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Multimode Design and Analysis of an Integrated Leg-Arm Quadruped Robot with Deployable Characteristics

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Chinese Journal of Mechanical Engineering 2024年第3期37卷 41-61页

作者： Fuqun Zhao Yifan Wu Xinhua Yang Xilun Ding Kun xu sheng Guo Xiaodong Jin School of Mechanical Engineering and Automation Beihang UniversityBeijing 100191China School of Mechanical Electronic and Control EngineeringBeijing Jiaotong UniversityBeijing 100044China

To improve locomotion and operation integration, this paper presents an integrated leg-arm quadruped robot(ILQR) that has a reconfigurable joint. First, the reconfigurable joint is designed and assembled at the end of the legarm chain. When the robot performs a task, reconfigurable configuration and mode switching can be achieved using this joint. In contrast from traditional quadruped robots, this robot can stack in a designated area to optimize the occupied volume in a nonworking state. Kinematics modeling and dynamics modeling are established to evaluate the mechanical properties for multiple modes. All working modes of the robot are classified, which can be defined as deployable mode, locomotion mode and operation mode. Based on the stability margin and mechanical modeling, switching analysis and evaluation between each mode is carried out. Finally, the prototype experimental results verify the function realization and switching stability of multimode and provide a design method to integrate and perform multimode for quadruped robots with deployable characteristics.

关键词： Quadruped robot Multimode design Mode switching Locomotion Operation

High-temperature oxidation resistance of Si-coated C/SiC composites

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Rare Metals 2024年第9期43卷 4566-4572页

作者： Jie Xiao Hua-Yue Zhang sheng-Kai Gong Hui-Bin xu Hong-Bo Guo School of Materials Science and Engineering Beihang UniversityBeijing 100191China Key Laboratory of High-Temperature Structure Materials and Protective Coatings(Ministry of Industry and Information Technology) Beihang UniversityBeijing 100191China

In this paper,Si coatings were sprayed onto C/SiC composite substrates by atmospheric plasma spraying(APS).The high-temperature oxidation behavior of the substrate and coating at temperatures of 1100 and 1300℃was also *** C/SiC ceramic matrix composite will be damaged seriously and even failed due to the oxidation of carbon fibers in *** Si coating effectively improved the oxidation resistance of the C/SiC substrate in the high-temperature oxidation *** effect of the thickness of the Si coatings on the oxidation resistance was *** 150-μm coating is proved to enable the substrate to have the lowest oxidation weight loss and the best oxidation resistance after static oxidation for 5 h.

关键词： Ceramic matrix composites(CMCs) Carbon fiber Si coating Oxidation Plasma spray

Response characteristics of PWR primary circuit under SBLOCAs considering steam bypass discharging

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Nuclear Science and Techniques 2024年第6期35卷 189-201页

作者： Shuai Yang Xiang-Bin Li Yu-sheng Liu Jia-Ning xu De-Chen Zhang School of Nuclear Science and Engineering North China Electric Power UniversityBeijing 102206China Beijing Key Laboratory of Passive Safety Technology for Nuclear Energy Beijing 102206China Nuclear and Radiation Safety Center MEPBeijing 100084China

Small-break superposed station blackout(SBO)accidents are the basic design accidents of nuclear power *** the condition of a small break in the cold leg,SBO further increases the severity of the accident,and the steam bypass discharg-ing system(GCT)in the second circuit can play an important role in guaranteeing core *** explore the influence of the GCT on the thermal-hydraulic characteristics of the primary circuit,RELAP5 software was used to establish a numerical model based on a typical pressurized water reactor nuclear power *** different small breaks in the cold-leg super-posed SBO were selected,and the impact of the GCT operation on the transient response characteristics of the primary and secondary circuit systems was *** results show that the GCT plays an indispensable role in core heat removal during an accident;otherwise,core safety cannot be *** GCT was used in conjunction with the primary safety injection system during the placement *** the break diameter was greater than a certain critical value,the core cooling rate could not be guaranteed to be less than 100 K/h;however,the core remained in a safe state.

关键词： Steam bypass discharging Pressurized water reactor SBLOCA Numerical simulation

A new metal-organic rotaxane framework for enhanced ion conductivity of solid-state electrolyte in lithium-metal batteries

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Chinese Chemical Letters 2024年第9期35卷 481-485页

作者： Ying Li Yanjun xu Xingqi han Di han xuesong Wu Xinlong Wang Zhongmin Su School of Marine Science and Engineering Hainan Provincial Key Lab of Fine ChemistrySchool of Chemical Engineering and TechnologyHainan UniversityHaikou 570228China School of Chemistry and Environmental Engineering Changchun University of Science and TechnologyJilin Provincial Science and Technology Innovation Center of Optical Materials and ChemistryJilin Provincial International Joint Research Center of Photo-functional Materials and ChemistryChangchun 130022China State Key Laboratory of Supramolecular Structure and Materials Institute of Theoretical ChemistryCollege of ChemistryJilin UniversityChangchun 130021China

The composite polymer electrolyte has been obtained via incorporating LiCUST-701(a new metal–organic rotaxane framework modified by Li+)into poly(ethylene oxide)(PEO)matrix and give a high ionic conductivity of 4.02×10^(−4)S/cm at 60℃.DFT calculations were used to visualize the possible diffusion pathway of Li+.The all-solid-state cell assembled with LiFePO_(4),composite polymer electrolyte and lithium metal foil delivered with excellent cycling capability and stability even under high current densities.

