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Improving Kinematic Flexibility and Walking Performance of a Six-legged Robot by Rationally Designing Leg Morphology

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Journal of Bionic Engineering 2019年第4期16卷 608-620页

作者： jie Chen Zhongchao Liang Yanhe Zhu jie zhao School of Mechanical Engineering and Automation Northeastern UniversityShenyang 110819China State Key Laboratory of Robotics and System Harbin Institute of TechnologyHarbin 150001China

This paper explores the design of leg morphology in a six-legged *** by nature,where animals have different leg morphology,we examined how the difference in leg morphology influences behaviors of the *** this end,a systematic search was conducted by scanning over the parameter space consisting of default angles of leg joints of the six-legged robot,with two main objectives:to maximize the kinematic flexibility and walking performance of the *** show that(1)to have a high kinematic flexibility with both the torso and swing legs,the femur segment should tilt downwards by 5°-10°and the tibia segment should be vertically downwards or with a slight inward tilt;(2)to achieve relatively energy-efficient and steady walking,the tibia segment should be approximately vertically downwards,with the femur segment tilting upwards to lower the torso *** results of this study suggest that behaviors of legged robots can be passively enhanced by careful mechanical design choices,thereby leading to more competent legged machines.

关键词： six-legged robot leg morphology kinematic flexibility walking performance

Numerical evaluation of tandem rotor for highly loaded transonic fan

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航空动力学报 2011年第6期26卷 1352-1361页

作者： zhao Bin LIU Bao-jie School of Jet Propulsion Beijing University of Aeronautics and Astronautics Beijing 100191 China

Transonic tandem rotor was designed for highly loaded fan at a corrected tip speed of 381 m/s and another conventional rotor was designed as a baseline to evaluate the loading superiority of tandem rotor with three-dimensional(3-D) numerical *** aft blade solidity and its impact on total loading level were studied in *** result indicates that tandem rotor has potential to achieve higher loading level and attain favorable aerodynamic performance in a wide range of loading coefficient 0.55~0.68,comparing with the conventional rotor which produced a total pressure ratio of 2.0 and loading coefficient of 0.42.

关键词： transonic fan tandem rotor highly loaded loading coefficient numerical simulation

Essential Protein Prediction Based on Shuffled Frog-Leaping Algorithm

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Chinese Journal of Electronics 2021年第4期30卷 704-711页

作者： YANG Xiaoqin LEI Xiujuan zhao jie School of Computer Science Shaanxi Normal University

Essential proteins are integral parts of living organisms. The prediction of essential proteins facilitates to discover disease genes and drug targets. The prediction precision and robustness of most of existing identification methods are not satisfactory. In this paper,we propose a novel essential proteins prediction method(EPSFLA), which applies Shuffled frog-leaping algorithm(SFLA), and integrates several biological information with network topological structure to identify essential ***, the topological property and several biological properties(function annotation, subcellular localization,protein complex, and orthology) are integrated and utilized to weight protein-protein interaction *** the position of a frog is encoded and denotes a candidate essential protein set. The frog population continuously evolve by means of local exploration and global exploration until termination criteria for algorithm are satisfied. Finally, those proteins contained in the best frog are regarded as predicted essential proteins. The experimental results show that EPSFLA outperforms some well-known prediction methods in terms of various *** proposed method aims to provide a new perspective for essential protein prediction.

关键词： Computational biology Essential protein Protein-protein interaction(PPI) network Shuffled frog leap algorithm

Double-decoupled inverse design of natural laminar flow nacelle under transonic conditions

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Chinese Journal of Aeronautics 2023年第6期36卷 1-18页

作者： Heng ZHANG jie LI zhao YANG School of Aerospace Engineering Tsinghua UniversityBeijing 100084China School of Aeronautics Northwestern Polytechnical UniversityXi’an 710072China

