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Phase field modeling of the aspect ratio dependent functional properties of NiTi shape memory alloys with different grain sizes 被引量:1
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作者 Bo Xu Beihai Huang +1 位作者 Chong Wang Qingyuan Wang 《Acta Mechanica Sinica》 2025年第1期22-41,共20页
It is well known that coarse-grained super-elastic NiTi shape memory alloys(SMAs)exhibit localized rather than homogeneous martensite transformation(MT),which,however,can be strongly influenced by either internal size... It is well known that coarse-grained super-elastic NiTi shape memory alloys(SMAs)exhibit localized rather than homogeneous martensite transformation(MT),which,however,can be strongly influenced by either internal size(grain size,GS)or the external size(geometric size).The coupled effect of GS and geometric size on the functional properties has not been clearly understood yet.In this work,the super-elasticity,one-way,and stress-assisted two-way shape memory effects of the polycrystalline NiTi SMAs with different aspect ratios(length/width for the gauge section)and different GSs are investigated based on the phase field method.The coupled effect of the aspect ratio and GS on the functional properties is adequately revealed.The simulated results indicate that when the aspect ratio is lower than about 4:1,the stress biaxiality and stress heterogeneity in the gauge section of the sample become more and more obvious with decreasing the aspect ratio,which can significantly influence the microstructure evolution in the process involving external stress.Therefore,the corresponding functional property is strongly dependent on the aspect ratio.With decreasing the GS and the aspect ratio(to be lower than 4:1),both the aspect ratio and GS can affect the MT or martensite reorientation in each grain and the interaction among grains.Thus,due to the strong internal constraint(i.e.,the constraint of grain boundary)and the external constraint(i.e.,the constraint of geometric boundary),the capabilities of the functional properties of NiTi SMAs are gradually weakened and highly dependent on these two factors. 展开更多
关键词 Phase field modeling NITI Aspect ratio Grain size functional property
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Pharmacological targeting cGAS/STING/NF-κB axis by tryptanthrin induces microglia polarization toward M2 phenotype and promotes functional recovery in a mouse model of spinal cord injury 被引量:1
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作者 Ziwei Fan Mengxian Jia +16 位作者 Jian Zhou Zhoule Zhu Yumin Wu Xiaowu Lin Yiming Qian Jiashu Lian Xin Hua Jianhong Dong Zheyu Fang Yuqing Liu Sibing Chen Xiumin Xue Juanqing Yue Minyu Zhu Ying Wang Zhihui Huang Honglin Teng 《Neural Regeneration Research》 SCIE CAS 2025年第11期3287-3301,共15页
The M1/M2 phenotypic shift of microglia after spinal cord injury plays an important role in the regulation of neuroinflammation during the secondary injury phase of spinal cord injury.Regulation of shifting microglia ... The M1/M2 phenotypic shift of microglia after spinal cord injury plays an important role in the regulation of neuroinflammation during the secondary injury phase of spinal cord injury.Regulation of shifting microglia polarization from M1(neurotoxic and proinflammatory type)to M2(neuroprotective and anti-inflammatory type)after spinal cord injury appears to be crucial.Tryptanthrin possesses an anti-inflammatory biological function.However,its roles and the underlying molecular mechanisms in spinal cord injury remain unknown.In this study,we found that tryptanthrin inhibited microglia-derived inflammation by promoting polarization to the M2 phenotype in vitro.Tryptanthrin promoted M2 polarization through inactivating the cGAS/STING/NF-κB pathway.Additionally,we found that targeting the cGAS/STING/NF-κB pathway with tryptanthrin shifted microglia from the M1 to M2 phenotype after spinal cord injury,inhibited neuronal loss,and promoted tissue repair and functional recovery in a mouse model of spinal cord injury.Finally,using a conditional co-culture system,we found that microglia treated with tryptanthrin suppressed endoplasmic reticulum stress-related neuronal apoptosis.Taken together,these results suggest that by targeting the cGAS/STING/NF-κB axis,tryptanthrin attenuates microglia-derived neuroinflammation and promotes functional recovery after spinal cord injury through shifting microglia polarization to the M2 phenotype. 展开更多
关键词 cGAS/STING functional recovery MICROGLIA neuroinflammation neuroprotection nuclear factor-κB POLARIZATION spinal cord injury TRYPTANTHRIN
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Resting-state brain network remodeling after different nerve reconstruction surgeries:a functional magnetic resonance imaging study in brachial plexus injury rats
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作者 Yunting Xiang Xiangxin Xing +6 位作者 Xuyun Hua Yuwen Zhang Xin Xue Jiajia Wu Mouxiong Zheng He Wang Jianguang Xu 《Neural Regeneration Research》 SCIE CAS 2025年第5期1495-1504,共10页
