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A product module mining method for PLM database

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Journal of Central South University 2016年第7期23卷 1754-1766页

作者：雷佻钰彭卫平雷金钟院华张秋华窦俊豪 School of power and mechanical Engineering Wuhan University

Modular technology can effectively support the rapid design of products, and it is one of the key technologies to realize mass customization design. With the application of product lifecycle management(PLM) system in enterprises, the product lifecycle data have been effectively managed. However, these data have not been fully utilized in module division, especially for complex machinery products. To solve this problem, a product module mining method for the PLM database is proposed to improve the effect of module division. Firstly, product data are extracted from the PLM database by data extraction algorithm. Then, data normalization and structure logical inspection are used to preprocess the extracted defective data. The preprocessed product data are analyzed and expressed in a matrix for module mining. Finally, the fuzzy c-means clustering(FCM) algorithm is used to generate product modules, which are stored in product module library after module marking and post-processing. The feasibility and effectiveness of the proposed method are verified by a case study of high pressure valve.

关键词： product design module division product module mining product lifecycle management (PLM) database

Axial coordination regulation of MOF-based single-atom Ni catalysts by halogen atoms for enhanced CO_(2) electroreduction

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Nano Research 2022年第12期15卷 10063-10069页

作者： Jia-Xin Peng Weijie Yang Zhenhe Jia Long Jiao Hai-Long Jiang department of Chemistry University of Science and Technology of ChinaHefei230026China department of power Engineering School of EnergyPower and Mechanical EngineeringNorth China Electric Power UniversityBaoding071003China

Single-atom catalysts(SACs),with the utmost atom utilization,have attracted extensive interests for various catalytic *** coordination environment of SACs has been recognized to play a vital role in catalysis while their precise regulation at atomic level remains an immense ***,a post metal halide modification(PMHM)strategy has been developed to construct Ni-N4 sites with axially coordinated halogen atoms,named Ni1-N-C(X)(X=CI,Br,and I),on pre-synthetic nitrogen-doped carbon derived from metal-organic *** axial halogen atoms with distinct electronegativity can break the symmetric charge distribution of planar Ni-N4 sites and regulate the electronic states of central Ni atoms in Ni1-N-C(X)(X=Cl,Br,and I).Significantly,the Ni1-N-C(CI)catalyst,decorated with the most electronegative Cl atoms,exhibits Faradaic efficiency of CO up to 94.7%in electrocatalytic CO_(2) reduction,outperforming Ni1-N-C(Br)and Ni1-N-C(I)***,Ni1-N-C(CI)also presents superb performance in Zn-CO_(2) battery with ultrahigh CO selectivity and great *** calculations reveal that the axially coordinated Cl atom remarkably facilitates*COOH intermediate formation on single-atom Ni sites,thereby boosting the CO_(2) reduction performance of Ni1-N-C(CI).This work offers a facile strategy to tailor the axial coordination environments of SACs at atomic level and manifests the crucial role of axial coordination microenvironments in catalysis.

关键词： metal-organic frameworks single-atom catalysts CO_(2)electroreduction axial coordination environment

Measurement and prediction of cavitating flow-induced vibrations

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Journal of Hydrodynamics 2018年第6期30卷 1064-1071页

作者： Qin Wu Chang-chang Wang Biao Huang Guo-yu Wang Shu-liang Cao School of mechanical Engineering Beijing Institute of Technology department of Energy and power Engineering Tsinghua University

The objective of this paper is to investigate the unsteady cavitation behaviors and the corresponding cavitating flow-induced vibrations. Results are presented for the modified NACA66 hydrofoils made of stainless steel and POM Polyacetate respectively at Re= 6.0×105for various cavitation regimes. The high-speed camera and the single point laser Doppler vibrometer(LDV) are used to observe the transient cavitating flow patterns and measure the vibration velocities. The results showed that the vibration amplitude increases dramatically for the cloud cavitation due to the development of large-scale cloud cavity. The main flow-induced frequencies, which are in accordance with the cavity shedding frequency, decrease with the decrease of the cavitation number. As for the effect of the hydroelastic response on the vibration behavior, the lift coefficient for the POM Polyacetate hydrofoil fluctuates more significantly with a larger mean value than that for the stainless steel hydrofoil. Compared with the vaporous cavity along the suction side of the stainless steel hydrofoil, the cavity for POM Polyacetate hydrofoil appears to be fragmentized. The main vibration frequencies for the POM Polyacetate hydrofoil are larger than that for the stainless steel hydrofoil, with the chaotic hydroelastic response with high frequency.

