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Leader-follower: Human-centered intention-guided controller for novel SuperLimb with application to load-carrying scenarios

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Science China Technological Sciences 2025年第1期 325-338页

作者： qinghua zhang Xianglong LI Hongwei JING Kerui SUN Yuancheng LI Sikai ZHAO Lele LI Haotian JU Ziqi WANG Rui WU Tianjiao ZHENG Jie ZHAO Yanhe ZHU The State Key Laboratory of Robotics and System Harbin Institute of Technology The Learning Algorithms and Systems Laboratory School of Engineeringécole Polytechnique Fédérale de Lausanne

Supernumerary robotic arms(SuperLimb) are a new type of wearable robot that works closely with humans as a third hand to augment human operation capability. Accurate conveyance of wearers' intentions, allocation of roles, and humancentered interaction considerations are the key points in the process of human–SuperLimb collaboration. This paper proposes a human-centered intention-guided leader–follower controller that relies on the dynamic modeling of SuperLimb with application to load-carrying scenarios. The proposed leader–follower controller takes the human as the leader and the SuperLimb as the follower, achieving effective information communication, autonomous coordination, and good force compliance between SuperLimb, humans, and the environment under human safety assurance. First, the human–SuperLimb dynamic system is modeled to achieve force interaction with the environment and wearer. Second, to achieve the precise intention extraction of humans, pose data from five visual odometry sensors are fused to capture the human state, the generalized position, the velocity of hands, and the surface electromyography signals from two myoelectric bracelets sensors are processed to recognize the natural hand gestures during load-carrying scenarios by a designed Swin transformer network. Then, based on the real-time distance detection between human and mechanical limbs, the security assurance and force-compliant interaction of the human–SuperLimb system are realized. Finally, the human hand muscle intention recognition, human–robot safety strategy verification,and comparative load-carrying experiments with and without the proposed method are conducted on the SuperLimb *** showed that the task parameters are well estimated to produce more reasonable planning trajectories, and SuperLimb could well understand the wearer's intentions to switch different SuperLimb actions. The proposed sensor-based human–robot communication framework motivates future studies of o

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Measurement methods of particle size distribution in emulsion polymerization

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Chinese Journal of Chemical Engineering 2021年第11期34卷 1-15页

作者： Shuaifeng zhang qinghua zhang Jianzhuang Shang Zaisha Mao Chao Yang CAS Key Laboratory of Green Process and Engineering Institute of Process EngineeringChinese Academy of SciencesBeijing 100190China School of Chemical Engineering University of Chinese Academy of SciencesBeijing 100049China China National Petroleum&Chemical Planning Institute Beijing 100029China

The particle size distribution of polymer always develops in emulsion polymerization systems,and certain key phenomena/mechanisms as well as properties of the final product are significantly affected by this *** review mainly focuses on the measurement methods of particle size distribution rather than average particle size during the emulsion polymerization process,including the existing off-line,on-line,and in-line measurement ***,the principle,resolution,performance,advantages,and drawbacks of various methods for evaluating particle size distribution are contrasted and ***,several possible development directions or solutions of the in-line measurement technology are explored.

关键词： Particle size distribution Emulsion polymerization Off-line On-line In-line

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Uncertain knowledge graph embedding:an effective method combining multi-relation and multi-path

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Frontiers of Computer Science 2024年第3期18卷 73-89页

作者： Qi LIU qinghua zhang Fan ZHAO Guoyin WANG Key Laboratory of Tourism Multisource Data Perception and Decision Ministry of Culture and TourismChongqing University of Posts and TelecommunicationsChongqing 400065China Chongqing Key Laboratory of Computational Intelligence Chongqing University of Posts and TelecommunicationsChongqing 400065China Chongqing Key Laboratory of Big Data Intelligent Computing Chongqing University of Posts and TelecommunicationsChongqing 400065China

