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Current Status and Development Tendency of Wearable Cardiac Health Monitoring

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Chinese Journal of Electrical Engineering 2023年第1期9卷 71-92页

作者： Yifeng Wang Zheng Zhao Jiangtao Li School of Electrical Engineering Xi’an Jiaotong UniversityXi’an 710049China

Wearable cardiac monitoring devices can provide uninterrupted monitoring of cardiac activities over a long period of time.They have developed rapidly in recent years in terms of convenience,comfort,and intelligence.Aided by the development of sensor and materials technology,big data and artificial intelligence,wearable cardiac monitoring can become a crucial basis for novel medical models in the future.Herein,the basic concepts and representative devices of wearable cardiac monitoring are first introduced.Subsequently,its core technologies and the latest representative research progress in physiology signal sensing,signal quality enhancement,and signal reliability are systematically reviewed.Finally,an insight and outlook on the future development trends and challenges of wearable cardiac monitoring are discussed.

关键词： Wearable cardiac monitoring electrocardiogram seismocardiography photoplethysmogram cardiovascular disease

Streamer‐to‐precursor transition in N_(2)-SF_(6)mixtures under positive repetitive submicrosecond pulses

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High Voltage 2022年第2期7卷 382-389页

作者： Zheng Zhao Zhifeng Dai Anbang Sun Jiangtao Li School of Electrical Engineering Xi'an Jiaotong UniversityXi'anChina

The evolution of discharge dynamics in N_(2)-SF_(6)mixtures under long‐term repetitive submicrosecond pulses is investigated based on pulse‐sequence resolved electrical and optical diagnostics.The effects of gas pressure,pulse repetition frequency(PRF),and SF6 concentration on discharge evolutions are determined.The number of applied pulses before breakdown is shown to non‐linearly decrease with increasing PRF for all included gas pressures and SF6 concentrations.A higher SF6 concentration is favourable for increasing relative insulation capability under repetitive pulses.Unexpected complexities of discharge evolutions under repetitive pulses are reported for the first time for the discharge mechanism transition when a strong electronegative gas is introduced.A pulse‐to‐pulse progressive streamer(first discharge)‐to‐precursor(before breakdown)transition is observed in an N_(2)-SF_(6)mixture under positive repetitive pulses and is less dependent on gas pressure than traditional scenarios.The formation of a precursor section is jointly supported by electrical and optical signatures.The discharge mechanism transition and the detour phenomenon under repetitive pulses are discussed based on the effects of space charges on the spatial distribution of the electric field strength.

关键词： breakdown transition second

Repetitively pulsed gas discharges:memory effect and discharge mode transition

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High Voltage 2020年第5期5卷 569-582页

作者： Zheng Zhao Jiangtao Li School of Electrical Engineering Xi'an Jiaotong UniversityXi'anPeople's Republic of China

Repetitively pulsed gas volume and dielectric surface discharges have gained growing attention because of peculiar and exciting physics phenomena,high efficiency,high reactivity,and potential to obtain conventionally unachievable plasma properties.Nevertheless,incomplete understanding of fundamental mechanisms renders the repetitively pulsed discharge far less predictable and controllable,where the inherent memory effect and the discharge mode transition are universal challenges.In this topical review,the authors will explore the macroscopic characteristics of the gas gap breakdown and the surface flashover,state-of-the-art mechanisms and dominant agents of discharge memory effects,operation regimes and transitions of the discharge mode,and how waveform parameters affect the pulsed discharge properties.Challenges and potential approaches for further understanding the memory effect and the discharge mode transition in the repetitively pulsed discharge are discussed.

