As a multidisciplinary phenomenon,panel aeroelasticity in shock-dominated flow is featured by two primary interactions:Fluid-Structure Interactions(FSIs)and Shock-Boundary Layer Interactions(SBLIs).The former raises s...As a multidisciplinary phenomenon,panel aeroelasticity in shock-dominated flow is featured by two primary interactions:Fluid-Structure Interactions(FSIs)and Shock-Boundary Layer Interactions(SBLIs).The former raises structural concerns,and the latter is of aerodynamic interest.Thus,panel aeroelasticity in shock-dominated flow represents a vital topic for the development and optimization of supersonic vehicles and propulsion systems.This review systematically summarizes recent advances in the methodologies applied to capture structural and fluid dynamics,including theoretical models,numerical simulations,and wind tunnel experiments.The application of data-driven modal decomposition,an advanced technique to extract physically crucial features,on the topic is introduced.From the perspective of FSIs,the distinctive aeroelastic behaviors in shock-dominated flow,including hysteresis phenomena and nonlinear responses,are highlighted.From the perspective of SBLIs,the modifications in their spatial and temporal characteristics imposed by the aeroelastic responses are emphasized.Motivated by the interaction between the shock waves and structural response,different strategies have been proposed to implement aeroelastic suppression and shock control,which have the potential to enhance structural safety and aerodynamic performance in the next generation of high-speed flight vehicles.展开更多
We present a high performance modularly-built open-source software-OpenIFEM.OpenIFEM is a C++implementation of the modified immersed finite element method(mIFEM)to solve fluid-structure interaction(FSI)problems.This s...We present a high performance modularly-built open-source software-OpenIFEM.OpenIFEM is a C++implementation of the modified immersed finite element method(mIFEM)to solve fluid-structure interaction(FSI)problems.This software is modularly built to perform multiple tasks including fluid dynamics(incompressible and slightly compressible fluid models),linear and nonlinear solid mechanics,and fully coupled fluid-structure interactions.Most of open-source software packages are restricted to certain discretization methods;some are under-tested,under-documented,and lack modularity as well as extensibility.OpenIFEM is designed and built to include a set of generic classes for users to adapt so that any fluid and solid solvers can be coupled through the FSI algorithm.In addition,the package utilizes well-developed and tested libraries.It also comes with standard test cases that serve as software and algorithm validation.The software can be built on cross-platform,i.e.,Linux,Windows,and Mac OS,using CMake.Efficient parallelization is also implemented for high-performance computing for large-sized problems.OpenIFEM is documented using Doxygen and publicly available to download on GitHub.It is expected to benefit the future development of FSI algorithms and be applied to a variety of FSI applications.展开更多
In the experimental investigation of fluid-structure interactions regarding the undulatory motion like flag flapping or fish swimming,solving the force distribution on the flexible body stands as an indispensable ende...In the experimental investigation of fluid-structure interactions regarding the undulatory motion like flag flapping or fish swimming,solving the force distribution on the flexible body stands as an indispensable endeavor to gain insights into the underlying dynamic mechanisms.However,the solving process entails high-order numerical derivatives of experimental data,which poses a formidable challenge for experimental studies on fluid-structure interactions,given that the measurement noise inherent in experimental data renders the problem ill-posed.The commonly practiced regularization methods for numerical derivatives are feeble to tackle the fourth-order derivative associated with the bending force;those methods,in particular,require predetermined parameters about the unknown noise.We introduce here an empirical regularization method founded upon the kernel-term modification in the frequency domain,notably capable of determining the fourth derivative of experimental data.By leveraging the potentials of the iterative operations,our method enables the reliable estimation of an approximately optimal regularization parameter,all without reliance on any a priori knowledge about the noise characteristics.To demonstrate the reliability,robustness,and accuracy of the method,we perform rigorous numerical assessments using different data models that are infused with noise varying several orders of magnitude.Additionally,practical application of this method is achieved in the experiment on a flexible film flapping in the gusty flow,where the spatiotemporal distribution of the bending force density on the film is calculated by integrating this method with a linear reconstruction.展开更多
Shock tunnels are indispensable facilities for hypersonic aerodynamic experimentation.Within these systems,the diaphragm plays a pivotal role,as its rupture process critically influences shock wave generation quality,...Shock tunnels are indispensable facilities for hypersonic aerodynamic experimentation.Within these systems,the diaphragm plays a pivotal role,as its rupture process critically influences shock wave generation quality,experimental repeatability,and facility reliability.A thorough understanding of diaphragm rupture dynamics is therefore essential for optimizing shock tunnel design,improving experimental accuracy,and ensuring operational safety.To address the complex challenge of fully coupled multiphysics analysis in high-pressure-ratio shock tunnels,this study introduces a high-fidelity,three-dimensional,fully coupled Fluid-Structure Interaction(FSI)simulation framework.This framework seamlessly integrates the Dual Conservation Element and Solution Element(Dual-CESE)method,the Immersed Boundary Method(IBM),and the JohnsonCook(J-C)material constitutive and failure model.The combined approach enables synchronized simulation and analysis of the entire diaphragm rupture sequence—including pre-deformation,crack initiation and propagation,and fully developed petaling deformation—alongside the formation and evolution of the associated supersonic flow field.The simulation results show strong agreement with experimental observations,with the post-rupture geometric morphology accurately replicated and a shock wave velocity deviation of only 2.55%from experimental measurements.The study uncovers the dynamic failure mechanisms,revealing that nonlinear pressure loading initiates cracking within the diaphragm.It further elucidates how the nonlinearly coupled interactions between petaling dynamics and fracture morphology directly impact shock wave formation and evolution.This computational framework provides a novel and robust methodology for advancing shock tunnel design and conducting comprehensive reliability assessments.展开更多
In order to enable wing morphing(e.g.change in camber or folds)without incurring additional weight to the aircraft,lightweight flexible materials such as membrane are needed.However,the research on fluid-structure cou...In order to enable wing morphing(e.g.change in camber or folds)without incurring additional weight to the aircraft,lightweight flexible materials such as membrane are needed.However,the research on fluid-structure coupling of membranes has mainly focused on parachutes in low-speed conditions,while that in supersonic flow conditions is lacking.Here,the degraded shell method is proposed to study membrane deformation by using shell element,which is more effective than using membrane elements directly.A fluid-structure interaction computational framework is proposed,whereby the aerodynamic module is composed of either the piston theory or computational fluid dynamics.A rectangular membrane of length 0.4 m and width 0.6 m is investigated in supersonic conditions.The characteristics of the limit cycle and steady deformation are analyzed,considering the effects of angle of attack and dynamic pressure.It is found that the structural response exhibits significant differences under various angles of attack.Furthermore,initial relaxation of membrane has significant influence on the structural deformation.Finally,the aeroelastic scaling method for membrane structures is derived,providing guidance for the design of wind tunnel models.This study provides a theoretical foundation for the analysis and application of membrane structures under supersonic conditions in future research.展开更多