Uncertain Knowledge Graphs(UKGs)are used to characterize the inherent uncertainty of knowledge and have a richer semantic structure than deterministic knowledge *** research on the embedding of UKG has only recently begun,Uncertain Knowledge Graph Embedding(UKGE)model has a certain effect on solving this ***,there are still unresolved *** the one hand,when reasoning the confidence of unseen relation facts,the introduced probabilistic soft logic cannot be used to combine multi-path and multi-step global information,leading to information *** the other hand,the existing UKG embedding model can only model symmetric relation facts,but the embedding problem of asymmetric relation facts has not be *** address the above issues,a Multiplex Uncertain Knowledge Graph Embedding(MUKGE)model is proposed in this ***,to combine multiple information and achieve more accurate results in confidence reasoning,the Uncertain ResourceRank(URR)reasoning algorithm is ***,the asymmetry in the UKG is *** embed asymmetric relation facts of UKG,a multi-relation embedding model is ***,experiments are carried out on different datasets via 4 tasks to verify the effectiveness of *** results of experiments demonstrate that MUKGE can obtain better overall performance than the baselines,and it helps advance the research on UKG embedding.

关键词： knowledge representation uncertain knowledge graph multi-relation embedding uncertain reasoning

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Effects of Load on Dry Sliding Wear Behavior of Mg–Gd–Zn–Zr Alloys

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Journal of Materials Science & Technology 2017年第7期33卷 645-651页

作者： Jie zhang Xiaobo zhang qinghua Liu Shujie Yang zhangzhong Wang School of Materials Science and Engineering Nanjing Institute of TechnologYNanjing 211167China Jiangsu-Key Laboratory of Advanced Structural Materials and APplication Technology Nanjing 211167China

Dry sliding wear tests on as-cast and T6-treated Mg-3Gd-1Zn-0.4Zr（wt%, GZ31K） and Mg-6Gd-1Zn-0.4Zr（wt%, GZ61K） alloys were performed using a ball-on-disk configuration at room temperature. Friction coefficient and wear rate of the alloys were measured under three different applied loads（50 N, 100 N, and 200 N, respectively）. Worn surface morphologies were analyzed using a scanning electron microscope（SEM） coupled with an energy dispersive spectrometer（EDS）. It is found that the friction coefficient of the alloys decreases with increasing load, except the as-cast GZ61 K. The wear rates of the as-cast Mg-Gd-Zn-Zr alloys increase with the increase of the load. However, the wear rates of the T6-treated Mg-Gd-Zn-Zr alloys first increase because of the participation of a large amount of needle-like precipitates, but then decline due to obvious work hardening. The wear mechanisms of abrasion, plastic deformation, oxidation, adhesion and delamination are detected. Abrasion dominates the wear mechanism under the low load; whereas, adhesion is the main wear mechanism under intermediate load, and plastic deformation has great effect on the wear rate under high applied load.

关键词： Magnesium alloys Applied load Wear and friction Wear mechanism

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A modification to the Munk wind-driven ocean circulation theory

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Acta Oceanologica Sinica 2008年第3期27卷 4-10页

作者： zhang qinghua Qu Yuanyuan CHEN Shuiming Key Laboratory of Marine Science and Numerical Modeling of State Oceanic Administration First Institute of Oceanography State Oceanic Administration Qingdao 266061 China Department of Oceanography University of Hawaii at Manoa Honolulu HI96822 USA

In order to fulfill the no-slip condition at the western and eastern boundaries of the ocean basin, introduced ＂effective wind stress＂, which has much larger spatial variations towards the boundaries than in the ocean interior. The effective wind stress can thus be decomposed into spatially slow-varying and fast varying components. Careful scale analysis on the classical Munk winddriven ocean circulation theory, which consists of the interior Sverdrup flow and the western boundary current but of no eastern boundary current, shows that the wind stress curl appearing in the Sverdrup equation must have negligible spatial variations. In the present model the spatially slow-varying component of the wind stress appears in the Sverdrup equation, and the spatially fastvarying component becomes the forcing term of the boundary equations. As a result, in addition to the classical Munk solution the present model has an extra term at the western boundary which （Northern Hemisphere） increases the northward transport as well as the southward return transport, and has a term at the eastern boundary corresponding to the eastern boundary current.

