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Hybrid pedestrian positioning system using wearable inertial sensors and ultrasonic ranging

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Defence Technology（防务技术） 2024年第3期33卷 327-338页

作者： lin Qi yu liu Chuanshun Gao Tao Feng yue yu School of Communication and Information Engineering Chongqing University of Posts and TelecommunicationsChongqing 400065China Department of Land Surveying and Geo-Informatics The Hong Kong Polytechnic UniversityHong Kong 999077China

Pedestrian positioning system(PPS)using wearable inertial sensors has wide applications towards various emerging fields such as smart healthcare,emergency rescue,soldier positioning,*** performance of traditional PPS is limited by the cumulative error of inertial sensors,complex motion modes of pedestrians,and the low robustness of the multi-sensor collaboration *** paper presents a hybrid pedestrian positioning system using the combination of wearable inertial sensors and ultrasonic ranging(H-PPS).A robust two nodes integration structure is developed to adaptively combine the motion data acquired from the single waist-mounted and foot-mounted node,and enhanced by a novel ellipsoid constraint *** addition,a deep-learning-based walking speed estimator is proposed by considering all the motion features provided by different nodes,which effectively reduces the cumulative error originating from inertial ***,a comprehensive data and model dual-driven model is presented to effectively combine the motion data provided by different sensor nodes and walking speed estimator,and multi-level constraints are extracted to further improve the performance of the overall *** results indicate that the proposed H-PPS significantly improves the performance of the single PPS and outperforms existing algorithms in accuracy index under complex indoor scenarios.

关键词： Pedestrian positioning system Wearable inertial sensors Ultrasonic ranging Deep-learning Data and model dual-driven

High-Superelasticity NiTi Shape Memory Alloy by Directed Energy Deposition-Arc and Solution Heat Treatment

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Acta Metallurgica Sinica(English Letters) 2024年第1期37卷 132-144页

作者： Junyi Ma lin yu Qing Yang Jie liu Lei Yang State Key Laboratory of Materials Processing and Die&Mould Technology School of Materials Science and EngineeringHuazhong University of Science and TechnologyWuhan430070China School of Transportation and Logistics Engineering Wuhan University of TechnologyWuhan430074China

Directed energy deposition-arc(DED-Arc)technology has the advantages of simple equipment,low manufacturing cost and high deposition rate,while the use of DED-Arc has problems of microstructure inhomogeneity,position dependence of macroscopic mechanical properties and ***,it is necessary to carry out a subsequent heat treatment to improve its microstructure uniformity,mechanical properties and *** this investigation,the DED-Arc 15-layer NiTi alloy thin-walled parts with the solution treatment at different process parameters were studied to analyze the effects of solution heat treatment on microstructure,phase composition,phase transformation,microhardness,tensile and *** temperature range of solution treatment is 800-1050℃,and the treatment time range is 1-5.5 *** results show that after solution treatment at 800℃/1 h,the content of precipitated phase decreases,the grain is refined,the microhardness increases,and the mechanical properties in the 0°direction are *** strain recovery rate after 10 tensile cycles has increased from 37.13%(as-built)to 49.25%(solid solution treatment).This research provides an effective post treatment method for high-performance DED-Arc NiTi shape memory alloys.

关键词： Directed energy deposition-arc(DED-Arc) Cold metal transfer(CMT) NiTi shape memory alloys Microstructure Phase transformation Solution heat treatment

Ferroelectric-controlled graphene plasmonic surfaces for all-optical neuromorphic vision

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Science China(Technological Sciences) 2024年第3期67卷 765-773页

作者： CHEN JianBo liu yu LI ShangDong lin lin LI YaDong HUANG Wen GUO JunXiong School of Electronic Information and Electrical Engineering Institute for Advanced StudyChengdu UniversityChengdu 610106China School of Integrated Circuits Tsinghua UniversityBeijing 100084China School of Integrated Circuits(National Exemplary Schoolof Microelectronics) Universityof Electronic Science and Technologyof China Chengdu 610054China Jincheng Research Institute of Opto-mechatronics Industry Jincheng 048000China Shanxi Key Laboratory of Advanced Semiconductor Optoelectronic Devices and Integrated Systems Jincheng 048000China Engineering Research Center of Digital Imaging and Display Ministry of EducationSoochow UniversitySuzhou 215006China

