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Enhancing thermoelectric performance of p-type SnTe through manipulating energy band structures and decreasing electronic thermal conductivity

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Rare Metals 2024年第7期43卷 3232-3241页

作者： Xin Qian Hao-Ran Guo Jia-Xin Lyu Bang-Fu Ding Xing-Yuan San Xiao Zhang Jiang-Long Wang Shu-Fang Wang Hebei Key Lab of Optic-electronic information and Materials College of Physics Science and TechnologyHebei University college of Electron and information engineering Hebei University Research Institute for Frontier science Beihang University

SnTe has received considerable attention as an environmentally friendly alternative to the representative thermoelectric material of ***,excessive hole carrier concentration in SnTe results in an extremely low Seebeck coefficient and high thermal conductivity,which makes it exhibit relatively inferior thermoelectric *** this work,the thermoelectric performance of p-type SnTe is enhanced through regulating its energy band structures and reducing its electronic thermal conductivity by combining Bi doping with CdSe ***,the carrier concentration of SnTe is successfully suppressed via Bi doping,which significantly decreases the electronic thermal ***,the convergence and flattening of the valence bands by alloying CdSe effectively improves the effective mass of SnTe while restraining its carrier ***,a maximum figure of merit（ZT） of～ 0.87 at 823 K and an average ZT of～ 0.51 at 300-823 K have been achieved in Sn0.96Bi0.04Te-5%*** results indicate that decreasing the electronic thermal conductivity is an effective means of improving the performance of thermoelectric materials with a high carrier concentration.

关键词： Thermoelectric materials SnTe Energy band structure electronic thermal conductivity ZT value

Radiation build-up and dissipation in Raman random fiber laser

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science China(information sciences) 2024年第1期67卷 254-260页

作者： Shengtao LIN Zinan WANG Jiaojiao ZHANG Pan WANG Han WU Yifei QI Key Laboratory of Optical Fiber Sensing and Communications University of Electronic Science and Technology of China college of electronics and information engineering Sichuan University

Raman random fiber laser(RRFL) is a complex physical system that arises from the distributed Raman amplification and the intrinsic stochasticity of fiber *** analysis of the underlying lightwave kinetics at steady state has been the focus of considerable ***,the transient state,such as the RRFL build-up and dissipation,is particularly important for revealing the lightwave interaction ***,we investigate for the first time the RRFL dynamics at the transient state and track the RRFL temporal and spectral evolution theoretically and ***,with the contribution of random distributed feedback,RRFL build-up exhibits continuous Verhulst logistic growth curves without cavity-related features,which is significantly different from the step-like growth curve of conventional fiber ***,the radiation build-up duration is inversely related to the pump power,and the spectral evolution of the RRFL undergoes two phases,i.e.,from spectral density increase to spectral *** the steady state to the pump switch-off state,the RRFL output power dissipates immediately,and the remaining Stokes lightwave from the Rayleigh scattering will gradually disappear after one round *** work provides new insights into the transient dynamic features of the RRFL.

关键词： random fiber laser stimulated Raman scattering transient phenomenon nonlinear optics łinebreak biological growth dynamics

Research on Anti-Fluctuation Control of Winding Tension System Based on Feedforward Compensation

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Computer Modeling in engineering & sciences 2024年第5期139卷 1239-1261页

作者： Yujie Duan Jianguo Liang Jianglin Liu Haifeng Gao Yinhui Li Jinzhu Zhang Xinyu Wen college of Mechanical and Vehicle engineering Taiyuan University of TechnologyTaiyuan030024China college of electronic information and Optical engineering Taiyuan University of TechnologyTaiyuan030024China School of electronic information engineering Taiyuan University of Science and TechnologyTaiyuan030000China

In the fiber winding process,strong disturbance,uncertainty,strong coupling,and fiber friction complicate the winding constant tension *** order to effectively reduce the influence of these problems on the tension output,this paper proposed a tension fluctuation rejection strategy based on feedforward *** addition to the bias harmonic curve of the unknown state,the tension fluctuation also contains the influence of bounded noise.A tension fluctuation observer(TFO)is designed to cancel the uncertain periodic signal,in which the frequency generator is used to estimate the critical parameter ***,the fluctuation signal is reconstructed by a third-order auxiliary *** estimated signal feedforward compensates for the actual tension ***,a time-varying parameters fractional-order PID controller(TPFOPID)is realized to attenuate the bounded noise in the ***,TPFOPID is enhanced by TFO and applied to control a tension control system considering multi-source *** stability of the method is analyzed by using the Lyapunov ***,numerical simulations verify that the proposed scheme improves the tracking ability and robustness of the system in response to tension fluctuations.

