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Reforming nanostructured CuAg alloy to improve ductility and electrical conductivity

MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING 2023年第1期872卷

作者： Zhang, J. K. Tian, Y. Z. Pang, X. Y. Wang, J. H. Wang, J. W. Northeastern Univ Sch Mat Sci & Engn Key Lab Anisotropy & Texture Mat Minist Educ Shenyang 110819 Peoples R China Northeastern Univ Res Ctr Met Wires Shenyang 110819 Peoples R China State Grid Urban & Rural Elect Power Design Res Be Beijing 100078 Peoples R China Zhejiang Univ Ctr Electron Microscopy Hangzhou 310027 Peoples R China Zhejiang Univ Sch Mat Sci & Engn State Key Lab Silicon Mat Hangzhou 310027 Peoples R China Zhejiang Univ Inst Wenzhou Wenzhou Key Lab Novel Optoelect & Nano Mat Wenzhou 325006 Peoples R China

Nanostructured metallic materials often lack sufficient work-hardening capability and suffer premature necking during tensile loading. In this study, intense rolling strain was applied to process nanocrystalline CuAg sheet, and aging treatment was designed to further tailor the microstructure and properties. Features of grains, Ag precipitates and short-range ordered (SRO) structure were characterized by transmission electron microscope (TEM). Superior tensile strength of 600 MPa, uniform elongation of 10% and electrical conductivity of 86.7% IACS were successfully achieved. Mechanisms for the balanced mechanical and electrical properties were analyzed.

关键词： Cu-Ag alloy Tensile elongation Electrical conductivity Nanostructure Strength

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Target Positioning Optimization Method in power System

Target Positioning Optimization Method in Power System

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作者： S Ba Z B Hou D W Wang G Y Shi W H Zhang X J Han C Y Dong J J Liu State Grid Key Laboratory of Power Industrial Chip Design and Analysis Technology Beijing Smart-Chip Microelectronics Technology Co. Ltd Beijing Smart-Chip Semiconductor Technology Co. Ltd

This thesis presents a method that a position measurement method for moving targets is proposed based on the positioning method based on the time difference of arrival(TDOA) which is based on the research on the positioning problem of station inspection operators and equipment in complex working conditions. The probability error method is introduced to optimize the traditional positioning method that realizes the target node positioning by optimizing the distance difference between the target node to be located in the network domain environment and different base stations, which can effectively improve the positioning accuracy of staff and equipment in the station. Through experiments in a complex power frequency electric field environment, the test results show that the results calculated by the optimization method are better than the existing traditional positioning methods, and can effectively improve the positioning accuracy under the condition of line-of-sight, and realize the substation space Mobile target positioning to ensure the safety of operators.

关键词： Target Positioning Optimization Method in power System

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A novel method for spatiotemporal temperature prediction in offices by using Raman-distributed fiber-optic sensor with the data fusion method

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JOURNAL OF BUILDING ENGINEERING 2023年 78卷

作者： Qu, Guanhua Zang, Xingyu Meng, Hongrong Zhang, Yuanyuan Ren, Lei Liu, Gang Chen, Qingwei Lau, Siu-Kit Tianjin Univ Sch Architecture Tianjin 300072 Peoples R China Tianjin Univ Tianjin Key Lab Architectural Phys Environm & Ecol Tianjin 300072 Peoples R China Natl Univ Singapore Coll Design & Engn Singapore 117566 Singapore Huaqiao Univ Sch Architecture Xiamen 361021 Peoples R China State Grid Shandong Elect Power Co Econ & Technol Res Inst Jinan 250021 Peoples R China

The uneven distribution of temperature fields and dynamic personnel disturbance in open-plan offices are key research issues for achieving high-precision prediction of temperature fields. Using Raman-distributed fiber-optic sensors, we developed a novel method for predicting working area temperature in open-plan offices. The novelty of this study is that the proposed temperature prediction method can incorporate thermal environment changes caused by dynamic internal disturbances, which not only improves the temperature prediction accuracy, but also enables low-cost, high-density temperature field prediction. The method aimed to achieve high spatial resolution and strong generalizations for the temperature field, considering uneven temperature distributions and random personnel disturbances. An environmental adaptability calibration method was developed, reducing the measurement error to 0.09 degrees C. Using Computational Fluid Dynamics (CFD) transient simulation, we established a human impact quantification dataset for open-plan offices. Combining distributed fiber-optic sensors, the YOLO personnel recognition algorithm, and the human impact quantification dataset, we achieved temperature field prediction of personnel activity areas with an error of approximately 0.1 degrees C. The method's performance was validated through field experiments conducted in an open-plan office in Tianjin. The proposed low-cost, high spatial resolution temperature field prediction method can significantly improve temperature data acquisition accuracy for intelligent operation and maintenance of office buildings. Furthermore, it can provide data support for pre-adjustment control of indoor thermal environments by air conditioning systems through early temperature prediction, enabling further exploration of energy-saving and carbon reduction potentials in office building operations.

