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Science China Chemistry 2017年第4期60卷 497-503页

作者： Faleh AITal jun gao Department of Physics Engineering Physics and Astronomy Queen's University Kingston Ontario K7L 3N6 Canada

Light-emitting electrochemical cells(LECs) are organic photonic devices based on a mixed electronic and ionic *** active layer of a polymer-based LEC consists of a luminescent polymer,an ion-solvating/transport polymer,and a compatible *** LEC p-n or p-i-n junction is ultimately responsible for the LEC *** LEC junction,however,is still poorly understood due to the difficulties of characterizing a dynamic-junction *** this paper,we present an experimental and modeling study of the LEC junction using scanning optical imaging *** LECs with an interelectrode spacing of 560μm have been fabricated,activated,frozen and scanned using a focused laser *** optical-beam-induced-current(OBIC)and photoluminescence(PL) data have been recorded as a function of beam *** OBIC profile has been simulated in COMSOL that allowed for the determination of the doping concentration and the depletion width of the LEC junction.

关键词： light-emitting electrochemical cell optical beam induced current frozen junction planar LECs polymer p-n junction

Type Synthesis for Bionic Quadruped Walking Robots

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Journal of Bionic Engineering 2015年第4期12卷 527-538页

作者： jun He Feng gao State Key Laboratory of Mechanical System and Vibration Shanghai Jiao Tong University Shanghai 200240 China

Regarding walking robots, biomimetic design has attracted a great deal of attention. Currently, studies have focused mainly on performance analysis and the design of some specific biomimetic walking robots. However, the systematic type synthesis of bionic quadruped robots has seldom been studied. In this paper, a new approach to type synthesis for quadruped walking robots is proposed based on the generalized fimction （Ge） set theory. The current types of typical walking robots are analyzed using the Ge set theory. The research status and existing problems are investigated. The skeletal systems of quadruped mammals are analyzed. The motion characteristics of all joints of quadruped mammals are denoted by 6;F sets. A process of conversion from biological types to serial, parallel and hybrid types is proposed. Limb types in serial, parallel and hybrid topology are synthe- sized. Finally the quadruped robots with serial, parallel and hybrid topology are produced. Two of these types have been suc- cessfully used for the design of walking rescue robots that is suitable for responding to nuclear accidents.

关键词： type synthesis bionic design quadruped robot parallel mechanism GF set

Global Well-posedness for the Fifth-order mKdV Equation

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Acta Mathematica Sinica,English Series 2018年第6期34卷 1015-1027页

作者： Xin jun gao Department of Mathematical Sciences University of Science and Technology of China

We prove the global well-posedness for the Cauchy problem of fifth-order modified Korteweg-de Vries equation in Sobolev spaces H^3（R） for s〉-3/*** main approach is the ＂I-method＂ together with the multilinear mul... 详细信息

关键词： Fifth-order mKdV equation Bourgain space global well-posedness I-method

Influences of Floater Motion on Gap Resonance Triggered by Focused Wave Groups

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China Ocean Engineering 2023年第4期37卷 685-697页

作者： gao jun-liang LYU Jing ZHANG Jian ZANG jun School of Naval Architecture and Ocean Engineering Jiangsu University of Science and TechnologyZhenjiang 212100China Key Laboratory of Port Waterway and Sedimentation Engineering of MOTNanjing Hydraulic Research InstituteNanjing 210029China Key Laboratory of Water Security Guarantee in Guangdong-Hong Kong-Marco Greater Bay Area of Ministry of Water Resources Guangzhou 510611China Centre for Infrastructure Geotechnical and Water Engineering(IGWE)Department of Architecture and Civil EngineeringUniversity of BathBA27AYUK

The current study investigates the hydrodynamic characteristics of gap resonance within a narrow gap formed by two adjacent boxes subjected to incident focused transient wave groups.A two-dimensional(2D)numerical wave tank based on the OpenFOAM package is utilized for this *** weather-side box is fixed while the lee-side box is allowed to heave freely under wave *** effects of the focused wave amplitude and spectral peak period on the wave amplification within the gap,motion of the lee-side box,and wave forces(including horizontal and vertical wave forces)acting on each box are systematically *** comparison,another structural layout consisting of two fixed boxes is also *** results reveal that the release of the heave degree of freedom(DoF)of the lee-side box results in remarkably distinct resonance *** the heave-box system,both its fluid resonant period and the period corresponding to the maximum heave displacement of the lee-side box are significantly larger(i.e.,1.6-1.7 times)than the fluid resonant period of the fixed-box ***,the wave amplification factor inside the gap in the heave-box system is significantly lower than that in the fixed-box *** the variations of the maximum horizontal and vertical wave forces with the spectral peak period and their magnitudes are also significantly different between the two structural systems.

