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Function-oriented optimization design method for underactuated tendon-driven humanoid prosthetic hand

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Frontiers of Mechanical Engineering 2022年第3期17卷 75-89页

作者： Yue ZHENG Xiangxin LI lan tian Guanglin LI CAS Key Laboratory of Human-Machine Intelligence-Synergy Systems Shenzhen Institutes of Advanced Technology(SIAT)Chinese Academy of Sciences(CAS)Shenzhen518055China Shenzhen College of Advanced Technology University of Chinese Academy of SciencesShenzhen518055China SIAT Branch Shenzhen Institute of Artificial Intelligence and Robotics for SocietyShenzhen518055China Guangdong-Hong Kong-Macao Joint Laboratory of Human-Machine Intelligence-Synergy Systems Shenzhen518055China

The loss of hand functions in upper limb amputees severely restricts their mobility in daily *** a humanoid prosthetic hand would be an effective way of restoring lost hand *** a prosthetic hand design,replicating the natural and dexterous grasping functions with a few actuators remains a big *** this study,a function-oriented optimization design(FOD)method is proposed for the design of a tendon-driven humanoid prosthetic *** optimization function of different functional conditions of full-phalanx contact,total contact force,and force isotropy was constructed based on the kinetostatic model of a prosthetic finger for the evaluation of grasping *** a genetic algorithm,the optimal geometric parameters of the prosthetic finger could be determined for specific functional *** results reveal that the structure of the prosthetic finger is significantly different when designed for different functional requirements and grasping target sizes.A prosthetic finger was fabricated and tested with grasping *** mean absolute percentage error between the theoretical value and the experimental result is less than 10%,demonstrating that the kinetostatic model of the prosthetic finger is effective and makes the FOD method *** study suggests that the FOD method enables the systematic evaluation of grasping performance for prosthetic hands in the design stage,which could improve the design efficiency and help prosthetic hands meet the design requirements.

关键词： function-oriented tendon driven prosthetic hand optimization humanoid underactuated

Bromination of N-phenyloxypropyl-N'-ethyl-4,4'-bipyridium in cucurbit[8]uril molecular reactor

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Chinese Chemical Letters 2017年第2期28卷 463-466页

作者： tian-tian Li lan-lan Wen Hai-Long Ji Feng-Yu Liu Shi-Guo Sun State Key Laboratory of Fine Chemicals School of Chemistry Dalian University of Technology Key Laboratory of Xinjiang Endemic Phytomedicine Resources Ministry of Education School of Pharmacy Shihezi University

CB[n]（n= 6-8） is a family of synthetic macrocyclic host molecules composed of n glycoluril units,which can be employed as molecular reactor.N-Phenyloxypropyl-N＇-ethyl-4,4＇-bipyridium（1） was designed to form a host-guest inclusion complex with CB[n]（n = 6-8）,subsequently,the bromination reaction of 1 and its corresponding inclusion complexes was investigated in this *** the case of 1/CB[8],the folded including mode is quite helpful to acquire 1-bormination product completely through intramolecular charge transfer（ICT）,and CB[8]can provide a safe bromination environment for 1.

关键词： Cucurbituril Molecular reactor Intramolecular charge transfer(ICT) Bromination Inclusion

Hippocampal Segmentation in Brain MRI Images Using Machine Learning Methods: A Survey

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Chinese Journal of Electronics 2021年第5期30卷 793-814页

作者： PAN Yi LIU Jin tian Xu lan Wei GUO Rui Shenzhen Institute of Advanced Technology Chinese Academy of Sciences Hunan Provincial Key Lab on Bioinformatics School of Computer Science and EngineeringCentral South University School of Computer Electronics and Information Guangxi University

The hippocampus is closely related to many brain diseases, such as Alzheimer’s disease. Accurate measurement of the hippocampus is helpful for clinicians in identifying lesions and then diagnosing and treating the related brain diseases. Therefore, accurate segmentation of the hippocampus is of vital significance for the indepth study of many brain diseases. However, the accurate measurement of the hippocampus depends on its accurate segmentation, and hippocampal segmentation has always been a challenging problem due to the small size,irregular shape, and fuzzy boundaries with surrounding tissues of the hippocampus. With the development of machine learning, many innovative methods have been proposed to segment the hippocampus. The purpose of this survey is to provide a comprehensive overview of hippocampal segmentation in brain MRI images using machine learning methods. First, a brief introduction to hippocampal segmentation in brain MRI images is given. Then, common evaluation metrics of hippocampal segmentation are introduced. Next, brain hippocampal segmentation methods based on traditional machine learning and deep learning are described. Subsequently,some common open datasets and toolkits applied to brain hippocampal segmentation are presented. Finally,objective conclusions regarding hippocampal segmentation in brain MRI images using machine learning methods are drawn, and future developments and trends are identified for brain hippocampal segmentation.