关键词： Distributed fiber-optic sensor Random personnel disturbances Temperature field prediction Environmental adaptability calibration

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ABNORMAL DETECTION OF WIND TURBINE CONVERTER BASED ON CWGANGP-CSSVM

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FRACTALS-COMPLEX GEOMETRY PATTERNS AND SCALING IN NATURE AND SOCIETY 2023年第6期31卷 2340139-2340139页

作者： Tang, Mingzhu Tang, Jun Wu, Huawei Wang, Yang Hu, Yiyun Liu, Beiyuan Alassafi, Madini O. Alsaadi, Fawaz E. Ahmad, Adil M. Xiong, Fuqiang Changsha Univ Sci & Technol Coll Energy & Power Engn Changsha 410114 Peoples R China Hubei Univ Arts & Sci Hubei Key Lab Power Syst Design & Test Elect Vehic Xiangyang 441053 Peoples R China Shanghai Dianji Univ Sch Elect Engn Shanghai 201306 Peoples R China Zhejiang Univ Inst Ind Proc Control Coll Control Sci & Engn State Key Lab Ind Control Technol Hangzhou 310058 Peoples R China Univ Washington Dept Math 4710 20th Ave NE Seattle WA 98105 USA King AbdulAziz Univ Fac Comp & Informat Technol Dept Informat Technol Jeddah 21589 Saudi Arabia State Grid Hunan Extra High Voltage Substn Co Changsha 410029 Peoples R China State Grid Hunan Elect Power Co Ltd Substn Intelligent Operat & Inspect Lab Changsha 410029 Peoples R China

Abnormal detection of wind turbine converter (WT) is one of the key technologies to ensure long-term stable operation and safe power generation of WT. The number of normal samples in the SCADA data of WT converter operation is much larger than the number of abnormal samples. In order to solve the problem of low abnormal data and low recognition rate of WTs, we propose a sample enhancement method for WT abnormality detection based on an improved conditional Wasserstein generative adversarial network. Since the anomaly samples of WT converters are few and difficult to obtain, the CWGANGP oversampling method is constructed to increase the anomaly samples in the WT converter dataset. The method adds additional category labels to the inputs of the generative and discriminative models of the generative adversarial network, constrains the generative model to generate few types of anomalous samples, and enhances the generative model's ability to generate few types of anomalous samples, enabling data generation in a prescribed direction. The smooth continuous Wasserstein distance is used instead of JS divergence as a distance metric to measure the probability distribution of real and generated data in the conditional generative response network and reduce pattern collapse. The gradient constraint is added to the CWGANGP model to enhance the convergence of the WGAN model, so that the generative model can synthesize minority class anomalous samples more effectively and accurately under the condition of unbalanced sample data categories. The quality of anomalous sample generation is also improved. Finally, the anomaly detection is made on the actual operating variator dataset for the unbalanced dataset and the dataset after reaching Nash equilibrium. The experimental results show that the method used in this paper has lower MAR and FAR in WT converter anomaly detection compared with other oversampling data balance optimization methods such as SMOTE, RandomOverSampler, GAN, etc.

关键词： Converter Category Imbalance Abnormal Detection CWGANGP Model Cost-Sensitive Support Vector Machine

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Intercalated ion tuning of the cross-plane thermal transport properties of graphite

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AIP ADVANCES 2020年第9期10卷 1-7页

作者： Ju, Wenjing Zhu, Chongming Wei, Zhiyong NARI Grp Corp State Grid Elect Power Res Inst Nanjing 211106 Peoples R China Southeast Univ Jiangsu Key Lab Design & Mfg Micronano Biomed Ins Nanjing 211189 Peoples R China Southeast Univ Sch Mech Engn Nanjing 211189 Peoples R China

