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A digital twins enabled underwater intelligent internet vehicle path planning system via reinforcement learning and edge computing

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Digital Communications and Networks 2024年第2期10卷 282-291页

作者： Jiachen Yang Meng xi Jiabao Wen Yang Li Houbing Herbert song School of Electrical and Information Engineering Tianjin UniversityTianjin300072China Security and Optimization for Networked Globe Laboratory(song Lab) Embry-Riddle Aeronautical UniversityDaytona BeachFL32114USA

The Autonomous Underwater Glider(AUG)is a kind of prevailing underwater intelligent internet vehicle and occupies a dominant position in industrial applications,in which path planning is an essential *** to the complexity and variability of the ocean,accurate environment modeling and flexible path planning algorithms are pivotal *** traditional models mainly utilize mathematical functions,which are not complete and *** existing path planning algorithms depend on the environment and lack *** overcome these challenges,we propose a path planning system for underwater intelligent internet *** applies digital twins and sensor data to map the real ocean environment to a virtual digital space,which provides a comprehensive and reliable environment for path *** design a value-based reinforcement learning path planning algorithm and explore the optimal network structure *** path simulation is controlled by a closed-loop model integrated into the terminal vehicle through edge *** integration of state input enriches the learning of neural networks and helps to improve generalization and *** task-related reward function promotes the rapid convergence of the *** experimental results prove that our reinforcement learning based path planning algorithm has great flexibility and can effectively adapt to a variety of different ocean conditions.

关键词： Digital twins Reinforcement learning Edge computing Underwater intelligent internet vehicle Path planning

Corrosion evaluation and resistance study of alloys in chloride salts for concentrating solar power plants

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Rare Metals 2024年第3期43卷 1222-1233页

作者： Dong-Mei Han Yong Shuai Bachirou Guene Lougou Bo-xi Geng xi-Bo He Tian-Tian Yan Jia-Meng song School of Energy Science and Engineering Harbin Institute of TechnologyHarbin150001China

Thermal energy storage(TES)systems based on molten salt are widely used in concentrating solar power(CSP)*** investigation of the corrosion behavior of alloy materials in molten salt is crucial for the correct selection of alloy materials and the design of TES *** this study,the corrosion behavior of 304,310S,316,and In625 alloys in molten chloride salts(27 mol%NaCl-22 mol%KCl-51 mol%MgCl,)was *** evolution of mass loss of the alloy samples with corrosion time and temperature and the analysis of the experimental results by scanning electron microscopy(SEM),energy dispersive spectrometer(EDS),and X-ray diffraction(XRD)revealed the corrosion mechanism of the alloy samples in molten chloride *** main factors affecting the corrosion of the alloy samples were further *** was found that the loose multi-layer corrosion was formed on the surface of the corroded alloy samples with the increase in corrosion ***,the experimental *** that Mo played a positive role in improving the corrosion resistance of the alloy samples because the presence of Mo could inhibit the outward diffusion of alloying element *** work enriches the molten salt corrosion database and provides a reference for the selection of alloy materials for TES systems with potential application in CSP plants.

关键词： Thermal energy storage Molten chloride salt Alloy materials Corrosion mechanism Corrosion resistance

Effect of Incoming Vortex on Secondary Flows in Turbine Cascades with Planar and Non-Axisymmetric Endwall

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Journal of Thermal Science 2024年第1期33卷 138-157页

作者： CAO Zhiyuan WANG Chuxuan song Zhigao GAO xi ZHAO Wei LIU Bo School of Power and Energy Northwestern Polytechnical UniversityXi'an 710072China National Key Laboratory of Science and Technology on Aerodynamic Design and Research Northwestern Polytechnical UniversityXi'an 710072China Institute of Engineering Thermophysics Chinese Academy of SciencesBeijing 100080China School of Aeronautics and Astronautics University of Chinese Academy of SciencesBeijing 100080China