关键词： Munk wind-driven ocean circulation theory,eastern boundary current,western boundary current effective wind stress

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Evaluation of the mold-filling ability of alloy melt in squeeze casting

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Journal of University of Science and Technology Beijing 2006年第1期13卷 60-66页

作者： Haiying zhang Shuming Xing qinghua zhang Jianbo Tan Wen Liu Semisolid Forming Research Center Beijing Jiaotong University Beijing 100044 China Shijiazhuang Locomotive Depot Shijiazhuang 050000 China Department of Material and Engineering Hebei University of Science and Technology Shijiazhuang 050018 China

The mold-filling ability of alloy mclt in squceze casting process was evaluated by means of the maximum length of Archimedes spiral line. A theoretical evaluating model to predict the maximum filling length was built based on the flowing theory of the incompressible viscous fluid. It was proved by experiments and calculations that the mold-tilling pressure and velocity are prominent influencing factors on the mold-filling ability of alloy melt. The mold-filling ability increases with the increase of the mold-filling pressure and the decrease of the proper mold-filling velocity. Moreover, the pouring temperature relatively has less effect on the mold-filling ability under the experimental conditions. The maximum deviation of theoretical calculating values with experimental results is less than 15%. The model can quantitatively estimate the effect of every factor on the mold-filling ability.

关键词： squeeze casting process parameters mold-filling ability theoretical calculation experimental evaluation

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Airfoil Aeroelastic Flutter Analysis Based on Modified Leishman-Beddoes Model at Low Mach Number

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Chinese Journal of Aeronautics 2011年第5期24卷 550-557页

作者： SHAO Song ZHU qinghua zhang Chenglin NI Xianping Science and Technology on Rotorcraft Aeromechanics Laboratory Nanjing University of Aeronautics and Astronautics Nanjing 210016 China

Based on modified Leishman-Beddoes （L-B） state space model at low Mach number （lower than 0.3）, the airfoil aeroelastic system is presented in this paper. The main modifications for L-B model include a new dynamic stall criterion and revisions of normal force and pitching moment coefficient. The bifurcation diagrams, the limit cycle oscillation （LCO） phase plane plots and the time domain response figures are applied to investigating the stall flutter bifurcation behavior of airfoil aeroelastic systems with symmetry or asymmetry. It is shown that the symmetric periodical oscillation happens after subcritical bifurcation caused by dynamic stall, and the asymmetric periodical oscillation, which is caused by the interaction of dynamic stall and static divergence, only happens in the airfoil aeroelastic system with asymmetry. Validations of the modified L-B model and the airfoil aeroelastic system are presented with the experimental airload data of NACA0012 and OA207 and experimental stall flutter data of NACA0012 respectively. Results demonstrate that the airfoil aeroelastic system presented in this paper is effective and accurate, which can be applied to the investigation of airfoil stall flutter at low Mach number.

关键词： low Mach number unsteady aerodynamics airfoil aeroelastic system stall flutter bifurcation

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Conformation preference and related intramolecular noncovalent interaction of selected short chain chlorinated paraffins

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Science China Chemistry 2016年第3期59卷 338-349页

作者： Yuzhen Sun Wenxiao Pan Jianjie Fu Aiqian zhang qinghua zhang State Key Laboratory of Environmental Chemistry and Ecotoxicology Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing100085China Institute of Environment and Health JiangHan UniversityWuhan430056China

Short chain chlorinated paraffins （SCCPs） are not only research focus of environmental issues but also interesting model mol- ecules for organic chemistry which exhibit diverse conformation preference and intramolecular noncovalent interactions （NCIs）. A systematic study was conducted to reveal the conlk）rmation preference and the related intramolecular NCIs in two C^-isomers of SCCPs, 5,5,6,6-tetrachlorodecane and 4,4,6,6-1etrachlorodecane. The overall conformation profile was deter- mined on the basis of relative energies calculated at the MP2/6-311＋＋G（d,p） level with the geometries optimized by B3LYP/6-31 l＋＋G（d,p） method. Then, quantum theory of atoms in molecules （QTAIM） has been adopted to identify the NCls in the selected conformers of the model molecules at both B31~YP/6-31 l＋＋G（d,p） and M06-2X/aug-cc-pvdz level. Different chlorine substitution modes result in varied conformation preference. No obvious gauche effect can be observed tk）r the SCCPs with chlorination on adjacent carbon atoms. The most stable conformer of 5,5,6,6-tetrachlorodecane （tTt） has its three dihedral angles in the T configuration, and there is no intramolecular N（3s found in this molecule. On the contrary, the chlorination on interval carbon atoms favors the adoption of gauche configmation for the H C C CI axis. Not only inlramolecular H-..CI contacts but also H---H interactions have been identified as driving forces to compensate the instability from steric crowding ot the gauche configuration. The gggg and g＇g＇g＇g＇ conformers are the most popular ones, while the populations of tggg and tg＇g＇g＇ conformer are second to those of the gggg and g＇g＇g＇g＇ conformers. Meanwhile, the M06-2X method with large basis sets is preferred for identification of subtle intramolecular NCIs in large molecules like SCCPs.