Artificial visual systems can recognize desired objects and information from complex environments, and are therefore highly desired for pattern recognition, object detection, and imaging applications. However, state-of-the-art artificial visual systems with high recognition performances that typically consist of electronic devices face the challenges of requiring huge storage space and high power consumption owing to redundant data. Here, we report a terahertz(THz) frequency-selective surface using a graphene split-ring resonator driven by ferroelectric polarization for efficient visual system applications. The downward polarization of the ferroelectric material offers an ultrahigh electrostatic field for doping p-type graphene with an anticipated Fermi level. By optimizing the geometric parameters of the devices and modulating the carrier behaviors of graphene, our plasmonic devices exhibit a tunable spectral response in a range of 1.7–6.0 THz with continuous transmission values. The alloptical neural network using graphene plasmonic surfaces designed in this study exhibited excellent performance in visual preprocessing and convolutional filtering and achieved an ultrahigh recognition accuracy of up to 99.3% in training the Modified National Institute of Standards and Technology(MNIST) handwritten digit dataset. These features demonstrate the great potential of graphene plasmonic devices for future smart artificial vision systems.

关键词： graphene plasmon ferroelectric frequency selective surface artificial vision system

Spatiotemporal variation of land surface temperature and its driving factors in Xinjiang,China

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Journal of Arid Land 2024年第3期16卷 373-395页

作者： ZHANG Mingyu CAO yu ZHANG Zhengyong ZHANG Xueying liu lin CHEN Hongjin GAO yu yu Fengchen liu Xinyi College of Sciences Shihezi UniversityShihezi 832000China Key Laboratory of Oasis Town and Mountain-Basin System Ecology Xinjiang Production and Construction CorpsShihezi 832000China Yantai Institute of Coastal Zone Research Chinese Academy of SciencesYantai 264003China

Land surface temperature(LST) directly affects the energy balance of terrestrial surface systems and impacts regional resources, ecosystem evolution, and ecosystem structures. Xinjiang Uygur Autonomous Region is located at the arid Northwest China and is extremely sensitive to climate change. There is an urgent need to understand the distribution patterns of LST in this area and quantitatively measure the nature and intensity of the impacts of the major driving factors from a spatial perspective, as well as elucidate the formation mechanisms. In this study, we used the MOD11C3 LST product developed on the basis of Moderate Resolution Imaging Spectroradiometer(MODIS) to conduct regression analysis and determine the spatiotemporal variation and differentiation pattern of LST in Xinjiang from 2000 to 2020. We analyzed the driving mechanisms of spatial heterogeneity of LST in Xinjiang and the six geomorphic zones(the Altay Mountains, Junggar Basin, Tianshan Mountains, Tarim Basin, Turpan-Hami(Tuha) Basin, and Pakakuna Mountain Group) using geographical detector(Geodetector) and geographically weighted regression(GWR) models. The warming rate of LST in Xinjiang during the study period was 0.24℃/10a, and the spatial distribution pattern of LST had obvious topographic imprints, with 87.20% of the warming zone located in the Gobi desert and areas with frequent human activities, and the cooling zone mainly located in the mountainous areas. The seasonal LST in Xinjiang was at a cooling rate of 0.09℃/10a in autumn, and showed a warming trend in other seasons. Digital elevation model(DEM), latitude, wind speed, precipitation, normalized difference vegetation index(NDVI), and sunshine duration in the single-factor and interactive detections were the key factors driving the LST changes. The direction and intensity of each major driving factor on the spatial variations of LST in the study area were heterogeneous. The negative feedback effect of DEM on the spatial differentiation o

关键词： land surface temperature MOD11C3 climate change geographical detector(Geodetector) geographically weighted regression(GWR) source-sink effect Xinjiang

MiR-214-3p Prevents the Development of Perioperative Neurocognitive Disorders in Elderly Rats

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Current Medical Science 2022年第4期42卷 871-884页

作者： yu-hao WANG Yong-wang CHEN Wan-li XIAO Xue-lian LI Lan FENG yu-lin liu Xiao-xia DUAN Department of Anesthesiology the Affiliated Hospital of Southwest Medical UniversityLuzhou 646000China Laboratory of Anesthesiology Southwest Medical UniversityLuzhou 646000China Department of Anesthesiology Southwest Medical UniversityLuzhou 646000China

Objective:This study aimed to identify microRNAs(miRNAs)involved in the development of perioperative neurocognitive disorders(PND).Methods:Plasma exosomal miRNA expression was examined in patients before and after cardiopulmonary bypass(CPB)using microarray and qRT-PCR and these patients were diagnosed as PND *** rats were subjected to CPB,and the cognitive functions were *** analysis was conducted to predict the targets of *** were administered rno-miR-214-3p agomir before or after CPB to investigate the role of miR-214-3p in PND ***:We identified 76 differentially expressed plasma exosomal miRNAs in PND patients after surgery(P0.58),including the upregulated hsa-miR-214-3p(P=0.002399392).Prostaglandin-endoperoxide synthase 2(PTGS2)was predicted as a miR-214-3p *** rats,CPB reduced the platform crossing numbers and target quadrant stay time,accompanied with hippocampal neuronal *** rno-miR-214-3p level was significantly increased in plasma exosomes but decreased in rat hippocampus after surgery,exhibiting a negative correlation(Pling contributes to the development of PND,serving as a potential therapeutic target for PND.