Distinct brain remodeling has been found after different nerve reconstruction strategies,including motor representation of the affected limb.However,differences among reconstruction strategies at the brain network lev... Distinct brain remodeling has been found after different nerve reconstruction strategies,including motor representation of the affected limb.However,differences among reconstruction strategies at the brain network level have not been elucidated.This study aimed to explore intranetwork changes related to altered peripheral neural pathways after different nerve reconstruction surgeries,including nerve repair,endto-end nerve transfer,and end-to-side nerve transfer.Sprague–Dawley rats underwent complete left brachial plexus transection and were divided into four equal groups of eight:no nerve repair,grafted nerve repair,phrenic nerve end-to-end transfer,and end-to-side transfer with a graft sutured to the anterior upper trunk.Resting-state brain functional magnetic resonance imaging was obtained 7 months after surgery.The independent component analysis algorithm was utilized to identify group-level network components of interest and extract resting-state functional connectivity values of each voxel within the component.Alterations in intra-network resting-state functional connectivity were compared among the groups.Target muscle reinnervation was assessed by behavioral observation(elbow flexion)and electromyography.The results showed that alterations in the sensorimotor and interoception networks were mostly related to changes in the peripheral neural pathway.Nerve repair was related to enhanced connectivity within the sensorimotor network,while end-to-side nerve transfer might be more beneficial for restoring control over the affected limb by the original motor representation.The thalamic-cortical pathway was enhanced within the interoception network after nerve repair and end-to-end nerve transfer.Brain areas related to cognition and emotion were enhanced after end-to-side nerve transfer.Our study revealed important brain networks related to different nerve reconstructions.These networks may be potential targets for enhancing motor recovery. 展开更多
关键词 brain functional networks end-to-end nerve transfer end-to-side nerve transfer independent component analysis nerve repair peripheral plexus injury resting-state functional connectivity
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A new damage constitutive model for rock strain softening based on an improved Logistic function
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作者 GUO Yun-peng LIU Dong-qiao +1 位作者 YANG Sheng-kai LI Jie-yu 《Journal of Central South University》 2025年第8期3070-3094,共25页
This study proposed a new and more flexible S-shaped rock damage evolution model from a phenomenological perspective based on an improved Logistic function to describe the characteristics of the rock strain softening ... This study proposed a new and more flexible S-shaped rock damage evolution model from a phenomenological perspective based on an improved Logistic function to describe the characteristics of the rock strain softening and damage process.Simultaneously,it established a constitutive model capable of describing the entire process of rock pre-peak compaction and post-peak strain softening deformation,considering the nonlinear effects of the initial compaction stage of rocks,combined with damage mechanics theory and effective medium theory.In addition,this research verified the rationality of the constructed damage constitutive model using results from uniaxial and conventional triaxial compression tests on Miluo granite,yellow sandstone,mudstone,and glutenite.The results indicate that based on the improved Logistic function,the theoretical damage model accurately describes the entire evolution of damage characteristics during rock compression deformation,from maintenance through gradual onset,accelerated development to deceleration and termination,in a simple and unified expression.At the same time,the constructed constitutive model can accurately simulate the stress-strain process of different rock types under uniaxial and conventional triaxial compression,and the theoretical model curve closely aligns with experimental data.Compared to existing constitutive models,the proposed model has significant advantages.The damage model parameters a,r and β have clear physical meanings and interact competitively,where the three parameters collectively determine the shape of the theoretical stress−strain curve. 展开更多
关键词 rock mechanics strain softening improved Logistic function S-shaped model damage evolution constitutive model
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Improving atmospheric pressure vertical correction model using Gaussian function 被引量:1
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作者 Baoshuang Zhang Junyu Li +6 位作者 Lilong Liu Yibin Yao Liangke Huang Chao Ren Hongchang He Tengxu Zhang Yuxin Wang 《Geodesy and Geodynamics》 2025年第1期67-74,共8页