关键词： biomedical MRI brain image segmentation machine learning methods brain hippocampal segmentation methods medical image processing neurophysiology related brain diseases diseases learning (artificial intelligence) hippocampus brain MRI images

Spray and mixing characteristics of liquid jet in a tubular gas-liquid atomization mixer

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Chinese Journal of Chemical Engineering 2021年第6期34卷 1-11页

作者： Lingzhen Kong Jiaqing Chen tian lan Huan Sun Kuisheng Wang School of Mechanical Engineering Beijing Institute of Petrochemical TechnologyBeijing 102617China Beijing Key Laboratory of Pipeline Critical Technology and Equipment for DeepWater Oil&Gas Development Beijing 102617China College of Mechanical and Electrical Engineering Beijing University of Chemical TechnologyBeijing 100029China

For the design and optimization of a tubular gas-liquid atomization mixer,the atomization and mixing characteristics of liquid jet breakup in the limited tube space is a key *** this study,the primary breakup process of liquid jet columnwas analyzed by high-speed camera,then the droplet size and velocity distribution of atomized droplets were measured by Phase-Doppler anemometry(PDA).The hydrodynamic characteristics of gas flow in tubular gas-liquid atomization mixer were analyzed by computational fluid dynamics(CFD)numerical *** results indicate that the liquid flow rate has little effect on the atomization droplet size and atomization pressure drop,and the gas flowrate is themain influence *** all experimental gas flowconditions,the liquid jet column undergoes a primary breakup process,forming larger liquid blocks and *** the gas flow rate(Qg)is less than 127 m^(3)·h^(−1),the secondary breakup of large liquid blocks and droplets does not occur in venturi throat *** Sauter mean diameter(SMD)of droplets measured at the outlet is more than 140μm,and the distribution is *** Qg>127 m^(3)·h^(−1),the large liquid blocks and droplets have secondary breakup process at the throat *** SMD of droplets measured at the outlet is less than 140μm,and the distribution is *** 127

关键词： Atomization mixing Liquid jet Primary breakup Droplet breakup Droplet size

Impacts of electrochemical disinfection on the viability and structure of the microbiome in secondary effluent water

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Frontiers of Environmental Science & Engineering 2024年第5期18卷 73-83页

作者： Marvin Yeung lan tian Yuhong Liu Hairong Wang Jinying Xi Environmental Simulation and Pollution Control State Key Joint Laboratory School of EnvironmentTsinghua UniversityBeijing100084China Graduate School at Shenzhen Tsinghua UniversityShenzhen518055China

Electrochemical disinfection(ECD)is a promising disinfection technique for wastewater reclamation;however,the impacts of ECD on the microbiome in secondary effluent wastewater remain *** this study,Propidium monoazide-qPCR(PMA-qPCR)and the plate count method were used to evaluate the inactivation performance,and the PMA-16S rRNA gene sequences of living cells were targeted to study the microbiome.A discrepancy was found between PMA-qPCR and the plate count method in the evaluation of cell count,with increases of 1.5 to 2.2 orders of magnitude in the disinfection rate after 150 s of ***,the cell count recovered and occasionally exceeded original levels within 3 d after *** was suppressed after ECD,but the microbiome after 150 s disinfection retained a higher level of evenness and stability in the community with a median Shannon index(>3.7).Pathogenic bacteria remained high in relative abundance even after 150 s of 25 V disinfection,but the biofilm-forming population was effectively suppressed by *** co-occurrence network revealed a centralized and fragile network as disinfection persisted,demonstrating the destabilizing effects of ECD on the *** pathways for cell membrane synthesis and organic compound degradation were enriched after *** reaction of the microbiome after ECD was similar to other disinfection techniques in terms of community structure.

关键词： Electrochemical disinfection Secondary effluent Microbiome

Secondary and activated X(γ)radiation of SPHIC particle therapy facility

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Nuclear Science and Techniques 2021年第4期32卷 84-91页

作者： Wei-Ming Sun Ning Du Wen-Dong tian lan Wang Department of Medical Management Shanghai Proton and Heavy Ion CenterShanghai Engineering Research Center of Proton and Heavy Ion Radiation TherapyShanghai 201315China Siemens Healthineers Ltd. Shanghai 201321China

We report the secondary X(γ)radiation from the accelerator in a normal operating state and activated X(γ)radiation from the accelerator devices when the accelerator stops operating in the cancer treatment facility of the Shanghai Proton and Heavy Ion Center(SPHIC).These radiation measurements show us the structural radiation distribution along the beam lines and devices inside the accelerator room when the beam is on and off and can support the radiation protection design of the accelerator facility used for cancer treatment and help evaluate the accumulated radiation dose in the case of an emergency,such as a personal safety system failure or a radiation *** radiation dose rate measured in this facility shows that the facility is safe from the radiation protection *** shooting the quality assurance(QA)beam,the radiation dose rate in the treatment room was also measured to investigate the radiation dose space distribution and decay time *** addition,the time period before safely entering the treatment room after determining the shooting of the QA beam is recommended to be approximately 5 min.

