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Structures and energetics of semicoherent interfaces of precipitates in hcp/bcc systems:A molecular dynamics study

Journal of Materials science & technology 2021年第8期67卷 50-60页

作者： Jin-Yu Zhang Fu-Zhi Dai Zhi-Peng Sun Wen-Zheng Zhang Key Laboratory of Advanced Materials(MOE) School of Materials Science and EngineeringTsinghua UniversityBeijing 100084China Science and Technology of Advanced Functional Composite Laboratory Aerospace Research Institute of Materials&Processing TechnologyBeijing 100076China Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of ChinaChengdu 610041China

α/β(hcp/bcc)interfaces are of great importance in the microstructure development and the mechanical properties of titanium and zirconium *** work contributes to the study of interface energetics and interfacial structures of the precipitate in the hcp/bcc system based on a simulation study using molecular statics(MS)and molecular dynamics(MD).The input orientation relationship(OR)was calculated based on the O-line *** on the energy of the interfaces containing the invariant line(IL),two preferred facets were determined by the Wulff construction,which explained the observed orientations of the habit plane(HP)and the side facet(SF).The deviation of the observed precipitate morphology from the equilibrium shape was discussed in terms of interface *** structures of the interfaces surrounding a three-dimensional(3 D)precipitate,including the preferred facets and the end face,were obtained at the atomic *** simulated dislocation structures and atomic structures in these interfaces are in good agreement with those of the experimental observations for Ti-Cr alloys.A method was suggested for modifying the O-cell structure with the guidance of the relaxed structure,yielding consistency between the calculated dislocation structure based on the generalized O-element approach and the simulation results.

关键词： Interface Misfit dislocation Precipitate

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Study on analysis method of loca dynamic response for steam generator heat transfer tube 29

Study on analysis method of loca dynamic response for steam ...

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2022 29th International Conference on Nuclear Engineering, ICONE 2022

作者： Lu, Xifeng Xiong, Furui Wang, Xinjun Ai, Honglei Li, Bingjin Shao, Xuejiao Yang, Kang Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of China Chengdu China Nuclear Power Institute of China Chengdu China

ISBN: (纸本)9780791886359

The equivalent effect relationship formula of LOCA hydraulic load in the bend section of the heat transfer tube of the steam generator is deduced. The hydraulic load factors affecting the stress of the heat transfer tube are derived. The spectrum analysis of the corresponding LOCA hydraulic load is carried out, and the spectral curve of the hydraulic load and the spectral characteristics of the hydraulic load are obtained. Modal analysis of steam generator heat transfer tubes is done. The modal analysis of the steam generator heat transfer tubes is performed. The spectral characteristics of the hydraulic load and the natural frequency information of different heat transfer tubes are compared. According to the comparison results, eight heat transfer tubes with the first-order natural frequency and the frequency corresponding to the peak value of the hydraulic load in the frequency domain curve were selected as the analysis objects, and the LOCA dynamic response analysis is carried out. The time-domain analysis of the LOCA hydraulic load of the steam generator heat transfer tube was performed, and the relationship between the hydraulic load and the bending radius of the heat transfer tube was obtained. The transient load of the steam generator heat transfer tube with different bending radii is calculated. By establishing the finite element models of the first, 31, 43, 57, 72, 83, 87, and 112 rows of heat transfer tubes, the time history analysis of the heat transfer tubes under the LOCA load is performed, and The stress distribution of the heat transfer tube under the LOCA load is obtained. The stress of the heat transfer tube calculated by this method is the maximum LOCA response. This method can screen out sensitive heat transfer tubes, avoiding the process of analyzing each heat transfer tube. This method can effectively improve the efficiency of LOCA analysis of heat transfer tubes and is a practical method. © 2022 American Society of Mechanical Engineers (ASME).

关键词： Frequency domain analysis

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Analysis of Factors Affecting Response Time of Magnetorheological Damper and Its Optimal design 2nd

Analysis of Factors Affecting Response Time of Magnetorheolo...