The Zenith Hydrostatic Delay(ZHD)is essential for high-precision Global Navigation Satellite System(GNSS)and Very Long Baseline Interferometry(VLBI)data processing.Accurate estimation of ZHD relies on in situ atmosphe... The Zenith Hydrostatic Delay(ZHD)is essential for high-precision Global Navigation Satellite System(GNSS)and Very Long Baseline Interferometry(VLBI)data processing.Accurate estimation of ZHD relies on in situ atmospheric pressure,which is primarily variable in the vertical direction.Current atmospheric pressure is either site-specific or has limited spatial coverage,necessitating vertical corrections for broader applicability.This study introduces a model that uses a Gaussian function for the vertical correction of atmospheric pressure when in situ meteorological observations are unavailable.Validation with the fifth-generation European Centre for Medium-Range Weather Forecasts reanalysis(ERA5)reveals an average Bias and RMS for the new model of 0.31 h Pa and 2.96 h Pa,respectively.This corresponds to improvements of 37.5%and 80.3%in terms of RMS compared to two commonly used models(T0and Tvmodels)that require in situ meteorological observations,respectively.Additional validation with radiosonde data shows an average Bias and RMS of 1.85 h Pa and 4.87 h Pa,corresponding to the improvement of 42.8%and 71.1%in RMS compared with T0and Tv models,respectively.These accuracies are sufficient for calculating ZHD to an accuracy of 1 mm by performing atmospheric pressure vertical correction.The new model can correct atmospheric pressure from meteorological stations or numerical weather forecasts to different heights of the troposphere. 展开更多
关键词 ATMOSPHERIC pressure Vertical correction Zenith hydrostatic delay(ZHD) Gauss function ERA5
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Artificial hearing systems based on functional cochlea models
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作者 Jinke Chang Sita Tarini Clark +3 位作者 Iwan Roberts Filip Hrncirik Zhipeng Zhang Manohar Bance 《International Journal of Extreme Manufacturing》 2025年第1期73-94,共22页
The cochlea is one of the most complex organs in the human body,exhibiting a complex interplay of characteristics in acoustic,mechanical,electrical,and biological functions.Functional cochlea models are an essential p... The cochlea is one of the most complex organs in the human body,exhibiting a complex interplay of characteristics in acoustic,mechanical,electrical,and biological functions.Functional cochlea models are an essential platform for studying hearing mechanics and are crucial for developing next-generation auditory prostheses and artificial hearing systems for sensorineural hearing restoration.Recent advances in additive manufacturing,organ-on-a-chip models,drug delivery platforms,and artificial intelligence have provided valuable insights into how to manufacture artificial cochlea models that more accurately replicate the complex anatomy and physiology of the inner ear.This paper reviews recent advancements in the applications of advanced manufacturing techniques in reproducing the physical,biological,and intelligent functions of the cochlea.It also outlines the current challenges to developing mechanically,electrically,and anatomically accurate functional models of the inner ear.Finally,this review identifies the major requirements and outlook for impactful research in this field going forward.Through interdisciplinary collaboration and innovation,these functional cochlea models are poised to drive significant advancements in hearing treatments,and ultimately enhance the quality of life for individuals with hearing loss. 展开更多
关键词 functional cochlea model auditory system hearing loss advanced manufacturing artificial hearing
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Stability Analysis of an Epidemic Predator-Prey Model with Prey Dispersal and Holling Type-Ⅱ Functional Response
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作者 Lingshu WANG Mei ZHANG Ya-nan ZHANG 《Journal of Mathematical Research with Applications》 2025年第2期179-194,共16页
This paper examines an epidemic predator-prey model with prey dispersal and Holling type-II functional response. In this model, it is assumed that the predator population suffers a transmissible disease. By analyzing ... This paper examines an epidemic predator-prey model with prey dispersal and Holling type-II functional response. In this model, it is assumed that the predator population suffers a transmissible disease. By analyzing the corresponding characteristic equations, the local stability of each of feasible equilibria and the existence of Hopf bifurcations at the coexistence equilibrium is addressed. Using Lyapunov functionals and LaSalle's invariance principle, we obtained the sufficient conditions for the global stability of the trivial equilibrium, the predator-extinction equilibrium, the disease-free equilibrium and the coexistence equilibrium, respectively. The paper also includes numerical simulations to illustrate the analytical results. 展开更多
关键词 predator-prey model dispersal Holling type-II functional response Hopf bifurcation stability
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The effect of dispersal on a predator-prey model with Holling type-Ⅱ functional response
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作者 WANG Ling-shu ZHANG Mei +1 位作者 ZHANG Ya-nan WANG Yan 《Applied Mathematics(A Journal of Chinese Universities)》 2025年第3期602-616,共15页
A predator-prey model with prey dispersal and Holling type-Ⅱ functional response is investigated.In this model,the time delay due to the gestation of the predator and stagestructure for the predator are considered.By... A predator-prey model with prey dispersal and Holling type-Ⅱ functional response is investigated.In this model,the time delay due to the gestation of the predator and stagestructure for the predator are considered.By analyzing the corresponding characteristic equations,the local stability of each of the nonnegative equilibria is discussed.The existence of Hopf bifurcations at the positive equilibrium is established.By using Lyapunov functionals and LaSalle’s invariance principle,sufficient conditions are obtained for the global stability of the positive equilibrium,the nonnegative boundary equilibrium and the trivial equilibrium of the model,respectively.Numerical simulations are carried out to illustrate the main results. 展开更多
