In the context of global change,a central challenge in ecology is to establish the multi-scale evolution and coupling mechanisms of ecosystems.In particular,it is necessary to clarify the structural mismatch between h...In the context of global change,a central challenge in ecology is to establish the multi-scale evolution and coupling mechanisms of ecosystems.In particular,it is necessary to clarify the structural mismatch between hierarchical levels that arises when ecological networks(ENs)are constructed across varying extents or grains.Using city-and central urban-level examples,we introduced a cross-level ENs spatial mismatch measurement index(SMI)and a scale-effect analysis framework.Five representative cities from the Northeast,Northwest,Central,Southwest,and Southeast China were selected as research areas.A unified approach combining minimum cumulative resistance and XGBoost models enable the preliminary construction of two-level ENs.SMI is then applied to evaluate cross-level mismatches,followed by analysis of extent and grain effects.Mechanisms underlying EN disconnection and potential solution pathways are further examined.The results show that:(1)spatial mismatch indicators(SMI_source,SMI_corridor,SMI_nodes)defined on ecological source areas(ESA),corridor,and strategic nodes,reflect mismatch degrees across EN levels;(2)scale effects reveal decreasing SMI with expanding observation extent in central urban area,fluctuating values with synchronous change in data grain,and increasing values with higher statistical grid density;(3)the largest patch index and landscape division index exert a strong influence on SMI_source,while patch number and Shannon's diversity index play key roles in SMI_corridor;and(4)variation in landscape composition and configuration heterogeneity across scales provides explanatory power of mismatch phenomenon and scale effects.The study contributes to ecological pattern analysis by offering a quantitative method for multi-scale EN research,with implications for ecological protection and regional landscape planning.展开更多
Multilayer structures composed of quasi-zero-stiffness(QZS)units exhibit mechanical characteristics distinct from those of a single unit,and their behaviors are governed by the coupling mechanism between the QZS units...Multilayer structures composed of quasi-zero-stiffness(QZS)units exhibit mechanical characteristics distinct from those of a single unit,and their behaviors are governed by the coupling mechanism between the QZS units.This paper introduces the coupling coefficient to quantitatively describe this mechanism,classifying the system into strongly coupled and weakly coupled states.Through theoretical analysis,numerical simulation,and experimental testing,the static and dynamic responses under different coupling states are comparatively investigated.The results show that in the strongly coupled system,the deformation behavior of each QZS unit shows high consistency,leading to a wider QZS region,weaker nonlinear characteristics,and stronger dynamic response.In the weakly coupled systems,the low degree of deformation coordinations among the units results in different QZS regions,enabling low-frequency vibration isolation under varying loads.The analytical approach of the coupling mechanisms and the static and dynamic response behaviors generated by the two coupling mechanisms provide guidance for the structural design of multifunctional and highly adaptable multi-level QZS metamaterials.展开更多
In structural optimization,data-driven surrogate models are often explored as alternatives to finite element analysis to reduce computational cost.However,conventional neural networks usually fail to capture key struc...In structural optimization,data-driven surrogate models are often explored as alternatives to finite element analysis to reduce computational cost.However,conventional neural networks usually fail to capture key structural characteristics and are limited to predicting global responses(e.g.,top displacement),but usually fail to achieve accurate internal force predictions with conventional training data volumes.As a result,most existing studies involving surrogate models did not concern internal force constraints.To address this issue,this study proposes a structural optimization framework based on a pre-trained Physics-Informed Neural Network(PINN)surrogate model.By embedding static equilibrium equation into the loss function,the model achieves higher predictive accuracy,particularly for internal forces,while pre-training accelerates convergence and enhances stability.Combined with an improved multi-swarm particle swarm optimization(MPSO)algorithm,the framework enables efficient optimization of multi-story frame structures under internal force and multiple other constraints.The application to a six-story frame structure validates its effectiveness:compared with a DNN-based model,the PINN-based model improves the coefficient of determination for internal force prediction from 0.8874 to 0.9937.These results demonstrate that the proposed method offers a promising approach for efficient optimization of multi-story frame structures.展开更多
Evaluation of compressive strength in underground lining structures is critical for ensuring structural integrity and safety.Traditional assessment methods are often destructive,time-consuming,and impractical in confi...Evaluation of compressive strength in underground lining structures is critical for ensuring structural integrity and safety.Traditional assessment methods are often destructive,time-consuming,and impractical in confined environments such as tunnels and utility corridors.This study introduces an automated,nondestructive approach to visualize and estimate the compressive strength of underground concrete lining using hyperspectral imaging(HSI)combined with deep neural network(DNN)models.High-dimensional spectral data of concrete lining are assembled and trained to develop two DNN-based regression models,namely the Mono-Spectrum Deep Neural Regressor(MS-DNR)and the Segmented-Spectrum Deep Neural Regressor(SegS_DNR).Utilizing the SegS_DNR model,two-dimensional(2D)compressive strength distribution heatmaps were generated for visualization and assessment of strength variations.The SegS_DNR model demonstrated excellent predictive performance,achieving a coefficient of determination(Rp²)of 0.925 and a Residual Prediction Deviation(RPD)of 5.28 on the testing set for compressive strength estimation.The idea is further validated in site by investigating the capability of identifying the defect regions of the tunnel concrete lining,namely the cracked,spalling,and leaking areas,and demonstrated promising performance in comparison with experienced inspectors on site.This approach offers a contact-free technique for automated structural health monitoring,contributing to safer and more sustainable underground maintenance practices.展开更多
Cerebral small vessel disease(CSVD)encompasses a spectrum of pathological processes that affect the small arteries,capillaries,and venules of the brain.The neuroimaging features include white matter hyperintensities(W...Cerebral small vessel disease(CSVD)encompasses a spectrum of pathological processes that affect the small arteries,capillaries,and venules of the brain.The neuroimaging features include white matter hyperintensities(WMH),lacunar infarcts,cerebral microbleeds,and enlarged perivascular spaces.展开更多
With the rapid growth of technologies requiring high-power energy storage,achieving long-term cyclic stability under ultra-high current density is a key challenge.Aqueous zinc-ion batteries(AZIBs)are promising candida...With the rapid growth of technologies requiring high-power energy storage,achieving long-term cyclic stability under ultra-high current density is a key challenge.Aqueous zinc-ion batteries(AZIBs)are promising candidates due to their intrinsic safety and low cost,but they suffer from severe interfacial instability at rates exceeding 10 mA cm-2,which drastically shortens their cycle life.Inspired by theoretical calculations,triglyme(TGDE)additive with strong electron-donating groups into Zn(OTf)2 electrolytes effectively disrupts the hydrogen-bond network among free water molecules,while the weak coordination of TGDE with Zn2+promotes the entry of OTf-into the primary Zn2+solvated sheath,thus decreasing the coordination number of water with Zn2+.As such,the hydrogen-bond network and the bulk solvated structure are reconstructed with better stability.Moreover,the strong adsorption of TGDE lying on the Zn(002)surface would induce Zn depositions along(002)together with the reduced exposed surface,further effectively inhibiting side reactions.Likewise,TGDE electrolyte induces the formation of such ZnF2-ZnS dual-layer solid electrolyte interface(SEI)with superior chemical stability and ionic conductivity,thereby regulating Zn2+flux with dendrite-free depositions.Based on this electrolyte,Zn‖Zn cells can be stably cycled for 1300 h at a limit of 10 mA cm-2 and 10 mAh cm-2.The assembled Zn‖V2O5 full cells still maintain 99.9%capacity retention after 1000 cycles at 10 A g-1.This work provides a feasible approach for designing aqueous electrolytes to reconstruct the hydrogen-bond network and solvated structure,which can be extended to the applications of high-rate and high-temperature scenarios.展开更多