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2nd International Conference of Mechanical system Dynamics, ICMSD 2023

作者： Yan, Zhengwei Jiang, Min Zhu, Wei Institute of Launch Dynamics Nanjing University of Science and Technology Nanjing210094 China National Key Laboratory of Complex Multibody System Dynamics Nanjing210094 China

ISBN: (纸本)9789819980475

As a typical semi-active damping device, the response time of magnetorheological damper has a great influence on the working performance. In this paper, the factors affecting its magnetic field response were analyzed. Firstly, the effect of the dual-coil arrangement on the response time was analyzed, and the results showed that the response is faster when the current is reversed than when it is in the same direction;secondly, the magnetic parameters of different materials were tested with a soft magnetic DC meter, and the response times of different materials are derived;then, the effect of the structural parameters of the magnetic path on the response time was analyzed, and it was concluded that the response time grows with the rise of the channel gap and the yoke thickness, and the decrease of the pole length;Finally, the fastest response time and the largest adjustable multiplier are taken as the optimization objectives to obtain the Pareto set, which is then verified by the magnetic path simulation. The results showed that the reasonable design of coil, material and magnetic path structure parameters can effectively reduce the response time of the damper and significantly improve its performance. © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2024.

关键词： Deflection yokes

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Experimental Study of Turbulent Bubbly Flow in 180-Degree Elbow by PIV-PS Technique

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International Journal of Advanced Nuclear reactor design and technology 2022年第3期4卷 109-120页

作者： Chen, Wuguang Li, Songwei Mu, Xiaocheng Yang, Fan Yan, Zhigang Sun, Jiajin Huang, Guangyuan Cai, Kangbei Hu, Yuanbiao Yin, Junlian Wang, Dezhong School of Nuclear Science and Engineering Shanghai Jiao Tong University Shanghai200240 China Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of China Chengdu610041 China CGN Inspection Technology Co. Ltd. Jiangsu Suzhou215100 China

The curvature effect and bubbles are the key factors that affect the gas-liquid two-phase flow and turbulent characteristics in the 180-degree elbow. Limited by the difficulty of experimental measurement and numerical investigation, little is known about the two-phase flow evolution and turbulent modulation in 180-degree elbow. In this paper, a gas-liquid two-phase measurement technique, simultaneous Particle Image Velocimetry and Pulsed Shadowgraphy (PIV-PS) has been developed by combining two cameras through a spectroscope and optical filters and was applied to explore the two-phase characteristics in 180-degree elbow. In addition, an image post-processing method, based on bubble area detection and remaining particles estimation, was proposed. The characteristics of velocity and turbulent fields in the 180-degree elbow are experimentally studied in different conditions, and the evolution of the flow field in the elbow was also explored in detail. The results show that the horizontal velocity on the centerline of the elbow increases linearly with the liquid flow rates. However, with the introduction of bubbles, the linear feature is eliminated. The turbulent fields show that the introduction of bubbles suppresses turbulence at the low void fraction condition, and enhances at the high void fraction in bubble accumulation areas. © 2022 Xi'an Jiaotong University

关键词： Turbulence

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Reduced Multibody system Transfer Matrix Method for Ship system Vibration Modeling 2nd

Reduced Multibody System Transfer Matrix Method for Ship Sys...

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2nd International Conference of Mechanical system Dynamics, ICMSD 2023

作者： Rui, Xue He, Bin Wang, Xun Hao, Feiyu Chen, Yiheng Wang, Jinghong Cao, Hanchen Hou, Yibing Institute of Launch Dynamics Nanjing University of Science and Technology Nanjing210094 China National Key Laboratory of Complex Multibody System Dynamics Nanjing210094 China

ISBN: (纸本)9789819980475

The vibration performance of a ship such as maneuverability, comfort and reliability depends on the advanced dynamics design ability of ship system. A ship can be considered as a multi-rigid-flexible-body system composed of a large number of rigid bodies and flexible bodies. Its dynamics design ability is reliant on the advanced ship system dynamic theory. As a rather novel dynamics method for multibody systems, the Multibody system Transfer Matrix Method (MSTMM) has been developed in the past 30 years. Compared with ordinary dynamics methods, it has the advantages of low order of system matrix and independence of system degrees of freedom (DOF), fast computational speed and high programmability. It has been widely used to solve more than 150 engineering problems around the world. In particular, the Reduced Multibody system Transfer Matrix Method (RMSTMM) not only retains all the advantages of MSTMM, but also benefits from the high computational stability. In this paper, the multi-rigid-flexible-body system dynamics model of the ship system including a propeller subsystem, rotating shaft-hull subsystems, bearing seat subsystems, shaft-coupling subsystems and motor subsystem, and transfer equations as well as reduced transfer equations with recursive forms for the ship system and its elements, such as, rotating Timoshenko beam, rotating rigid cylinder, are developed for the first time by utilizing the RMSTMM. Consequently, the efficient modeling and simulation of the ship system dynamics and eigenfrequency are achieved. © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2024.