关键词： Cucurbiturils Metal-organic rotaxane frameworks Ionic conduction Solid-state electrolyte Lithium-metal batteries

Icariin plus curcumol enhances autophagy through the mTOR pathway and promotes cathepsin B-mediated pyroptosis of prostate cancer cells

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Asian Pacific Journal of Tropical Biomedicine 2024年第2期14卷 55-64页

作者： xu-Yun Wang Wen-Jing xu Bo-Nan Li Tian-Song Sun Wen sheng Department of Andrology Beijing Hospital of Traditional Chinese MedicineCapital Medical UniversityBeijing100010China Department of Dermatology The First Affiliated Hospital of Hunan University of Chinese MedicineChangsha410021China School of Integrated Chinese and Western Medicine Hunan University of Chinese MedicineChangsha410208China Andrology Laboratory Hunan University of Chinese MedicineChangsha410208China School of Rehabilitation Medicine and Health Care Hunan University of MedicineHuaihua418000China School of Traditional Chinese Medicine Hunan University of MedicineHuaihua418000China

Objective:To examine the effect of icariin plus curcumol on prostate cancer cells PC3 and elucidate the underlying ***:We employed the Cell Counting Kit 8 assay and colony formation assay to assess cell viability and *** expression was analyzed using monodansylcadaverine *** and Western blot analyses were used to evaluate protein expressions related to autophagy,pyroptosis,and the mTOR *** damage was examined using the lactate dehydrogenase ***,cathepsin B and NLRP3 were detected by ***:Icariin plus curcumol led to a decrease in PC3 cell proliferation and an enhancement of *** levels of LC3-Ⅱ/LC3-Ⅰand beclin-1 were increased,while the levels of p62 and mTOR were decreased after treatment with icariin plus *** changes were reversed upon overexpression of ***,3-methyladenine resulted in a decrease in inflammatory cytokines,pyroptosis-related protein levels,and lactate dehydrogenase concentration,compared to the icariin plus curcumol *** cathepsin B reversed the regulatory effects of icariin plus ***:Icariin plus curcumol demonstrates great potential as a therapeutic agent for castration-resistant prostate cancer by enhancing autophagy via the mTOR pathway and promoting pyroptosis mediated by cathepsin *** findings provide valuable insights into the molecular mechanisms underlying the therapeutic potential of icariin and curcumol for prostate cancer treatment.

关键词： Icariin Curcumol Autophagy mTOR Cathepsin B Pyroptosis Prostate cancer

Energy saving analysis for CO_(2)–O_(2)mixed injection technology in converter steelmaking

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Journal of Iron and Steel Research International 2024年第5期31卷 1095-1103页

作者： Bao-chen han Chun-liang Gao Ya-qiang Li Dan Liu Guang-sheng Wei Rong Zhu Hebei Key Laboratory of Material Near-Net Forming Technology School of Material Science and EngineeringHebei University of Science and TechnologyShijiazhuang050018HebeiChina Department of Automotive Engineering Hebei Vocational University of Technology and EngineeringXingtai054000HebeiChina School of Metallurgical and Ecological Engineering University of Science and Technology BeijingBeijing100083China

Energy-saving in China's iron and steel industry still relies on the development and improvement of short-term energy saving ***,a special converter smelting technology incorporating energy saving was *** evaluate the energy-saving potential of the CO_(2)–O_(2)mixed injection(COMI)technology,collected production data were used to develop an improved techno-economic *** reveal that the technology can save energy through auxiliary material consumption,sensible heat of solid by-product,iron loss reduction,and energy *** application of COMI technology in an enterprise is cost effective,involving the energy saving potential of 0.206 GJ/t,the cost of conserved energy of−48.83 yuan/GJ,and a simple payback period of 0.35 year for a 60-million-yuan *** analysis shows that the investment cost and discount rate primarily influence the cost of conserved energy of the *** the discount rate increased,the cost of conserved energy also gradually ***,the COMI technology is an energy-saving technology with good development prospects.

