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2024 Photonics and Electromagnetics Research Symposium, PIERS 2024

作者： Li, Yuxin Zhou, Wenying Xu, Jinjing Lanzhou Jiaotong University Key Lab of Opt-Electronic Technology and Intelligent Control of Ministry of Education Gansu Lanzhou730070 China

ISBN: (纸本)9798350375909

The MIMO antenna for mobile communication terminals is proposed for improving its communication ability in different networks. It can avoid the problem of signal attenuation and poor signal quality caused by antenna band mismatch. The dimension of the overall antenna size is 58mm×120mm (0.68λ0×1.41λ0, where λ0 is the wavelength of 3.5GHz). The MIMO antenna can cover the following areas: GSM 1800, UMTS, LTE, and 5G band N78. The proposed antenna consists of two types of radiating units, including an E-type radiating unit and an L-type radiating unit. The E-type radiating unit contains two frequency bands of 1.71 ∼ 1.75GHz and 3.36 ∼ 3.61GHz respectively, which is worked for GSM1800 and 5G band N78. The L-type radiating unit covers 2.58 ∼ 2.69GHz, after moving the L-type patch, it can cover 2.05 ∼ 2.17GHz, which works for UMTS and 5G band LTE. The E-type patch antenna is center symmetric loaded to improve the gain of the proposed MIMO antenna. The simulation results show that the antenna's efficiency is higher than 80% in 2.1GHz, 2.6GHz, and 3.5GHz bands with ECC (Envelope Correlation Coefficient) less than 0.16. A prototype of the proposed 6-antenna array is manufactured and measured. The measurement results show a return loss of 8.72dB and an isolation of 14.83dB, basically consistent with simulation results. It is also worth noticing that the proposed antenna could operate in the highly anticipated next-generation Wi-Fi 6E. © 2024 IEEE.

关键词： Slot antennas

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The configuration of Au^(δ+)-ZrO_(2)^(δ−)species induced activation enhances electrocatalytic CO_(2)to formate conversion

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Nano Research 2024年第7期17卷 6006-6015页

作者： Yongjian Jia Yadi Zhang Mengque Lin Yangyang Cheng Yanjie Xu National Engineering Research Center for Technology and Equipment of Environmental Deposition Lanzhou Jiaotong UniversityLanzhou 730070China Key Lab of Opt-Electronic Technology and Intelligent Control of Ministry of Education Lanzhou Jiaotong UniversityLanzhou 730070China School of Environmental Engineering and Chemistry Luoyang Institute of Science and TechnologyLuoyang 471023China

Electrochemical CO_(2)conversion into value-added chemicals is a promising technology to solve the greenhouse effect and recycle chemical ***,the electrochemical CO_(2)reduction reaction(e-CO_(2)RR)is seriously compromised by weak CO_(2)adsorption and a rough CO_(2)activation process based on the chemical inertness of the CO_(2)molecule and the formed fragile metal–C/O *** this paper,we designed and fabricated Au particles embedded in ZrO_(2).The configuration of Au particles being of positive charge and ZrO_(2)with negative charge is induced and generated by metal–support interactions(MSIs).As a result,Au/ZrO_(2)@C presents a big difference in the CO_(2)conversion compared with the known work,affording a formate yield of 112.5μmol·cm^(−2)·h^(−1)at−1.1 V *** hydrogen electrode(RHE),and a max formate Faradaic efficiency of up to 94.1%at−0.9 V *** superior performance was attributed to the activated Au–ZrO_(2)interface to form the Au^(δ+)*** insitu Fourier transform infrared(FTIR)spectroscopy and theoretical calculations show that the MSIs configuration can be inclined to the*OCO intermediate generation on Au^(δ+)species activating CO_(2)molecules and then accelerate the formation of the*OCHO intermediate in e-CO_(2)RR,thereby favoring the CO_(2)conversion to formate.