Host-yeast interactions are fundamental drivers of human microbiome dynamics,spanning a spectrum from mutualistic symbiosis to opportunistic pathogenesis with profound implications for systemic health.This review syst...Host-yeast interactions are fundamental drivers of human microbiome dynamics,spanning a spectrum from mutualistic symbiosis to opportunistic pathogenesis with profound implications for systemic health.This review systematically elucidates the complex molecular mechanisms governing these relationships,with a specific focus on metabolic interdependence and immunomodulation.We analyze how yeast-derived metabolites,particularly short-chain fatty acids(SCFAs),modulate host glucose and lipid homeostasis via signaling pathways such as GPR41/43 and GLP-1 secretion.Furthermore,the review explores the pathophysiological role of fungal dysbiosis in chronic conditions,including obesity,diabetes,and inflammatory bowel disease(IBD),highlighting how a breakdown in host-yeast homeostasis triggers pro-inflammatory cascades.Beyond the fungal-host axis,we introduce the concept of the"mycobiome-virome-bacterial axis,"discussing how commensal yeasts synergize with beneficial bacteria like Bifidobacterium and influence viral infectivity through Interferon-mediated innate immune priming.We critically evaluate how cutting-edge technologies-including transgenic mouse models(specifically Dectin-1^(-/-)and CARD9^(-/-),metabolomics,and single-cell sequencing-have revolutionized our mechanistic understanding of these multi-kingdom dynamics.By integrating current findings,we identify critical knowledge gaps and propose high-resolution research frameworks,such as humanized organ-on-a-chip systems,to simulate intricate host-microbe interactions under physiological flow conditions.This comprehensive synthesis provides a strategic foundation for developing targeted,next-generation microbiome-based interventions to restore host-yeast balance and enhance overall human health.展开更多
The flow control at low Reynolds numbers is one of the most promising technologies in the field of aerodynamics,and it is also an important source of the innovation for novel aircraft.In this study,a new way of nonlin...The flow control at low Reynolds numbers is one of the most promising technologies in the field of aerodynamics,and it is also an important source of the innovation for novel aircraft.In this study,a new way of nonlinear flow control by interaction between two flexible flaps is proposed,and their flow control mechanism is studied employing the self-constructed immersed boundary-lattice Boltzmann-finite element method(IB-LB-FEM).The effects of the difference in material properties and flap length between the two flexible flaps on the nonlinear flow control of the airfoil are discussed.It is suggested that the relationship between the deformation of the two flexible flaps and the evolution of the vortex under the fluid-structure interaction(FSI).It is shown that the upstream flexible flap plays a key role in the flow control of the two flexible flaps.The FSI effect of the upstream flexible flap will change the unsteady flow behind it and affect the deformation of the downstream flexible flap.Two flexible flaps with different material properties and different lengths will change their own FSI characteristics by the induced vortex,effectively suppressing the flow separation on the airfoil’s upper surface.The interaction of two flexible flaps plays an extremely important role in improving the autonomy and adjustability of flow control.The numerical results will provide a theoretical basis and technical guidance for the development and application of a new flap passive control technology.展开更多
We propose a suite of strategies for the parallel solution of fully implicit monolithic fluid-structure interaction(FSI).The solver is based on a modeling approach that uses the velocity and pressure as the primitive ...We propose a suite of strategies for the parallel solution of fully implicit monolithic fluid-structure interaction(FSI).The solver is based on a modeling approach that uses the velocity and pressure as the primitive variables,which offers a bridge between computational fluid dynamics(CFD)and computational structural dynamics.The spatiotemporal discretization leverages the variational multiscale formulation and the generalized-αmethod as a means of providing a robust discrete scheme.In particular,the time integration scheme does not suffer from the overshoot phenomenon and optimally dissipates high-frequency spurious modes in both subproblems of FSI.Based on the chosen fully implicit scheme,we systematically develop a combined suite of nonlinear and linear solver strategies.Invoking a block factorization of the Jacobian matrix,the Newton-Raphson procedure is reduced to solving two smaller linear systems in the multi-corrector stage.The first is of the elliptic type,indicating that the algebraic multigrid method serves as a well-suited option.The second exhibits a two-by-two block structure that is analogous to the system arising in CFD.Inspired by prior studies,the additive Schwarz domain decomposition method and the block-factorization-based preconditioners are invoked to address the linear problem.Since the number of unknowns matches in both subdomains,it is straightforward to balance loads when parallelizing the algorithm for distributed-memory architectures.We use two representative FSI benchmarks to demonstrate the robustness,efficiency,and scalability of the overall FSI solver framework.In particular,it is found that the developed FSI solver is comparable to the CFD solver in several aspects,including fixed-size and isogranular scalability as well as robustness.展开更多
This study reveals the critical role of multiscale interaction within the westerly wind bursts(WWBs)west of the MJO convection in modulating the prediction skill for the November MJO event during the DYNAMO(Dynamics o...This study reveals the critical role of multiscale interaction within the westerly wind bursts(WWBs)west of the MJO convection in modulating the prediction skill for the November MJO event during the DYNAMO(Dynamics of the Madden–Julian Oscillation)field campaign.The characteristics of the MJO convection envelope are obtained by the largescale precipitation tracking method,and a novel metric is introduced to quantify the prediction skill for the MJO convection in the ECMWF reforecast.The ECMWF forecast exhibits approximately 17 days in skillful prediction for the MJO convection—significantly lower than that derived from the global measure.The reforecast ensembles are further classified into high and low skill catalogs based on the mean prediction skill during the observed WWBs period.High-skill ensembles exhibit significantly enhanced low-level westerlies,amplified MJO convection,and reduced spatial separation between the low-level westerlies and MJO convection during the WWBs period,indicating stronger coupling between the large-scale circulation and the convection.Mechanistic analysis reveals that enhanced westerlies in high-skill ensembles can transfer more high-frequency energy to the MJO convection through the flux convergence of interaction energy for MJO convection development,resulting in better prediction skill.展开更多
This paper proposes 2.5-dimensional polymer micromachined insect-mimetic wings based on a fluid-structure interaction(FSI)design concept that enables natural deformations like cambering and pitching under fluid forces...This paper proposes 2.5-dimensional polymer micromachined insect-mimetic wings based on a fluid-structure interaction(FSI)design concept that enables natural deformations like cambering and pitching under fluid forces.Instead of directly employing an analysis for the FSI,an iterative structural Design Window(DW)search is used to reduce the computational cost significantly.A DW search using the iterative method refines the initial design by addressing fabrication challenges and tuning it to meet manufacturability constraints.The successful fabrication and demonstration of the final design solution for a wing demonstrates the effectiveness of the iterative DW search based on the FSI design concept.Furthermore,a pixel model is introduced to convert an unstructured to a structured mesh for the FSI analysis to further reduce the computational cost.The camber and pitching error between the unstructured and structured meshes is minimized to achieve insect-like aerodynamic performance by adjusting the elastic moduli of center and root veins.Finally,an analysis for the FSI is conducted,based on the parameters obtained from the pixel model to evaluate the flight performance on the basis of the lift,camber,and pitching required by an actual insect to maneuver and hover.展开更多