关键词 predator-prey model dispersal Holling type-Ⅱfunctional response time delay STAGE-STRUCTURE STABILITY
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Generalized Functional Linear Models:Efficient Modeling for High-dimensional Correlated Mixture Exposures
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作者 Bingsong Zhang Haibin Yu +11 位作者 Xin Peng Haiyi Yan Siran Li Shutong Luo Renhuizi Wei Zhujiang Zhou Yalin Kuang Yihuan Zheng Chulan Ou Linhua Liu Yuehua Hu Jindong Ni 《Biomedical and Environmental Sciences》 2025年第8期961-976,共16页
Objective Humans are exposed to complex mixtures of environmental chemicals and other factors that can affect their health.Analysis of these mixture exposures presents several key challenges for environmental epidemio... Objective Humans are exposed to complex mixtures of environmental chemicals and other factors that can affect their health.Analysis of these mixture exposures presents several key challenges for environmental epidemiology and risk assessment,including high dimensionality,correlated exposure,and subtle individual effects.Methods We proposed a novel statistical approach,the generalized functional linear model(GFLM),to analyze the health effects of exposure mixtures.GFLM treats the effect of mixture exposures as a smooth function by reordering exposures based on specific mechanisms and capturing internal correlations to provide a meaningful estimation and interpretation.The robustness and efficiency was evaluated under various scenarios through extensive simulation studies.Results We applied the GFLM to two datasets from the National Health and Nutrition Examination Survey(NHANES).In the first application,we examined the effects of 37 nutrients on BMI(2011–2016 cycles).The GFLM identified a significant mixture effect,with fiber and fat emerging as the nutrients with the greatest negative and positive effects on BMI,respectively.For the second application,we investigated the association between four pre-and perfluoroalkyl substances(PFAS)and gout risk(2007–2018 cycles).Unlike traditional methods,the GFLM indicated no significant association,demonstrating its robustness to multicollinearity.Conclusion GFLM framework is a powerful tool for mixture exposure analysis,offering improved handling of correlated exposures and interpretable results.It demonstrates robust performance across various scenarios and real-world applications,advancing our understanding of complex environmental exposures and their health impacts on environmental epidemiology and toxicology. 展开更多
关键词 Mixture exposure modeling functional data analysis High-dimensional data Correlated exposures Environmental epidemiology
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Risk factors and predictive modeling of early postoperative liver function abnormalities
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作者 Lin Zhong Hao-Yuan Wang +5 位作者 Xiao-Na Li Qiong Ling Ning Hao Xiang-Yu Li Gao-Feng Zhao Min Liao 《World Journal of Hepatology》 2025年第8期233-243,共11页
BACKGROUND Research has shown that several factors can influence postoperative abnormal liver function;however,most studies on this issue have focused specifically on hepatic and cardiac surgeries,leaving limited rese... BACKGROUND Research has shown that several factors can influence postoperative abnormal liver function;however,most studies on this issue have focused specifically on hepatic and cardiac surgeries,leaving limited research on contributing factors in other types of surgeries.AIM To identify the risk factors for early postoperative abnormal liver function in multiple surgery types and construct a risk prediction model.METHODS This retrospective cohort study involved 3720 surgical patients from 5 surgical departments at Guangdong Provincial Hospital of Traditional Chinese Medicine.Patients were divided into abnormal(n=108)and normal(n=3612)groups based on liver function post-surgery.Univariate analysis and LASSO regression screened variables,followed by logistic regression to identify risk factors.A prediction model was constructed based on the variables selected via logistic re-gression.The goodness-of-fit of the model was evaluated using the Hosm-er–Lemeshow test,while discriminatory ability was measured by the area under the receiver operating characteristic curve.Calibration curves were plotted to visualize the consistency between predicted probabilities and observed outcomes.RESULTS The key factors contributing to abnormal liver function after surgery include elevated aspartate aminotransferase and alanine aminotransferase levels and reduced platelet counts pre-surgery,as well as the sevoflurane use during the procedure,among others.CONCLUSION The above factors collectively represent notable risk factors for postoperative liver function injury,and the prediction model developed based on these factors demonstrates strong predictive efficacy. 展开更多
关键词 Perioperative period Abnormal liver function Risk factor Univariate analysis Risk prediction model
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Functional evidential reasoning model(FERM)-A new systematic approach for exploring hazardous chemical operational accidents under uncertainty
