased vulnerability to hypoglycemia,the presence of multiple chronic diseases,and cognitive decline.In this review,studies on digital health technologies for diabetes in China and beyond were summarized to elucidate how the adoption of digital health technologies,such as real-time continuous glucose monitoring,sensor-augmented pump technology,and their integration with 5th generation networks,big data cloud storage,and hospital information systems,can address issues specifically related to elderly diabetes patients in hospital wards.Furthermore,the challenges and future directions for establishing and implementing smart wards for elderly diabetes patients are discussed,and these challenges may also be applicable to other countries worldwide,not just in China.Taken together,the smart wards may enhance clinical outcomes,address specific issues,and eventually improve patient-centered hospital care for elderly patients with diabetes.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
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
Radio frequency(RF)cavities for advanced storage rings,also known as diffraction-limited storage rings,are under development.To this end,a competitive and promising approach involves normal-conducting continuous wave ...Radio frequency(RF)cavities for advanced storage rings,also known as diffraction-limited storage rings,are under development.To this end,a competitive and promising approach involves normal-conducting continuous wave technology.The design and preliminary test of a 499.654 MHz RF cavity for the Wuhan Advanced Light Source(WALS)based on specific beam parameters were conducted at the SSRF.Multi-objective evolutionary algorithms have been utilized to optimize RF properties,such as the power loss and power density,resulting in better performance in the continuous wave mode.Further improvements were made to suppress multipacting effects in the working area.To operate stably with the beam,higher-order mode dampers were applied to better address the coupling bunch instability than in previous designs,along with thermal analysis to achieve the desired RF performance.Comprehensive simulation studies demonstrated the stable operation of the RF cavity at the defined beam parameters in the WALS design.A prototype RF cavity was then developed,and the RF performance results in a low-power test showed good agreement with the design and simulation,exhibiting readiness for high-power experiments and operation.展开更多
In GNSS denied environments,pseudolites have to rely on prior information,such as ground anchoring points,terrain matching or other multi-source means for positioning.This paper proposes a method of dynamic networking...In GNSS denied environments,pseudolites have to rely on prior information,such as ground anchoring points,terrain matching or other multi-source means for positioning.This paper proposes a method of dynamic networking of UAVs pseudolites for accurate navigation with only inertial navigation during GNSS denied area,which can provide accurate positioning services without prior information like anchor points.On this basis,this paper proposes a mathematical model of UAV pseudolite networking to describe the relationship of UAV flight altitude,network service coverage and anti-jamming capabilities.This model demonstrates excellent anti-interference ability,which can achieve a maximum power enhancement of up to 54.58 dB.And it can also offer another operating mode with a maximum coverage range of up to 2675.47 km^(2),while still ensuring a power enhancement of 37.57dB.This method can effectively solve the problem of providing continuous positioning services as an alternative GNSS,and is also a powerful support solution for resilient Positioning,Navigation,and Timing(PNT)^([1]).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Basic concepts of seismic zonation in Russia are the degree of intensity and soil categories that correspond to discrete structure in the ratio “seismic impact-ground reaction”. Meanwhile, the parameters of seismic effects, and the parameters of soil properties are continuous in the space. The report expounds the basic theory, adequately representing the above mentioned continuality. Thus, many the concepts of seismic zonation, used now, become either more correct, or unnecessary.
文摘This study investigated the effects of xu-argument-based continuation writing on learners’processing of source texts.Seventy-five participants were randomly assigned to three conditions:(1)continuation writing,(2)summary writing,or(3)reading comprehension.Eye-tracking data were collected during reading,measuring early(first fixation duration,first pass duration)and late(go-past time,total fixation duration)eye movements.During writing,source-text rereading was tracked via fixation counts and durations.Results showed that task type did not affect initial lexical access,as first fixation duration showed no group differences.However,both production groups exhibited significantly longer first pass durations than the reading comprehension group.Late measures revealed a gradient pattern:the continuation writing group spent significantly longer gopast time and total fixation duration than the summary writing group,which exceeded the reading comprehension group.This indicates that continuation tasks promoted deeper cognitive engagement during reading.During writing,the continuation writing group spent more time rereading the source text with higher fixation counts than the summary writing group.These findings suggest that continuation writing triggers more intensive reader-text interaction during pre-writing and enhances comprehension-production coupling through sustained attention to input during writing.This study sheds light on the cognitive mechanisms underlying the theoretical and pedagogical value of xu-argument.
