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
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
Plant diseases are a major threat that can severely impact the production of agriculture and forestry.This can lead to the disruption of ecosystem functions and health.With its ability to capture continuous narrow-ban...Plant diseases are a major threat that can severely impact the production of agriculture and forestry.This can lead to the disruption of ecosystem functions and health.With its ability to capture continuous narrow-band spectra,hyperspectral technology has become a crucial tool to monitor crop diseases using remote sensing.However,existing continuous wavelet analysis(CWA)methods suffer from feature redundancy issues,while the continuous wavelet projection algorithm(CWPA),an optimization approach for feature selection,has not been fully validated to monitor plant diseases.This study utilized rice bacterial leaf blight(BLB)as an example by evaluating the performance of four wavelet basis functions-Gaussian2,Mexican hat,Meyer,andMorlet-within theCWAandCWPAframeworks.Additionally,the classification models were constructed using the k-nearest neighbors(KNN),randomforest(RF),and Naïve Bayes(NB)algorithms.The results showed the following:(1)Compared to traditional CWA,CWPA significantly reduced the number of required features.Under the CWPA framework,almost all the model combinations achieved maximum classification accuracy with only one feature.In contrast,the CWA framework required three to seven features.(2)Thechoice of wavelet basis functions markedly affected the performance of themodel.Of the four functions tested,the Meyer wavelet demonstrated the best overall performance in both the CWPA and CWA frameworks.(3)Under theCWPAframework,theMeyer-KNNandMeyer-NBcombinations achieved the highest overall accuracy of 93.75%using just one feature.In contrast,under the CWA framework,the CWA-RF combination achieved comparable accuracy(93.75%)but required six features.This study verified the technical advantages of CWPA for monitoring crop diseases,identified an optimal wavelet basis function selection scheme,and provided reliable technical support to precisely monitor BLB in rice(Oryza sativa).Moreover,the proposed methodological framework offers a scalable approach for the early diagnosis and assessment of plant stress,which can contribute to improved accuracy and timeliness when plant stress is monitored.展开更多
Pediatric type 1 diabetes(T1D)is a lifelong condition requiring meticulous glucose management to prevent acute and chronic complications.Conventional management of diabetic patients does not allow for continuous monit...Pediatric type 1 diabetes(T1D)is a lifelong condition requiring meticulous glucose management to prevent acute and chronic complications.Conventional management of diabetic patients does not allow for continuous monitoring of glucose trends,and can place patients at risk for hypo-and hyperglycemia.Continuous glucose monitors(CGMs)have emerged as a mainstay for pediatric diabetic care and are continuing to advance treatment by providing real-time blood glucose(BG)data,with trend analysis aided by machine learning(ML)algorithms.These predictive analytics serve to prevent against dangerous BG variations in the perioperative environment for fasted children undergoing surgical stress.Integration of CGM data into electronic health records(EHR)is essential,as it establishes a foundation for future technologic interfaces with artificial intelligence(AI).Challenges in perioperative CGM implementation include equitable device access,protection of patient privacy and data accuracy,ensuring institution of standardized protocols,and financing the cumbersome healthcare costs associated with staff training and technology platforms.This paper advocates for implementation of CGM data into the EHR utilizing multiple facets of AI/ML algorithms.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 insensitive munitions compound nitroguanidine(NQ)is used by the U.S.Army to avoid unintended explosions.However,NQ also represents an emerging contaminant whose environmental emissions can cause toxicity toward aq...The insensitive munitions compound nitroguanidine(NQ)is used by the U.S.Army to avoid unintended explosions.However,NQ also represents an emerging contaminant whose environmental emissions can cause toxicity toward aquatic organisms,indicating the need for effective remediation strategies.Thus,we investigated the feasibility of treating water contaminated with NQ in continuous-flow columns packed with zero-valent iron(ZVI)or iron sulfide(FeS).Initially,the impact of pH on NQ transformation by ZVI or FeS was evaluated in batch experiments.The pseudo first-order rate constant for NQ transformation(k_(1,NQ))by ZVI was 8-10 times higher at pH 3.0 compared to pH 5.5 and 7.0,whereas similar k_(1,NQ)values were obtained for FeS at pH 5.5-10.0.Based on these findings,the influent p H fed to the ZVIand Fe S-packed columns was adjusted to 3.0 and 5.5,respectively.Both reactors transformed NQ into nitrosoguanidine(Nso Q).Further transformation of Nso Q by ZVI produced aminoguanidine,guanidine,and cyanamide,whereas Nso Q transformation by Fe S produced guanidine,ammonium,and traces of urea.ZVI outperformed Fe S as a reactive material to remove NQ.The ZVI-packed column effectively removed NQ below detection even after 45 d of operation(490 pore volumes,PV).In contrast,NQ breakthrough(removal efficiency<85%)was observed after 18 d(180 PV)in the Fe S-packed column.The high NQ removal efficiency and long service life of the ZVI-packed column(>490 PV)suggest that the technology is a promising approach for NQ treatment in packed-bed reactors and in situ remediation.展开更多
This paper investigates the economic and operational trade-offs between continuous manufacturing and batch processing in the context of biopharmaceutical engineering design,through the lens of project management.The s...This paper investigates the economic and operational trade-offs between continuous manufacturing and batch processing in the context of biopharmaceutical engineering design,through the lens of project management.The study explores the fundamental principles of both manufacturing modes,assesses their implications on capital and operational expenditures,and evaluates their performance against key project management metrics such as cost,time,quality,and risk.Drawing on current regulatory guidance,industrial practices,and technological advances,the paper concludes that while continuous manufacturing offers significant benefits in process efficiency and quality control,its implementation requires substantial upfront investment,risk management,and stakeholder alignment.The study aims to support informed decision-making in early-stage biopharmaceutical facility and process design.展开更多