关键词： gap resonance focused waves wave amplification wave forces OpenFOAM

Hydrodynamic Behavior of Fluid Resonance Between Twin Boxes in Moonpool with Various Edge Profiles Under Wave Actions

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China Ocean Engineering 2023年第4期37卷 547-557页

作者： LAN jun-jie JIANG Sheng-chao gao jun-liang Faculty of Vehicle Engineering and Mechanics Dalian University of TechnologyDalian 116024China School of Naval Architecture and Ocean Engineering Jiangsu University of Science and TechnologyZhenjiang 212100China

Fluid resonance in moonpool formed by twin boxes under wave actions is investigated by using a viscous numerical wave flume with ReNormalization Group(RNG)turbulent *** accuracy of the numerical model is validated by available experimental *** types of edge profiles,the sharp edge,concave edge and convex edge are *** simulations show that the normalized resonant amplitude in moonpool decreases with the decrease of moonpool opening or increase of incident wave *** increased reflection coefficients are the major reason for the phenomena,implying less wave energy is able to support the wave resonance in *** the increase of incident wave height,the energy coefficients increase for convex edges around resonant fre-quency,which are oppositely with those of sharp and concave *** flow patterns of the wave resonance in the vicinity of the moonpool entrance are also identified,which are mainly dependent on the edge profiles.

关键词： moonpool wave resonance corner shape RNG turbulent model OpenFOAM® flow pattern

Variational Bayesian labeled multi-Bernoulli filter with unknown sensor noise statistics

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Chinese Journal of Aeronautics 2016年第5期29卷 1378-1384页

作者： Qiu Hao Huang gaoming gao jun College of Electronic Engineering Naval University of Engineering

It is difficult to build accurate model for measurement noise covariance in complex backgrounds. For the scenarios of unknown sensor noise variances, an adaptive multi-target tracking algorithm based on labeled random finite set and variational Bayesian （VB） approximation is proposed. The variational approximation technique is introduced to the labeled multi-Bernoulli （LMB） filter to jointly estimate the states of targets and sensor noise variances. Simulation results show that the proposed method can give unbiased estimation of cardinality and has better performance than the VB probability hypothesis density （VB-PHD） filter and the VB cardinality balanced multi-target multi-Bernoulli （VB-CBMeMBer） filter in harsh situations. The simulations also confirm the robustness of the proposed method against the time-varying noise variances. The computational complexity of proposed method is higher than the VB-PHD and VB-CBMeMBer in extreme cases, while the mean execution times of the three methods are close when targets are well separated.

关键词： Labeled random finite set Multi-Bernoulli filter Multi-target tracking Parameter estimation Variational Bayesian approximation

Particle flters for probability hypothesis density flter with the presence of unknown measurement noise covariance

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Chinese Journal of Aeronautics 2013年第6期26卷 1517-1523页

作者： Wu Xinhui Huang gaoming gao jun College of Electronic Engineering Naval University of Engineering Automatization of Command Institute Academy of Navy Equipment

In Bayesian multi-target fltering,knowledge of measurement noise variance is very *** mismatches in noise parameters will result in biased *** this paper,a new particle flter for a probability hypothesis density（PHD）flter handling unknown measurement noise variances is *** approach is based on marginalizing the unknown parameters out of the posterior distribution by using variational Bayesian（VB）***,the sequential Monte Carlo method is used to approximate the posterior intensity considering non-linear and non-Gaussian *** other particle flters for this challenging class of PHD flters,the proposed method can adaptively learn the unknown and time-varying noise variances while *** results show that the proposed method improves estimation accuracy in terms of both the number of targets and their states.

关键词： Multi-target tracking(MTT) Parameter estimation Probability hypothesis density Sequential Monte Carlo Variational Bayesian method

Stability analysis method considering non-parallelism:EPSE method and its application

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Applied Mathematics and Mechanics(English Edition) 2016年第1期37卷 27-36页

作者： gaotong YU jun gao Jisheng LUO Department of Mechanics Tianjin University

The e-N method is widely used in transition prediction. The amplitude growth rate used in the e-N method is usually provided by the linear stability theory （LST） based on the local parallel hypothesis. Considering the non-parallelism effect, the parabolized stability equation （PSE） method lacks local characteristic of stability analysis. In this paper, a local stability analysis method considering non-parallelism is proposed, termed as EPSE since it may be considered as an expansion of the PSE method. The EPSE considers variation of the shape function in the streamwise direction. Its local characteristic is convenient for stability analysis. This paper uses the EPSE in a strong non-parallel flow and mode exchange problem. The results agree well with the PSE and the direct numerical simulation （DNS）. In addition, it is found that the growth rate is related to the normalized method in the non-parallel flow. Different results can be obtained using different normalized methods. Therefore, the normalized method must be consistent.

