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A Sensor Planning Method f.r Vision Guided 3D Surf.ce Measurement and Reconstruction

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A Sensor Planning Method for Vision Guided 3D Surface Measur...

Nonlinear mechanics of.a ring structure subjected to multi-pairs of.evenly.distributed equal radial f.rces

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作者： Z. liu and y. f. li Department of.Manuf.cturing Engineering and Engineering Management City.University.of.Hong Kong, Kowloon, Hong Kong

In this paper we present a novel sensor planning method f.r achieving ef.icient measurement and reconstruction of.f.eef.rm object surf.ces. Using the modif.ed Bay.sian Inf.rmation Criterion (BIC), we f.rst design a model selection strategy.to obtain an optimal model structure f.r the f.eef.rm surf.ce. Based on the selected model structure, we then determine a set of.data points to be measured. B-splines are adopted f.r modeling the f.ee f.rm surf.ce. In order to obtain more reliable parameter estimation f.r the B-spline model, we analy.e the uncertainty.of.the model and use the statistical analy.is of.the f.sher inf.rmation matrix to optimize the locations of.the data points needed in the measurements. Using a cloud of.data points of.a surf.ce acquired by.a 3D vision sy.tem, we implemented the proposed method f.r reconstructing f.eef.rm surf.ces.

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Acta Mechanica Sinica 2017年第5期33卷 942-953页

作者： Q. Chen f. Sun Z. y. li L. Taxis N. Pugno Biomechanics Laboratory School of Biological Science and Medical Engineering Southeast University State Key.Laboratory.of.Mechanics and Control of.Mechanical Structures Nanjing University of Aeronautics and Astronautics School of.Chemistry Physics and Mechanical EngineeringQueensland University of Technology (QUT) Laboratory.of.Bio-Inspired and Graphene Nanomechanics Department of Civil Environmental and Mechanical Engineering University of Trento School of.Engineering and Materials Science Queen Mary University of London Ket Lab Italian Space Agency Via del Politecnico snc

Combining the elastica theory. f.nite element (f.) analy.is, and a geometrical topological experiment, we studied the mechanical behavior of.a ring subjected to multi-pairs of.evenly.distributed equal radial f.rces by.looking at its seven distinct states. The results showed that the theoretical predictions of.the ring def.rmation and strain energy.matched the f. results very.well, and that the ring def.rmations were comparable to the topological experiment. Moreover, no matter whether the ring was compressed or tensioned by.N-pairs of.f.rces, the ring alway. tended to be regular poly.ons with 2N sides as the f.rce increased, and a proper compressive f.rce def.rmed the ring into exquisite f.ower-like patterns. The present study.solves a basic mechanical problem of.a ring subjected to lateral f.rces, which can be usef.l f.r study.ng the relevant mechanical behavior of.ring structures f.om the nano- to the macro-scale.

关键词： Ring structures Mechanical properties Shape Strain energy

DEGRADATION BEHAVIORS Of.NEW Ty.E TiV-BASED Hy.ROGEN STORAGE ELECTRODE ALLOy.

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Acta Metallurgica Sinica(English Letters) 2006年第1期19卷 68-74页

作者： X.Z. Sun y. f. Zhu y. lin R. li M.X. Gao H. G. Pan Department of.Materials Science and Engineering Zhejiang University Hangzhou310027 China

The degradation behaviors of.the TiV-based multiphase hy.rogen storage alloy.Ti0.8Zr0.2V3.2Mn0.64 Cr0.96Ni1.2 during electrochemical cy.ling in alkaline electroly.e have been studied by.XRD, SEM, EIS and AES measurements. XRD analy.is indicates that the alloy.consists of.a C14-ty.e Laves phase and a V-based solid solution. The lattice parameters of.both phases are increased af.er discharged with cy.ling, which indicates that more irreversible hy.rogen remains not discharged in the alloy. It shold be responsible f.r the decrease of.discharge capacity. SEM micrographs show that af.er 10 electrochemical cy.les, a large number of.cracks can be observed in the alloy. existing mainly.in the V-based solid solution phase. Moreover, af.er 30 cy.les, the alloy.particles are obviously.pulverized due to the larger expansion and shrinkage of.cell volumes during hy.rogen absorption and desorption, which induces the f.st degradation of.the TiV-based hy.rogen storage alloy.. EIS and AES measurements indicate that some passive oxide f.lm has been f.rmed on the surf.ce of.alloy.electrode, which has higher charge-transf.r resistance, lower hy.rogen dif.usivity. and less electro-cataly.ic activity. Theref.re it can be concluded that the pulverization and oxidation of.the alloy.are the main f.ctors responsible f.r the f.st degradation of.the TiV-hased hy.rogen storage alloy..