关键词： electrochemical CO_(2)reduction reaction(e-CO_(2)RR) Au_(δ+)species formic acid OCHO intermediate metal-support interactions

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Multi-objective operation optimization study of high-speed train ATO based on improved particle swarm algorithm

Multi-objective operation optimization study of high-speed t...

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2023 International Conference on Automation control, Algorithm, and intelligent Bionics, ACAIB 2023

作者： Wang, Ning Li, Peng Shi, Jianqiang Wei, Zongshou Key Laboratory of Plateau Traffic Information Engineering and Control of Gansu Province Lanzhou Jiaotong University Lanzhou730070 China CommuKey Lab of Opt-Electronic Technology and Intelligent Control of Ministry of Education Lanzhou730070 China

ISBN: (纸本)9781510667662

A speed profile optimization method based on improved particle swarm algorithm (IPSO) is proposed to address the problems of on-time performance, comfort and energy consumption in the process of automatic train operation (ATO) of high-speed trains. Since the traditional particle swarm algorithm (PSO) has many shortcomings, this paper adopts the nonlinear inertia weight decrement of cosine instead of the linear inertia weight decrement of the traditional particle swarm algorithm, as well as the adaptive adjustment strategy for the acceleration factor, which expands the global search range and avoids the local optimum, while accelerates the convergence speed. Taking the safety of train operation and the train dynamics model as constraints, a multi-objective operation optimization model for high-speed trains is established. The multi-objective operation optimization model of high-speed trains is solved by combining the improved particle swarm algorithm with the maneuvering conditions. Finally, the effectiveness of the improved particle swarm algorithm is verified through the simulation of the selected lines, which makes each performance index relatively optimal. © 2023 SPIE.

关键词： Energy utilization

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Recognition of Hybrid PQ Disturbances Based on Multi-Resolution S-Transform and Decision Tree

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Energy Engineering 2023年第5期120卷 1133-1148页

作者： Feng Zhao Di Liao Xiaoqiang Chen Ying Wang School of Automation and Electrical Engineering Lanzhou Jiaotong UniversityLanzhou730070China Key Lab of Opt-Electronic Technology and Intelligent Control of Ministry of Education Lanzhou Jiaotong UniversityLanzhou730070China

Aiming at the problems of multiple types of power quality composite disturbances,strong feature correlation and high recognition error rate,a method of power quality composite disturbances identification based on multiresolution S-transform and decision tree was ***,according to IEEE standard,the signal models of seven single power quality disturbances and 17 combined power quality disturbances are given,and the disturbance waveform samples are generated in ***,in order to improve the recognition accuracy,the adjustment factor is introduced to obtain the controllable time-frequency resolution through multi-resolution S-transform time-frequency domain *** this basis,five disturbance time-frequency domain features are extracted,which quantitatively reflect the characteristics of the analyzed power quality disturbance signal,which is less than the traditional method based on ***,three classifiers such as K-nearest neighbor,support vector machine and decision tree algorithm are used to effectively complete the identification of power quality composite *** results showthat the classification accuracy of decision tree algorithmis higher than that of K-nearest neighbor and support vector ***,the proposed method is compared with other commonly used recognition *** results show that the proposedmethod is effective in terms of detection accuracy,especially for combined PQ interference.

关键词： Hybrid power quality disturbances disturbances recognition multi-resolution S-transform decision tree

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Bearing Fault Diagnosis with DDCNN Based on intelligent Feature Fusion Strategy in Strong Noise

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Computers, Materials & Continua 2023年第12期77卷 3423-3442页