In this study,an architecture featuring a gradient conductive network structure and three-dimensional dual-continuous network structure is constructed in a carbon nanotubes/cellulose-boron nitride/poly(vinyl alcohol)(...In this study,an architecture featuring a gradient conductive network structure and three-dimensional dual-continuous network structure is constructed in a carbon nanotubes/cellulose-boron nitride/poly(vinyl alcohol)(CNT/cellulose-BN/PVA)composite.Using cellulose aerogel as a template,CNT were incorporated into the cellulose template by vertically impregnating the CNT suspension.Following the impregnation of BN/PVA and high-pressure compression,three-dimensional dual-continuous network structure was successfully constructed in the CNT/cellulose-BN/PVA composite.The comprehensive performance of the composite,including electromagnetic interference(EMI)shielding and Joule heating performance,was investigated.The results indicate that the total EMI shielding effectiveness(SE)for the CNT/cellulose-BN/PVA composite reveals similar values for electromagnetic waves incident from different directions,but totally different shielding mechanisms.For the CNT/cellulose-BN/PVA composite with three impregnation cycles of CNT,the EMI SE values exceeded 39 dB for electromagnetic waves incident from both the high-and low-CNT-content sides.93%of the microwaves were reflected when electromagnetic waves were incident from the high-CNT-content side,while the reflection coefficient decreased to 0.44 for the transverse direction.In addition,the construction of the dual-continuous network structure enabled the composite to exhibit both excellent electrical conductivity and good thermal conductivity simultaneously,endowing the material with good Joule heating performance.CNT/cellulose-BN/PVA composite films have significant potential for application as EMI shielding materials in extremely cold weather.展开更多
Graph neural networks(GNNs)often suffer from performance degradation due to the incompleteness of node features and structure relationships in the real world.Recently emerged graph completion learning(GCL)enhances the...Graph neural networks(GNNs)often suffer from performance degradation due to the incompleteness of node features and structure relationships in the real world.Recently emerged graph completion learning(GCL)enhances the generalization of GNNs by reconstructing the missing node features or structure relationships.Nevertheless,these proposed GCL methods are supervised by a large number of labeled nodes,which limits their applications in extremely limited labeled nodes.Moreover,the existing GCL methods either focus on feature missing or structure missing tasks,and little effort was paid to more challenging scenarios where both node features and structure relationships are simultaneously missing.In this paper,a general GCL framework with the aid of multi-level contrast graph mask autoencoders(EWS-RGCN)is proposed to improve the generalization of GNNs guided by extremely weak supervision on graphs with features and structure missing.Specifically,to alleviate the mutual interference between missing node features and structure relationships caused by message passing of GNNs,we separate the feature and structure completion into two channels.Then,a multi-level contrastive loss is introduced to simultaneously maximize the mutual information between nodes from the encoding and decoding stage,which can discover more effective supervision information from the data itself for EWS-RGCN optimization,apart from label information.To further enhance the space consistency between reconstructed node features and structure relationships,the inter-channel information cooperation module is introduced to enhance the mutual learning of feature and structure completion channels.Extensive experiments on six benchmarks demonstrate the effectiveness of our EWS-RGCN.展开更多
An efficient data-driven numerical framework is developed for transient heat conduction analysis in thin-walled structures.The proposed approach integrates spectral time discretization with neural network approximatio...An efficient data-driven numerical framework is developed for transient heat conduction analysis in thin-walled structures.The proposed approach integrates spectral time discretization with neural network approximation,forming a spectral-integrated neural network(SINN)scheme tailored for problems characterized by long-time evolution.Temporal derivatives are treated through a spectral integration strategy based on orthogonal polynomial expansions,which significantly alleviates stability constraints associated with conventional time-marching schemes.A fully connected neural network is employed to approximate the temperature-related variables,while governing equa-tions and boundary conditions are enforced through a physics-informed loss formulation.Numerical investigations demonstrate that the proposed method maintains high accuracy even when large time steps are adopted,where standard numerical solvers often suffer from instability or excessive computational cost.Moreover,the framework exhibits strong robustness for ultrathin configurations with extreme aspect ratios,achieving relative errors on the order of 10−5 or lower.These results indicate that the SINN framework provides a reliable and efficient alternative for transient thermal analysis of thin-walled structures under challenging computational conditions.展开更多
Multilayer complex dynamical networks,characterized by the intricate topological connections and diverse hierarchical structures,present significant challenges in determining complete structural configurations due to ...Multilayer complex dynamical networks,characterized by the intricate topological connections and diverse hierarchical structures,present significant challenges in determining complete structural configurations due to the unique functional attributes and interaction patterns inherent to different layers.This paper addresses the critical question of whether structural information from a known layer can be used to reconstruct the unknown intralayer structure of a target layer within general weighted output-coupling multilayer networks.Building upon the generalized synchronization principle,we propose an innovative reconstruction method that incorporates two essential components in the design of structure observers,the cross-layer coupling modulator and the structural divergence term.A key advantage of the proposed reconstruction method lies in its flexibility to freely designate both the unknown target layer and the known reference layer from the general weighted output-coupling multilayer network.The reduced dependency on full-state observability enables more deployment in engineering applications with partial measurements.Numerical simulations are conducted to validate the effectiveness of the proposed structure reconstruction method.展开更多
Machine learning provides a fast and accurate tool for the prediction of a physical model.In this paper,a machine learning framework based on the physics-informed neural network(PINN)was established to predict the lin...Machine learning provides a fast and accurate tool for the prediction of a physical model.In this paper,a machine learning framework based on the physics-informed neural network(PINN)was established to predict the linear elastic static deformation of plate and shell structures.In contrast to the purely data-driven neural network,PINN incorporates the physical laws into the training process,thus reducing the required amount of data.The loss functions of the PINN are constructed based on the total potential energy functions of the thin-walled structure.Besides,the proposed PINN can be easily extended to shell structures with multiple patches by adding interface compatibility constraints into the loss function.The performance of the PINNs with the energy-based loss functions was evaluated with different shell structures and compared with the finite element results.Numerical examples show that the highly accurate results can be achieved based on the proposed framework which significantly reduces the amount of required training data compared to the data-driven neural network.展开更多