Submarine pipelines are critical infrastructures for offshore energy transport and communications. Understanding their structural response to near-field explosions is crucial for enhancing their blast resistance and o...Submarine pipelines are critical infrastructures for offshore energy transport and communications. Understanding their structural response to near-field explosions is crucial for enhancing their blast resistance and operational safety. This study presents a computational study on the interaction between explosion-induced bubbles and a seabed-mounted pipeline. A recently developed computational framework is employed, which couples a compressible fluid solver with a finite element structural solver via a partitioned procedure. An embedded boundary method and a level-set method are employed to handle the fluid-structure and gas-liquid interfaces. Using this framework, we analyze the flow field evolution, bubble dynamics, and transient pipe deformation. Two distinct response modes are identified: periodic oscillation under low-pressure loading and downward collapse triggered by high-pressure loading and bubble jet impact. Specifically, under high-pressure conditions, the pipe initially deforms inward, generating a localized high-pressure zone within the concave region. During structural rebound, the trapped fluid is expelled upward, giving rise to a bubble jet. Further parametric studies on the pipe's internal pressure, wall thickness, and support angle reveal several key insights. A higher internal pressure delays structural collapse, and a greater pipe thickness results in more uniform implosion morphologies. The support angle strongly influences the collapse dynamics, with the shortest collapse time occurring at 60 °. These findings offer new insights for the protective design of submarine pipelines.展开更多
In ocean engineering, the applications are usually related to a free surface which brings so many interesting physical phenomena （e.g. water waves, impacts, splashing jets, etc.）. To model these complex free surface...In ocean engineering, the applications are usually related to a free surface which brings so many interesting physical phenomena （e.g. water waves, impacts, splashing jets, etc.）. To model these complex free surface flows is a tough and challenging task for most computational fluid dynamics （CFD） solvers which work in the Eulerian framework. As a Lagrangian and meshless method, smoothed particle hydrodynamics （SPH） offers a convenient tracking for different complex boundaries and a straightforward satisfaction for different boundary conditions. Therefore SPH is robust in modeling complex hydrodynamic problems characterized by free surface boundaries, multiphase interfaces or material discontinuities. Along with the rapid development of the SPH theory, related numerical techniques and high-performance computing technologies, SPH has not only attracted much attention in the academic community, but also gradually gained wide applications in industrial circles. This paper is dedicated to a review of the recent developments of SPH method and its typical applications in fluid-structure interactions in ocean engineering. Different numerical techniques for improving numerical accuracy, satisfying different boundary conditions, improving computational efficie- ncy, suppressing pressure fluctuations and preventing the tensile instability, etc., are introduced. In the numerical results, various typical fluid-structure interaction problems or multiphase problems in ocean engineering are described, modeled and validated. The prospective developments of SPH in ocean engineering are also discussed.展开更多
Local Climate Zones(LCZs)provide a standardized framework for analyzing urban thermal environment.Examining the interactive effects of building and green space patterns on land surface temperature(LST)within LCZs is e...Local Climate Zones(LCZs)provide a standardized framework for analyzing urban thermal environment.Examining the interactive effects of building and green space patterns on land surface temperature(LST)within LCZs is essential for uncovering urban cooling mechanisms and developing strategies for heat-mitigation urban design.Therefore,this study employed one-way ANOVA and Duncan's multiple comparison to test compare the significant differences of LST among LCZs 1-6,and applied the XGBoost model to quantify the interactive effects of building and green space indicators on LST,and to identify the threshold ranges of their cooling effects.The results showed that LCZ 2 exhibited the highest LST,while LCZ 4 recorded the lowest.Average building volume(BAV),building coverage ratio(BCR),green cover area(GCA),and the total edge length of green space(GTE)were identified as the key indicators driving the interactive effects on LST.In LCZ 2,when BAV exceeded 1800 m^(3),the interaction of higher GCA and GTE contributed to lower LST.When BCR was less than 0.6 in LCZs 4-5,lower GCA and GTE values enhanced the LST reduction.The results provided a strategic basis for urban thermal environment mitigation and sustainable development under the LCZ framework.展开更多
Using observational and reanalysis datasets,this study explores the mechanisms by which the interactions among multi-timescale flows impacted the onset of rapid intensification(RI)of Typhoon Hato(2017).Hato(2017)forme...Using observational and reanalysis datasets,this study explores the mechanisms by which the interactions among multi-timescale flows impacted the onset of rapid intensification(RI)of Typhoon Hato(2017).Hato(2017)formed within a northwest–southeast-oriented synoptic-scale(with periods<10 days)wave train,concurring with a developing intraseasonal(10–90 days)oscillation and an elongated low-frequency(>90 days)monsoon trough in the western North Pacific.Impacted by continuously increasing vertical wind shear,the TC long maintained a highly asymmetric convective structure.Prior to RI onset,the synoptic-scale circulation and the inner-core asymmetric convection of Hato(2017)greatly strengthened,which are the key factors believed to trigger RI.A multi-timescale eddy kinetic energy budget indicates that the wind convergence associated with the intraseasonal circulation and monsoon trough led to barotropic energy conversion that largely enhanced the synoptic-scale cyclonic circulation.Besides,the pronounced increases in midlevel relative humidity(RH)and surface latent heat flux(LHF)were observed upshear before RI onset,which were primarily driven by the strong intraseasonal and synoptic-scale RH anomalies and the strengthened low-level wind speed,respectively.The increased LHF and midlevel RH,together with the enhanced downshear confluence between synoptic-scale and Intraseasonal Oscillation(ISO)/low-frequency winds,could have helped the intensification of asymmetric convection that supports RI onset.Overall,this study suggests that the interactions across multiple timescales may create favorable dynamic and thermodynamic conditions that promoted RI onset,offering new insights into RI processes for highly asymmetric tropical cyclones like Hato(2017).展开更多
Existing quantitative trait locus(QTL)mapping had low efficiency in identifying small-effect and closely linked QTL-by-environment interactions(QEIs)in recombinant inbred lines(RILs),especially in the era of global cl...Existing quantitative trait locus(QTL)mapping had low efficiency in identifying small-effect and closely linked QTL-by-environment interactions(QEIs)in recombinant inbred lines(RILs),especially in the era of global climate change.To address this challenge,here we integrate the compressed variance component mixed model with our GCIM to propose 3vGCIM for identifying QEIs in RILs,and extend 3vGCIM-random to 3vGCIM-fixed.3vGCIM integrates genome-wide scanning with machine learning,significantly improving power.In the mixed full model,we consider all possible effects and control for all possible polygenic backgrounds.In simulation studies,3vGCIM exhibits higher power(∼92.00%),higher accuracy of the estimates for QTL position(∼1.900 cM2)and effect(∼0.050),and lower false positive rate(∼0.48‰)and false negative rate(<8.10%)in three environments of 300 RILs each than ICIM(47.57%;3.607 cM2,0.583;2.81‰;52.43%)and MCIM(60.30%;5.279 cM2,0.274;2.17‰;39.70%).In the real data analysis of rice yield-related traits in 240 RILs,3vGCIM mines more known genes(57–60)and known gene-by-environment interactions(GEIs)(14–19)and candidate GEIs(21–23)than ICIM(27,2,and 7),and MCIM(21,1,and 3),especially in small-effect and linked QTLs and QEIs.This makes 3vGCIM a powerful and sensitive tool for QTL mapping and molecular QTL mapping.展开更多