作者： Chaoqian He Runfang Hao Kun Yang Zhongyun Yuan Shengbo Sang Xiaorui Wang College of Electronic Information and Optical Engineering Taiyuan University of TechnologyTaiyuan030024China Key Lab of Advanced Transducers and Intelligent Control System of the Ministry of Education Taiyuan030024China

intelligent fault diagnosis in modern mechanical equipment maintenance is increasingly adopting deep learning ***,conventional bearing fault diagnosis models often suffer from low accuracy and unstable performance in noisy environments due to their reliance on a single input ***,this paper proposes a dual-channel convolutional neural network(DDCNN)model that leverages dual data *** DDCNN model introduces two key ***,one of the channels substitutes its convolution with a larger kernel,simplifying the structure while addressing the lack of global information and shallow ***,the feature layer combines data from different sensors based on their primary and secondary importance,extracting details through small kernel convolution for primary data and obtaining global information through large kernel convolution for secondary *** experiments conducted on two-bearing fault datasets demonstrate the superiority of the two-channel convolution model,exhibiting high accuracy and robustness even in strong noise ***,it achieved an impressive 98.84%accuracy at a Signal to Noise Ratio(SNR)of−4 dB,outperforming other advanced convolutional models.

关键词： Fault diagnosis dual-data dual-channel feature fusion noise-resistance

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Radiation Effect Analysis on Human Head Caused by Different Frequencies of Mobile Phone Antenna

Radiation Effect Analysis on Human Head Caused by Different ...

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2022 International Applied Computational Electromagnetics Society Symposium, ACES-China 2022

作者： Zhang, Xi-Yu Zhou, Wen-Ying Lanzhou Jiaotong University Key Lab of Opt-Electronic Technology and Intelligent Control of Ministry of Education Gansu Lanzhou China

ISBN: (纸本)9781665452366

This article discusses the bio-electromagnetic effects of the human head who exposure to the different operation frequency of three kinds of mobile phones. Three kinds of exposure sources with microwave and millimeter-wave bands respectively, which include the dual-band PIFA antenna operating at 900 MHz and 1860 MHz, the patch antenna operating at 3.5 GHz and the dual-band millimeter-wave antenna operating at 27 GHz and 40 GHz. We take a three-layer ball head model as the human head, and use the COMSOL Multiphysics software to simulate the specific absorption rate (SAR) and the absorbed power density (Sab) and temperature rise performance in the human head. The maximum SAR in human head is 1.41 W/kg and 4.4 W/kg, when it exposed to the microwave antenna and millimeter-wave antenna respectively. The results show that the millimeter-wave antennas have higher radiation energy than the microwave antennas for the human head model. The radiation dose absorbed in the human tissues are all below the limit restriction. © 2022 IEEE.

关键词： Microwave antennas

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Design of Miniaturized Stereo Decoupled Quasi-Yagi Antenna Array by Using SRRs

Design of Miniaturized Stereo Decoupled Quasi-Yagi Antenna A...

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2023 IEEE MTT-S International Wireless Symposium, IWS 2023

作者： Xu, Jin-Jing Zhou, Wen-Ying Lu, Mai Lanzhou Jiaotong University Key Lab of Opto-Electronic Technology and Intelligent Control of Ministry of Education Gansu Lanzhou730070 China

ISBN: (纸本)9798350336535

This paper proposes a miniaturized stereo quasi-Yagi antenna array. When the distance between array elements is 0.16 λ0, the coupling is suppressed using the periodically ordered splitring resonators (SRRs). The simulation results indicate that the isolation of the decoupled antenna array at 2.4 GHz is increased by nearly four times, and the gain is almost unaffected. Meanwhile, the channel capacity of the suggested decoupled quasi-Yagi antenna array reaches 7.999 bps/Hz when the signal-to-noise ratio (SNR) is 20 dB. The effectiveness of our suggested decoupling structure is demonstrated. © 2023 IEEE.