基金funded by the Medical Science Research Project of the Hebei Provincial Health and Health Commission(20230550).
文摘BACKGROUND:This study is to evaluate clearance eff ects of hemoperfusion(HP),continuous renal replacement therapy(CRRT),and plasma exchange(PE)for chlorfenapyr and its metabolite tralopyril in patients with acute poisoning.METHODS:This retrospective study included 18 patients with acute oral chlorfenapyr poisoning treated at our department between January 2022 and January 2024.All patients received conventional therapies combined with blood purification,including HP,CRRT,and PE.HP was performed three sessions within the fi rst 24 h,followed by CRRT and PE.Serial blood samples were collected to measure plasma concentrations of chlorfenapyr and tralopyril using gas chromatography/liquid chromatography-mass spectrometry(GC/LC-MS).The toxin-clearance eff ects were assessed using a linear mixed-eff ects(LME)model.RESULTS:The hourly decline rate of the plasma chlorfenapyr concentration(median[IQR])was 8.83%(1.79%)for HP,4.12%(1.26%)for CRRT,and 6.85%(1.44%)for PE.LME analysis showed higher decline rate in the plasma concentration with HP(β=5.00;P<0.001)and PE(β=2.15;P=0.003)compared to CRRT.For tralopyril,the hourly decline rates were 3.04%(0.62%)for HP,1.82%(0.48%)for CRRT,and 3.01%(0.37%)for PE.LME analysis showed that the clearance effects of HP(β=0.027;P<0.001)and PE(β=0.022;P=0.001)were superior to CRRT.Pre-treatment toxin levels and the interval from hospital admission to blood purifi cation showed no signifi cant interaction with clearance outcomes.CONCLUSION:In our study,HP was associated with a higher decline rate in plasma chlorfenapyr concentration compared to CRRT and PE,supporting HP as a preferred early intervention.However,all three methods showed limited effi cacy in reducing tralopyril levels.Further research into the toxicokinetics and mechanisms of chlorfenapyr is warranted to optimize purifi cation strategies.
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.
文摘Introduction:The choice is no longer whether—but when and how!Today,organizations can no longer choose whether or not to engage with stakeholders;the only real decision is when and how to do it successfully.Engaging stakeholders is essential for any type of organization,public,private,or civil society.In fact,it is a fundamental part of effective governance,continuous improvement,and social responsibility.The principle behind stakeholder engagement is simple yet powerful:those who can influence or be affected by an organization's mission must be given the opportunity to express their views and contribute to shaping the decisions that impact them.
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.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.
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korea government(MSIT)(RS-2025-00518960)in part by the National Research Foundation of Korea(NRF)grant funded by the Korea government(MSIT)(RS-2025-00563192).
文摘Mental-health risk detection seeks early signs of distress from social media posts and clinical transcripts to enable timely intervention before crises.When such risks go undetected,consequences can escalate to self-harm,long-term disability,reduced productivity,and significant societal and economic burden.Despite recent advances,detecting risk from online text remains challenging due to heterogeneous language,evolving semantics,and the sequential emergence of new datasets.Effective solutions must encode clinically meaningful cues,reason about causal relations,and adapt to new domains without forgetting prior knowledge.To address these challenges,this paper presents a Continual Neuro-Symbolic Graph Learning(CNSGL)framework that unifies symbolic reasoning,causal inference,and continual learning within a single architecture.Each post is represented as a symbolic graph linking clinically relevant tags to textual content,enriched with causal edges derived from directional Point-wise Mutual Information(PMI).A two-layer Graph Convolutional Network(GCN)encodes these graphs,and a Transformer-based attention pooler aggregates node embeddings while providing interpretable tag-level importances.Continual adaptation across datasets is achieved through the Multi-Head Freeze(MH-Freeze)strategy,which freezes a shared encoder and incrementally trains lightweight task-specific heads(small classifiers attached to the shared embedding).Experimental evaluations across six diverse mental-health datasets ranging from Reddit discourse to clinical interviews,demonstrate that MH-Freeze consistently outperforms existing continual-learning baselines in both discriminative accuracy and calibration reliability.Across six datasets,MH-Freeze achieves up to 0.925 accuracy and 0.923 F1-Score,with AUPRC≥0.934 and AUROC≥0.942,consistently surpassing all continual-learning baselines.The results confirm the framework’s ability to preserve prior knowledge,adapt to domain shifts,and maintain causal interpretability,establishing CNSGL as a promising step toward robust,explainable,and lifelong mental-health risk assessment.