关键词： Constant tension control anti-fluctuation strategy tension fluctuation observer time-varying parameters fractional-order PID controller feedforward compensate

Triad-displaced ULAs configuration for non-circular sources with larger continuous virtual aperture and enhanced degrees of freedom

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Journal of Systems engineering and electronics 2024年第1期35卷 81-93页

作者： SHAIKH Abdul Hayee DANG Xiaoyu HUANG Daqing college of electronic and information engineering Nanjing University of Aeronautics and AstronauticsNanjing 211106China

Non-uniform linear array(NULA)configurations are well renowned due to their structural ability for providing increased degrees of freedom(DOF)and wider array aperture than uniform linear arrays(ULAs).These characteristics play a significant role in improving the direction-of-arrival(DOA)estimation ***,most of the existing NULA geometries are primarily applicable to circular sources(CSs),while they limitedly improve the DOF and continuous virtual aperture for noncircular sources(NCSs).Toward this purpose,we present a triaddisplaced ULAs(Tdis-ULAs)configuration for *** TdisULAs structure generally consists of three ULAs,which are appropriately *** proposed antenna array approach fully exploits the non-circular characteristics of the *** the same number of elements,the Tdis-ULAs design achieves more DOF and larger hole-free co-array aperture than its sparse array ***,the number of uniform DOF,optimal distribution of elements among the ULAs,and precise element positions are uniquely determined by the closed-form ***,the proposed array also produces a filled resulting *** simulations are conducted to show the performance advantages of the proposed Tdis-ULAs configuration over its counterpart designs.

关键词： direction-of-arrival(DOA)estimation sparse array non-circular source(NCS) sum co-array difference co-array degrees of freedom(DOF)

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Poles Extraction Based LiDAR Localization for Autonomous Robot Systems

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Journal of Systems science & Complexity 2024年第4期37卷 1413-1424页

作者： HONG Xin DONG Yi college of electronic and information engineering Tongji UniversityShanghai 201800China

With the development of intelligent technology,the problem of Li DAR-based localization has played an increasingly important role in the localization of robots in unmanned *** the dense point clouds from the environment requires a large amount of memory,specific and stable structural features,such as pole-like objects in the environment,can serve as the ideal landmarks for localization in unmanned systems,which can effectively reduce the memory usage and mitigate the effects of dynamic environment *** this paper,the authors propose a pole-like objects extraction approach and then,it is applied into the localization system of mobile *** the same experimental conditions,the proposed method can extract more pole-like objects and achieve better long-term localization accuracy than some existing methods in different urban environmental datasets.

关键词： Pole-like landmark extraction robot localization

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Thermogalvanic hydrogel-based e-skin for self-powered on-body dual-modal temperature and strain sensing

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Microsystems & Nanoengineering 2024年第2期10卷 293-302页

作者： Zhaosu Wang Ning Li Xinru Yang Zhiyi Zhang Hulin Zhang Xiaojing Cui college of electronic information and Optical engineering Taiyuan University of TechnologyTaiyuan030024China college of Materials science and engineering Taiyuan University of TechnologyTaiyuan030024China School of Physics and information engineering Shanxi Normal UniversityTaiyuan030031China

Sensing of both temperature and strain is crucial for various diagnostic and therapeutic ***,we present a novel hydrogel-based electronic skin(e-skin)capable of dual-mode sensing of temperature and *** thermocouple ion selected for this study is the iodine/triiodide(I−/I3−)redox couple,which is a common component in everyday *** leveraging the thermoelectric conversion in conjunction with the inherent piezoresistive effect of a gel electrolyte,self-powered sensing is achieved by utilizing the temperature difference between the human body and the external *** composite hydrogels synthesized from polyvinyl alcohol(PVA)monomers using a simple freeze‒thaw method exhibit remarkable flexibility,extensibility,and adaptability to human *** incorporation of zwitterions further augments the resistance of the hydrogel to dehydration and low temperatures,allowing maintenance of more than 90%of its weight after 48 h in the *** its robust thermal current response,the hydrogel was encapsulated and then integrated onto various areas of the human body,including the cheeks,fingers,and ***,the detection of the head-down state and the monitoring of foot movements demonstrate the promising application of the hydrogel in supervising the neck posture of sedentary office workers and the activity *** successful demonstration of self-powered on-body temperature and strain sensing opens up new possibilities for wearable intelligent electronics and robotics.

关键词： hydrogel modal utilizing

A Review of NILM Applications with Machine Learning Approaches

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Computers, Materials & Continua 2024年第5期79卷 2971-2989页

作者： Maheesha Dhashantha Silva Qi Liu School of electronic and information engineering Nanjing University of Information Science and TechnologyNanjing210044China

In recent years,Non-Intrusive LoadMonitoring (NILM) has become an emerging approach that provides affordableenergy management solutions using aggregated load obtained from a single smart meter in the power ***, by integrating Machine Learning (ML), NILM can efficiently use electrical energy and offer less ofa burden for the energy monitoring process. However, conducted research works have limitations for real-timeimplementation due to the practical issues. This paper aims to identify the contribution of ML approaches todeveloping a reliable Energy Management (EM) solution with NILM. Firstly, phases of the NILM are discussed,along with the research works that have been conducted in the domain. Secondly, the contribution of machinelearning approaches in three aspects is discussed: Supervised learning, unsupervised learning, and *** highlights the limitations in the applicability of ML approaches in the field. Then, the challenges in the realtimeimplementation are concerned with six use cases: Difficulty in recognizing multiple loads at a given time,cost of running the NILM system, lack of universal framework for appliance detection, anomaly detection andnew appliance identification, and complexity of the electricity loads and real-time demand side ***, options for selecting an approach for an efficientNILMframework are suggested. Finally, suggestionsare provided for future research directions.