关键词： perioperative neurocognitive disorder sexosome hippocampus miR-214-3p prostaglandin-endoperoxide synthase 2

Effects of shore-normal coastal structure on medium-to long-term embayed shoreline evolution

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Acta Oceanologica Sinica 2024年第2期43卷 58-66页

作者： Jitao yu yuanting Ding Pei liu Renfu Fan lin Zhang Hainan Academy of Ocean and Fisheries Sciences Haikou 571126China Yazhou Bay Innovation Institute Hainan Tropical Ocean UniversitySanya 572025China School of Geography and Environmental Sciences Hainan Normal UniversityHaikou 571158China

Based on high-tide shoreline data extracted from 87 Landsat satellite images from 1986 to 2019 as well as using the linear regression rate and performing a Mann-Kendall(M–K)trend test,this study analyzes the linear characteristics and nonlinear behavior of the medium-to long-term shoreline evolution of Jinghai Bay,eastern Guangdong *** particular,shoreline rotation caused by a shore-normal coastal structure is *** results show that the overall shoreline evolution over the past 30 years is characterized by erosion on the southwest beach,with an average erosion rate of 3.1 m/a,and significant accretion on the northeast beach,with an average accretion rate of 5.6 m/*** of the M–K trend test indicate that significant shoreline changes occurred in early 2006,which can be attributed to shore-normal *** to that engineering construction,the shorelines are slightly eroded,where the average erosion rate is 0.7 m/***,after shore-normal engineering is performed,the shoreline is characterized by significant erosion(3.2 m/a)on the southwest beach and significant accretion(8.5 m/a)on the northeast beach,thus indicating that the shore-normal engineering at the updrift headland contributes to clockwise shoreline *** analysis shows that the clockwise shoreline rotation is promoted not only by longshore sediment transport processes from southwest to northeast,but also by cross-shore sediment transport *** findings are crucial for beach erosion risk management,coastal disaster zoning,regional sediment budget assessments,and further observations and predictions of beach morphodynamics.

关键词： shoreline rotation non-linear behavior longshore sediment transport cross-shore sediment transport embayed beach coastal structure

Self-Driven Photo-Polarized Water Molecule-Triggered Graphene-Based Photodetector

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Research 2024年第2期2023卷 273-283页

作者： Shisheng lin Chang liu Xin Chen Yi Zhang Hongtao lin Xutao yu yujiao Bo Yanghua Lu College of Information Science and Electronic Engineering Zhejiang UniversityHangzhou 310027P.R.China Hangzhou Gelanfeng Technology Co.Ltd Hangzhou 310051P.R.China State Key Laboratory of Modern Optical Instrumentation Zhejang UniversityHangzhou 310027P.R.China Key Laboratory of Wide Bandgap Semiconductor Materials and Devices HCSemitek CorporationYiwu 322009P.R.China Smart Materials for Architecture Research Lab Innovation Center of Yangtze River DeltaZhejiang UniversityJiaxing 314100P.R.China

Flowing water can be used as an energy source for generators,providing a major part of the energy for daily ***,water is rarely used for information or electronic ***,we present the feasibility of a polarized liquid-triggered photodetector in which polarized water is sandwiched between graphene and a *** to the polarization and depolarization processes of water molecules driven by photogenerated carriers,a photo-sensitive current can be repeatedly produced,resulting in a high-performance *** response wavelength of the photodetector can be fine-tuned as a result of the free choice of semiconductors as there is no requirement of lattice match between graphene and the *** zero voltage bias,the responsivity and specific detectivity of Gr/NaCl(0.5 M)W/N-GaN reach values of 130.7 mA/W and 2.3×10^(9)Jones under 350 nm illumination,***,using a polar liquid photodetector can successfully read the photoplethysmography signals to produce accurate oxygen blood saturation and heart *** with the commercial pulse oximetry sensor,the average errors of oxygen saturation and heart rate in the designed photoplethysmography sensor are~1.9%and~2.1%,*** study reveals that water can be used as a high-performance photodetector in informative industries.

