SiC/Al-based composite foams were prepared by a two-step foaming method.The influence of the SiC content and its distribution uniformity on the foaming stability,cell structure,and mechanical properties of the aluminu...SiC/Al-based composite foams were prepared by a two-step foaming method.The influence of the SiC content and its distribution uniformity on the foaming stability,cell structure,and mechanical properties of the aluminum foams was investigated.The macro/micro-features of the aluminum foams were characterized and analyzed.Results demonstrate that an appropriate increase in SiC content and the uniform distribution of SiC can improve the foaming stability,optimize the cell diameter and cell wall thickness,ameliorate the cell distribution,and enhance the hardness and compressive strength of the aluminum foams.However,either insufficient or excessive SiC leads to uneven distribution of SiC particles,which is unfavorable to foaming stability and good cell structure formation.With 6wt%SiC,both the foaming stability and cell structure of the aluminum foam reach the optimal state,resulting in the highest compressive strength and optimal energy absorption capacity.展开更多
Non-uniform layers are a common and unavoidable phenomenon in the fabrication of pixel organic light-emitting diodes(OLEDs),particularly in inkjet printing(IJP),which often exhibits pronounced coffee-ring effects.Howe...Non-uniform layers are a common and unavoidable phenomenon in the fabrication of pixel organic light-emitting diodes(OLEDs),particularly in inkjet printing(IJP),which often exhibits pronounced coffee-ring effects.However,accurately simulating these non-uniform features in pixel OLEDs remains a significant challenge for existing methods.In this work,a two-step domain decomposition method was proposed to accurately and efficiently analyze pixel OLEDs with non-uniform layers.In the first step,the whole pixel was divided into several non-overlapping regions according to the dipole radiation range,and the classical dipole radiation model combined with the scattering-matrix method was applied.In the second step,each radiation region was subdivided into uniform and nonuniform parts(quasi-uniform parts),and a modified physical model was introduced to correct the reflection coefficient,transmission coefficient,and phase difference caused by non-uniform layers.The proposed method was verified through both numerical simulations and experiments on a typical IJP OLED.The results showed excellent agreement between the simulated and experimental data,with computational efficiency improved by a factor of 182 compared with COMSOL Multiphysics®.In addition,the analysis of the Purcell effect of a single dipole in a truncated Gaussian microcavity revealed the influence of non-uniformity on the microcavity effect.It explains the physical mechanism of the optical effect caused by non-uniformity,providing a theoretical fundament for non-uniform OLED optimization and manufacturing.This method breaks through the limitations of the traditional uniform model and facilitates the optical simulation and analysis of large-area pixel OLEDs with non-uniform layers.展开更多
We propose a two-step Gauss-Newton method(TS-GNM)for solving nonsmooth equations.At each iteration,the TS-GNM solves both a Gauss-Newton equation and an approximate Gauss-Newton equation.A second-order derivative-free...We propose a two-step Gauss-Newton method(TS-GNM)for solving nonsmooth equations.At each iteration,the TS-GNM solves both a Gauss-Newton equation and an approximate Gauss-Newton equation.A second-order derivative-free line search strategy is designed to ensure the global convergence of TS-GNM.Under the nonsingularity condition and the strong semismoothness of the underlying function,we prove that the TS-GNM converges quadratically.Furthermore,we demonstrate that the TS-GNM achieves a cubic convergence rate when the generalized Jacobian is locally Lipschitz continuous at the solutions.Finally,we pay particular attention to the absolute value equation and present some numerical results.展开更多
Efficient and accurate simulation of unsteady flow presents a significant challenge that needs to be overcome in computational fluid dynamics.Temporal discretization method plays a crucial role in the simulation of un...Efficient and accurate simulation of unsteady flow presents a significant challenge that needs to be overcome in computational fluid dynamics.Temporal discretization method plays a crucial role in the simulation of unsteady flows.To enhance computational efficiency,we propose the Implicit-Explicit Two-Step Runge-Kutta(IMEX-TSRK)time-stepping discretization methods for unsteady flows,and develop a novel adaptive algorithm that correctly partitions spatial regions to apply implicit or explicit methods.The novel adaptive IMEX-TSRK schemes effectively handle the numerical stiffness of the small grid size and improve computational efficiency.Compared to implicit and explicit Runge-Kutta(RK)schemes,the IMEX-TSRK methods achieve the same order of accuracy with fewer first derivative calculations.Numerical case tests demonstrate that the IMEX-TSRK methods maintain numerical stability while enhancing computational efficiency.Specifically,in high Reynolds number flows,the computational efficiency of the IMEX-TSRK methods surpasses that of explicit RK schemes by more than one order of magnitude,and that of implicit RK schemes several times over.展开更多
This study presents an effective hybrid simulation approach for simulating broadband ground motion in complex near-fault locations.The approach utilizes a deterministic approach based on the spectral element method(SE...This study presents an effective hybrid simulation approach for simulating broadband ground motion in complex near-fault locations.The approach utilizes a deterministic approach based on the spectral element method(SEM),which is used to simulate low-frequency ground motion(f1 Hz).A fourth-order Butterworth filter with zero phase shift is employed for time-domain filtering of low-and high-frequency time series at a crossover frequency of 1 Hz,merging the low and high-frequency ground motions into a broadband time series.Taking an Ms 6.8 Luding earthquake,as an example,this hybrid method was used for a rapid and efficient simulation analysis of broadband ground motion in the region.The accuracy and efficiency of this hybrid method were verified through comparisons with actually observed station data and empirical attenuation curves.Deterministic method simulation results revealed the effects of mountainous topography,basin effects,nonlinear effects within the basin’s sedimentary layers,and a coupling interaction between the basin and the mountains.The findings are consistent with similar studies,showing that near-fault sedimentary basins significantly focus and amplify strong ground motion,and the soil’s nonlinear behavior in the basin influences ground motion to varying extents at different distances from the fault.The mountainous topography impacts the basin’s response to ground motion,leading to barrier effects.This research provides a scientific foundation for seismic zoning,urban planning,and seismic design in nearfault mountain basin regions.展开更多
Resistant starch(RS)comprises starch fractions that resist digestion in the small intestine and reach the colon,where they are fermented by the microbiota.Resistant starch harbors functional properties and healthpromo...Resistant starch(RS)comprises starch fractions that resist digestion in the small intestine and reach the colon,where they are fermented by the microbiota.Resistant starch harbors functional properties and healthpromoting ingredients that can regulate blood glucose and lipid levels,prevent cancer,and enhance the quality of life.Consequently,new technologies for the preparation of RS are continually being developed to support its industrial production.This review describes the structural and nutritional properties of RS and examines recent advancements in RS preparation methods.Emphasis is placed on how RS structure influences its properties and the physiological mechanisms in vivo.This review aims to stimulate further research into the preparation methods,functional characteristics,and utilization of RS,thereby supporting ongoing developments in the food industry.展开更多
