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Modeling of Precipitation over Africa:Progress,Challenges,and Prospects
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作者 A.A.AKINSANOLA C.N.WENHAJI +21 位作者 R.BARIMALALA P.-A.MONERIE R.D.DIXON A.T.TAMOFFO M.O.ADENIYI V.ONGOMA I.DIALLO M.GUDOSHAVA C.M.WAINWRIGHT R.JAMES K.C.SILVERIO A.FAYE S.S.NANGOMBE M.W.POKAM D.A.VONDOU N.C.G.HART I.PINTO M.KILAVI S.HAGOS E.N.RAJAGOPAL R.K.KOLLI S.JOSEPH 《Advances in Atmospheric Sciences》 2026年第1期59-86,共28页
In recent years,there has been an increasing need for climate information across diverse sectors of society.This demand has arisen from the necessity to adapt to and mitigate the impacts of climate variability and cha... In recent years,there has been an increasing need for climate information across diverse sectors of society.This demand has arisen from the necessity to adapt to and mitigate the impacts of climate variability and change.Likewise,this period has seen a significant increase in our understanding of the physical processes and mechanisms that drive precipitation and its variability across different regions of Africa.By leveraging a large volume of climate model outputs,numerous studies have investigated the model representation of African precipitation as well as underlying physical processes.These studies have assessed whether the physical processes are well depicted and whether the models are fit for informing mitigation and adaptation strategies.This paper provides a review of the progress in precipitation simulation overAfrica in state-of-the-science climate models and discusses the major issues and challenges that remain. 展开更多
关键词 RAINFALL MONSOON climate modeling CORDEX CMIP6 convection-permitting models
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Candida albicans and colorectal cancer:A paradoxical role revealed through metabolite profiling and prognostic modeling 被引量:2
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作者 Hao-Ling Zhang Rui Zhao +8 位作者 Di Wang Siti Nurfatimah Mohd Sapudin Badrul Hisham Yahaya Mohammad Syamsul Reza Harun Zhong-Wen Zhang Zhi-Jing Song Yan-Ting Liu Sandai Doblin Ping Lu 《World Journal of Clinical Oncology》 2025年第4期195-279,共85页
BACKGROUND Emerging evidence implicates Candida albicans(C.albicans)in human oncogenesis.Notably,studies have supported its involvement in regulating outcomes in colorectal cancer(CRC).This study investigated the para... BACKGROUND Emerging evidence implicates Candida albicans(C.albicans)in human oncogenesis.Notably,studies have supported its involvement in regulating outcomes in colorectal cancer(CRC).This study investigated the paradoxical role of C.albicans in CRC,aiming to determine whether it promotes or suppresses tumor development,with a focus on the mechanistic basis linked to its metabolic profile.AIM To investigate the dual role of C.albicans in the development and progression of CRC through metabolite profiling and to establish a prognostic model that integrates the microbial and metabolic interactions in CRC,providing insights into potential therapeutic strategies and clinical outcomes.METHODSA prognostic model integrating C. albicans with CRC was developed, incorporating enrichment analysis, immuneinfiltration profiling, survival analysis, Mendelian randomization, single-cell sequencing, and spatial transcriptomics.The effects of the C. albicans metabolite mixture on CRC cells were subsequently validated in vitro. Theprimary metabolite composition was characterized using liquid chromatography-mass spectrometry.RESULTSA prognostic model based on five specific mRNA markers, EHD4, LIME1, GADD45B, TIMP1, and FDFT1, wasestablished. The C. albicans metabolite mixture significantly reduced CRC cell viability. Post-treatment analysisrevealed a significant decrease in gene expression in HT29 cells, while the expression levels of TIMP1, EHD4, andGADD45B were significantly elevated in HCT116 cells. Conversely, LIME1 expression and that of other CRC celllines showed reductions. In normal colonic epithelial cells (NCM460), GADD45B, TIMP1, and FDFT1 expressionlevels were significantly increased, while LIME1 and EHD4 levels were markedly reduced. Following metabolitetreatment, the invasive and migratory capabilities of NCM460, HT29, and HCT116 cells were reduced. Quantitativeanalysis of extracellular ATP post-treatment showed a significant elevation (P < 0.01). The C. albicans metabolitemixture had no effect on reactive oxygen species accumulation in CRC cells but led to a reduction in mitochondrialmembrane potential, increased intracellular lipid peroxidation, and induced apoptosis. Metabolomic profilingrevealed significant alterations, with 516 metabolites upregulated and 531 downregulated.CONCLUSIONThis study introduced a novel prognostic model for CRC risk assessment. The findings suggested that the C.albicans metabolite mixture exerted an inhibitory effect on CRC initiation. 展开更多
关键词 Candida albicans Colorectal cancer Metabolic characteristics Extracellular ATP Prognostic model
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Face-Pedestrian Joint Feature Modeling with Cross-Category Dynamic Matching for Occlusion-Robust Multi-Object Tracking
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作者 Qin Hu Hongshan Kong 《Computers, Materials & Continua》 2026年第1期870-900,共31页
