检索结果-南通市图书馆

Order-Preserved Preset-Time Cooperative Control:A Monotone System-Based Approach

在线全文

学校读者我要写书评

暂无评论

IEEE/CAA Journal of Automatica Sinica 2022年第9期9卷 1603-1611页

作者： Boda ning Qing-Long han the Center for Smart Infrastructure and Digital Construction Swinburne University of TechnologyMelbourneVIC 3122Australia the School of Science Computing and Engineering TechnologiesSwinburne University of TechnologyMelbourneVIC 3122Australia

This paper is concerned with order-preserved preset-time cooperative control of multi-agent systems with directed graphs.A novel monotone system-based approach is proposed to preserve the initial order of agents while guaranteeing the preset-time state agreement.Specifically,three different distributed controllers together with sufficient conditions are designed to realize leaderless consensus,leader-following consensus,and containment control,respectively.The proposed controllers facilitate preset-time deployment of agents in practical scenarios with collision avoidance requirement.Comparison studies through a numerical example are carried out to illustrate the effectiveness of the proposed controllers.

关键词： Collision-avoidance consensus multi-agent systems preset-time control

Adjusting the interfacial adhesion via surface modification to prepare high-performance fibers

在线全文

学校读者我要写书评

暂无评论

Nano Materials Science 2023年第1期5卷 1-14页

作者： ning han Xiaolin Zhao Vijay Kumar Thakur Department of Materials Engineering KU LeuvenLeuven3001Belgium Shenzhen Automotive Research Institute Beijing Institute of TechnologyShenzhen518118GuangdongChina National Engineering Laboratory for Electric Vehicles Beijing Institute of TechnologyBeijing100081BeijingChina Biorefining and Advanced Materials Research Centre Scotland's Rural CollegeScotlandEdinburghEH93JGUK

Ultra-high molecular weight polyethylene(UHMWPE)fiber is a new kind of high-performance fiber.Due to its excellent physical and chemical characteristics,it is widely used in various fields.However,the surface UHMWPE fiber is smooth and demonstrates no-polar groups.The weak interfacial adhesion between fiber and resin seri-ously restricts the applications of UHMWPE fiber.Therefore,the surface modification treatments of UHMWPE fiber are used to improve the interfacial adhesion strength.The modified method by adding nanomaterials elu-cidates the easy fabrication,advanced equipment and proper technology.Thus,the progress of UHMWPE nanocomposite fibers prepared via adding various nanofillers are reviewed.Meanwhile,the effects of other various methods on surface modification are also reviewed.This work advances the various design strategies about nano technologies on improving interfacial adhesion performance via treatment methodologies.

关键词： UHMWPE fiber Surface modification Interfacial adhesion strength Nanocomposites

Estimation of solid concentration in solid-liquid two-phase flow in horizontal pipeline using inverse-problem approach

在线全文

学校读者我要写书评

暂无评论

Particuology 2022年第3期20卷 1-13页

作者： Ji Zhang han Yuan ning Mei Zhe Yan Marine Engineering College of EngineeringOcean University of ChinaQingdao 266100China Offshore Engineering Department of CivilEnvironmental and MiningUniversity of Western Australia35 Stirling HwyCrawleyWA 6009Australia Power Engineering and Engineering Thermophysics School of Mechanical EngineeringShanghai Jiao Tong UniversityShanghai 200240China

In this study,an inverse-problem method was applied to estimate the solid concentration in a solid-liquid two-phase flow.An algebraic slip mixture model was introduced to solve the forward problem of solid-liquid convective heat transfer.The time-average conservation equations of mass,momentum,energy,as well as the volume fraction equation were computed in a computational fluid dynamics(CFD)simulation.The solid concentration in the CFD model was controlled using an external program that included the inversion iteration,and an optimal estimation was performed via experimental measurements.Experiments using a fly-ash-water mixture and sand-water mixture with different solid concentrations in a horizontal pipeline were conducted to verify the accuracy of the inverse-problem method.The estimated results were rectified using a method based on the relationship between the estimated results and estimation error;consequently,the accuracy of the corrected inversion results improved significantly.After a verification through experiments,the inverse-problem method was concluded to be feasible for predicting the solid concentration,as the estimation error of the corrected results was within 7%for all experimental samples for a solid concentration of less than 50%.The inverse-problem method is expected to provide accurate predictions of the solid concentration in solid-liquid two-phase flow systems.

