This paper examines a model that combines vortex generators and leading-edge tubercles for controlling the laminar separation bubble(LSB)over an airfoil at low Reynolds numbers(Re).This new concept of passive flow con...This paper examines a model that combines vortex generators and leading-edge tubercles for controlling the laminar separation bubble(LSB)over an airfoil at low Reynolds numbers(Re).This new concept of passive flow control technique utilizing a tubercle and vortex generator(VG)close to the leading edge was analyzed numerically for a NACA0015 airfoil.In this study,the Shear Stress Transport(SST)turbulence model was employed in the numerical modelling.Numerical modelling was completed using the ANSYS-Fluent 18.2 solver.Analyses were conducted to investigate the flow pattern and understand the underlying LSB control phenomena that enabled the new passive flow control method to provide this significant performance benefit.The findings indicated that the new concept of passive flow control technique suppressed the formation of an LSB at the suction surface of the NACA0015 airfoil,resulting in a higher lift coefficient and improved aerodynamic performance.Improvements in LSB dynamics and aerodynamic performance through the passive flow control method lead to increased energy output and enhanced stability.展开更多
Rolling noise is produced by vibration of the wheels and track,induced by their combined surface roughness.It is important to know the relative contributions of the different sources,as this affects noise control stra...Rolling noise is produced by vibration of the wheels and track,induced by their combined surface roughness.It is important to know the relative contributions of the different sources,as this affects noise control strategies as well as acceptance testing of new rolling stock.Three different techniques are described that aim to use pass-by measurements to separate the wheel and track components of rolling noise.One is based on the TWINS model,which is tuned to measured track vibration.The second is based on the advanced transfer path analysis method,which provides an entirely experimental assessment.The third is based on the pass-by analysis method in combination with static vibroacoustic transfer functions which are obtained using a reciprocity method.The development of these methods is described and comparisons between them are presented using the results from three experimental measurement campaigns.These covered a metro train,a regional train and a high-speed train at a range of speeds.The various methods agree reasonably well in terms of overall trends,with moderate agreement in the mid-frequency region,and less consistent results at low and high frequency.展开更多
Objective:To explore the significance of continuing care in improving self-care ability and quality of life in patients with chronic obstructive pulmonary disease(COPD).Methods:A total of 60 COPD patients treated in o...Objective:To explore the significance of continuing care in improving self-care ability and quality of life in patients with chronic obstructive pulmonary disease(COPD).Methods:A total of 60 COPD patients treated in our department between June 2023 and June 2024 were randomly divided into control and observation groups.The control group received routine care,while the observation group received additional continuing care.Self-care ability and quality of life were compared between the two groups.Results:After the intervention,the observation group demonstrated higher self-care ability and quality of life scores compared to the control group(P<0.05).Conclusion:Continuing care for COPD patients has a positive impact on enhancing self-care ability and improving quality of life,making it worth recommending.展开更多
Traditional nanofiltration membranes face challenges such as membrane fouling and difficulties in achieving precise separation of small organic molecules.A promising solution to these issues is the preparation of thin...Traditional nanofiltration membranes face challenges such as membrane fouling and difficulties in achieving precise separation of small organic molecules.A promising solution to these issues is the preparation of thin-film nanocomposite membranes.In this study,Cu and Ag bimetals were incorporated into covalent organic frameworks to fabricate thin-film nanocomposite membranes.The hydrophilic monomer 1,3,5-tris(4-aminophenyl)benzene of covalent organic frameworks was introduced as a water phase monomer during interfacial polymerization to enhance the organic-inorganic compatibility.The incorporated covalent organic frameworks within the thin-film nanocomposite membrane loosened the selective layer,resulting in an enhanced permeability of 24.6 LMH bar^(-1).The membrane exhibited a rejection rate over 99.0%for Congo Red,Xylene Brilliant Cyanine G,and Reactive Blue,while exhibiting relatively low rejection rates of MgCl_(2) and NaCl.Moreover,the outstanding catalytic capability of the incorporated bimetals led to a 4-nitrophenol conversion rate of 84.38%,enabling simultaneous conversion and separation.The integration of covalent organic frameworks and bimetals also imparted robust antibacterial properties,significantly enhancing operational stability.In conclusion,the covalent organic framework-Cu/Ag-based thin-film nanocomposite membrane demonstrated superior catalytic and separation capabilities,presenting a promising alternative for advanced filtration applications.展开更多
Ultrasonic pulse-echo icing detectors currently lack sensitivity to the early stages of icing,failing to effectively identify the thickness of thin ice layers and issue timely ice formation warnings during flight.The ...Ultrasonic pulse-echo icing detectors currently lack sensitivity to the early stages of icing,failing to effectively identify the thickness of thin ice layers and issue timely ice formation warnings during flight.The thin ice layers at the initial stage of icing can result in the overlap and mixing of ultrasonic signals,posing a significant challenge for ice thickness identification.This paper initially simulates ultrasonic pulse-echo signals for ice layers of varying thicknesses using the finite element method.Subsequently,the blind source separation algorithm,Fast ICA,is utilized to separate the ultrasonic mixture signals at the early stages of icing,with a comparison of the signal separation effects of nonlinear functions G_(1),G_(2),and G_(3).The results indicate that the G_(2)nonlinear function exhibits poor stability in signal separation,leading to signal distortion during the process,thus favoring the use of G_(1)type and G_(3)type nonlinear functions.This paper further analyzes the intrinsic causes of the periodic fluctuations in the phase difference/time of flight curve through signal distribution and correlation features,and validates the feasibility of the algorithm through dynamic icing experiments,achieving effective identification of thin ice layer thickness during the initial stages of icing.展开更多