To address the issues of frequent identity switches(IDs)and degraded identification accuracy in multi object tracking(MOT)under complex occlusion scenarios,this study proposes an occlusion-robust tracking framework ba... To address the issues of frequent identity switches(IDs)and degraded identification accuracy in multi object tracking(MOT)under complex occlusion scenarios,this study proposes an occlusion-robust tracking framework based on face-pedestrian joint feature modeling.By constructing a joint tracking model centered on“intra-class independent tracking+cross-category dynamic binding”,designing a multi-modal matching metric with spatio-temporal and appearance constraints,and innovatively introducing a cross-category feature mutual verification mechanism and a dual matching strategy,this work effectively resolves performance degradation in traditional single-category tracking methods caused by short-term occlusion,cross-camera tracking,and crowded environments.Experiments on the Chokepoint_Face_Pedestrian_Track test set demonstrate that in complex scenes,the proposed method improves Face-Pedestrian Matching F1 area under the curve(F1 AUC)by approximately 4 to 43 percentage points compared to several traditional methods.The joint tracking model achieves overall performance metrics of IDF1:85.1825%and MOTA:86.5956%,representing improvements of 0.91 and 0.06 percentage points,respectively,over the baseline model.Ablation studies confirm the effectiveness of key modules such as the Intersection over Area(IoA)/Intersection over Union(IoU)joint metric and dynamic threshold adjustment,validating the significant role of the cross-category identity matching mechanism in enhancing tracking stability.Our_model shows a 16.7%frame per second(FPS)drop vs.fairness of detection and re-identification in multiple object tracking(FairMOT),with its cross-category binding module adding aboute 10%overhead,yet maintains near-real-time performance for essential face-pedestrian tracking at small resolutions. 展开更多
关键词 Cross-category dynamic binding joint feature modeling face-pedestrian association multi object tracking occlusion robustness
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A Nonspherical Cloud Scattering Database Using Aggregates of Roughened Bullet Rosettes Model for the Advanced Radiative Transfer Modeling System(ARMS) 被引量:1
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作者 Ziyue HUANG Hanyu LU +4 位作者 Ziqiang MA Yining SHI Yang HAN Hao HU Jun YANG 《Advances in Atmospheric Sciences》 2025年第7期1483-1498,共16页
Accurate satellite data assimilation under all-sky conditions requires enhanced parameterization of scattering properties for frozen hydrometeors in clouds.This study aims to develop a nonspherical scattering look-up ... Accurate satellite data assimilation under all-sky conditions requires enhanced parameterization of scattering properties for frozen hydrometeors in clouds.This study aims to develop a nonspherical scattering look-up table that contains the optical properties of five hydrometeor types—rain,cloud water,cloud ice,graupel,and snow—for the Advanced Radiative Transfer Modeling System(ARMS)at frequencies below 220 GHz.The discrete dipole approximation(DDA)method is employed to compute the single-scattering properties of solid cloud particles,modeling these particles as aggregated roughened bullet rosettes.The bulk optical properties of the cloud layer are derived by integrating the singlescattering properties with a modified Gamma size distribution,specifically for distributions with 18 effective radii.The bulk phase function is then projected onto a series of generalized spherical functions,applying the delta-M method for truncation.The results indicate that simulations using the newly developed nonspherical scattering look-up table exhibit significant consistency with observations under deep convection conditions.In contrast,assuming spherical solid cloud particles leads to excessive scattering at mid-frequency channels and insufficient scattering at high-frequency channels.This improvement in radiative transfer simulation accuracy for cloudy conditions will better support the assimilation of allsky microwave observations into numerical weather prediction models.·Frozen cloud particles were modeled as aggregates of bullet rosettes and the optical properties at microwave range were computed by DDA.·A complete process and technical details for constructing a look-up table of ARMS are provided.·The ARMS simulations generally show agreement with observations of MWTS and MWHS under typhoon conditions using the new look-up table. 展开更多
关键词 nonspherical particles scattering look-up table discrete dipole approximation Advanced Radiative Transfer modeling System
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Multiorgan-on-a-chip:an advanced platform for disease modeling,drug toxicity assessment,and therapeutic screening
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作者 Li Qiao Shiqi Chang +3 位作者 Lin Zou Feng Zhang Chang Cui Ningping Huang 《Bio-Design and Manufacturing》 2025年第6期1035-1062,I0043,共29页