文摘This study investigated the impact of the xu-argument-based continuation on Chinese high school students’English syntactic complexity captured using verb-argument constructions(VACs)over an 8-week period.Participants were two comparable groups of students:one group worked with English input texts(i.e.,E-E),while the other worked with Chinese input texts with the same content(i.e.,C-E).The results showed that over time,the E-E group exhibited a greater tendency to use a wider range of VACs,such as caused-motion constructions,attributives,passives,and phrasal verbs.At the same time,they reduced their use of simpler VACs like intransitive-motion and simple transitive constructions,especially when compared to the C-E group.This pattern was also evident in the topic-based writing during the posttest.These findings strongly support the effectiveness of xu-argument-based continuation tasks in promoting the development of L2 VAC knowledge.They suggest that tasks combining language input with output can significantly enhance learners’ability to use more sophisticated VACs.
文摘This paper deals with the numerical solutions of two-dimensional(2D)semi-linear reaction-diffusion equations(SLRDEs)with piecewise continuous argument(PCA)in reaction term.A high-order compact difference method called Ⅰ-type basic scheme is developed for solving the equations and it is proved under the suitable conditions that this method has the computational accuracy O(τ^(2)+h_(x)^(4)+h_(y)^(4)),where τ,h_(x )and h_(y) are the calculation stepsizes of the method in t-,x-and y-direction,respectively.With the above method and Newton linearized technique,a Ⅱ-type basic scheme is also suggested.Based on the both basic schemes,the corresponding Ⅰ-and Ⅱ-type alternating direction implicit(ADI)schemes are derived.Finally,with a series of numerical experiments,the computational accuracy and efficiency of the four numerical schemes are further illustrated.
文摘China Standardization:What is your view on this year's International Standardization Youth Star Competition?Tom Heilandt:This is the first time I have attended this event,which was founded by my good friend Dr.Zhang Xiaogang,whom I first met in 2016 when he was President of ISO.It is an excellent initiative.I strongly believe that it is essential for young people to become involved in standardization.
基金JSPS KAKENHI Grant Number16H06286 supports global GNSS ionospheric maps (TEC,ROTI,and detrended TEC maps) developed by the Institute for SpaceEarth Environmental Research (ISEE) of Nagoya Universitysupport of the 2024 JASSO Follow-up Research Fellowship Program for a 90-day visiting research at the Institute for Space-Earth Environmental Research (ISEE),Nagoya University+3 种基金the support received from Telkom University under the“Skema Penelitian Terapan Periode I Tahun Anggaran 2024”the Memorandum of Understanding for Research Collaboration on Regional Ionospheric Observation (No:092/SAM3/TE-DEK/2021)the National Institute of Information and Communications Technology (NICT) International Exchange Program 2024-2025(No.2024-007)support for a one-year visiting research at Hokkaido University
文摘This paper highlights the crucial role of Indonesia’s GNSS receiver network in advancing Equatorial Plasma Bubble(EPB)studies in Southeast and East Asia,as ionospheric irregularities within EPB can disrupt GNSS signals and degrade positioning accuracy.Managed by the Indonesian Geospatial Information Agency(BIG),the Indonesia Continuously Operating Reference Station(Ina-CORS)network comprises over 300 GNSS receivers spanning equatorial to southern low-latitude regions.Ina-CORS is uniquely situated to monitor EPB generation,zonal drift,and dissipation across Southeast Asia.We provide a practical tool for EPB research,by sharing two-dimensional rate of Total Electron Content(TEC)change index(ROTI)derived from this network.We generate ROTI maps with a 10-minute resolution,and samples from May 2024 are publicly available for further scientific research.Two preliminary findings from the ROTI maps of Ina-CORS are noteworthy.First,the Ina-CORS ROTI maps reveal that the irregularities within a broader EPB structure persist longer,increasing the potential for these irregularities to migrate farther eastward.Second,we demonstrate that combined ROTI maps from Ina-CORS and GNSS receivers in East Asia and Australia can be used to monitor the development of ionospheric irregularities in Southeast and East Asia.We have demonstrated the combined ROTI maps to capture the development of ionospheric irregularities in the Southeast/East Asian sector during the G5 Geomagnetic Storm on May 11,2024.We observed simultaneous ionospheric irregularities in Japan and Australia,respectively propagating northwestward and southwestward,before midnight,whereas Southeast Asia’s equatorial and low-latitude regions exhibited irregularities post-midnight.By sharing ROTI maps from Indonesia and integrating them with regional GNSS networks,researchers can conduct comprehensive EPB studies,enhancing the understanding of EPB behavior across Southeast and East Asia and contributing significantly to ionospheric research.