This study examines the reliability and validity of AI-generated scoring for continuation writing tasks.By comparing GPT-4 with eight experienced human raters across 21 student responses,it evaluates AI’s consistency...This study examines the reliability and validity of AI-generated scoring for continuation writing tasks.By comparing GPT-4 with eight experienced human raters across 21 student responses,it evaluates AI’s consistency,severity,and alignment with human scoring criteria.Results show that AI exhibits high self-consistency and adapts effectively to different scoring roles(e.g.,teacher vs.highstakes rater).However,AI scores were more lenient than human raters and demonstrated divergent evaluation focuses—prioritizing narrative coherence and emotional depth,while teachers emphasized linguistic accuracy and richness of detail.The findings suggest AI’s potential as a supplementary assessment tool,offering rapid,holistic feedback,but highlight the need for further calibration to align with educational standards.Implications include exploring hybrid evaluation models that leverage the strengths of both AI and human raters to achieve more equitable,efficient,and pedagogically meaningful writing assessments.展开更多
Continual learning fault diagnosis(CLFD)has gained growing interest in mechanical systems for its ability to accumulate and transfer knowledge in dynamic fault diagnosis scenarios.However,existing CLFD methods typical...Continual learning fault diagnosis(CLFD)has gained growing interest in mechanical systems for its ability to accumulate and transfer knowledge in dynamic fault diagnosis scenarios.However,existing CLFD methods typically assume balanced task distributions,neglecting the long-tailed nature of real-world fault occurrences,where certain faults dominate while others are rare.Due to the long-tailed distribution among different me-chanical conditions,excessive attention has been focused on the dominant type,leading to performance de-gradation in rarer types.In this paper,decoupling incremental classifier and representation learning(DICRL)is proposed to address the dual challenges of catastrophic forgetting introduced by incremental tasks and the bias in long-tailed CLFD(LT-CLFD).The core innovation lies in the structural decoupling of incremental classifier learning and representation learning.An instance-balanced sampling strategy is employed to learn more dis-criminative deep representations from the exemplars selected by the herding algorithm and new data.Then,the previous classifiers are frozen to prevent damage to representation learning during backward propagation.Cosine normalization classifier with learnable weight scaling is trained using a class-balanced sampling strategy to enhance classification accuracy.Experimental results demonstrate that DICRL outperforms existing continual learning methods across multiple benchmarks,demonstrating superior performance and robustness in both LT-CLFD and conventional CLFD.DICRL effectively tackles both catastrophic forgetting and long-tailed distribution in CLFD,enabling more reliable fault diagnosis in industrial applications.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
The dependence of interface structure and mechanical properties on the modulation layer thickness of VN/TiN−Ni nano-multilayered films deposited on Si substrates using a reactive magnetron sputtering technique was sys...The dependence of interface structure and mechanical properties on the modulation layer thickness of VN/TiN−Ni nano-multilayered films deposited on Si substrates using a reactive magnetron sputtering technique was systematically investigated. The films were characterized using X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, transmission electron microscopy, and nanoindentation. The results show that the TiN−Ni layer grows epitaxially on the VN layer, forming a coherent interface between the two sublayers. When the deposition time ratio of the two sublayers (TTiN−Ni꞉TVN) is 10꞉12, the films exhibit remarkable mechanical properties, with hardness, elastic modulus, and fracture toughness values of 25.9 GPa, 317 GPa, and 1.88 MPa·m^(1/2), respectively. Meanwhile, fracture toughness is improved by approximately 50% compared to the VN monolithic film. This enhancement is attributed to the coherent interface between the sublayers and the phase separation in the TiN−Ni layer.展开更多
Lithium(Li)dendrites,resulting from poor ion desolvation and transport behavior at the anode/electrolyte interface during electrodeposition,severely impede the practicality of Li metal anodes.Inspired by the transmemb...Lithium(Li)dendrites,resulting from poor ion desolvation and transport behavior at the anode/electrolyte interface during electrodeposition,severely impede the practicality of Li metal anodes.Inspired by the transmembrane cascade transport mechanism of biological ion pumps,we design a biomimetic dual-cascade separator(BDS)based on gradient pore core–shell Gd_(2)O_(3)@ZIF-7 nanoparticles to stabilize Li metal anodes.The mesoporous Gd_(2)O_(3)core,via Lewis acidic surface,weakens Li^(+) -solvent interactions,thereby reconstructing the solvation structure and achieving pre-desolvation.The microporous ZIF-7 shell then promotes final desolvation through strong confinement effect and N-rich site coordination,while its nanochannels homogenize Li^(+) transport.This synergistic meso/microporous gradient creates a unique dual-cascade effect for ion desolvation and transport.Consequently,BDS achieves a low desolvation energy barrier,a high Li^(+) transference number(0.71),and dendrite-free Li deposition.The average Coulombic efficiency rises from 72.7%to 98.4%,the cycling performance of the Li||Li symmetrical cell improves by 3.2 times,and the capacity retention of LiFePO_4(LFP)||Li full cell increases from 38.3%to73.4%after 500 cycles.This work offers a novel separator design concept,deepens Li deposition understanding,and guides separators from passive protection to active regulation.展开更多
