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Analytic optimal pose tracking control in close-range proximity operations with a non-cooperative target

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Chinese Journal of Aeronautics 2024年第5期37卷 410-425页

作者： Caisheng WEI Guanhua huang Zeyang yin Qifeng CHEN School of Automation Central South UniversityChangsha 410083China

This paper investigates an analytical optimal pose tracking control problem for chaser spacecraft during the close-range proximity operations with a non-cooperative space target subject to attitude tumbling and unknown orbital ***,the relative translational motion between the orbital target and the chaser spacecraft is described in the Line-of-Sight(LOS)coordinate frame along with attitude quaternion ***,based on the coupled 6-Degree of Freedom(DOF)pose dynamic model,an analytical optimal control action consisting of constrained optimal control value,application time and its duration are proposed via exploring the iterative sequential action control ***,the global closed-loop asymptotic stability of the proposed predictive control action is presented and *** with traditional proximity control schemes,the highlighting advantages are that the application time and duration of the devised controller is applied discretely in light of the influence of the instantaneous pose configuration on the pose tracking performance with less energy consumptions rather than at each sample ***,three groups of illustrative examples are organized to validate the effectiveness of the proposed analytical optimal pose tracking control scheme.

关键词： Optimal control Close-range proximity operation Non-cooperative space target Coupled attitude and orbit control Iterative sequential action control

A multiscale differential-algebraic neural network-based method for learning dynamical systems

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International Journal of Mechanical System Dynamics 2024年第1期4卷 77-87页

作者： yin huang Jieyu Ding College of Computer Science&Technology Qingdao UniversityQingdaoChina School of Mathematics and Statistics Qingdao UniversityQingdaoChina Center for Computational Mechanics and Engineering Simulation Qingdao UniversityQingdaoChina

The objective of dynamical system learning tasks is to forecast the future behavior of a system by leveraging observed ***,such systems can sometimes exhibit rigidity due to significant variations in component parameters or the presence of slow and fast variables,leading to challenges in *** overcome this limitation,we propose a multiscale differential-algebraic neural network(MDANN)method that utilizes Lagrangian mechanics and incorporates multiscale information for dynamical system *** MDANN method consists of two main components:the Lagrangian mechanics module and the multiscale *** Lagrangian mechanics module embeds the system in Cartesian coordinates,adopts a differential-algebraic equation format,and uses Lagrange multipliers to impose constraints explicitly,simplifying the learning *** multiscale module converts high-frequency components into low-frequency components using radial scaling to learn subprocesses with large differences in *** results demonstrate that the proposed MDANN method effectively improves the learning of dynamical systems under rigid conditions.

关键词： dynamical systems learning multibody system dynamics differential-algebraic equation neural networks multiscale structures

A Mean-Field Game for a Forward-Backward Stochastic System With Partial Observation and Common Noise

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IEEE/CAA Journal of Automatica Sinica 2024年第3期11卷 746-759页

作者： Pengyan huang Guangchen Wang Shujun Wang hua Xiao the School of Control Science and Engineering Shandong University the School of Statistics and Mathematics Shandong University of Finance and Economics IEEE the School of Management Shandong University the School of Mathematics and Statistics Shandong University

This paper considers a linear-quadratic(LQ) meanfield game governed by a forward-backward stochastic system with partial observation and common noise,where a coupling structure enters state equations,cost functionals and observation ***,to reduce the complexity of solving the meanfield game,a limiting control problem is *** virtue of the decomposition approach,an admissible control set is *** a filter technique and dimensional-expansion technique,a decentralized control strategy and a consistency condition system are derived,and the related solvability is also ***,we discuss an approximate Nash equilibrium property of the decentralized control ***,we work out a financial problem with some numerical simulations.

关键词： Decentralized control strategy ϵ-Nash equilibrium forward-backward stochastic system mean-field game partial observation

Atomistic study of inverse size effect induced by interfacial plasticity in pearlitic multi-principal element alloy

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Rare Metals 2024年第7期43卷 3341-3355页

作者： Chen Yang Qiao-Sheng Xia Cun-Hong yin Dong-Peng hua College of Mechanical Engineering Guizhou UniversityGuiyang 550025China Key Laboratory of Advanced Manufacturing Technology Ministry of EducationGuizhou UniversityGuiyang 550025China State Key Laboratory of Solidification Processing Center of Advanced Lubrication and Seal MaterialsNorthwestern Polytechnical UniversityXi'an 710072China