Traditional targeted analyses often overlook unknown or emerging contaminants,highlighting the significance of nontarget and suspect screening approaches.A novel and high-sensitivity methodology for nontarget analysis...Traditional targeted analyses often overlook unknown or emerging contaminants,highlighting the significance of nontarget and suspect screening approaches.A novel and high-sensitivity methodology for nontarget analysis of organic pollutants in human serum was newly-developed based on gas chromatography coupled with quadrupole time-of-flight high-resolution mass spectrometry.The extraction protocol employing an acetonitrile-ethyl acetate(9:1,V:V)mixture significantly improved the extraction efficiency while minimizing matrix effect.A hybridized analytical strategy integrating nontarget and suspect screening was developed to achieve comprehensive identification and classification of pollutants,employing the National Institute of Standards and Technology(NIST)20 library and Agilent Technologies Personal Compound Database and Library(PCDL).This approach successfully characterized 273 organic contaminants spanning 12 categories,including polycyclic aromatic hydrocarbons(PAHs)and their derivatives,esters,and phenolic compounds in human serum,with a significant increase in detection specificity compared to conventional workflows.The methodology used serum samples of the workers from coking industry,revealing widespread contamination dominated by PAHs and PAH derivatives.Among the target analytes,three were identified solely by NIST and six solely by PCDL,indicating the complementary benefits of combining these different databases.Notably,this work reported the first confirmed detection of 2-naphthalenamine in human serum.This optimized approach demonstrates enhanced sensitivity and reliability in serum analysis,advancing biomonitoring capabilities and providing a deep understanding of human exposure to environmental pollutants.展开更多
This paper presents a highly efficient implicit unified gas-kinetic particle(IUGKP)method for obtaining steady-state solutions of multi-scale phonon transport.The method adapts and reinterprets the integral solution o...This paper presents a highly efficient implicit unified gas-kinetic particle(IUGKP)method for obtaining steady-state solutions of multi-scale phonon transport.The method adapts and reinterprets the integral solution of the Bhatnagar-Gross-Krook(BGK)equation for time-independent solutions.The distribution function at a given point is determined solely by the surrounding equilibrium states,where the corresponding macroscopic quantities are computed through a weighted sum of equilibrium distribution functions from neighboring spatial positions.From a particle perspective,changes in macroscopic quantities within a cell result from particle transport across cell interfaces.These particles are sampled according to the equilibrium state of their original cells,accounting for their mean free path as the traveling distance.The IUGKP method evolves the solution according to the physical relaxation time scale,achieving high efficiency in large Knudsen number regimes.To accelerate convergence for small Knudsen numbers,an inexact Newton iteration method is implemented,incorporating macroscopic equations for convergence acceleration in the near-diffusive limit.The method also addresses spatial-temporal inconsistency caused by relaxation time variations in physical space through the null-collision concept.Numerical tests demonstrate the method’s excellent performance in accelerating multi-scale phonon transport solutions,achieving speedups of one to two orders of magnitude.The IUGKP method proves to be an efficient and accurate computational tool for simulating multiscale non-equilibrium heat transfer,offering significant advantages over traditional methods in both numerical performance and physical applicability.展开更多
Crossflow vortices induced transition is one of the most important instability types in supersonic aircraft boundary layers.While the traditional linear stability theory(LST)-based eN method demonstrates satisfactory ...Crossflow vortices induced transition is one of the most important instability types in supersonic aircraft boundary layers.While the traditional linear stability theory(LST)-based eN method demonstrates satisfactory predictive capabilities for this kind of transition,its practical implementation faces inherent limitations:the requirement of first-and second-order wallnormal derivatives of boundary layer velocityemperature profiles,the need for initial eigenvalue guesses,and the computational burden of solving eigenvalue problems.To address these challenges,this study develops a multi-layer perceptron(MLP)model tailored for linear stability analysis of three-dimensional compressible boundary layers based on the artificially defined quasi-three-dimensional non-similar boundary layer solutions.The boundary layer edge flow parameters and perturbation characteristics are mapped to eigenvalues or local growth rates of the envelop curves through fully connected layers.This architecture eliminates the need for computing wall-normal derivatives of velocityemperature profiles,initial eigenvalue estimation,and direct eigenvalue problem solving.Extensive validation across varying operational conditions and geometries(airfoils and swept wings)demonstrates exceptional agreement between the MLP’s predictions(eigenvalues and disturbance amplification factors)and traditional LST results.Furthermore,the model’s transition prediction capability is rigorously verified using National Aeronautics and Space Administration’s supersonic swept-wing crossflow-dominated transition benchmark,incorporating both stability analysis and flight test data.Results confirm the model is an efficient and reliable computational framework for transition prediction in three-dimensional finite-span wings.展开更多
The long-term responses of offshore wind turbines(OWTs)are critical in the design phase,where precise assessments ensure structural reliability and operational efficiency.The environmental contour method(ECM)enables e...The long-term responses of offshore wind turbines(OWTs)are critical in the design phase,where precise assessments ensure structural reliability and operational efficiency.The environmental contour method(ECM)enables efficient analysis of design responses by focusing on a selected set of critical environmental conditions that predominantly drive long-term extreme responses.Despite its extensive use in offshore engineering,ECM’s application in the structural design and strength assessment of OWTs remains underexplored.This study offers a comprehensive overview of the utilization of ECM in the context of OWT design,incorporating a bibliometric analysis of publications from the Web of Science to identify research trends and key topics.The analysis highlights diverse approaches for estimating long-term extreme responses and constructing environmental contours using statistical distributions.Additionally,the study explores the application of ECM and its modified versions in the design and strength assessment of OWTs.Challenges and opportunities associated with ECM implementation in OWTs are critically analyzed,providing insights into ECM’s potential for enhancing the efficiency and reliability of OWT structural design.展开更多
Advancements in tumor immunotherapy highlight the significant potential of antibody drugs,a key category of biological agents,for treating cancer and autoimmune diseases.This paper begins by defining and classifying k...Advancements in tumor immunotherapy highlight the significant potential of antibody drugs,a key category of biological agents,for treating cancer and autoimmune diseases.This paper begins by defining and classifying key targets in tumor immunity,as well as discussing their structural and functional characteristics.Subsequently,it elaborates on innovative technologies for antibody drug screening,which,when integrated with contemporary molecular biology,biotechnology,and computational biology,have substantially enhanced the efficiency and accuracy of target identification and antibody drug screening processes.Despite the promising prospects of tumor immunotherapy,certain limitations persist in its practical implementation.In conclusion,this paper offers a comprehensive examination of the cutting-edge developments in tumor immunotherapy,focusing on the aspects of tumor immunotherapy itself,critical targets for immunotherapy,and novel technologies and methodologies for antibody screening.This analysis is crucial for advancing the field of tumor immunotherapy and for enhancing both therapeutic efficacy and safety.Furthermore,research and development(R&D)of antibody drugs in other domains,such as autoimmune and inflammatory diseases,can benefit from it.展开更多
