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Fabrication of a biomimetic controllable adhesive surface by ultraprecision multistep and layered scribing and casting molding

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Science China(Technological Sciences) 2021年第8期64卷 1814-1826页

作者： WANG Wei XIE ZongWu State Key Laboratory of Robotics and system Harbin Institute of TechnologyHarbin150001China

Wedge-shaped microstructures have the ability to reproduce the excellent adhesive properties of geckos’feet because of their unique anisotropic *** particular,the controllability of the wedge-shaped microstructures on adhesion is beneficial to the undisturbed grasp or the capture of space ***,the problem currently remains of how to process it efficiently and with high *** a strategy called ultraprecision multistep and layered scribing is proposed for the manufacture of the biomimetic controllable adhesive *** results show that the metal master mold prepared based on the manufacturing strategy has not only good surface topography but also high reliability and ***,the controllable adhesive surface of 1.96 cm2,fabricated by the proposed manufacturing strategy,has a normal adhesion of 1.012 N,and the corresponding shear friction and adhesion coefficient are 3.105 N and 4.82,***,the controllable adhesive surface has been shown to be approximately superhydrophobic and also to possess the properties of controllable adhesion and dynamic ***,after 250 adhesion-detachment cycles,the normal adhesion and shear friction only decrease by 5%and 3%,*** research realizes an environmentally friendly and efficient method by which to manufacture a durable metal mold for fabricating a biomimetic controllable adhesive surface,laying a foundation for its effective application in the adherence of space-floating targets.

关键词： continuous and tilted wedge-shaped microstructures biomimetic controllable adhesive surface ultraprecision multistep and layered scribing controllable adhesion dynamic adhesion

Hybrid Mapping Method:from Human to Robotic Hands with Dissimilar Kinematics

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Journal of Bionic Engineering 2022年第4期19卷 935-952页

作者： Bingchen Liu Li Jiang Shaowei Fan State Key Laboratory of Robotics and system Harbin Institute of TechnologyHarbin 150080China

Mapping grasps from human to anthropomorphic robotic hands is an open issue in research,because the master hand and the slave hand have dissimilar *** paper proposes a hybrid mapping method to solve this *** the proposed method,fingers in the master and the slave hands are divided into vital and synergic fingers according to their contribution to the grasping *** tip of the vital finger of the master hand is first mapped to that of the slave hand while ensuring that both are in simultaneous contact with the object to be *** postural synergy theory,joints of the other synergic fingers of the slave hand are then used to generate an anthropomorphic grasping configuration according to the shape of the object to be *** this,a human-guided impedance controller is used to reduce the pre-grasping error and realize compliant interaction with the *** proposed hybrid mapping method can not only generate the posture of the humanoid envelope but can also carry out impedance-adaptive *** was evaluated using simulations and an experiment involving an anthropomorphic robotic slave hand.

关键词： Robotic hand Human-in-the-loop Grasping Postural synergy Impedance control

Gelfand–Kirillov Dimensions of the Z^2-graded Oscillator Representations of sl(n)

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Acta Mathematica Sinica,English Series 2015年第6期31卷 921-937页

作者： Zhan Qiang BAI institute of Mathematics Academy of Mathematics and System SciencesChinese Academy of Sciences

We find an exact formula of Gelfand-Kirillov dimensions for the infinite-dimensional explicit irreducible sl（n,F）-modules that appeared in the Z2-graded oscillator generalizations of the classical theorem on harmonic polynomials established by Luo and Xu. Three infinite subfamilies of these modules have the minimal Gelfand-Kirillov dimension. They contain weight modules with unbounded weight multiplicities and completely pointed modules.Service E-mail this articleAdd to my bookshelfAdd to citation managerE-mail AlertRSSArticles by authors

关键词： Gelfand-Kirillov dimension highest-weight module associated variety minimal GKdimension module universal enveloping algebra

Design of heat exchanger network based on entransy theory

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Chinese Journal of Chemical Engineering 2018年第8期26卷 1692-1699页

作者： Li Xia Yuanli Feng Xiaoyan Sun Shuguang Xiang institute of Process system Engineering Ojngdao University of Sdence and Technology Qingdao 266042China

The heat exchanger network(HEN) synthesis problem based on entransy theory is analyzed. According to the characteristics of entransy representation of thermal potential energy, the entransy dissipation represents the irreversibility of the heat transfer process, the temperature difference determines the entransy dissipation, and four HEN design steps based on entransy theory are put forward. The present study shows how it is possible to set energy targets based on entransy and achieve them with a network of heat exchangers by an example of heat exchanger network design for four streams. In order to verify the correctness of the heat exchanger networks design method based on entransy theory, the synthesis of the HEN for the diesel hydrogenation unit is studied. Using the heat exchange networks design method based on entransy theory, the HEN obtained is consistent with energy targets. The entransy transfer efficiency of HEN based on entransy theory is 92.29%, higher than the entransy transfer efficiency of the maximum heat recovery network based on pinch technology.