Multiorgan-on-a-chip(MOoC)systems are advanced microfluidic devices that integrate multiple organ models into a single modular unit,each composed of cells derived from various tissues or organs.These systems enable in... Multiorgan-on-a-chip(MOoC)systems are advanced microfluidic devices that integrate multiple organ models into a single modular unit,each composed of cells derived from various tissues or organs.These systems enable interorgan communication and accurately replicate physiological conditions,providing a more physiologically relevant modeling framework for constructing disease models and predicting drug efficacy and toxicity.MOoC systems also provide significant advantages in terms of flexibility,cost-effectiveness,and reproducibility,making them valuable tools for drug development and toxicity assessment.In this review,we first provide an overview of the MOoC technology,covering cell sources,stimulations,materials and fabrication techniques,and biosensors.We then examine the application of MOoC systems in disease modeling,focusing on cancer metastasis,metabolic disorders,and cardiovascular disease.We next discuss the use of MOoC systems in drug toxicity evaluation and drug screening,emphasizing their role in providing comprehensive assessments of drug effects.Finally,we address the challenges it faces and the future perspectives of the MOoC technology. 展开更多
关键词 Multiorgan-on-a-chip Disease modeling Drug toxicity Drug screening
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Centrifuge modeling of contaminant transport in keyed sand-bentonite cutoff walls
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作者 Bo HUANG Linfeng CAO +2 位作者 Jiachen GUO Chunrui XU Yuchao LI 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 2025年第6期573-584,共12页
Sand-bentonite(SB)cutoff walls are commonly used as barriers in polluted areas.The embedded part of an SB wall in an aquitard is crucial for its performance.In this study,a centrifuge modeling test was carried out to ... Sand-bentonite(SB)cutoff walls are commonly used as barriers in polluted areas.The embedded part of an SB wall in an aquitard is crucial for its performance.In this study,a centrifuge modeling test was carried out to investigate the effect of contact between the key and the aquitard on the migration behavior of contaminants within an SB cutoff wall.The centrifuge was accelerated to 100g(gravitational acceleration)and maintained in-flight for 36 h,equivalent to 41 years of transport time in the prototype.Results showed that the contaminant concentration within the SB wall was higher downstream than in the middle in the thickness direction,and deeper regions exhibited a greater concentration than shallower ones.This concentration distribution indicated that contaminants were transported along the interface between the SB wall and the aquitard,bypassing the base of the SB wall to reach the downstream aquifer rapidly.An improved numerical simulation considering preferential interface migration was performed,which agreed with the centrifuge test results.The simulation results indicated that preferential interface migration,as a defect,significantly accelerated the speed of contaminant migration,reducing the breakthrough time of the SB wall to 1/9 of that without preferential interface migration. 展开更多
关键词 Cutoff wall Centrifuge modeling Contaminant transport DEFECT Breakthrough time
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Active learning-augmented end-to-end modeling toward fast inverse design in chirped pulse amplification
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作者 Helin Jiang Guoqing Pu +2 位作者 Xinyi Ma Weisheng Hu Lilin Yi 《Advanced Photonics Nexus》 2025年第4期154-162,共9页
To capture the nonlinear dynamics and gain evolution in chirped pulse amplification(CPA)systems,the split-step Fourier method and the fourth-order Runge–Kutta method are integrated to iteratively address the generali... To capture the nonlinear dynamics and gain evolution in chirped pulse amplification(CPA)systems,the split-step Fourier method and the fourth-order Runge–Kutta method are integrated to iteratively address the generalized nonlinear Schrödinger equation and the rate equations.However,this approach is burdened by substantial computational demands,resulting in significant time expenditures.In the context of intelligent laser optimization and inverse design,the necessity for numerous simulations further exacerbates this issue,highlighting the need for fast and accurate simulation methodologies.Here,we introduce an end-to-end model augmented with active learning(E2E-AL)with decent generalization through different dedicated embedding methods over various parameters.On an identical computational platform,the artificial intelligence–driven model is 2000 times faster than the conventional simulation method.Benefiting from the active learning strategy,the E2E-AL model achieves decent precision with only two-thirds of the training samples compared with the case without such a strategy.Furthermore,we demonstrate a multi-objective inverse design of the CPA systems enabled by the E2E-AL model.The E2E-AL framework manifests the potential of becoming a standard approach for the rapid and accurate modeling of ultrafast lasers and is readily extended to simulate other complex systems. 展开更多
关键词 chirped pulse amplification end-to-end modeling active learning inverse design