Traditional deterministic numerical simulation often has a poor prediction performance for landslide-induced wave run-up(LIWR)hazards,as it neglects the effects of uncertainty.The limitation for efficiently quantifyin...Traditional deterministic numerical simulation often has a poor prediction performance for landslide-induced wave run-up(LIWR)hazards,as it neglects the effects of uncertainty.The limitation for efficiently quantifying the uncertainties in primary parameters remains largely unsolved.In this study,we propose a probabilistic evaluation method,integrating the adaptive Kriging(AK)metamodel method and probability density evolution method(PDEM)based on generalized F-discrepancy.A Taylor expansion-based adaptive design strategy is applied to construct the global AK model over representative points generated by generalized F-discrepancy,thereby approximating the numerical physical response(i.e.,maximum LIWR).Using these approximate responses,the PDEM is used to compute the exceedance probabilities that LIWR heights exceed elements at risk based on a construction of virtual time,and then a probabilistic criterion is introduced to classify hazard zones.The proposed method is demonstrated via two examples:Example I,which possesses risk element(building),and Example Ⅱ with water-level variations.The results indicate that the proposed method has an acceptable performance(showing a 1.7%difference in exceedance probability compared to Monte Carlo simulation with 50,000 samples)with low computation cost(requiring 284 deterministic analyses).For two specific scenarios in this study,the wave induced by the landslide exhibits a solitary-like leading wave.The proposed probabilistic method provides promising prospects for quantifying LIWR uncertainties,and is helpful for direct,efficient,and low-cost quantification assessment of cascading hazards.展开更多
This paper develops a method of characteristics for supersonic viscous flows.The proposed method removes the inviscid and isentropic assumptions of the classical method of characteristics.The characteristic equations ...This paper develops a method of characteristics for supersonic viscous flows.The proposed method removes the inviscid and isentropic assumptions of the classical method of characteristics.The characteristic equations and compatibility equations are derived from the governing equations for compressible viscous flow.By combining the characteristic lines,the triangular interior unit process,quadrilateral interior unit process,and direct sonic point unit process are developed.The unit processes make up the characteristic net.The numerical algorithms consider the path of flow signal propagation.The inviscid terms are solved along characteristic lines,while the viscous terms are corrected through iterative whole-field computations.The proposed method has been applied to supersonic flat-plate boundary layer and verified by the similarity solution.The errors of velocity and temperature profiles are on the order of 0.1%,while the computation efficiency is the same as the classical method of characteristics.The accuracy and efficiency make the proposed method potential to become a basic tool of analysis and design for supersonic viscous flows.展开更多
A high-precision CFD/CSD(Computational Fluid Dynamics/Computational Structural Dynamics)coupling method is developed to study the aeroelastic behavior and design the vibration reduction strategy of NTBT(New Type Blade...A high-precision CFD/CSD(Computational Fluid Dynamics/Computational Structural Dynamics)coupling method is developed to study the aeroelastic behavior and design the vibration reduction strategy of NTBT(New Type Blade-Tip)rotor with TEF(Trailing Edge Flap)technology in forward flight.In the aspect of CSD method,the closed-form dynamical governing equation is modified using Hamilton’s principle to consider the influence of the movable TEF,in which the NTBT geometric nonlinearity is considered through coordinate transformation by virtue of finite element method.In the aspect of CFD method,a moving-embedded grid method for rotor blades is developed to account for the dynamic deflection of TEF,in which the grid deformation is achieved through algebraic transformations,and a high-precision unsteady CFD method with 5th-order TENO(Targeted Essentially Non-Oscillatory)scheme is introduced to effectively simulate the rotor flowfield.Considering the computational efficiency,the loosely-coupling strategy is introduced to build up the CFD/CSD method.The validity of the coupling method is verified by comparing the computed aerodynamic loads,frequency spectrum,and structural loads with the referential or the experimental results of the typical model rotors.Based on that,the frequency,phase,and amplitude-sweeping parametric analyses of TEF are conducted thoroughly to reveal the influence mechanisms on the aeroelastic characteristics of NTBT rotor.Furthermore,an optimal control strategy is proposed to suppress the vibration intensity of hub loads,showing that the active vibration reduction method can effectively suppress the rotor hub vibratory intensity by over 40%in typical forward flight conditions.展开更多
Aerodynamic performances of axial compressors are significantly affected by variation of Reynolds number in aero-engines.In the design and analysis of compressors,previous correction methods for cascades and stages ha...Aerodynamic performances of axial compressors are significantly affected by variation of Reynolds number in aero-engines.In the design and analysis of compressors,previous correction methods for cascades and stages have difficulties in predicting comprehensively Reynolds number effects on airfoils,matching and characteristics curves.This study proposes Re-correction models for loss,deviation angle and endwall blockage based on classical theories and cascade tests,and loss and deviation models show good agreement in test data of NACA65 and C4 cascades.Throughflow method considering Reynolds number effects is developed by integrating the correction models into a verified Streamline Curvature(SLC)tool.A three-stage axial compressor is investigated through SLC and CFD methods from design Reynolds number(Red=2106)to low Re=4104,and the numerical methods are validated with test data of characteristic curves and spanwise distributions at Red.With Re reduction,SLC method with correction models well predicts variation in overall performances compared with CFD calculations and Wassell's model.Streamwise and spanwise matching such as total pressure and loss distributions in SLC predictions are basically consistent with those in CFD results at near-stall points under design and low Reynolds numbers.SLC and CFD methods share similar detections of stall risks in the third stage(Stg3),and their analyses of diffusion processes deviate to some extent due to different predictions in separated endwall flow.The correction models can be adopted to consider Reynolds number effects in through-flow design and analysis of axial compressors.展开更多
To enhance the accuracy of nearshore data products obtained from nadir radar altimeters,we introduce a novel two-step retracking algorithm for reconstructed waveforms.This approach utilizes Empirical Mode Decompositio...To enhance the accuracy of nearshore data products obtained from nadir radar altimeters,we introduce a novel two-step retracking algorithm for reconstructed waveforms.This approach utilizes Empirical Mode Decomposition(EMD)to extract trend information from the trailing edge of the waveform.Reconstructed waveforms are formed by linking the leading and trailing edge trend information.The retracking process consists of two steps:the first step focuses on retracking a segment of the leading edge to obtain 4 crucial a priori parameters.In the second step,retracking incorporates both the leading and trailing edges using the previously acquired a priori information.We tested the algorithm using data from the HY-2B radar altimeter.Results indicate that the proposed two-step retracking algorithm outperforms the Maximum Likelihood Estimation(MLE4)algorithm currently used in the operational processing of the HY-2B radar altimeter,as well as the Adaptive Leading Edge Subwaveform(ALES)algorithm,in terms of significant wave height(SWH)and sea level anomalies(SLA).Specifically,the standard deviation of the difference in SWH is reduced by 14%,and the standard deviation of the difference in SLA is reduced by approximately 18%.The two-step retracking algorithm effectively leverages trailing edge information,reduces the influence of peak noise on the leading edge,and improves both the utilization and accuracy of the waveform retracking.展开更多