关键词： properties. transition incomplete

LED Adaptive Deployment Optimization in Indoor VLC Networks

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China Communications 2021年第6期18卷 201-213页

作者： Jiangtao Li Xu Bao Wence Zhang School of Computer Science and Communication Engineering Jiangsu UniversityZhenjiang 212013China

Driven by the continuous penetration of high data rate services and applications,a large amount of unregulated visible light spectrum is used for communication to fully meet the needs of 6th generation(6G)mobile technologies.Visible light communication(VLC)faces many challenges as a solution that complements existing radio frequency(RF)networks.This paper studies the optimal configuration of LEDs in indoor environments under the constraints of illumination and quality of experience(QoE).Based on the Voronoi tessellation(VT)and centroidal Voronoi tessellation(CVT)theory,combined with the Lloyd’s algorithm,we propose two approaches for optimizing LED deployments to meet the illumination and QoE requirements of all users.Focusing on(i)the minimization of the number of LEDs to be installed in order to meet illumination and average QoE constraints,and(ii)the maximization of the average QoE of users to be served with a fixed number of LEDs.Monte Carlo simulations are carried out for different user distribution compared with hexagonal,square and VT deployment.The simulation results illustrate that under the same conditions,the proposed deployment approach can provide less LEDs and achieve better QoE performance.

关键词： visible light communication lightemitting diodes centroidal Voronoi tessellation quality of experience optimal deployment

Highly thermal-conductive graphite flake/Cu composites prepared by sintering intermittently electroplated core-shell powders

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Journal of Materials Science & Technology 2021年第2期61卷 93-99页

作者： Hong Sun Nan Deng Jianqiang li Gang He Jiangtao Li National Engineering Laboratory for Hydrometallurgical Cleaner Production Technology CAS Key Laboratory of Green Process and Engineering.Institute of Process EngineeringChinese Academy of SciencesBeijing100190China University of Chinese Academy of Sciences Beijing100049China School of Materials Science and Engineering University of Science and Technology BeijingBeijing100083China Technical Institute of Physics and Chemistry Chinese Academy of SciencesBeijing100190China

Graphite flake/Cu composite has attracted tremendous attention as a promising heat sinks materials owing to its easy machinability and superior thermal properties. However, its preparation process still faces several technological limitations including complex, time-consuming and costly synthetic approaches. In this work, a facile and scalable intermittently electroplated method is applied to prepare Cu-coated graphite flake composite powders, which are subsequently sintered into dense composite bulks. The results show that the graphite flake is successfully coated with a uniform and compact Cu shell,which effectively inhibits the segregation accumulation of graphite flakes and contributes to homogeneous distribution of graphite in the sintered graphite flake/Cu composites. The as-sintered composites exhibit an excellent thermal conductivity of 710 W·m-1·K-1and an outstanding bending strength of 93 MPa. Such performance, together with the simple, efficient powder-preparation process, suggests that the present strategy may open up opportunities for the development of thermal management materials.

关键词： Graphite flake Electroplating Powder processing Thermal properties

Calcium-magnesium-alumina-silicate(CMAS)resistant high entropy ceramic(Y_(0.2)Gd_(0.2)Er_(0.2)Yb_(0.2)Lu_(0.2))_(2)Zr_(2)O_(7) for thermal barrier coatings

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Journal of Materials Science & Technology 2022年第12期107卷 259-265页

作者： Shuxiang Deng Gang He Zengchao Yang Jingxia Wang Jiangtao Li Lei Jiang Key Laboratory of Cryogenics Technical Institute of Physics and ChemistryChinese Academy of SciencesBeijing 100190China Center of Materials Science and Optoelectronics Engineering University of the Chinese Academy of SciencesBeijing 100049China Key Laboratory of Bio-Inspired Materials and Interface Sciences Technical Institute of Physics and ChemistryChinese Academy of SciencesBeijing 100190China

A novel high-entropy material,(Y_(0.2)Gd_(0.2)Er_(0.2)Yb_(0.2)Lu_(0.2))_(2)Zr_(2)O_(7)was successfully synthesized by the solid state reaction method and spark plasma sintering,and investigated as a promising thermal barrier coating material.Rare-earth elements were distributed homogeneously in the pyrochlore structure.It was found that the prepared high-entropy ceramic maintains pyrochlore structure at the temperature up to 1600℃,and it possesses a similar thermal expansion coefficient(10.2×10^(−6)K^(−1) at 25-900℃)to that of YSZ,low thermal conductivity(<0.9 W m^(-1)K^(−1) at 100-1000℃)and good CMAS resistance(infiltration depth is 22μm after annealed at 1300℃for 24 h).The corrosion process was investigated,and RE elements distributing homogeneously in(Y_(0.2)Gd_(0.2)Er_(0.2)Yb_(0.2)Lu_(0.2))_(2)Zr_(2)O_(7)show different diffusion rates in CMAS.RE^(3+) with a larger radius(closer to Ca^(2+))is easier to react with CMAS to form an apatite phase.

