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Frontiers of Materials Science 2024年第1期18卷 29-43页

作者： Wei xiao Wei Yang Shantang liu Hubei Key Lab of Novel Reactor&Green Chemical Technology School of Chemistry and Environmental EngineeringWuhan Institute of TechnologyWuhan 430073China Hubei Key Laboratory of Wudang Local Chinese Medicine Research Department of ChemistrySchool of Pharmaceutical SciencesHubei University of MedicineShiyan 442000China

Metal-organic frameworks(MOFs)have attracted widespread attention due to their regular structures,multiple material centers,and various *** are always considered as one kind of ideal templates for developing highly sensitive and selective gas *** this study,the advantages of MOFs with the high specific surface area(71.9891 m^(2)·g^(-1))and uniform morphology were fully utilized,and urchin-like SnO_(2) nanowires were obtained by the hydrothermal method followed by the calcination using Sn-MOFs consisting of the ligand of C_(9)H_(6)O_(6)(H_(3)BTC)and Sn/Ce center ions as sacrificial *** unique urchin-like nanowire structure facilitated gas diffusion and adsorption,resulting in superior gas sensitivity.A series of Ce-doped SnO_(2) nanowires with different doping ratios were synthesized,and their gas sensing properties towards formaldehyde were *** resulted Ce-SnO_(2) was revealed to have high sensitivity(201.2 at 250℃),rapid response(4 s),long-term stability,and good repeatability for formaldehyde sensing,and the gas sensing mechanism of Ce-SnO_(2) exposed to formaldehyde was also systematically discussed.

关键词： Ce-SnO_(2) SnO_(2) gas sensor formaldehyde Sn-MOF

An efficient parallel algorithm of variational nodal method for heterogeneous neutron transport problems

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Nuclear Science and Techniques 2024年第4期35卷 29-45页

作者： Han Yin xiao-Jing liu Teng-Fei Zhang School of Nuclear Science and Engineering Shanghai Jiao Tong UniversityShanghai 2002040China

The heterogeneous variational nodal method(HVNM)has emerged as a potential approach for solving high-fidelity neutron transport ***,achieving accurate results with HVNM in large-scale problems using high-fidelity models has been challenging due to the prohibitive computational *** paper presents an efficient parallel algorithm tailored for HVNM based on the Message Passing Interface *** algorithm evenly distributes the response matrix sets among processors during the matrix formation process,thus enabling independent construction without *** the formation tasks are completed,a collective operation merges and shares the matrix sets among the *** the solution process,the problem domain is decomposed into subdomains assigned to specific processors,and the red-black Gauss-Seidel iteration is employed within each subdomain to solve the response matrix ***-to-point communication is conducted between adjacent subdomains to exchange data along the *** accuracy and efficiency of the parallel algorithm are verified using the KAIST and JRR-3 test *** results obtained with multiple processors agree well with those obtained from Monte Carlo *** parallelization of HVNM results in eigenvalue errors of 31 pcm/-90 pcm and fission rate RMS errors of 1.22%/0.66%,respectively,for the 3D KAIST problem and the 3D JRR-3 *** addition,the parallel algorithm significantly reduces computation time,with an efficiency of 68.51% using 36 processors in the KAIST problem and 77.14% using 144 processors in the JRR-3 problem.

关键词： Neutron transport Variational nodal method Parallelization KAIST JRR-3

Collision-free parking recommendation based on multi-agent reinforcement learning in vehicular crowdsensing

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Digital Communications and Networks 2024年第3期10卷 609-619页

作者： Xin Li Xinghua Lei Xiuwen liu Hang xiao College of Computer Science and Technology China University of Petroleum(East China)QingDao266580China

The recent proliferation of Fifth-Generation(5G)networks and Sixth-Generation(6G)networks has given rise to Vehicular Crowd Sensing(VCS)systems which solve parking collisions by effectively incentivizing vehicle ***,instead of being an isolated module,the incentive mechanism usually interacts with other *** on this,we capture this synergy and propose a Collision-free Parking Recommendation(CPR),a novel VCS system framework that integrates an incentive mechanism,a non-cooperative VCS game,and a multi-agent reinforcement learning algorithm,to derive an optimal parking strategy in real ***,we utilize an LSTM method to predict parking areas roughly for recommendations *** incentive mechanism is designed to motivate vehicle participation by considering dynamically priced parking tasks and social network *** order to cope with stochastic parking collisions,its non-cooperative VCS game further analyzes the uncertain interactions between vehicles in parking *** its multi-agent reinforcement learning algorithm models the VCS campaign as a multi-agent Markov decision process that not only derives the optimal collision-free parking strategy for each vehicle independently,but also proves that the optimal parking strategy for each vehicle is ***,numerical results demonstrate that CPR can accomplish parking tasks at a 99.7%accuracy compared with other baselines,efficiently recommending parking spaces.