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作者 Qianlin Wang Jiaqi Han +6 位作者 Lei Cheng Feng Wang Yiming Chen Zhan Dou Bing Zhang Feng Chen Guoan Yang 《Chinese Journal of Chemical Engineering》 2025年第5期255-269,共15页
This paper proposed a new systematic approach-functional evidential reasoning model(FERM) for exploring hazardous chemical operational accidents under uncertainty. First, FERM was introduced to identify various causal... This paper proposed a new systematic approach-functional evidential reasoning model(FERM) for exploring hazardous chemical operational accidents under uncertainty. First, FERM was introduced to identify various causal factors and their performance changes in hazardous chemical operational accidents, along with determining the functional failure link relationships. Subsequently, FERM was employed to elucidate both qualitative and quantitative operational accident information within a unified framework, which could be regarded as the input of information fusion to obtain the fuzzy belief distribution of each cause factor. Finally, the derived risk values of the causal factors were ranked while constructing multi-level accident causation chains to unveil the weak links in system functionality and the primary roots of operational accidents. Using the specific case of the “1·15” major explosion and fire accident at Liaoning Panjin Haoye Chemical Co., Ltd., seven causal factors and their corresponding performance changes were identified. Additionally, five accident causation chains were uncovered based on the fuzzy joint distribution of the functional assessment level(FAL) and reliability distribution(RD),revealing an overall increase in risk along the accident evolution path. The research findings demonstrated that FERM enabled the effective characterization, rational quantification and accurate analysis of the inherent uncertainties in hazardous chemical operational accident risks from a systemic perspective. 展开更多
关键词 functional evidential reasoning model (FERM) Accident causation analysis Operational accidents Hazardous chemical UNCERTAINTY
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Optimizing basis wave functions in the generator coordinate method for microscopic cluster models (Ⅰ)
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作者 Yi‑Fan Liu Bo Zhou Yu‑Gang Ma 《Nuclear Science and Techniques》 2025年第10期183-191,共9页
We employed random distributions and gradient descent methods for the Generator Coordinate Method(GCM)to identify effective basis wave functions,taking halo nuclei ^(6)He and ^(6)Li as examples.By comparing the ground... We employed random distributions and gradient descent methods for the Generator Coordinate Method(GCM)to identify effective basis wave functions,taking halo nuclei ^(6)He and ^(6)Li as examples.By comparing the ground state(0^(+))energy of ^(6)He and the excited state(0^(+))energy of 6 Li calculated with various random distributions and manually selected generation coordinates,we found that the heavy tail characteristic of the logistic distribution better describes the features of the halo nuclei.Subsequently,the Adam algorithm from machine learning was applied to optimize the basis wave functions,indicating that a limited number of basis wave functions can approximate the converged values.These results offer some empirical insights for selecting basis wave functions and contribute to the broader application of machine learning methods in predicting effective basis wave functions. 展开更多
关键词 Generator Coordinate Method Effective basis wave functions Nuclear cluster model Machine learning Halo nuclei
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Nonlocal Thermal–Mechanical Vibration of Spinning Functionally Graded Nanotubes Conveying Fluid Based on the Timoshenko Model
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作者 Yao Chen Xiao-Dong Yang Feng Liang 《Acta Mechanica Solida Sinica》 2025年第5期776-788,共13页
Based on the Timoshenko beam theory,this paper proposes a nonlocal bi-gyroscopic model for spinning functionally graded(FG)nanotubes conveying fluid,and the thermal–mechanical vibration and stability of such composit... Based on the Timoshenko beam theory,this paper proposes a nonlocal bi-gyroscopic model for spinning functionally graded(FG)nanotubes conveying fluid,and the thermal–mechanical vibration and stability of such composite nanostructures under small scale,rotor,and temperature coupling effects are investigated.The nanotube is composed of functionally graded materials(FGMs),and different volume fraction functions are utilized to control the distribution of material properties.Eringen’s nonlocal elasticity theory and Hamilton’s principle are applied for dynamical modeling,and the forward and backward precession frequencies as well as 3D mode configurations of the nanotube are obtained.By conducting dimensionless analysis,it is found that compared to the Timoshenko nano-beam model,the conventional Euler–Bernoulli(E-B)model holds the same flutter frequency in the supercritical region,while it usually overestimates the higher-order precession frequencies.The nonlocal,thermal,and flowing effects all can lead to buckling or different kinds of coupled flutter in the system.The material distribution of the P-type FGM nanotube can also induce coupled flutter,while that of the S-type FGM nanotube has no impact on the stability of the system.This paper is expected to provide a theoretical foundation for the design of motional composite nanodevices. 展开更多