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Enhancing hydrogel predictive modeling:an augmented neural network approach for swelling dynamics in pH-responsive hydrogels
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作者 M.A.FARAJI M.ASKARI-SEDEH +1 位作者 A.ZOLFAGHARIAN M.BAGHANI 《Applied Mathematics and Mechanics(English Edition)》 2025年第9期1787-1808,共22页
The pH-sensitive hydrogels play a crucial role in applications such as soft robotics,drug delivery,and biomedical sensors,as they require precise control of swelling behaviors and stress distributions.Traditional expe... The pH-sensitive hydrogels play a crucial role in applications such as soft robotics,drug delivery,and biomedical sensors,as they require precise control of swelling behaviors and stress distributions.Traditional experimental methods struggle to capture stress distributions due to technical limitations,while numerical approaches are often computationally intensive.This study presents a hybrid framework combining analytical modeling and machine learning(ML)to overcome these challenges.An analytical model is used to simulate transient swelling behaviors and stress distributions,and is confirmed to be viable through the comparison of the obtained simulation results with the existing experimental swelling data.The predictions from this model are used to train neural networks,including a two-step augmented architecture.The initial neural network predicts hydration values,which are then fed into a second network to predict stress distributions,effectively capturing nonlinear interdependencies.This approach achieves mean absolute errors(MAEs)as low as 0.031,with average errors of 1.9%for the radial stress and 2.55%for the hoop stress.This framework significantly enhances the predictive accuracy and reduces the computational complexity,offering actionable insights for optimizing hydrogel-based systems. 展开更多
关键词 transient swelling pH-responsive hydrogel neural network data-driven model hydration and stress dynamics
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Investigating the Role of Antimalarial Treatment and Mosquito Nets in Malaria Transmission and Control through Mathematical Modeling
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作者 Azhar Iqbal Kashif Butt Tariq Ismaeel +4 位作者 Sara Khan Muhammad Imran Waheed Ahmad Ismail Abdulrashid Muhammad Sajid Riaz 《Computer Modeling in Engineering & Sciences》 2025年第9期3463-3492,共30页
Malaria is a significant global health challenge.This devastating disease continues to affect millions,especially in tropical regions.It is caused by Plasmodium parasites transmitted by female Anopheles mosquitoes.Thi... Malaria is a significant global health challenge.This devastating disease continues to affect millions,especially in tropical regions.It is caused by Plasmodium parasites transmitted by female Anopheles mosquitoes.This study introduces a nonlinear mathematical model for examining the transmission dynamics of malaria,incorporating both human and mosquito populations.We aim to identify the key factors driving the endemic spread of malaria,determine feasible solutions,and provide insights that lead to the development of effective prevention and management strategies.We derive the basic reproductive number employing the next-generation matrix approach and identify the disease-free and endemic equilibrium points.Stability analyses indicate that the disease-free equilibrium is locally and globally stable when the reproductive number is below one,whereas an endemic equilibrium persists when this threshold is exceeded.Sensitivity analysis identifies the most influential mosquito-related parameters,particularly the bite rate and mosquito mortality,in controlling the spread of malaria.Furthermore,we extend our model to include a treatment compartment and three disease-preventive control variables such as antimalaria drug treatments,use of larvicides,and the use of insecticide-treated mosquito nets for optimal control analysis.The results show that optimal use of mosquito nets,use of larvicides for mosquito population control,and treatment can lower the basic reproduction number and control malaria transmission with minimal intervention costs.The analysis of disease control strategies and findings offers valuable information for policymakers in designing cost-effective strategies to combat malaria. 展开更多
关键词 MALARIA mathematical modeling optimal control mosquito nets anti-malaria drugs stability and sensitivity analysis
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Mouse model of anti-RANKL discontinuation reveals reduced bone mass and quality through disruption of bone remodeling
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作者 Koji Ishikawa Soji Tani +8 位作者 Nobuhiro Sakai Yoshifumi Kudo Hideyo Horiuchi Hiromi Kimura-Suda Masamichi Takami Mayumi Tsuji Katsunori Inagaki Yuji Kiuchi Takako Negishi-Koga 《Bone Research》 2025年第4期1001-1014,共14页