In recent years,meshless methods have been increasingly applied to the simulation of various engineering problems due to their inherent advantages over traditional mesh-based approaches,including greater flexibility,i...In recent years,meshless methods have been increasingly applied to the simulation of various engineering problems due to their inherent advantages over traditional mesh-based approaches,including greater flexibility,independence from predefined meshing,simpler adaptive analysis,improved automation,and suitability for complex problems.Several meshless methods have been used for porous media simulation,and are broadly categorized into collocation,global weak form and local weak form methods.In this study,a comprehensive comparison of the applicability of these three categories of meshless methods for simulating coupled flow and transport problems in porous media is presented.The Radial Point Collocation Method(RPCM)(strong form),the Element Free Galerkin Method(EFGM)(global weak form)and the Meshless Local Petrov Galerkin(MLPG)method(local weak form)are implemented and systematically compared.These methods are applied to the analysis of flow in a synthetic regular domain aquifer,flow and non-reactive contaminant transport in a synthetic irregular boundary porous media problem and groundwater flow in a field aquifer located in India.The simulated groundwater heads are compared with analytical solution,observed field data and results obtained from widely used MODFLOW-MT3DMS models.The deviation of the solutions from the analytical solution is in the range of O.67%to O.l6%for the hypothetical case study.For the field-scale case study,mean absolute error of 0.183%,0.18l%and 0.188%are obtained for the RPCM,EFGM and MLPG models,respectively,outperforming MODFLOW,which exhibits a deviation of 0.254%from observed values.Overall,the present study reaffirms the practical applicability of these meshless methods for real-world groundwater problems and provides valuable insights into the utilization of each category of meshless method,with respect to problem type,computational efficiency and accuracy requirements.展开更多
Geological prospecting and the identification of adverse geological features are essential in tunnel construction,providing critical information to ensure safety and guide engineering decisions.As tunnel projects exte...Geological prospecting and the identification of adverse geological features are essential in tunnel construction,providing critical information to ensure safety and guide engineering decisions.As tunnel projects extend into deeper and more mountainous terrains,engineers face increasingly complex geological conditions,including high water pressure,intense geo-stress,elevated geothermal gradients,and active fault zones.These conditions pose substantial risks such as high-pressure water inrush,largescale collapses,and tunnel boring machine(TBM)blockages.Addressing these challenges requires advanced detection technologies capable of long-distance,high-precision,and intelligent assessments of adverse geology.This paper presents a comprehensive review of recent advancements in tunnel geological ahead prospecting methods.It summarizes the fundamental principles,technical maturity,key challenges,development trends,and real-world applications of various detection techniques.Airborne and semi-airborne geophysical methods enable large-scale reconnaissance for initial surveys in complex terrain.Tunnel-and borehole-based approaches offer high-resolution detection during excavation,including seismic ahead prospecting(SAP),TBM rock-breaking source seismic methods,fulltime-domain tunnel induced polarization(TIP),borehole electrical resistivity,and ground penetrating radar(GPR).To address scenarios involving multiple,coexisting adverse geologies,intelligent inversion and geological identification methods have been developed based on multi-source data fusion and artificial intelligence(AI)techniques.Overall,these advances significantly improve detection range,resolution,and geological characterization capabilities.The methods demonstrate strong adaptability to complex environments and provide reliable subsurface information,supporting safer and more efficient tunnel construction.展开更多
Structure-ice interaction problems have attracted increasing attention,yet accurately predicting the loads exerted by sea ice on ship hulls remains a significant challenge.Over the past few decades,various numerical m...Structure-ice interaction problems have attracted increasing attention,yet accurately predicting the loads exerted by sea ice on ship hulls remains a significant challenge.Over the past few decades,various numerical methods have been employed to simulate ice resistance on ships and evaluate their manoeuvrability during ice-structure interaction.Among these approaches,the circumferential crack method has demonstrated both high efficiency and accuracy.This paper provides a detailed introduction to the fundamental theory of this method,including the numerical modeling of different failure modes and the dynamic ice motion responses.Furthermore,it reviews existing studies on predicting ice resistance and assessing the manoeuvrability of icebreakers navigating through ice-covered regions using the circumferential crack method.Several recommendations for future research in this field are also presented.展开更多
Liquid-containing structures,including steam generators,water-cooling systems,in-containment refueling water storage tanks,suppression tanks,and tritiated water storage facilities,are integral components of nuclear re...Liquid-containing structures,including steam generators,water-cooling systems,in-containment refueling water storage tanks,suppression tanks,and tritiated water storage facilities,are integral components of nuclear reactor systems and are crucial for ensuring operational safety and stability.Traditional seismic analysis methods often struggle to accurately predict the dynamic behavior of such structures,particularly under transient events such as earthquakes.This paper presents a comprehensive study that applies the hybrid Eulerian-Lagrangian method to analyze fluid-structure interactions within these structures.The efficacy of this method for capturing the complex dynamics induced by liquid movement is demonstrated through simulations conducted primarily in a vertical storage tank.A comparative analysis with traditional response-spectrum analysis methods underscores the limitations of conventional approaches,particularly in terms of accounting for nonlinear free-surface motions and dynamic velocity distributions.The structural response of the tank containing liquid calculated using the hybrid Eulerian-Lagrangian method is approximately twice that calculated using the response-spectrum method,whereas in the case of a tank without liquid,the response is the same.Additionally,a high dynamic stress distribution exists near the liquid level of the structure.This study addresses the intricate interplay between structural components and fluid dynamics,thereby extrapolating insights from tanks to enhance safety protocols and design considerations for future nuclear devices.展开更多
基金Doctoral Startup Fund(20192066,20212028)Laijin Excellent Doctoral Fund(20202021)+1 种基金Scientific and Technological Innovation of Colleges and Universities in Shanxi Province(2020L0342)Fundamental Research Program of Shanxi Province(202303021222178)。
摘要SiC/Al-based composite foams were prepared by a two-step foaming method.The influence of the SiC content and its distribution uniformity on the foaming stability,cell structure,and mechanical properties of the aluminum foams was investigated.The macro/micro-features of the aluminum foams were characterized and analyzed.Results demonstrate that an appropriate increase in SiC content and the uniform distribution of SiC can improve the foaming stability,optimize the cell diameter and cell wall thickness,ameliorate the cell distribution,and enhance the hardness and compressive strength of the aluminum foams.However,either insufficient or excessive SiC leads to uneven distribution of SiC particles,which is unfavorable to foaming stability and good cell structure formation.With 6wt%SiC,both the foaming stability and cell structure of the aluminum foam reach the optimal state,resulting in the highest compressive strength and optimal energy absorption capacity.