Photocatalytic carbon dioxide reduction reaction(CO_(2)RR)is a carbon-neutral strategy to address global energy use and its impact on climate.Metal oxide and metal chalcogenide catalysts are the most investigated cata...Photocatalytic carbon dioxide reduction reaction(CO_(2)RR)is a carbon-neutral strategy to address global energy use and its impact on climate.Metal oxide and metal chalcogenide catalysts are the most investigated catalysts for photocatalytic CO_(2)RR.Unfortunately,low CO_(2)adsorption ability and limited active sites of metal oxide and metal chalcogenide catalysts for CO_(2)RR make them less competitive compared to their industrial counterparts.Inspired by applications of porphyrin-based metal-organic framework(MOF)catalysts for hydrogen evolution and photodynamic therapy,the investigations of these porphyrin-based MOFs,including pristine and composite porphyrin-based MOFs in photocatalytic CO_(2)RR,have attracted significant attention in the last five years due to their excellent CO_(2)adsorption capacities,high porosity,high stability,exceptional optoelectronic properties,and multi-functionality.However,due to the difference in photocatalytic CO_(2)RR,several critical issues need to be addressed to achieve the rational design of advanced porphyrin-based MOF photocatalysts to improve activity,selectivity,and stability for CO_(2)RR.Here,we review recent developments in the field of porphyrin-based MOF CO_(2)RR photocatalysts,along with critical issues,challenges,and perspectives concerning porphyrin-based MOF catalysts for photocatalytic CO_(2)RR.展开更多
Taking the view that pro-environmental behaviors can have spillover effects,this study examines how household waste separation(an environmental behavior with a high degree of difficulty)impacts consumers’water saving...Taking the view that pro-environmental behaviors can have spillover effects,this study examines how household waste separation(an environmental behavior with a high degree of difficulty)impacts consumers’water saving efforts(an environmental behavior with a low degree of difficulty).We assess the mediating effects of self-efficacy and ego depletion in this relationship and the moderating effect of the need for self-determination in the mediated relationships.The results show separating household waste significantly enhances consumers’water-saving efforts.Both self-efficacy and ego depletion partially mediate the relationship between household waste separation and efforts to reduce water consumption.Specifically,if consumers engage in pro environmental behaviors based on their internal,rather than external sense of moral identity,their sense of self-efficacy increases after separating household,which motivates them to engage in subsequent water-saving behaviors.In addition,consumers’sense of ego depletion declines when they engage in household waste separation,which increases subsequent water-saving behavior.Compared to low-level self-determination needs,high-level self-determination needs weaken the positive impact of household waste separation on consumers’perceived self-efficacy,but strengthens the negative impact of household waste separation on consumers’perceived ego depletion and promotes subsequent water-saving behavior.These findings suggest policymakers should pay attention to the spillover effects pro-environmental behaviors and use household waste separation policies to promote other pro-environmental behaviors such as reducing water consumption.展开更多
With the legislative development,the organic and inorganic composition separation has become the primary requirement for sewer sediment disposal,however the relevant technology has been rarely reported and the driving...With the legislative development,the organic and inorganic composition separation has become the primary requirement for sewer sediment disposal,however the relevant technology has been rarely reported and the driving mechanism was still unclear.In this study,direct disintegration of biopolymers and indirect broken of connection point were investigated on the hydrolysis and component separation.Three typical sewer sediment treatment approaches,i.e.,alkaline,thermal and cation exchange treatments were proposed,which represented the hydrolysis-driving forces of chemical hydrolysis,physical hydrolysis and innovative cation bridging break-age.The results showed that the organic and inorganic separation rates of sewer sediment driven by alkaline,thermal and cation exchange treatments reached 21.26%,23.80%,and 19.56%-48.0%,respectively,compared to 4.43%in control.The secondary structure of proteins was disrupted,transitioning from𝛼α-helix to𝛽β-turn and random coil.Meanwhile,much biopolymers were released from solid to the liquid phase.From thermody-namic perspective,sewer sediment deposition was controlled by short-range interfacial interactions described by extended Derjaguin-Landau-Verwey-Overbeek theory.Additionally,the separation of organic and inorganic components was positively correlated with the thermodynamic parameters(Corr=0.87),highlighted the robust-ness of various driving forces.And the flocculation energy barriers were 2.40(alkaline),1.60 times(thermal),and 4.02–4.97 times(cation exchange)compared to control group.The findings revealed the contrition differ-ence of direct disintegration of gelatinous biopolymers and indirect breakage of composition connection sites in sediment composition separation,filling the critical gaps in understanding the specific mechanisms of sediment biopolymer disintegration and intermolecular connection breakage.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
The efficient flotation separation of rare earth elements(REEs)from gangue minerals is crucial in mineral processing.This study synthesized a quaternary ammonium salt ionic liquid collector,tetrabutylammonium salicylh...The efficient flotation separation of rare earth elements(REEs)from gangue minerals is crucial in mineral processing.This study synthesized a quaternary ammonium salt ionic liquid collector,tetrabutylammonium salicylhydroxamate(T-S),and investigated its performance in separating bastnaesite and fluorite.T-S was synthesized from salicylhydroxamic acid(SHA)and tetrabutylammonium chloride(TBAC),and its molecular structure was characterized using Fourier transform infrared(FTIR)spectroscopy.Microflotation tests indicate that T-S outperforms SHA and TBAC in both collecting ability and selectivity for bastnaesite.Adsorption,zeta potential,and infrared spectroscopy measurements reveal that T-S exhibits stronger adsorption on bastnaesite compared to SHA and TBAC.X-ray photoelectron spectroscopy(XPS)and molecular dynamics simulations(MDS)results confirm that chemical adsorption occurs between Ce on the bastnaesite surface and the-C(=O)NHOH groups of T-S.Moreover,the interaction between T-S and the bastnaesite surface is stronger than that with the fluorite surface.This work provides valuable insights for designing ionic liquid collectors for the flotation separation of bastnaesite and fluorite.展开更多
