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Multi-layer perceptron-based data-driven multiscale modelling of granular materials with a novel Frobenius norm-based internal variable

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第6期16卷 2198-2218页

作者： mengqi wang Y.T.Feng Shaoheng Guan Tongming Qu Zienkiewicz Centre for Computational Engineering Faculty of Science and EngineeringSwansea UniversitySwanseaWalesSA18EPUK Institute of Theoretical and Computational Physics Graz University of TechnologyGraz8010Austria Department of Civil and Environmental Engineering Hong Kong University of Science and TechnologyClearwater BayKowloonHong KongChina

One objective of developing machine learning(ML)-based material models is to integrate them with well-established numerical methods to solve boundary value problems(BVPs).In the family of ML models,recurrent neural networks(RNNs)have been extensively applied to capture history-dependent constitutive responses of granular materials,but these multiple-step-based neural networks are neither sufficiently efficient nor aligned with the standard finite element method(FEM).Single-step-based neural networks like the multi-layer perceptron(MLP)are an alternative to bypass the above issues but have to introduce some internal variables to encode complex loading *** this work,one novel Frobenius norm-based internal variable,together with the Fourier layer and residual architectureenhanced MLP model,is crafted to replicate the history-dependent constitutive features of representative volume element(RVE)for granular *** obtained ML models are then seamlessly embedded into the FEM to solve the BVP of a biaxial compression case and a rigid strip footing *** obtained solutions are comparable to results from the FEM-DEM multiscale modelling but achieve significantly improved *** results demonstrate the applicability of the proposed internal variable in enabling MLP to capture highly nonlinear constitutive responses of granular materials.

关键词： Granular materials History-dependence Multi-layer perceptron(MLP) Discrete element method FEM-DEM Machine learning

Carbon dots-based fluorescence sensor for two-photon imaging of pH in diabetic mice

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Frontiers of Chemical Science and Engineering 2023年第3期17卷 298-306页

作者： Li Yang mengqi wang Xiaoyu Gu Wei Zhang Ping Li Wen Zhang Hui wang Bo Tang College of Chemistry Chemical Engineering and Materials ScienceCollaborative Innovation Center of Functionalized Probes for Chemical Imaging in Universities of ShandongKey Laboratory of Molecular and Nano ProbesMinistry of EducationInstitute of Biomedical SciencesShandong Normal UniversityJinan 250014China

Herein,a reversible pH fluorescent sensor was developed using caffeic acid as the precursor by one-step solvothermal synthesis *** carbon dots-based sensor(CA-CDs)exhibited pH-dependent increase in fluorescence intensity and showed linear relationship in the range of pH 6.60 and ***,the fluorescence sensor has a reversible response to pH ***,the CA-CDs has been successfully applied for two-photon imaging of the pH in liver and kidney of diabetic *** results showed that the pH value in kidney of diabetic mice was lower than that of the normal mice,while the pH value in liver of diabetic mice was almost the same as that of the normal *** present study provides a simple analytical method for pH detection suitable for in vivo.

关键词： carbon dots two-photon imaging pH diabetic mice

Deep Learning Predicts Stress–Strain Relations of Granular Materials Based on Triaxial Testing Data

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Computer Modeling in Engineering & Sciences 2021年第7期128卷 129-144页

作者： Tongming Qu Shaocheng Di Y.T.Feng Min wang Tingting Zhao mengqi wang Zienkiewicz Centre for Computational Engineering College of EngineeringSwansea UniversitySwanseaWalesSA18EPUK College of Shipbuilding Engineering Harbin Engineering UniversityHarbin150001China Institute of Applied Mechanics and Biomedical Engineering Taiyuan University of TechnologyTaiyuan030024China Fluid Dynamics and Solid Mechanics Group Theoretical DivisionLos Alamos National LaboratoryLos AlamosNM 87545USA