关键词： polarization polarized saturation

Cross section determination of^(27)Al(n,2n)^(26)Al reaction induced by 14-MeV neutrons uniting with D-T neutron activation and AMS techniques

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Nuclear Science and Techniques 2024年第6期35卷 78-89页

作者： Xian-lin Yang Chang-lin Lan yu-Ting Wei Yi Zhang Gong Jiang Bo Xie yu liu Hong-Tao Shen Xiao-Jun Sun School of Nuclear Science and Technology Lanzhou UniversityLanzhou 730000China MOE Frontiers Science Center for Rare Isotopes Lanzhou UniversityLanzhou 730000China State Key Laboratory of Environmental Geochemistry Institute of GeochemistryChinese Academy of SciencesGuiyang 550081China Guangxi Key Laboratory of Nuclear Physics and Nuclear Technology Guangxi Normal UniversityGuilin 541004China

Aluminum is the primary structural material in nuclear engineering,and its cross section induced by 14-MeV neutrons is of great *** address the issue of insufficient accuracy for the^(27)Al(n,2n)^(26)Al reaction cross section,the activation method and accelerator mass spectrometry(AMS)technique were used to determine the^(27)Al(n,2n)^(26)Al cross section,which could be used as a D-T plasma ion temperature monitor in fusion *** the China Academy of Engineering Physics,neutron activation was performed using a K-400 neutron generator produced by the T(d,n)4He ***^(26)Al∕^(27)Al isotope ratios were measured using the newly installed GYIG 1 MV AMS at the Institute of Geochemistry,Chinese Academy of *** neutron flux was monitored by measuring the activity of 92mNb produced by the 93Nb(n,2n)92mNb *** measured results were compared with available data in the experimental nuclear reaction database,and the measured values showed a reasonable degree of consistency with partially available literature *** newly acquired cross-sectional data at 12 neutron energy points through systematic measurements clarified the divergence,which has two different growth trends from the existing experimental *** obtained results are also compared with the corresponding evaluated database,and the newly calculated excitation functions with TALYS−1.95 and EMPIRE−3.2 codes,the agreement with CENDL−3.2,TENDL-2021 and EMPIRE−3.2 results are generally acceptable.A substantial improvement in the knowledge of the^(27)Al(n,2n)^(26)Al reaction excitation function was obtained in the present work,which will lay the foundation for the diagnosis of the fusion ion temperature,testing of the nuclear physics model,evaluation of nuclear data,etc.

关键词： 14-MeV neutron ^(27)Al(n,2n)^(26)Al Cross section AMS

Recent Advances of Nanoelectrodes for Single-Cell Electroanalysis:From Extracellular, Intercellular to Intracellular

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Journal of Analysis and Testing 2022年第2期6卷 178-192页

作者： yu-lin liu yu-Xiang Zhao Ya-Bei Li Zhao-Yang Ye Jun-Jie Zhang Yan Zhou Tian-Yang Gao Fei Li The Key Laboratory of Biomedical Information Engineering of Ministry of Education School of Life Science and TechnologyXi’an Jiaotong UniversityXi’an 710049China Bioinspired Engineering and Biomechanics Center(BEBC) Xi’an Jiaotong UniversityXi’an 710049China School of Chemistry Xi’an Jiaotong UniversityXi’an 710049China

Detection at single-cell level plays a critical role in revealing cell behavior in different *** with high temporal–spatial resolution can precisely and dynamically monitor the physiological and pathological processes of various single *** field of using nanoelectrodes in single-cell electroanalysis is blooming in recent *** this review,we mainly summarize the recent advances of nanoelectrodes for single-cell electroanalysis from extracellular,intercellular to intracellular levels in the past ***,we introduce the main types of nanoelectrodes based on their geometry and characteristics for single-cell ***,the representative works of using nanoelectrodes to investigate cellular signaling biomolecules and to understand various cellular processes from the extracellular,intercellular,and intracellular levels are ***,the challenges and future prospects of nanoelectrodes for single-cell electroanalysis are *** review gives a comprehensive summary of nanoelectrodes for single-cell electroanalysis in the prospects of monitoring cell physiological topography,understanding communication mechanism and revealing physiological functions,which can provide new insights into cell-based pharmacological screening and fundamental studies of disease development mechanisms.

关键词： Nanoelectrode Single-cell electroanalysis Extracellular Intercellular Intracellular