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Prediction method for stationary crossflow instability transition in supersonic boundary layers based on multi-layer perceptron 认领 引用 被引量：2
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作者 Lei Qiao Xi Jiang +5 位作者 Jiakun Fan Yutian Wang Lu Xie Ningjuan Dong Jiakuan Xu Junqiang Bai 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2026年第7期36-51,共16页
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
关键词 Supersonic swept wing Boundary layer transition Crossflow instability Linear stability theory eN method Multi-layer perceptron
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Mechanical metamaterials based on snap-through instability structures:classification,applications,and prospects 认领 引用 被引量：1
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作者 Chengbin Yue Liwu Liu +1 位作者 Yanju Liu Jinsong Leng 《International Journal of Extreme Manufacturing》 SCIE EI CAS CSCD 2026年第1期269-310,共42页
Snap-through instability-based mechanical metamaterials(SIMMs)with bistability,multistability,negative stiffness,or excellent energy absorption and dissipation performance play an important role in various advanced fu... Snap-through instability-based mechanical metamaterials(SIMMs)with bistability,multistability,negative stiffness,or excellent energy absorption and dissipation performance play an important role in various advanced functional applications.They can serve as energy absorbers,energy dampers,or mechanical memory and logic computing devices,while also providing amplified force output and faster response time in flexible robots,or implementing sensing functions combined with piezoelectric or triboelectric electricity.However,thus far,research on SIMMs that have non-fixed boundary constraints,proactive responsiveness,multi-physical field cross-coupling,and deep information processing capabilities is still facing significant challenges,potentially hindering the development and cross-field comprehensive applications of truly intelligent SIMMs.Our objective is to furnish a concise categorization of SIMMs and offer direction for innovative design and functional implementations.We have emphasized that the non-fixed boundary constraint will expand the design possibilities,while the use of stimulus-responsive materials and 4D printing technology will create novel opportunities for the design of SIMMs.These advancements are expected to achieve innovative mechanical properties and functions. 展开更多
关键词 snap-through instability mechanical metamaterials 4D printing variable boundary constraints
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Tracking the complete evolution of electromagnetic instability in an ultra-intense laser-driven plasma 认领 引用
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作者 Moniruzzaman Shaikh Amit D.Lad +4 位作者 Devshree Mandal Kamalesh Jana Deep Sarkar Amita Das G.Ravindra Kumar 《Matter and Radiation at Extremes》 SCIE EI CAS CSCD 2026年第2期44-50,共7页
Plasmas,the most common state of matter in the observable universe,are subject to instabilities of various types:hydrodynamic,magnetohydrodynamic,and electromagnetic.Our limited success in understanding these is due t... Plasmas,the most common state of matter in the observable universe,are subject to instabilities of various types:hydrodynamic,magnetohydrodynamic,and electromagnetic.Our limited success in understanding these is due to the lack of direct experimental information on their origins and evolution.Here,we present direct spatially resolved measurements of the femtosecond evolution of the electromagnetic beam-driven instability that arises from the interaction of forward and return currents in an ultrahigh-intensity laser-produced plasma.We track its evolution from the initial linear stage to the later nonlinear stage by measuring the spatiotemporal evolution of the giant(megagauss)magnetic field created in the interaction process.Our experimental findings and numerical simulations are the first to indicate the observed instability triggered by the emission of electromagnetic radiation,like those known in the context of gravitational interaction,where the emission of gravitational radiation drives specific negative-energy modes in rotating black holes or neutron stars. 展开更多
关键词 electromagnetic instability forward return currents femtosecond evolution plasma magnetic field ultra intense laser hydrodynamic instability magnetohydrodynamic instability
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Influence of key initial parameters on reshocked RichtmyerMeshkov instability 认领 引用
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作者 Jun Wang Yongrui Deng +2 位作者 Yong Zhao Juchun Ding Xisheng Luo 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2026年第4期596-609,共14页