A limited understanding of the feeding habits of ecosystem service providers is a notable obstacle to the deployment of natural enemies in pest management.Understanding the dietary diversity of predators can enhance c...A limited understanding of the feeding habits of ecosystem service providers is a notable obstacle to the deployment of natural enemies in pest management.Understanding the dietary diversity of predators can enhance conservation strategies and assess their effects on pest populations.In this study,we used metabarcoding of DNA extracted from the gut contents of an artificially released generalist predator,Eocanthecona furcellata,collected from tobacco cultivation fields in Yunnan Province,China.We aimed to investigate prey composition,selectivity,and efficiency of biological control.Among the individuals of E.furcellata,we detected diverse potential prey,comprising 53 insect species across 28 families and seven orders.Several agricultural pests,including Spodoptera exigua,S.litura,Helicoverpa armigera,and Agrotis segetum,were identified.Diptera are important in the diet of E.furcellata,with 22 species from 14 families accounting for 52.2%of the observed predation events.Eocanthecona furcellata consumed certain beneficial predators present in the tobacco fields,such as carabid beetles,hoverflies,wasps,and lacewings,although the incidence was generally low,except for Syrphidae.Our findings revealed previously unidentified trophic linkages involving E.furcellata with pest species and other biological control agents,as well as highlighting the critical role of neutral insects in shaping the dietary spectrum of E.furcellata in tobacco fields.This study establishes an important foundation for integrating metabarcoding technology into biological control research,particularly for elucidating trophic interactions between natural insect enemies and their prey.展开更多
The antioxidant activity of selenium-containing soybean peptides(SePPs)has been previously demonstrated,despite their limited absorption in the small intestine.This study investigates the antioxidant mechanism of a se...The antioxidant activity of selenium-containing soybean peptides(SePPs)has been previously demonstrated,despite their limited absorption in the small intestine.This study investigates the antioxidant mechanism of a selenium-containing tetrapeptide,Ser-Phe-Gln-SeM(SFQSeM),identified from SePPs,with particular emphasis on its interaction with the intestinal microbiota and its role in modulating host antioxidant defenses.The effects of SFQSeM were evaluated in a D-galactose-induced oxidative stress model and an antibiotictreated mouse model.SFQSeM supplementation significantly reduced the oxidative stress in D-galactosetreated mice.It also promoted the growth of beneficial bacteria and increased the levels of acetate,butyrate and lactate in the intestine(P<0.05).In the antibiotic-treated mouse model,depletion of the intestinal microbiota significantly reduced hepatic glutathione peroxidase(GSH-Px)activity(26.6%)and glutathione peroxidase 1(GPx-1)expression(48.77%)compared to normal mice supplemented with SFQSeM(P<0.05).In contrast to Na_(2)SeO_(3)and selenomethionine,SFQSeM effectively restored the diversity of the intestinal microbiota disrupted by antibiotics.Lactobacillus,Lachnospiraceae_NK4A136_group,and Muribaculaceae were identified as predominant bacteria in the SFQSeM group,and were strongly associated with increased hepatic GSH-Px activity and GPx-1 mRNA expression(P<0.05).In conclusion,intestinal microbiota enhances the antioxidant efficacy of SFQSeM by modulating microbial composition,producing active metabolites,and converting SFQSeM into a bioactive form of selenium.展开更多
Numerical simulations and theoretical models are developed in this paper for the Detonation-Wave/Boundary-Layer Interactions(DWBLIs)under reflections.Transient flow fields demonstrate the highly non-stationarity of th...Numerical simulations and theoretical models are developed in this paper for the Detonation-Wave/Boundary-Layer Interactions(DWBLIs)under reflections.Transient flow fields demonstrate the highly non-stationarity of the DWBLIs when Mach Reflection(MR)occur,and subsequent analyses show that the subsonic region introduced by the boundary layer exacerbates the instability.Further quantitative analyses show that viscosity has little effect on propulsive performance and the separation wave can be considered as an oblique detonation wave.Influence parameters to DWBLIs such as combustion chamber height,incoming Mach number,equivalence ratio,and inlet channel length are categorized and studied.Besides simulations,theoretical analytical modeling is established for Regular Reflection(RR)and MR of DWBLIs.Multiple formulas for the separation zone length are obtained according to the mass conservation under different transformation type between inviscid and viscid reflections.Comparison with the numerical simulations verifies the validity of the model and it can be further generalized to the curved DWBLIs.The developed model makes the theoretical solution process of DWBLIs possible and provides the key foundation for further analysis and solution.展开更多
Understanding the deterioration behaviors and mechanisms of rocks under thermo-hydromechanical(THM)interactions is crucial for mitigating slope instability.In this study,the physicomechanical properties of silty mudst...Understanding the deterioration behaviors and mechanisms of rocks under thermo-hydromechanical(THM)interactions is crucial for mitigating slope instability.In this study,the physicomechanical properties of silty mudstone subjected to THM interactions were investigated by triaxial tests.The underlying micro-mechanisms were revealed using microscopic tests.The triaxial test results indicate that the strength parameters of silty mudstone decrease by 89.50%(deformation modulus),78.15%(peak strength),70.58%(cohesion),and 48.65%(friction angle)under 16 THM cycles,a load of 300 kPa,and alternating between 0℃water immersion and 60℃drying.The SEM test results indicate that the deterioration of silty mudstone strength primarily results from hydrothermal-expansion softening and cracking driven by the TLHM interactions.The specimens manifest shear failure under confining pressure exceeding 140 kPa.Furthermore,a new constitutive model considering hydrothermalexpansion strain and non-linear deformation characteristics was developed.The discrepancy between the experimentally measured peak strength and the damage constitutive model prediction remains below 5%.The proposed model is verified to be in satisfactory agreement with the experimental results.The self-designed THM apparatus overcomes the limitations of traditional investigations,enabling simultaneous consideration of thermal,hydraulic,and mechanical interactions.展开更多
Recycling of waste rubber(WR)is crucial for the sustainable development of the rubber industry.The enhancement of interfacial interactions is the main strategy for waste polymer recycling.However,there is a lack of me...Recycling of waste rubber(WR)is crucial for the sustainable development of the rubber industry.The enhancement of interfacial interactions is the main strategy for waste polymer recycling.However,there is a lack of methods for enhancing the interfacial interactions for WR recycling because WR contains abundant inert C―H bonds.Herein,we designed thioctic acid inverse vulcanization copolymers to endow recycled WR with dynamic disulfide interfacial interactions,significantly improving the mechanical properties of recycled WR.These disulfide interfacial interactions among the recycled WR tend to exchange,which dramatically increases the fractocohesive length and prevents stress concentration near the crack tips.When recycled WR is subjected to external stress,the loads are redistributed across a broad region of adjacent regions instead of being concentrated on a limited length scale,which resists crack propagation.This work effectively recycled WR,providing a strategy for solvent-free reaction-derived inverse vulcanization copolymers to improve the toughness of WR recycling.展开更多
基金supported by the National Natural Science Foundation of China(No.12372233)the Innovation Foundation for Doctor Dissertation of Northwestern Polytechnical University,China(No.25GH01020005)the“111 Project”of China(No.B17037)。
文摘As a multidisciplinary phenomenon,panel aeroelasticity in shock-dominated flow is featured by two primary interactions:Fluid-Structure Interactions(FSIs)and Shock-Boundary Layer Interactions(SBLIs).The former raises structural concerns,and the latter is of aerodynamic interest.Thus,panel aeroelasticity in shock-dominated flow represents a vital topic for the development and optimization of supersonic vehicles and propulsion systems.This review systematically summarizes recent advances in the methodologies applied to capture structural and fluid dynamics,including theoretical models,numerical simulations,and wind tunnel experiments.The application of data-driven modal decomposition,an advanced technique to extract physically crucial features,on the topic is introduced.From the perspective of FSIs,the distinctive aeroelastic behaviors in shock-dominated flow,including hysteresis phenomena and nonlinear responses,are highlighted.From the perspective of SBLIs,the modifications in their spatial and temporal characteristics imposed by the aeroelastic responses are emphasized.Motivated by the interaction between the shock waves and structural response,different strategies have been proposed to implement aeroelastic suppression and shock control,which have the potential to enhance structural safety and aerodynamic performance in the next generation of high-speed flight vehicles.