This study presents an AI-based constitutive modelling framework wherein the prediction model directly learns from triaxial testing data by combining discrete element modelling(DEM)and deep learning.A constitutive learning strategy is proposed based on the generally accepted frame-indifference assumption in constructing material constitutive *** low-dimensional principal stress-strain sequence pairs,measured from discrete element modelling of triaxial testing,are used to train recurrent neural networks,and then the predicted principal stress sequence is augmented to other high-dimensional or general stress tensor via coordinate *** detailed hyperparameter investigations,it is found that long short-term memory(LSTM)and gated recurrent unit(GRU)networks have similar prediction performance in constitutive modelling problems,and both satisfactorily predict the stress responses of granular materials subjected to a given unseen strain ***,the unique merits and ongoing challenges of data-driven constitutive models for granular materials are discussed.

关键词： Deep learning granular materials constitutive modelling discrete element modelling coordinate transformation LSTM GRU

Novel 1,3,5-thiadiazine-2-thione derivatives containing a hydrazide moiety:Design, synthesis and bioactive evaluation against phytopathogenic fungi in vitro and in vivo

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Chinese Chemical Letters 2019年第7期30卷 1419-1422页

作者： Xiaobin wang Xincan Fu Min Chen An wang Jinghua Yan Yudong Mei mengqi wang Chunlong Yang Jiangsu Key Laboratory of Pesticide Science Nanjing Agricultural University Nanjing 210095 China Department of Chemistry College of Sciences Nanjing Agricultural University Nanjing 210095 China

A series of novel 1,3,5-thiadiazine-2-thione derivatives bearing a hydrazide moiety were designed, synthesized and evaluated for their antifungal activities against Rhizoctonia solani (Rs), Fusarium graminearum (Fg), Botrytis cinerea (Bc) and Colletotrichum capsici (Cc). The in vitro antifungal bioassays indicated that most of title compounds displayed good selectivity and specificity aganist Rs relative to Fg, Bc and Cc. Strikingly, the title compound N'-(4-chlorophenyl)-2-(5-phenyl-6-thioxo-1,3,5-thiadiazinan-3-yl)acethydrazide (5b) obviously inhibited the Rs growth in vitro with the EC50 value of 0.24μg/mL, which is approximately 2-folds more effective than the commercialized fungicide carbendazim (0.55 μg/mL). The in vivo anti-Rs effects of title compound 5b were further evaluated on rice leaves with control efficacies of 98.58% at 200 μg/mL and 61.27% at 100 μg/mL. The above researches provide a significant reference for the further structural optimization of 1,3,5-thiadiazine-2-thione derivatives bearing a hydrazide moiety as potential fungicides.

关键词： 1,3,5-Thiadiazine-2-thione Hydrazide Crop protection Antifungal activity Rhizoctonia solani

Autonomous Cooperative Vehicle Coordination at Road Intersections

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Journal of Communications and Information Networks 2019年第1期4卷 78-87页

作者： Yangan Mo mengqi wang Tingting Zhang Qinyu Zhang Harbin Institute of Technology(Shenzhen) Shenzhen 518055China Peng Cheng Laboratory Shenzhen 518055China

Appropriate traffic coordination at road intersections plays a crucial part in modern intelligent transportation *** this paper,we first try to extend the traditional single collision-set coordination strategy to multiple-collision-set strategies,by which the traffic throughput can be significantly *** the existing centralized coordination methods,two low complexity coordination methods are proposed based on the multi-agents Q-learning *** results show that,the proposed high throughput strategies are able to provide safe and efficient traffic ***,since only local information is required,the coordination complexity can be reduced,which is attractive in highly dynamic real time scenarios.