Owing to the fine nano-laminated structure,the pearlitic multi-principal element alloy(PMPEA) exhibits excellent mechanical and tribological ***,the incomplete understanding of the size effect of its lamella thickness and the unclear understanding of the plasticity-interface interaction mechanism limit further optimization of *** this study,the FeCoNi/Ni_3Ti interface-mediated plastic deformation behavior in PMPEA and the variation of mechanical and tribological properties with lamella thickness within the nanoscale range using molecular dynamics(MD) simulation were *** results indicate that the mechanical and tribological properties of the PMPEA with lamella thicknesses below 10 nm have a significant inverse size effect,i.e.,the smaller the lamella thickness,the weaker the *** is because the plastic carrier-interface interaction mechanism changes from a strengthening mechanism that hinders dislocations to a weakening mechanism that promotes dislocations with the decreases in the lamella thickness,and the weakening effect becomes more pronounced as the lamella thickness decreases and the number of interfaces *** particular,the deformation behavior of Ni_3Ti lamellae changes from crystal-like to amorphous-like with decreasing ***,in the sample with larger lamella thickness,the occurrence of hierarchical slips in the body-centered cubic(BCC) phase due to the multiprincipal elements effect can better alleviate the stress concentration caused by the dislocation accumulation at the interface,so that the phase interface exhibits outstanding load-bearing *** the dislocation pattern in BCC phase shows a firm high-density cell,which makes the substrate exhibit a stable tribological response.

关键词： Multi-principal element alloy Nano-laminated structure Molecular dynamics simulation Nanoindentation and nanoscratch

Prediction of peritoneal free cancer cells in gastric cancer patients by golden-angle radial sampling dynamic contrast-enhanced magnetic resonance imaging

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2024年第7期25卷 617-627页

作者： Xueqing yin Xinzhong RUAN Yongmeng ZHU Yongfang yin Rui huang Chao LIANG The First Affiliated Hospital of Ningbo University Ningbo 315000China Ningbo Medical Center Lihuili Hospital Ningbo 315000China

Objectiveperitoneal free cancer cells can negatively impact disease progression and patient outcomes in gastric cancer. This study aimed to investigate the feasibility of using golden-angle radial sampling dynamic contrast-enhanced magnetic resonance imaging (GRASP DCE-MRI) to predict the presence of peritoneal free cancer cells in gastric cancer *** enrolled patients were consecutively divided into analysis and validation groups. Preoperative magnetic resonance imaging (MRI) scans and perfusion were performed in patients with gastric cancer undergoing surgery, and peritoneal lavage specimens were collected for examination. Based on the peritoneal lavage cytology (PLC) results, patients were divided into negative and positive lavage fluid groups. The data collected included clinical and MR information. A nomogram prediction model was constructed to predict the positive rate of peritoneal lavage fluid, and the validity of the model was verified based on data from the verification *** was no statistical difference between the proportion of PLC-positive cases predicted by GRASP DCE-MR and the actual PLC test. MR tumor stage, tumor thickness, and perfusion parameter Tofts-Ketty model volume transfer constant (Ktrans) were independent predictors of positive peritoneal lavage fluid. The nomogram model featured a concordance index (C-index) of 0.785 and 0.742 for the modeling and validation groups, *** DCE-MR could effectively predict peritoneal free cancer cells in gastric cancer patients. The nomogram model constructed using these predictors may help clinicians to better predict the risk of peritoneal free cancer cells being present in gastric cancer patients.

关键词： Gastric cancer Magnetic resonance Golden-angle radial sampling Nomogram model Peritoneal free cancer cells

Influence of Transportation Accessibility on Urban-rural Income Disparity and Its Spatial Heterogeneity

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Chinese Geographical Science 2024年第3期34卷 453-467页

作者： huang Xiaoyan KANG Chenchen yin Chun TANG Junqing Northwest Land and Resources Research Center Global Regional and Urban Research InstituteShaanxi Normal UniversityXi’an 710119China School of Resource and Environmental Sciences Wuhan UniversityWuhan 430079China International Institute of Spatial Lifecourse Health(ISLE) Wuhan UniversityWuhan 430079China School of Urban Planning and Design Shenzhen Graduate SchoolPeking UniversityShenzhen 518055China Key Laboratory of Earth Surface System and Human-Earth Relations of Ministry of Natural Resources of China Shenzhen Graduate SchoolPeking UniversityShenzhen 518055China

Transportation accessibility has been treated as an important means of reducing the urban-rural income ***,only a few studies have examined the effects of different types of transportation accessibility on urban-rural income disparity and their spatial *** on data from 285 prefecture-level(and above)Chinese cities in 2000,2005,2010,2015,and 2020,this study uses spatial econometric models to examine how highway accessibility and railway accessibility influence the urban-rural income disparity and to identify their spatial *** result reveals that highway accessibility and railway accessibility have‘coreperiphery’ring-like circle *** urban-rural income disparity exhibits strong spatial clustering *** highway accessibility and railway accessibility are negatively associated with urban-rural income disparity,and the former having a greater effect ***,there is a substitution effect between highway accessibility and railway accessibility in the whole ***,these associations differ in geographic *** the central region,highway accessibility is more important in reducing the urban-rural income disparity,but its effect is weakened with the increase of railway *** the western region,railway accessibility has a larger effect on narrowing the urban-rural income disparity,and this effect is strengthened by the increase of highway *** conclude that improving transportation accessibility is conducive to reducing the urban-rural income disparity but its effect is spatial *** and railways should be developed in a coordinated manner to promote an integrated transport network system.

