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工程与科学中的计算机建模(英文) 2024年第1期138卷 473-487页

作者： Zhiguang Liu Shilin Wang Jian Zhao Jianhong Hao Fei Yu School of Control and Mechanical engineering Tianjin Chengjian UniversityTianjin300384China Comprehensive Business Department CATARC(Tianjin)Automotive Engineering Research Institute Co.Ltd.300339China School of Mechanical engineering Hebei University of TechnologyTianjin300130China

A real-time adaptive roles allocation method based on reinforcement learning is proposed to improve humanrobot cooperation performance for a curtain wall installation *** method breaks the traditional idea that the robot is regarded as the follower or only adjusts the leader and the follower in *** this paper,a self-learning method is proposed which can dynamically adapt and continuously adjust the initiative weight of the robot according to the change of the ***,the physical human-robot cooperation model,including the role factor is ***,a reinforcement learningmodel that can adjust the role factor in real time is established,and a reward and actionmodel is *** role factor can be adjusted continuously according to the comprehensive performance of the human-robot interaction force and the robot’s Jerk during the repeated ***,the roles adjustment rule established above continuously improves the comprehensive *** of the dynamic roles allocation and the effect of the performance weighting coefficient on the result have been *** results show that the proposed method can realize the role adaptation and achieve the dual optimization goal of reducing the sum of the cooperator force and the robot’s Jerk.

关键词： Human-robot cooperation roles allocation reinforcement learning

Dynamic simulation insights into friction weakening effect on rapid long-runout landslides:A case study of the Yigong landslide in the Tibetan Plateau,China

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China Geology 2024年第2期7卷 222-236页

作者： Zi-zheng Guo Xin-yong Zhou Da Huang Shi-jie Zhai Bi-xia Tian Guang-ming Li School of Civil and transportation engineering Hebei University of TechnologyTianjin 300401China School of Geological engineering and Geomatics Chang’an UniversityXi’an 710054China tianjin Municipal engineering Design&research institute(TMEDI) Tianjin 300392China

This study proposed a novel friction law dependent on velocity,displacement and normal stress for kinematic analysis of runout process of rapid *** well-known Yigong landslide occurring in the Tibetan Plateau of China was employed as the case,and the derived dynamic friction formula was included into the numerical simulation based on Particle Flow *** showed that the friction decreased quickly from 0.64(the peak)to 0.1(the stead value)during the 5s-period after the sliding initiation,which explained the behavior of rapid movement of the *** monitored balls set at different sections of the mass showed similar variation characteritics regarding the velocity,namely evident increase at the initial phase of the movement,followed by a fluctuation phase and then a stopping *** peak velocity was more than 100 m/s and most particles had low velocities at 300s after the landslide *** spreading distance of the landslide was calculated at the two-dimension(profile)and three-dimension scale,*** with the simulation result without considering friction weakening effect,our results indicated a max distance of about 10 km from the initial unstable position,which fit better with the actual situation.

关键词： Rapid long-runout landslide PFC Friction weakening Three-dimension Numerical simulation Tibetan Plateau Hydrogeology engineering Geological hazards survey engineering

Evaluation and attribution of trends in compound dry-hot events for major river basins in China

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Science China Earth Sciences 2024年第1期67卷 79-91页

作者： Shaotang XIONG Tongtiegang ZHAO Chengchao GUO Yu TIAN Fang YANG Wenlong CHEN Xiaohong CHEN Key Laboratory of water Security Guarantee in Guangdong-Hong Kong-Marco Greater Bay Area of Ministry of water Resources&Sun Yatsen University/Southern Marine Science and engineering Guangdong Laboratory(Zhuhai) Guangzhou 510275China China institute of water Resource and Hydropower research Beijing 100038China Pearl River Hydraulic research institute Guangzhou 510611China

Concurrent compound dry and hot events(CDHEs)amplified more damange on the ecosystems and human society than individual *** climate change,compound dry and hot events become more frequent on a global *** paper proposes a mathematical method to quantitatively attribute changes of CDHEs to changes of precipitation,change in temperature and change in the dependence between precipitation and *** attribution is achieved by formulating the total differential equation of the return period of CDHEs among Meta-gaussian model.A case study of China is devised based on monthly precipitation and temperature data during the period from 1921 to 2020 for 80 major river *** is found that temperature is the main driving factor of increases in CDHEs for 49 major river basins in China,except for the upper and middle reaches of the Yangtze *** West China,precipitation changes drove the increase in CDHEs in 18 river basins(23%),particularly in parts of North Xinjiang,Qinghai and *** the other hand,dependence between precipitation and temperature dominated changes of CDHEs in 13 river basins(16%)of China with other factors,including parts of South China,East China and Northwestern ***,changes in both the mean and spread of precipitation and temperature can also contribute to changes in CDHEs.