关键词： parabolized stability equation (PSE) expansion of PSE (EPSE) linear stability theory (LST) normalized method non-parallel

The energy distribution of a train impact process based on the active-passive energy-absorption method

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Transportation Safety and Environment 2019年第1期1卷 54-67页

作者： Guang-jun gao Key Laboratory of Traffic Safety on the Track(Central South University) Ministry of EducationChangsha 410075China Joint International Research Laboratory of Key Technology for Rail Traffic Safety Central South UniversityChangsha 410075China National&Local Joint Engineering Research Center of Safety Technology for Rail Traffic Vehicle Central South UniversityChangsha 410075China

This paper examines the energy-absorption characteristics of trains for active-passive safety protection.A one-dimensional collision-simulation model of traditional subway vehicles and active-passive safety vehicles was developed based on the multibody dynamics theory using MATLAB simulation *** effectiveness of the simulation model was verified by scaled-collision ***,the energy-absorption characteristics of traditional trains and the active-passive safety trains under different marshalling conditions were *** results showed that as the number of marshalling vehicles increased from 5 to 8,the energy absorption of interface 1 for the active-passive safety trains during the collision was 681 kJ,775 kJ,840 kJ and 901 kJ,and the physical compression of the interface of the head car of the active-passive safety trains was 619 mm,704 mm,764 mm and 816 mm,which was far below the maximum value of 1773 *** head car of the active-passive safety subway vehicles therefore had sufficient energy-absorption ***,to find the maximum safe impact velocity of the active-passive safety trains,the energy distribution of the active-passive safety subway vehicles with 8-car marshalling at different impact velocities was *** was found that the safe impact velocity of an active-passive safety subway vehicle conforming to the requirements of the EN15227 collision standard reached 32 km/h,far exceeding the safe impact velocity of 25 km/h allowed by traditional trains,and representing an increase in the safe impact velocity of 28%.The total collision-energy absorption of the interface of the head car of the active-passive trains was 89.1%higher than that of the traditional trains at the safe impact *** active-passive energy absorption method was therefore effective at improving the crashworthiness of the subway trains.

关键词： active-passive method one-dimensional collision simulation energy distribution collision characteristics

A subduction channel model for exhumation of oceanic-type high-pressure to ultrahigh-pressure eclogite-facies metamorphic rocks in SW Tianshan,China

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Science China Earth Sciences 2016年第12期59卷 2339-2354页

作者： LI JiLei gao jun WANG XinShui Key Laboratory of Mineral Resources Institute of Geology and GeophysicsChinese Academy of Sciences

High-pressure(HP) and ultrahigh-pressure(UHP) eclogites exposed in collisional orogens are widely regarded to record the history of crustal rocks that were subducted to mantle depths and exhumed back to the *** into subduction and exhumation processes plays an important role in understanding the nature and evolution of subduction zones,geodynamics and plate *** contrast to continental-type HP to UHP metamorphic rocks that are dominated by felsic lithology,oceanic-type HP to UHP metamorphic rocks are dominated by mafic eclogites and thus have greater density,and their exhumation needs to overcome large barriers and may involve complicated tectonic *** exhumation of HP to UHP rocks is mainly influenced by the internal buoyancy,however,the external tectonic forces(such as channel flow) also act as effective exhumation drivers;in addition,effects of tectonic settings(such as slab rollback and breakoff) should take into *** HP-UHP metamorphic terrane in Southwestern Tianshan,which mainly comprises of metasediments with interlayered metamafic lenses and blocks,represents a typical accretionary melange associated with deep subduction of oceanic ***,the exhumation mechanisms of these once deeply buried HP-UHP rocks are still under *** on the field occurrences,petrographic features,peak metamorphic P-T conditions and ages of the eclogites/blueschists and their metasedimentary country rocks,a "sediment-type subduction channel" model is advocated in this study to appraise/decipher the formation and evolution of Southwestern Tianshan HP-UHP metamorphic ***-cyclic metamorphic eclogites record the multistage burial-exhumation cycling manipulated by convective flow in a channel-like interface between the plates,giving robust evidence for the presence of a subduction *** addition,this study summarizes some remaining geotectonic problems and research perspectives concerning the Southwestern Tianshan HP-UHP me

关键词： Eclogite High-pressure metamorphism Oceanic crust Exhumation Subduction channel Southwestern Tianshan