关键词 Bi-gyroscopic nanotube Thermal–mechanical vibration functionally graded material Timoshenko model Spinning motion Nonlocal effect
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Numerical simulation of the fluid and flexible rods interaction using a semi-resolved coupling model promoted by anisotropic Gaussian kernel function
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作者 Caiping Jin Jingxin Zhang Yonglin Sun 《Theoretical & Applied Mechanics Letters》 2025年第1期5-8,共4页
The numerical simulation of the fluid flow and the flexible rod(s)interaction is more complicated and has lower efficiency due to the high computational cost.In this paper,a semi-resolved model coupling the computatio... The numerical simulation of the fluid flow and the flexible rod(s)interaction is more complicated and has lower efficiency due to the high computational cost.In this paper,a semi-resolved model coupling the computational fluid dynamics and the flexible rod dynamics is proposed using a two-way domain expansion method.The gov-erning equations of the flexible rod dynamics are discretized and solved by the finite element method,and the fluid flow is simulated by the finite volume method.The interaction between fluids and solid rods is modeled by introducing body force terms into the momentum equations.Referred to the traditional semi-resolved numerical model,an anisotropic Gaussian kernel function method is proposed to specify the interactive forces between flu-ids and solid bodies for non-circle rod cross-sections.A benchmark of the flow passing around a single flexible plate with a rectangular cross-section is used to validate the algorithm.Focused on the engineering applications,a test case of a finite patch of cylinders is implemented to validate the accuracy and efficiency of the coupled model. 展开更多
关键词 Semi-resolved coupling model Two-way domain expansion method Anisotropic Gaussian kernel function Flexible rod(s)
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Size-dependent axisymmetric bending and buckling analysis of functionally graded sandwich Kirchhoff nanoplates using nonlocal strain gradient integral model
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作者 Chang LI Hai QING 《Applied Mathematics and Mechanics(English Edition)》 2025年第3期467-484,共18页
This paper extends the one-dimensional(1D)nonlocal strain gradient integral model(NStraGIM)to the two-dimensional(2D)Kirchhoff axisymmetric nanoplates,based on nonlocal strain gradient integral relations formulated al... This paper extends the one-dimensional(1D)nonlocal strain gradient integral model(NStraGIM)to the two-dimensional(2D)Kirchhoff axisymmetric nanoplates,based on nonlocal strain gradient integral relations formulated along both the radial and circumferential directions.By transforming the proposed integral constitutive equations into the equivalent differential forms,complemented by the corresponding constitutive boundary conditions(CBCs),a well-posed mathematical formulation is established for analyzing the axisymmetric bending and buckling of annular/circular functionally graded(FG)sandwich nanoplates.The boundary conditions at the inner edge of a solid nanoplate are derived by L'H?spital's rule.The numerical solution is obtained by the generalized differential quadrature method(GDQM).The accuracy of the proposed model is validated through comparison with the data from the existing literature.A parameter study is conducted to demonstrate the effects of FG sandwich parameters,size parameters,and nonlocal gradient parameters. 展开更多
关键词 size effect nonlocal strain gradient integral model(NStraGIM) BENDING buckling Kirchhoff annular/circular nanoplate functionally graded(FG)sandwich material
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Rock cracking simulation in tension and compression by peridynamics using a novel contact-friction model with a twin mesh and potential functions
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作者 Feng Tian Zaobao Liu +1 位作者 Jinxin Zhou Jianfu Shao 《Journal of Rock Mechanics and Geotechnical Engineering》 2025年第6期3395-3419,共25页
Peridynamics(PD)is an effective method for simulating the spontaneous initiation and propagation of tensile cracks in materials.However,it faces great challenges in simulating compression-shear cracking of geomaterial... Peridynamics(PD)is an effective method for simulating the spontaneous initiation and propagation of tensile cracks in materials.However,it faces great challenges in simulating compression-shear cracking of geomaterials due to the lack of efficient contact-friction models.This paper introduces an original contact-friction model that leverages twin mesh and potential function principles within PD to model rock cracking under tensile and compressive stresses.The contact detection algorithm,based on space segmentation axis-aligned bounding box(AABB)tree data structure,is used to address the significant challenge of highly efficient contact detection in compression and shear problems.In this method,the twin mesh and potential function are utilized to quantify contact detection and contact degree,as well as friction behavior.This is in contrast to the distance and circular contact area model,which lacks physical significance in the classical PD method.As demonstrated by the tests on specimens containing cracks,the proposed model can capture 8 types of secondary fractures,reduce the contact detection error by about 29%e56%,and increase the contact retrieval efficiency by over 1600 times compared to the classic PD models.This significantly enhances the capability of PD to simulate the initiation,expansion,and coalescence of intricate compression-shear cracks. 展开更多