The inverse design based on the pressure distribution is an essential approach to realize the improvement of Natural Laminar Flow(NLF) performance for nacelles. However, the direct definition of target pressure distribution at design point is challenging for the dilemma to consider the constraints of shock wave and laminar flow at the same time. In addition, the universality of method will be limited when the inverse design is strongly coupled with the solver. Thus, a double-decoupled methodology based on the relationship of pressure distributions between design and off-design points is proposed in this paper, which realizes the decoupling of constraints in shock wave and laminar flow on target pressure distribution as well as the decoupling of flow field solution and inverse design method. Aimed at an isolated flow-through-nacelle of high bypass ratio, the target pressure distribution with appropriate favorable gradient and shock-free feature is defined according to physical principles at the off-design point of Ma = 0.80 while the transonic and laminar performance are examined at the design point of Ma = 0.85. The solution of flow field is based on γ-Re_(θ) transition model and the inverse design is based on residual-correction method. With the inverse design starting from off-design point, the performance of shock wave and laminar flow at design point are both improved. The local shock wave after the lip of nacelle is eliminated effectively while the streamwise length of laminar flow region is doubled and exceeds to 30% of the chord length. The percentage of drag reduction for outboard surface is 12.7% for friction drag, 7.8%for pressure drag and 10.5% for total drag. The effects of inverse design on the process of transition are analyzed with detailed flow features. The robustness of laminar flow is examined under different variation factors of freestream which are deviated from the design point.

关键词： Drag reduction Inverse design method Nacelle Natural laminar flow Transonic

Transforming bulk alkenes and alkynes into fine chemicals enabled by single-atom site catalysis

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Nano Research 2022年第9期15卷 7840-7860页

作者： Ping Guo Hongyuan Liu jie zhao Key Laboratory for Advanced Materials and Joint International Research Laboratory of Precision Chemistry and Molecular Engineering Feringa Nobel Prize Scientist Joint Research CenterFrontiers Science Center for Materiobiology and Dynamic ChemistrySchool of Chemistry and Molecular EngineeringEast China University of Science and TechnologyShanghai 200237China Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical Biology(Ministry of Education) Department of ChemistryTsinghua UniversityBeijing 100084China

The addition and substitution reactions across a variety of alkenes and alkynes have been playing an important role in organic *** particular,catalyses enabled by homogeneous complexes as well as heterogenous nanomaterials have been much received attentions over *** with these blooming progresses in these fields,single-atom site catalysts(SACs)exhibit outstanding performances in terms of reactivity and selectivity,thus providing a new powerful strategy to upgrade these bulk ***,we summarize the reactions of alkenes and alkynes enabled by SACs,in which catalytic hydrogenation,hydrosilylation,hydroboration,hydroformylation,and cross coupling have been ***,preparations and fine structures of the corresponding SACs have been described,therefore providing a better understanding and overview to address the origin of catalytic activity in the reported examples.

关键词： single-atom site catalysts(SACs) alkenes alkynes

Optimal location of a particulate matter sampling head outside an unmanned aerial vehicle

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Particuology 2017年第3期15卷 153-159页

作者： Jing Zhang Yaqin Ji jie zhao Jingbo zhao College of Environmental Science and Engineering Nankai University Tianjin 300071 China

Particulate matter （PM） has received considerable attention from scientists because of its adverse effects on human health. Unmanned aerial vehicles （UAVs） offer a new approach for monitoring PM in inaccessi- ble or dangerous locations. Computational fluid dynamics software and a wind-tunnel experiment were used to evaluate the flow field at 20, 30, and 40m/s, as well as the trajectories of PM1, PM2.5, and PMlo. The numerical simulation results show that the PM sampling head can be installed 440-680 mm from the UAV nose, and at least 130, 135, and 145 mm below the horizontal axis for free stream velocities of 20, 30, and 40 m/s, respectively. Wind-tunnel experiment results confirmed and improved on those numer- ical results, and showed that the PM sampling head can be 500-600 mm aft the UAV nose, at vertical distances below the horizontal axis of at least 138 mm for 500-550 mm, and 157 mm for 550-600 mm. In addition, sampling points can be located at either side of the optimal ranges, not only on the center line or the UAV.