We present a compact optical delay line(ODL)with wide-range continuous tunability on thin-film lithium niobate platform.The proposed device integrates an unbalanced Mach-Zehnder interferometer(MZI)architecture with du...We present a compact optical delay line(ODL)with wide-range continuous tunability on thin-film lithium niobate platform.The proposed device integrates an unbalanced Mach-Zehnder interferometer(MZI)architecture with dual tunable couplers,where each coupler comprises two 2×2 multimode interferometers and a MZI phase-tuning section.Experimental results demonstrate continuous delay tuning from 0 to 293 ps through synchronized control of coupling coefficients,corresponding to a 4 cm path difference between interferometer arms.The measured delay range exhibits excellent agreement with theoretical predictions derived from ODL waveguide parameters.This result addresses critical challenges in integrated photonic systems that require precise temporal control,particularly for applications in optical communications and quantum information processing,where a wide tuning range is paramount.展开更多
Background:Long-term exposure to light has emerged as a novel risk factor for metabolic diseases.The whitening of brown adipose tissue(BAT)may play an important role in metabolic disorders caused by long-term continuo...Background:Long-term exposure to light has emerged as a novel risk factor for metabolic diseases.The whitening of brown adipose tissue(BAT)may play an important role in metabolic disorders caused by long-term continuous light exposure.This study aimed to investigate the morphological and functional alterations in BAT under continuous light conditions and to identify traditional Chinese medicine compounds capable of reversing these changes.Methods:A metabolic disorder model was established by subjecting mice to continuous light exposure for 5 weeks.During this period,body weight,food intake,and body fat percentage were monitored.Serum levels of triglyceride(TG),total cholesterol(TC),high density lipoprotein cholesterol(HDL-C),and low density lipoprotein cholesterol(LDL-C)were measured to assess lipid metabolism.Histological changes in BAT were examined using H&E staining.The expression of the thermogenic marker uncoupling protein 1(UCP1)in BAT was determined by RT-qPCR and Western blot to evaluate thermogenic function.RNA sequencing(RNA-seq)was employed to identify differentially expressed genes(DEGs)involved in BAT whitening induced by prolonged continuous light exposure.DEGs were analyzed using the connectivity map(CMap)database to identify potential preventive and therapeutic compounds.The therapeutic efficacy of the selected compounds was subsequently evaluated using the above indicators,and key pathways were validated through western blot analysis.Results:After 5 weeks of continuous light exposure,mice exhibited increased body fat percentage and serum levels of TG,impaired mitochondrial function,reduced thermogenic capacity,and whitening of BAT.Gene ontology(GO)and Kyoto encyclopedia of genes and genomes(KEGG)enrichment analyses indicated that BAT whitening was primarily associated with the adenosine 5'-monophosphate-activated protein kinase(AMPK)signaling pathway,fatty acid metabolism,and circadian rhythm.Ten hub genes identified using Cytoscape were mainly related to AMPK signaling and heat shock proteins.In vivo experiments showed that cordycepin significantly attenuated the increase in body fat percentage caused by prolonged light exposure.This effect was mediated by activation of the AMPK/PGC-1α/UCP1 signaling pathway,which restored the multilocular morphology and thermogenic function of BAT.Conclusion:Cordycepin mitigates continuous light-induced BAT whitening and metabolic disturbances by activating the AMPK signaling pathway.展开更多
Benefiting from the widespread potential applications in the era of the Internet of Thing and metaverse,triboelectric and piezoelectric nanogenerators(TENG&PENG)have attracted considerably increasing attention.The...Benefiting from the widespread potential applications in the era of the Internet of Thing and metaverse,triboelectric and piezoelectric nanogenerators(TENG&PENG)have attracted considerably increasing attention.Their outstanding characteristics,such as self-powered ability,high output performance,integration compatibility,cost-effectiveness,simple configurations,and versatile operation modes,could effectively expand the lifetime of vastly distributed wearable,implantable,and environmental devices,eventually achieving self-sustainable,maintenance-free,and reliable systems.However,current triboelectric/piezoelectric based active(i.e.self-powered)sensors still encounter serious bottlenecks in continuous monitoring and multimodal applications due to their intrinsic limitations of monomodal kinetic response and discontinuous transient output.This work systematically summarizes and evaluates the recent research endeavors to address the above challenges,with detailed discussions on the challenge origins,designing strategies,device performance,and corresponding diverse applications.Finally,conclusions and outlook regarding the research gap in self-powered continuous multimodal monitoring systems are provided,proposing the necessity of future research development in this field.展开更多
Continuous cropping can lead to soil environment deterioration,cause plant health problems,and reduce crop productivity.However,the response mechanisms of soil microbial co-occurrence patterns to the duration of conti...Continuous cropping can lead to soil environment deterioration,cause plant health problems,and reduce crop productivity.However,the response mechanisms of soil microbial co-occurrence patterns to the duration of continuous melon cropping remain poorly understood.Here,we employed the metagenomic techniques to comparatively investigate the bulk and rhizosphere soil microbial communities of major melon-producing regions(where the duration of continuous melon cropping ranges from 1 to 30 a)in the eastern and southern parts of Xinjiang Uygur Autonomous Region,China.The results showed that soil pH clearly decreased with increasing melon cropping duration,while soil electrical conductivity(EC)and the other soil nutrient indices increased with increasing melon cropping duration(with the exception of AN and TK in the southern melon-producing region).The most dominant bacterial phyla were Proteobacteria and Actinobacteria,and the most abundant fungal phyla were Ascomycota and Mucoromycota.Redundancy analysis(RDA)indicated that soil pH and EC had no significant effects on the bacterial communities.However,after many years of continuous melon cropping in the southern melon-producing region,fungal communities were significantly negatively correlated with soil pH and significantly positively correlated with soil EC(P<0.050).Co-occurrence network analysis showed that continuous melon cropping increased the complexity but decreased the connectivity of the cross-domain microbial networks.Moreover,the enrichment patterns of microorganisms in the main microbial network modules varied significantly with the duration of continuous melon cropping.Based on the analysis of keystone taxa,we found that continuous melon cropping increased some plant pathogens(e.g.,Fusarium and Stagonospora)but decreased beneficial bacteria(e.g.,Mesorhizobium and Pseudoxanthomonas).In conclusion,this study has greatly enhanced the understanding of the effects of continuous melon cropping on alterations in the microbial community structure and ecological networks in Xinjiang.展开更多