This paper presents an experimental and theoretical study on Richtmyer-Meshkov instability at a light/heavy single-mode gaseous interface under reflected shock wave(reshock)conditions.Particular emphasis is placed on ... This paper presents an experimental and theoretical study on Richtmyer-Meshkov instability at a light/heavy single-mode gaseous interface under reflected shock wave(reshock)conditions.Particular emphasis is placed on the influence of initial conditions(including shock strength,interface density ratio,and amplitude-to-wavelength ratio)on the perturbation growth following reshock.The results reveal that,for all cases,the interface amplitude exhibits a long-term linear growth with time after reshock,followed by a rapid decay in growth rate,highly similar to the perturbation growth behavior after single shock.Higher Mach numbers intensify transverse wave interactions with the interface,significantly affecting the interface morphology.Additionally,the interface is driven closer to the end wall,increasing the frequency of interactions between reverberating waves and the interface.This results in significantly enhanced mixing,as evidenced by the notably larger interface thickness,making the prediction of post-reshock growth rates across varying shock strengths particularly challenging.Interfaces with different density ratios demonstrate similar growth patterns,with the normalized perturbation growth showing near independence from the density ratio.As the amplitude-towavelength ratio increases,distinct transverse shock waves are generated after reshock,which produce high-pressure regions near the interface,causing the bubble head to present a cavity structure.For all cases,the early-stage post-reshock perturbation growth,when appropriately normalized,collapses well at the early stage but diverges at the late stage,especially for cases with varying Mach numbers.The linear superposition model,incorporating a reduction factor,effectively predicts the post-reshock growth rate for cases with different density ratios and initial amplitudes but loses precision for cases with varying shock strengths.Among existing models,the Sadot model(Sadot et al.1998)offers the most reliable predictions for late-stage post-reshock perturbation growth. 展开更多
关键词 Richtmyer-Meshkov instability Reshock Initial conditions
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Variable-angle shear-compression instability in coal:Mechanistic insights and precursor identificationunder hydrochemicalmechanical coupling 认领 引用
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作者 Xiaojun Feng Weitao Yue +2 位作者 Zhiwei Cao Shuaishuai Zhou Enyuan Wang 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2026年第6期4435-4456,共22页
In deep coal mining,mine water containing acidic ions(Cl⁻,SO₄²⁻)often results in the saturation of coal over extended periods,causing physicochemical damage and compromising structural stability.The objective of ... In deep coal mining,mine water containing acidic ions(Cl⁻,SO₄²⁻)often results in the saturation of coal over extended periods,causing physicochemical damage and compromising structural stability.The objective of this study is to elucidate the instability mechanisms of coal subjected to compression-shear fracture in coupled hydrochemical-mechanical environments.Through uniaxial staged loading tests with variable shear angles(α=30°-70°),acoustic emission(AE)monitoring,scanning electron microscopy(SEM)characterization,and discrete element method(DEM),a systematical investigation was conducted to explore the damage evolution of coal saturated in neutral(pH=7)/weakly acidic(pH=5.5)conditions.The results indicate that both shear angles(α)and water chemistry significantly affect the damage evolution of coal.As the shear angle increases,the failure mode shifts from axial splitting to shear dominance,and the b-value decreases from 2.1 to 1.4.Weakly acidic conditions markedly accelerate the damage process,altering the energy release mode from gradual accumulation to sudden,concentrated release.Moment tensor analysis reveals that tensile sources are dominant at low α(45%).At the microscale,coal weakness is primarily induced by the selective dissolution of kaolinite,the formation of interfacial microcracks,and the loss of cementing material under acidic conditions.Based on the critical slowing down(CSD)theory,a precursory warning method focused on variance(S²)and the autocorrelation coefficient(φ)is proposed.These findings provide a theoretical basis for the risk assessment of dynamic disasters in mining and stratified prevention strategies for coal seams with different inclinations. 展开更多
关键词 Dynamic disaster Hydrochemical-mechanical coupling Variable-angle compression-shear Instability mechanism Precursor warning
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Weakly nonlinear Rayleigh–Taylor instability of finite-thickness fluid supported by a semi-infinite fluid 认领 引用
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作者 Hong-Yu Guo Dong-Yu Guo +2 位作者 Ben-Jin Guan Ying-Jun Li Shi-Qi Liu 《Chinese Physics B》 SCIE EI CAS CSCD 2026年第6期800-810,共11页
Rayleigh–Taylor instability(RTI)in multi-interface shells significantly influences shell deformation and material mixing,thereby affecting inertial confinement fusion(ICF)implosion performance.This study investigates... Rayleigh–Taylor instability(RTI)in multi-interface shells significantly influences shell deformation and material mixing,thereby affecting inertial confinement fusion(ICF)implosion performance.This study investigates the weakly nonlinear(WN)RTI in a finite-thickness fluid shell supported by a semi-infinite fluid.We derive the governing equations and third-order WN solutions for RTI growth at both interfaces of the shell.Numerical simulations based on the twodimensional Eulerian framework confirm the validity of the theoretical results in the WN regime.The perturbation growth rate at the lower interface and the interfacial coupling coefficients both exhibit explicit dependence on the Atwood number A and the normalized shell thicknessξ.The WN growth and the deformation of the shell are investigated through the third-order solutions.Comparisons are made with the classical RTI in the WN regime under different initial conditions.Additionally,we analyze the saturation amplitude of the perturbation fundamental mode.It is found that the Atwood number and finite-thickness effects play a pivotal role in the WN evolution of the fluid layer. 展开更多