Urban spatial morphology(USM)optimization is critical to balancing biodiversity conservation and sustainable urbanization.However,previous studies predominantly focused on the socio-economic efficiency and static ecol...Urban spatial morphology(USM)optimization is critical to balancing biodiversity conservation and sustainable urbanization.However,previous studies predominantly focused on the socio-economic efficiency and static ecological metrics and rarely addressed the dynamic USM optimization across spatial scales.Here,we developed a multi-level ecological network(MEN)framework to resolve the tension between urban expansion and ecological integrity.By integrating the cost-weighted distance analysis with a hierarchical network transmission mechanism,we established a cross-scale spatial optimization system,which coordinated the regional ecological corridors and local habitat patches.Comparative experiments with conventional single-scale approaches and scenario simulations using the PLUS model show that the MEN framework had superior performance in three dimensions:(1)spatial governance:the primary-level network(peri-urban natural reserves)effectively contained urban sprawl,and the secondary-level network(intra-urban green corridors)mitigated habitat fragmentation and improved the built-environment;(2)scenario robustness:the model maintained an optimal compactness-loose balance in multiple development pathways;(3)landscape metrics:patch fragmentation decreased by 18.25%,and the internal landscape richness improved by 10.66%compared to the scenario without USM optimization.The findings provide new insight to establish a hierarchical ecological optimization framework as a nature-based spatial protocol to reconcile metropolitan growth with landscape sustainability.展开更多
Compared to the traditional cast-in-situ technique,the novel prefabricated underground structure(PUS)employs machinery excavation and assembly.Notably,the PUS assembly system undergoes multi-level force transmission t...Compared to the traditional cast-in-situ technique,the novel prefabricated underground structure(PUS)employs machinery excavation and assembly.Notably,the PUS assembly system undergoes multi-level force transmission through soil,structure,component,and joint interactions.This transmission mechanism remains inadequately understood,consequently posing frequent instability risks during PUS construction.Hereby,this study foremost addresses this problem for multi-level information modeling and planning for PUS under joint principal control.Three modules of numerical modeling,design theory and adaptive planning were constructed and integrated into the Soil-structure-component-joint Adaptive Planning Model(SAPM).Through a real-project application of SAPM,key insights are as follows:(1)SAPM achieves multi-level information adaptivity by planning the joint properties,which mitigates the soil-structure interaction effect of main and secondary structures by 18% and 63%,respectively.(2)Different joints and components may not achieve optimum solutions with uniform joint properties.Top,bottom and midslab joints achieve multi-level information adaptivity only when their respective joint stiffness factors are 0.90,0.61 and 0.65.(3)The use of semi-rigid joints in PUS has multiple advantages over the common cast-in-situ rigid joints.The semi-rigid scheme reduces ring assembly time and cost by approximately 40%and 20%,respectively,compared to hinged and rigid joint schemes.The research results provide a theoretical and instrumental basis for the safe construction of PUS in complex urban and geotechnical environments.展开更多
The digital transformation of territorial spatial planning has underscored the urgent need to integrate ecological network into spatial planning practices.In response,we developed two innovative new tools,the Ecologic...The digital transformation of territorial spatial planning has underscored the urgent need to integrate ecological network into spatial planning practices.In response,we developed two innovative new tools,the Ecological Linkage Tool(ELT)and the Relative Spatial Conflict Index(RSCI),to enhance ecological networks applications by addressing spatial conflicts and structural resilience.The ELT identified ecological corridors within and outside irregular ecological sources,activation points,and stepping stones in parallel,and then constructed an intact ecological network.By integrating the RSCI and complex network metrics,the spatial conflicts and structural resilience were evaluated.The framework was implemented in the Hohhot-Baotou-Ordos-Yulin(HBOY)urban agglomeration,identifying a total of 5,814 corridors,of which 67%were classified as intra-patch and 33%as inter-patch.The number and distribution of these corridors were determined by the size and shape of the ecological sources,and the connectivity of intra-patch corridors was 34%higher than inter-patch corridors.According to the RSCI,60%of the corridors experienced spatial conflicts,with 21%involving production spaces or composite production-related conflicts.Moreover,Yulin served as a key hub in the ecological network,and Baotou had the highest network efficiency.Compound conflict corridors(involving production,living,and open spaces)had a greater impact on overall ecological network efficiency compared to those with single or dual conflicts.Meanwhile,the failure of 40%of corridors without spatial conflicts would directly result in a 96.9%decline in network efficiency,highlighting their critical role in maintaining network functionality.This study provides an enhanced ecological network application solution for the China Spatial Planning Observation Network(CSPON),supporting spatial planning practices.展开更多
The combinations of machine learning with ab initio methods have attracted much attention for their potential to resolve the accuracy-efficiency dilemma and facilitate calculations for large-scale systems.Recently,equ...The combinations of machine learning with ab initio methods have attracted much attention for their potential to resolve the accuracy-efficiency dilemma and facilitate calculations for large-scale systems.Recently,equivariant message passing neural networks(MPNNs)that explicitly incorporate symmetry constraints have demonstrated promise for interatomic potential and density functional theory(DFT)Hamiltonian predictions.However,the high-order tensors used to represent node and edge information are coupled through the Clebsch–Gordan tensor product,leading to steep increases in computational complexity and seriously hindering the performance of equivariant MPNNs.Here,we develop high-order tensor machine-learning Hamiltonian(Hot-Ham),an E(3)equivariant MPNN framework that combines two advanced technologies:local coordinate transformation and Gaunt tensor product to efficiently model DFT Hamiltonians.These two innovations significantly reduce the complexity of tensor products from O(L6)to O(L3)or O(L2log2L)for the max tensor order L,and enhance the performance of MPNNs.Benchmarks on several public datasets demonstrate its state-of-the-art accuracy with relatively few parameters,and applications to multilayer twisted moire systems,heterostructures,and allotropes showcase its generalization ability and high efficiency.Our Hot-Ham method provides a new perspective for developing efficient equivariant neural networks and would be a promising approach for investigating the electronic properties of large-scale materials systems.展开更多
A dual‑task parallel machine learning framework was developed by integrating a convolutional autoencoder(CAE)and a fully connected neural network(FCNN)via the gradient‑coupled mechanism,enabling simultaneous data comp...A dual‑task parallel machine learning framework was developed by integrating a convolutional autoencoder(CAE)and a fully connected neural network(FCNN)via the gradient‑coupled mechanism,enabling simultaneous data compression‑reconstruction and structural damage identification.Under the condition where 40% of the sensor nodes are missing,the model successfully reconstructs the full sensor network with an R2 of 0.916 and normalized root mean square error(NRMSE)of 0.0288.Even under significant noise contamination with an SNR of 12 dB,the model maintains strong reconstruction performance,achieving a R2 of 0.910 and NRMSE of 0.0253.Forty‑six structural damage scenarios were simulated using the scaled bridge model.The accuracy of spatial localization and quantification of the damage severity using the framework exceeds 99.3%.The proposed framework reduces the training time by 54.4%and iteration counts by 45.5% compared to conventional two‑stage machine learning approaches,demonstrating the efficiency of gradient‑coupled optimization.展开更多