The crankshaft is subjected to complex rotational centrifugal force,periodic gas inertia force,and reciprocating inertia force during its working process.Consequently,the homogeneity requirement for crankshaft steel i...The crankshaft is subjected to complex rotational centrifugal force,periodic gas inertia force,and reciprocating inertia force during its working process.Consequently,the homogeneity requirement for crankshaft steel is exceptionally high.The distribution characteristics of center segregation and spot segregation of continuous casting bloom 42CrMoA crankshaft steel were analyzed by experiments,and the control mechanism of spot segregation by soft reduction zone and reduction amount was discussed.When the center solid fraction is between 0.61 and 1.00,an 8-mm soft reduction has a negligible impact on the flow of liquid steel at the end of solidification.Although it effectively improves center segregation,the improvement of spot segregation is limited.On the other hand,when the center solid fraction is between 0.31 and 1.00,a reduction of 10–12 mm,along with an expanded reduction zone and increased reduction amount,significantly promotes the flow of liquid steel at the end of solidification,reduces the size of equiaxed grains,mitigates the center negative segregation,and decreases the maximum size of spot segregation from 2954.29 to 1354.07μm.The number of spot segregations and the solutes enrichment degree of C,Cr,and Mn have also been significantly improved.An appropriate soft reduction zone and reduction amount can markedly ameliorate the semi-macro spot segregation of crankshaft steel blooms,thereby providing high-quality raw materials for subsequent products and enhancing the competitiveness of crankshaft products.展开更多
Objective:To evaluate the effectiveness of continuous nursing interventions in elderly patients with COPD in the stable phase and frailty.Methods:Sixty elderly patients with COPD in the stable phase and frailty,treate...Objective:To evaluate the effectiveness of continuous nursing interventions in elderly patients with COPD in the stable phase and frailty.Methods:Sixty elderly patients with COPD in the stable phase and frailty,treated between January 2024 and August 2024,were selected as the study subjects.Patients were randomly divided into two groups(30 each)using a drawing method.Patients who drew a black token were assigned to the intervention group and received continuous nursing interventions,while those who drew a red token were assigned to the nursing group and received standard nursing care.The quality of care between the groups was compared.Results:Pulmonary function indicators in the intervention group were significantly better than those in the nursing group(P<0.05).Immune function in the intervention group was also significantly higher than in the nursing group(P<0.05).Before the intervention,there was no significant difference in self-care ability between the two groups(P>0.05).However,post-intervention,both groups showed improved self-care abilities,with the intervention group scoring significantly higher than the nursing group(P<0.05).Similarly,before the intervention,there was no significant difference in quality-of-life scores(P>0.05),but post-intervention,both groups exhibited increased scores,with the intervention group outperforming the nursing group significantly(P<0.05).Conclusion:Continuous nursing interventions significantly improve outcomes in elderly patients with COPD in the stable phase and frailty,warranting broader implementation.展开更多
Precipitation of carbides, nitrides, and carbonitrides is an important factor influencing the formation of surface transverse cracks in the continuous casting of microalloyed steel, affecting the quality and yield of ...Precipitation of carbides, nitrides, and carbonitrides is an important factor influencing the formation of surface transverse cracks in the continuous casting of microalloyed steel, affecting the quality and yield of the final product. Based on previous investigation, the precipitation sequence and temperature, position and mode, as well as the size, morphology, and number of different types of precipitates were reviewed. The effects of C, N, Nb, Ti, and V on the precipitation behavior and surface transverse cracks in continuous casting slabs were summarized, with a particular emphasis on the new achievements concerning Ti addition. The critical amounts of different elements to avoid serious surface cracks during continuous casting were proposed. The control mechanisms and industrial effects of composition optimization, cooling design, and chamfered mold configuration to improve surface transverse cracks in continuous casting slabs were also illustrated, and the recent application of surface microstructure control technology was emphasized. The characteristics, advantages, and shortcomings of existing theoretical and experimental methods in investigating continuous casting surface cracks regarding precipitation are finally discussed, and a new setup with advanced functions is introduced.展开更多