The effects of the intercalated ion concentration on the cross-plane thermal conductivity and the thermal boundary conductance in the graphite/lithiated graphite interface are investigated from molecular dynamics simulations. At low ion concentration, the cross-plane thermal conductivity of the lithiated graphite is lower than that of the pristine graphite. However, as the intercalated ion concentration increases, the cross-plane thermal conductivity increases rapidly, even exceeding that of the pristine graphite at high ion concentration. By analyzing the variations of the cross-plane elastic constants and phonon dispersion relation with the intercalated ion concentration, it is found that the intercalated ions significantly increase the phonon irradiation heat flux along the cross-plane direction. Our study further shows that the variation of the intercalated ion concentrations can also modulate the thermal boundary conductance in the graphite/lithiated graphite interface. The non-equilibrium molecular dynamics simulations show that the thermal boundary conductance between graphite and lithiated graphite decreases as the lithiation level increases, which would worsen the thermal performance of Li-ion batteries. A one-dimensional atomic chain model is proposed to elaborate on how the effective spring stiffness of material influences the interfacial transmission of phonons with different frequencies. This work provides a quantitative calculation of the cross-plane thermal conductivity and thermal boundary conductance in intercalated graphite samples and is also extremely important for the thermal management and structural design of lithium-ion batteries. (C) 2020 Author(s).

关键词： Graphite

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Significant enhancement of thermal boundary conductance in graphite/Al interface by ion intercalation

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INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER 2020年 157卷 119946-119946页

作者： Wei, Zhiyong Ju, Wenjing Bi, Kedong Yang, Juekuan Chen, Yunfei Southeast Univ Jiangsu Key Lab Design & Manufacture Micro Nano B Nanjing 211189 Peoples R China Southeast Univ Sch Mech Engn Nanjing 211189 Peoples R China State Grid Elect Power Res Inst NARI Grp Corp Nanjing 211106 Peoples R China

The electrochemical intercalation of metal ions into layered materials is an innovative approach to actively and reversely regulate the thermal transport properties of layered materials. In this work, the molecular dynamics (MD) simulation and lattice dynamics calculation are performed to investigate the thermal boundary conductance (TBC) between metal aluminum (Al) and intercalated graphite with various lithium-ion (Li-ion) concentrations. Both the thermal relaxation simulation and the non-equilibrium MD simulation show that the TBC in the intercalated graphene/Al interface is significantly high as compared to that in pristine graphite/Al interface, by a factor of 5.5. Besides, the TBC presents a slightly increasing trend with increasing Li-ion concentration. This is because increasing the Li-ion concentration increases the out-of-plane phonon group velocity of the intercalated graphite, leading to a sharp increase of phonon irradiation heat flux. By calculating the phonon interfacial transmission coefficient that includes the inelastic scattering effects, it is found that the transmission from the intercalated graphite to Al significantly decreases with increasing Li-ion concentration. The competition between the increased phonon irradiation heat flux and the decreased phonon interfacial transmission coefficient results in the slight increase of the TBC at high Li-ion concentration. This study provides important guidance to develop novel electrode materials and structures for thermal management in Li-ion batteries. (C) 2020 Elsevier Ltd. All rights reserved.

关键词： Intercalated graphite thermal boundary conductance phonon molecular dynamics

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The corrosion analysis and prevention of secondary cable joints used in outdoor terminal boxes of substation in humid environment 5

The corrosion analysis and prevention of secondary cable joi...

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5th International Conference on Renewable Energy and Environmental Protection (ICREEP)

作者： Hu, Yujing Hu, Wei Yang, Wen Wu, Junjie Chang, Yan Yin, Fucheng Xie, Yi State Grid Hunan Elect Power Co Ltd Res Inst Changsha 410007 Peoples R China State Grid Hunan Elect Power Corp Yueyang Power S Yueyang 414000 Peoples R China Xiangtan Univ Sch Mat Sci & Engn Key Lab Mat Design & Preparat Technol Hunan Prov Xiangtan 411105 Peoples R China

The reasons for corrosion cracking of secondary cable joints used in outdoor terminal boxes of a 220 kV substation in humid environment were investigated by scanning electron microscopy (SEM), X-ray diffractometer (XRD), infrared spectroscopy (IR) and ion dissolution test. According to the results of ion dissolution test, polyvinyl chlorid (PVC) insulated and sheathed cable material would precipitate chloride (Cl) ions under humid environment and at a certain temperature, which leads to accelerated corrosion cracking of the exposed copper core wires of secondary cable. In addition, the newly supplied PVC and cross-linked polyethylene (XLPE) materials without Cl precipitation under the same experimental conditions, indicating that PVC materials would precipitate Cl after reaching a service time threshold. Therefore, it is recommended that XLPE used for the insulation materials and accessories of secondary cable in outdoor terminal box of substation, as well as humidity in the terminal box should be controlled.