关键词 Rayleigh–Taylor instability inertial confinement fusion mode-coupling
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Instability characteristics and early warning model of rock direct shear based on acoustic emission 认领 引用
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作者 YE Chun-feng LI Cun-bao +5 位作者 CHEN Heng-jun FENG Ze-chen RAN Qi-can WU Fei HU Jian-jun XIE He-ping 《Journal of Central South University》 SCIE EI CAS CSCD 2026年第6期2682-2702,共21页
Rock shear failure-induced instability,characterized by pronounced nonlinearity and abrupt transitions,frequently leads to severe geological hazards in deep resource extraction and rock engineering structures.This stu... Rock shear failure-induced instability,characterized by pronounced nonlinearity and abrupt transitions,frequently leads to severe geological hazards in deep resource extraction and rock engineering structures.This study uses the critical phase transition theory and catastrophe theory to investigate the acoustic emission(AE)characteristics associated with the transition from stable crack propagation to dynamic shear instability.Real-time AE monitoring was performed during direct shear tests on sandstone to analyze AE responses during the evolution from microcracking to through-going fracture.The results show that during the instability stage,AE energy release,event count,and amplitude increased markedly,whereas fluctuations in AE parameter values decreased,indicating enhanced crack interactions and a sudden shift in failure mode during nonlinear instability.The b-value derived from the maximum likelihood method exhibited a significant decline,reflecting the rapid development of large fractures and the onset of instability.The variance and autocorrelation coefficient of AE energy and count exhibited a sharp increase immediately before instability.As the normal stress increased,the multifractal spectrum width(Δα)of AE energy and count gradually decreased,suggesting that high-energy AE events increasingly dominated destabilization.A novel early warning model based on swallowtail catastrophe theory was developed to overcome the limitations of conventional instability warning methods.This model accurately captures the nonlinear evolution of AE parameters and provides high predictive accuracy and engineering applicability.The proposed model outperforms the superior to existing models that use the b-value,variance,and autocorrelation coefficient as damage precursors,because these models exhibit only slight fluctuations before instability. 展开更多
关键词 acoustic emission(AE) instability critical deceleration multifractal swallowtail catastrophe theory
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What does the surgeon need to know about microsatellite instability in gastric cancers? 认领 引用
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作者 Paulo Pimentel de Assumpção Geraldo Ishak +8 位作者 Paula Baraúna de Assumpção Samir Mansour Moraes Casseb João Felipe Acioli Sérgio Augusto Antunes Ramos Jéssica Manoelli Costa Silva KauêSant'Ana Pereira Guimarães Carolina Baraúna de Assumpção Paulo Kassab Paul Mansfield 《World Journal of Gastrointestinal Oncology》 SCIE 2026年第4期82-88,共7页
Microsatellite instability(MSI)is a molecular subtype of gastric cancer caused by DNA mismatch repair defects,leading to mutations and neoantigen production.This profile influences tumor behavior,prognosis,and respons... Microsatellite instability(MSI)is a molecular subtype of gastric cancer caused by DNA mismatch repair defects,leading to mutations and neoantigen production.This profile influences tumor behavior,prognosis,and response to therapy,making it important for surgical decision-making.This article reviews the mole integrates evidence on pathophysiology,diagnostic strategies,and treatment implications of MSI in gastric cancer,with a focus on surgical oncology.MSI tumors exhibit a high mutational burden due to impaired DNA repair,resulting in increased immunogenicity and potential responsiveness to programmed death 1/programmed death ligand-1(PD-L1)inhibitors.Retrospective studies suggest that patients with MSI-high gastric cancer often have a better prognosis and limited benefit from fluoropyrimidine-based chemotherapy,supporting upfront surgical resection in selected cases.Immunohistochemistry for mismatch repair proteins has become the preferred diagnostic tool,replacing microsatellite testing as the primary screening method.For tumors escaping immune surveillance via PD-L1 expression,targeted immunotherapy offers clinical benefit.Integrating MSI status into the treatment algorithm has shifted gastric cancer management,requiring surgeons to apply molecular oncology principles to optimize outcomes and enhance multidisciplinary coordination. 展开更多
关键词 Gastric cancer Microsatellite instability Mismatch repair Immunotherapy Surgical oncology
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Effects of reflection distance on Richtmyer-Meshkov instability in the reshock process:a discrete Boltzmann study 认领 引用