Methods of quantum information processing often appear in terms of specially selected states.For example,mutually unbiased bases(MUBs)and symmetric informationally complete measurements are widely applied.Finite frame...Methods of quantum information processing often appear in terms of specially selected states.For example,mutually unbiased bases(MUBs)and symmetric informationally complete measurements are widely applied.Finite frames have found use in many areas including quantum information.Due to its specific inner structure,a single equiangular tight frame(ETF)allows one to formulate criteria to detect non-classical correlations.This study aims to approach entanglement detection with the use of mutually unbiased ETFs.Such frames are an interesting generalization of widely recognized MUBs.It still uses rank-one operators,but the number of outcomes can exceed the dimensionality.Several approaches are considered including separability criteria and entanglement witnesses.Separability criteria for multipartite systems are finally obtained.展开更多
Selective extraction of precious metals from urban mines plays a crucial role in mitigating the risk of depletion of precious metal resources and reducing waste pollution.However,a major obstacle in precious metal ext...Selective extraction of precious metals from urban mines plays a crucial role in mitigating the risk of depletion of precious metal resources and reducing waste pollution.However,a major obstacle in precious metal extraction lies in the difficulty of distinguishing the subtle differences in the physicochemical characteristics between them,especially gold and palladium.Herein,a proton-driven separation system was presented for cascade recovery of gold and palladium from waste-printed circuit boards(W-PCBs)leachate using poly(amidoxime)(PAO)hydrogel.This exhibits an ultra-high capacity,extra-fast rate,and excellent selectivity for the extraction of Au(Ⅲ)and Pd(Ⅱ).Notably,the separation of Au(Ⅲ)and Pd(Ⅱ)can be achieved with high selectivity at pH=0,resulting in a remarkable separation factor of k_(Au(Ⅲ)/Pd(Ⅱ))=36.5.This was demonstrated to originate from the differential mechanism of PAO hydrogel for the capture of Au(Ⅲ)and Pd(Ⅱ)under proton-mediated conditions.Drawing inspiration from the mechanism,the proton-driven cascade recovery system demonstrates remarkable efficiency in sequentially recovering 99.92%of gold and 99.05%of palladium from W-PCBs acid leachate.This research opens up a strategy to precisely separate and recover precious metals from e-waste of urban mines.展开更多
Lithium–sulfur batteries(LSBs)suffer from sluggish lithium polysulfides(LiPS)conversion and severe interfacial instability,which limit their rate performance and cycle life.Herein,we report a multifunctional interlay...Lithium–sulfur batteries(LSBs)suffer from sluggish lithium polysulfides(LiPS)conversion and severe interfacial instability,which limit their rate performance and cycle life.Herein,we report a multifunctional interlayer comprising Mo_(2)C nanoparticles confined within a nitrogen-and phosphorus-codoped amorphous carbon matrix supported on reduced graphene oxide(MNPG).H3PMo12O40 was chosen as a final polyoxometalate(POM)precursor because it was transformed into the tubular nanoparticles,while Na_(3)PMo_(12)O_(4)0 was converted to irregular micrometer-sized particles.In particular,the hierarchical structure of MNPG is synthesized via electrostatic self-assembly of POM and pyrrole on graphene oxide,followed by thermal transformation.The embedded Mo_(2)C domains act as efficient redox mediators that accelerate LiPS conversion,while the polar doped carbon shell suppresses parasitic reactions and facilitates ion transport.Consequently,the MNPG-coated separator allows LSBs to deliver a high specific capacity of 1549 mAh g^(-1) at 0.1 C and 802 mAh g^(-1) at 5.0 C,along with 81.1%capacity retention after 200 cycles.This study provides a straightforward and effective interfacial engineering strategy that combines redox-mediating domains and transport regulation within a unified structure to overcome key bottlenecks of LSBs.展开更多
Local resonant acoustic metamaterials have broad applications in sound insulation,yet their single-configuration designs often exhibit limited and discontinuous bandgap widths,hindering full-frequency noise attenuatio...Local resonant acoustic metamaterials have broad applications in sound insulation,yet their single-configuration designs often exhibit limited and discontinuous bandgap widths,hindering full-frequency noise attenuation across the human auditory range.This study presents a double-phase fidget-spinner-shaped acoustic metamaterial(DFAM),specifically designed to achieve an ultra-broad,low-frequency continuous bandgap by means of synergistic structural optimization,enabling effective and robust control of audible noise.Based on Bloch's theorem and the finite element method,the dispersion relation of the DFAM structure is calculated and verified by the transmission loss curves.The propagation characteristics of sound waves within the structure are further analyzed for noise frequencies that fall within the passband.The influence of the geometric and physical parameters on the bandgap is investigated,and the corresponding transmission loss in the propagation direction is further calculated.A hybrid collaborative design strategy,leveraging multi-parameter optimization and bandgap complementarity,is developed to construct a metastructure with continuous bandgap coverage from 20 Hz to 1000 Hz.The resulting metastructure demonstrates exceptional broadband noise attenuation,achieving a total bandgap width of 876.3 Hz(87.63% of the target range)with the transmission loss up to-762.78 d B in a three-periodic arrangement.The simulation and experimental results for the transmission loss of the DFAM metastructure show strong agreement in the low-frequency range.This work provides a novel framework for designing ultra-wide low-frequency continuous bandgap metastructures,offering significant potential for noise mitigation in complex environments.展开更多
基金the Scientific Research Projects Unit of Erciyes University under contract no:FDS-2022-11532 and FOA-2025-14773.
文摘This paper examines a model that combines vortex generators and leading-edge tubercles for controlling the laminar separation bubble(LSB)over an airfoil at low Reynolds numbers(Re).This new concept of passive flow control technique utilizing a tubercle and vortex generator(VG)close to the leading edge was analyzed numerically for a NACA0015 airfoil.In this study,the Shear Stress Transport(SST)turbulence model was employed in the numerical modelling.Numerical modelling was completed using the ANSYS-Fluent 18.2 solver.Analyses were conducted to investigate the flow pattern and understand the underlying LSB control phenomena that enabled the new passive flow control method to provide this significant performance benefit.The findings indicated that the new concept of passive flow control technique suppressed the formation of an LSB at the suction surface of the NACA0015 airfoil,resulting in a higher lift coefficient and improved aerodynamic performance.Improvements in LSB dynamics and aerodynamic performance through the passive flow control method lead to increased energy output and enhanced stability.