The performance of polymer networks is directly determined by their structure.Understanding the network structure offers insights into optimizing material performance,such as elasticity,toughness,and swelling behavior...The performance of polymer networks is directly determined by their structure.Understanding the network structure offers insights into optimizing material performance,such as elasticity,toughness,and swelling behavior.Herein,in this study we introduce the Dijkstra algorithm from graph theory to characterize polymer networks based on star-shaped multi-armed precursors by employing coarse-grained molecular dynamics simulations coupled with stochastic reaction model.Our research focuses on the structure characteristics of the generated networks,including the number and size of loops,as well as network dispersity characterized by loops.Tracking the number of loops during network generation allows for the identification of the gel point.The size distribution of loops in the network is primarily related to the functionality of the precursors,and the system with fewer precursor arms exhibiting larger average loop sizes.Strain-stress curves indicate that materials with identical functionality and precursor arm lengths generally exhibit superior performance.This method of characterizing network structures helps to refine microscopic structural analysis and contributes to the enhancement and optimization of material properties.展开更多
Existing imaging techniques cannot simultaneously achieve high resolution and a wide field of view,and manual multi-mineral segmentation in shale lacks precision.To address these limitations,we propose a comprehensive...Existing imaging techniques cannot simultaneously achieve high resolution and a wide field of view,and manual multi-mineral segmentation in shale lacks precision.To address these limitations,we propose a comprehensive framework based on generative adversarial network(GAN)for characterizing pore structure properties of shale,which incorporates image augmentation,super-resolution reconstruction,and multi-mineral auto-segmentation.Using real 2D and 3D shale images,the framework was assessed through correlation function,entropy,porosity,pore size distribution,and permeability.The application results show that this framework enables the enhancement of 3D low-resolution digital cores by a scale factor of 8,without paired shale images,effectively reconstructing the unresolved fine-scale pores under a low resolution,rather than merely denoising,deblurring,and edge clarification.The trained GAN-based segmentation model effectively improves manual multi-mineral segmentation results,resulting in a strong resemblance to real samples in terms of pore size distribution and permeability.This framework significantly improves the characterization of complex shale microstructures and can be expanded to other heterogeneous porous media,such as carbonate,coal,and tight sandstone reservoirs.展开更多
To assess the high-temperature creep properties of titanium matrix composites for aircraft skin,the TA15 alloy,TiB/TA15 and TiB/(TA15−Si)composites with network structure were fabricated using low-energy milling and v...To assess the high-temperature creep properties of titanium matrix composites for aircraft skin,the TA15 alloy,TiB/TA15 and TiB/(TA15−Si)composites with network structure were fabricated using low-energy milling and vacuum hot pressing sintering techniques.The results show that introducing TiB and Si can reduce the steady-state creep rate by an order of magnitude at 600℃ compared to the alloy.However,the beneficial effect of Si can be maintained at 700℃ while the positive effect of TiB gradually diminishes due to the pores near TiB and interface debonding.The creep deformation mechanism of the as-sintered TiB/(TA15−Si)composite is primarily governed by dislocation climbing.The high creep resistance at 600℃ can be mainly attributed to the absence of grain boundaryαphases,load transfer by TiB whisker,and the hindrance of dislocation movement by silicides.The low steady-state creep rate at 700℃ is mainly resulted from the elimination of grain boundaryαphases as well as increased dynamic precipitation of silicides andα2.展开更多
Background Post-stroke depression(PSD)is a common neuropsychiatric problem associated with a high disease burden and reduced quality of life(QoL).To date,few studies have examined the network structure of depressive s...Background Post-stroke depression(PSD)is a common neuropsychiatric problem associated with a high disease burden and reduced quality of life(QoL).To date,few studies have examined the network structure of depressive symptoms and their relationships with QoL in stroke survivors.Aims This study aimed to explore the network structure of depressive symptoms in PSD and investigate the interrelationships between specific depressive symptoms and QoL among older stroke survivors.Methods This study was based on the 2017–2018 collection of data from a large national survey in China.Depressive symptoms were assessed using the 10-item Centre for Epidemiological Studies Depression Scale(CESD),while QoL was measured with the World Health Organization Quality of Life-brief version.Network analysis was employed to explore the structure of PSD,using expected influence(EI)to identify the most central symptoms and the flow function to investigate the association between depressive symptoms and QoL.Results A total of 1123 stroke survivors were included,with an overall prevalence of depression of 34.3%(n=385;95%confidence interval 31.5%to 37.2%).In the network model of depression,the most central symptoms were CESD3(‘feeling blue/depressed’,EI:1.180),CESD6(‘feeling nervous/fearful’,EI:0.864)and CESD8(‘loneliness’,EI:0.843).In addition,CESD5(‘hopelessness’,EI:−0.195),CESD10(‘sleep disturbances’,EI:−0.169)and CESD4(‘everything was an effort’,EI:−0.150)had strong negative associations with QoL.Conclusion This study found that PSD was common among older Chinese stroke survivors.Given its negative impact on QoL,appropriate interventions targeting central symptoms and those associated with QoL should be developed and implemented for stroke survivors with PSD.展开更多
基金National Science and Technology Major Project of the People's Republic of China,No.SQ2026AAA090540。
摘要In the context of global change,a central challenge in ecology is to establish the multi-scale evolution and coupling mechanisms of ecosystems.In particular,it is necessary to clarify the structural mismatch between hierarchical levels that arises when ecological networks(ENs)are constructed across varying extents or grains.Using city-and central urban-level examples,we introduced a cross-level ENs spatial mismatch measurement index(SMI)and a scale-effect analysis framework.Five representative cities from the Northeast,Northwest,Central,Southwest,and Southeast China were selected as research areas.A unified approach combining minimum cumulative resistance and XGBoost models enable the preliminary construction of two-level ENs.SMI is then applied to evaluate cross-level mismatches,followed by analysis of extent and grain effects.Mechanisms underlying EN disconnection and potential solution pathways are further examined.The results show that:(1)spatial mismatch indicators(SMI_source,SMI_corridor,SMI_nodes)defined on ecological source areas(ESA),corridor,and strategic nodes,reflect mismatch degrees across EN levels;(2)scale effects reveal decreasing SMI with expanding observation extent in central urban area,fluctuating values with synchronous change in data grain,and increasing values with higher statistical grid density;(3)the largest patch index and landscape division index exert a strong influence on SMI_source,while patch number and Shannon's diversity index play key roles in SMI_corridor;and(4)variation in landscape composition and configuration heterogeneity across scales provides explanatory power of mismatch phenomenon and scale effects.The study contributes to ecological pattern analysis by offering a quantitative method for multi-scale EN research,with implications for ecological protection and regional landscape planning.