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作者 Huilin Lai Chuandong Lin +4 位作者 Demei Li Tao Yang Yanbiao Gan Lingyan Lian Aiguo Xu 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2026年第4期464-482,共19页
The Richtmyer-Meshkov(RM)instability occurs when a perturbed interface between two fluids undergoes impulsive acceleration due to a shock wave.In this paper,a numerical investigation of the RM instability during the r... The Richtmyer-Meshkov(RM)instability occurs when a perturbed interface between two fluids undergoes impulsive acceleration due to a shock wave.In this paper,a numerical investigation of the RM instability during the reshock process is conducted using the two-component discrete Boltzmann method.The influence of reflection distance on the RM instability,including both hydrodynamic and thermodynamic non-equilibrium effects,is explored in detail.The interaction time between the reflected shock wave and the material interface varies with different reflection distances.Larger reflection distances lead to a longer evolution time of the material interface before reshock,resulting in more complex effects on the interface deformation,the mixing extent of the fluid system,and non-equilibrium behaviors after reshock.Additionally,while the reflection distance has a minimal impact on mixing entropy before the secondary impact,a significant difference emerges after the secondary impact.This suggests that the secondary impact enhances the evolution of the RM instability.Furthermore,non-equilibrium behaviors or quantities exhibit complex dynamics due to the influence of the transmitted shock wave,transverse waves,rarefaction waves,material interfaces,and dissipation/diffusion processes. 展开更多
关键词 Richtmyer-Meshkov instability Discrete Boltzmann method Non-equilibrium effects Compressible flows Reflection distance
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Revealing the dynamic recrystallization and deformation instability of TiC reinforced AZ61 composites with uniform structure and bimodal grain structure 认领 引用
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作者 Lingling Fan Ying Zeng +7 位作者 Lingbao Ren Yanyan huang Kunyang Fan Zhenyu Zhu Ran Ni Gaofeng Quan Wei Feng Hajo Dieringa 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2026年第2期387-408,共22页
Although microstructural configuration significantly enhances composites’comprehensive mechanical properties,its influence on hot deformation remains unclear.To investigate the effects of microstructural configuratio... Although microstructural configuration significantly enhances composites’comprehensive mechanical properties,its influence on hot deformation remains unclear.To investigate the effects of microstructural configurations on hot workability,dynamic recrystallization(DRX)mechanisms and instability mechanisms,hot compression tests were conducted on two TiC/AZ61 composites(bimodal/uniform structures)with constitutive modeling,processing maps,and microstructure observations.The results show that uniform composite exhibits better hot workability,lower deformation activation energy(Q)and smaller instability regions than bimodal composite.The uniform composite primarily undergoes continuous DRX(CDRX),while the bimodal composite involves both CDRX and discontinuous DRX(DDRX)mechanisms.At low temperatures(T)and high strain rates(˙ε),the uniform composite achieves sufficient DRX,whereas the bimodal composite experiences only partial DRX accompanied by twinning.At high T and low˙ε,the uniform composite is prone to grain boundary sliding(GBS)due to fine grains,causing to micro-voids formation;the bimodal composite undergoes abnormal grain growth(AGG),leading to instability.The favorable hot-processing regions for the bimodal composite are(260-320℃,0.0009-0.03 s-1)and(325-370℃,0.0001-0.0003 s-1),while those for the uniform composite are(260-310℃,0.01-0.1 s-1)and(250-300℃,0.0001-0.0005 s-1).This work offers in-depth insights into DRX and deformation instability in magnesium matrix composites with different initial structures.It provides a guidance for their selection of hot working processes. 展开更多
关键词 Magnesium matrix composite Bimodal structure Hot deformation Dynamic recrystallization Deformation instability
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Evaluating rock instability risk areas in deep mining using microseismic monitoring-based risk fields 认领 引用
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作者 YAN Fang DU Shengnan +3 位作者 DONG Longjun LI Xuan LI Guanguan HE Feifan 《Journal of Mountain Science》 SCIE CSCD 2026年第4期1528-1546,共19页
Microseismic(MS)monitoring is an efficacious technology for the detection and early warning of rock mass instability in deep mining operations.However,existing MS-based early warning methodologies,which primarily rely... Microseismic(MS)monitoring is an efficacious technology for the detection and early warning of rock mass instability in deep mining operations.However,existing MS-based early warning methodologies,which primarily rely on singleparameter analysis or local clustering techniques,typically lack quantitative risk assessment capabilities.Inspired by the concept of a rock instability risk field,this study proposes a spatially continuous methodology for risk evaluation.Specifically,the Empirical Green’s Function(EGF)method is employed to estimate failure probabilities,while a Cloud Model is introduced to quantify potential severity.By integrating these components,a three-dimensional risk field function is