关键词： Climate extreme Compound dry and hot extreme Precipitation Temperature Return period

Interface strengthening for thermal sprayed WC-10Co4Cr coating subjected to pulsed magnetic treatment

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Rare Metals 2024年第2期43卷 780-795页

作者： Cheng-Kai Qian Qu Liu Heng Wang Ke-Jian Li Zhi-Peng Cai Department of Mechanical engineering Tsinghua UniversityBeijing100084China tianjin research institute for Advanced Equipment Tsinghua UniversityTianjin300304China State Key Laboratory of Tribology in Advanced Equipment Tsinghua UniversityBeijing100084China

The reliability of the coated industry components demands ideal fatigue properties of the coating,and it is mainly determined by the performance of the *** this study,pulsed magnetic treatment(PMT)was applied to the thermal sprayed WC-10Co4Cr coating,and the fatigue lifetime of the coated bolt increased by 219.82%under an imitation of the operating mode *** tests further proved that both the adhesion and cohesion strength were improved after PMT,and they benefit from the interface strengthening *** formation of coherent WC/Co interfaces was characterized by in-situ transmission electron microscopy(TEM),and the molecular dynamic simulations indicate that the work of separation of these interfaces is much higher than the original disordered *** stress was relaxed and distributed more homogeneously after PMT,and it mainly contributes to the coating/substrate *** work provides a new post-treatment method focusing on the interfaces in the WC-based coating and gives insight into its mechanism so that it is hopeful to be applied to other kinds of coatings.

关键词： Cemented carbide coating Pulsed magnetic treatment Interface strengthening Fatigue properties Adhesion strength

Mechanism and application of mechanical property improvements in engineering materials by pulsed magnetic treatment:A review

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Friction 2024年第10期12卷 2139-2166页

作者： Zhipeng CAI Chengkai QIAN Xu ZHANG Ning DAI Yao WU Wen JI State Key Laboratory of Tribology in Advanced Equipment Tsinghua UniversityBeijing 100084China Department of Mechanical engineering Tsinghua UniversityBeijing 100084China tianjin research institute for Advanced Equipment Tsinghua UniversityTianjin 300304China

Pulsed magnetic treatment(PMT)has been adopted as an effective strengthening method for engineering materials and components in recent years,and the development of its application depends on the comprehensive understanding of the nature of *** deep mechanism was thought initially to be the magnetostrictive effect,while further investigation found that the magnetic field could lead to the change of the defect states in the crystal,which is called the magnetoplastic *** to the complexity of the engineering materials,manifestations of the magnetoplastic effect become more diverse,and they were reviewed in the form of microstructure homogenization and interfacial ***,the mechanism of the magnetoplastic effect was discussed,focusing on the changes in the spin states under the external magnetic *** modifications could also alter material performances,especially the residual stress,plasticity,and fatigue ***,PMT with specific parameters can be utilized to obtain an ideal combination of microstructure,residual stress,and mechanical properties for better service performance of different mechanical parts,and its applications on machining tools and bearings are perfect *** work reviews the effect of PMT on the microstructure and properties of different materials and the mechanism,and it also summarizes the fundamental applications of PMT on essential mechanical parts.