基金Project supported by the National Natural Science Foundation of China(No.52250287)。
摘要Multilayer structures composed of quasi-zero-stiffness(QZS)units exhibit mechanical characteristics distinct from those of a single unit,and their behaviors are governed by the coupling mechanism between the QZS units.This paper introduces the coupling coefficient to quantitatively describe this mechanism,classifying the system into strongly coupled and weakly coupled states.Through theoretical analysis,numerical simulation,and experimental testing,the static and dynamic responses under different coupling states are comparatively investigated.The results show that in the strongly coupled system,the deformation behavior of each QZS unit shows high consistency,leading to a wider QZS region,weaker nonlinear characteristics,and stronger dynamic response.In the weakly coupled systems,the low degree of deformation coordinations among the units results in different QZS regions,enabling low-frequency vibration isolation under varying loads.The analytical approach of the coupling mechanisms and the static and dynamic response behaviors generated by the two coupling mechanisms provide guidance for the structural design of multifunctional and highly adaptable multi-level QZS metamaterials.
基金supported by grants from the National Natural Science Foundation of China(52538010)the Guangzhou Municipal Education Bureau’s Scientific Research Project,China(2024312217)The financial support is gratefully acknowledged.
摘要In structural optimization,data-driven surrogate models are often explored as alternatives to finite element analysis to reduce computational cost.However,conventional neural networks usually fail to capture key structural characteristics and are limited to predicting global responses(e.g.,top displacement),but usually fail to achieve accurate internal force predictions with conventional training data volumes.As a result,most existing studies involving surrogate models did not concern internal force constraints.To address this issue,this study proposes a structural optimization framework based on a pre-trained Physics-Informed Neural Network(PINN)surrogate model.By embedding static equilibrium equation into the loss function,the model achieves higher predictive accuracy,particularly for internal forces,while pre-training accelerates convergence and enhances stability.Combined with an improved multi-swarm particle swarm optimization(MPSO)algorithm,the framework enables efficient optimization of multi-story frame structures under internal force and multiple other constraints.The application to a six-story frame structure validates its effectiveness:compared with a DNN-based model,the PINN-based model improves the coefficient of determination for internal force prediction from 0.8874 to 0.9937.These results demonstrate that the proposed method offers a promising approach for efficient optimization of multi-story frame structures.
基金supported by the National Natural Science Foundation of China(Grant Nos.52130805,52379106)Qingdao Guoxin Jiaozhou Bay Second Submarine Tunnel Co.,Ltd.(Grant No.kh0023020222333).
摘要Evaluation of compressive strength in underground lining structures is critical for ensuring structural integrity and safety.Traditional assessment methods are often destructive,time-consuming,and impractical in confined environments such as tunnels and utility corridors.This study introduces an automated,nondestructive approach to visualize and estimate the compressive strength of underground concrete lining using hyperspectral imaging(HSI)combined with deep neural network(DNN)models.High-dimensional spectral data of concrete lining are assembled and trained to develop two DNN-based regression models,namely the Mono-Spectrum Deep Neural Regressor(MS-DNR)and the Segmented-Spectrum Deep Neural Regressor(SegS_DNR).Utilizing the SegS_DNR model,two-dimensional(2D)compressive strength distribution heatmaps were generated for visualization and assessment of strength variations.The SegS_DNR model demonstrated excellent predictive performance,achieving a coefficient of determination(Rp²)of 0.925 and a Residual Prediction Deviation(RPD)of 5.28 on the testing set for compressive strength estimation.The idea is further validated in site by investigating the capability of identifying the defect regions of the tunnel concrete lining,namely the cracked,spalling,and leaking areas,and demonstrated promising performance in comparison with experienced inspectors on site.This approach offers a contact-free technique for automated structural health monitoring,contributing to safer and more sustainable underground maintenance practices.
基金supported by the Brain Science and Brain-like Intelligence Technology National Science and Technology Major Project(2022ZD0211600)Hospital affiliated to Southeast University,Jiangsu Province High-Level Hospital Construction Funds(GSP-LCYJFH07)+1 种基金Natural Science Foundation of Jiangsu Province(BK20180379)China Postdoctoral Science Foundation(2023M742440)。
摘要Cerebral small vessel disease(CSVD)encompasses a spectrum of pathological processes that affect the small arteries,capillaries,and venules of the brain.The neuroimaging features include white matter hyperintensities(WMH),lacunar infarcts,cerebral microbleeds,and enlarged perivascular spaces.
基金the financial support provided by the National Natural Science Foundation of China(grant no.22373032)the open research fund of Songshan Lake Materials Laboratory(grant no.2023SLABFK06)。
摘要With the rapid growth of technologies requiring high-power energy storage,achieving long-term cyclic stability under ultra-high current density is a key challenge.Aqueous zinc-ion batteries(AZIBs)are promising candidates due to their intrinsic safety and low cost,but they suffer from severe interfacial instability at rates exceeding 10 mA cm-2,which drastically shortens their cycle life.Inspired by theoretical calculations,triglyme(TGDE)additive with strong electron-donating groups into Zn(OTf)2 electrolytes effectively disrupts the hydrogen-bond network among free water molecules,while the weak coordination of TGDE with Zn2+promotes the entry of OTf-into the primary Zn2+solvated sheath,thus decreasing the coordination number of water with Zn2+.As such,the hydrogen-bond network and the bulk solvated structure are reconstructed with better stability.Moreover,the strong adsorption of TGDE lying on the Zn(002)surface would induce Zn depositions along(002)together with the reduced exposed surface,further effectively inhibiting side reactions.Likewise,TGDE electrolyte induces the formation of such ZnF2-ZnS dual-layer solid electrolyte interface(SEI)with superior chemical stability and ionic conductivity,thereby regulating Zn2+flux with dendrite-free depositions.Based on this electrolyte,Zn‖Zn cells can be stably cycled for 1300 h at a limit of 10 mA cm-2 and 10 mAh cm-2.The assembled Zn‖V2O5 full cells still maintain 99.9%capacity retention after 1000 cycles at 10 A g-1.This work provides a feasible approach for designing aqueous electrolytes to reconstruct the hydrogen-bond network and solvated structure,which can be extended to the applications of high-rate and high-temperature scenarios.