关键词： Incentive mechanism Non-cooperative VCS game Multi-agent reinforcement learning Collision-free parking strategy Vehicular crowdsensing

Solvent transport dynamics and its effect on evolution of mechanical properties of nitrocellulose(NC)-based propellants under hot-air drying process

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Defence Technology（防务技术） 2024年第2期32卷 262-270页

作者： Enfa Fu Mingjun Yi Qianling liu Zhenggang xiao Key Laboratory of Special Energy Materials Ministry of EducationSchool of Chemistry and Chemical EngineeringNanjing University of Science and TechnologyNanjing 210094People's Republic of China

Appropriate drying process with optimized controlling of drying parameters plays a vital role in the improvement of the quality and performance of propellant ***,few research on solvent transport dynamics within NC-based propellants was reported,and its effect on the evolution of mechanical properties was not interpreted *** study is conducted to gain a comprehensive understanding of hot-air drying for NC-based propellants and clarify the effect of temperature on solvent transport behavior and further the change of mechanical properties during *** drying kinetic curves show the drying time required is decreased but the steady solvent content is increased and the drying rate is obviously increased with the increase of hot-air temperatures,indicating hot-air temperatures have a significant effect on drying kinetics.A modified drying model was established,and results show it is more appropriate to describe solvent transport behavior within NC-based ***,two linear equations were established to exhibit the relationship between solvent content and its effect on the change of tensile properties,and the decrease of residual solvent content causes an obvious increase of tensile strength and tensile modulus of propellant products,indicating its mechanical properties can be partly improved by adjustment of residual solvent *** outcomes can be used to clarify solvent transport mechanisms and optimize drying process parameters of double-based gun propellants.

关键词： Nitrocellulose-based propellants Solvent transport dynamics Mechanical properties Drying kinetics Effective solvent diffusion coefficient

Strong and tough chitin hydrogel constructed by dehydration and rehydration strategy

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Nano Research 2024年第9期17卷 8192-8199页

作者： Rui-Rui liu Li-bo Mao Shu-Hong Yu Division of Nanomaterials and Chemistry Hefei National Research Center for Physical Sciences at the MicroscaleDepartment of ChemistryInstitute of Biomimetic Materials and ChemistryAnhui Engineering Laboratory of Biomimetic MaterialsUniversity of Science and Technology of ChinaHefei 230026China Institute of Innovative Materials Department of Materials Science and EngineeringDepartment of ChemistrySouthern University of Science and TechnologyShenzhen 518055China

As a renewable,biocompatible,biodegradable soft material,chitin hydrogels have better advantages in stability,antibacterial activity,antifouling,cost,immunogenicity,and so on than most polymer ***,compared with other widely used polymer hydrogels with high strength and toughness,the practical applications of chitin-based hydrogels have been limited by their weak mechanical properties,such as cartilage repair and meniscus ***,we present the design and fabrication of chitin hydrogels with excellent mechanical strength and toughness by a dehydration and rehydration *** sequential dehydration and rehydration processes,the crystalline domains in the chitin hydrogels can be properly *** optimized crystallinity,the elastic modulus of the chitin hydrogels exceeds all previously reported values,and the fracture toughness is even comparable to some synthetic polymer hydrogels,while maintaining a high-water-content of about 80 wt.%.At the same water content,the mechanical properties of the chitin hydrogels are positively correlated with the hydrogel crystallinity,which proves that the change of mechanical properties of hydrogels is not simply dependent on weight *** hydrogels can be further strengthened by incorporating other biopolymers that are intrinsically weak,which makes the hydrogels promising for applications in fields such as cartilage repair and meniscus ***,the hydrogels enable loading and release of water-soluble and poorly water-soluble *** highly extendable strengthening and toughening strategy of chitin and chitin-based biopolymer hydrogels paves the way for their widely applications.