基金supported by the TRANSIT project(funded by EU Horizon 2020 and the Europe’s Rail Joint Undertaking under grant agreement 881771).
文摘Rolling noise is produced by vibration of the wheels and track,induced by their combined surface roughness.It is important to know the relative contributions of the different sources,as this affects noise control strategies as well as acceptance testing of new rolling stock.Three different techniques are described that aim to use pass-by measurements to separate the wheel and track components of rolling noise.One is based on the TWINS model,which is tuned to measured track vibration.The second is based on the advanced transfer path analysis method,which provides an entirely experimental assessment.The third is based on the pass-by analysis method in combination with static vibroacoustic transfer functions which are obtained using a reciprocity method.The development of these methods is described and comparisons between them are presented using the results from three experimental measurement campaigns.These covered a metro train,a regional train and a high-speed train at a range of speeds.The various methods agree reasonably well in terms of overall trends,with moderate agreement in the mid-frequency region,and less consistent results at low and high frequency.
基金Baoding Science and Technology Bureau Project“Study on the Impact of Continuing Care on Self-Care Ability and Quality of Life in COPD Patients”(Project No.2441ZF276)。
文摘Objective:To explore the significance of continuing care in improving self-care ability and quality of life in patients with chronic obstructive pulmonary disease(COPD).Methods:A total of 60 COPD patients treated in our department between June 2023 and June 2024 were randomly divided into control and observation groups.The control group received routine care,while the observation group received additional continuing care.Self-care ability and quality of life were compared between the two groups.Results:After the intervention,the observation group demonstrated higher self-care ability and quality of life scores compared to the control group(P<0.05).Conclusion:Continuing care for COPD patients has a positive impact on enhancing self-care ability and improving quality of life,making it worth recommending.
基金sponsored by the National Natural Science Foundation of China(Grant No.NSFC-22378160 and U23A20688).
文摘Traditional nanofiltration membranes face challenges such as membrane fouling and difficulties in achieving precise separation of small organic molecules.A promising solution to these issues is the preparation of thin-film nanocomposite membranes.In this study,Cu and Ag bimetals were incorporated into covalent organic frameworks to fabricate thin-film nanocomposite membranes.The hydrophilic monomer 1,3,5-tris(4-aminophenyl)benzene of covalent organic frameworks was introduced as a water phase monomer during interfacial polymerization to enhance the organic-inorganic compatibility.The incorporated covalent organic frameworks within the thin-film nanocomposite membrane loosened the selective layer,resulting in an enhanced permeability of 24.6 LMH bar^(-1).The membrane exhibited a rejection rate over 99.0%for Congo Red,Xylene Brilliant Cyanine G,and Reactive Blue,while exhibiting relatively low rejection rates of MgCl_(2) and NaCl.Moreover,the outstanding catalytic capability of the incorporated bimetals led to a 4-nitrophenol conversion rate of 84.38%,enabling simultaneous conversion and separation.The integration of covalent organic frameworks and bimetals also imparted robust antibacterial properties,significantly enhancing operational stability.In conclusion,the covalent organic framework-Cu/Ag-based thin-film nanocomposite membrane demonstrated superior catalytic and separation capabilities,presenting a promising alternative for advanced filtration applications.
基金supported by the National Natural Science Foundation of China(Key Program)(Nos.12132019,12172372)National Science and Technology Major Project of China(No.J2019-Ⅲ-0017)。
文摘Ultrasonic pulse-echo icing detectors currently lack sensitivity to the early stages of icing,failing to effectively identify the thickness of thin ice layers and issue timely ice formation warnings during flight.The thin ice layers at the initial stage of icing can result in the overlap and mixing of ultrasonic signals,posing a significant challenge for ice thickness identification.This paper initially simulates ultrasonic pulse-echo signals for ice layers of varying thicknesses using the finite element method.Subsequently,the blind source separation algorithm,Fast ICA,is utilized to separate the ultrasonic mixture signals at the early stages of icing,with a comparison of the signal separation effects of nonlinear functions G_(1),G_(2),and G_(3).The results indicate that the G_(2)nonlinear function exhibits poor stability in signal separation,leading to signal distortion during the process,thus favoring the use of G_(1)type and G_(3)type nonlinear functions.This paper further analyzes the intrinsic causes of the periodic fluctuations in the phase difference/time of flight curve through signal distribution and correlation features,and validates the feasibility of the algorithm through dynamic icing experiments,achieving effective identification of thin ice layer thickness during the initial stages of icing.
文摘This study examines the reliability and validity of AI-generated scoring for continuation writing tasks.By comparing GPT-4 with eight experienced human raters across 21 student responses,it evaluates AI’s consistency,severity,and alignment with human scoring criteria.Results show that AI exhibits high self-consistency and adapts effectively to different scoring roles(e.g.,teacher vs.highstakes rater).However,AI scores were more lenient than human raters and demonstrated divergent evaluation focuses—prioritizing narrative coherence and emotional depth,while teachers emphasized linguistic accuracy and richness of detail.The findings suggest AI’s potential as a supplementary assessment tool,offering rapid,holistic feedback,but highlight the need for further calibration to align with educational standards.Implications include exploring hybrid evaluation models that leverage the strengths of both AI and human raters to achieve more equitable,efficient,and pedagogically meaningful writing assessments.
基金Supported by National Natural Science Foundation of China(Grant No.52272440)Suzhou Science Foundation(Grant Nos.SYG202323,ZXL2022027).