基金financially supported by the National Natural Science Foundation of China(No.52103127)the Opening Project of the State Key Laboratory of Polymer Materials Engineering(Sichuan University)(No.sklpme2022-4-10)Shaanxi Provincial Science and Technology Department(No.2025GH-YBXM-042).
摘要In this study,an architecture featuring a gradient conductive network structure and three-dimensional dual-continuous network structure is constructed in a carbon nanotubes/cellulose-boron nitride/poly(vinyl alcohol)(CNT/cellulose-BN/PVA)composite.Using cellulose aerogel as a template,CNT were incorporated into the cellulose template by vertically impregnating the CNT suspension.Following the impregnation of BN/PVA and high-pressure compression,three-dimensional dual-continuous network structure was successfully constructed in the CNT/cellulose-BN/PVA composite.The comprehensive performance of the composite,including electromagnetic interference(EMI)shielding and Joule heating performance,was investigated.The results indicate that the total EMI shielding effectiveness(SE)for the CNT/cellulose-BN/PVA composite reveals similar values for electromagnetic waves incident from different directions,but totally different shielding mechanisms.For the CNT/cellulose-BN/PVA composite with three impregnation cycles of CNT,the EMI SE values exceeded 39 dB for electromagnetic waves incident from both the high-and low-CNT-content sides.93%of the microwaves were reflected when electromagnetic waves were incident from the high-CNT-content side,while the reflection coefficient decreased to 0.44 for the transverse direction.In addition,the construction of the dual-continuous network structure enabled the composite to exhibit both excellent electrical conductivity and good thermal conductivity simultaneously,endowing the material with good Joule heating performance.CNT/cellulose-BN/PVA composite films have significant potential for application as EMI shielding materials in extremely cold weather.
基金supported in part by the General Program of the National Natural Science Foundation of China(62575116)the Open Project of the Text Computing and Cognitive Intelligence Ministry of Education Engineering Research Center(TCCI250208)the Fundamental Research Funds for the Central Universities(2024JYCXJJ062)。
摘要Graph neural networks(GNNs)often suffer from performance degradation due to the incompleteness of node features and structure relationships in the real world.Recently emerged graph completion learning(GCL)enhances the generalization of GNNs by reconstructing the missing node features or structure relationships.Nevertheless,these proposed GCL methods are supervised by a large number of labeled nodes,which limits their applications in extremely limited labeled nodes.Moreover,the existing GCL methods either focus on feature missing or structure missing tasks,and little effort was paid to more challenging scenarios where both node features and structure relationships are simultaneously missing.In this paper,a general GCL framework with the aid of multi-level contrast graph mask autoencoders(EWS-RGCN)is proposed to improve the generalization of GNNs guided by extremely weak supervision on graphs with features and structure missing.Specifically,to alleviate the mutual interference between missing node features and structure relationships caused by message passing of GNNs,we separate the feature and structure completion into two channels.Then,a multi-level contrastive loss is introduced to simultaneously maximize the mutual information between nodes from the encoding and decoding stage,which can discover more effective supervision information from the data itself for EWS-RGCN optimization,apart from label information.To further enhance the space consistency between reconstructed node features and structure relationships,the inter-channel information cooperation module is introduced to enhance the mutual learning of feature and structure completion channels.Extensive experiments on six benchmarks demonstrate the effectiveness of our EWS-RGCN.
基金supported by the National Natural Science Foundation of China(Nos.12422207 and 12372199).
摘要An efficient data-driven numerical framework is developed for transient heat conduction analysis in thin-walled structures.The proposed approach integrates spectral time discretization with neural network approximation,forming a spectral-integrated neural network(SINN)scheme tailored for problems characterized by long-time evolution.Temporal derivatives are treated through a spectral integration strategy based on orthogonal polynomial expansions,which significantly alleviates stability constraints associated with conventional time-marching schemes.A fully connected neural network is employed to approximate the temperature-related variables,while governing equa-tions and boundary conditions are enforced through a physics-informed loss formulation.Numerical investigations demonstrate that the proposed method maintains high accuracy even when large time steps are adopted,where standard numerical solvers often suffer from instability or excessive computational cost.Moreover,the framework exhibits strong robustness for ultrathin configurations with extreme aspect ratios,achieving relative errors on the order of 10−5 or lower.These results indicate that the SINN framework provides a reliable and efficient alternative for transient thermal analysis of thin-walled structures under challenging computational conditions.
基金Project supported by the National Natural Science Foun-dation of China(Grant No.62373197)the Natural Science Foundation of the Higher Education Institutions of Jiangsu Province,China(Grant No.23KJB120010)+1 种基金the Industry-University-Research Cooperation Project of Jiangsu Province,China(Grant No.BY20251038)the Cultivation and In-cubation Project of the College of Automation,Nanjing Uni-versity of Posts and Telecommunications.
摘要Multilayer complex dynamical networks,characterized by the intricate topological connections and diverse hierarchical structures,present significant challenges in determining complete structural configurations due to the unique functional attributes and interaction patterns inherent to different layers.This paper addresses the critical question of whether structural information from a known layer can be used to reconstruct the unknown intralayer structure of a target layer within general weighted output-coupling multilayer networks.Building upon the generalized synchronization principle,we propose an innovative reconstruction method that incorporates two essential components in the design of structure observers,the cross-layer coupling modulator and the structural divergence term.A key advantage of the proposed reconstruction method lies in its flexibility to freely designate both the unknown target layer and the known reference layer from the general weighted output-coupling multilayer network.The reduced dependency on full-state observability enables more deployment in engineering applications with partial measurements.Numerical simulations are conducted to validate the effectiveness of the proposed structure reconstruction method.
基金supported by the National Natural Science Foundation of China(No.12472202).
摘要Machine learning provides a fast and accurate tool for the prediction of a physical model.In this paper,a machine learning framework based on the physics-informed neural network(PINN)was established to predict the linear elastic static deformation of plate and shell structures.In contrast to the purely data-driven neural network,PINN incorporates the physical laws into the training process,thus reducing the required amount of data.The loss functions of the PINN are constructed based on the total potential energy functions of the thin-walled structure.Besides,the proposed PINN can be easily extended to shell structures with multiple patches by adding interface compatibility constraints into the loss function.The performance of the PINNs with the energy-based loss functions was evaluated with different shell structures and compared with the finite element results.Numerical examples show that the highly accurate results can be achieved based on the proposed framework which significantly reduces the amount of required training data compared to the data-driven neural network.