关键词： short chain chlorinated paraffins intramolecular noncovalent interactions conformation preference chlorination substitution mode

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Unveiling the superior hydrogen evolution reaction activity of 1T-2H MoS_(2)heterointerface by on-chip microdevices

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Nano Research 2025年第1期18卷 149-156页

作者： Bowen Liu Junjie Xiong Shuaishuai Xu Xinying Luo Wenyan Yao Shigang Liu Yuting Du qinghua zhang Yang Gao Bin Wang CAS Key Laboratory of Nanosystem and Hierarchical Fabrication National Center for Nanoscience and Technology(NCNST)Beijing 100190China University of Chinese Academy of Sciences Beijing 100049China School of Materials Science and Engineering China University of Petroleum(East China)Qingdao 266580China Beijing National Laboratory for Condensed Matter Physics Institute of PhysicsChinese Academy of SciencesBeijing 100190China

The identification and clarification of active sites of MoS_(2)have long been the focus of research efforts in hydrogen evolution reaction(HER).In this study,we constructed phase transition-induced 1T-2H MoS_(2)heterojunction via lithium intercalation and evaluated the HER activity using on-chip electrocatalytic microdevices(OCEMs).The heterojunction achieved an overpotential of only 226 mV at a cathodic current density of 10 mA/cm^(2),outperforming the basal planes of 1T and 2H MoS_(2).Furthermore,density functional theory(DFT)calculations demonstrated that the charge redistribution occurs at the 1T-2H MoS_(2)interface with electrons transferring from 1T to 2H MoS_(2),and the interfacial S atom at the top site of 1T MoS_(2)presents the smallest overpotential of 0.37 ***,the interference from highly active edge sites was avoided by precisely exposing specific active areas,quantitatively revealing the catalytic activity order of different types of in-plane MoS_(2)active *** work enables a systematic investigation of the HER activity of various active sites in MoS_(2),laying the foundation for quantitative analysis of activity in other lowdimensional materials.

关键词： on-chip microdevice phase transition heterojunction MoS_(2) hydrogen evolution reaction(HER)

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Degradation data-driven approach for remaining useful life estimation

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Journal of Systems Engineering and Electronics 2013年第1期24卷 173-182页

作者： Zhiliang Fan Guangbin Liu Xiaosheng Si Qi zhang qinghua zhang Department of Automation The Second Artillery Engineering University Department of Automation Tsinghua University Guangdong University of Petrochemical Technology

Remaining useful life （RUL） estimation is termed as one of the key issues in prognostics and health management （PHM）. To achieve RUL estimation for individual equipment, we present a degradation data-driven RUL estimation approach under the collaboration between Bayesian updating and expectation maximization （EM） algorithm. Firstly, we utilize an exponential-like degradation model to describe equipment degradation process and update stochastic parameters in the model via Bayesian approach. Based on the Bayesian updating results, both probability distribution of the RUL and its point estimation can be derived. Secondly, based on the monitored degradation data to date, we give a parameter estimation approach for non-stochastic parameters in the degradation model and prove that the obtained estimation is unique and optimal in each iteration. Finally, a numerical example and a practical case study for global positioning system （GPS） receiver are provided to show that the presented approach can model degradation process and achieve RUL estimation effectively and generate better results than a previously reported approach in literature.

关键词： reliability degradation remaining useful life (RUL) prognostics global positioning system (GPS).

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