关键词： intersection coordination multiple-colli-sion-set distributed strategies multiple agents reinforcement learning

Characteristics of Vertical Distributions of Fatty Acids in Surface Sediments of the Yellow Sea and East China Sea

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Journal of Ocean University of China 2018年第5期17卷 1123-1134页

作者： LOPES Evanildo O. wang mengqi CHEN Ying YANG Guipeng DING Haibing College of Chemistry and Chemical Engineering Ocean University of ChinaQingdao 266100China Key Laboratory of Marine Chemistry Theory and Technology Ministry of EducationOcean University of ChinaQingdao 26610Q China China State Shipbuilding Corporation Electronics Technology Co.Ltd. Beijing 100015China Qingdao Collaborative Innovation Center of Marine Science and Technology Ocean University of ChinaQingdao 26610Q China Qingdao National Laboratory of Marine Science and Technology Qingdao 266100China

Fatty acids(FAs) in sediment collected from three different stations in the Yellow Sea and the East China Sea were analyzed for their distributions and to determine evidence of harmful algal blooms in the sediment *** diverse FAs were found in the Yellow Sea(YS) station,whereas in the two stations of the East China Sea(ECS) the FAs were more *** of some FA species in the two ECS stations displayed an occasional surge in their vertical *** highest concentration of FAs was found in the surface layer of station QT3(43.28 μg g^(-1)).Monounsaturated FAs were more susceptible to degradation compared to their saturated counterparts,and changes of 16:0,18:2 and 20:5 accounted for the most variability in total concentrations of FAs as those species made up most of the quantified *** origins of the major fraction of FAs were attributed to autotrophic sources,and bacterial FAs accounted for only a small fraction of the total FAs in the *** availability was a possible regulating factor controlling bacteria abundances in marine sediments in the ECS and the YS.A principal component analysis(PCA) was applied to analyze the FA dataset and to reveal the principal environmental factors that control the composition of FAs in the ***2,which explains 15% of the variance,was estimated to reflect the diagenetic effects on the FA compositional changes in sediments influenced by bacterial degradation.

关键词： fatty acids Yellow Sea East China Sea sediments diagenesis

Electrical properties of dry polycrystalline olivine mixed with various chromite contents: Implications for the high conductivity anomalies in subduction zones

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Geoscience Frontiers 2021年第5期12卷 138-148页

作者： Wenqing Sun Jianjun Jiang Lidong Dai Haiying Hu mengqi wang Yuqing Qi Heping Li Key Laboratory of High-Temperature and High-Pressure Study of the Earth's Interior Institute of GeochemistryChinese Academy of SciencesGuiyang 550081China Shandong Provincial Key Laboratory of Water and Soil Conservation and Environmental Protection College of Resources and EnvironmentLinyi UniversityLinyi 276000China University of Chinese Academy of Sciences Beijing 100049China

Chromite,a crucial high-conductivity mineral phase of peridotite in ophiolite suites,has a significant effect on the electrical structure of subduction *** electrical conductivities of sintered polycrystalline olivine containing various volume percents of chromite(0,4,7,10,13,16,18,21,23,100 vol.%)were measured using a complex impedance spectroscopic technique in the frequency range of 10^(−1)-10^(6) Hz under the conditions of 1.0-3.0 GPa and 873-1223 *** relationship between the conductivities of the chromite-bearing olivine aggregates and temperatures conformed to the Arrhenius *** positive effect of pressure on the conductivities of the olivine-chromite systems was much weaker than that of *** chromite content had an important effect on the conductivities of the olivine-chromite systems,and the bulk conductivities increased with increasing volume fraction of chromite to a certain *** inclusion of 16 vol.%chromites dramatically enhanced the bulk conductivity,implying that the percolation threshold of interconnectivity of chromite in the olivine-chromite systems is-16 vol.%.The fitted activation enthalpies for pure polycrystalline olivine,polycrystalline olivine with isolated chromite,polycrystalline olivine with interconnected chromites,and pure polycrystalline chromite were 1.25,0.78-0.87,0.48-0.54,and 0.47 eV,*** on the chemical compositions and activation enthalpies,small polaron conduction was proposed to be the dominant conduction mechanism for polycrystalline olivine with various chromite ***,the conductivities of polycrystalline olivine with interconnected chromite(10-1.5-100.5 S/m)provides a reasonable explanation for the high conductivity anomalies in subduction-related tectonic environments.