基金National Key Research and Development Program of China,No.2019YFD1101304National Natural Science Foundation of China,No.52278059+1 种基金Natural Science Foundation of Hunan Province of China,No.2024JJ8316Hunan Provincial Innovation Foundation For Postgraduate,No.CX20250634。
摘要Urban spatial morphology(USM)optimization is critical to balancing biodiversity conservation and sustainable urbanization.However,previous studies predominantly focused on the socio-economic efficiency and static ecological metrics and rarely addressed the dynamic USM optimization across spatial scales.Here,we developed a multi-level ecological network(MEN)framework to resolve the tension between urban expansion and ecological integrity.By integrating the cost-weighted distance analysis with a hierarchical network transmission mechanism,we established a cross-scale spatial optimization system,which coordinated the regional ecological corridors and local habitat patches.Comparative experiments with conventional single-scale approaches and scenario simulations using the PLUS model show that the MEN framework had superior performance in three dimensions:(1)spatial governance:the primary-level network(peri-urban natural reserves)effectively contained urban sprawl,and the secondary-level network(intra-urban green corridors)mitigated habitat fragmentation and improved the built-environment;(2)scenario robustness:the model maintained an optimal compactness-loose balance in multiple development pathways;(3)landscape metrics:patch fragmentation decreased by 18.25%,and the internal landscape richness improved by 10.66%compared to the scenario without USM optimization.The findings provide new insight to establish a hierarchical ecological optimization framework as a nature-based spatial protocol to reconcile metropolitan growth with landscape sustainability.
基金supported by the Natural Science Foundation of China and Guangdong(Grant Nos.52308410,52478405,and 2025A1515010979).
摘要Compared to the traditional cast-in-situ technique,the novel prefabricated underground structure(PUS)employs machinery excavation and assembly.Notably,the PUS assembly system undergoes multi-level force transmission through soil,structure,component,and joint interactions.This transmission mechanism remains inadequately understood,consequently posing frequent instability risks during PUS construction.Hereby,this study foremost addresses this problem for multi-level information modeling and planning for PUS under joint principal control.Three modules of numerical modeling,design theory and adaptive planning were constructed and integrated into the Soil-structure-component-joint Adaptive Planning Model(SAPM).Through a real-project application of SAPM,key insights are as follows:(1)SAPM achieves multi-level information adaptivity by planning the joint properties,which mitigates the soil-structure interaction effect of main and secondary structures by 18% and 63%,respectively.(2)Different joints and components may not achieve optimum solutions with uniform joint properties.Top,bottom and midslab joints achieve multi-level information adaptivity only when their respective joint stiffness factors are 0.90,0.61 and 0.65.(3)The use of semi-rigid joints in PUS has multiple advantages over the common cast-in-situ rigid joints.The semi-rigid scheme reduces ring assembly time and cost by approximately 40%and 20%,respectively,compared to hinged and rigid joint schemes.The research results provide a theoretical and instrumental basis for the safe construction of PUS in complex urban and geotechnical environments.
基金funded by the National Key Research and Devel-opment Program of China(Grant No.2022YFC3800802).
摘要The digital transformation of territorial spatial planning has underscored the urgent need to integrate ecological network into spatial planning practices.In response,we developed two innovative new tools,the Ecological Linkage Tool(ELT)and the Relative Spatial Conflict Index(RSCI),to enhance ecological networks applications by addressing spatial conflicts and structural resilience.The ELT identified ecological corridors within and outside irregular ecological sources,activation points,and stepping stones in parallel,and then constructed an intact ecological network.By integrating the RSCI and complex network metrics,the spatial conflicts and structural resilience were evaluated.The framework was implemented in the Hohhot-Baotou-Ordos-Yulin(HBOY)urban agglomeration,identifying a total of 5,814 corridors,of which 67%were classified as intra-patch and 33%as inter-patch.The number and distribution of these corridors were determined by the size and shape of the ecological sources,and the connectivity of intra-patch corridors was 34%higher than inter-patch corridors.According to the RSCI,60%of the corridors experienced spatial conflicts,with 21%involving production spaces or composite production-related conflicts.Moreover,Yulin served as a key hub in the ecological network,and Baotou had the highest network efficiency.Compound conflict corridors(involving production,living,and open spaces)had a greater impact on overall ecological network efficiency compared to those with single or dual conflicts.Meanwhile,the failure of 40%of corridors without spatial conflicts would directly result in a 96.9%decline in network efficiency,highlighting their critical role in maintaining network functionality.This study provides an enhanced ecological network application solution for the China Spatial Planning Observation Network(CSPON),supporting spatial planning practices.
基金supported by the National Natural Science Foundation of China(Grant Nos.12125404,T2495231,and 123B2049)the Basic Research Program of Jiangsu(Grant Nos.BK20233001,BK20241253,and BK20253009)+3 种基金the Jiangsu Funding Program for Excellent Postdoctoral Talent(Grant Nos.2024ZB002 and 2024ZB075)the Postdoctoral Fellowship Program of CPSF(Grant No.GZC20240695)the AI&AI for Science program of Nanjing University,the Artificial Intelligence and Quantum physics(AIQ)program of Nanjing Universitythe Fundamental Research Funds for the Central Universities。
摘要The combinations of machine learning with ab initio methods have attracted much attention for their potential to resolve the accuracy-efficiency dilemma and facilitate calculations for large-scale systems.Recently,equivariant message passing neural networks(MPNNs)that explicitly incorporate symmetry constraints have demonstrated promise for interatomic potential and density functional theory(DFT)Hamiltonian predictions.However,the high-order tensors used to represent node and edge information are coupled through the Clebsch–Gordan tensor product,leading to steep increases in computational complexity and seriously hindering the performance of equivariant MPNNs.Here,we develop high-order tensor machine-learning Hamiltonian(Hot-Ham),an E(3)equivariant MPNN framework that combines two advanced technologies:local coordinate transformation and Gaunt tensor product to efficiently model DFT Hamiltonians.These two innovations significantly reduce the complexity of tensor products from O(L6)to O(L3)or O(L2log2L)for the max tensor order L,and enhance the performance of MPNNs.Benchmarks on several public datasets demonstrate its state-of-the-art accuracy with relatively few parameters,and applications to multilayer twisted moire systems,heterostructures,and allotropes showcase its generalization ability and high efficiency.Our Hot-Ham method provides a new perspective for developing efficient equivariant neural networks and would be a promising approach for investigating the electronic properties of large-scale materials systems.
