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Energy Expenditure of Trotting Gait Under Different Gait Parameters

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Chinese Journal of Mechanical Engineering 2017年第4期30卷 943-950页

作者： Xian-Bao chen Feng Gao State Key Laboratory of Mechanical System and Vibration Shanghai Jiao Tong University Shanghai 200240 China

Robots driven by batteries are clean, quiet, and can work indoors or in space. However, the battery endurance is a great problem. A new gait parameter design energy saving strategy to extend the working hours of the quadruped robot is proposed. A dynamic model of the robot is established to estimate and analyze the energy expenditures during trotting. Given a trotting speed, opti- mal stride frequency and stride length can minimize the energy expenditure. However, the relationship between the speed and the optimal gait parameters is nonlinear, which is difficult for practical application. Therefore, a simplified gait parameter design method for energy saving is pro- posed. A critical trotting speed of the quadruped robot is found and can be used to decide the gait parameters. When the robot is travelling lower than this speed, it is better to keep a constant stride length and change the cycle period. When the robot is travelling higher than this speed, it is better to keep a constant cycle period and change the stride length. Simulations and experiments on the quadruped robot show that by using the proposed gait parameter design approach, the energy expenditure can be reduced by about 54% compared with the 100 mm stride length under 500 mm/s speed. In general, an energy expenditure model based on the gait parameter of the quadruped robot is built and the trotting gait parameters design approach for energy saving is proposed.

关键词： Quadruped robot Energy expenditure Gait Bezier curve

Carbon Dots Intensified Mechanochemiluminescence from Waterborne Polyurethanes as Tunable Force Sensing Materials

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Chinese Journal of Polymer Science 2021年第11期39卷 1403-1411页

作者： Bo-Han Cao Wu chen Wan-Yuan Wei Yu-Lan chen Yuan Yuan Tianjin Key Laboratory of Molecular Optoelectronic Science Department of ChemistryTianjin UniversityTianjin 300354China

1,2-Dioxetane is a well-known chemiluminescent mechanophore allowing real-time monitoring of polymer chain scission,but usually suffers from fluorescence quenching in polar ***,a series of mechanochemiluminescent waterborne polyurethanes/carbon dots composites(WPU-CDs)have been synthesized by incorporating fluorescent CDs to promote the energy transfer process in different *** resulting bulk WPUs,and in particular,their swollen films filled with a large amount of polar solvents(water and ionic liquid)emit intense *** force-induced covalent bond scission and stress distribution within these different WPU-CDs films can be sensitively ***,the ionic liquid containing films exhibited both electrical and luminescent signal changes under stretching,which offer a new kind of force sensor responsive at a broad detecting strain range and for multi-mode strain *** study is expected to stimulate new research endeavors in mechanistic insight on waterborne polyurethanes and the corresponding stretchable sensing devices.

关键词： Polymer mechanochemistry Mechanochemiluminescence Waterborne polyurethane Carbon dots Force sensing

PEO-b-P4VP/Yttrium Hydroxide Hybrid Nanotubes as Supporter for Catalyst Gold Nanoparticles

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Chinese Journal of Chemical Physics 2012年第3期25卷 352-358,374页

作者： Qian Yang Dao-yong chen The State Key Laboratory of Molecular Engineering of Polymers Department of Macromolecular Sci-ence Fudan University Shanghai 200433 China

The adsorption of poly （ethylene oxide）-b-poly（4-vinylpyridine）（PEO-b-P4VP） micelles onto the surface of yttrium hydroxide nanotubes （YNTs） resulted in the hybrid nanotubes with a dense P4VP inner layer and a stretched PEO outer layer surrounding YNTs. The dense P4VP layer was further stabilized by the crosslinking using 1,4-dibromobutane as the crosslinker. Then, the crosslinked hybrid nanotubes （CHNTs） were used as a novel nano supporter for loading the catalyst gold nanoparticles （GNPs） within the crosslinked P4VP layer. The resultant GNPs/CHNTs （GNTs loaded on CHNTs） were applied to catalyze the reduction reaction of p-nitrophenol. The results indicate that this novel nano supporter has advantages such as good dispersity in the suspension, high capacity in loading GNPs （0.87 mmol/g）, high catalytic activity of the loaded GNPs （12.9 μmol-lmin-i）, and good reusability of GNTs/CHNTs.