关键词： chitin hydrogel crystallinity rehydration chemical transformation strong and tough

Structure engineering of cathode host materials for Li-S batteries

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Rare Metals 2024年第4期43卷 1370-1389页

作者： Jia-Jun Long Hua Yu Wen-bo liu School of New Energy and Materials Southwest Petroleum UniversityChengdu610500China School of Mechanical Engineering Sichuan UniversityChengdu610065China

Although lithium-sulfur batteries are one of the favorable candidates for next-generation energy storage devices,a few key challenges that have not been addressed have limited its *** challenges include lithium dendrite growth in the anode side,volume change of the active material,poor electrical conductivity,dissolution and migration of poly sulfides,and slow rate of solid-state reactions in the cathode *** the electrochemical performance of lithium-sulfur batteries is greatly affected by the design of the cathode host material,it has also been widely discussed in addressing the abovementioned *** this paper,three design ideas of cathode host materials in terms of microstructure,crystal structure and electronic structure are introduced and ***,the current progress of these three structural design strategies and their effects on the electrochemical performance of lithium-sulfur batteries are discussed in ***,future directions in the structural design of cathode materials for lithium-sulfur batteries are discussed and further perspectives are provided.

关键词： Lithium-sulfur batteries Structure engineering Cathode Host materials

A NEW GLOBAL OPTIMIZATION ALGORITHM FOR MIXED-INTEGER QUADRATICALLY CONSTRAINED QUADRATIC FRACTIONAL PROGRAMMING PROBLEM

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Journal of Computational Mathematics 2024年第3期42卷 784-813页

作者： bo Zhang Yuelin Gao Xia liu xiaoli Huang School of Civil and Hydraulic Engineering School of Mathematics and StatisticsNingxia UniversityYinchuan 750021China School of Mathematics and Information Science North Minzu UniversityYinchuan 750021China Ningxia Province Key Laboratory of Intelligent Information and Data Processing Yinchuan 750021China School of Mathematics and Statistics Ningxia UniversityYinchuan 750021China

The mixed-integer quadratically constrained quadratic fractional programming(MIQCQFP)problem often appears in various fields such as engineering practice,management science and network ***,most of the solutions to such problems are often designed for their unique *** paper puts forward a new global optimization algorithm for solving the problem *** first convert the MIQCQFP into an equivalent generalized bilinear fractional programming(EIGBFP)problem with integer ***,we linearly underestimate and linearly overestimate the quadratic functions in the numerator and the denominator respectively,and then give a linear fractional relaxation technique for EIGBFP on the basis of non-negative *** that,combining rectangular adjustment-segmentation technique and midpointsampling strategy with the branch-and-bound procedure,an efficient algorithm for solving MIQCQFP globally is ***,a series of test problems are given to illustrate the effectiveness,feasibility and other performance of this algorithm.

关键词： Global optimization Branch and bound Quadratic fractional programming Mixed integer programming

Improved catalytic performance of CO_(2) electrochemical reduction reaction towards ethanol on chlorine-modified Cu-based electrocatalyst

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Nano Research 2024年第5期17卷 3761-3768页

作者： Yifan liu Hehua Tang Yitian Zhou bo-Lin Lin School of Physical Science and Technology ShanghaiTech UniversityShanghai 201210China

Effective electrochemical conversion of CO_(2) to value-added liquid multi-carbon products driven by renewable energy is a promising approach to alleviate excessive CO_(2) emission and achieve large-scale renewable energy ***,the selectivity and catalytic activity towards liquid multi-carbon products of CO_(2) electroreduction reaction are still unsatisfactory due to the sluggish C-C coupling process and the formation of complex oxygen-containing ***,designing and fabricating highly effective electrocatalysts is crucial for practical applications in this ***,we developed Cl-modified Cu catalyst(Cu-Cl)for efficient electrochemical reduction of CO_(2) to *** optimal Faradaic efficiency and partial current density of ethanol on the Cu-Cl sample reached 26.2%and 343.2 mA·cm^(-2) at-0.74 V(*** hydrogen electrode(RHE)),which were 1.66 and 1.76 times higher than those of the catalyst without Cl decoration,outperforming those in most previously reported *** functional theory(DFT)calculations revealed that the Cl-modified Cu surface suppressed the parasitic hydrogen evolution reaction(HER)and reduced the energy barrier for the C-C coupling process,making the formation of key intermediates favorable for ethanol ***,the decoration of Cl on the Cu surface facilitated ethanol formation.