基金Supported by Post-Subsidy Funds from the National Clinical Research Center,Ministry of Science and Technology of China,No.303-01-001-0272-08Beijing Municipal Administration of Hospitals Incubating Program,No.PX2022032Beijing Municipal Public Welfare Development and Reform Pilot Project for Medical Research Institutes(PWD&RPP-MRI),No.JYY2023-13.
文摘Diabetes is highly prevalent among the elderly worldwide,with the highest number of diabetes cases in China.Yet,the management of diabetes remains unsatisfactory.Recent advances in digital health technologies have facilitated the establishment of smart wards for diabetes patients.There is a lack of smart wards tailored specifically for older diabetes patients who encounter unique challenges in glycemic control and diabetes management,including an increased vulnerability to hypoglycemia,the presence of multiple chronic diseases,and cognitive decline.In this review,studies on digital health technologies for diabetes in China and beyond were summarized to elucidate how the adoption of digital health technologies,such as real-time continuous glucose monitoring,sensor-augmented pump technology,and their integration with 5th generation networks,big data cloud storage,and hospital information systems,can address issues specifically related to elderly diabetes patients in hospital wards.Furthermore,the challenges and future directions for establishing and implementing smart wards for elderly diabetes patients are discussed,and these challenges may also be applicable to other countries worldwide,not just in China.Taken together,the smart wards may enhance clinical outcomes,address specific issues,and eventually improve patient-centered hospital care for elderly patients with diabetes.
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 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 National Natural Science Foundation of China(Nos.12222513,12105345,12175292,and No.12405178)。
文摘Radio frequency(RF)cavities for advanced storage rings,also known as diffraction-limited storage rings,are under development.To this end,a competitive and promising approach involves normal-conducting continuous wave technology.The design and preliminary test of a 499.654 MHz RF cavity for the Wuhan Advanced Light Source(WALS)based on specific beam parameters were conducted at the SSRF.Multi-objective evolutionary algorithms have been utilized to optimize RF properties,such as the power loss and power density,resulting in better performance in the continuous wave mode.Further improvements were made to suppress multipacting effects in the working area.To operate stably with the beam,higher-order mode dampers were applied to better address the coupling bunch instability than in previous designs,along with thermal analysis to achieve the desired RF performance.Comprehensive simulation studies demonstrated the stable operation of the RF cavity at the defined beam parameters in the WALS design.A prototype RF cavity was then developed,and the RF performance results in a low-power test showed good agreement with the design and simulation,exhibiting readiness for high-power experiments and operation.
基金National Social Science Fund of China(No.2023-SKJJ-B-069).
文摘In GNSS denied environments,pseudolites have to rely on prior information,such as ground anchoring points,terrain matching or other multi-source means for positioning.This paper proposes a method of dynamic networking of UAVs pseudolites for accurate navigation with only inertial navigation during GNSS denied area,which can provide accurate positioning services without prior information like anchor points.On this basis,this paper proposes a mathematical model of UAV pseudolite networking to describe the relationship of UAV flight altitude,network service coverage and anti-jamming capabilities.This model demonstrates excellent anti-interference ability,which can achieve a maximum power enhancement of up to 54.58 dB.And it can also offer another operating mode with a maximum coverage range of up to 2675.47 km^(2),while still ensuring a power enhancement of 37.57dB.This method can effectively solve the problem of providing continuous positioning services as an alternative GNSS,and is also a powerful support solution for resilient Positioning,Navigation,and Timing(PNT)^([1]).
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.