文摘We present a high performance modularly-built open-source software-OpenIFEM.OpenIFEM is a C++implementation of the modified immersed finite element method(mIFEM)to solve fluid-structure interaction(FSI)problems.This software is modularly built to perform multiple tasks including fluid dynamics(incompressible and slightly compressible fluid models),linear and nonlinear solid mechanics,and fully coupled fluid-structure interactions.Most of open-source software packages are restricted to certain discretization methods;some are under-tested,under-documented,and lack modularity as well as extensibility.OpenIFEM is designed and built to include a set of generic classes for users to adapt so that any fluid and solid solvers can be coupled through the FSI algorithm.In addition,the package utilizes well-developed and tested libraries.It also comes with standard test cases that serve as software and algorithm validation.The software can be built on cross-platform,i.e.,Linux,Windows,and Mac OS,using CMake.Efficient parallelization is also implemented for high-performance computing for large-sized problems.OpenIFEM is documented using Doxygen and publicly available to download on GitHub.It is expected to benefit the future development of FSI algorithms and be applied to a variety of FSI applications.
基金supported by the National Natural Science Foundation of China(Grant Nos.12127802 and 11721202)。
文摘In the experimental investigation of fluid-structure interactions regarding the undulatory motion like flag flapping or fish swimming,solving the force distribution on the flexible body stands as an indispensable endeavor to gain insights into the underlying dynamic mechanisms.However,the solving process entails high-order numerical derivatives of experimental data,which poses a formidable challenge for experimental studies on fluid-structure interactions,given that the measurement noise inherent in experimental data renders the problem ill-posed.The commonly practiced regularization methods for numerical derivatives are feeble to tackle the fourth-order derivative associated with the bending force;those methods,in particular,require predetermined parameters about the unknown noise.We introduce here an empirical regularization method founded upon the kernel-term modification in the frequency domain,notably capable of determining the fourth derivative of experimental data.By leveraging the potentials of the iterative operations,our method enables the reliable estimation of an approximately optimal regularization parameter,all without reliance on any a priori knowledge about the noise characteristics.To demonstrate the reliability,robustness,and accuracy of the method,we perform rigorous numerical assessments using different data models that are infused with noise varying several orders of magnitude.Additionally,practical application of this method is achieved in the experiment on a flexible film flapping in the gusty flow,where the spatiotemporal distribution of the bending force density on the film is calculated by integrating this method with a linear reconstruction.
基金supported by the National Key R&D Program of China(No.2021YFC3100700)。
文摘Shock tunnels are indispensable facilities for hypersonic aerodynamic experimentation.Within these systems,the diaphragm plays a pivotal role,as its rupture process critically influences shock wave generation quality,experimental repeatability,and facility reliability.A thorough understanding of diaphragm rupture dynamics is therefore essential for optimizing shock tunnel design,improving experimental accuracy,and ensuring operational safety.To address the complex challenge of fully coupled multiphysics analysis in high-pressure-ratio shock tunnels,this study introduces a high-fidelity,three-dimensional,fully coupled Fluid-Structure Interaction(FSI)simulation framework.This framework seamlessly integrates the Dual Conservation Element and Solution Element(Dual-CESE)method,the Immersed Boundary Method(IBM),and the JohnsonCook(J-C)material constitutive and failure model.The combined approach enables synchronized simulation and analysis of the entire diaphragm rupture sequence—including pre-deformation,crack initiation and propagation,and fully developed petaling deformation—alongside the formation and evolution of the associated supersonic flow field.The simulation results show strong agreement with experimental observations,with the post-rupture geometric morphology accurately replicated and a shock wave velocity deviation of only 2.55%from experimental measurements.The study uncovers the dynamic failure mechanisms,revealing that nonlinear pressure loading initiates cracking within the diaphragm.It further elucidates how the nonlinearly coupled interactions between petaling dynamics and fracture morphology directly impact shock wave formation and evolution.This computational framework provides a novel and robust methodology for advancing shock tunnel design and conducting comprehensive reliability assessments.
文摘In order to enable wing morphing(e.g.change in camber or folds)without incurring additional weight to the aircraft,lightweight flexible materials such as membrane are needed.However,the research on fluid-structure coupling of membranes has mainly focused on parachutes in low-speed conditions,while that in supersonic flow conditions is lacking.Here,the degraded shell method is proposed to study membrane deformation by using shell element,which is more effective than using membrane elements directly.A fluid-structure interaction computational framework is proposed,whereby the aerodynamic module is composed of either the piston theory or computational fluid dynamics.A rectangular membrane of length 0.4 m and width 0.6 m is investigated in supersonic conditions.The characteristics of the limit cycle and steady deformation are analyzed,considering the effects of angle of attack and dynamic pressure.It is found that the structural response exhibits significant differences under various angles of attack.Furthermore,initial relaxation of membrane has significant influence on the structural deformation.Finally,the aeroelastic scaling method for membrane structures is derived,providing guidance for the design of wind tunnel models.This study provides a theoretical foundation for the analysis and application of membrane structures under supersonic conditions in future research.
基金funded by 2023 Chongqing medical scientific research project(Joint project of Chongqing Health Commission and Science and Technology Bureaugrant no.2023GGXM006)+12 种基金oint project of Chongqing Health Commission and Science and Technology Bureau(Joint Key Laboratory Open Project)(No.2026KFXM051)Natural Science Foundation of Chongqing(No.CSTB2025NSCO-GPX1116)2026 Chongqing Municipal Health Commission Traditional Chinese Medicine Research Project(No.2026WSJK158),Technological Innovation Project of Shapingba District,Chongqing(No.2025016)2024 Scientific research project of Chongqing Medical and Pharmaceutical College(No.ygzrc2024101)Chongqing Municipal Education Commission Youth Project(No.KJQN202402821No.KJQN202502819)2024 Chongqing Medical and Pharmaceutical College Innovation Research Group Project(No.ygz2024401)Science and Health Joint Medical Research Project of Shapingba District,Chongqing(No.2024SQKWLHMS051)2025 Scientific research project of Chongqing Medical and Pharmaceutical College(No.YGZZK2025116)2025 Technological Innovation Project of Shapingba District,Chongqing(No.2025031)Chongqing Municipal Education Commission Youth Project(No.KJQN202402821No.KJQN202302811)Joint project of Chongqing Health Commission and Science and Technology Bureau(No.2024MSXM115)respectively.