Salt deposits in China predominantly originate from lake deposits,characterized by thin salt beds interspersed with numerous interlayers,collectively termed bedded salt formations.Historically,the solution mining prac...Salt deposits in China predominantly originate from lake deposits,characterized by thin salt beds interspersed with numerous interlayers,collectively termed bedded salt formations.Historically,the solution mining practices have adopted the layered solution mining approach,inspired by coal mining techniques.However,this approach fails to account for the unique challenges of salt solution mining.Practical implementation is inefficient,costs escalate post-construction,and cavern geometry is constrained by salt beds thickness.Additionally,resource loss in abandoned beds and stability risks in adjacent mining zones remain unresolved.This study investigates mining scheme selection for low-grade salt deposits in Huai'an Salt Basin,introducing a continuous solution mining method that traverses multiple interlayers.Through comprehensive analysis of plastic deformation in caverns and surrounding rock,volume shrinkage rates,and economic costs comparing continuous and layered solution mining approaches,the results demonstrate that:(1)In the layered solution mining with horizontal interconnected wells scheme,plastic deformation zones propagate unevenly,posing interlayer connectivity risks.Concurrently,roof subsidence and floor heave destabilize the structure;(2)the continuous solution mining with horizontal interconnected wells scheme reduces plastic deformation zones to 3.4%of cavern volume,with volumetric shrinkage below 17%,markedly improving stability;(3)Economically,the continuous solution mining scheme generates caverns 2.43 times larger than the layered solution mining,slashing unit volume costs to 41.1%while enhancing resource recovery and long-term viability.The continuous method demonstrates distinct economic advantages and achieves higher resource utilization efficiency in solution mining compared to layered mining.Furthermore,its superior cavern stability presents strong potential for large-scale implementation.展开更多
Dear Editor,The distributed constraint optimization problems(DCOPs) [1]-[3]provide an efficient model for solving the cooperative problems of multi-agent systems, which has been successfully applied to model the real-...Dear Editor,The distributed constraint optimization problems(DCOPs) [1]-[3]provide an efficient model for solving the cooperative problems of multi-agent systems, which has been successfully applied to model the real-world problems like the distributed scheduling [4], sensor network management [5], [6], multi-robot coordination [7], and smart grid [8]. However, DCOPs were not well suited to solve the problems with continuous variables and constraint cost in functional form, such as the target tracking sensor orientation [9], the air and ground cooperative surveillance [10], and the sensor network coverage [11].展开更多
A mathematical model coupling flow,solidification,strain-stress,and interface failure was developed.Following identification of crack source type through thermal tensile experiment and validation by strain-stress comp...A mathematical model coupling flow,solidification,strain-stress,and interface failure was developed.Following identification of crack source type through thermal tensile experiment and validation by strain-stress comparison,the model was used to investigate slab cracking tendency near precipitated phases,considering various locations,sizes and shapes of them.The results show that the jet from submerged entry nozzle creates a“double roll”flow pattern during continuous casting,resulting in more uniform temperature distributions at slab corner and wide surface center compared with narrow surface center.Consequently,precipitated phases,particularly those located on the narrow surface,readily induce stress concentration and thus increase cracking tendency.A smaller precipitated phase size can reduce the stress concentration zone,while a more spherical shape can distribute surrounding stress along its surface and lower the internal stress within it,thereby decreasing the risk of slab cracking during continuous casting.The optimal precipitated phase exhibits a spherical or ellipsoidal shape with a major axis of less than 5µm,minimizing its potential to initiate cracks.展开更多
The electromagnetic swirling flow in nozzle(EMSFN)technique is designed to mitigate the adverse effects of unstable and uneven flow within the submerged entry nozzle in continuous casting.Utilizing electromagnetic for...The electromagnetic swirling flow in nozzle(EMSFN)technique is designed to mitigate the adverse effects of unstable and uneven flow within the submerged entry nozzle in continuous casting.Utilizing electromagnetic forces,EMSFN stabilizes the flow within the nozzle,leading to a more controlled flow in the mold.Numerical simulations were used to quantitatively analyze the magnetic and flow fields in a slab continuous casting system under EMSFN.Results indicate that EMSFN significantly stabilizes the outflow from the nozzle,with stability increasing with higher current intensity.At 10,000 Ampere-turns(At)of the coil,meniscus fluctuations were unstable.They stabilized at 13,000 At,with minimal changes observed beyond this point.The optimal current intensity for stable mold flow,at a casting speed of 1.56 m/min,is 13,000 At.These findings confirm the effectiveness of EMSFN in stabilizing the internal flow field of the slab mold and determining optimal operational current intensity.展开更多
Drive-by techniques for bridge health monitoring have drawn increasing attention from researchers and practitioners,in the attempt to make bridge condition-based monitoring more cost-efficient.In this work,the authors...Drive-by techniques for bridge health monitoring have drawn increasing attention from researchers and practitioners,in the attempt to make bridge condition-based monitoring more cost-efficient.In this work,the authors propose a drive-by approach that takes advantage from bogie vertical accelerations to assess bridge health status.To do so,continuous wavelet transform is combined with multiple sparse autoencoders that allow for damage detection and localization across bridge span.According to authors’best knowledge,this is the first case in which an unsupervised technique,which relies on the use of sparse autoencoders,is used to localize damages.The bridge considered in this work is a Warren steel truss bridge,whose finite element model is referred to an actual structure,belonging to the Italian railway line.To investigate damage detection and localization performances,different operational variables are accounted for:train weight,forward speed and track irregularity evolution in time.Two configurations for the virtual measuring channels were investigated:as a result,better performances were obtained by exploiting the vertical accelerations of both the bogies of the leading coach instead of using only one single acceleration signal.展开更多
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.
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‘Pioneer’and‘Leading Goose’R&D Program of Zhejiang(Grant No.2023C02018)Zhejiang Provincial Natural Science Foundation of China(Grant No.LTGN23D010002)+2 种基金National Natural Science Foundation of China(Grant No.42371385)Funds of the Natural Science Foundation of Hangzhou(Grant No.2024SZRYBD010001)Nanxun Scholars Program of ZJWEU(Grant No.RC2022010755).