关键词： Process systems Heat exchanger network synthesis Heat transfer Entransy Energy target Pinch

Optimal trajectory design accounting for the stabilization of linear time-varying error dynamics

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Chinese Journal of Aeronautics 2022年第7期35卷 55-66页

作者： Patrick PIPREK Haichao HONG Florian HOLZAPFEL institute of Flight system Dynamics Technical University of MunichGarching D-85748Germany

This study is dedicated to the development of a direct optimal control-based algorithm for trajectory optimization problems that accounts for the closed-loop stability of the trajectory tracking error dynamics already during the ***,the trajectory is designed such that the Linear Time-Varying(LTV)dynamic system,describing the controller’s error dynamics,is stable,while additionally the desired optimality criterion is optimized and all enforced constraints on the trajectory are *** is achieved by means of a Lyapunov stability analysis of the LTV dynamics within the optimization problem using a time-dependent,quadratic Lyapunov function *** care is taken with regard to ensuring the correct definiteness of the ensuing matrices within the Lyapunov stability analysis,specifically considering a numerically stable formulation of these in the numerical *** developed algorithm is applied to a trajectory design problem for which the LTV system is part of the path-following error dynamics,which is required to be *** main benefit of the proposed scheme in this context is that the designed trajectory trades-off the required stability and robustness properties of the LTV dynamics with the optimality of the trajectory already at the design phase and thus,does not produce unstable optimal trajectories the system must follow in the real application.

关键词： LTV error dynamics LTV stability Optimal control-based LTV stabilization Path-following error controller Trajectory generation Trajectory optimization

Method for Evaluating Digital Video Electromagnetic Information Leakage from Video Cable

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Chinese Journal of Electronics 2021年第5期30卷 978-985页

作者： WANG Sen QIU Yang TIAN Jin AECC Aero Engine Control system institute Electromagnetic Compatibility Laboratory Xidian University

Electromagnetic emissions from electrical information equipment may contain useful information and lead to information leakage. In order to detect the electromagnetic information leakage of digital video cable,a rapid testing method for computer video information leakage detection without reconstructing the displayed image is proposed. In this method, the electromagnetic radiation spectrum of typical image transmitted by HDMI cable is simulated. Then the electromagnetic radiation spectrum of the computer when transmitting the same image as the typical image is obtained by conduction and radiation EMC test methods. Finally, the correlation between the spectrum of simulation and the test spectrum is analyzed, and the correlation coefficient is used to judge whether the computer has produced the electromagnetic leakage of video information. The analysis and test results show that when the correlation coefficient is greater than 0.5, the electromagnetic leakage of computer video information can be judged.

关键词： lead rapid testing method computer video information leakage detection displayed image electrical information equipment evaluating digital video electromagnetic information leakage test spectrum typical image electromagnetic leakage electromagnetic radiation spectrum HDMI cable correlation coefficient electromagnetic emissions digital video broadcasting electromagnetic compatibility digital video cable

Entransy and Exergy Analyses for Optimizations of Heat-Work Conversion with Carnot Cycle

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Journal of Thermal Science 2016年第3期25卷 242-249页

作者： Chul Ho Han Kyoung Hoon Kim Department of Mechanical system Engineering Kumoh National Institute of Technology Department of Mechanical Engineering Kumoh National Institute of Technology

The concept of entransy has been newly proposed in terms of the analogy between heat and electrical conduction and could bc useful in analyzing and optimizing the heat-work conversion systems. This work presents comparative analyses of entransy and exergy for optimizations of heat-work conversion. The work production and heat transfer processes in Carnot cycle system are investigated with the formulations of exergy destruction, entransy loss, work entransy, entransy dissipation, and cfficiencics for both cases of dumping and non-dumping of used source fluid. The effects of source and condensation temperatures on the system performance arc systematically investigated for optimal condition of producing maximum work or work cntransy.

关键词： entransy exergy heat-work conversion Carnot cycle efficiency

Temporal Parameter Optimization in Four-Dimensional Flash Trajectory Imaging

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Chinese Physics Letters 2011年第11期28卷 52-55页

作者： WANG Xin-Wei ZHOU Yan FAN Song-Tao LIU Yu-Liang Optoelectronic system Laboratory Institute of SemiconductorsChinese Academy of SciencesBeijing 100083

In four-dimensional flash trajectory imaging,temporal parameters include time delay,laser pulse width,gate time,pulse pair repetition frequency and the frame rate of CCD,which directly impact on the acquisition of target trajectories over *** propose a method of optimizing the temporal parameters of flash trajectory *** the temporal parameters can be estimated by the spatial parameters of the volumes of interest,target scale and velocity,and target sample *** formulae for optimizing temporal parameters are derived,and the method is demonstrated in an experiment with a ball oscillating as a pendulum.

关键词： flash Flash Temporal

On the horizontal distribution of algal-bloom in Chaohu Lake and its formation process

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Acta Mechanica Sinica 2014年第5期30卷 656-666页

作者： Yuan-Ying Chen Qing-Quan Liu Laboratory for Mechanics in Fluid Solid Coupling system Institute of Mechanics Chinese Academy of Sciences

Based on the remote sensing images of algae, the present work analyzes the horizontal distribution characteristics of algal blooms in Chaohu Lake, China, which also reveals the frequency of algal blooms under different wind directions. Further, an unstructured-grid, three-dimensional finite-volume coastal ocean model （FVCOM） is applied to investigate the wind-induced currents and the transport pro- cess to explain the reason why algal blooms occur at the detected places. We first deduce the primary distribution of biomass from overlaid satellite images, and explain the formation mechanism by analyzing the pollution sources, and simulating the flow field and transportation process under prevailing wind over Chaohu Lake. And then, we consider the adjustment action of the wind on the corresponding day and develop a two-time scale approach to describe the whole formation process of algae horizontal distribution in Chaohu Lake. That is, on the longer time scale, i.e., during bloom season, prevailing wind determines the primary distribution of biomass by inducing the characteristic flow field; on the shorter time scale, i.e., on the day when bloom occurs, the wind force adjusts the primary distribution of biomass to form the final distribution of algal bloom.

关键词： Chaohu Lake Algal bloom Horizontal distri- bution - Wind-driven current Two-time scale process