Non-Axisymmetric Endwall Profiling(NAEP) is commonly utilized in turbines to eliminate secondary ***,most of the NAEP methods consider a single-blade row environment without incorporating the effect of the stage *** paper aims to investigate the influence mechanism of the incoming vortex on the endwall secondary flow structures of NAEP in a highly loaded turbine *** model the incoming vortex in a stage environment,this study considers a half-delta wing as the vortex generator at the upstream of the turbine *** NAEP is then carried out for a highly loaded turbine cascade with an in-house numerical optimization design platform subject to no incoming *** simulation is also carried out under the influence of the incoming vortex for the turbine cascades with both planar and non-axisymmetric *** paper furthers investigated the pitchwise effect of the incoming vortex on the near endwall secondary *** results indicate that the NAEP effectively improves the endwall secondary flow of the turbine cascade,where the total pressure loss coefficient and the secondary kinetic energy(SKE) are reduced by 7.3%,and 45.7%,*** is further seen that with the incoming vortex,the NAEP achieves a considerable control effect on the endwall secondary flow of the turbine *** incoming vortex,the NAEP can still achieve considerable control effect on the endwall secondary flow of the turbine cascade;the averaged reductions of loss coefficient and SKE are 7.8% and 14.2%,*** some pitchwise locations,incoming vortex can suppress the convection of cross-passage flow toward the suction corner greatly and reduce the loss coefficient of the baseline *** incoming vortex at 4/7 pitch impinged right at the blade leading edge,leading to the generation of low-momentum fluid,which increased the size and the strength of the horseshoe *** all the pitchwise locations,NAEP can suppress the seco

关键词： non-axisymmetric endwall secondary flow incoming vortex passage vortex stage environment

Rational cathode configuration with bilayer membranes to engineer current-collector-free high-areal-sulfur lithium-sulfur batteries

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Nano Research 2024年第6期17卷 5224-5232页

作者： Jianmei Han Hua Zhang Peng Wang Ning song Xuguang An Baojuan xi Shenglin xiong College of Chemistry and Chemical Engineering Taishan UniversityTai’an 271021China Key Laboratory of the Colloid and Interface Chemistry Ministry of Educationand School of Chemistry and Chemical EngineeringShandong UniversityJinan 250100China School of Mechanical Engineering Chengdu UniversityChengdu 610106China

The application of light-weight current collectors is preferred because of the increased energy density of the *** it in mind,the cathode is designed with self-made paperlike memberane as current collector coupled with another interlayer to enable the high-energy-density lithium-sulfur *** a facile and green step-by-step methodology,the hybrid membrane is finalized successfully,consisting of reduced graphene oxide sheets covering paper-derived carbon(GPC)bearing Fe@Fe2O3 and Fe1−xS@Fe2O3 core-shell nanoparticles(FeFeO/FeSFeO@GPC).The film works as the current collector and interlayer simultaneously considering the porous and conductive *** demonstrated by the electrochemical testing,the FeFeO/FeSFeO@GPC hybrid cell exhibits attractive cycling stability and superior rate *** cell configuration and structural/composition merits of FeFeO/FeSFeO@GPC film facilitate the faster reaction kinetics,conducive to the improvement of capacity *** view of the effective cathode design,the areal sulfur loading is increased to 10.46 mg·cm^(−2)and a reversible capacity of 6.67 mAh·cm^(−2)can be retained after 60 cycles at 0.1 C.

关键词： light-weight self-made current collector core-shell high-areal-sulfur lithium-sulfur batteries

pH-sensitive KHA/CMC-Fe^(3+)@CS hydrogel loading and the drug release properties of riboflavin

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Particuology 2024年第3期86卷 13-23页

作者： Jie song xi Li Yuhua Niu Lijun Chen Zhiqiang Wei Yidan Li Youqian Wang Shaanxi University of Science&Technology Xi'an710021China