文摘Plant diseases are a major threat that can severely impact the production of agriculture and forestry.This can lead to the disruption of ecosystem functions and health.With its ability to capture continuous narrow-band spectra,hyperspectral technology has become a crucial tool to monitor crop diseases using remote sensing.However,existing continuous wavelet analysis(CWA)methods suffer from feature redundancy issues,while the continuous wavelet projection algorithm(CWPA),an optimization approach for feature selection,has not been fully validated to monitor plant diseases.This study utilized rice bacterial leaf blight(BLB)as an example by evaluating the performance of four wavelet basis functions-Gaussian2,Mexican hat,Meyer,andMorlet-within theCWAandCWPAframeworks.Additionally,the classification models were constructed using the k-nearest neighbors(KNN),randomforest(RF),and Naïve Bayes(NB)algorithms.The results showed the following:(1)Compared to traditional CWA,CWPA significantly reduced the number of required features.Under the CWPA framework,almost all the model combinations achieved maximum classification accuracy with only one feature.In contrast,the CWA framework required three to seven features.(2)Thechoice of wavelet basis functions markedly affected the performance of themodel.Of the four functions tested,the Meyer wavelet demonstrated the best overall performance in both the CWPA and CWA frameworks.(3)Under theCWPAframework,theMeyer-KNNandMeyer-NBcombinations achieved the highest overall accuracy of 93.75%using just one feature.In contrast,under the CWA framework,the CWA-RF combination achieved comparable accuracy(93.75%)but required six features.This study verified the technical advantages of CWPA for monitoring crop diseases,identified an optimal wavelet basis function selection scheme,and provided reliable technical support to precisely monitor BLB in rice(Oryza sativa).Moreover,the proposed methodological framework offers a scalable approach for the early diagnosis and assessment of plant stress,which can contribute to improved accuracy and timeliness when plant stress is monitored.
文摘Pediatric type 1 diabetes(T1D)is a lifelong condition requiring meticulous glucose management to prevent acute and chronic complications.Conventional management of diabetic patients does not allow for continuous monitoring of glucose trends,and can place patients at risk for hypo-and hyperglycemia.Continuous glucose monitors(CGMs)have emerged as a mainstay for pediatric diabetic care and are continuing to advance treatment by providing real-time blood glucose(BG)data,with trend analysis aided by machine learning(ML)algorithms.These predictive analytics serve to prevent against dangerous BG variations in the perioperative environment for fasted children undergoing surgical stress.Integration of CGM data into electronic health records(EHR)is essential,as it establishes a foundation for future technologic interfaces with artificial intelligence(AI).Challenges in perioperative CGM implementation include equitable device access,protection of patient privacy and data accuracy,ensuring institution of standardized protocols,and financing the cumbersome healthcare costs associated with staff training and technology platforms.This paper advocates for implementation of CGM data into the EHR utilizing multiple facets of AI/ML algorithms.
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financially supported by the Strategic Environmental Research and Development Program(Grant No.ER19-1075)。
文摘The insensitive munitions compound nitroguanidine(NQ)is used by the U.S.Army to avoid unintended explosions.However,NQ also represents an emerging contaminant whose environmental emissions can cause toxicity toward aquatic organisms,indicating the need for effective remediation strategies.Thus,we investigated the feasibility of treating water contaminated with NQ in continuous-flow columns packed with zero-valent iron(ZVI)or iron sulfide(FeS).Initially,the impact of pH on NQ transformation by ZVI or FeS was evaluated in batch experiments.The pseudo first-order rate constant for NQ transformation(k_(1,NQ))by ZVI was 8-10 times higher at pH 3.0 compared to pH 5.5 and 7.0,whereas similar k_(1,NQ)values were obtained for FeS at pH 5.5-10.0.Based on these findings,the influent p H fed to the ZVIand Fe S-packed columns was adjusted to 3.0 and 5.5,respectively.Both reactors transformed NQ into nitrosoguanidine(Nso Q).Further transformation of Nso Q by ZVI produced aminoguanidine,guanidine,and cyanamide,whereas Nso Q transformation by Fe S produced guanidine,ammonium,and traces of urea.ZVI outperformed Fe S as a reactive material to remove NQ.The ZVI-packed column effectively removed NQ below detection even after 45 d of operation(490 pore volumes,PV).In contrast,NQ breakthrough(removal efficiency<85%)was observed after 18 d(180 PV)in the Fe S-packed column.The high NQ removal efficiency and long service life of the ZVI-packed column(>490 PV)suggest that the technology is a promising approach for NQ treatment in packed-bed reactors and in situ remediation.
文摘This paper investigates the economic and operational trade-offs between continuous manufacturing and batch processing in the context of biopharmaceutical engineering design,through the lens of project management.The study explores the fundamental principles of both manufacturing modes,assesses their implications on capital and operational expenditures,and evaluates their performance against key project management metrics such as cost,time,quality,and risk.Drawing on current regulatory guidance,industrial practices,and technological advances,the paper concludes that while continuous manufacturing offers significant benefits in process efficiency and quality control,its implementation requires substantial upfront investment,risk management,and stakeholder alignment.The study aims to support informed decision-making in early-stage biopharmaceutical facility and process design.