关键词： Transfer matrix method

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A Simplified Prediction Method of Magnetic Field Radiation of High-power Power Electronic Equipment 10th

A Simplified Prediction Method of Magnetic Field Radiation o...

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10th Frontier Academic Forum of Electrical Engineering, FAFEE 2022

作者： Zhang, Lei Jie, GuiSheng Gao, Shan Ji, ShengXian National Key Laboratory of Science and Technology on Vessel Integrated Power System Naval University of Engineering Hubei Wuhan430033 China

ISBN: (纸本)9789819934072

In the integrated power system (IPS) of ship platform, the conducted interference generated by high-power power electronic equipment will not only spread along the wire on the power grid, but also radiate to the surrounding space through the cable. With the increasingly strict electromagnetic compatibility standards, the magnetic field radiation generated by the high-power power electronic equipment has also been strictly limited. Predicting it can more effectively design the interference suppression measures and improve the electromagnetic compatibility (EMC) performance of equipment. First a basic cable radiation model is established based on the electromagnetic field theory. Then, the conducted interference estimation of power electronic equipment has been briefly introduced. Finally, a simplified prediction method of magnetic field radiation of high-power power electronic equipment according to the calculation results of conducted interference and cable radiation model is proposed. The effectiveness of this method is verified by experiments. © 2023, Beijing Paike Culture Commu. Co., Ltd.

关键词： Magnetic fields

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Dual-Polarized Wideband Wide-Beam Millimeter-Wave Magneto-Electric Dipole Antenna

Dual-Polarized Wideband Wide-Beam Millimeter-Wave Magneto-El...

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2023 Cross Strait Radio science and Wireless technology Conference, CSRSWTC 2023

作者： Gou, Linglong Ma, Jing Shi, Bin Zhu, Zhongbo Peng, Lin Guilin University of Electronic Technology Key Laboratory of Microwave and Optical Wave Application Technology Guangxi Guilin541004 China Beijing Simulation Center The Science and Technology on Special System Simulation Laboratory Beijing100854 China The National Key Laboratory of Science and Technology on Space Microwave Xi'an710100 China

ISBN: (纸本)9798350358971

In this manuscript, a dual-polarized wideband wide beamwidth magneto-electric (ME) dipole antenna for millimeter-wave mobile communication is proposed. As can be seen from the simulation results, this design exhibits excellent performance. Owing to the mutual resonances of the magnetic dipole and the electric dipole, large bandwidths of 64.8% and 59% (18.4 GHz-33 GHz and 17.29 GHz-33.9 GHz) are obtained for the two polarizations, respectively. The isolation between the two ports is greater than 25 dB. By loading metal vias, the antenna's beamwidth is widened to more than 100° through the whole operating band. The antenna size is 5mm×5 mm ×1.72 mm, and this compact structure is quite suitable for using in beam scanning antennas. © 2023 IEEE.

关键词： dual-polarization millimeter-wave (mm-wave) wideband

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DYNAMIC PRECISION EVALUATION OF COMPENSATED ION-CHAMBERS FOR reactor POWER MONITORING 29

DYNAMIC PRECISION EVALUATION OF COMPENSATED ION-CHAMBERS FOR...

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2022 29th International Conference on Nuclear Engineering, ICONE 2022

作者： Huang, Qichang Liu, Mingxing Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of China Chengdu China A College of Computer Sichuan University Chengdu China

ISBN: (纸本)9780791886373

During reactor power monitoring, compensated ion-chambers (CICs) are assembled by two similar gas-filled detectors. The gamma compensation of CICs is essential for detecting precision of thermal neutrons, and requires a pairs of fully matched voltages. Descriptions of detecting precision include current formation model, in which applied voltages and radiation strength act in the process of collecting charged particles. However, the model of CICs are seldom applied in design work to evaluate the monitoring precision. Here we show that imbalance degree of collecting charged particles leads to mismatch of saturation currents depending on difference of recombination and diffusion in each sub-chambers. We analyzed a coaxial type compensated ion-chamber (DL-126), and found that applied voltages and radiation strength have significant impact for ion recombination and electron diffusion. For increasing precision of CICs, this result suggests a dynamic way to evaluate the output deviation using radiation strength. Furthermore, we found the compensation factor of two sub-chambers is only related to the applied voltages and remain unchanged in various radiation. Our results demonstrate how collecting regulars of charged particles are likely to function in setting applied voltages, calculating the charge loss as well as quantifying the saturation currents. We anticipate our analysis to be a starting point for revising detection precision of compensated ion-chambers. For example, evaluating the neutron fluence in the reactor shutdown and restart process, including monitoring task after accident. Furthermore, dynamic precision evaluation of these detectors is a major target of prognostics and health management for Nuclear Instrument. Copyright © 2022 by ASME.