基金The National Natural Science Foundation of China(No.52361165658,U24A20169).
摘要A dual‑task parallel machine learning framework was developed by integrating a convolutional autoencoder(CAE)and a fully connected neural network(FCNN)via the gradient‑coupled mechanism,enabling simultaneous data compression‑reconstruction and structural damage identification.Under the condition where 40% of the sensor nodes are missing,the model successfully reconstructs the full sensor network with an R2 of 0.916 and normalized root mean square error(NRMSE)of 0.0288.Even under significant noise contamination with an SNR of 12 dB,the model maintains strong reconstruction performance,achieving a R2 of 0.910 and NRMSE of 0.0253.Forty‑six structural damage scenarios were simulated using the scaled bridge model.The accuracy of spatial localization and quantification of the damage severity using the framework exceeds 99.3%.The proposed framework reduces the training time by 54.4%and iteration counts by 45.5% compared to conventional two‑stage machine learning approaches,demonstrating the efficiency of gradient‑coupled optimization.
基金supported by the National Natural Science Foundation of China(No.22373024,22463006,and 52463015)the joint fund between the Gansu Provincial Science and Technology Plan Project(Natural Science Foundation)(No.23JRRA794)the Open Research Fund of the Songshan Lake Materials Laboratory(No.2023SLABFK11)。
摘要The performance of polymer networks is directly determined by their structure.Understanding the network structure offers insights into optimizing material performance,such as elasticity,toughness,and swelling behavior.Herein,in this study we introduce the Dijkstra algorithm from graph theory to characterize polymer networks based on star-shaped multi-armed precursors by employing coarse-grained molecular dynamics simulations coupled with stochastic reaction model.Our research focuses on the structure characteristics of the generated networks,including the number and size of loops,as well as network dispersity characterized by loops.Tracking the number of loops during network generation allows for the identification of the gel point.The size distribution of loops in the network is primarily related to the functionality of the precursors,and the system with fewer precursor arms exhibiting larger average loop sizes.Strain-stress curves indicate that materials with identical functionality and precursor arm lengths generally exhibit superior performance.This method of characterizing network structures helps to refine microscopic structural analysis and contributes to the enhancement and optimization of material properties.
基金Supported by the National Natural Science Foundation of China(U23A20595,52034010,52288101)National Key Research and Development Program of China(2022YFE0203400)+1 种基金Shandong Provincial Natural Science Foundation(ZR2024ZD17)Fundamental Research Funds for the Central Universities(23CX10004A).
摘要Existing imaging techniques cannot simultaneously achieve high resolution and a wide field of view,and manual multi-mineral segmentation in shale lacks precision.To address these limitations,we propose a comprehensive framework based on generative adversarial network(GAN)for characterizing pore structure properties of shale,which incorporates image augmentation,super-resolution reconstruction,and multi-mineral auto-segmentation.Using real 2D and 3D shale images,the framework was assessed through correlation function,entropy,porosity,pore size distribution,and permeability.The application results show that this framework enables the enhancement of 3D low-resolution digital cores by a scale factor of 8,without paired shale images,effectively reconstructing the unresolved fine-scale pores under a low resolution,rather than merely denoising,deblurring,and edge clarification.The trained GAN-based segmentation model effectively improves manual multi-mineral segmentation results,resulting in a strong resemblance to real samples in terms of pore size distribution and permeability.This framework significantly improves the characterization of complex shale microstructures and can be expanded to other heterogeneous porous media,such as carbonate,coal,and tight sandstone reservoirs.
基金financially supported by the National Key R&D Program of China(No.2022YFB3707405)the National Natural Science Foundation of China(Nos.U22A20113,52171137,52071116)+1 种基金Heilongjiang Provincial Natural Science Foundation,China(No.TD2020E001)Heilongjiang Touyan Team Program,China.
摘要To assess the high-temperature creep properties of titanium matrix composites for aircraft skin,the TA15 alloy,TiB/TA15 and TiB/(TA15−Si)composites with network structure were fabricated using low-energy milling and vacuum hot pressing sintering techniques.The results show that introducing TiB and Si can reduce the steady-state creep rate by an order of magnitude at 600℃ compared to the alloy.However,the beneficial effect of Si can be maintained at 700℃ while the positive effect of TiB gradually diminishes due to the pores near TiB and interface debonding.The creep deformation mechanism of the as-sintered TiB/(TA15−Si)composite is primarily governed by dislocation climbing.The high creep resistance at 600℃ can be mainly attributed to the absence of grain boundaryαphases,load transfer by TiB whisker,and the hindrance of dislocation movement by silicides.The low steady-state creep rate at 700℃ is mainly resulted from the elimination of grain boundaryαphases as well as increased dynamic precipitation of silicides andα2.
基金supported by Beijing High Level Public Health Technology Talent Construction Project(Discipline Backbone-01-028)the Beijing Municipal Science&Technology Commission(No.Z181100001518005)+2 种基金the Capital's Funds for Health Improvement and Research(CFH 2024-2-1174)the University of Macao(MYRG-GRG2023-00141-FHS,CPG2025-00021-FHS)the Science and Technology Plan Foundation of Guangzhou(No.202201011663).
摘要Background Post-stroke depression(PSD)is a common neuropsychiatric problem associated with a high disease burden and reduced quality of life(QoL).To date,few studies have examined the network structure of depressive symptoms and their relationships with QoL in stroke survivors.Aims This study aimed to explore the network structure of depressive symptoms in PSD and investigate the interrelationships between specific depressive symptoms and QoL among older stroke survivors.Methods This study was based on the 2017–2018 collection of data from a large national survey in China.Depressive symptoms were assessed using the 10-item Centre for Epidemiological Studies Depression Scale(CESD),while QoL was measured with the World Health Organization Quality of Life-brief version.Network analysis was employed to explore the structure of PSD,using expected influence(EI)to identify the most central symptoms and the flow function to investigate the association between depressive symptoms and QoL.Results A total of 1123 stroke survivors were included,with an overall prevalence of depression of 34.3%(n=385;95%confidence interval 31.5%to 37.2%).In the network model of depression,the most central symptoms were CESD3(‘feeling blue/depressed’,EI:1.180),CESD6(‘feeling nervous/fearful’,EI:0.864)and CESD8(‘loneliness’,EI:0.843).In addition,CESD5(‘hopelessness’,EI:−0.195),CESD10(‘sleep disturbances’,EI:−0.169)and CESD4(‘everything was an effort’,EI:−0.150)had strong negative associations with QoL.Conclusion This study found that PSD was common among older Chinese stroke survivors.Given its negative impact on QoL,appropriate interventions targeting central symptoms and those associated with QoL should be developed and implemented for stroke survivors with PSD.