基金supported by the National Natural Science Foundation of China(Grant Nos.12192251,12334014,12404378,92480001,12134001,12174113,12174107,12474325,12404379,and 12474378)the Innovation Program for Quantum Science and Technology(Grant No.2021ZD0301403)+1 种基金Shanghai Municipal Science and Technology Major Project(Grant No.2019SHZDZX01)Fundamental Research Funds for the Central Universities,the Engineering Research Center for Nanophotonics&Advanced Instrument,Ministry of Education,East China Normal University(Grant No.2023nmc005).
文摘We present a compact optical delay line(ODL)with wide-range continuous tunability on thin-film lithium niobate platform.The proposed device integrates an unbalanced Mach-Zehnder interferometer(MZI)architecture with dual tunable couplers,where each coupler comprises two 2×2 multimode interferometers and a MZI phase-tuning section.Experimental results demonstrate continuous delay tuning from 0 to 293 ps through synchronized control of coupling coefficients,corresponding to a 4 cm path difference between interferometer arms.The measured delay range exhibits excellent agreement with theoretical predictions derived from ODL waveguide parameters.This result addresses critical challenges in integrated photonic systems that require precise temporal control,particularly for applications in optical communications and quantum information processing,where a wide tuning range is paramount.
文摘Background:Long-term exposure to light has emerged as a novel risk factor for metabolic diseases.The whitening of brown adipose tissue(BAT)may play an important role in metabolic disorders caused by long-term continuous light exposure.This study aimed to investigate the morphological and functional alterations in BAT under continuous light conditions and to identify traditional Chinese medicine compounds capable of reversing these changes.Methods:A metabolic disorder model was established by subjecting mice to continuous light exposure for 5 weeks.During this period,body weight,food intake,and body fat percentage were monitored.Serum levels of triglyceride(TG),total cholesterol(TC),high density lipoprotein cholesterol(HDL-C),and low density lipoprotein cholesterol(LDL-C)were measured to assess lipid metabolism.Histological changes in BAT were examined using H&E staining.The expression of the thermogenic marker uncoupling protein 1(UCP1)in BAT was determined by RT-qPCR and Western blot to evaluate thermogenic function.RNA sequencing(RNA-seq)was employed to identify differentially expressed genes(DEGs)involved in BAT whitening induced by prolonged continuous light exposure.DEGs were analyzed using the connectivity map(CMap)database to identify potential preventive and therapeutic compounds.The therapeutic efficacy of the selected compounds was subsequently evaluated using the above indicators,and key pathways were validated through western blot analysis.Results:After 5 weeks of continuous light exposure,mice exhibited increased body fat percentage and serum levels of TG,impaired mitochondrial function,reduced thermogenic capacity,and whitening of BAT.Gene ontology(GO)and Kyoto encyclopedia of genes and genomes(KEGG)enrichment analyses indicated that BAT whitening was primarily associated with the adenosine 5'-monophosphate-activated protein kinase(AMPK)signaling pathway,fatty acid metabolism,and circadian rhythm.Ten hub genes identified using Cytoscape were mainly related to AMPK signaling and heat shock proteins.In vivo experiments showed that cordycepin significantly attenuated the increase in body fat percentage caused by prolonged light exposure.This effect was mediated by activation of the AMPK/PGC-1α/UCP1 signaling pathway,which restored the multilocular morphology and thermogenic function of BAT.Conclusion:Cordycepin mitigates continuous light-induced BAT whitening and metabolic disturbances by activating the AMPK signaling pathway.
基金supported by the National Key R&D Program of China(Grant Nos.2022YFB3603403,2021YFB3600502)the National Natural Science Foundation of China(Grant Nos.62075040,62301150)+3 种基金the Southeast University Interdisciplinary Research Program for Young Scholars(2024FGC1007)the Start-up Research Fund of Southeast University(RF1028623164)the Nanjing Science and Technology Innovation Project for Returned Overseas Talent(4206002302)the Fundamental Research Funds for the Central Universities(2242024K40015).
文摘Benefiting from the widespread potential applications in the era of the Internet of Thing and metaverse,triboelectric and piezoelectric nanogenerators(TENG&PENG)have attracted considerably increasing attention.Their outstanding characteristics,such as self-powered ability,high output performance,integration compatibility,cost-effectiveness,simple configurations,and versatile operation modes,could effectively expand the lifetime of vastly distributed wearable,implantable,and environmental devices,eventually achieving self-sustainable,maintenance-free,and reliable systems.However,current triboelectric/piezoelectric based active(i.e.self-powered)sensors still encounter serious bottlenecks in continuous monitoring and multimodal applications due to their intrinsic limitations of monomodal kinetic response and discontinuous transient output.This work systematically summarizes and evaluates the recent research endeavors to address the above challenges,with detailed discussions on the challenge origins,designing strategies,device performance,and corresponding diverse applications.Finally,conclusions and outlook regarding the research gap in self-powered continuous multimodal monitoring systems are provided,proposing the necessity of future research development in this field.
基金funded by the Major Science and Technology Projects of Xinjiang Uygur Autonomous Region(2022A02007-4)the Xinjiang Uygur Autonomous Region Natural Science Foundation Youth Project(2024D01B31)the Graduate Student Research Innovation Project of Xinjiang Agricultural University(XJAUGRI2024033).