关键词： transport accessibility income gap regional divergence spatial heterogeneity urban and rural areas China

Spatial construction of ultrasmall Pt-decorated 3D spinel oxidemodified N-doped graphene nanoarchitectures as high-efficiency methanol oxidation electrocatalysts

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Rare Metals 2024年第1期43卷 186-197页

作者： Qi Zhang Min-Min Yan Wen-Fa Du Chen-Yu yin Jian Zhang Lu Yang Yun-Qing Kang Hai-Yan He hua-Jie huang College of Mechanics and Materials Hohai UniversityNanjing 210098China New Energy Technology Engineering Lab of Jiangsu Province College of ScienceNanjing University of Posts&Telecommunications(NUPT)Nanjing 210023China International Center for Materials Nanoarchitectonics(WPIMANA) National Institute for Materials ScienceTsukuba 305-0044IbarakiJapan

Direct methanol fuel cell technology recently becomes the focus of both academic and engineering circles,which stimulates the exploitation and utilization of advanced electrode catalysts with high activity and long ***,we demonstrate a robust bottom-up approach to the spatial construction of three-dimensional(3D) spinel manganese-cobalt oxide-modified N-doped graphene nanoarchitectures decorated with ultrasmall Pt nanoparticles(Pt/MnCo_(2)O_(4)-NG) via a controllable selfassembly *** incorporation of MnCo_(2)O_(4)nanocrystals provides abundant hydroxyl sources to promote the oxidative removal of CO-like byproducts on Pt sites,while the existence of 3D porous N-doped graphene networks facilitates the transportation of both ions and electrons in the hybrid system,thus giving rise to remarkable synergetic coupling effects during the methanol oxidation ***,the optimized Pt/MnCo_(2)O_(4)-NG nano architecture expres ses exceptional electrocatalytic properties with a large electrochemically active surface area of 99.5 m^(2)·g^(-1),a high mass activity of1508.3 mA·mg^(-1),strong toxicity resistance and reliable long-term durability,which have obvious competitive advantages over those of conventional Pt/carbon black,Pt/carbon nano tube,Pt/graphene,and Pt/N-doped graphene catalysts with the same Pt usage.

关键词： Platinum MnCo_(2)O_(4) 3D graphene Electrocatalysts Methanol oxidation

Accurate characterization of bubble mixing uniformity in a circular region using computational geometric theory

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Particuology 2024年第3期86卷 149-159页

作者： Hui Sun Jianxin Xu Shibo Wang Guangcheng Cai hua Wang Wuliang yin State Key Laboratory ofComplex Nonferrous Metal Resources Clean Utilization Kunming University ofScience and TechnologyKunming650093China bFaulty of Metallurgical and Energy Engineering Kunming University ofScience and TechnologyKunming650093China Faculty of Science Kunming University ofScience and TechnologyKunming650500China Department of Elec.and Electronic Engineering.University of Manchester ManchesterM139PL UK

The present study proposes a novel method based on the geometric theory for measuring the distribution of bubble swarms in the circular region of a direct-contact heat *** was determined that the mixing is uniform when the average distance between the bubble swarms in the unit circular region is approximately 0.9054,which is the standard reference *** effect of sample size(i.e.,the number of bubbles)on mixing uniformity was investigated to determine the optimal sample *** was verified that the metric's accuracy and stability were higher with a sample size of ***,it was proposed to increase the sample size by filling irregular bubbles using a segmentation method,which enabled a further accurate assessment of the mixing *** mixing uniformity of bubble swarms in the circular region and its maximum internal connection with the square region was accurately *** was revealed that the relative average error increased by approximately 3.47% due to information *** proposed method was demonstrated to be rotationally *** present study provided novel insights into evaluating mixing uniformity,which would guide enhanced heat transfer and the effective evaluation of the spatiotemporal characteristics of transient mixing in circular regions or the cross-sections of chemical transport pipelines.

关键词： Direct-contact heat exchanger Circular region Bubble swarm Distribution uniformity AD-Circle method

ON MONOTONE TRAVELING WAVES FOR NICHOLSON'S BLOWFLIES EQUATION WITH DEGENERATE p-LAPLACIAN DIFFUSION

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Acta Mathematica Scientia 2024年第4期44卷 1550-1571页

作者： Rui huang Yong WANG Zhuo yin School of Mathematical Sciences South China Normal UniversityGuangzhou 510631China

We study the existence and stability of monotone traveling wave solutions of Nicholson's blowflies equation with degenerate p-Laplacian *** prove the existence and nonexistence of non-decreasing smooth traveling wave solutions by phase plane analysis ***,we show the existence and regularity of an original solution via a compactness ***,we prove the stability and exponential convergence rate of traveling waves by an approximated weighted energy method.

关键词： degenerate diffusion p-Laplacian traveling waves stability