关键词： pulsed magnetic treatment wear resistance microstructure modifications mechanical properties magnetoplastic effect

A single micro-LED manipulation system based on micro-gripper

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Nanotechnology and Precision engineering 2024年第2期7卷 45-52页

作者： Jie Bai Pingjuan Niu Erdan Gu Jianming Li Clarence Augustine TH Tee School of Mechanical engineering Tiangong University School of Electronic and Information engineering Tiangong University institute of Photonics University of Strathclyde tianjin Key Laboratory of Micro Low Gravity Environment Simulation Technology Tianjin Aerospace Electromechanical Equipment Research Institute Department of Electrical and Information engineering School of Physics and Electrical Information EngineeringZhejiang Normal University

Micro-LEDs(μLEDs) have advantages in terms of brightness, power consumption, and response speed. In addition, they can also be used as micro-sensors implanted in the body via flexible electronic skin. One of the key techniques involved in the fabrication of μLED-based devices is transfer printing. Although numerous methods have been proposed for transfer printing, improving the yield of μLED arrays is still a formidable task. In this paper, we propose a novel method for improving the yield of μLED arrays transferred by the stamping method, using an innovative design of piezoelectrically driven asymmetric micro-gripper. Traditional grippers are too large to manipulate μLEDs, and therefore two micro-sized cantilevers are added at the gripper tips. A μLED manipulation system is constructed based on the micro-gripper together with a three-dimensional positioning system. Experimental results using this system show that it can be used successfully to manipulate μLED arrays.

关键词： Micro-gripper Micro-LED Transfer printing Manipulation

Electrocatalytic NAD(P)H regeneration for biosynthesis

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Green Chemical engineering 2024年第1期5卷 1-15页

作者： Yaoxuan Li Guanhua Liu Weixi Kong Suoqing Zhang Yuemei Bao Hao Zhao Lihui Wang Liya Zhou Yanjun Jiang National-Local Joint engineering Laboratory for Energy Conservation in Chemical Process Integration and Resources Utilization School of Chemical Engineering and TechnologyHebei University of TechnologyTianjin300401China North China Pharmaceutical Group Corp Shijiazhuang050015China tianjin Food research institute Tianjin301609China

The highly efficient chemoselectivity,stereoselectivity,and regioselectivity render enzyme catalysis an ideal pathway for the synthesis of various chemicals in broad *** the cofactor of an enzyme is necessary but expensive,the conversed state of the cofactor is not beneficial for the positive direction of the *** regeneration using electrochemical methods has the advantages of simple operation,low cost,easy process monitoring,and easy product separation,and the electrical energy is green and ***,bioelectrocatalysis has great potential in synthesis by combining electrochemical cofactor regeneration with enzymatic *** this review,we detail the mechanism of cofactor regeneration and categorize the common electron mediators and enzymes used in cofactor *** reaction type and the recent progress are summarized in electrochemically coupled enzymatic *** main challenges of such electroenzymatic catalysis are pointed out and future developments in this field are foreseen.

关键词： Biosynthesis Cofactor regeneration Bioelectrocatalysis NAD(P)H Electron mediator

Energy-saving design and optimization of pressure-swing-assisted ternary heterogenous azeotropic distillations

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Chinese Journal of Chemical engineering 2024年第4期68卷 1-7页

作者： Lianjie Wu Kun Lu Qirui Li Lianghua Xu Yiqing Luo Xigang Yuan tianjin Key Laboratory of Organic Solar Cells and Photochemical Conversion College of Chemical and Chemical EngineeringTianjin University of TechnologyTianjin 300384China State Key Laboratory of Chemical engineering Tianjin UniversityTianjin 300072China

A huge amount of energy is always consumed to separate the ternary azeotropic mixtures by *** heterogeneous azeotropic distillation and the pressure-swing distillation are two kinds of effective technologies to separate heterogeneous azeotropes without entrainer *** give better play to the synergistic energy-saving effect of these two processes,a novel pressure-swing-assisted ternary heterogeneous azeotropic distillation(THAD)process is proposed *** this process,the ternary heterogeneous azeotrope is decanted into two liquid phases before being refluxed into the azeotropic distillation column to avoid the aqueous phase remixing,and three columns'pressures are modified to decrease the flowrates of the recycle *** the dividing wall column and heat integration technologies are introduced to further reduce its energy consumption,and the pressureswing-assisted ternary heterogeneous azeotropic dividing-wall column and its heat integration structure are achieved.A genetic algorithm procedure is used to optimize the proposed *** design results show that the proposed processes have higher energy efficiencies and lower CO_(2)emissions than the published THAD process.