文摘Continuous cropping can lead to soil environment deterioration,cause plant health problems,and reduce crop productivity.However,the response mechanisms of soil microbial co-occurrence patterns to the duration of continuous melon cropping remain poorly understood.Here,we employed the metagenomic techniques to comparatively investigate the bulk and rhizosphere soil microbial communities of major melon-producing regions(where the duration of continuous melon cropping ranges from 1 to 30 a)in the eastern and southern parts of Xinjiang Uygur Autonomous Region,China.The results showed that soil pH clearly decreased with increasing melon cropping duration,while soil electrical conductivity(EC)and the other soil nutrient indices increased with increasing melon cropping duration(with the exception of AN and TK in the southern melon-producing region).The most dominant bacterial phyla were Proteobacteria and Actinobacteria,and the most abundant fungal phyla were Ascomycota and Mucoromycota.Redundancy analysis(RDA)indicated that soil pH and EC had no significant effects on the bacterial communities.However,after many years of continuous melon cropping in the southern melon-producing region,fungal communities were significantly negatively correlated with soil pH and significantly positively correlated with soil EC(P<0.050).Co-occurrence network analysis showed that continuous melon cropping increased the complexity but decreased the connectivity of the cross-domain microbial networks.Moreover,the enrichment patterns of microorganisms in the main microbial network modules varied significantly with the duration of continuous melon cropping.Based on the analysis of keystone taxa,we found that continuous melon cropping increased some plant pathogens(e.g.,Fusarium and Stagonospora)but decreased beneficial bacteria(e.g.,Mesorhizobium and Pseudoxanthomonas).In conclusion,this study has greatly enhanced the understanding of the effects of continuous melon cropping on alterations in the microbial community structure and ecological networks in Xinjiang.
基金funded by the National Natural Science Foundation of China(NSFC)(Grant No.U1860111)Weifang Science and Technology Development Plan Project(Project No.2023ZJ1166).
文摘The crankshaft is subjected to complex rotational centrifugal force,periodic gas inertia force,and reciprocating inertia force during its working process.Consequently,the homogeneity requirement for crankshaft steel is exceptionally high.The distribution characteristics of center segregation and spot segregation of continuous casting bloom 42CrMoA crankshaft steel were analyzed by experiments,and the control mechanism of spot segregation by soft reduction zone and reduction amount was discussed.When the center solid fraction is between 0.61 and 1.00,an 8-mm soft reduction has a negligible impact on the flow of liquid steel at the end of solidification.Although it effectively improves center segregation,the improvement of spot segregation is limited.On the other hand,when the center solid fraction is between 0.31 and 1.00,a reduction of 10–12 mm,along with an expanded reduction zone and increased reduction amount,significantly promotes the flow of liquid steel at the end of solidification,reduces the size of equiaxed grains,mitigates the center negative segregation,and decreases the maximum size of spot segregation from 2954.29 to 1354.07μm.The number of spot segregations and the solutes enrichment degree of C,Cr,and Mn have also been significantly improved.An appropriate soft reduction zone and reduction amount can markedly ameliorate the semi-macro spot segregation of crankshaft steel blooms,thereby providing high-quality raw materials for subsequent products and enhancing the competitiveness of crankshaft products.
文摘Objective:To evaluate the effectiveness of continuous nursing interventions in elderly patients with COPD in the stable phase and frailty.Methods:Sixty elderly patients with COPD in the stable phase and frailty,treated between January 2024 and August 2024,were selected as the study subjects.Patients were randomly divided into two groups(30 each)using a drawing method.Patients who drew a black token were assigned to the intervention group and received continuous nursing interventions,while those who drew a red token were assigned to the nursing group and received standard nursing care.The quality of care between the groups was compared.Results:Pulmonary function indicators in the intervention group were significantly better than those in the nursing group(P<0.05).Immune function in the intervention group was also significantly higher than in the nursing group(P<0.05).Before the intervention,there was no significant difference in self-care ability between the two groups(P>0.05).However,post-intervention,both groups showed improved self-care abilities,with the intervention group scoring significantly higher than the nursing group(P<0.05).Similarly,before the intervention,there was no significant difference in quality-of-life scores(P>0.05),but post-intervention,both groups exhibited increased scores,with the intervention group outperforming the nursing group significantly(P<0.05).Conclusion:Continuous nursing interventions significantly improve outcomes in elderly patients with COPD in the stable phase and frailty,warranting broader implementation.
基金supported by the Fundamental Research Funds for the Central Universities(No.FRF-TP-19-017A3)National Natural Science Foundation of China(No.51874026).
文摘Precipitation of carbides, nitrides, and carbonitrides is an important factor influencing the formation of surface transverse cracks in the continuous casting of microalloyed steel, affecting the quality and yield of the final product. Based on previous investigation, the precipitation sequence and temperature, position and mode, as well as the size, morphology, and number of different types of precipitates were reviewed. The effects of C, N, Nb, Ti, and V on the precipitation behavior and surface transverse cracks in continuous casting slabs were summarized, with a particular emphasis on the new achievements concerning Ti addition. The critical amounts of different elements to avoid serious surface cracks during continuous casting were proposed. The control mechanisms and industrial effects of composition optimization, cooling design, and chamfered mold configuration to improve surface transverse cracks in continuous casting slabs were also illustrated, and the recent application of surface microstructure control technology was emphasized. The characteristics, advantages, and shortcomings of existing theoretical and experimental methods in investigating continuous casting surface cracks regarding precipitation are finally discussed, and a new setup with advanced functions is introduced.