The discontinuation of denosumab[antibody targeting receptor activator of nuclear factor kappa B ligand(RANKL)]therapy may increase the risk of multiple vertebral fractures;however,the underlying pathophysiology is la... The discontinuation of denosumab[antibody targeting receptor activator of nuclear factor kappa B ligand(RANKL)]therapy may increase the risk of multiple vertebral fractures;however,the underlying pathophysiology is largely unknown.In patients who underwent discontinuation after multiple injections of denosumab,the levels of tartrate-resistant acid phosphatase 5b increased compared to pretreatment levels,indicating a phenomenon known as“overshoot.”The rate of decrease in bone mineral density during the withdrawal period was higher than the rate of decrease associated with aging,suggesting that the physiological bone metabolism had broken down.Overshoot and significant bone loss were also observed in mice receiving continuous administration of anti-RANKL antibody after treatment was interrupted,resembling the original pathology.In mice long out of overshoot,bone resorption recovered,but osteoblast numbers and bone formation remained markedly reduced.The bone marrow exhibited a significant reduction in stem cell(SC)antigen 1-and platelet-derived growth factor receptor alpha-expressing osteoblast progenitors(PαS cells)and alkaline phosphatase-positive early osteoblasts.Just before the overshoot phase,the osteoclast precursor cell population expands and RANKL-bearing extracellular vesicles(EVs)became abundant in the serum,leading to robust osteoclastogenesis after cessation of anti-RANKL treatment.Thus,accelerated bone resorption due to the accumulation of RANKLbearing EVs and long-term suppression of bone formation uncoupled from bone resorption leads to the severe bone loss characteristic of denosumab discontinuation. 展开更多
关键词 vertebral fractureshoweverthe decrease bone mineral density bone mass tartrate resistant acid phosphatase b mouse model anti RANKL discontinuation bone remodeling bone quality
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Groundwater quality assessment using multivariate analysis,geostatistical modeling, and water quality index(WQI): a case of study in the Boumerzoug-El Khroub valley of Northeast Algeria 被引量:4
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作者 Oualid Bouteraa Azeddine Mebarki +2 位作者 Foued Bouaicha Zeineddine Nouaceur Benoit Laignel 《Acta Geochimica》 EI CAS CSCD 2019年第6期796-814,共19页
In this study,the analytical data set of 26 groundwater samples from the alluvial aquifer of Boumerzoug-E1 khroub valley has been processed simultaneously with Multivariate analysis,geostatistical modeling,WQI,and geo... In this study,the analytical data set of 26 groundwater samples from the alluvial aquifer of Boumerzoug-E1 khroub valley has been processed simultaneously with Multivariate analysis,geostatistical modeling,WQI,and geochemical modeling.Cluster analysis identified three main water types based on the major ion contents,where mineralization increased from group 1 to group 3.These groups were confirmed by FA/PCA,which demonstrated that groundwater quality is influenced by geochemical processes(water-rock interaction)and human practice(irrigation).The exponential semivariogram model WQI.Groundwater chemistry has a strong spatial structure for Mg,Na,Cl,and NO3,and a moderate spatial structure for EC,Ca,K,HCO3,and SO4.Water quality maps generated using ordinary Kriging are consistent with the HCA and PCA results.All water groups are supersaturated with respect to carbonate minerals,and dissolution of kaolinite and Ca-smectite is one of the processes responsible for hydrochemical evolution in the area. 展开更多
关键词 GROUNDWATER Multivariate analysis Geostatistical modeling Geochemical modeling MINERALIZATION Ordinary Kriging
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Modeling rock specimens through 3D printing: Tentative experiments and prospects 被引量:24
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作者 Quan Jiang Xiating Feng +3 位作者 Lvbo Song Yahua Gong Hong Zheng Jie Cui 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2016年第1期101-111,共11页
Current developments in 3D printing (3DP) technology provide the opportunity to produce rock-like specimens and geotechnical models through additive man- ufacturing, that is, from a file viewed with a computer to a ... Current developments in 3D printing (3DP) technology provide the opportunity to produce rock-like specimens and geotechnical models through additive man- ufacturing, that is, from a file viewed with a computer to a real object. This study investigated the serviceability of 3DP products as substitutes for rock specimens and rock-type materials in experimental analysis of deformation and failure in the laboratory. These experiments were performed on two types of materials as follows: (1) compressive experiments on printed sand-powder specimens in different shapes and structures, including intact cylinders, cylinders with small holes, and cuboids with pre-existing cracks, and (2) com- pressive and shearing experiments on printed polylactic acid cylinders and molded shearing blocks. These tentative tests for 3DP technology have exposed its advantages in produc- ing complicated specimens with special external forms and internal structures, the mechanical similarity of its product to rock-type material in terms of deformation and failure, and its precision in mapping shapes from the original body to the trial sample (such as a natural rock joint). These experiments and analyses also successfully demonstrate the potential and prospects of 3DP technology to assist in the deformation and failure analysis of rock-type materials, as well as in the sim- ulation of similar material modeling experiments. 展开更多