关键词： Ions

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Variance analysis based distinguisher for template attack

Variance analysis based distinguisher for template attack

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International Conference on Computational Intelligence and Security

作者： Song Cheng Hailong Zhang Xiaobo Hu Shunxian Gao Huizhi Liu State Grid Key Laboratory of Power Industrial Chip Design and Analysis Technology Beijing Smart-Chip Microelectronics Technology Co. Ltd. Beijing China Beijing Engineering Research Center of High-Reliability IC with Power Industrial Grade Beijing Smart-Chip Microelectronics Technology Co. Ltd. Beijing China State Key Laboratory of Information Security Institute of Information Engineering Chinese Academy of Sciences Beijing China

In practice, different styles of side channel attacks can utilize the leakages of a crypto device to recover the used secret key, which can pose a serious threat on the physical security of a crypto device. Among different styles of side channel attacks, template attack can be information theoretically the strongest attack style. However, numerical problems can seriously influence the key-recovery efficiency of template attack in practice, which can make template attack useless in practice. In light of this, the variance analysis based distinguisher is proposed for template attack. Compared with the classical template attack, variance analysis based template attack can reduce the computational complexity of template attack from $O(d^analysis)$ to $O(d)$ , where $d$ denotes the number of interesting points. Besides, numerical problems do not exist anymore. Therefore, a large number of interesting points can be chosen to enlarge the leakage exploitation and accordingly optimize the key-recovery efficiency of template attack. The key-recovery efficiency of variance analysis based template attack is evaluated in both simulated and real scenarios, and the evaluation results show that compared with the classical template attack, variance analysis based template attack can maintain a high key-recovery efficiency while significantly decrease the number of traces that should be used in the profiling phase of template attack.

关键词： Side-channel attacks Robustness Computational efficiency Security Covariance matrices Computational complexity Computational intelligence

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Investigation of charge trapping mechanism in MoS2 field effect transistor by incorporating Al into host La2O3 as gate dielectric

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NANOTECHNOLOGY 2021年第30期32卷 305201-305201页

作者： Yang, Kun Chen, Yanning Wang, Shulong Han, Tao Liu, Hongxia Xidian Univ Sch Microelect Key Lab Wide Band Gap Semicond Mat & Devices Educ Xian 710071 Peoples R China Beijing Smart Chip Microelect Technol Co Ltd State Grid Key Lab Power Ind Chip Design & Anal T Beijing Peoples R China

The charge trapping effect plays a key role in multi-bit memory devices and brain-like neuron devices. Herein, MoS2 field effect transistors are fabricated, incorporating Al into host La2O3 as the gate dielectric, which exhibit excellent electrical properties with an on-off ratio in the memory window of similar to 10(6) and a memory window ratio of similar to 40%. Furthermore, the charge trapping and de-trapping processes were systematically studied, and the time constants are obtained from time-domain characteristics. Making use of the charge trapping effect, the threshold voltage of the device can be continuously adjusted. The oxide layer trap density and the interface state trap density are extracted using the charge separation method. These theoretical studies provide a deeper understanding of ways to control the charge trapping process, benefitting the commercialization of two-dimensional electronic devices and the development of new charge trapping devices.

关键词： MoS2 field effect transistor charge trapped hysteresis trap density capture time constant

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A New Terminal and Electric Meter Legality Authentication Method

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Journal of Computers (Taiwan) 2021年第6期32卷 176-182页

作者： Fu, Qingqin Ang, Zhengquan Yi, Ling Xu, Pingjiang Liu, Jia Liang, Zhaoqing Fu, Lili Yang, Chaobin Fan, Gaolin ZhongGuanCun XinHaiZeYou Technology Co.Ltd Haidian district Beijing China Beijing aerospace flight control center Haidian district Beijing China Beijing Chip Microelectronics Technology Co. Ltd. Key Lab of Power Grid Design and Analysis State Grid Corporation of China Changping district Beijing China

This paper analyzes the shortcomings of the traditional terminal and meter legality authentication methods, and proposes a new terminal and meter legality authentication method. This method calculates the internal authentication command of the power generation meter through the terminal, saves the communication process between the primary station and the electric meter, fully exerts the intermediate role of the terminal, improves the authentication efficiency, and improves the execution rate of the task. At the same time, the terminal supports the authentication method of the meter dispersion factor. Whenever the authentication is performed, the terminal key calculates the key of the meter according to the meter dispersion factor, thereby ensuring that each meter key required by the power information collection system is different. © 2021 Computer Society of the Republic of China. All rights reserved.

关键词： Terminals (electric)

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