关键词： Gold nanoparticle catalyst Block copolymer Hybrid nanotube Reusable p-Nitrophenol

A hierarchical multi-UAV cooperative framework for infrastructure inspection and reconstruction

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Control Theory and Technology 2024年第3期22卷 394-405页

作者： Chuanxiang Gao Xinyi Wang Xi chen Ben M.chen Department of Mechanical and Automation Engineering The Chinese University of Hong KongHong KongShatinNTChina

Unmanned aerial vehicles(UAVs)are emerging as a powerful tool for inspections and repair works in large-scale and unstructured 3D infrastructures,but current approaches take a long time to cover the entire *** using UAVs for inspections and repair works puts forward a requirement of improving time efficiency in large-scale and cluster *** paper presents a hierarchical multi-UAV cooperative framework for infrastructure inspection and reconstruction to balance the workload and reduce the overall task completion *** proposed framework consists of two stages,the exploration stage and the exploitation stage,resolving the task in a sequential *** the exploration stage,the density map is developed to update global and local information for dynamic load-balanced area partition based on reconstructability and relative positions of UAVs,and the Voronoi-based planner is used to enable the UAVs to reach their best *** obtaining the global map,viewpoints are generated and divided while taking into account the battery capacity of each ***,a shortest path planning method is used to minimize the total traveling cost of these viewpoints for obtaining a high-quality *** experiments are conducted in both a simulated and real environment to show the time efficiency,robustness,and effectiveness of the proposed ***,the whole system is implemented in real applications.

关键词： Multi-UAV Coverage path planning Infrastructure inspection and reconstruction

化痰通络汤加味方治疗冠心病PCI术后心绞痛痰瘀互结型的临床研究

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广州中医药大学学报 2025年第1期42卷 51-56页

作者：梁志豪陈健广州中医药大学第二附属医院(广州中医药大学同等学力申请硕士学位人员) 广东广州510120 广州中医药大学附属阳江市中医医院广东阳江529500

【目的】探讨化痰通络汤加味方(由半夏、橘红、茯苓、枳实、丹参、川芎、红花、石菖蒲、远志等组成)对冠心病经皮冠状动脉介入(PCI)术后心绞痛痰瘀互结型患者的临床疗效及生活质量的影响。【方法】将广州中医药大学附属阳江市中医医院2... 详细信息

【目的】探讨化痰通络汤加味方(由半夏、橘红、茯苓、枳实、丹参、川芎、红花、石菖蒲、远志等组成)对冠心病经皮冠状动脉介入(PCI)术后心绞痛痰瘀互结型患者的临床疗效及生活质量的影响。【方法】将广州中医药大学附属阳江市中医医院2023年1月至2024年1月期间收治的80例冠心病PCI术后心绞痛痰瘀互结型患者按随机数字表法随机分为对照组和治疗组,每组各40例。对照组给予常规西药治疗,治疗组在对照组的基础上联合化痰通络汤加味方治疗,疗程为1个月。观察2组患者治疗前后中医证候积分、生活质量西雅图心绞痛量表(SAQ)评分的变化情况,并评价2组患者的中医证候疗效和心电图疗效。【结果】(1)SAQ评分方面,治疗后,2组患者的躯体活动受限程度、心绞痛稳定状态、心绞痛发作情况、治疗满意程度、疾病认知程度等各项SAQ评分均较治疗前升高(P0.05)。(4)心电图疗效方面,治疗1个月后,2组患者的心电图均呈现出明显的改善趋势,治疗组的总有效率为87.50%(35/40),对照组为70.00%(28/40);组间比较,治疗组的总体疗效(秩和检验)和总有效率(χ^(2)检验)均明显优于对照组(P<0.05)。【结论】针对冠心病PCI术后心绞痛痰瘀互结型患者,在常规西药治疗基础上联合化痰通络汤加味方治疗,对提高患者临床疗效、改善患者生活质量有积极影响。

关键词：化痰通络汤加味方冠心病PCI术后痰瘀互结型临床疗效生活质量

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Reevaluation of the Holotype of Odorrana schmackeri Boettger,1892(Amphibia:Anura:Ranidae) and Characterization of One Cryptic Species in *** sensu lato through Integrative Approaches

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Asian Herpetological Research 2020年第4期11卷 297-311页

作者： Huijun SHEN Yanjun ZHU Zhen LI Zhuo chen Xiaohong chen College of Life Sciences Henan Normal UniversityXinxiang 453007HenanChina