关键词 Peridynamics(PD) Rock cracking modeling Compression-shear modeling Cracking modeling of geomaterials Contact detection algorithm Contact-friction model
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Environmental interpretation of spatial heterogeneity in the trade-offs and synergies of land use functions:A study based on the XGBoost-SHAP model
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作者 FENG Haoyuan ZHANG Xuebin +2 位作者 SHI Peiji SHI Jing WANG Ziyang 《Journal of Arid Land》 2025年第10期1378-1401,共24页
Accurately revealing the spatial heterogeneity in the trade-offs and synergies of land use functions(LUFs)and their driving factors is imperative for advancing sustainable land utilization and optimizing land use plan... Accurately revealing the spatial heterogeneity in the trade-offs and synergies of land use functions(LUFs)and their driving factors is imperative for advancing sustainable land utilization and optimizing land use planning.This is especially critical for ecologically vulnerable inland river basins in arid regions.However,existing methods struggle to effectively capture complex nonlinear interactions among environmental factors and their multifaceted relationships with trade-offs and synergies of LUFs,especially for the inland river basins in arid regions.Consequently,this study focused on the middle reaches of the Heihe River Basin(MHRB),an arid inland river basin in northwestern China.Using land use,socioeconomic,meteorological,and hydrological data from 2000 to 2020,we analyzed the spatiotemporal patterns of LUFs and their trade-off and synergy relationships from the perspective of production,living,ecological functions.Additionally,we employed an integrated Extreme Gradient Boosting(XGBoost)-SHapley Additive exPlanations(SHAP)framework to investigate the environmental factors influencing the spatial heterogeneity in the trade-offs and synergies of LUFs.Our findings reveal that from 2000 to 2020,the production,living,and ecological functions of land use within the MHRB exhibited an increasing trend,demonstrating a distinct spatial pattern of''high in the southwest and low in the northeast''.Significant spatial heterogeneity defined the trade-off and synergistic relationships,with trade-offs dominating human activity-intensive oasis areas,while synergies prevailed in other areas.During the study period,synergistic relationships between production and living functions and between production and ecological functions were relatively robust,whereas synergies in living-ecological functions remained weaker.Natural factors(digital elevation model(DEM),annual mean temperature,Normalized Difference Vegetation Index(NDVI),and annual precipitation)emerged as the primary factors driving the trade-offs and synergies of LUFs,followed by socioeconomic factors(population density,Gross Domestic Product(GDP),and land use intensity),while distance factors(distance to water bodies,distance to residential areas,and distance to roads)exerted minimal influence.Notably,the interactions among NDVI,annual mean temperature,DEM,and land use intensity exerted the most substantial impacts on the relationships among LUFs.This study provides novel perspectives and methodologies for unraveling the mechanisms underlying the spatial heterogeneity in the trade-offs and synergies of LUFs,offering scientific insights to inform regional land use planning and sustainable natural resource management in inland river basins in arid regions. 展开更多
关键词 production function living function ecological function trade-offs and synergies Extreme Gradient Boosting(XGBoost) SHapley Additive exPlanations(SHAP) Heihe River Basin
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The effect of adsorbent textural and functional properties on model naphthenic acid adsorption
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作者 Tyler M.Roy Elmira Nazari +2 位作者 Oliver K.L.Strong Paul R.Pede Andrew J.Vreugdenhil 《Journal of Environmental Sciences》 2025年第2期27-37,共11页
Naphthenic acids,NAs,are a major contaminant of concern and a focus of much research around remediation of oil sand process affected waters,OSPW.Using activated carbon adsorbents are an attractive option given their l... Naphthenic acids,NAs,are a major contaminant of concern and a focus of much research around remediation of oil sand process affected waters,OSPW.Using activated carbon adsorbents are an attractive option given their low cost of fabrication and implementation.A deeper evaluation of the effect NA structural differences have on uptake affinity is warranted.Here we provide an in-depth exploration of NA adsorption including many more model NA species than have been assessed previously with evaluation of adsorption kinetics and isotherms at the relevant alkaline pH of OSPW using several different carbon adsorbents with pH buffering to simulate the behaviour of real OSPW.Uptake for the NA varied considerably regardless of the activated carbon used,ranging from 350 mg/g to near zero highlighting recalcitrant NAs.The equilibrium data was explored to identify structural features of these species and key physiochemical properties that influence adsorption.We found that certainNAwill be resistant to adsorptionwhen hydrophobic adsorbents are used.Adsorption isotherm modelling helped explore interactions occurring at the interface between NA and adsorbent surfaces.We identified the importance of NA hydrophobicity for activated carbon uptake.Evidence is also presented that indicates favorable hydrogen bonding between certain NA and surface site hydroxyl groups,demonstrating the importance of adsorbent surface functionality for NA uptake.This research highlights the challenges associated with removing NAs from OSPW through adsorption and also identifies howadsorbent surface chemistry modification can be used to increase the removal efficiency of recalcitrant NA species. 展开更多