基金funded by the National Key Research and Development Plan of China(2022YFB2803900)the National Natural Science Foundation of China(52130504 and 52450258)+2 种基金Guangdong Basic and Applied Basic Research Foundation(2023A1515030149)Wuhan Science and Technology Major Project(2023010302020031)the Innovation Project of Optics Valley Laboratory,China(OVL2023PY003).
摘要Non-uniform layers are a common and unavoidable phenomenon in the fabrication of pixel organic light-emitting diodes(OLEDs),particularly in inkjet printing(IJP),which often exhibits pronounced coffee-ring effects.However,accurately simulating these non-uniform features in pixel OLEDs remains a significant challenge for existing methods.In this work,a two-step domain decomposition method was proposed to accurately and efficiently analyze pixel OLEDs with non-uniform layers.In the first step,the whole pixel was divided into several non-overlapping regions according to the dipole radiation range,and the classical dipole radiation model combined with the scattering-matrix method was applied.In the second step,each radiation region was subdivided into uniform and nonuniform parts(quasi-uniform parts),and a modified physical model was introduced to correct the reflection coefficient,transmission coefficient,and phase difference caused by non-uniform layers.The proposed method was verified through both numerical simulations and experiments on a typical IJP OLED.The results showed excellent agreement between the simulated and experimental data,with computational efficiency improved by a factor of 182 compared with COMSOL Multiphysics®.In addition,the analysis of the Purcell effect of a single dipole in a truncated Gaussian microcavity revealed the influence of non-uniformity on the microcavity effect.It explains the physical mechanism of the optical effect caused by non-uniformity,providing a theoretical fundament for non-uniform OLED optimization and manufacturing.This method breaks through the limitations of the traditional uniform model and facilitates the optical simulation and analysis of large-area pixel OLEDs with non-uniform layers.
摘要We propose a two-step Gauss-Newton method(TS-GNM)for solving nonsmooth equations.At each iteration,the TS-GNM solves both a Gauss-Newton equation and an approximate Gauss-Newton equation.A second-order derivative-free line search strategy is designed to ensure the global convergence of TS-GNM.Under the nonsingularity condition and the strong semismoothness of the underlying function,we prove that the TS-GNM converges quadratically.Furthermore,we demonstrate that the TS-GNM achieves a cubic convergence rate when the generalized Jacobian is locally Lipschitz continuous at the solutions.Finally,we pay particular attention to the absolute value equation and present some numerical results.
基金supported by the National Natural Science Foundation of China(No.92252201)the Fundamental Research Funds for the Central Universitiesthe Academic Excellence Foundation of Beihang University(BUAA)for PhD Students。
摘要Efficient and accurate simulation of unsteady flow presents a significant challenge that needs to be overcome in computational fluid dynamics.Temporal discretization method plays a crucial role in the simulation of unsteady flows.To enhance computational efficiency,we propose the Implicit-Explicit Two-Step Runge-Kutta(IMEX-TSRK)time-stepping discretization methods for unsteady flows,and develop a novel adaptive algorithm that correctly partitions spatial regions to apply implicit or explicit methods.The novel adaptive IMEX-TSRK schemes effectively handle the numerical stiffness of the small grid size and improve computational efficiency.Compared to implicit and explicit Runge-Kutta(RK)schemes,the IMEX-TSRK methods achieve the same order of accuracy with fewer first derivative calculations.Numerical case tests demonstrate that the IMEX-TSRK methods maintain numerical stability while enhancing computational efficiency.Specifically,in high Reynolds number flows,the computational efficiency of the IMEX-TSRK methods surpasses that of explicit RK schemes by more than one order of magnitude,and that of implicit RK schemes several times over.
基金National Natural Science Foundation of China under Grant Nos.U2139208 and 52278516Key Laboratory of Earthquake Engineering and Engineering Vibration,China Earthquake Administration under Grant No.2024D15Key Laboratory of Soft Soil Characteristic and Engineering Environment,Tianjin Chengjian University under Grant No.2022SCEEKL003。
摘要This study presents an effective hybrid simulation approach for simulating broadband ground motion in complex near-fault locations.The approach utilizes a deterministic approach based on the spectral element method(SEM),which is used to simulate low-frequency ground motion(f1 Hz).A fourth-order Butterworth filter with zero phase shift is employed for time-domain filtering of low-and high-frequency time series at a crossover frequency of 1 Hz,merging the low and high-frequency ground motions into a broadband time series.Taking an Ms 6.8 Luding earthquake,as an example,this hybrid method was used for a rapid and efficient simulation analysis of broadband ground motion in the region.The accuracy and efficiency of this hybrid method were verified through comparisons with actually observed station data and empirical attenuation curves.Deterministic method simulation results revealed the effects of mountainous topography,basin effects,nonlinear effects within the basin’s sedimentary layers,and a coupling interaction between the basin and the mountains.The findings are consistent with similar studies,showing that near-fault sedimentary basins significantly focus and amplify strong ground motion,and the soil’s nonlinear behavior in the basin influences ground motion to varying extents at different distances from the fault.The mountainous topography impacts the basin’s response to ground motion,leading to barrier effects.This research provides a scientific foundation for seismic zoning,urban planning,and seismic design in nearfault mountain basin regions.
基金financially supported by the National Key Research and Development Program of China(2023YFD2100803)the National Natural Science Foundation of China(32372387)+2 种基金the Science and Technology Major Project of Heilongjiang China(2021ZX12B07)Collaborative Innovation Achievement Project of“Double First-class”Disciplines in Heilongjiang Province(LJGXCG202080LJGXCG202083)。
摘要Resistant starch(RS)comprises starch fractions that resist digestion in the small intestine and reach the colon,where they are fermented by the microbiota.Resistant starch harbors functional properties and healthpromoting ingredients that can regulate blood glucose and lipid levels,prevent cancer,and enhance the quality of life.Consequently,new technologies for the preparation of RS are continually being developed to support its industrial production.This review describes the structural and nutritional properties of RS and examines recent advancements in RS preparation methods.Emphasis is placed on how RS structure influences its properties and the physiological mechanisms in vivo.This review aims to stimulate further research into the preparation methods,functional characteristics,and utilization of RS,thereby supporting ongoing developments in the food industry.