关键词： Secondary radiation Activated radiation Nuclear safety and radiation protection Dose rate Accelerator

Optimized Consensus for Blockchain in Internet of Things Networks via Reinforcement Learning

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Tsinghua Science and Technology 2023年第6期28卷 1009-1022页

作者： Yifei Zou Zongjing Jin Yanwei Zheng Dongxiao Yu tian lan Institute of Intelligent Computing School of Computer Science and TechnologyShandong UniversityQingdao 266237China Department of Electrical and Computer Engineering George Washington UniversityWashingtonDC 20052USA

Most blockchain systems currently adopt resource-consuming protocols to achieve consensus between miners;for example,the Proof-of-Work(PoW)and Practical Byzantine Fault Tolerant(PBFT)schemes,which have a high consumption of computing/communication resources and usually require reliable communications with bounded ***,these protocols may be unsuitable for Internet of Things(IoT)networks because the IoT devices are usually lightweight,battery-operated,and deployed in an unreliable wireless ***,this paper studies an efficient consensus protocol for blockchain in IoT networks via reinforcement ***,the consensus protocol in this work is designed on the basis of the Proof-of-Communication(PoC)scheme directly in a single-hop wireless network with unreliable communications.A distributed MultiAgent Reinforcement Learning(MARL)algorithm is proposed to improve the efficiency and fairness of consensus for miners in the blockchain *** this algorithm,each agent uses a matrix to depict the efficiency and fairness of the recent consensus and tunes its actions and rewards carefully in an actor-critic framework to seek effective *** results from the simulation show that the fairness of consensus in the proposed algorithm is guaranteed,and the efficiency nearly reaches a centralized optimal solution.

关键词： consensus in blockchain Proof-of-Communication(PoC) MultiAgent Reinforcement Learning(MARL) Internet of Things(IoT)networks

Core-shell Cu@SiO_(2)/SiO_(2) catalyst for 1,6-hexanediol dehydrogenation toε-caprolactone:High activity and stability from core-shell nanostructure

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Nano Research 2023年第10期16卷 12270-12280页

作者： Fengyang Jiang tian lan Jiaqiang Sun Guofeng Zhao Yong Lu Shanghai Key Laboratory of Green Chemistry and Chemical Processes School of Chemistry and Molecular EngineeringEast China Normal UniversityShanghai 200062China State Key Laboratory of Coal Conversion Institute of Coal ChemistryChinese Academy of SciencesTaiyuan 030001China Key Laboratory of Functional Molecular Solids Ministry of EducationCollege of Chemistry and Materials ScienceAnhui Normal UniversityWuhu 241002China College of Chemistry and Materials Science Anhui Normal UniversityWuhu 241002China

The gas-phase dehydrogenation of 1,6-hexanediol(1,6-HDO)toε-caprolactone(ε-CL)over the high-performance Cu-based catalysts is highly desirable,but with grand challenges,because the Cu nanoparticles(NPs)are easy to be sintered with the low Hüttig temperature(250℃ of reaction temperature).Herein,we report a highly efficient silica-encapsulated nano-Cu catalyst(Cu@SiO_(2)/SiO_(2))prepared via a complexation–impregnation method for the dehydrogenation of 1,6-HDO,exhibiting a 1,6-HDO conversion of 95.3%andε-CL selectivity of 80.0%at 270℃.The catalyst also has the outstanding thermal stability(without sintering up to 270℃ for 100 h on stream),which can be attributed to the effective encapsulation of the SiO_(2)*** addition,the reaction network of 1,6-HDO dehydrogenation is ***,the pyridine-diffuse reflectance infrared Fourier transform spectroscopy(DRIFTS)and in-situ X-ray photoelectron spectroscopy(XPS)reveal that the Cu^(0) species favor the conversion of 1,6-HDO toε-*** synergistic effect of Cu+and Cu^(0) benefits the conversion ofε-CL to 2-methylcyclopentanone(2-MCPN).This study is beneficial for designing the high-performance Cu-based catalysts for 1,6-HDO toε-CL,understanding the reaction network of 1,6-HDO dehydrogenation over the Cu-based catalysts,and offering a strong foundation for the largescale production ofε-CL.

关键词： core–shell nanostructure Cu-based catalyst 1 6-hexanediol dehydrogenation ε-caprolactone

Effects of graphite on the microstructure and properties of ultrafine WC-11Co composites by spark plasma sintering

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Rare Metals 2011年第1期30卷 63-67页

作者： SUN lan YANG tian＇en JIA Chengchang XIONG Ji School of Manufacturing Science and Engineering Sichuan University Chengdu 610065 China School of Materials Science and Engineering University of Science and Technology Beijing Beijing 100083 China

Ultrafine WC-11Co hard metals added with different proportions of graphite were prepared by spark plasma sintering at 40 MPa/1200°C for 5 min,and the influence of graphite as free carbon on the microstructure and mechanical properties were *** XRD analysis showed that decarbonization could be prevented by adding *** hard metals composed of finer and more homogeneous WC grains with little flaws can be achieved after 0 wt.% to 1.5 wt.% graphite was *** hardness and fracture toughness increase initially with increasing graphite content,and with over 1.5 wt.% they descend due to coarse grains and more ***,1.5 wt.% graphite is the optimal addition content in view of the hardness and transverse rupture ***,the coercive force decreases while the saturated magnetic intensity increases with the increase of graphite content.

关键词： composite materials tungsten carbide cobalt graphite spark plasma sintering microstructure mechanical properties