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Hierarchical path planning for multi-arm spacecraft with general translational and rotational locomotion mode

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Science China(Technological Sciences) 2023年第4期66卷 1180-1191页

作者： YUE ChengFei LIN Tao ZHANG Xiao CHEN XueQin CAO XiBin institute of Space Science and applied Technology Harbin Institute of Technology ShenzhenShenzhen 518055China Research Center of the Satellite Technology Harbin Institute of TechnologyHarbin 150001China

On-orbit construction and maintenance technology will play a significant role in future space *** dexterous multifunctional spacecraft equipped with multi-arm,for instance,Spider Fab Bot,has attracted a great deal of focus due to its versatility in completing these *** such engineering practice,point-to-point moving in a complex environment is the fundamental *** paper investigates the three-dimensional point-to-point path planning problem,and a hierarchical path planning architecture is developed to give the trajectory of the multi-arm spacecraft effectively and *** the proposed 3-level architecture,the high-level planner generates the global constrained centric trajectory of the spacecraft with a rigid envelop assumption;the middle-level planner contributes the action sequence,a combination of the newly developed general translational and rotational locomotion mode,to cope with the relative position and attitude of the arms about the centroid of the spacecraft;the low-level planner maps the position/attitude of the end-effector of each arm from the operational space to the joint space ***,the simulation experiment is carried out,and the results verify the effectiveness of the proposed three-layer architecture path planning strategy.

关键词： multi-arm spacecraft path planning hierarchical architecture locomotion mode translational locomotion rotational locomotion

Controllability of Boolean control networks with multiple time delays in both states and controls

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Frontiers of Information Technology & Electronic Engineering 2023年第6期24卷 906-915页

作者： Yifeng LI Lan WANG National Center for applied mathematics in Chongqing Chongqing Normal UniversityChongqing 401331China institute of mathematics School of Mathematical SciencesNanjing Normal UniversityNanjing 210023China

In this paper,the problem of controllability of Boolean control networks(BCNs)with multiple time delays in both states and controls is ***,the controllability problem of BCNs with multiple time delays in controls is *** this controllability problem,a controllability matrix is constructed by defining a new product of matrices,based on which a necessary and sufficient controllability condition is ***,the controllability of BCNs with multiple time delays in states is studied by giving a necessary and sufficient ***,based on these results,a controllability matrix for BCNs with multiple time delays in both states and controls is proposed that provides a concise controllability ***,two examples are given to illustrate the main results.

关键词： Boolean control networks Semi-tensor product of matrices Controllability Time delay

An Adaptive Moving Mesh Method for the Five-Equation Model

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Communications in Computational Physics 2022年第6期32卷 189-221页

作者： Yaguang Gu Dongmi Luo Zhen Gao Yibing Chen School of Mathematical Sciences Ocean University of ChinaQingdaoShandongChina College of Oceanic and Atmospheric Sciences Ocean University of ChinaQingdaoShandongChina institute of applied Physics and Computational mathematics BeijingChina

The five-equation model of multi-component flows has been attracting much attention among researchers during the past twenty years for its potential in the study of the multi-component *** this paper,we employ a second order finite volume method with minmod limiter in spatial discretization,which preserves local extrema of certain physical quantities and is thus capable of simulating challenging test problems without introducing non-physical ***,to improve the numerical resolution of the solutions,the adaptive moving mesh strategy proposed in[Huazhong Tang,Tao Tang,Adaptive mesh methods for one-and two-dimensional hyperbolic conservation laws,SINUM,41:487-515,2003]is ***,the proposed method can be proved to be capable of preserving the velocity and pressure when they are initially constant,which is essential in material interface ***,several classical numerical examples demonstrate the effectiveness and robustness of the proposed method.

关键词： Multi-component flows five-equation model finite volume method minmod limiter adaptive moving mesh method stiffened gas EOS

Electron heat conduction under non-Maxwellian distribution in hohlraum simulation

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Electron heat conduction under non-Maxwellian distribution i...

Graph Theory Methods for Decomposition w.r.t. Outputs of Boolean Control Networks

第七届全国青年计算物理学术会议

作者：霍文义蓝可古培俊勇珩曾清红 institute of applied Physics and Computational mathematics

An electron transport model based on the non-Maxwellian distribution f0 ∝ e-vm(NM model),caused by the inverse bremsstrahlung heating, is used in 1-D plane target and 2-D hohlraum simulations. In the NM model, the electron heat flux depends not only on the gradient of electron temperature Tebut also on the gradients of electron number density and the index m. From 1-D simulations, the spatial distribution of Teis dune-like and Tedecreases obviously in the flux-heated region, which is very different from the flat profile obtained by using the flux limit model (FL model) but similar to the experimental observations [Gregori et al., Phys. Rev. Lett. 92, 205006 (2004)] and the nonlocal results [Rosen et al., High Energy Density Phys. 7, 180 (2011)]. The reason which causes the dune-like profile of Teis discussed in the paper. From 2-D hohlraum simulations, the NM results of the plasma status, the emission peak and profile inside hohlraum are very different from the FL model results. Finally, it is hard to use an average flux limiter in the FL model to obtain the same hohlraum plasma status and emission with those under the NM model.