基金supported by the National Key Research and Development Project(Nos.2023YFC3905102 and 2024YFC3713201)the National Natural Science Foundation of China(Nos.42207485 and 42407567).
摘要Traditional targeted analyses often overlook unknown or emerging contaminants,highlighting the significance of nontarget and suspect screening approaches.A novel and high-sensitivity methodology for nontarget analysis of organic pollutants in human serum was newly-developed based on gas chromatography coupled with quadrupole time-of-flight high-resolution mass spectrometry.The extraction protocol employing an acetonitrile-ethyl acetate(9:1,V:V)mixture significantly improved the extraction efficiency while minimizing matrix effect.A hybridized analytical strategy integrating nontarget and suspect screening was developed to achieve comprehensive identification and classification of pollutants,employing the National Institute of Standards and Technology(NIST)20 library and Agilent Technologies Personal Compound Database and Library(PCDL).This approach successfully characterized 273 organic contaminants spanning 12 categories,including polycyclic aromatic hydrocarbons(PAHs)and their derivatives,esters,and phenolic compounds in human serum,with a significant increase in detection specificity compared to conventional workflows.The methodology used serum samples of the workers from coking industry,revealing widespread contamination dominated by PAHs and PAH derivatives.Among the target analytes,three were identified solely by NIST and six solely by PCDL,indicating the complementary benefits of combining these different databases.Notably,this work reported the first confirmed detection of 2-naphthalenamine in human serum.This optimized approach demonstrates enhanced sensitivity and reliability in serum analysis,advancing biomonitoring capabilities and providing a deep understanding of human exposure to environmental pollutants.
基金supported by the National Key R&D Program of China(Grant No.2022YFA1004500)the National Science Foundation of China(Grant Nos.12172316,92371107,12302378,92371201,and 52506078)+1 种基金Hong Kong research grant council(Grant Nos.16301222 and 16208324)the Natural Science Basic Research Plan in Shaanxi Province of China(Grant No.2025SYS-SYSZD-070)。
摘要This paper presents a highly efficient implicit unified gas-kinetic particle(IUGKP)method for obtaining steady-state solutions of multi-scale phonon transport.The method adapts and reinterprets the integral solution of the Bhatnagar-Gross-Krook(BGK)equation for time-independent solutions.The distribution function at a given point is determined solely by the surrounding equilibrium states,where the corresponding macroscopic quantities are computed through a weighted sum of equilibrium distribution functions from neighboring spatial positions.From a particle perspective,changes in macroscopic quantities within a cell result from particle transport across cell interfaces.These particles are sampled according to the equilibrium state of their original cells,accounting for their mean free path as the traveling distance.The IUGKP method evolves the solution according to the physical relaxation time scale,achieving high efficiency in large Knudsen number regimes.To accelerate convergence for small Knudsen numbers,an inexact Newton iteration method is implemented,incorporating macroscopic equations for convergence acceleration in the near-diffusive limit.The method also addresses spatial-temporal inconsistency caused by relaxation time variations in physical space through the null-collision concept.Numerical tests demonstrate the method’s excellent performance in accelerating multi-scale phonon transport solutions,achieving speedups of one to two orders of magnitude.The IUGKP method proves to be an efficient and accurate computational tool for simulating multiscale non-equilibrium heat transfer,offering significant advantages over traditional methods in both numerical performance and physical applicability.
基金supported by the National Natural Science Foundation of China(Grant Nos.52372362 and 12102361)the Natural Science Basic Research Program of Shaanxi(Grant No.2025JCJCQN-071)+1 种基金the Zhejiang Provincial Natural Science Foundation of China(Grant No.LR25A020001)the Fundamental Research Funds for the Central Universities(Grant No.G2024KY0615).
摘要Crossflow vortices induced transition is one of the most important instability types in supersonic aircraft boundary layers.While the traditional linear stability theory(LST)-based eN method demonstrates satisfactory predictive capabilities for this kind of transition,its practical implementation faces inherent limitations:the requirement of first-and second-order wallnormal derivatives of boundary layer velocityemperature profiles,the need for initial eigenvalue guesses,and the computational burden of solving eigenvalue problems.To address these challenges,this study develops a multi-layer perceptron(MLP)model tailored for linear stability analysis of three-dimensional compressible boundary layers based on the artificially defined quasi-three-dimensional non-similar boundary layer solutions.The boundary layer edge flow parameters and perturbation characteristics are mapped to eigenvalues or local growth rates of the envelop curves through fully connected layers.This architecture eliminates the need for computing wall-normal derivatives of velocityemperature profiles,initial eigenvalue estimation,and direct eigenvalue problem solving.Extensive validation across varying operational conditions and geometries(airfoils and swept wings)demonstrates exceptional agreement between the MLP’s predictions(eigenvalues and disturbance amplification factors)and traditional LST results.Furthermore,the model’s transition prediction capability is rigorously verified using National Aeronautics and Space Administration’s supersonic swept-wing crossflow-dominated transition benchmark,incorporating both stability analysis and flight test data.Results confirm the model is an efficient and reliable computational framework for transition prediction in three-dimensional finite-span wings.
基金Supported by the China Scholarship Council(CSC)under Grant No.202306440056.
摘要The long-term responses of offshore wind turbines(OWTs)are critical in the design phase,where precise assessments ensure structural reliability and operational efficiency.The environmental contour method(ECM)enables efficient analysis of design responses by focusing on a selected set of critical environmental conditions that predominantly drive long-term extreme responses.Despite its extensive use in offshore engineering,ECM’s application in the structural design and strength assessment of OWTs remains underexplored.This study offers a comprehensive overview of the utilization of ECM in the context of OWT design,incorporating a bibliometric analysis of publications from the Web of Science to identify research trends and key topics.The analysis highlights diverse approaches for estimating long-term extreme responses and constructing environmental contours using statistical distributions.Additionally,the study explores the application of ECM and its modified versions in the design and strength assessment of OWTs.Challenges and opportunities associated with ECM implementation in OWTs are critically analyzed,providing insights into ECM’s potential for enhancing the efficiency and reliability of OWT structural design.
基金supported by the National Natural Science Foundation of China National(Grant Nos:32470999,31970882,81773261,81903140,82041012,82322055,82421005,82473278,92169115)the Shanghai Rising-Star Program(Grant No.:23QA1405800)+3 种基金The Shanghai Outstanding Academic Leader Program(Grant No.:23XD1424800)the Shanghai Key Laboratory of Cell Engineering(Grant No.:14DZ2272300)Yizhang Outstanding Academic Leader Program(Grant No.:JCYZRC-B-008)Cross-disciplinary research fund project of the Ninth People's Hospital affiliated to Shanghai Jiao Tong University School of Medicine(Grant No.:JCJC202410).