formulated,using spatial coordinates as independent variables.Regional risk is then assessed through surface integral formulations,enabling a detailed characterization of its spatial distribution.The proposed methodology was applied to a lead-zinc mine in Northwest China.The calculated regional risk values demonstrate strong spatial consistency with energy density clusters identified using the DBSCAN algorithm.Quantitative comparisons reveal a significant positive correlation between the risk field outputs and independent MS event clusters,confirming the method’s efficacy in capturing the spatiotemporal concentration of instability potential.These findings indicate that representing rock instability risk as a continuous field enhances the regional interpretability of MS data and offers a quantitative foundation for dynamic hazard zonation in deep underground excavations. 展开更多
关键词 Microseismic monitoring Deep mining Rock instability Risk field Risk assessment Surface integral
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Restraining plastic instability of intercritically annealed 7Mn medium manganese steel via pre-water quenching 认领 引用
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作者 Mei Zhang Wen-Hao Li +6 位作者 Wei-Kun Wang Qing Xu Jie Zhang Qiong-Ying Cen Yang Wang Xiao-Fei Guo Han Dong 《Journal of Iron and Steel Research International》 SCIE EI CSCD 2026年第2期193-208,共16页
The plastic instability and maintaining excellent mechanical properties of 7Mn medium manganese steel(MMnS)were restrained via the inclusion of a pre-water quenching(WQ)step before the traditional intercritical anneal... The plastic instability and maintaining excellent mechanical properties of 7Mn medium manganese steel(MMnS)were restrained via the inclusion of a pre-water quenching(WQ)step before the traditional intercritical annealing(IA)treatment(at 630℃ for 1,2,4 and 8 h).The cold-rolling alloy was austenitized at 850℃ for 0.5 h and then water-quenched to room temperature in advance to adjust the original and final microstructures.The pre-WQ step caused the final ferrite and austenite dual-phase morphology to change from nano-equiaxed to nano-lamellar+equiaxed.The sample after traditional IA at 630℃ for 1 h exhibited excellent comprehensive mechanical properties,with a product of ultimate tensile strength and total elongation(UTS·TEL)of 48.9 GPa%;however,the yield point elongation(YPE)indicating typical plastic instability was as high as 17%.In contrast,the sample after WQ+IA at 630℃ for 4 h showed a similar UTS·TEL of 42.2 GPa%,but the plastic instability phenomena,including the formation of Lüders bands(related to YPE)and Portevin–Le Chatelier bands,were greatly restrained.This was due to the low degree of recrystallization,mixed morphology of the final microstructure,high original dislocation density in ferrite,and fine grain size resulting from pre-WQ.Additionally,the substitution of TEL with positive plasticity(PP=TEL−YPE)allowed a more accurate assessment of the comprehensive properties of MMnS.The as-prepared Lüders-band-free MMnS,with outstanding comprehensive mechanical properties,is of great significance owing to its extensive application potential in the automotive industry. 展开更多
关键词 Medium manganese steel Pre-water quenching Dual-phase morphology Plastic instability High original dislocation density
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Pulsed octupole magnet for beam instability mitigation in rapid cycling synchrotron 认领 引用
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作者 Liang‑Sheng Huang Shou‑Yan Xu +7 位作者 Yun‑Tao Liu Yi‑Qin Liu Jian‑Liang Chen Chang‑Dong Deng Ming‑Yang Huang Li Rao Han‑Yang Liu Xin Qi 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2026年第1期107-118,共12页
The rapid cycling synchrotron(RCS)at the China spallation neutron source operates as a high-intensity proton accelerator.The coupled bunch instability was observed during RCS beam commissioning,which significantly lim... The rapid cycling synchrotron(RCS)at the China spallation neutron source operates as a high-intensity proton accelerator.The coupled bunch instability was observed during RCS beam commissioning,which significantly limited the beam power.To investigate the dynamics of instability under an increased beam power,a pulsed octupole magnet with a gradient of 900 T/m3 was developed.The magnet system integrated an octupole magnet with a pulsed power supply.The field was carefully measured to examine the performance before its installation into the tunnel.After the installation of the magnets,beam measurements were performed to confirm the effectiveness of the instability mitigation on an actual proton beam.The measurement results show that the instability can be suppressed using the pulsed octupole magnet,particularly at the highenergy stage in an acceleration cycle,meeting the requirements for stable operation of the accelerator.Additionally,when the instability is completely suppressed through chromaticity optimization,octupole magnets can significantly enhance the RCS transmission efficiency,which is crucial for controlling beam loss.The pulsed octupole magnet offers significant progress in beam stability in the RCS,providing valuable experience for further beam power enhancement. 展开更多
关键词 China spallation neutron source Rapid cycling synchrotron Coupled bunch instability Octupole magnet
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Rainfall-induced instability mechanisms and slope angle optimization in open pit mines 认领 引用