关键词： Cavitating flow flow-induced vibrations hydrofoil

Numerical Investigation on the Effects of Design Parameters and Operating Conditions on the Electrochemical Performance of Proton Exchange Membrane Water Electrolysis

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Journal of Thermal Science 2023年第6期32卷 1989-2007页

作者： HASSAN Alamir H. WANG Xueye LIAO Zhirong Xu Chao Key Laboratory of power Station Energy Transfer Conversion and System of MOE School of EnergyPower and Mechanical EngineeringNorth China Electric Power UniversityBeijing102206China mechanical power Engineering department Faculty of Engineering-MattariaHelwan UniversityCairo11718Egypt

Proton exchange membrane electrolysis cell(PEMEC)is one of the most promising methods to produce hydrogen at high purity and low power *** this study,a three-dimensional non-isothermal model is used to simulate the cell performance of a typical PEMEC based on computational fluid dynamics(CFD)with the finite element ***,the model is used to investigate the distributions of current density,species concentration,and temperature at the membrane/catalyst(MEM/CL)***,the effects of operating conditions and design parameters on the polarization curve,specific electrical energy demand,and electrical cell efficiency are *** results show that the maximum distribution of current density,hydrogen concentration,oxygen concentration,and temperature occur beneath the core ribs and increase towards the channel outlet,while the maximum water concentration distribution happens under the channel and decreases towards the channel exit *** increase in gas diffusion layer(GDL)thickness reduces the uneven distribution of the contour at the MEM/CL *** is also found that increasing the operating temperature from 323 K to 363 K reduces the cell voltage and specific energy *** hydrogen ion diffusion degrades with increasing the cathode pressure,which increases the specific energy demand and reduces the electrical cell ***,increasing the thickness of the GDL and membrane rises the specific energy demand and lowers the electrical efficiency,but increasing GDL porosity reduces the specific electrical energy demand and improves the electrical cell efficiency;thus using a thin membrane and GDL is recommended.

关键词： hydrogen production proton exchange membrane water electrolysis gas diffusion layer cell efficiency

Dynamical analysis and performance evaluation of a biped robot under multi-source random disturbances

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Acta Mechanica Sinica 2014年第6期30卷 983-994页

作者： Chun-Biao Gan Chang-Tao Ding Shi-Xi Yang The State Key Laboratory of Fluid power Transmission and Control Department of Mechanical EngineeringZhejiang University

During bipedal walking,it is critical to detect and adjust the robot postures by feedback control to maintain its normal state amidst multi-source random disturbances arising from some unavoidable uncertain *** radical basis function（RBF）neural network model of a five-link biped robot is established,and two certain disturbances and a randomly uncertain disturbance are then mixed with the optimal torques in the network model to study the performance of the biped robot by several evaluation indices and a specific Poincar′e *** contrast with the simulations,the response varies as desired under optimal inputting while the output is fluctuating in the situation of disturbance *** results from noise inputting also show that the dynamics of the robot is less sensitive to the disturbance of knee joint input of the swing leg than those of the other three joints,the response errors of the biped will be increasing with higher disturbance levels,and especially there are larger output fluctuations in the knee and hip joints of the swing leg.

关键词： Biped robot Multi-source random disturbances Sensitive parameters RBF neural network Taguchi method Performance evaluation

Automatic and Rapid Throughflow-Based Optimal Design Method for Multi-Stage Axial-Flow Compressors

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Journal of Thermal Science 2025年第1期 77-91页

作者： LEI Fan ZHANG Xiawen JU Yaping ZHANG Chuhua department of Fluid Machinery and Engineering School of Energy and Power EngineeringXi'an Jiaotong University Production and Environmental department China Huaneng Group.Co.Ltd. State Key Laboratory for Strength and Vibration of mechanical Structures Xi'an Jiaotong University

Throughflow design has the advantages of less time consumption and large optimization space,and thus is the corner stone of advanced design system of multi-stage axial-flow *** majority of relevant studies were limited to the throughflow inverse designs,and quite few works have been till now devoted to the throughflow optimal *** this work,an automatic and rapid throughflow-based optimal design method is proposed for axial-flow compressors in which a throughflow inverse design solver is embedded in optimal genetic algorithm to improve the design efficiency of axial-flow *** types of design parameters in the throughflow inverse design of axial-flow compressors,i.e.,swirl and shroud curve,are simultaneously used to optimize both the blade shape and flow *** proposed method is validated by the redesign optimization of the benchmark axial-flow compressor NASA Stage 35,and the CFD predictions show that the throughflow-based optimization leads to 1.18% efficiency benefit at design *** proposed method is then utilized to the two-dimensional throughflow optimal design of a large-scale 6.5-stage axial-flow industrial *** optimal design results are confirmed by CFD predictions,indicating that the proposed method can effectively improve the design adiabatic efficiency of the compressors by 1.09% within a few minutes on desk-top *** throughflow design implications are also obtained for advanced axial-flow industrial *** work could enhance the capability of throughflow design method and has engineering application value to explore the throughflow optimization space of multi-stage axial-flow compressors.