关键词： Solid-liquid two-phase flow Solid concentration estimation Coupling calculation Inverse heat transfer problem Algebraic slip mixture model

AlN precipitation during steel solidification using CA model

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research(International) 2022年第11期29卷 1789-1799页

作者： Lei Cui Yi-han Shi Xiang-ning Meng Key Laboratory for Ecological Metallurgy of Multi-Metallic Ores Northeastern UniversityShenyang 110819LiaoningChina School of Metallurgy Northeastern UniversityShenyang 110819LiaoningChina

Based on the principles of metal solidification and cellular automaton(CA),as well as AlN precipitation thermodynamics and kinetics,a CA model of interdendritic AlN precipitation was established by coupling a large-size mesh describing the dendrite growth of Fe-C-Al-N alloys and a small-size mesh representing AlN precipitation based on transient chemical equilibrium.The results of single dendrite growth stimulated by this model were compared with the Lipton-Glicksman-Kurz solution to verify the correctness of the matrix dendrite growth simulation.The AlN morphology and dimensions obtained from the CA model simulations are following the experimental results.The presence of equiaxed dendrite in the computational domain results in a significant coarsening of the columnar dendrite and a uniform solute distribution around them,and the AlN solid phase fraction decreases.Simulations of AlN precipitation at different wetting angles were also performed,and it was found that the solid phase fraction of AlN decreased with the increase in wetting angle.Thus,it is confirmed that the established model is an effective method to simulate interdendritic AlN precipitation.

关键词： Metal solidification Cellular automaton Wetting angle AlN precipitation Dendrite growth

A comprehensive review for wind,solar,and electrical load forecasting methods

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Global Energy Interconnection 2022年第1期5卷 9-30页

作者： han Wang ning Zhang Ershun Du Jie Yan Shuang han Yongqian Liu Department of Electrical Engineering Tsinghua UniversityBeijing 100084P.R.China Low Carbon Energy Laboratory Tsinghua UniversityBeijing 100084P.R.China State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources North China Electric Power UniversityBeijing 102206P.R.China School of New Energy North China Electric Power UniversityBeijing 102206P.R.China

Wind power,solar power,and electrical load forecasting are essential works to ensure the safe and stable operation of the electric power system.With the increasing permeability of new energy and the rising demand response load,the uncertainty on the production and load sides are both increased,bringing new challenges to the forecasting work and putting forward higher requirements to the forecasting accuracy.Most review/survey papers focus on one specific forecasting object(wind,solar,or load),a few involve the above two or three objects,but the forecasting objects are surveyed separately.Some papers predict at least two kinds of objects simultaneously to cope with the increasing uncertainty at both production and load sides.However,there is no corresponding review at present.Hence,our study provides a comprehensive review of wind,solar,and electrical load forecasting methods.Furthermore,the survey of Numerical Weather Prediction wind speed/irradiance correction methods is also included in this manuscript.Challenges and future research directions are discussed at last.

关键词： Wind power Solar power Electrical load Forecasting Numerical Weather Prediction Correlation

LNP-CpG ODN-adjuvanted varicella-zoster virus glycoprotein E induced comparable levels of immunity with Shingrix^(TM) in VZV-primed mice

在线全文

学校读者我要写书评

暂无评论

Virologica Sinica 2022年第5期37卷 731-739页

作者： ning Luan han Cao Yunfei Wang Kangyang Lin Cunbao Liu Institute of Medical Biology Chinese Academy of Medical Sciences and Peking Union Medical CollegeKunming 650118China

Latent varicella-zoster virus(VZV)may be reactivated to cause herpes zoster,which affects one in three people during their lifetime.The currently available subunit vaccine Shingrix^(TM) is superior to the attenuated vaccine Zostavax®in terms of both safety and efficacy,but the supply of its key adjuvant component QS21 is limited.With ionizable lipid nanoparticles(LNPs)that were recently approved by the FDA for COVID-19 mRNA vaccines as carriers,and oligodeoxynucleotides containing CpG motifs(CpG ODNs)approved by the FDA for a subunit hepatitis B vaccine as immunostimulators,we developed a LNP vaccine encapsulating VZV-glycoprotein E(gE)and CpG ODN,and compared its immunogenicity with Shingrix^(TM) in C57BL/6J mice.The results showed that the LNP vaccine induced comparable levels of gE-specific IgG antibodies to Shingrix^(TM) as determined by enzymelinked immunosorbent assay(ELISA).Most importantly,the LNP vaccine induced comparable levels of cellmediated immunity(CMI)that plays decisive roles in the efficacy of zoster vaccines to Shingrix^(TM) in a VZVprimed mouse model that was adopted for preclinical studies of Shingrix^(TM) .Number of IL-2 and IFN-γsecreting splenocytes and proportion of T helper 1(Th1)cytokine-expressing CD4^(+)T cells in LNP-CpG-adjuvanted VZV-gE vaccinated mice were similar to that of Shingrix^(TM) boosted mice.All of the components in this LNP vaccine can be artificially and economically synthesized in large quantities,indicating the potential of LNP-CpGadjuvanted VZV-gE as a more cost-effective zoster vaccine.