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作者 YANG Xiaojie LIU Keyuan +2 位作者 LEI Xiaotian TAN Xingxing LIU Xingyu 《Journal of Mountain Science》 SCIE CSCD 2026年第6期2927-2947,共21页
Unreasonable design of the slope angle of the open pit mine is one of the main causes of slope instability,and this issue is particularly prominent under rainfall infiltration conditions.Therefore,designing a scientif... Unreasonable design of the slope angle of the open pit mine is one of the main causes of slope instability,and this issue is particularly prominent under rainfall infiltration conditions.Therefore,designing a scientific,economical,and reasonable slope angle based on the failure mechanism of open pit mine slopes is of great significance for the mining safety and long-term stability of open pit mine slopes.This paper aims to propose an MSARMA slope angle optimization method with simple calculation and wide applicability and verify its rationality by utilizing the characteristics of constant-resistance large-deformation(CRLD)anchor cables that can monitor slope stability.Relevant research was carried out by taking four hazardous profiles of the Antaibao Open-pit Coal Mine in China as examples.The results show that slope instability under rainfall infiltration conditions can be divided into four stages through numerical simulation analysis combined with the actual on-site failure process:surface scouring,surface settlement,crack propagation,and shear slip.The slope angles were optimized for the four hazardous profiles with historical landslide occurrences,and the optimization results were verified using field monitoring data.When the slope angles of A-A′,B-B′,C-C′and D-D′dangerous sections are 34°,32°,33°and 33°respectively,the safety,stability,and economic rationality of the slope can be guaranteed.This study provides a theoretical basis and practical reference for slope angle optimization under similar engineering geological conditions. 展开更多
关键词 Slope instability mechanism Numerical simulation Slope angle optimization Msarma Open pit mine
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Study on instability evolution mechanism of intermediate bridge retaining slope 认领 引用
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作者 Dong Wang Zuchao Liang +6 位作者 Guanghe Li Zihuan Hu Pengfei Cui Jiankang Feng Pengyu Wang Kun Fang Pengjiao Zhang 《International Journal of Coal Science & Technology》 SCIE EI CAS CSCD 2026年第2期91-121,共31页
Excavation is one of the key factors inducing slope instability in open-pit mines,particularly for intermediate bridge-supported slopes subjected to dual excavation disturbances.Improper handling of such conditions ma... Excavation is one of the key factors inducing slope instability in open-pit mines,particularly for intermediate bridge-supported slopes subjected to dual excavation disturbances.Improper handling of such conditions may lead to large-scale landslides.Therefore,it is essential to investigate the instability evolution mechanism of intermediate bridge-supported slopes under dual excavation conditions.In this study,the southern slope of the Zhahanaoer Open-Pit Coal Mine was selected as the research area,and a physical model of the intermediate bridge-supported slope capable of simulating eight excavation stages was constructed.Field monitoring was conducted using non-reflective cameras,earth pressure sensors,and a distributed optical fiber system to analyze the evolution characteristics of cracks,surface deformation,internal strain,and stress in the slope model during excavation.The reliability of the physical model tests was validated by comparing the results with field landslide cases using numerical simulation techniques.The results indicate that internal strain precedes surface displacement in predicting or inferring slope instability and can serve as an early warning indicator for landslides.The failure process of the intermediate bridge-supported slope model can be divided into five stages:crack initiation,crack propagation,deformation onset,crack penetration,and local and global instability on both sides of the intermediate bridge.Furthermore,excavation significantly increases the height of the arched failure surface on both sides compared to its span,and the increase in the height-to-span ratio is a critical characteristic of failure surface evolution.These findings provide a prerequisite for related slope stability analyses,intermediate bridge demolition engineering design,and slope remediation projects. 展开更多
关键词 Slope physical model Intermediate bridge-supported slope Deformation and failure characteristics Instability mechanism Double rock arching effect
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Underlying cause of diabetic retinopathy:Metabolic instability 认领 引用
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作者 Francesco Cappellani Matteo Capobianco +9 位作者 Francesco Leonforte Alessandro Avitabile Federico Visalli Marieme Khouyyi Rosa Giglio Leandro Inferrera Daniele Tognetto Fabiana D'Esposito Caterina Gagliano Marco Zeppieri 《World Journal of Clinical Cases》 2026年第12期1-11,共11页