关键词 Rock mechanics Similar material 3Dprinting Geotechnical model Deformation and failure
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Investigating the dynamic mechanical behaviors of polyurea through experimentation and modeling 被引量:18
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作者 Hao Wang Ximin Deng +3 位作者 Haijun Wu Aiguo Pi Jinzhu Li Fenglei Huang 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2019年第6期875-884,共10页
Polyurea is widely employed as a protective coating in many fields because of its superior ability to improve the anti-blast and anti-impact capability of structures.In this study,the mechanical properties of polyurea... Polyurea is widely employed as a protective coating in many fields because of its superior ability to improve the anti-blast and anti-impact capability of structures.In this study,the mechanical properties of polyurea XS-350 were investigated via systematic experimentation over a wide range of strain rates(0.001-7000 s^-1)by using an MTS,Instron VHS,and split-Hopkinson bars.The stress-strain behavior of polyurea was obtained for various strain rates,and the effects of strain rate on the primary mechanical properties were analyzed.Additionally,a modified rate-dependent constitutive model is proposed based on the nine-parameter Mooney-Rivlin model.The results show that the stress-strain curves can be divided into three distinct regions:the linear-elastic stage,the highly elastic stage,and an approximate linear region terminating in fracture.The mechanical properties of the polyurea material were found to be highly dependent on the strain rate.Furthermore,a comparison between model predictions and the experimental stress-strain curves demonstrated that the proposed model can characterize the mechanical properties of polyurea over a wide range of strain rates. 展开更多
关键词 POLYUREA Strain rate effect Dynamic mechanical properties Constitutive model
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Centrifuge modeling of buried continuous pipelines subjected to normal faulting 被引量:13
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作者 Majid Moradi Mahdi Rojhani +1 位作者 Abbas Galandarzadeh Shiro Takada 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2013年第1期155-164,共10页
Seismic ground faulting is the greatest hazard for continuous buried pipelines.Over the years,researchers have attempted to understand pipeline behavior mostly via numerical modeling such as the finite element method.... Seismic ground faulting is the greatest hazard for continuous buried pipelines.Over the years,researchers have attempted to understand pipeline behavior mostly via numerical modeling such as the finite element method.The lack of well-documented field case histories of pipeline failure from seismic ground faulting and the cost and complicated facilities needed for full-scale experimental simulation mean that a centrifuge-based method to determine the behavior of pipelines subjected to faulting is best to verify numerical approaches.This paper presents results from three centrifuge tests designed to investigate continuous buried steel pipeline behavior subjected to normal faulting.The experimental setup and procedure are described and the recorded axial and bending strains induced in a pipeline are presented and compared to those obtained via analytical methods.The influence of factors such as faulting offset,burial depth and pipe diameter on the axial and bending strains of pipes and on ground soil failure and pipeline deformation patterns are also investigated.Finally,the tensile rupture of a pipeline due to normal faulting is investigated. 展开更多
关键词 centrifuge models buried pipeline normal faulting EARTHQUAKE permanent ground deformation
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Distributed modeling of direct solar radiation on rugged terrain of the Yellow River Basin 被引量:4
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作者 ZENG Yan QIU Xinfa +1 位作者 LIU Changming JIANG Aijun 《Journal of Geographical Sciences》 SCIE CSCD 2005年第4期439-447,共9页
Due to the influences of local topographical factors and terrain inter-shielding, calculation of direct solar radiation (DSR) quantity of rugged terrain is very complex. Based on digital elevation model (DEM) data... Due to the influences of local topographical factors and terrain inter-shielding, calculation of direct solar radiation (DSR) quantity of rugged terrain is very complex. Based on digital elevation model (DEM) data and meteorological observations, a distributed model for calculating DSR over rugged terrain is developed. This model gives an all-sided consideration on factors influencing th a resolution of 1 km × 1 km for thDSR. Using the developed model, normals of annual DSR quantity wie Yellow River Basin was generated, with DEM data as the general characterization of terrain. Characteristics of DSR quantity influenced by geographic and topographic factors over rugged terrain were analyzed thoroughly. Results suggest that: influenced by local topographic factors, i.e. azimuth, slope and so on, and annual DSR quantity over mountainous area has a clear spatial difference; annual DSR quantity of sunny slope (or southern slope) of mountains is obviously larger than that of shady slope (or northern slope). The calculated DSR quantity of the Yellow River Basin is provided in the same way as other kinds of spatial information and can be employed as basic geographic data for relevant studies as well. 展开更多