摘要Advancements in tumor immunotherapy highlight the significant potential of antibody drugs,a key category of biological agents,for treating cancer and autoimmune diseases.This paper begins by defining and classifying key targets in tumor immunity,as well as discussing their structural and functional characteristics.Subsequently,it elaborates on innovative technologies for antibody drug screening,which,when integrated with contemporary molecular biology,biotechnology,and computational biology,have substantially enhanced the efficiency and accuracy of target identification and antibody drug screening processes.Despite the promising prospects of tumor immunotherapy,certain limitations persist in its practical implementation.In conclusion,this paper offers a comprehensive examination of the cutting-edge developments in tumor immunotherapy,focusing on the aspects of tumor immunotherapy itself,critical targets for immunotherapy,and novel technologies and methodologies for antibody screening.This analysis is crucial for advancing the field of tumor immunotherapy and for enhancing both therapeutic efficacy and safety.Furthermore,research and development(R&D)of antibody drugs in other domains,such as autoimmune and inflammatory diseases,can benefit from it.
基金supported by the Major International(Regional)Joint Research Project of the NSFC(Grant No.42020104006)the National Major ScientificInstruments and Equipment Development Projects of China(Grant No.41827808).
摘要Traditional deterministic numerical simulation often has a poor prediction performance for landslide-induced wave run-up(LIWR)hazards,as it neglects the effects of uncertainty.The limitation for efficiently quantifying the uncertainties in primary parameters remains largely unsolved.In this study,we propose a probabilistic evaluation method,integrating the adaptive Kriging(AK)metamodel method and probability density evolution method(PDEM)based on generalized F-discrepancy.A Taylor expansion-based adaptive design strategy is applied to construct the global AK model over representative points generated by generalized F-discrepancy,thereby approximating the numerical physical response(i.e.,maximum LIWR).Using these approximate responses,the PDEM is used to compute the exceedance probabilities that LIWR heights exceed elements at risk based on a construction of virtual time,and then a probabilistic criterion is introduced to classify hazard zones.The proposed method is demonstrated via two examples:Example I,which possesses risk element(building),and Example Ⅱ with water-level variations.The results indicate that the proposed method has an acceptable performance(showing a 1.7%difference in exceedance probability compared to Monte Carlo simulation with 50,000 samples)with low computation cost(requiring 284 deterministic analyses).For two specific scenarios in this study,the wave induced by the landslide exhibits a solitary-like leading wave.The proposed probabilistic method provides promising prospects for quantifying LIWR uncertainties,and is helpful for direct,efficient,and low-cost quantification assessment of cascading hazards.
基金supported by the Foundation for Innovative Research Groups of the National Natural Science Foundation of China(No.T2221002)the National Natural Science Foundation of China(No.92271203)。
摘要This paper develops a method of characteristics for supersonic viscous flows.The proposed method removes the inviscid and isentropic assumptions of the classical method of characteristics.The characteristic equations and compatibility equations are derived from the governing equations for compressible viscous flow.By combining the characteristic lines,the triangular interior unit process,quadrilateral interior unit process,and direct sonic point unit process are developed.The unit processes make up the characteristic net.The numerical algorithms consider the path of flow signal propagation.The inviscid terms are solved along characteristic lines,while the viscous terms are corrected through iterative whole-field computations.The proposed method has been applied to supersonic flat-plate boundary layer and verified by the similarity solution.The errors of velocity and temperature profiles are on the order of 0.1%,while the computation efficiency is the same as the classical method of characteristics.The accuracy and efficiency make the proposed method potential to become a basic tool of analysis and design for supersonic viscous flows.
基金supported by the National Natural Science Foundation of China(Nos.12102186,12472237)the Young Elite Scientists Sponsorship Program by CAST,China(No.2022QNRC001)+1 种基金the National Key Laboratory Foundation of China(No.61422202201)the Aeronautical Science Foundation of China(No.2024Z010052002)。
摘要A high-precision CFD/CSD(Computational Fluid Dynamics/Computational Structural Dynamics)coupling method is developed to study the aeroelastic behavior and design the vibration reduction strategy of NTBT(New Type Blade-Tip)rotor with TEF(Trailing Edge Flap)technology in forward flight.In the aspect of CSD method,the closed-form dynamical governing equation is modified using Hamilton’s principle to consider the influence of the movable TEF,in which the NTBT geometric nonlinearity is considered through coordinate transformation by virtue of finite element method.In the aspect of CFD method,a moving-embedded grid method for rotor blades is developed to account for the dynamic deflection of TEF,in which the grid deformation is achieved through algebraic transformations,and a high-precision unsteady CFD method with 5th-order TENO(Targeted Essentially Non-Oscillatory)scheme is introduced to effectively simulate the rotor flowfield.Considering the computational efficiency,the loosely-coupling strategy is introduced to build up the CFD/CSD method.The validity of the coupling method is verified by comparing the computed aerodynamic loads,frequency spectrum,and structural loads with the referential or the experimental results of the typical model rotors.Based on that,the frequency,phase,and amplitude-sweeping parametric analyses of TEF are conducted thoroughly to reveal the influence mechanisms on the aeroelastic characteristics of NTBT rotor.Furthermore,an optimal control strategy is proposed to suppress the vibration intensity of hub loads,showing that the active vibration reduction method can effectively suppress the rotor hub vibratory intensity by over 40%in typical forward flight conditions.
基金supported by the National Science and Tech-nology Major Project of China(Nos.2017-II-0007-0021 and J2019-II-0017-0038)。
摘要Aerodynamic performances of axial compressors are significantly affected by variation of Reynolds number in aero-engines.In the design and analysis of compressors,previous correction methods for cascades and stages have difficulties in predicting comprehensively Reynolds number effects on airfoils,matching and characteristics curves.This study proposes Re-correction models for loss,deviation angle and endwall blockage based on classical theories and cascade tests,and loss and deviation models show good agreement in test data of NACA65 and C4 cascades.Throughflow method considering Reynolds number effects is developed by integrating the correction models into a verified Streamline Curvature(SLC)tool.A three-stage axial compressor is investigated through SLC and CFD methods from design Reynolds number(Red=2106)to low Re=4104,and the numerical methods are validated with test data of characteristic curves and spanwise distributions at Red.With Re reduction,SLC method with correction models well predicts variation in overall performances compared with CFD calculations and Wassell's model.Streamwise and spanwise matching such as total pressure and loss distributions in SLC predictions are basically consistent with those in CFD results at near-stall points under design and low Reynolds numbers.SLC and CFD methods share similar detections of stall risks in the third stage(Stg3),and their analyses of diffusion processes deviate to some extent due to different predictions in separated endwall flow.The correction models can be adopted to consider Reynolds number effects in through-flow design and analysis of axial compressors.