Although diabetic retinopathy is still a major contributor to avoidable visual impairment,its pathophysiology is frequently only considered in relation to chronic hyperglycemia.This rigid viewpoint is challenged by ne... Although diabetic retinopathy is still a major contributor to avoidable visual impairment,its pathophysiology is frequently only considered in relation to chronic hyperglycemia.This rigid viewpoint is challenged by new data that highlight the pathogenic importance of transient metabolic instability.Retinal endothelial cells,pericyte viability,and neuroglial equilibrium appear to be independently influenced by rapid glucose fluctuations,variability in fasting glucose,and transient metabolic stress,which accelerates microvascular and neurodegenerative injury.These results suggest that dynamic metabolic instability is associated with increased retinal vulnerability and may contribute to microvascular and neurodegenerative injury.Despite growing interest,the lack of validated thresholds for harmful glycemic volatility,inconsistent variability metrics,and diverse study methodologies limits clinical translation.To identify early neurovascular dysfunction,future research should integrate continuous glucose monitoring parameters with retinal imaging biomarkers.Adopting a dynamic metabolic framework may improve risk assessment,enable tailored screening plans,and ultimately advance the prevention and treatment of diabetic retinopathy. 展开更多
关键词 Metabolic instability Diabetic retinopathy Glycemic variability Metabolic memory Continuous glucose monitoring Oxidative stress Neurovascular unit
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On the shear instability over the swell wave 认领 引用
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作者 Zhongshui Zou Dongxiao Wang Jinbao Song 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2026年第4期60-71,共12页
Under the assumption of the constant flux layer,Monin-Obukhov Similarity Theory(MOST)is widely employed to relate wind stress to mean wind profiles.However,by summarizing several observations,this paper finds that the... Under the assumption of the constant flux layer,Monin-Obukhov Similarity Theory(MOST)is widely employed to relate wind stress to mean wind profiles.However,by summarizing several observations,this paper finds that the behavior of wind profiles close to the surface differs from that predicted by MOST,which is larger than that estimated by MOST under wind sea conditions and smaller than that for swell cases.The wave coherent stress computed from the widely used traditional vertical decay function is almost one order of magnitude smaller than that derived from observations.A coupled model based on the shear instability with an“arbitrary”wind profile is used to investigate the above phenomena.The result shows that the deviation of the wind profile from MOST is due to the wave coherent stress that considers parts of the total stress.Thus,accurate determination of the wave effect height or the height to which wave coherent stress can extend is very important in air-sea interactions.Our model suggests that only those wave modes that have phase speeds greater than U(z)can extend their stress higher than z,here U(z)is the wind speed at height z.Compared with the traditional vertical decay function,the results of this study are in good agreement with the observed wave coherent stress. 展开更多
关键词 wave coherent stress wind profiles shear instability swell wave several observationsthis Monin Obukhov similarity theory vertical decay function
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Modeling and Analysis on Flow Instability of Helical Coiled Tube Steam Generator of Liquid Metal Fast Reactor under Coupled Heat Transfer Conditions 认领 引用
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作者 Jialun Liu Yuchang Lu +3 位作者 Jianjun Lin Shebing Li Ruixia Gao Zhao Li 《Frontiers in Heat and Mass Transfer》 EI CAS 2026年第2期178-195,共18页
A steady thermo-hydraulic model of the helical tube steam generator was first constructed to study the coupled heat transfer process between the primary and secondary sides based on a discrete modeling method,and obta... A steady thermo-hydraulic model of the helical tube steam generator was first constructed to study the coupled heat transfer process between the primary and secondary sides based on a discrete modeling method,and obtain the heat flux density distribution along the steam generator.Then,taking the obtained coupled heat flux density distribution as the thermal boundary condition input,considering the dynamic variation of physical properties on the secondary side,a dynamic model based on the time-domain method suitable for two-phase flow instability among parallel multiple channels of the steam generator was constructed.Finally,taking the lead-bismuth fast reactor as an example,flow instability of the steam generator was analyzed under an inlet lead-bismuth temperature of 320℃~480℃ and an inlet water temperature of 160℃~240℃.It was found that flow instability is less likely to occur under coupled heat conditions,compared with that under uniform or linear distribution.Flow excursion is prone to occur under low inlet temperature of the primary or secondary side.As the inlet lead bismuth temperature increases from 320℃ to 480℃,average heat flux significantly increases by 2.5 times,and the non-uniformity of heat flux distribution increases of 49%.Meanwhile,the density wave oscillation amplitude gradually increases,and system stability weakens. 展开更多
关键词 Liquid metal fast reactor helical coiled tube steam generator two-phase flow instability discrete method coupled heat transfer between primary side and second side