关键词： Varicella zoster virus(VZV) Subunit vaccine Adjuvant Lipid nanoparticle(LNP) CpG oligodeoxynucleotide(CpG ODN) AS01B Humoral immunity Cell-mediated immunity(CMI)

Imaging field-tuned quantum Hall broken-symmetry orders and the quantum Hall conducting channel in a charge-neutral graphene/WSe_(2) heterostructure

在线全文

学校读者我要写书评

暂无评论

中国科学:物理学、力学、天文学英文版 2023年第7期66卷 88-93页

作者： Qi Zheng Mo-han Zhang Ya-ning Ren Ruo-han Zhang Lin He Center for Advanced Quantum Studies Department of PhysicsBeijing Normal UniversityBeijing 100875China

The zeroth Landau level(0LL)in graphene has emerged as a flat band platform in which distinct many-body phases can be explored with unprecedented control by simply tuning the strength and/or direction of the magnetic field.A rich set of quantum Hall ferromagnetic phases with different lattice-scale symmetry-breaking orders are predicted to be realized in high magnetic fields when the 0LL in graphene is half-filled.Here we report on a field-tuned continuous phase transition of different valley orderings in a quantum Hall ferromagnetic phase of charge-neutral graphene on insulating tungsten diselenide(WSe_(2)).The phase transition is clearly revealed by an anomalous field-dependent energy gap in the half-filled 0LL.Using atomic resolution imaging of electronic wavefunctions during the phase transition,we unexpectedly observe the microscopic signatures of fieldtuned continuous-varied valley polarization and valley inversion,which are beyond current theoretical predictions.Moreover,the quantum Hall conducting channel of the graphene is directly imaged when the substrate(WSe_(2))introduces band bending of the 0LL.

关键词： graphene WSe_(2) quantum Hall ferromagnetic valley polarization valley inversion

In-situ study of initiation and extension of nano-thick defect-free channels in irradiated nickel

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2020年第23期58卷 114-119页

作者： Shihao Li ning Gao Weizhong han Center for Advancing Materials Performance from the Nanoscale State Key Laboratory for Mechanical Behavior of MaterialsXi’an Jiaotong UniversityXi’an710049PR China School of Materials Science and Engineering Zhengzhou UniversityZhengzhou450001PR China Institute of Frontier and Interdisciplinary Science and Key Laboratory of Particle Physics and Particle Irradiation Shandong UniversityQingdao266237PR China Institute of Modern Physics Chinese Academy of SciencesLanzhou730000PR China

Radiation defects-induced plastic flow localization is the origin of loss of ductility in irradiated metals.Defect-free channels(DFCs)are a typical form of strain localization that lead to crack initiation and premature failure.A comprehensive understanding of the DFC dynamics is key to managing radiation boosted property degradation.Despite great research efforts,a clear mechanism of DFC remains unknown.Here,our in-situ tests on irradiated Ni pillars provide a real-time observation of the dynamics of DFCs,including DFC initiation,extension and thickening.The merging and spreading of dislocation loops serve as an alternative mechanism of dislocation sources that emit massive dislocations and initiate nano-thick DFCs inside the grain.Nano-thick DFCs were formed through chopping up or sweeping away of loops by mobile dislocations.Annihilation of opposite loops and interactions between loops and vacancies accelerate DFC extension.Activation of multiple dislocation sources and dislocation cross-slips are the mechanisms for DFC thickening.

关键词： Defect-free channel Dislocation loop In-situ Strain localization

Three-Dimensional Direct Numerical Simulation of Flow past A Near-Wall Circular Cylinder:Combined Effects of Gap Ratio and Boundary Layer Thickness on Flow Profiles and Pressure Distribution

在线全文

学校读者我要写书评

暂无评论

China Ocean Engineering 2023年第6期37卷 948-961页

作者： YING Chao HUA Yang WEI Yu-han JI Chun-ning Zhejiang Institute of Hydraulics&Estuary(Zhejiang Institute of Marine Planning and Design) Hangzhou 310020China Shanghai Investigation Design&Research Institute Co.Ltd.Shanghai 200335China State Key Laboratory of Hydraulic Engineering Simulation and Safety Tianjin UniversityTianjin 300072China

Three-dimensional direct numerical simulations of the wake flow downstream of a near-wall circular cylinder at different gap ratios and boundary layer thicknesses are carried out by using the iterative immersed boundary method.The non-dimensional gap between the cylinder and the wall,G/D=0.2,0.6 and 1.0,the non-dimensional boundary layer thickness,δ/D=0.0,0.7 and 1.6,the Reynolds number,Re=350,and the aspect ratio of the cylinder,L/D=25are adopted.High-resolution visualizations of the complex vortex structures at differentδ/D and G/D are presented.The transition of the streamwise vortex mode,the combined effects ofδ/D and G/D on the flow statistics,the pressure and shear stress distribution and the hydrodynamic forces are analyzed.Results show that with decreasing G/D and increasingδ/D,the gap flow and its vortex-shedding are significantly weakened,together with an elongated wake and an enlarged low-velocity area near the wall,leading to the wake mode transition from the two-sided to one-sided vortex-shedding.Different relative positions of the cylinder regarding the boundary layer alter the flow features of the shear layers.With an increase inδ/D,the front stagnation point shifts to the upper surface,and the distance between the flow divergence point and the maximum pressure position increases.The mean drag coefficient and r.***.s.values of drag and lift coefficients decrease with a decrease in G/D and an increase inδ/D,while the mean lift coefficient increases with decreasing G/D but decreases with increasingδ/D.

关键词： cylinder wake near-wall effect direct numerical simulation boundary layer thickness gap ratio