基金The National Natural Science Foundation of China under contract No.42192531。
摘要To enhance the accuracy of nearshore data products obtained from nadir radar altimeters,we introduce a novel two-step retracking algorithm for reconstructed waveforms.This approach utilizes Empirical Mode Decomposition(EMD)to extract trend information from the trailing edge of the waveform.Reconstructed waveforms are formed by linking the leading and trailing edge trend information.The retracking process consists of two steps:the first step focuses on retracking a segment of the leading edge to obtain 4 crucial a priori parameters.In the second step,retracking incorporates both the leading and trailing edges using the previously acquired a priori information.We tested the algorithm using data from the HY-2B radar altimeter.Results indicate that the proposed two-step retracking algorithm outperforms the Maximum Likelihood Estimation(MLE4)algorithm currently used in the operational processing of the HY-2B radar altimeter,as well as the Adaptive Leading Edge Subwaveform(ALES)algorithm,in terms of significant wave height(SWH)and sea level anomalies(SLA).Specifically,the standard deviation of the difference in SWH is reduced by 14%,and the standard deviation of the difference in SLA is reduced by approximately 18%.The two-step retracking algorithm effectively leverages trailing edge information,reduces the influence of peak noise on the leading edge,and improves both the utilization and accuracy of the waveform retracking.
摘要In recent years,meshless methods have been increasingly applied to the simulation of various engineering problems due to their inherent advantages over traditional mesh-based approaches,including greater flexibility,independence from predefined meshing,simpler adaptive analysis,improved automation,and suitability for complex problems.Several meshless methods have been used for porous media simulation,and are broadly categorized into collocation,global weak form and local weak form methods.In this study,a comprehensive comparison of the applicability of these three categories of meshless methods for simulating coupled flow and transport problems in porous media is presented.The Radial Point Collocation Method(RPCM)(strong form),the Element Free Galerkin Method(EFGM)(global weak form)and the Meshless Local Petrov Galerkin(MLPG)method(local weak form)are implemented and systematically compared.These methods are applied to the analysis of flow in a synthetic regular domain aquifer,flow and non-reactive contaminant transport in a synthetic irregular boundary porous media problem and groundwater flow in a field aquifer located in India.The simulated groundwater heads are compared with analytical solution,observed field data and results obtained from widely used MODFLOW-MT3DMS models.The deviation of the solutions from the analytical solution is in the range of O.67%to O.l6%for the hypothetical case study.For the field-scale case study,mean absolute error of 0.183%,0.18l%and 0.188%are obtained for the RPCM,EFGM and MLPG models,respectively,outperforming MODFLOW,which exhibits a deviation of 0.254%from observed values.Overall,the present study reaffirms the practical applicability of these meshless methods for real-world groundwater problems and provides valuable insights into the utilization of each category of meshless method,with respect to problem type,computational efficiency and accuracy requirements.
基金supported by the National Natural Science Foundation of China(Grant Nos.52021005,52325904,and 51991391)。
摘要Geological prospecting and the identification of adverse geological features are essential in tunnel construction,providing critical information to ensure safety and guide engineering decisions.As tunnel projects extend into deeper and more mountainous terrains,engineers face increasingly complex geological conditions,including high water pressure,intense geo-stress,elevated geothermal gradients,and active fault zones.These conditions pose substantial risks such as high-pressure water inrush,largescale collapses,and tunnel boring machine(TBM)blockages.Addressing these challenges requires advanced detection technologies capable of long-distance,high-precision,and intelligent assessments of adverse geology.This paper presents a comprehensive review of recent advancements in tunnel geological ahead prospecting methods.It summarizes the fundamental principles,technical maturity,key challenges,development trends,and real-world applications of various detection techniques.Airborne and semi-airborne geophysical methods enable large-scale reconnaissance for initial surveys in complex terrain.Tunnel-and borehole-based approaches offer high-resolution detection during excavation,including seismic ahead prospecting(SAP),TBM rock-breaking source seismic methods,fulltime-domain tunnel induced polarization(TIP),borehole electrical resistivity,and ground penetrating radar(GPR).To address scenarios involving multiple,coexisting adverse geologies,intelligent inversion and geological identification methods have been developed based on multi-source data fusion and artificial intelligence(AI)techniques.Overall,these advances significantly improve detection range,resolution,and geological characterization capabilities.The methods demonstrate strong adaptability to complex environments and provide reliable subsurface information,supporting safer and more efficient tunnel construction.
基金financially supported by the National Natural Science Foundation of China(Grant No.52171259)the National Key Technologies Research and Development Program(Grant No.2022YFE0107000)+1 种基金the High-tech Ship Research Project of the Ministry of Industry and Information Technology(Grant No.[2021]342)the Young Scientists Fund of the National Natural Science Foundation of China(Grant No.52301331).
摘要Structure-ice interaction problems have attracted increasing attention,yet accurately predicting the loads exerted by sea ice on ship hulls remains a significant challenge.Over the past few decades,various numerical methods have been employed to simulate ice resistance on ships and evaluate their manoeuvrability during ice-structure interaction.Among these approaches,the circumferential crack method has demonstrated both high efficiency and accuracy.This paper provides a detailed introduction to the fundamental theory of this method,including the numerical modeling of different failure modes and the dynamic ice motion responses.Furthermore,it reviews existing studies on predicting ice resistance and assessing the manoeuvrability of icebreakers navigating through ice-covered regions using the circumferential crack method.Several recommendations for future research in this field are also presented.
基金supported by the Fusion Vacuum Electrophysics Device Design and Development Project(No.Y15HX11706)。
摘要Liquid-containing structures,including steam generators,water-cooling systems,in-containment refueling water storage tanks,suppression tanks,and tritiated water storage facilities,are integral components of nuclear reactor systems and are crucial for ensuring operational safety and stability.Traditional seismic analysis methods often struggle to accurately predict the dynamic behavior of such structures,particularly under transient events such as earthquakes.This paper presents a comprehensive study that applies the hybrid Eulerian-Lagrangian method to analyze fluid-structure interactions within these structures.The efficacy of this method for capturing the complex dynamics induced by liquid movement is demonstrated through simulations conducted primarily in a vertical storage tank.A comparative analysis with traditional response-spectrum analysis methods underscores the limitations of conventional approaches,particularly in terms of accounting for nonlinear free-surface motions and dynamic velocity distributions.The structural response of the tank containing liquid calculated using the hybrid Eulerian-Lagrangian method is approximately twice that calculated using the response-spectrum method,whereas in the case of a tank without liquid,the response is the same.Additionally,a high dynamic stress distribution exists near the liquid level of the structure.This study addresses the intricate interplay between structural components and fluid dynamics,thereby extrapolating insights from tanks to enhance safety protocols and design considerations for future nuclear devices.