文摘Host-yeast interactions are fundamental drivers of human microbiome dynamics,spanning a spectrum from mutualistic symbiosis to opportunistic pathogenesis with profound implications for systemic health.This review systematically elucidates the complex molecular mechanisms governing these relationships,with a specific focus on metabolic interdependence and immunomodulation.We analyze how yeast-derived metabolites,particularly short-chain fatty acids(SCFAs),modulate host glucose and lipid homeostasis via signaling pathways such as GPR41/43 and GLP-1 secretion.Furthermore,the review explores the pathophysiological role of fungal dysbiosis in chronic conditions,including obesity,diabetes,and inflammatory bowel disease(IBD),highlighting how a breakdown in host-yeast homeostasis triggers pro-inflammatory cascades.Beyond the fungal-host axis,we introduce the concept of the"mycobiome-virome-bacterial axis,"discussing how commensal yeasts synergize with beneficial bacteria like Bifidobacterium and influence viral infectivity through Interferon-mediated innate immune priming.We critically evaluate how cutting-edge technologies-including transgenic mouse models(specifically Dectin-1^(-/-)and CARD9^(-/-),metabolomics,and single-cell sequencing-have revolutionized our mechanistic understanding of these multi-kingdom dynamics.By integrating current findings,we identify critical knowledge gaps and propose high-resolution research frameworks,such as humanized organ-on-a-chip systems,to simulate intricate host-microbe interactions under physiological flow conditions.This comprehensive synthesis provides a strategic foundation for developing targeted,next-generation microbiome-based interventions to restore host-yeast balance and enhance overall human health.
基金This work was supported by the National Natural Science Foundation of China(Grant Nos.92371201,52192633,11872293,and 92152301)the Natural Science Basic Research Program of Shaanxi(Grant Nos.2024JC-YBQN-0008,and 2022JC-03)+1 种基金Shaanxi Key Research and Development Program(Grant No.2022ZDLGY02-07)the Joint Natural Science Foundation of China with Guangdong Province for TianHe-II Supercomputer Resources,and the Research Start-up Foundation of Xi’an University of Science and Technology for the High-Level Talent.
文摘The flow control at low Reynolds numbers is one of the most promising technologies in the field of aerodynamics,and it is also an important source of the innovation for novel aircraft.In this study,a new way of nonlinear flow control by interaction between two flexible flaps is proposed,and their flow control mechanism is studied employing the self-constructed immersed boundary-lattice Boltzmann-finite element method(IB-LB-FEM).The effects of the difference in material properties and flap length between the two flexible flaps on the nonlinear flow control of the airfoil are discussed.It is suggested that the relationship between the deformation of the two flexible flaps and the evolution of the vortex under the fluid-structure interaction(FSI).It is shown that the upstream flexible flap plays a key role in the flow control of the two flexible flaps.The FSI effect of the upstream flexible flap will change the unsteady flow behind it and affect the deformation of the downstream flexible flap.Two flexible flaps with different material properties and different lengths will change their own FSI characteristics by the induced vortex,effectively suppressing the flow separation on the airfoil’s upper surface.The interaction of two flexible flaps plays an extremely important role in improving the autonomy and adjustability of flow control.The numerical results will provide a theoretical basis and technical guidance for the development and application of a new flap passive control technology.
基金This work was supported by the National Natural Science Foundation of China(Grant No.12172160)Shenzhen Science and Technology Program(Grant No.JCYJ20220818100600002)+1 种基金South-ern University of Science and Technology(Grant No.Y01326127)the Department of Science and Technology of Guangdong Province(Grant Nos.2020B1212030001 and 2021QN020642).
文摘We propose a suite of strategies for the parallel solution of fully implicit monolithic fluid-structure interaction(FSI).The solver is based on a modeling approach that uses the velocity and pressure as the primitive variables,which offers a bridge between computational fluid dynamics(CFD)and computational structural dynamics.The spatiotemporal discretization leverages the variational multiscale formulation and the generalized-αmethod as a means of providing a robust discrete scheme.In particular,the time integration scheme does not suffer from the overshoot phenomenon and optimally dissipates high-frequency spurious modes in both subproblems of FSI.Based on the chosen fully implicit scheme,we systematically develop a combined suite of nonlinear and linear solver strategies.Invoking a block factorization of the Jacobian matrix,the Newton-Raphson procedure is reduced to solving two smaller linear systems in the multi-corrector stage.The first is of the elliptic type,indicating that the algebraic multigrid method serves as a well-suited option.The second exhibits a two-by-two block structure that is analogous to the system arising in CFD.Inspired by prior studies,the additive Schwarz domain decomposition method and the block-factorization-based preconditioners are invoked to address the linear problem.Since the number of unknowns matches in both subdomains,it is straightforward to balance loads when parallelizing the algorithm for distributed-memory architectures.We use two representative FSI benchmarks to demonstrate the robustness,efficiency,and scalability of the overall FSI solver framework.In particular,it is found that the developed FSI solver is comparable to the CFD solver in several aspects,including fixed-size and isogranular scalability as well as robustness.
基金sponsored by the National Natural Science Foundation of China(Grant Nos.U2442206,42205067,and 41922035)the National Key R&D Program of China(Grant No.2024YFC3013100)the Key Research Program of Frontier Sciences of CAS(Grant No.QYZDB-SSW-DQC017).
文摘This study reveals the critical role of multiscale interaction within the westerly wind bursts(WWBs)west of the MJO convection in modulating the prediction skill for the November MJO event during the DYNAMO(Dynamics of the Madden–Julian Oscillation)field campaign.The characteristics of the MJO convection envelope are obtained by the largescale precipitation tracking method,and a novel metric is introduced to quantify the prediction skill for the MJO convection in the ECMWF reforecast.The ECMWF forecast exhibits approximately 17 days in skillful prediction for the MJO convection—significantly lower than that derived from the global measure.The reforecast ensembles are further classified into high and low skill catalogs based on the mean prediction skill during the observed WWBs period.High-skill ensembles exhibit significantly enhanced low-level westerlies,amplified MJO convection,and reduced spatial separation between the low-level westerlies and MJO convection during the WWBs period,indicating stronger coupling between the large-scale circulation and the convection.Mechanistic analysis reveals that enhanced westerlies in high-skill ensembles can transfer more high-frequency energy to the MJO convection through the flux convergence of interaction energy for MJO convection development,resulting in better prediction skill.
基金supported by the Japan Society for the Promotion of Science KAKENHI under grant number 23H00475.
文摘This paper proposes 2.5-dimensional polymer micromachined insect-mimetic wings based on a fluid-structure interaction(FSI)design concept that enables natural deformations like cambering and pitching under fluid forces.Instead of directly employing an analysis for the FSI,an iterative structural Design Window(DW)search is used to reduce the computational cost significantly.A DW search using the iterative method refines the initial design by addressing fabrication challenges and tuning it to meet manufacturability constraints.The successful fabrication and demonstration of the final design solution for a wing demonstrates the effectiveness of the iterative DW search based on the FSI design concept.Furthermore,a pixel model is introduced to convert an unstructured to a structured mesh for the FSI analysis to further reduce the computational cost.The camber and pitching error between the unstructured and structured meshes is minimized to achieve insect-like aerodynamic performance by adjusting the elastic moduli of center and root veins.Finally,an analysis for the FSI is conducted,based on the parameters obtained from the pixel model to evaluate the flight performance on the basis of the lift,camber,and pitching required by an actual insect to maneuver and hover.
基金supported by the National Key R&D Program of China(Grant No.2024YFC3013200)the Shenzhen Peacock Plan(Grant No.QD2023006C).