关键词 ADSORPTION Activated carbon model naphthenic acids Isotherm modelling
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Advanced Computational Modeling and Mechanical Behavior Analysis of Multi-Directional Functionally Graded Nanostructures:A Comprehensive Review
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作者 Akash Kumar Gartia S.Chakraverty 《Computer Modeling in Engineering & Sciences》 2025年第3期2405-2455,共51页
This review explores multi-directional functionally graded(MDFG)nanostructures,focusing on their material characteristics,modeling approaches,and mechanical behavior.It starts by classifying different types of functio... This review explores multi-directional functionally graded(MDFG)nanostructures,focusing on their material characteristics,modeling approaches,and mechanical behavior.It starts by classifying different types of functionally graded(FG)materials such as conventional,axial,bi-directional,and tri-directional,and the material distribution models like power-law,exponential,trigonometric,polynomial functions,etc.It also discusses the application of advanced size-dependent theories like Eringen’s nonlocal elasticity,nonlocal strain gradient,modified couple stress,and consistent couple stress theories,which are essential to predict the behavior of structures at small scales.The review covers the mechanical analysis of MDFG nanostructures in nanobeams,nanopipes,nanoplates,and nanoshells and their dynamic and static responses under different loading conditions.The effect of multi-directional material gradation on stiffness,stability and vibration is discussed.Moreover,the review highlights the need for more advanced analytical,semi-analytical,and numerical methods to solve the complex vibration problems ofMDFG nanostructures.It is evident that the continued development of these methods is crucial for the design,optimization,and real-world application of MDFG nanostructures in advanced engineering fields like aerospace,biomedicine,and micro/nanoelectromechanical systems(MEMS/NEMS).This study is a reference for researchers and engineers working in the domain of MDFG nanostructures. 展开更多
关键词 functionally graded multi-directional nano SIZE-DEPENDENT VIBRATION
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Artificial intelligence model on images of functional dyspepsia
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作者 Hiroshi Mihara Sohachi Nanjo +3 位作者 Iori Motoo Takayuki Ando Haruka Fujinami Ichiro Yasuda 《Artificial Intelligence in Gastrointestinal Endoscopy》 2025年第1期1-11,共11页
BACKGROUND Recently,it has been suggested that the duodenum may be the pathological locus of functional dyspepsia(FD).Additionally,an image-based artificial intelligence(AI)model was shown to discriminate colonoscopy ... BACKGROUND Recently,it has been suggested that the duodenum may be the pathological locus of functional dyspepsia(FD).Additionally,an image-based artificial intelligence(AI)model was shown to discriminate colonoscopy images of irritable bowel syndrome from healthy subjects with an area under the curve(AUC)0.95.AIM To evaluate an AI model to distinguish duodenal images of FD patients from healthy subjects.METHODS Duodenal images were collected from hospital records and labeled as"functional dyspepsia"or non-FD in electronic medical records.Helicobacter pylori(HP)infection status was obtained from the Japan Endoscopy Database.Google Cloud AutoML Vision was used to classify four groups:FD/HP current infection(n=32),FD/HP uninfected(n=35),non-FD/HP current infection(n=39),and non-FD/HP uninfected(n=33).Patients with organic diseases(e.g.,cancer,ulcer,postoperative abdomen,reflux)and narrow-band or dye-spread images were excluded.Sensitivity,specificity,and AUC were calculated.RESULTS In total,484 images were randomly selected for FD/HP current infection,FD/HP uninfected,non-FD/current infection,and non-FD/HP uninfected.The overall AUC for the four groups was 0.47.The individual AUC values were as follows:FD/HP current infection(0.20),FD/HP uninfected(0.35),non-FD/current infection(0.46),and non-FD/HP uninfected(0.74).Next,using the same images,we constructed models to determine the presence or absence of FD in the HP-infected or uninfected patients.The model exhibited a sensitivity of 58.3%,specificity of 100%,positive predictive value of 100%,negative predictive value of 77.3%,and an AUC of 0.85 in HP uninfected patients.CONCLUSION We developed an image-based AI model to distinguish duodenal images of FD from healthy subjects,showing higher accuracy in HP-uninfected patients.These findings suggest AI-assisted endoscopic diagnosis of FD may be feasible. 展开更多
关键词 Artificial Intelligence Cloud-based DUODENUM functional dyspepsia
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