关键词： Ions

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Research on Fault Diagnosis Method Based on Structural Causal Model in Tennessee Eastman Process 7th

Research on Fault Diagnosis Method Based on Structural Causa...

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7th International Conference on Computing, Control and Industrial Engineering, CCIE 2023

作者： Pu, Haoyuan Liu, Jie Chen, Zhi Yang, Xiaohua Ren, Changan Xu, Zhuoran Jian, Yifan School of Computer Science University of South China Hengyang China Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of China Chengdu China Intelligent Equipment Software Evaluation Engineering Technology Research Center of Hunan Hengyang China CNNC Key Laboratory on High Trusted Computing Hengyang China School of Nuclear Science and Technology University of South China Hengyang China

ISBN: (纸本)9789819927296

In the practical application of fault diagnosis in large-scale chemical systems, due to the danger of faults, the machine learning diagnosis methods used in current research often face the problem of scarcity of fault samples. This makes it difficult for the model to be trained effectively, thus affecting the fault detection rate of the model. Therefore, for the fault diagnosis of chemical system with small sample data, this paper proposes a diagnostic method that uses structural causal model to further combine the diagnostic results of the two machine learning methods, thereby improving global diagnostic performance. With the help of powerful system description ability of structural causal model, we can establish a causal graph for diagnostic process of the chemical system, and accurately construct the corresponding structural equations for the various diagnostic results of the two machine learning methods to combine them, thus improve the fault detection rate. The global results make up for the shortcomings of single machine learning method in small sample chemical system fault diagnosis. The verification on the chemical system simulation platform Tennessee Eastman process shows that, compared with the diagnosis results of the selected Gaussian Naive Bayes method and the K-nearest neighbour method, the results obtained by our method are effectively improved in fault detection rate of each fault in TEP. © 2023, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.

关键词： Failure analysis

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Flow and thermal modeling of liquid metal in expanded microchannel heat sink

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Frontiers in Energy 2023年第6期17卷 796-810页

作者： Mingkuan ZHANG Xudong ZHANG Luna GUO Xuan LI Wei RAO Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control School of Mechanical EngineeringTianjin University of TechnologyTianjin 300384China National Demonstration Center for Experimental Mechanical and Electrical Engineering Education Tianjin University of TechnologyTianjin 300384China Key Laboratory for Thermal Science and Power Engineering of the Ministry of Education Department of Engineering MechanicsTsinghua UniversityBeijing 100084China School of Mechanical Engineering Tianjin University of CommerceTianjin 300134China Institute of Refrigeration and Cryogenics Shanghai Jiao Tong UniversityShanghai 200240China Beijing Key Laboratory of CryoBiomedical Engineering and Key Laboratory of Cryogenics Beijing 100190China

Liquid metal-based microchannel heat sinks (MCHSs) suffer from the low heat capacity of coolant, resulting in an excessive temperature rise of coolant and heat sink when dealing with high-power heat dissipation. In this paper, it was found that expanded space at the top of fins could distribute the heat inside microchannels, reducing the temperature rise of coolant and heat sink. The orthogonal experiments revealed that expanding the top space of channels yielded similar temperature reductions to changing the channel width. The flow and thermal modeling of expanded microchannel heat sink (E-MCHS) were analyzed by both using the 3-dimensional (3D) numerical simulation and the 1-dimensional (1D) thermal resistance model. The fin efficiency of E-MCHS was derived to improve the accuracy of the 1D thermal resistance model. The heat conduction of liquid metal in Z direction and the heat convection between the top surface of fins and the liquid metal could reduce the total thermal resistance (Rt). The above process was effective for microchannels with low channel aspect ratio, low mean velocity (Um) or long heat sink length. The maximum thermal resistance reduction in the example of this paper reached 36.0%. The expanded space endowed the heat sink with lower pressure, which might further reduce the pumping power (P). This rule was feasible both when fins were truncated (h_(2) < 0, h_(2) is the height of expanded channel for E-MCHS) and when over plate was raised (h_(2) > 0).

关键词： liquid metal cooling heat sink expanded microchannel flow and thermal modeling

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