The Odorrana schmackeri sensu la to is a group of cascade frogs that are widely distributed in southern ***,their taxonomy has long been unresolved and several cryptic species have been reported in the past *** analyses revealed the existence of three sympatrie species(i.c,***,*** and ***2) at the type locality of ***(Gaojiayan Town,Yichang City,Hubei Province,China).However,the lack of an original description for the holotype specimen(SMF6241) of *** poses a confusing and controversial problem in species nomination within this ***,we reevaluate the taxonomic affinities of SMF6241 and examine the distinctness of ***2 based on specimens from the type *** use integrative approaches that combine morphology with 10 microsatellite loci and *** discriminant analysis of morphological characteristics revealed three distinct groupings(i.e.,***,*** and ***2) and attributed SMF6241 to *** clustering analysis of nuclear DNA also identified three corresponding *** addition,analysis of interspecific variation in morphometrics and acoustics showed divergence between ***2 and its sympatric *** lines of evidence from morphological,molecular and bioacoustic approaches suggest the species status of ***2,namely Odorrana ichangensis chen,***,this study resolves the taxonomic assignment of the holotype of *** and provides an example for species delimitation using integrative approaches.

关键词： integrative taxonomy new species Odorrana ichangensis chen sp.nov. Odorrana schmackeri sensu lato reevaluation

NUMERICAL SIMULATION OF VENTILATED CAVITATING FLOW AROUND A 2D FOIL

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Journal of Hydrodynamics 2005年第5期17卷 607-614页

作者： chen Xin LU Chuan-jing Department of Engineering Mechanics Shanghai Jiaotong University Shanghai 200240 China

By using a pressure-based method and the finite volume method in the framework of the time dependent Reynolds-averaged Navier-Stokes equations, the authors studied the unsteady process of ventilated cavities generated forcing air through an orifice in a 2D hydrofoil without natural cavitation physically. The computation was carried out with the Volume Of Fluid （VOF） technique to track the gas-liquid two-phase interface. The results of simulation indicate that the ventilation rate is an important parameter in determining the morphology of cavity. There exists a critical value to convert sheet cavity into supereavity. A high ventilation rate can induce a two phase interface fluctuation and enable the ventilated eavitating flow to present a characteristic of periodicity.

关键词： ventilated cavity re entrant jet interface fluctuation Volume Of Fluid (VOF) techinique

A matrix grammar approach for automatic distributed network resource management

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Frontiers of Computer Science 2013年第4期7卷 583-594页

作者： Weidong MIN Ke chen YongzhenKE School of Computer Science and Software Engineering Tianjin Polytechnic University Tianjin 300387 China

Network resource management is critical to ensure the security and optimal performance of distributed networks and information systems. Existing technologies are not capable of managing large-scale network resources because of a lack of reusability and scalability. This paper presents a matrix grammar approach for automatic distributed network resource management to alleviate these problems. A matrix grammar is proposed using WMI, CIM, and SNMP to manage network resources, and provides a generic mechanism to describe what needs to be managed and how to manage it. A scalable distributed multi-agent architecture for automatic network resource management is proposed, at its core lies a management automation engine consisting of a matrix analyzer and a recipe processor. The proposed solution has been implemented in software and applied in industrial products that achieve good technical and industrial results. It has good extensibility, scalability, ment automation and software and enables network managereusability.

关键词： network management multi-agent matrixgrammar WMI CIM SNMP distributed networks

AN EXPANDED CHARACTERISTIC-MIXED FINITE ELEMENT METHOD FOR A CONVECTION-DOMINATED TRANSPORT PROBLEM

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Journal of Computational Mathematics 2005年第5期23卷 479-490页

作者： Ling Guo Huan-zhen chen Department of Mathematics Shanghai Jiao Tong UniversityShanghai 200030China Department of Mathematics Shandong Normal UniversityJinan 250014China

In this paper, we propose an Expanded Characteristic-mixed Finite Element Method for approximating the solution to a convection dominated transport problem. The method is a combination of characteristic approximation to handle the convection part in time and an expanded mixed finite element spatial approximation to deal with the diffusion part. The scheme is stable since fluid is transported along the approximate characteristics on the discrete level. At the same time it expands the standard mixed finite element method in the sense that three variables are explicitly treated： the scalar unknown, its gradient, and its flux. Our analysis shows the method approximates the scalar unknown, its gradient, and its flux optimally and simultaneously. We also show this scheme has much smaller time-truncation errors than those of standard methods. A numerical example is presented to show that the scheme is of high performance.

关键词： Convection diffusion problems Expanded characteristic mixed finite elementmethod Optimal error estimates Numerical test