文摘Continual learning fault diagnosis(CLFD)has gained growing interest in mechanical systems for its ability to accumulate and transfer knowledge in dynamic fault diagnosis scenarios.However,existing CLFD methods typically assume balanced task distributions,neglecting the long-tailed nature of real-world fault occurrences,where certain faults dominate while others are rare.Due to the long-tailed distribution among different me-chanical conditions,excessive attention has been focused on the dominant type,leading to performance de-gradation in rarer types.In this paper,decoupling incremental classifier and representation learning(DICRL)is proposed to address the dual challenges of catastrophic forgetting introduced by incremental tasks and the bias in long-tailed CLFD(LT-CLFD).The core innovation lies in the structural decoupling of incremental classifier learning and representation learning.An instance-balanced sampling strategy is employed to learn more dis-criminative deep representations from the exemplars selected by the herding algorithm and new data.Then,the previous classifiers are frozen to prevent damage to representation learning during backward propagation.Cosine normalization classifier with learnable weight scaling is trained using a class-balanced sampling strategy to enhance classification accuracy.Experimental results demonstrate that DICRL outperforms existing continual learning methods across multiple benchmarks,demonstrating superior performance and robustness in both LT-CLFD and conventional CLFD.DICRL effectively tackles both catastrophic forgetting and long-tailed distribution in CLFD,enabling more reliable fault diagnosis in industrial applications.
文摘Background:Continuous care for children with enterostomy and their families has been gaining popularity in China.Objective:To evaluate the feasibility of continuous care for children with enterostomy and their families in China.Methods:The PubMed,Web of Science,Embase,Cochrane Library,EBSCO,CNKI,CBM,VIP,and WanFang were searched for clinical trials until December 30,2025.Two reviewers independently searched articles,evaluated quality and extracted data.This review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses(PRISMA).Results:33 studies involving 2774 participants were included.The meta-analysis showed that continuous care strategy can significantly reduce the incidence of complications in children with enterostomy(OR=0.20,95%CI=0.16-0.26,p<0.001,I2=0%),effectively improve the family caregiver ability for enterostomy(MD=-10.34,95%CI=-13.82 to-6.85,p<0.001,I2=99%),shorten the time for family members to replace stoma bags(MD=-13.57,95%CI=-19.66 to-7.49,p<0.001,I2=100%),and alleviate negative emotions such as anxiety(SMD=-1.80,95%CI=-2.36 to-1.23,p<0.001,I2=92%)and depression(SMD=-1.54,95%CI=-2.04 to-1.04,p<0.001,I2=89%)in the families of the affected children.Conclusions:Continuous care can reduce complications of enterostomy in children,improve the family caregiver ability for enterostomy and alleviate negative emotions of family members such as anxiety and depression.
基金financially supported by the National Natural Science Foundation of China(No.51971148)the Key Project Foundation of Hanjiang Normal University,China(No.XJ2024A09)+1 种基金the Excellent Young and Middle-aged Science and Technology Innovation Team Project in Higher Education Institutions of Hubei Province,China(No.T2020024)the Shanghai Engineering Research Center of High-Performance Medical Device Materials,China(No.20DZ2255500)。
文摘The dependence of interface structure and mechanical properties on the modulation layer thickness of VN/TiN−Ni nano-multilayered films deposited on Si substrates using a reactive magnetron sputtering technique was systematically investigated. The films were characterized using X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, transmission electron microscopy, and nanoindentation. The results show that the TiN−Ni layer grows epitaxially on the VN layer, forming a coherent interface between the two sublayers. When the deposition time ratio of the two sublayers (TTiN−Ni꞉TVN) is 10꞉12, the films exhibit remarkable mechanical properties, with hardness, elastic modulus, and fracture toughness values of 25.9 GPa, 317 GPa, and 1.88 MPa·m^(1/2), respectively. Meanwhile, fracture toughness is improved by approximately 50% compared to the VN monolithic film. This enhancement is attributed to the coherent interface between the sublayers and the phase separation in the TiN−Ni layer.
基金the financial support from the National Natural Science Foundation of China(22408182)the Young Talents of Science and Technology in Universities of Inner Mongolia Autonomous Region(NJYT24024)the Natural Science Foundation of Inner Mongolia Autonomous Region(2023QN02007 and 2025QN02009)。
文摘Lithium(Li)dendrites,resulting from poor ion desolvation and transport behavior at the anode/electrolyte interface during electrodeposition,severely impede the practicality of Li metal anodes.Inspired by the transmembrane cascade transport mechanism of biological ion pumps,we design a biomimetic dual-cascade separator(BDS)based on gradient pore core–shell Gd_(2)O_(3)@ZIF-7 nanoparticles to stabilize Li metal anodes.The mesoporous Gd_(2)O_(3)core,via Lewis acidic surface,weakens Li^(+) -solvent interactions,thereby reconstructing the solvation structure and achieving pre-desolvation.The microporous ZIF-7 shell then promotes final desolvation through strong confinement effect and N-rich site coordination,while its nanochannels homogenize Li^(+) transport.This synergistic meso/microporous gradient creates a unique dual-cascade effect for ion desolvation and transport.Consequently,BDS achieves a low desolvation energy barrier,a high Li^(+) transference number(0.71),and dendrite-free Li deposition.The average Coulombic efficiency rises from 72.7%to 98.4%,the cycling performance of the Li||Li symmetrical cell improves by 3.2 times,and the capacity retention of LiFePO_4(LFP)||Li full cell increases from 38.3%to73.4%after 500 cycles.This work offers a novel separator design concept,deepens Li deposition understanding,and guides separators from passive protection to active regulation.