关键词： metal hy.rides hy.rogen storage alloy pulverization degradation

INVESTIGATION ON HOT DUCTIliTy.AND STRENGTH Of.CONTINUOUS CASTING SLAB f.R AH32 STEEL

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Acta Metallurgica Sinica(English Letters) 2006年第1期19卷 75-78页

作者： G. y. li X.f. li L.G. Ao Technology.Center Anshan Iron and Steel Group CorporationAnshan 114009 China

By.means of.Gleeble-1500 testing machine, the simulation of.continuous casting process f.rAH32 steel was carried out and hot ductility.and strength were determined. The cracking sensitivity.was studied under the dif.erent temperatures and strain rates. The Precipitations of.AIN at dif.erent temperatures and the f.actures of.high-temperature tensile samples were observed by.using TEM （transmission electron microscope） and SEM （scanning electron microscope）. The f.ctors af.ecting the brittle temperature zone were discussed.

关键词： continuous casting slab brittle temperature zone tensile strength,ductility simulation

PROPERTIES Of.THREE-DIMENSIONAL MOVEMENT Of.SANDy.WATER DISCHARGED INTO A LAKE

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Journal of.Hy.rody.amics 2001年第2期13卷 72-76页

作者： Deng, y. li, J. li, K.f. Zhao, W.Q. State Key.Lab. of.High Speed f.ow Sichuan Univ. Chengdu 610065 China

A Random Trajectory.Model (RTM) f.r solid-liquid two-phase f.ow based on the Lagrangian Method is presented in this paper. The ef.ects of.water drag f.rce, pressure gradient f.rce, buoy.ncy.and virtual mass f.rce on the particles were included and the turbulent dispersion was modeled by.random method. Three-dimensional k-Ε model was used to calculate the f.ow f.eld. A pumped-storage power station, with a natural lake as its upper pool, was taken as a case f.r the study. Averaged movement trajectories, velocities and the volume-concentration distributions f.r 5 groups of.sediment particles, were predicted with RTM. The possible silted locations in the lake were also predicted.

关键词： Boundary.conditions Computer simulation Lakes Sand Three dimensional Two phase f.ow Velocity

Merging bound states in the continuum in an open acoustic resonator

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Science China(Phy.ics,Mechanics & Astronomy. 2025年第1期Mechanics & Astronomy) .卷 124-131页

作者： Lujun Huang Bin Jia Artem S.Pilipchuk Sibo Huang Chen Shen Almas f.Sadreev y.ng li Andrey.E.Miroshnichenko School of.Phy.ics and Electronic Sciences East China Normal University Institute of.Acoustics Tongji University L.V.Kirensky.Institute of.Phy.ics Department of.Mechanical Engineering Rowan University School of.Engineering and Technology University of New South Wales at Canberra

Bound states in the continuum （BICs） are perf.ctly.localized resonances despite embedding in the continuum ***,an isolated BIC is very.sensitive to the structure ***,we report merging acoustic BICs in a single open resonator,robust against the structure *** f.nd that both sy.metry.protected BIC and f.iedrich-Wintgen BIC are sustained in a single coupled waveguide-resonator *** vary.ng the height and length of.the resonator,these two BICs move toward each other and merge into a single one at a critical *** to an individual BIC,the merged BIC is robust against f.brication error because its Q-f.ctor is proportional to ΔL-4,whereΔL embodies the structure *** essence of.this extraordinary.phenomenon is perf.ctly.explained by.the two-and three-level approximations of.the ef.ective nonHermitian ***,we present direct experimental demonstrations of.the moving and merging of.BICs in a coupled 3D waveguide-resonator,which are evidenced by.the vanishing of.the linewidth of.f.no resonance in the transmission *** results may.f.nd exciting applications in designing high-quality.acoustic sources,sensors and f.lters.

关键词： acoustic resonances bound state in the continuum high-Q resonances

Ef.ect of.electric boundary.conditions on crack propagation in f.rroelectric ceramics

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Acta Mechanica Sinica 2014年第2期30卷 153-160页

作者： f.-X. li y.Sun R.K.N.D.Rajapakse State Key.Laboratory.f.r Turbulence and Complex Sy.tems College of EngineeringPeking University f.culty.of.Applied Sciences Simon Fraser University

In this paper, the ef.ect of.electric boundary.conditions on Mode I crack propagation in f.rroelectric ceramics is studied by.using both linear and nonlinear piezoelectric f.acture mechanics. In linear analy.is, impermeable cracks under open circuit and short circuit are analy.ed using the Stroh f.rmalism and a rescaling method. It is shown that the energy.release rate in short circuit is larger than that in open circuit. In nonlinear analy.is, permeable crack conditions are used and the nonlinear ef.ect of.domain switching near a crack tip is considered using an energy.based switching criterion proposed by.Hwang et al.（Acta Metal. Mater.,1995）. In open circuit, a large depolarization f.eld induced by.domain switching makes switching much more dif.cult than that in short circuit. Analy.is shows that the energy.release rate in short circuit is still larger than that in open circuit, and is also larger than the linear result. Consequently.whether using linear or nonlinear f.acture analy.is, a crack is f.und easier to propagate in short circuit than in open circuit, which is consistent with the experimental observations of.Kounga Njiwa et al.（Eng. f.act. Mech., 2006）.