关键词 direct solar radiation (DSR) rugged terrain digital elevation model (DEM) distributed model Yellow River Basin
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Structure and kinematic analysis of the deepwater area of the Qiongdongnan Basin through a seismic interpretation and analogue modeling experiments 被引量:11
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作者 SUN Zhen WANG Zhenfeng +3 位作者 SUN Zhipeng WANG Zhangwen ZHANG Wei HE Lijuan 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2015年第4期32-40,共9页
Located at the northwest continental slope of the South China Sea, the Qiongdongnan Basin bears valley-shaped bathymetry deepening toward east. It is separated from the Yinggehai Basin through NW-trending Indo-China-R... Located at the northwest continental slope of the South China Sea, the Qiongdongnan Basin bears valley-shaped bathymetry deepening toward east. It is separated from the Yinggehai Basin through NW-trending Indo-China-Red River shear zone, and connected with NW subsea basin through the Xisha Trough. Along with the rapid progress of the deepwater exploration, large amounts of high resolution geophysical and geological data were accumulated. Scientific researches about deepwater basins kept revealing brand new tectonic and sedimentary discoveries. In order to summarize the structural features and main controlling factors of the deepwater Qiongdongnan Basin, a series of researches on basin architecture, fault activities, tectonic deformation and evolution were carried out. In reference to analogue modeling experiments, a tectonic situation and a basin formation mechanism were discussed. The researches indicate that:the northern boundary of the Qiongdongnan Basin is strongly controlled by No. 2 fault. The overlapping control of two stress fields from the east and the west made the central depression zone extremely thinned. Combined with the changed stress field, the segmentation of a preexisting weakness zone made the sags in the east experiencing different rifting histories from the west ones. The NE-trending west segment of the Qiongdongnan Basin experienced strong rifting during Eocene, while the roughly EW-trending sags in the east segment show strong rifting during late Eocene and early Oligocene. Local structures such as NW-trending basal fault and inherited uplifts controlled the lateral segmentation. So first order factors such as regional stress field and preexisting weakness zone controlled the basin zonation, while the second order factors determined the segmentation from east to west. 展开更多
关键词 rifting structure basin formation mechanism profile interpretation analogue modeling experiments Qiongdongnan Basin
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Uplift mechanism for a shallow-buried structure in liquefi able sand subjected to seismic load: centrifuge model test and DEM modeling 被引量:5
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作者 Zhou Jian Wang Zihan +1 位作者 Chen Xiaoliang Zhang Jiao 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2014年第2期203-214,共12页
Based on a centrifuge model test and distinct element method(DEM), this study provides new insights into the uplift response of a shallow-buried structure and the liquefaction mechanism for saturated sand around the s... Based on a centrifuge model test and distinct element method(DEM), this study provides new insights into the uplift response of a shallow-buried structure and the liquefaction mechanism for saturated sand around the structure under seismic action. In the centrifuge test, a high-speed microscopic camera was installed in the structure model, by which the movements of particles around the structure were monitored. Then, a two-dimensional digital image processing technology was used to analyze the microstructure of saturated sand during the shaking event. Herein, a numerical simulation of the centrifuge experiment was conducted using a two-phase(solid and fl uid) fully coupled distinct element code. This code incorporates a particle-fl uid coupling model by means of a "fi xed coarse-grid" fl uid scheme in PFC3D(Particle Flow Code in Three Dimensions), with the modeling parameters partially calibrated based on earlier studies. The physical and numerical models both indicate the uplifts of the shallow-buried structure and the sharp rise in excess pore pressure. The corresponding micro-scale responses and explanations are provided. Overall, the uplift response of an underground structure and the occurrence of liquefaction in saturated sand are predicted successfully by DEM modeling. However, the dynamic responses during the shaking cannot be modeled accurately due to the restricted computer power. 展开更多
关键词 centrifuge modeling underground structure LIQUEFACTION distinct element method saturated sand
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Centrifuge modeling of PGD response of buried pipe 被引量:8
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作者 Michael O'Rourke Vikram Gadicherla Tarek Abdoun 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2005年第1期69-73,共5页