文摘Submarine pipelines are critical infrastructures for offshore energy transport and communications. Understanding their structural response to near-field explosions is crucial for enhancing their blast resistance and operational safety. This study presents a computational study on the interaction between explosion-induced bubbles and a seabed-mounted pipeline. A recently developed computational framework is employed, which couples a compressible fluid solver with a finite element structural solver via a partitioned procedure. An embedded boundary method and a level-set method are employed to handle the fluid-structure and gas-liquid interfaces. Using this framework, we analyze the flow field evolution, bubble dynamics, and transient pipe deformation. Two distinct response modes are identified: periodic oscillation under low-pressure loading and downward collapse triggered by high-pressure loading and bubble jet impact. Specifically, under high-pressure conditions, the pipe initially deforms inward, generating a localized high-pressure zone within the concave region. During structural rebound, the trapped fluid is expelled upward, giving rise to a bubble jet. Further parametric studies on the pipe's internal pressure, wall thickness, and support angle reveal several key insights. A higher internal pressure delays structural collapse, and a greater pipe thickness results in more uniform implosion morphologies. The support angle strongly influences the collapse dynamics, with the shortest collapse time occurring at 60 °. These findings offer new insights for the protective design of submarine pipelines.
基金Project supported by the National Natural Science Foun-dation of China(Grant Nos.U1430236,51609049)the China Postdoctoral Science Foundation(Grant No.2015M581432)the China Scholarship Council(CSC,Grant No.201506680004)
文摘In ocean engineering, the applications are usually related to a free surface which brings so many interesting physical phenomena （e.g. water waves, impacts, splashing jets, etc.）. To model these complex free surface flows is a tough and challenging task for most computational fluid dynamics （CFD） solvers which work in the Eulerian framework. As a Lagrangian and meshless method, smoothed particle hydrodynamics （SPH） offers a convenient tracking for different complex boundaries and a straightforward satisfaction for different boundary conditions. Therefore SPH is robust in modeling complex hydrodynamic problems characterized by free surface boundaries, multiphase interfaces or material discontinuities. Along with the rapid development of the SPH theory, related numerical techniques and high-performance computing technologies, SPH has not only attracted much attention in the academic community, but also gradually gained wide applications in industrial circles. This paper is dedicated to a review of the recent developments of SPH method and its typical applications in fluid-structure interactions in ocean engineering. Different numerical techniques for improving numerical accuracy, satisfying different boundary conditions, improving computational efficie- ncy, suppressing pressure fluctuations and preventing the tensile instability, etc., are introduced. In the numerical results, various typical fluid-structure interaction problems or multiphase problems in ocean engineering are described, modeled and validated. The prospective developments of SPH in ocean engineering are also discussed.
基金financial support from the National Natural Science Foundation of China(32271661,32130068).
文摘Local Climate Zones(LCZs)provide a standardized framework for analyzing urban thermal environment.Examining the interactive effects of building and green space patterns on land surface temperature(LST)within LCZs is essential for uncovering urban cooling mechanisms and developing strategies for heat-mitigation urban design.Therefore,this study employed one-way ANOVA and Duncan's multiple comparison to test compare the significant differences of LST among LCZs 1-6,and applied the XGBoost model to quantify the interactive effects of building and green space indicators on LST,and to identify the threshold ranges of their cooling effects.The results showed that LCZ 2 exhibited the highest LST,while LCZ 4 recorded the lowest.Average building volume(BAV),building coverage ratio(BCR),green cover area(GCA),and the total edge length of green space(GTE)were identified as the key indicators driving the interactive effects on LST.In LCZ 2,when BAV exceeded 1800 m^(3),the interaction of higher GCA and GTE contributed to lower LST.When BCR was less than 0.6 in LCZs 4-5,lower GCA and GTE values enhanced the LST reduction.The results provided a strategic basis for urban thermal environment mitigation and sustainable development under the LCZ framework.
基金supported by the National Key Research and Development Program of China(Grant No.2023YFF0807000)supported by the National Natural Science Foundation of China(Grant Nos.42305004,42175073 and 42175013)supported partly by the China Postdoctoral Science Foundation(Grant No.2023M743283).
文摘Using observational and reanalysis datasets,this study explores the mechanisms by which the interactions among multi-timescale flows impacted the onset of rapid intensification(RI)of Typhoon Hato(2017).Hato(2017)formed within a northwest–southeast-oriented synoptic-scale(with periods<10 days)wave train,concurring with a developing intraseasonal(10–90 days)oscillation and an elongated low-frequency(>90 days)monsoon trough in the western North Pacific.Impacted by continuously increasing vertical wind shear,the TC long maintained a highly asymmetric convective structure.Prior to RI onset,the synoptic-scale circulation and the inner-core asymmetric convection of Hato(2017)greatly strengthened,which are the key factors believed to trigger RI.A multi-timescale eddy kinetic energy budget indicates that the wind convergence associated with the intraseasonal circulation and monsoon trough led to barotropic energy conversion that largely enhanced the synoptic-scale cyclonic circulation.Besides,the pronounced increases in midlevel relative humidity(RH)and surface latent heat flux(LHF)were observed upshear before RI onset,which were primarily driven by the strong intraseasonal and synoptic-scale RH anomalies and the strengthened low-level wind speed,respectively.The increased LHF and midlevel RH,together with the enhanced downshear confluence between synoptic-scale and Intraseasonal Oscillation(ISO)/low-frequency winds,could have helped the intensification of asymmetric convection that supports RI onset.Overall,this study suggests that the interactions across multiple timescales may create favorable dynamic and thermodynamic conditions that promoted RI onset,offering new insights into RI processes for highly asymmetric tropical cyclones like Hato(2017).
基金supported by the National Natural Science Foundation of China(32270673 and 32470657).
文摘Existing quantitative trait locus(QTL)mapping had low efficiency in identifying small-effect and closely linked QTL-by-environment interactions(QEIs)in recombinant inbred lines(RILs),especially in the era of global climate change.To address this challenge,here we integrate the compressed variance component mixed model with our GCIM to propose 3vGCIM for identifying QEIs in RILs,and extend 3vGCIM-random to 3vGCIM-fixed.3vGCIM integrates genome-wide scanning with machine learning,significantly improving power.In the mixed full model,we consider all possible effects and control for all possible polygenic backgrounds.In simulation studies,3vGCIM exhibits higher power(∼92.00%),higher accuracy of the estimates for QTL position(∼1.900 cM2)and effect(∼0.050),and lower false positive rate(∼0.48‰)and false negative rate(<8.10%)in three environments of 300 RILs each than ICIM(47.57%;3.607 cM2,0.583;2.81‰;52.43%)and MCIM(60.30%;5.279 cM2,0.274;2.17‰;39.70%).In the real data analysis of rice yield-related traits in 240 RILs,3vGCIM mines more known genes(57–60)and known gene-by-environment interactions(GEIs)(14–19)and candidate GEIs(21–23)than ICIM(27,2,and 7),and MCIM(21,1,and 3),especially in small-effect and linked QTLs and QEIs.This makes 3vGCIM a powerful and sensitive tool for QTL mapping and molecular QTL mapping.