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Journal of Systems Science & Complexity 2017年第3期30卷 519-534页

作者： ZOU Yunlei ZHU Jiandong College of Mathematical Sciences Yangzhou University institute of mathematics School of Mathematical Sciences Nanjing Normal University

This paper focuses graph theory method for the problem of decomposition w.r.t. outputs for Boolean control networks(BCNs). First, by resorting to the semi-tensor product of matrices and the matrix expression of BCNs, the definition of decomposition w.r.t. outputs is introduced. Second, by referring to the graphical structure of BCNs, a necessary and sufficient condition for the decomposition w.r.t. outputs is obtained based on graph theory method. Third, an effective algorithm to realize the maximum decomposition w.r.t. outputs is proposed. Finally, some examples are addressed to validate the theoretical results.

关键词： Boolean control network decomposition w.r.t outputs semi-tensor product.

Combination of on-line preconcentration by di(2-ethylhexyl) phosphoric acid resin in the presence of complexing agent with microwave plasma-atomic emission spectrometry for the determination of rare earths

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Journal of Rare Earths 2010年第S1期28卷 79-82页

作者：赵晓伟孔祥飞贾琼周伟红曲晓刚 College of Chemistry Jilin University Changchu n institute of applied Chemistry Chinese Academy of Sciences

The adsorption of rare earths,lanthanum,cerium,neodymium,and yttri um by di(2-ethylhexyl) phosphoric acid(D2EHPA) resin in the presence of a compl exing agent,EDTA,was investigated. Flow injection was selected as the injectin g method. Various parameters,sample pH,sample loading time,sample flow rate,EDTA concentration,EDTA flow rate,eluent concentration,and eluent flow rate,were studied and optimized. Under the optimum conditions,the method allowed the determination of rare earths with detection limits of 1.09 μg/L(lanthanum),3 .31 μg/L(cerium),2.05 μg/L(neodymium),and 1.25 μg/L(yttrium) . High repea tabilities were obtained for all the four rare earths(RSDapplied to the determination of the rare earths in water samples with a recovery range of 95.8%-103.3%.

关键词： di(2-ethylhexyl) phosphoric acid resin complexing agent rare earths

Experimental investigation of the effect of Reynolds number on flow structures in the wake of a circular parachute canopy

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Acta Mechanica Sinica 2014年第3期30卷 361-369页

作者： Zhe-Yan Jin Sylvio Pasqualini Bo Qin School of Aerospace Engineering and applied Mechanics Tongji University institute of Unmanned Aircraft System Beihang University

In the present study, an experimental study was conducted to characterize the effect of Reynolds number on flow structures in the turbulent wake of a circular parachute canopy by utilizing stereoscopic particle image velocime- try （Stereo-PIV） technique. The parachute model tested in the present study was attached by 28 nylon suspension lines and placed horizontally at the test section center of the wind tunnel. The obtained results showed that with the in- crease of Reynolds number, the intensities of the vortices near the downstream region of the canopy skirt were found to increase accordingly. However, the increase of Reynolds number did not result in a significant change in ensemble- averaged normalized x-component of the velocity, ensembleaveraged normalized vorticity, normalized Reynolds stress, and normalized turbulent kinetic energy distributions in the turbulent wake of the circular parachute canopy. The obtained results are very useful to further our understanding about the unsteady aerodynamics in the wake of flexible circular parachute canopies and to constitute a reference for CFD computation.

关键词： Stereo-PIV Circular parachute - Canopy Flexible Turbulent wake

Quantum Entropic Dynamics of a Trapped Ion in a Standing Wave

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Chinese Physics Letters 2000年第12期17卷 885-887页

作者： FANG Mao-Fa ZHOU Peng S.Swain Department of Physics Hunan Normal UniversityChangsha410081 Anhui institute of Optics and Fine Mechanics Chinese Academy of SciencesHefei 230031 Department of applied mathematics and Theoretical Physics The Queens University of BelfastBelfast BT7 lNNUK

By performing a unitary transformation,we transform the Hamiltonian of the trapped ion in any position of standing wave to that of the normal Jaynes-Cummings model in ionic bare basis and we obtain a general evolution operator of the trapped ion *** study the quantum entropic dynamics of the phonons and trapped *** results show that,when the trapped ion is located at the node of standing wave,the quantum entropic dynamics of phonons and trapped ion are the same as the one of the field in the Jaynes-Cummings *** the trapped ion deviates from the node of standing wave,the entropies of the phonons and ion keep their maximum value except at the initial stage,and the phonons and trapped ion become extremely entangled.

关键词： Quantum trapped Standing

Backward Secondary Electron Emission Yield of Thick Targets Induced by MeV Ions

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Chinese Physics Letters 2000年第9期17卷 691-693页

作者： JIANG Lei ZHAO Guo-qing ZHOU Zhu-Ying applied Ion Beam Physics Laboratory Institute of Modern PhysicsFudan UniversityShanghai 200433

The backward secondary electron emission yields of MeV ions(H^(+),He^(+),He^(++),Cl,Si,and Cu)impinging on thick carbon and gold targets are *** measured results for H+(1MeV≤E≤5MeV)on carbon are proportional to the electronic stopping *** experimental data and fitting formula of yields for H+(1 MeV≤E≤4.5MeV)impacting Au are compared with the theoretical *** influence of the collective field and the charge state of ions on the secondary electron emission yield is discussed.

关键词： collective backward Electron