关键词： Particulate matter CFD Wind tunnel Optimal location

Promising Organic Materials Screened out by Computational Strategy Towards Electrically Pumped Lasers

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Chemical Research in Chinese Universities 2020年第6期36卷 1149-1150页

作者： LIANG jie zhao Yongsheng Key Laboratory of Photochemistry Institute of ChemistryChinese Academy of SciencesBeijing 100190P.R.China School of Chemical Sciences University of Chinese Academy of SciencesBeijing 100049P.R.China

Although many efforts have been attempted by scientists worldwide,electrically pumped organic lasing emission still remains as one of the greatest challenges in the field of ***,Shuai and coworkers proposed a computational strategy based on time-dependent density ftinctional theory(TDDFT),offering a new avenue to the molecule design and materials selection towards electrically pumped organic *** material property prediction package(MOMAP)previously developed by this group was utilized to obtain photophysical parameters of various organic lasing molecules,and to estimate whether they can fulfill the criteria for electrical *** systematic calculation and evaluation,three compounds,BP3T,CzPVSBF,and BSBCz were screened out as promising candidates,revealing the reliability and universality of the proposed computational *** work has been published online in the Nature Communications in September 8,2020.

关键词： pumped pumping lasing

A Parameterization of the Canonical Bases of Affine Modified Quantized Enveloping Algebras

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Chinese Annals of Mathematics,Series B 2016年第2期37卷 235-258页

作者： jie XIAO Minghui zhao Department of Mathematical Sciences Tsinghua University College of Science Beijing Forestry University

For a symmetrizable Kac-Moody Lie algebra g, Lusztig introduced the corresponding modified quantized enveloping algebra˙U and its canonical basis˙B given by Lusztig in 1992. In this paper, in the case that g is a symmetric Kac-Moody Lie algebra of finite or affine type, the authors define a set M which depends only on the root category R and prove that there is a bijection between M and ˙B, where R is the T^2-orbit category of the bounded derived category of the corresponding Dynkin or tame quiver. The method in this paper is based on a result of Lin, Xiao and Zhang in 2011, which gives a PBW-type basis of U^+.

关键词： Ringel-Hall algebras Root categories Modified quantized enveloping algebras Canonical bases

Statistical study of emerging flux regions and the response of the upper atmosphere

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Research in Astronomy and Astrophysics 2012年第12期12卷 1681-1692页

作者： jie zhao Hui Li Purple Mountain Observatory Chinese Academy of SciencesNanjing 210008China Key Laboratory of Dark Matter and Space Astronomy Chinese Academy of SciencesNanjing 210008China

We statistically study the properties of emerging flux regions（EFRs）and response of the upper solar atmosphere to the flux emergence using data from the Helioseismic and Magnetic Imager and the Atmospheric Imaging Assembly onboard the Solar Dynamics *** including total emerged flux,flux growth rate,maximum area,duration of the emergence and separation speed of the opposite polarities are adopted to delineate the properties of *** response of the upper atmosphere is addressed by the response of the atmosphere at different wavelengths （and thus at different temperatures）.According to our results,the total emerged fluxes are in the range of（0.44-11.2）×1019 Mx while the maximum area ranges from 17 to 182 *** durations of the emergence are between 1 and 12 h,which are positively correlated to both the total emerged flux and the maximum *** maximum distances between the opposite polarities are 7-25 arcsec and are also positively correlated to the *** separation speeds are from 0.05 to 1.08 km s-1,negatively correlated to the *** derived flux growth rates are（0.1-1.3）×1019 Mx h-1, which are positively correlated to the total emerging *** upper atmosphere first responds to the flux emergence in the 1600Achromospheric line,and then tens to hundreds of seconds later,in coronal lines,such as the 171（T=105.8 K）and 211（T=106.3 K）lines almost simultaneously,suggesting the successive heating of the atmosphere from the chromosphere to the corona.

关键词： Sun:magnetic fields-Sun:UV radiation-Sun:corona