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Dynamic instability and catastrophe mechanisms of surrounding rock with rigid-flexible coupling supporting structure under bidirectional impact loading 认领 引用
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作者 YANG Rong-zhou XU Ying +2 位作者 ZHANG Quan HE Man-chao YU Mei-lu 《Journal of Central South University》 SCIE EI CAS CSCD 2026年第1期224-256,共33页
Aiming at the problem of dynamic instability of hard-brittle jointed rock surrounding in deep tunneloadway engineering,combining with the support concepts of"coupling rigidity with flexibility"and"overc... Aiming at the problem of dynamic instability of hard-brittle jointed rock surrounding in deep tunneloadway engineering,combining with the support concepts of"coupling rigidity with flexibility"and"overcoming rigidity by flexibility",the prevention and control method with"rigid-flexible coupling(R-F-C)"was put forward.Through numerical simulation calculation,the impact damage process,acoustic emission(AE)evolution characteristics,and element stress/displacement evolution characteristics of unsupported surrounding rock structure model,rigid supporting surrounding rock structure model,and"R-F-C"supporting surrounding rock structure model under horizontal bidirectional impact loading were compared and analyzed.Based on the theory of stress wave propagation,the dynamic instability catastrophe mechanism of three kinds of supporting structure models induced by horizontal bidirectional impact loading was revealed.Based on the Mohr-Coulomb strength theory,the stress discrimination methods of dynamic catastrophe of surrounding rock induced by horizontal bidirectional impact loading under three kinds of supporting structures were proposed.Combined with the above numerical simulation study,the explosion impact physical and mechanical test of"R-F-C"surrounding rock supporting plate structure was further designed and carried out.Finally,combined with the"conceptual model of ball-cliff potential energy instability",the energy driving theory and energy transformation mechanism of impact-induced rockburst under three kinds of supporting structures were discussed deeply.The research results provided a scientific basis for further promoting the effective application of"R-F-C"supporting structure in the prevention and control of dynamic instability of deep tunneloadway surrounding rock. 展开更多
关键词 jointed surrounding rock rigid-flexible coupling(R-F-C)supporting structure stress wave propagation acoustic emission(AE) damage evolution impact instability catastrophe mechanism
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Tropical instability waves and their relationships with large-scale oceanic thermal conditions,revealed in ROMS-based hybrid coupled model of the tropical Pacific 认领 引用 被引量：1
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作者 Yinnan LI Yang YU +2 位作者 Chuan GAO Hongna WANG Rong-Hua ZHANG 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2026年第2期461-476,共16页
This study evaluates the performance of a Regional Ocean Modeling System-based Hybrid Coupled Model(HCMROMS)in simulating tropical instability waves(TIWs),their modulation by the El Niño-Southern Oscillation(E... This study evaluates the performance of a Regional Ocean Modeling System-based Hybrid Coupled Model(HCMROMS)in simulating tropical instability waves(TIWs),their modulation by the El Niño-Southern Oscillation(ENSO)in the tropical Pacific Ocean,and their impacts on the mean state thermal conditions of the ocean.HCMROMSintegrates the Regional Ocean Modeling System(ROMS)with a statistical atmospheric model for surface wind stress anomalies based on Singular Value Decomposition(SVD),aiming to accurately represent air-sea coupling interactions and TIWs-related ocean mesoscale processes.The model successfully reproduces the climatological state and seasonal variability of sea surface temperature(SST)in the tropical Pacific.In simulating ENSO,HCMROMScaptures the quasi-three year oscillation characteristic of ENSO.Regarding TIWs,the model accurately reproduces their main features and periods.Additionally,HCMROMSshows a significantly negative correlation between the strength of TIWs and the Niño 3.4 index,being consistent with empirical analyses from observations.The model’s ability to simulate the interaction between TIWs and ENSO allows us to analyze the TIWs related energy and heat budgets.The model’s energy budget reveals that the strength of TIWs is strongly modulated by ENSO phases.The study also examines the feedback effects of TIWs on the mean state through a heat budget analysis.These results indicate that TIWs play a crucial role in the climatological heat balance,with the amplitude being comparable to sea surface heat flux.These findings underscore the importance of accurately simulating TIWs to better represent and understand their role in the tropical Pacific climate system.Overall,HCMROMSdemonstrated robust performance in representing both ENSO and TIWs,offering a reliable tool for future studies on their interactions and the broader dynamics of the tropical Pacific Ocean.The model’s precise representations of TIWs and their relationship with ENSO highlight its potential in advancing our understanding of ocean-atmosphere interactions and improving climate predictions. 展开更多
关键词 Regional Ocean Modeling System(ROMS) statistical atmospheric model tropical Pacific tropical instability wave(TIW)
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