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Realization of energy-saving glass using photonic crystals

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Frontiers in Energy 2018年第1期12卷 178-184页

作者： Yen-Hsiang CHEN Li-Hung LIAO Yu-Bin CHEN department of mechanical Engineering Cheng Kung University Tainan701 Taiwan China department of power mechanical Engineering TsingHua UniversityHsinchu 300 Taiwan China

This work successfully developed an energy- saving glass with wavelength selectivity. The glass is composed of a SiO2 substrate and two layers of three- dimensional photonic crystals. Each crystal is composed of identical and transparent polystyrene spheres after their self-assembling. The glass then possesses dual photonic band gaps in the near-infrared region to suppress penetration of thermal radiation. Experimental results show that the energy-saving glass decreases temperature increment in a mini-house. Moreover, the temperature after thermal equilibrium is lower than that inside a counterpart using ordinary glass.

关键词： energy-saving glass photonic crystals poly-styrene spheres self-assembly

Experimental study on microstructural and corrosion behaviors of friction stir processed steel with CoCrFeCuTi HEA reinforcement and effect of annealing

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Science China Technological Sciences 2025年第1期 233-250页

作者： S.Aravind KRISHNA N.RADHIKA Alokesh PRAMANIK N.JEYAPRAKASH department of mechanical Engineering Amrita School of EngineeringAmrita Vishwa Vidyapeetham School of Civil and mechanical Engineering Curtin University School of mechanical and Electrical Engineering China University of Mining and Technology

The ability to perform against extreme corrosion environments in stainless steel depreciates under challenging conditions in industrial applications. This can be resolved by employing surface modification techniques to modify the surface with the required characteristics. The present study investigates the outcomes of friction stir processing of SS304 with CoCrFeCuTi high entropy alloy(HEA) as reinforcement and the property enhancements post-annealing. The synthesized CoCrFeCuTi HEA exhibited irregular fragments with 17 μm mean particle size and body centred cubic(BCC) phase. The microstructure of the processed surface revealed ultra-refined grains with a uniform distribution of HEA filler. The microstructures of the samples annealed at 400℃, 550℃, 700℃ and 850℃ for 2 h also showed significant grain growth and grain refinements. The processed sample with HEA reinforcement annealed at 700℃ exhibited enhanced microhardness and tensile strength by 63% and 0.88 times than that of the processed sample with HEA pre-annealing. The subsequent electrochemical corrosion test displayed better corrosion resistance for the HEA-processed and annealed sample. Hot corrosion tests at 900℃ showcased excellent resistance for the HEA processed and annealed samples by 14.92%, 12.75%, and 14.83% against the samples pre-annealed under three different salt mixtures, and the corroded surface was analyzed.

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Structures and Magnetic Properties of Europium-Transition Metal-Gallium Ternary Intermetallic Compounds with 1:3 Type

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Chinese Physics Letters 2015年第1期32卷 158-161页

作者：何强郭永权 School of Energy power and mechanical Engineering North China Electric Power University

The crystal structures and magnetic properties of novel Eu TrGa3-r （T=Pd, It, Rh） in termetallic compounds are investigated by using powder x-ray diffraction and magnetic measurements. EuTrGa3-r crystallizes in orthorhombic structure with space group of Cmcm and Z = 4. There are four kinds of nonequivalent 4c crystal positions in EuTrGaa-r unit cell, which are occupied by 4Eu, 4GaⅠ, 4（GaⅡ, T） and 4GaⅢ, respectively. EuTrGa3-r ex- hibits the complex magnetic states in low-temperature regime, with the three-, two- and one-antiferromagnetic transitions occurring for T=Ir, T=Rh and T=Pd, respectively. It might be due to the Kondo effect： a localized antiferromagnetic interaction of the isolated impurity spins with the surrounding conduction electrons at low-temperature regime.

关键词： Pd Ga Structures and Magnetic Properties of Europium-Transition Metal-Gallium Ternary Intermetallic Compounds with 1 Type Eu