关键词： Converter steelmaking COMI technology Energy saving Techno-economic model Investment cost

Multiple damage zones around hydraulic fractures generated by high-frequency pulsating hydraulic fracturing

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Petroleum Science 2024年第4期21卷 2688-2702页

作者： Yan Peng sheng-Jie Wei Guang-Qing Zhang Da-Wei Zhou Chuang-Chao xu School of Petroleum Engineering China University of Petroleum PetroChina Changqing Oilfield Company

Pulsating hydraulic fracturing(PHF) is a promising fracturing method and can generate a dynamic periodic pressure. The periodic pressure can induce fatigue failure of rocks and decrease initiation pressure of fracture. If the frequency of periodic pressure exceeds 10 Hz, the distribution of pressure along the main fracture will be heterogeneous, which is much different from the one induced by the common fracturing method. In this study, the impact of this special spatial feature of pressure on hydraulic fracture is mainly investigated. A coupled numerical simulation model is first proposed and verified through experimental and theoretical solutions. The mechanism of secondary fracture initiation around the main fracture is then discovered. In addition, sensitivity studies are conducted to find out the application potential of this new method. The results show that(1) this coupled numerical simulation model is accurate. Through comparison with experimental and theoretical data, the average error of this coupled model is less than 1.01%.(2) Even if a reservoir has no natural fracture, this heterogeneous distribution pressure can also cause many secondary fractures around the main fracture.(3) The mechanism of secondary fracture initiation is that this heterogeneous distribution pressure causes tensile stress at many locations along the main fracture.(4) Through adjusting the stimulation parameters, the stimulation efficiency can be improved. The average and amplitude of pressure can increase possibility of secondary fracture initiation. The frequency of this periodic pressure can increase number of secondary fractures. Even 6 secondary fractures along a 100 m-length main fracture can be generated.(5) The influence magnitudes of stimulation parameters are larger than ones of geomechanical properties, therefore, this new fracturing method has a wide application potential.

关键词： Tight reservoir Reservoir stimulation Numerical simulation Secondary fracture Fracture initiation

Sodium metals for single emitter strong coupling:Alternative plasmonic candidates beyond noble metals

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Science China(Physics,Mechanics & Astronomy) 2024年第8期67卷 106-117页

作者： Yi Zhang Shuying Chen Yuning han Xiulai xu Lin Zhou National Laboratory of Solid State Microstructures Collaborative Innovation Center of Advanced MicrostructuresJiangsu Key Laboratory of Artificial Functional MaterialsCollege of Engineering and Applied SciencesNanjing UniversityNanjing 210008China School of Information and Electronic Engineering(Sussex Artificial Intelligence Institute) Zhejiang Gongshang UniversityHangzhou 310018China Department of Physics&Astronomy University College LondonLondon WC1E 6BTUK State Key Laboratory for Mesoscopic Physics and Frontiers Science Center for Nano-optoelectronics School of PhysicsPeking UniversityBeijing 100871China

This work provides a theoretical investigation into the strong coupling between a single quantum emitter(QE)and the surface plasmons of sodium metals in two representative plasmonic systems,i.e.,the semi-infinite metal-dielectric interface and the metal nanoparticles(NPs)of monomer/dimer *** both configurations,sodium metals exhibit distinctly stronger coupling strength and lower optical loss in the optical region than their noble metal counterparts,demonstrating the ideal candidate characteristics for single-molecule-level strong couplings with distinctly facile operation *** results provide new insights into extreme light-matter interactions with potential applications in quantum information,optical sensors,quantum chemistry,etc.

关键词： sodium metals plasmonics single quantum emitter strong coupling pseudomode

Analytical prediction for time-dependent interaction of a circular tunnel excavated in strain-softening rock mass

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Rock Mechanics Bulletin

Rock Mechanics Bulletin 2024年第3期3卷 53-68页

作者： Chen xu sheng Wang Caichu Xia Institute of Rock Mechanics Ningbo UniversityNingbo315211ZhejiangChina Ningbo Key Laboratory of Energy Geostructure Ningbo315211ZhejiangChina

Viscoelastic plastic solutions for tunnel excavation in strain-softening rock mass and tunnel-rock interaction are proposed based on the Mohr-Coulomb and the Generalized Zhang-Zhu(GZZ)strength criterion considering stress *** solutions are verified by numerical simulations,results show that the theoretical solutions are close to the simulated *** evolutions of rock stresses,strains,displacements and support pressure were investigated and the influences of residual strength parameter,support stiffness,support timing,initial support pressure and viscosity coefficient on the rock deformation and the support pressure are discussed by proposed *** is found that strain-softening results in large deformation and high support pressure,with stiffer support and a larger viscosity coefficient contributing to even greater support *** support is recommended at the first stage to release the energy and reduce the support pressure by allowing a relatively large *** support pressure,especially the additional support pressure at the second stage will be much smaller if a higher initial support pressure is applied at the first *** can not only control the displacement rate of surrounding rock and improve the tunnel stability at the first stage by exerting sufficient support pressure immediately after tunnel excavation,but also greatly reduce the pressure acted on permanent support and improve the structure stability at the second ***,to avoid the instability of support structure,ductile support,which could not only deform continuously but also provide sufficient high support pressure,is recommended at the first stage.

关键词： Time-dependent behavior GZZ strength criterion Strain-softening Tunnel-rock interaction Stress path