A new centrifuge based method for determining the response of continuous buried pipe to PGD is presented. The physical characteristics of the RPI's 100 g-ton geotechnical centrifuge and the current lifeline experi... A new centrifuge based method for determining the response of continuous buried pipe to PGD is presented. The physical characteristics of the RPI's 100 g-ton geotechnical centrifuge and the current lifeline experiment split-box are described: The split-box contains the model pipeline and surrounding soil and is manufactured such that half can be offset, in flight, simulating PGD. In addition, governing similitude relations which allow one to determine the physical characteristics, (diameter, wall thickness and material modulus of elasticity) of the model pipeline are presented. Finally, recorded strains induced in two buried pipes with prototype diameters of 0.63 m and 0.95 m (24 and 36 inch) subject to 0.6 and 2.0 meters (2 and 6 feet) of full scale fault offsets and presented and compared to corresponding FE results. 展开更多
关键词 EARTHQUAKES buried pipe permanent ground deformation centrifuge models fault crossings lifeline earthquake engineering
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Dynamic Analysis on Rifting Stage of Pearl River Mouth Basin through Analogue Modeling 被引量:7
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作者 孙珍 周蒂 +4 位作者 孙龙涛 陈长民 庞雄 姜建群 樊浩 《Journal of Earth Science》 SCIE CAS CSCD 2010年第4期439-454,共16页
The Pearl River Mouth basin (PRMB) is a marginal sedimentary basin of the South China Sea. It trends NE and is divided into three segments from west to east by two NW-trending faults. Changing dramatically in struct... The Pearl River Mouth basin (PRMB) is a marginal sedimentary basin of the South China Sea. It trends NE and is divided into three segments from west to east by two NW-trending faults. Changing dramatically in structures along and across strike, the PRMB is a good example to analyze main factors that might control the process of a continental rift basin's extension. Through five series of analogue experiments, we investigate the role of different factors, such as pre-existing discontinuities of crust, rheological profiles of lithosphere, kinematics of extension and presence of magmatic bodies and strong crustal portions (rigid massifs) on the development of basin's structures. After being compared with the architecture of the natural prototype, the results of the analogue models were compared with the architecture of the natural prototype and used to infer the role of the different factors controlling the formation and evolution of the PRMB. The main conclusions are as follows. (1) Affected by pre-Cenozoic structures, the PRMB was controlled by crosscut NE- and NW-trending initial faults, and the NW-trending Yitong'ansha (--~l~) fault may be a through-going fault along dip and offset the NE-trending rift and faults, while the Enpingdong (和统暗沙) fault might exist only in the middle and south. (2) The NW-trending faults may orient WNW to be sinistrally transtensional under SE to nearly NS extension. (3) The thickness ratio of brittle over ductile crust in Baiyun (白云) sag is lessthan normal, suggesting an initially hot and weak lithosphere. (4) The magma must have taken part in the rifting process from early stage, it may occur initially upon or slightly south of the divergent boundary in the middle segment. The flow of magma toward rift boundary faults caused extra vertical subsidence above the initial magma reservoir without creating a large extensional fault. (5) The rigid massif contributed to the strain partition along and across basin strike. 展开更多
关键词 Pearl River Mouth basin analogue modeling controlling factor of continental rift basin.
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Dynamic Analysis of Yinggehai Basinthrough Analogue Modeling 被引量:2
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作者 Sun Zhen Faculty of Earth Resources, China University of Geosciences, Wuhan 430074 Zhou Di South China Sea Institute of Oceanology, Guangzhou 510301 Zeng Zuoxun Faculty of Earth Sciences, China University of Geosciences, Wuhan 430074 Zhong Zhi 《Journal of Earth Science》 SCIE CAS CSCD 2000年第1期81-85,共5页
The Yinggehai basin lies in the northwestern shelf of the South China Sea. The maximum depth of the Cenozoic sediments is 17 km. Present gas exploration was mainly in the Neogene strata. But it is estimated that the P... The Yinggehai basin lies in the northwestern shelf of the South China Sea. The maximum depth of the Cenozoic sediments is 17 km. Present gas exploration was mainly in the Neogene strata. But it is estimated that the Paleocene sediments (~8 km in thickness) has productive potential. So research on the Paleogene rifting structure will greatly enlarge the exploration area. 3D scaled sandbox is the analogue model for the Yinggehai basin. Comparing modeling with the basin by the positions and movement of depocenters, the geometric similarity, we aim to summarize the dynamic situation of Yinggehai basin during the rifting stage and to cast an objective prediction on the structures in the areas without data. 展开更多
关键词 dynamic analysis rifting structure analogue modeling.
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