关键词： Distillation Separation Process control Process systems

Donor-acceptor covalent organic frameworks-confined ultrafine bimetallic Pt-based nanoclusters for enhanced photocatalytic H_(2)generation

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Nano research 2024年第7期17卷 5835-5844页

作者： Yu Liu Yawen Shi Hua Wang Shengbo Zhang Collaborative Innovation Center of Chemical Science and engineering(tianjin) Key Laboratory for Green Chemical Technology of the Ministry of EducationSchool of Chemical Engineering and TechnologyTianjin UniversityTianjin 300350China School of Environmental Science and engineering Tianjin Key Laboratory of Biomass/Wastes UtilizationTianjin UniversityTianjin 300350China

Photocatalytic hydrogen generation from hydrogen storage media is an effective and promising approach for the green hydrogen industry as well as for achieving carbon neutrality ***,the lower photocatalytic efficiency due to the limited light trapping capacity,low electron transfer rate,and severe aggregation of nanoparticles caused by high surface energy seriously restricts their practical ***,we constructed a series of donor–acceptor(D–A)type covalent organic frameworks to confine ultrafine bimetallic Pt-based nanoclusters for photocatalytic hydrogen generation from ammonia borane(AB)*** visible light irradiation at 20℃,PtCo_(2)@covalent organic framework(COF)showed the highest photocatalytic activity with a turnover frequency(TOF)of 486 min−*** and density functional theory(DFT)calculations reveal that the high catalytic activity is mainly attributed to the strong electronic interactions between D–A type COF and ultrafine PtCo_(2)***,the D–A type COF can significantly enhance the light-trapping ability by fine-tuning the electron-acceptor type in the framework,and accelerate the photogenerated electron transfer from D–A type COF to PtCo_(2)nanocluster,which promotes the adsorption and activation of H_(2)O and AB molecules and accelerates hydrogen ***,PtCo_(2)@COF also exhibited ultra-high durability due to the significantly enhanced resistance to nanocluster aggregation caused by the nanopore confinement effect of D–A type *** believe that this work will provide a theoretical guide for the rational design of efficient D–A COFbased catalysts for photocatalysis.

关键词： light trapping electron transfer donor-acceptor covalent organic frameworks(D-A COFs) bimetallic nanoclusters photocatalysis

Hepatomegaly and jaundice as the presenting symptoms of systemic light-chain amyloidosis: A case report

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World Journal of Gastrointestinal Oncology 2024年第2期16卷 550-556页

作者： Xu Zhang Fei Tang Yan-Ying Gao De-Zhao Song Jing Liang Department of Gastroenterology and Hepatology The Third Central Hospital of TianjinTianjin 300170China tianjin Key Laboratory of Extracorporeal Life Support for Critical Diseases Artificial Cell Engineering Technology Research CenterTianjin Institute of Hepatobiliary DiseaseTianjin 300170China Department of Interventional Radiology The Third Central Hospital of TianjinTianjin 300170China

BACKGROUND Light chain(AL)amyloidosis is a plasma cell dyscrasia characterized by the pathologic production and extracellular tissue deposition of fibrillar proteins derived from immunoglobulin AL fragments secreted by a clone of plasma cells,which leads to progressive dysfunction of the affected *** two most commonly affected organs are the heart and kidneys,and liver is rarely the dominant affected organ with only 3.9%of cases,making them prone to misdia-gnosis and missed *** SUMMARY A 65-year-old woman was admitted with a 3-mo history of progressive jaundice and marked ***,based on enhanced computed tomography scan and angiography,Budd-Chiari syndrome was considered and balloon dilatation of significant hepatic vein stenoses was ***,addi-tional diagnostic procedures,including liver biopsy and bone marrow-exami-nation,revealed immunoglobulin kapa AL amyloidosis with extensive liver involvement and hepatic vascular *** disease course was progre-ssive and fatal,and the patient eventually died 5 mo after initial presentation of *** AL amyloidosis with isolated liver involvement is very rare,and can be easily misdiagnosed as a vascular disease.

关键词： Jaundice Hepatomegaly Liver amyloidosis Kappa light chain Pseudo-Budd-Chiari syndrome Case report