基金financially supported by the National Natural Science Foundation of China(No.22305009)the Science and Technology Development Fund,Macao SAR(File no.FDCT-0125/2022/A and FDCT-0006/2023/RIB1)Hong Kong Research Grant Council(RGC)General Research Fund(GRF)City U 11305419,11306920,CityU 11308721,CityU 11316522,and SIRG7020022。
文摘Photocatalytic carbon dioxide reduction reaction(CO_(2)RR)is a carbon-neutral strategy to address global energy use and its impact on climate.Metal oxide and metal chalcogenide catalysts are the most investigated catalysts for photocatalytic CO_(2)RR.Unfortunately,low CO_(2)adsorption ability and limited active sites of metal oxide and metal chalcogenide catalysts for CO_(2)RR make them less competitive compared to their industrial counterparts.Inspired by applications of porphyrin-based metal-organic framework(MOF)catalysts for hydrogen evolution and photodynamic therapy,the investigations of these porphyrin-based MOFs,including pristine and composite porphyrin-based MOFs in photocatalytic CO_(2)RR,have attracted significant attention in the last five years due to their excellent CO_(2)adsorption capacities,high porosity,high stability,exceptional optoelectronic properties,and multi-functionality.However,due to the difference in photocatalytic CO_(2)RR,several critical issues need to be addressed to achieve the rational design of advanced porphyrin-based MOF photocatalysts to improve activity,selectivity,and stability for CO_(2)RR.Here,we review recent developments in the field of porphyrin-based MOF CO_(2)RR photocatalysts,along with critical issues,challenges,and perspectives concerning porphyrin-based MOF catalysts for photocatalytic CO_(2)RR.
基金supported by the National Social Science Fund of China[Grant No.25BGL131].
文摘Taking the view that pro-environmental behaviors can have spillover effects,this study examines how household waste separation(an environmental behavior with a high degree of difficulty)impacts consumers’water saving efforts(an environmental behavior with a low degree of difficulty).We assess the mediating effects of self-efficacy and ego depletion in this relationship and the moderating effect of the need for self-determination in the mediated relationships.The results show separating household waste significantly enhances consumers’water-saving efforts.Both self-efficacy and ego depletion partially mediate the relationship between household waste separation and efforts to reduce water consumption.Specifically,if consumers engage in pro environmental behaviors based on their internal,rather than external sense of moral identity,their sense of self-efficacy increases after separating household,which motivates them to engage in subsequent water-saving behaviors.In addition,consumers’sense of ego depletion declines when they engage in household waste separation,which increases subsequent water-saving behavior.Compared to low-level self-determination needs,high-level self-determination needs weaken the positive impact of household waste separation on consumers’perceived self-efficacy,but strengthens the negative impact of household waste separation on consumers’perceived ego depletion and promotes subsequent water-saving behavior.These findings suggest policymakers should pay attention to the spillover effects pro-environmental behaviors and use household waste separation policies to promote other pro-environmental behaviors such as reducing water consumption.
基金supported by Shaanxi Key Research and Development Program(No.2024SF-YBXM-546)the National Natural Science Foundation of China(No.52470161)the State Key Laboratory of Pollution Control and Resource Reuse Foundation(No.PCRRF21007).
文摘With the legislative development,the organic and inorganic composition separation has become the primary requirement for sewer sediment disposal,however the relevant technology has been rarely reported and the driving mechanism was still unclear.In this study,direct disintegration of biopolymers and indirect broken of connection point were investigated on the hydrolysis and component separation.Three typical sewer sediment treatment approaches,i.e.,alkaline,thermal and cation exchange treatments were proposed,which represented the hydrolysis-driving forces of chemical hydrolysis,physical hydrolysis and innovative cation bridging break-age.The results showed that the organic and inorganic separation rates of sewer sediment driven by alkaline,thermal and cation exchange treatments reached 21.26%,23.80%,and 19.56%-48.0%,respectively,compared to 4.43%in control.The secondary structure of proteins was disrupted,transitioning from𝛼α-helix to𝛽β-turn and random coil.Meanwhile,much biopolymers were released from solid to the liquid phase.From thermody-namic perspective,sewer sediment deposition was controlled by short-range interfacial interactions described by extended Derjaguin-Landau-Verwey-Overbeek theory.Additionally,the separation of organic and inorganic components was positively correlated with the thermodynamic parameters(Corr=0.87),highlighted the robust-ness of various driving forces.And the flocculation energy barriers were 2.40(alkaline),1.60 times(thermal),and 4.02–4.97 times(cation exchange)compared to control group.The findings revealed the contrition differ-ence of direct disintegration of gelatinous biopolymers and indirect breakage of composition connection sites in sediment composition separation,filling the critical gaps in understanding the specific mechanisms of sediment biopolymer disintegration and intermolecular connection breakage.
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.
基金Project supported by the National Key Research and Development Program of China(2022YFC2905800)National Natural Science Foundation of China(52374276,52274269)+2 种基金Yunnan Fundamental Re search Projects(202401AS070051)the Natural Science Foundation of Hubei Province of China(2024AFD123)Young Elite Scientists Sponsorship Program by CAST(YESS20200276)。
文摘The efficient flotation separation of rare earth elements(REEs)from gangue minerals is crucial in mineral processing.This study synthesized a quaternary ammonium salt ionic liquid collector,tetrabutylammonium salicylhydroxamate(T-S),and investigated its performance in separating bastnaesite and fluorite.T-S was synthesized from salicylhydroxamic acid(SHA)and tetrabutylammonium chloride(TBAC),and its molecular structure was characterized using Fourier transform infrared(FTIR)spectroscopy.Microflotation tests indicate that T-S outperforms SHA and TBAC in both collecting ability and selectivity for bastnaesite.Adsorption,zeta potential,and infrared spectroscopy measurements reveal that T-S exhibits stronger adsorption on bastnaesite compared to SHA and TBAC.X-ray photoelectron spectroscopy(XPS)and molecular dynamics simulations(MDS)results confirm that chemical adsorption occurs between Ce on the bastnaesite surface and the-C(=O)NHOH groups of T-S.Moreover,the interaction between T-S and the bastnaesite surface is stronger than that with the fluorite surface.This work provides valuable insights for designing ionic liquid collectors for the flotation separation of bastnaesite and fluorite.