关键词： Electrical conductivity Chromite Olivine High pressure Conduction mechanism High conductivity anomaly

Enhanced Microwave Absorption for High Filler Content Composite Molded from Polymer Coated Flaky Carbonyl Irons Modified by Silane Coupling Agents

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Journal of Wuhan University of Technology(Materials Science) 2023年第1期38卷 42-51页

作者：崔正明 MA Guoqing wang mengqi LUO Chuangyu CHEN Zhihong MA Huiru LI Qifan 李维 State Key Laboratory of Advanced Technology for Materials Synthesis and Processing School of Materials Science and EngineeringWuhan University of TechnologyWuhan 430070China School of Science Wuhan University of TechnologyWuhan 430070China Department of Chemistry School of ChemistryChemical Engineering and Life ScienceWuhan University of TechnologyWuhan 430070China School of Physics and Electronic Science Hubei UniversityWuhan 430062China

A microwave absorbing sheet with a high complex permeability and a relatively low complex permittivity is obtained by molding of the densely coated flaky carbonyl iron particles(FCIPs)by styrenebutadiene-styrene block copolymer(SBS)in the assistance of coupling agent *** molding of the core-shell FCIPs without adding extra binder results in a large permeability due to the high filling ratio(55vol%)of ***,the permittivity is well suppressed by the dense insulate polymer shell on the FCIPs,avoiding the severe impedance mismatch problem of the high filler content microwave absorbing *** show that modifying the surface of FCIPs by proper amount of silane coupling agent is critical for the coating quality of the SBS shell,which is verified by resistivity and corrosion current density measurements,and can be interpreted by improved interfacial compatibility between the modified FCIPs and *** obtained microwave absorbing sheet shows a minimum reflection loss of-38.74 dB at 1.57 GHz and has an effective absorption bandwidth from 1.1 to 2.3 GHz at a relatively small thickness of 2 mm.

关键词： microwave absorber coating quality magnetic permeability permittivity low frequency

Carbon dots confined nanosheets assembled NiCO_(2)S_(4)@CDs cross-stacked architecture for enhanced sodium ion storage

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Chinese Chemical Letters 2024年第7期35卷 508-513页

作者： Binyang Qin mengqi wang Shimei Wu Yining Li Chilin Liu Yufei Zhang Haosen Fan School of Chemistry and Chemical Engineering Guangzhou UniversityGuangzhou 510006China

Na^(+)batteries(SIBs)have been emerging as the most promising candidate for the next generation of secondary ***,the development of high-performance and cost-effective anode materials is urgently needed for the large-scale applications of *** this study,carbon dots confined bimetallic sulfide(NiCO_(2)S_(4))architecture(NiCO_(2)S_(4)@CDs)was proposed and synthesized from assembling nanosheets into cross-stacked superstructure and the subsequent confinement of carbon *** novel decussated structure assembly from nanosheets is greatly beneficial to the structure stability of electrode material during the successive charge/discharge ***,the CDs based carbon conductive network can enhance the electrical conductivity for facilitating the easy transport of electron/Na^(+).Benefitting from these advantages,NiCO_(2)S_(4)@CDs exhibits high-rate performance and an ultralong cycling life in ***,the specific capacity of NiCO_(2)S_(4)@CDs can reach the discharge specific capacity as high as 568.9 mAh/g at 0.5 A/g,which can also maintain 302.7 m Ah/g after 750 cycles at 5.0 A/***,ex-situ characterization techniques such as ex-situ XRD and ex-situ XPS were employed to further explore the sodium storage mechanism of the NiCO_(2)S_(4)@CDs anode.

关键词： Carbon dots Sodium ion batteries NiCo_(2)S_(4)@CDs Cross-stacked architecture Ex-situ XRD and XPS