基金supported by the Pests and Diseases Green Prevention and Control Major Special Project(Nos.110202101049[LS-09],110202201018[LS-02])the Key Project of Science and Technology Plan of Yunnan Company of China National Tobacco Corporation(Nos.2022530000241019,2022530000241021)the 2115 Talent Development Program of China Agricultural University.
文摘A limited understanding of the feeding habits of ecosystem service providers is a notable obstacle to the deployment of natural enemies in pest management.Understanding the dietary diversity of predators can enhance conservation strategies and assess their effects on pest populations.In this study,we used metabarcoding of DNA extracted from the gut contents of an artificially released generalist predator,Eocanthecona furcellata,collected from tobacco cultivation fields in Yunnan Province,China.We aimed to investigate prey composition,selectivity,and efficiency of biological control.Among the individuals of E.furcellata,we detected diverse potential prey,comprising 53 insect species across 28 families and seven orders.Several agricultural pests,including Spodoptera exigua,S.litura,Helicoverpa armigera,and Agrotis segetum,were identified.Diptera are important in the diet of E.furcellata,with 22 species from 14 families accounting for 52.2%of the observed predation events.Eocanthecona furcellata consumed certain beneficial predators present in the tobacco fields,such as carabid beetles,hoverflies,wasps,and lacewings,although the incidence was generally low,except for Syrphidae.Our findings revealed previously unidentified trophic linkages involving E.furcellata with pest species and other biological control agents,as well as highlighting the critical role of neutral insects in shaping the dietary spectrum of E.furcellata in tobacco fields.This study establishes an important foundation for integrating metabarcoding technology into biological control research,particularly for elucidating trophic interactions between natural insect enemies and their prey.
基金Financial support from the National Natural Science Foundation of China(32502106)One health Interdisciplinary Research Project,Institute of One Health Science,Ningbo University(NBUOH202502)the Ningbo Top Talent Project(215-432094250).
文摘The antioxidant activity of selenium-containing soybean peptides(SePPs)has been previously demonstrated,despite their limited absorption in the small intestine.This study investigates the antioxidant mechanism of a selenium-containing tetrapeptide,Ser-Phe-Gln-SeM(SFQSeM),identified from SePPs,with particular emphasis on its interaction with the intestinal microbiota and its role in modulating host antioxidant defenses.The effects of SFQSeM were evaluated in a D-galactose-induced oxidative stress model and an antibiotictreated mouse model.SFQSeM supplementation significantly reduced the oxidative stress in D-galactosetreated mice.It also promoted the growth of beneficial bacteria and increased the levels of acetate,butyrate and lactate in the intestine(P<0.05).In the antibiotic-treated mouse model,depletion of the intestinal microbiota significantly reduced hepatic glutathione peroxidase(GSH-Px)activity(26.6%)and glutathione peroxidase 1(GPx-1)expression(48.77%)compared to normal mice supplemented with SFQSeM(P<0.05).In contrast to Na_(2)SeO_(3)and selenomethionine,SFQSeM effectively restored the diversity of the intestinal microbiota disrupted by antibiotics.Lactobacillus,Lachnospiraceae_NK4A136_group,and Muribaculaceae were identified as predominant bacteria in the SFQSeM group,and were strongly associated with increased hepatic GSH-Px activity and GPx-1 mRNA expression(P<0.05).In conclusion,intestinal microbiota enhances the antioxidant efficacy of SFQSeM by modulating microbial composition,producing active metabolites,and converting SFQSeM into a bioactive form of selenium.
基金support of the National Natural Science Foundation of China(Nos.U20A2069,U21B6003,12302389 and 12472337)the Advanced Aero-Power Innovation Workstation,China(No.HKCX2024-01-017)。
文摘Numerical simulations and theoretical models are developed in this paper for the Detonation-Wave/Boundary-Layer Interactions(DWBLIs)under reflections.Transient flow fields demonstrate the highly non-stationarity of the DWBLIs when Mach Reflection(MR)occur,and subsequent analyses show that the subsonic region introduced by the boundary layer exacerbates the instability.Further quantitative analyses show that viscosity has little effect on propulsive performance and the separation wave can be considered as an oblique detonation wave.Influence parameters to DWBLIs such as combustion chamber height,incoming Mach number,equivalence ratio,and inlet channel length are categorized and studied.Besides simulations,theoretical analytical modeling is established for Regular Reflection(RR)and MR of DWBLIs.Multiple formulas for the separation zone length are obtained according to the mass conservation under different transformation type between inviscid and viscid reflections.Comparison with the numerical simulations verifies the validity of the model and it can be further generalized to the curved DWBLIs.The developed model makes the theoretical solution process of DWBLIs possible and provides the key foundation for further analysis and solution.
基金supported by“the National Natural Science Foundation of China(52378440,52078067,52078066,42477143,52408458)the Key Science and Technology Program in the Transportation Industry(2022-MS1-032,2022-MS5-125)+4 种基金the Natural Science Foundation of Hunan Province(2023JJ10045)the Outstanding Innovative Youth Training Program of Changsha City(kq2305023)Scientific Research Foundation of Hunan Provincial Education Department(24B0292)Water Resources Science and Technology Project of Hunan Province(XSKJ2023059-41)the Guangxi Key Research and Development Program(AB23075184)。
文摘Understanding the deterioration behaviors and mechanisms of rocks under thermo-hydromechanical(THM)interactions is crucial for mitigating slope instability.In this study,the physicomechanical properties of silty mudstone subjected to THM interactions were investigated by triaxial tests.The underlying micro-mechanisms were revealed using microscopic tests.The triaxial test results indicate that the strength parameters of silty mudstone decrease by 89.50%(deformation modulus),78.15%(peak strength),70.58%(cohesion),and 48.65%(friction angle)under 16 THM cycles,a load of 300 kPa,and alternating between 0℃water immersion and 60℃drying.The SEM test results indicate that the deterioration of silty mudstone strength primarily results from hydrothermal-expansion softening and cracking driven by the TLHM interactions.The specimens manifest shear failure under confining pressure exceeding 140 kPa.Furthermore,a new constitutive model considering hydrothermalexpansion strain and non-linear deformation characteristics was developed.The discrepancy between the experimentally measured peak strength and the damage constitutive model prediction remains below 5%.The proposed model is verified to be in satisfactory agreement with the experimental results.The self-designed THM apparatus overcomes the limitations of traditional investigations,enabling simultaneous consideration of thermal,hydraulic,and mechanical interactions.
基金financially supported by the National Natural Science Foundation of China(No.52363007)。
文摘Recycling of waste rubber(WR)is crucial for the sustainable development of the rubber industry.The enhancement of interfacial interactions is the main strategy for waste polymer recycling.However,there is a lack of methods for enhancing the interfacial interactions for WR recycling because WR contains abundant inert C―H bonds.Herein,we designed thioctic acid inverse vulcanization copolymers to endow recycled WR with dynamic disulfide interfacial interactions,significantly improving the mechanical properties of recycled WR.These disulfide interfacial interactions among the recycled WR tend to exchange,which dramatically increases the fractocohesive length and prevents stress concentration near the crack tips.When recycled WR is subjected to external stress,the loads are redistributed across a broad region of adjacent regions instead of being concentrated on a limited length scale,which resists crack propagation.This work effectively recycled WR,providing a strategy for solvent-free reaction-derived inverse vulcanization copolymers to improve the toughness of WR recycling.