To improve drug utilization,reduce the drug administration frequency,increase the release time,and reduce the drug side effects in the human body,we prepared(KHA/CMC-Fe^(3+))@CS hydrogel spheres using green and natural potassium humate(KHA),carboxymethyl cellulose(CMC),and chitosan(CS)as raw materials and Fe3+as a crosslinking agent,and loaded them with riboflavin for drug sustainedrelease study using the drop ball *** tests with FTIR,SEM,TG,and X-ray diffractometer showed that the coordination among KHA,CMC,and Fe^(3+)formed a three-dimensional network structure,where cs was encapsulated on the surface of the hydrogel spheres via noncovalent bonding,resulting in good thermal *** stability,drug loading,swelling,and in vitro release of the(KHA/CMC-Fe^(3+))@CS hydrogel spheres were *** results showed that the hydrogel spheres were significantly pH-sensitive,with 11.16 g/g higher swelling in an alkaline environment(pH=7.4)than that in an acidic environment(pH=1.2).The swelling and drug release process of the hydrogel spheres were analyzed using mathematical models,concluding that the hydrogel swelling follows Schott second-order swelling kinetics,and the drug release mechanism was Fickian delivery mode.

关键词： Potassium humate Hydrogel spheres pH-sensitive Drugsustained-release Drug release model

A Novel Analysis Approach of Uniform Persistence for an Epidemic Model with Quarantine and Standard Incidence Rate

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Acta Mathematicae Applicatae Sinica 2024年第3期40卷 695-707页

作者： song-bai GUO Yu-ling XUE xi-liang LI Zuo-huan ZHENG School of Science Beijing University of Civil Engineering and ArchitectureBeijing 102616China School of Mathematics and Statistics Hainan Normal UniversityHaikou 571158China Academy of Mathematics and Systems Science Chinese Academy of SciencesBeijing 100190China School of Mathematics and Information Science Shandong Technology and Business UniversityYantai 264005China School of Mathematical Sciences University of Chinese Academy of SciencesBeijing 100049China

Inspired by the transmission characteristics of the coronavirus disease 2019(COVID-19),an epidemic model with quarantine and standard incidence rate is first developed,then a novel analysis approach is proposed for finding the ultimate lower bound of the number of infected individuals,which means that the epidemic is uniformly persistent if the control reproduction number R_(c)>*** approach can be applied to the related biomat hem at ical models,and some existing works can be improved by using *** addition,the infection-free equilibrium V^(0)of the model is locally asymptotically stable(LAS)if R_(c)1.

关键词： uniform persistence epidemic model control reproduction number quarantine standard incidence rate

Rational Design of Ruddlesden-Popper Perovskite Ferrites as Air Electrode for Highly Active and Durable Reversible Protonic Ceramic Cells

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Nano-Micro Letters 2024年第9期16卷 308-324页

作者： Na Yu Idris Temitope Bello xi Chen Tong Liu Zheng Li Yufei song Meng Ni Department of Building and Real Estate Research Institute for Sustainable Urban Development(RISUD)and Research Institute for Smart Energy(RISE)The Hong Kong Polytechnic UniversityHung HomKowloonHong KongPeople’s Republic of China The Hong Kong Polytechnic University Shenzhen Research Institute Shenzhen 518057GuangdongPeople’s Republic of China Department of Mechanical and Aerospace Engineering The Hong Kong University of Science and TechnologyClear Water BayHong KongPeople’s Republic of China

Reversible protonic ceramic cells(RePCCs)hold promise for efficient energy storage,but their practicality is hindered by a lack of high-performance air electrode ***-Popper perovskite Sr_(3)Fe_(2)O_(7−δ)(SF)exhibits superior proton uptake and rapid ionic conduction,boosting ***,excessive proton uptake during RePCC operation degrades SF’s crystal structure,impacting *** study introduces a novel A/B-sites co-substitution strategy for modifying air electrodes,incorporating Sr-deficiency and Nb-substitution to create Sr_(2.8)Fe_(1.8)Nb_(0.2)O_(7−δ)(D-SFN).Nb stabilizes SF’s crystal,curbing excessive phase formation,and Sr-deficiency boosts oxygen vacancy concentration,optimizing oxygen *** D-SFN electrode demonstrates outstanding activity and durability,achieving a peak power density of 596 mW cm^(−2)in fuel cell mode and a current density of−1.19 A cm^(−2)in electrolysis mode at 1.3 V,650℃,with excellent cycling *** approach holds the potential for advancing robust and efficient air electrodes in RePCCs for renewable energy storage.