关键词： Antenna arrays

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Hierarchical and Distributed optimal control Strategy for Power and Power Quality of Microgrid Based on Finite-Time Consistency

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Energy Engineering 2022年第5期119卷 2065-2080页

作者： Wenjun Wei Hao Liang College of Automation&Electrical Engineering Lanzhou Jiaotong UniversityLanzhou730070China Key Lab of Opt-Electronic Technology and Intelligent Control of Ministry of Education Lanzhou Jiaotong UniversityLanzhou730070China

Droop control is one of the main control strategies of islanded microgrid(MG),but the droop control cannot achieve reasonable power distribution of microgrid,resulting in frequency and voltage deviation from the rating value,which needs the upper control link to eliminate the ***,at present,most layered control requires a centralized control center,which excessively relies on microgrid central controller(MGCC)and real-time communication among distributed generation(DG),which has certain *** solve the above problems,this paper proposes a hierarchical distributed power and power quality optimization strategy based on multi-agent finite time consistency algorithm(MA-FTCA).Firstly,based on the first layer droop control,MA-FTCA is applied to introduce frequency and voltage compensation to stabilize the system frequency and voltage at the rated ***,in the third layer,the MA-FTCA is adopted to estimate the total active power and total reactive power spare capacity of the system,to realize the reasonable distribution of active power and reactive power output of each DG according to its proportion of spare capacity when the system load side *** control strategy proposed in this paper adopts a completely distributed control method and does not need a centralized control center in each layer of ***,MATlab/Simulink simulation platform is used to verify the correctness and effectiveness of the proposed optimization strategy.

关键词： Microgrid finite time consistency power distribution hierarchical control

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A Dual-function Quasi-static Magnetic Device with Cloaking and Concentrating Functions Simultaneously

A Dual-function Quasi-static Magnetic Device with Cloaking a...

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2024 Photonics and Electromagnetics Research Symposium, PIERS 2024

作者： Chen, Hanchuan Liu, Yichao Sun, Fei Taiyuan University of Technology Key Lab of Advanced Transducers and Intelligent Control System Ministry of Education and Shanxi Province College of Electronic Information and Optical Engineering Taiyuan030024 China

ISBN: (纸本)9798350375909

In previous study, many single-function static/quasi-static magnetic devices, such as cloak and concentrator, have been designed base on transformation optics. However, few have explored devices capable of simultaneously generating two different functions on the static/quasi-static magnetic field. In this study, we propose a dual-function quasi-static magnetic device, which can create a concealed region and concentrated region for quasi-static magnetic field simultaneously. The dual-function quasi-static magnetic device is designed via twice extreme spatial stretching transformation and magnetic null medium, which can be realized by using arrays of superconductors and ferromagnetic materials in specific arrangement. The simulated results verify the performance of the proposed dual-function quasi-static magnetic device, which can simultaneously achieve cloaking and concentrating effect for the magnetic field from DC to 1000 Hz. The quasi-static magnetic field can be enhanced 9 times than the background magnetic field when the side lengths of the internal square pillar and external square pillar of the proposed structure are selected as a = 10 mm and b = 90 mm, respectively. Moreover, the concentrating ratio obtained from theoretical calculation fits well with the results obtained through numerical simulation. The dual-function quasi-static magnetic device designed in this study may have essential application in medical testing for special occasions. © 2024 IEEE.

关键词： Wigglers

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Electromagnetic-acoustic Beam Compressor by Double-physical-fields Null Medium

Electromagnetic-acoustic Beam Compressor by Double-physical-...

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2024 Photonics and Electromagnetics Research Symposium, PIERS 2024

作者： Sun, Ran Sun, Fei Liu, Yichao Zhang, Zeyu Yang, Chao Taiyuan University of Technology Key Lab of Advanced Transducers and Intelligent Control System Ministry of Education and Shanxi Province College of Electronic Information and Optical Engineering Taiyuan030024 China

ISBN: (纸本)9798350375909

In this study, double-physical-fields null medium, i.e., a subwavelength air channels surrounded by a carefully arranged metal plates, is utilized to design an electromagnetic-acoustic beam compressor capable of simultaneously compressing electromagnetic waves and acoustic waves. Numerical simulation results verify its ability to simultaneously produce the expected compression ratios for both electromagnetic waves and acoustic waves. Moreover, the compression ratio precisely matches the geometric size ratio of the input and output planes of the compressor. This work may have potential applications in electromagnetic-acoustic coupling systems and electromagnetic-acoustic processing/detection. © 2024 IEEE.

关键词： Acoustic waves

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