文摘Methods of quantum information processing often appear in terms of specially selected states.For example,mutually unbiased bases(MUBs)and symmetric informationally complete measurements are widely applied.Finite frames have found use in many areas including quantum information.Due to its specific inner structure,a single equiangular tight frame(ETF)allows one to formulate criteria to detect non-classical correlations.This study aims to approach entanglement detection with the use of mutually unbiased ETFs.Such frames are an interesting generalization of widely recognized MUBs.It still uses rank-one operators,but the number of outcomes can exceed the dimensionality.Several approaches are considered including separability criteria and entanglement witnesses.Separability criteria for multipartite systems are finally obtained.
基金supported by the National Natural Science Foundation of China grant nos.52470149(P.H.Shao)and 52125002(X.B.Luo)the National Key Research and Development Program of China grant no.2023YFC3905903(P.H.Shao)Nanchang Hangkong University Doctoral Start-up Fund grant no.EA202502100(Y.Y.Zhou).
文摘Selective extraction of precious metals from urban mines plays a crucial role in mitigating the risk of depletion of precious metal resources and reducing waste pollution.However,a major obstacle in precious metal extraction lies in the difficulty of distinguishing the subtle differences in the physicochemical characteristics between them,especially gold and palladium.Herein,a proton-driven separation system was presented for cascade recovery of gold and palladium from waste-printed circuit boards(W-PCBs)leachate using poly(amidoxime)(PAO)hydrogel.This exhibits an ultra-high capacity,extra-fast rate,and excellent selectivity for the extraction of Au(Ⅲ)and Pd(Ⅱ).Notably,the separation of Au(Ⅲ)and Pd(Ⅱ)can be achieved with high selectivity at pH=0,resulting in a remarkable separation factor of k_(Au(Ⅲ)/Pd(Ⅱ))=36.5.This was demonstrated to originate from the differential mechanism of PAO hydrogel for the capture of Au(Ⅲ)and Pd(Ⅱ)under proton-mediated conditions.Drawing inspiration from the mechanism,the proton-driven cascade recovery system demonstrates remarkable efficiency in sequentially recovering 99.92%of gold and 99.05%of palladium from W-PCBs acid leachate.This research opens up a strategy to precisely separate and recover precious metals from e-waste of urban mines.
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korea government(MSIT)(no.RS-2023-00217581)a grant(RS-2024-00470023)from the Materials and Components Technology Development(R&D)Project funded by the Ministry of Trade,Industry and Energy of the Republic of Korea.
文摘Lithium–sulfur batteries(LSBs)suffer from sluggish lithium polysulfides(LiPS)conversion and severe interfacial instability,which limit their rate performance and cycle life.Herein,we report a multifunctional interlayer comprising Mo_(2)C nanoparticles confined within a nitrogen-and phosphorus-codoped amorphous carbon matrix supported on reduced graphene oxide(MNPG).H3PMo12O40 was chosen as a final polyoxometalate(POM)precursor because it was transformed into the tubular nanoparticles,while Na_(3)PMo_(12)O_(4)0 was converted to irregular micrometer-sized particles.In particular,the hierarchical structure of MNPG is synthesized via electrostatic self-assembly of POM and pyrrole on graphene oxide,followed by thermal transformation.The embedded Mo_(2)C domains act as efficient redox mediators that accelerate LiPS conversion,while the polar doped carbon shell suppresses parasitic reactions and facilitates ion transport.Consequently,the MNPG-coated separator allows LSBs to deliver a high specific capacity of 1549 mAh g^(-1) at 0.1 C and 802 mAh g^(-1) at 5.0 C,along with 81.1%capacity retention after 200 cycles.This study provides a straightforward and effective interfacial engineering strategy that combines redox-mediating domains and transport regulation within a unified structure to overcome key bottlenecks of LSBs.
基金Project supported by the National Natural Science Foundation of China(No.12572020)the Key Project of Natural Science Foundation of Hebei Province of China(No.A2023210064)。
文摘Local resonant acoustic metamaterials have broad applications in sound insulation,yet their single-configuration designs often exhibit limited and discontinuous bandgap widths,hindering full-frequency noise attenuation across the human auditory range.This study presents a double-phase fidget-spinner-shaped acoustic metamaterial(DFAM),specifically designed to achieve an ultra-broad,low-frequency continuous bandgap by means of synergistic structural optimization,enabling effective and robust control of audible noise.Based on Bloch's theorem and the finite element method,the dispersion relation of the DFAM structure is calculated and verified by the transmission loss curves.The propagation characteristics of sound waves within the structure are further analyzed for noise frequencies that fall within the passband.The influence of the geometric and physical parameters on the bandgap is investigated,and the corresponding transmission loss in the propagation direction is further calculated.A hybrid collaborative design strategy,leveraging multi-parameter optimization and bandgap complementarity,is developed to construct a metastructure with continuous bandgap coverage from 20 Hz to 1000 Hz.The resulting metastructure demonstrates exceptional broadband noise attenuation,achieving a total bandgap width of 876.3 Hz(87.63% of the target range)with the transmission loss up to-762.78 d B in a three-periodic arrangement.The simulation and experimental results for the transmission loss of the DFAM metastructure show strong agreement in the low-frequency range.This work provides a novel framework for designing ultra-wide low-frequency continuous bandgap metastructures,offering significant potential for noise mitigation in complex environments.