关键词： Reversible protonic ceramic cells Air electrode Ruddlesden-Popper perovskite Hydration Oxygen reduction reaction

A Novel Graph Structure Learning Based Semi-Supervised Framework for Anomaly Identification in Fluctuating IoT Environment

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Computer Modeling in Engineering & Sciences 2024年第9期140卷 3001-3016页

作者： Weijian song xi Li Peng Chen Juan Chen Jianhua Ren Yunni xia School of Computer and Software Engineering Xihua UniversityChengdu610039China West China Second University Hospital Sichuan UniversityChengdu610065China School of Computer Science Chongqing UniversityChongqing400044China

With the rapid development of Internet of Things(IoT)technology,IoT systems have been widely applied in health-care,transportation,home,and other ***,with the continuous expansion of the scale and increasing complexity of IoT systems,the stability and security issues of IoT systems have become increasingly ***,it is crucial to detect anomalies in the collected IoT time series from various ***,deep learning models have been leveraged for IoT anomaly ***,owing to the challenges associated with data labeling,most IoT anomaly detection methods resort to unsupervised learning ***,the absence of accurate abnormal information in unsupervised learning methods limits their *** address these problems,we propose AS-GCN-MTM,an adaptive structural Graph Convolutional Networks(GCN)-based framework using a mean-teacher mechanism(AS-GCN-MTM)for anomaly *** performs better than unsupervised methods using only a small amount of labeled *** Teachers is an effective semi-supervised learning method that utilizes unlabeled data for training to improve the generalization ability and performance of the ***,the dependencies between data are often unknown in time series *** solve this problem,we designed a graph structure adaptive learning layer based on neural networks,which can automatically learn the graph structure from time series *** not only better captures the relationships between nodes but also enhances the model’s performance by augmenting key *** have demonstrated that our method improves the baseline model with the highest F1 value by 10.4%,36.1%,and 5.6%,respectively,on three real datasets with a 10%data labeling rate.

关键词： IoT multivariate time series anomaly detection graph learning semi-supervised mean teachers

Performance optimization of chalcogenide catalytic materials in lithium-sulfur batteries:Structural and electronic engineering

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Chinese Chemical Letters 2024年第7期35卷 147-166页

作者： Jianmei Han Peng Wang Hua Zhang Ning song Xuguang An Baojuan xi Shenglin xiong College of Chemistry and Chemical Engineering Taishan UniversityTai'an 271021China Key Laboratory of Colloid and Interface Chemistry Ministry of EducationSchool of Chemistry and Chemical EngineeringShandong UniversityJi'nan 250100China School of Mechanical Engineering Chengdu UniversityChengdu 610106China

Lithium-sulfur batteries(LSBs)boasting remarkable energy density have garnered significant attention within academic and industrial ***,the progression of LSBs remains constrained by the languid redox kinetics intrinsic to sulfur and the pronounced shuttle effect induced by lithium polysulfides(Li PSs),which seriously affecting the energy density,cycling life and rate *** conceptualization and implementation of catalytic materials stand acknowledged as a propitious stratagem for orchestrating kinetic modulation,particularly in excavating the conversion of LiPSs and has evolved into a focal point for *** them,chalcogenide catalytic materials(CCMs)have shown satisfactory catalytic effects ascribe to the unique physicochemical properties,and have been extensively developed in recent *** the lack of systematic summary regarding the development of CCMs and corresponding performance optimization strategies,herein,we initiate a comprehensive review regarding the recent progress of CCMs for effective collaborative immobilization and accelerated transformation kinetics of Li *** that,the modulation strategies to improve the catalytic activity of CCMs are summarized,including structural engineering(morphology engineering,surface/interface engineering,crystal engineering)and electronic engineering(doping and vacancy,etc.).Finally,the application prospect of CCMs in LSBs is clarified,and some enlightenment is provided for the reasonable design of CCMs serving practical LSBs.

关键词： Lithium-sulfur batteries Chalcogenide Catalytic materials Lithium polysulfides Structural engineering Electronic engineering