关键词： Non-intrusive load monitoring transfer learning machine learning feature extraction

Optimizing electronic structure of Mo_(2)TiC_(2)T_(x)MXene through Nb doping for enhanced electrochemical performance

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Nano Research 2024年第8期17卷 7174-7181页

作者： Jingyuan Zhao Wenzheng Yan Zhaoxi Liu Xiaobin Liu Yapeng Tian Xinwei Cui Henan Institute of Advanced Technology College of Materials Science and EngineeringZhengzhou UniversityZhengzhou 450003China college of Physics and electronic information engineering Guilin University of TechnologyGuilin 514004China

MXene is a promising electrode material for both high volumetric capacitance and high-rate performance in ***,the current study has mainly focused on the monometallic element Ti_(3)C_(2)T_(x)MXene until now,while the bimetallic and multimetallic MXene have received comparatively less *** this work,we demonstrate that the electronic structure of the Mo_(2)TiC_(2)T_(x)MXene could be regulated by fine-tuning the content of doped Nb *** enhanced electron cloud density of surface–O termination and the electron spin of the Mo atoms in the Mo_(2)TiC_(2)T_(x)MXene,leads to the boost of electric double-layer capacitor(EDLC)and improvement of *** a consequence,the electrochemical performance of Nb-doped Mo_(2)TiC_(2)T_(x)MXene(Nb-0.3-MXene)demonstrates a capacitance of 398 F·cm^(−3),roughly doubling that of the pristine Mo_(2)TiC_(2)T_(x)MXene electrode at 197 F·cm^(−3)in the 3 M H_(2)SO_(4)*** the same time,the Nb-0.3-MXene could even maintain a capacitance of 82.75%at 200 mV·s−1,with high cyclic stability for 19,000 cycles at 10 A·g−***,Nb-0.3-MXene-based hybrid supercapacitors deliver a remarkable volumetric energy density of 48.1 W·h·L^(−1)at 230.7 W·L^(−1),and 34.4 W·h·L^(−1)at a high power density of 82.6 kW·L^(−1).There exists a balance between the volumetric capacitance and rate performance with different ratios of Nb atoms in the Nb-doped MXene due to the strong interaction between the Nb-doped MXene and the intercalated ***,optimizing the electronic structure of MXene through heteroatom doping is of great potential for enhanced supercapacitor performance.

关键词： niobium doping electronic structure Mo_(2)TiC_(2)T_(x)MXene electron spin rate performance volumetric capacitance

Rapid Phase Ambiguity Elimination Methods for DOA Estimator via Hybrid Massive MIMO Receive Array

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Chinese Journal of electronics 2024年第1期33卷 175-184页

作者： Xichao ZHAN Zhongwen SUN Feng SHU Yiwen CHEN Xin CHENG Yuanyuan WU Qi ZHANG Yifan LI Peng ZHANG School of information and Communication engineering Hainan University School of electronic and Optical engineering Nanjing University of Science and Technology

For a sub-connected hybrid multiple-input multiple-output(MIMO) receiver with K subarrays and N antennas, there exists a challenging problem of how to rapidly remove phase ambiguity in only single time-slot. A direction of arrival(DOA) estimator of maximizing received power(Max-RP) is proposed to find the maximum value of K-subarray output powers, where each subarray is in charge of one sector, and the center angle of the sector corresponding to the maximum output is the estimated true DOA. To make an enhancement on precision, Max-RP plus quadratic interpolation(Max-RP-QI) method is designed. In the proposed Max-RP-QI, a quadratic interpolation scheme is adopted to interpolate the three DOA values corresponding to the largest three receive powers of *** achieve the Cramer Rao lower bound, a Root-MUSIC plus Max-RP-QI scheme is developed. Simulation results show that the proposed three methods eliminate the phase ambiguity during one time-slot and also show low computational complexities. The proposed Root-MUSIC plus Max-RP-QI scheme can reach the Cramer Rao lower bound,and the proposed Max-RP and Max-RP-QI are still some performance losses 2–4 d B compared to the Cramer Rao lower bound.

关键词： Phased arrays Interpolation Wireless sensor networks Direction-of-arrival estimation Simulation Receiving antennas Massive MIMO

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