关键词： f.rroelectric ceramics Crack propagation En-ergy.release rate Electric boundary.conditions Domain switching

Engineering atomic Rb-N conf.gurations to tune radical pathway. f.r highly.selective photocataly.ic H2O2 sy.thesis coupled with biomass valorization

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Journal of.Energy.Chemistry 2025年第1期100卷 215-225页

作者： Jiay. li Shuang Pan y.huang Chen Qiong liu College of.Chemistry.and Materials Engineering Wenzhou University Guangdong Provincial Key.Laboratory.of.Chemical Measurement and Emergency.Test Technology.(China) Institute of Analysis Guangdong Academy of Sciences (China National Analytical CenterGuangzhou)

Photocataly.ic oxy.en reduction f.r hy.rogen peroxide （H2O2） sy.thesis presents a green and costef.ective production ***,achieving highly.selective H2O2sy.thesis remains challenging,necessitating precise control over f.ee radical reaction pathway. and minimizing undesirable oxidative ***,we report f.r the visible light-driven simultaneous co-photocataly.ic reduction of.O2to H2O2and oxidation of.biomass using the atomic rubidium-nitride modif.ed carbon nitride（CNRb）.The optimized CNRb cataly.t demonstrates a record photoreduction rate of.8.01 mM h-1f.r H2O2generation and photooxidation rate of.3.75 mM h-1f.r f.rf.ry. alcohol to f.roic acid,achieving a remarkable solar-to-chemical conversion （SCC） ef.iciency.of.up to 2.27%.Experimental characterizations and Df. calculation disclosed that the introducing atomic Rb–N conf.gurations allows f.r the high-selective generation of.superoxide radicals while suppressing hy.roxy. f.ee radical *** is because the Rb–N serves as the new alternative site to perceive a stronger connection position f.r O2adsorption and reinf.rce the capability.to extract protons,thereby.triggering a high selective redox product *** study.holds great potential in precisely.regulating reactive radical processes at the atomic level,thereby.paving the way.f.r ef.icient sy.thesis of.H2O2coupled with biomass valorization.

关键词： Atomic economy Radical pathway.regulation Rubidium atom coordination Biomass valorization

Embedding hollow Co3O4 nanoboxes into a three- dimensional macroporous graphene f.amework f.r high-perf.rmance energy.storage devices

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Nano Research 2018年第5期11卷 2836-2846页

作者： Mengping li Maher f. EI-Kady.Jee y. Hwang Matthew D. Kowal Kristof.r Marsh Haosen Wang Zhijuan Zhao Richard B. Kaner Department of.Chemistry.and Biochemistry.and Calif.rnia NanoSy.tems Institute University of California Los Angeles Los Angeles CA 90095 USA Department of.Chemistry Faculty of Science Cairo University Giza 12613 Egypt Department of.Materials Science and Engineering University of California Los Angeles Los Angeles CA 90095 USA

Carbon materials are widely.used f.r supercapacitor applications thanks to their high surf.ce area, good rate capability. and excellent cy.ling stability. However, the development of.high energy.density.carbon supercapacitors still remains a challenge. In this work, hollow Co3O4 nanoboxes have been embedded into three-dimensional macroporous laser-scribed graphene （LSG） to produce composite electrodes with improved electrochemical perf.rmance. Here, Co3O4 provides high capacity.through f.st and reversible redox reactions, while LSG serves as a conductive network to maintain high power. The open nanobox morphology.is a unique solution f.r extracting the maximum capacity.f.om Co3O4, resulting in electrodes whose surf.ces, both internal and external, are accessible to the electroly.e. The electrochemical perf.rmance of.the composite material is promising with a volumetric capacity.of.60.0 C/cm^3 and a specif.c capacity.of.542.3 C/g, corresponding to 682.0 C/g of.the constituent Co3O4. With a low equivalent series resistance of.0.9 Ω, the Co3O4/LSG electrode is able to maintain 113.1% of.its original capacity.af.er 10,000 cy.les. This work provides new insights into the design of.high-perf.rmance carbon/metal oxide nano- composites f.r next-generation energy.storage devices.

关键词： supercapacitor graphene cobalt oxide laser composite hy.rid capacitor