基金supported by the National Natural Science Foundation of China(Nos.42177124 and 41877277)Open Research Fund of State Key Laboratory of Geomechanics and Geotechnical Engineering,Institute of Rock and Soil Mechanics,Chinese Academy of Sciences(No.SKLGME022011)+2 种基金Fundamental Research Funds for the Central Universities(No.2024KYJD1011)Frontier Technologies R&D Program of Jiangsu(No.BF2024056)the Graduate Innovation Program of China University of Mining and Technology(No.KYCX25_3085)。
文摘Salt deposits in China predominantly originate from lake deposits,characterized by thin salt beds interspersed with numerous interlayers,collectively termed bedded salt formations.Historically,the solution mining practices have adopted the layered solution mining approach,inspired by coal mining techniques.However,this approach fails to account for the unique challenges of salt solution mining.Practical implementation is inefficient,costs escalate post-construction,and cavern geometry is constrained by salt beds thickness.Additionally,resource loss in abandoned beds and stability risks in adjacent mining zones remain unresolved.This study investigates mining scheme selection for low-grade salt deposits in Huai'an Salt Basin,introducing a continuous solution mining method that traverses multiple interlayers.Through comprehensive analysis of plastic deformation in caverns and surrounding rock,volume shrinkage rates,and economic costs comparing continuous and layered solution mining approaches,the results demonstrate that:(1)In the layered solution mining with horizontal interconnected wells scheme,plastic deformation zones propagate unevenly,posing interlayer connectivity risks.Concurrently,roof subsidence and floor heave destabilize the structure;(2)the continuous solution mining with horizontal interconnected wells scheme reduces plastic deformation zones to 3.4%of cavern volume,with volumetric shrinkage below 17%,markedly improving stability;(3)Economically,the continuous solution mining scheme generates caverns 2.43 times larger than the layered solution mining,slashing unit volume costs to 41.1%while enhancing resource recovery and long-term viability.The continuous method demonstrates distinct economic advantages and achieves higher resource utilization efficiency in solution mining compared to layered mining.Furthermore,its superior cavern stability presents strong potential for large-scale implementation.
基金supported by the National Nature Science Foundation of China(62272078)
文摘Dear Editor,The distributed constraint optimization problems(DCOPs) [1]-[3]provide an efficient model for solving the cooperative problems of multi-agent systems, which has been successfully applied to model the real-world problems like the distributed scheduling [4], sensor network management [5], [6], multi-robot coordination [7], and smart grid [8]. However, DCOPs were not well suited to solve the problems with continuous variables and constraint cost in functional form, such as the target tracking sensor orientation [9], the air and ground cooperative surveillance [10], and the sensor network coverage [11].
基金supported by National Natural Science Foundation of China(Nos.52325406 and 52374330)Fundamental Research Funds for the Central Universities(No.N2225046).
文摘A mathematical model coupling flow,solidification,strain-stress,and interface failure was developed.Following identification of crack source type through thermal tensile experiment and validation by strain-stress comparison,the model was used to investigate slab cracking tendency near precipitated phases,considering various locations,sizes and shapes of them.The results show that the jet from submerged entry nozzle creates a“double roll”flow pattern during continuous casting,resulting in more uniform temperature distributions at slab corner and wide surface center compared with narrow surface center.Consequently,precipitated phases,particularly those located on the narrow surface,readily induce stress concentration and thus increase cracking tendency.A smaller precipitated phase size can reduce the stress concentration zone,while a more spherical shape can distribute surrounding stress along its surface and lower the internal stress within it,thereby decreasing the risk of slab cracking during continuous casting.The optimal precipitated phase exhibits a spherical or ellipsoidal shape with a major axis of less than 5µm,minimizing its potential to initiate cracks.
基金supported by the Application Technology of Automotive Steels(No.2021040300048)the National Natural Science Foundation of China(No.52304347)+2 种基金Hebei Provincial Natural Science Foundation(No.E2019501008),China Baowu Low Carbon Metallurgy Innovation Foundation(BWLCF202320)Natural Science Foundation of Liaoning Province(Nos.2023-MSBA-135 and 2023-BSBA-107)Fundamental Research Funds for the Central Universities(Nos.N2409008 and N2409006).
文摘The electromagnetic swirling flow in nozzle(EMSFN)technique is designed to mitigate the adverse effects of unstable and uneven flow within the submerged entry nozzle in continuous casting.Utilizing electromagnetic forces,EMSFN stabilizes the flow within the nozzle,leading to a more controlled flow in the mold.Numerical simulations were used to quantitatively analyze the magnetic and flow fields in a slab continuous casting system under EMSFN.Results indicate that EMSFN significantly stabilizes the outflow from the nozzle,with stability increasing with higher current intensity.At 10,000 Ampere-turns(At)of the coil,meniscus fluctuations were unstable.They stabilized at 13,000 At,with minimal changes observed beyond this point.The optimal current intensity for stable mold flow,at a casting speed of 1.56 m/min,is 13,000 At.These findings confirm the effectiveness of EMSFN in stabilizing the internal flow field of the slab mold and determining optimal operational current intensity.
文摘Drive-by techniques for bridge health monitoring have drawn increasing attention from researchers and practitioners,in the attempt to make bridge condition-based monitoring more cost-efficient.In this work,the authors propose a drive-by approach that takes advantage from bogie vertical accelerations to assess bridge health status.To do so,continuous wavelet transform is combined with multiple sparse autoencoders that allow for damage detection and localization across bridge span.According to authors’best knowledge,this is the first case in which an unsupervised technique,which relies on the use of sparse autoencoders,is used to localize damages.The bridge considered in this work is a Warren steel truss bridge,whose finite element model is referred to an actual structure,belonging to the Italian railway line.To investigate damage detection and localization performances,different operational variables are accounted for:train weight,forward speed and track irregularity evolution in time.Two configurations for the virtual measuring channels were investigated:as a result,better performances were obtained by exploiting the vertical accelerations of both the bogies of the leading coach instead of using only one single acceleration signal.