关键词： CO_(2)electrochemical reduction halogen chlorine Cu-based catalysts ethanol multi-carbon products

Dynamics of the spatiotemporal velocity of glaciers on the eastern slope of Mount Gongga,China,under climate change

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Advances in Climate Change Research 2024年第3期15卷 490-499页

作者： Yin FU bo ZHANG Qiao liu Guo-Xiang liu Rui ZHANG Institute of Mountain Hazards and Environment Chinese Academy of SciencesChengdu 610299China Faculty of Geosciences and Environmental Engineering Southwest Jiaotong UniversityChengdu 611756China

The quantitative assessment of glacier flow velocity dynamics plays a pivotal role in understanding its response mechanisms concerning climate *** work provides a systematic quantitative assessment of the deceleration status of glaciers in this region by investigating the motion evolution of typical glaciers in Mount Gongga in recent years,thereby revealing the seasonal dynamics and inter-annual evolution over an extensive time *** used the optical flow-small baseline subset(OF-SBAS)method to compute the time-series velocities of the Hai-luogou Glacier and the Mozigou Glacier using 178 archived Sentinel-1 satellite synthetic aperture radar(SAR)images from 2014 to *** findings revealed a prominent seasonal pattern in glacier motion,characterised by cyclic variations in velocity from cold to warm ***,we identified variations in velocities across distinct regions of the glacier surface,underscored by the lag in the peak time node of glacier flow with increasing *** pattern may have been determined by a combination of internal and external factors,including mass accumulation and ablation-driven subglacial drainage,as well as the glacier geomorphological ***,during 2015-2021,the glaciers on the eastern slope of Mount Gongga exhibited an overarching trend of ***,the ablation area of the Hailuogou Glacier recorded the most substantial deceleration,exceeding 8%per *** study underscores the efficacy of the OF-SBAS method in extracting long-term glacier *** work also establishes a robust foundation for the analysis of spatiotemporal fluctuations in glacier movement within the context of climate warming.

关键词： Monsoonal temperate glaciers Synthetic aperture radar(SAR) Glacier movement Hailuogou glacier Mozigou glacier Optical flow-small baseline subset(OF-SBAS)

Root cause of corrosion failure of tin coating on wire clamp in marine atmosphere

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Journal of Iron and Steel Research International 2024年第4期31卷 998-1014页

作者： Zhen Zhong Wang-yan Ly Teng-yuan liu Yi Xie Yang Yang Zhen-zhu Wang Deng-ke Li xiao-bo Li Tang-qing Wu School of Materials Science and Engineering Xiangtan UniversityXiangtan 411105HunanChina Electric Power Research Institute of Guangdong Power Grid Co. Ltd.Guangzhou 510080GuangdongChina Shenyang National L aboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016LiaoningChina School of Materials Science and Engineering.University of Science and Technology of China Shenyang 110016LiaoningChina Electric Power Research Institute State Grid Hunan Electric Power CompanyChangsha 410007HunanChina School of Mechanical Engineering and Mechanics Xiangtan UniversityXiangtan 411105HunanChina School of Information Science and Engineering Changsha Normal UniversityChangsha 410199HunanChina

The failure cause of a tinned copper wire clamp in marine atmosphere was studied systematically by X-ray photoelectron spectroscopy,scanning electron microscopy with energy dispersive spectroscopy and electrochemical *** main components of the green rust on the surface of the damaged wire clamp are SnO_(2),CuO,Cu_(2)Cl(OH)_(3) and CuCO(OH)_(2).Much of green rust distributes at the platform edge along the axial direction on the crimp connection,and severe corrosion and corrosion pits occur at the platform edge zone along the axial *** enriching Cl-at the marine atmosphere and the existing O_(2) in air collectively enhance the corrosion process of the tin coating and the copper *** element model results show that the residual stress and strain of the tin coating are the largest at the platform edge along the axial direction on the crimp connection,and the corresponding electrode potential of the tin coating at this zone drops *** above results indicate that the residual strain increases the driving force of the corrosion electrochemical reactions and accelerates the corrosion rate and the pit corrosion of the tin coating at this zone.

关键词： Tin coating Marine atmosphere Residual strain-Chloride ion Corrosion failure