关键词： High-entropy ceramic Pyrochlore structure Thermal barrier coating material CMAS resistance

Exploring exosomes to provide evidence for the treatment and prediction of Alzheimer’s disease

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BIOCELL 2023年第10期47卷 2163-2176页

作者： XIANGYU QUAN XUETING MA GUODONG li XUEQI FU Jiangtao Li liNliN ZENG Edmond H.Fischer Signal Transduction Laboratory School of Life SciencesJilin UniversityChangchun130012China Department of General Surgery The Second Hospital of Jilin UniversityChangchun130041China

Exosomes are extracellular vesicles with a 30–150 nm diameter originating from endosomes.In recent years,scientists have regarded exosomes as an ideal small molecule carrier for the targeted treatment of Alzheimer’s disease(AD)across the blood-brain barrier due to their nanoscale size and low immunogenicity.A large amount of evidence shows that exosomes are rich in biomarkers,and it has been found that the changes in biomarker content in blood,cerebrospinal fluid,and urine are often associated with the onset of AD patients.In this paper,some recent advances in the use of exosomes in the treatment of AD are reviewed,and various exosome markers and some latest detection methods are summarized to provide some evidence for the detection or treatment of AD by exosomes.

关键词： Exosome Alzheimer’s disease Biomarker Medical treatment Medical forecast

Crustal and uppermost mantle structure of the northeastern Qinghai-Xizang Plateau from joint inversion of surface wave dispersions and receiver functions with P velocity constraints

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Earthquake Science 2024年第2期37卷 93-106页

作者： Pei Zhang Xiaodong Song Jiangtao Li Xingchen Wang Xuezhen Zhang Institute of Geophysics China Earthquake AdministrationBeijing 100081China The Second Monitoring and Application Center China Earthquake AdministrationXi'an 710054China Institute of Theoretical and Applied Geophysics School of Earth and Space SciencesPeking UniversityBeijing 100871China Department of Geophysics School of Geodesy and GeomaticsWuhan UniversityWuhan 430079China

lithospheric structure beneath the northeastern Qinghai-Xizang Plateau is of vital significance for studying the geodynamic processes of crustal thickening and expansion of the Qinghai-Xizang Plateau. We conducted a joint inversion of receiver functions and surface wave dispersions with P-wave velocity constraints using data from the Chin Array Ⅱ temporary stations deployed across the Qinghai-Xizang Plateau. Prior to joint inversion, we applied the H-κ-c method(li JT et al., 2019) to the receiver function data in order to correct for the back-azimuthal variations in the arrival times of Ps phases and crustal multiples caused by crustal anisotropy and dipping interfaces. High-resolution images of vS, crustal thickness, and vP/vSstructures in the Qinghai-Xizang Plateau were simultaneously derived from the joint inversion. The seismic images reveal that crustal thickness decreases outward from the Qinghai-Xizang Plateau. The stable interiors of the Ordos and Alxa blocks exhibited higher velocities and lower crustal vP/vSratios. While, lower velocities and higher vP/vSratios were observed beneath the Qilian Orogen and Songpan-Ganzi terrane(SPGZ), which are geologically active and mechanically weak, especially in the mid-lower crust.Delamination or thermal erosion of the lithosphere triggered by hot asthenospheric flow contributes to the observed uppermost mantle low-velocity zones(LVZs) in the SPGZ. The crustal thickness, vS, and vP/vSratios suggest that whole lithospheric shortening is a plausible mechanism for crustal thickening in the Qinghai-Xizang Plateau, supporting the idea of coupled lithospheric-scale deformation in this region.

关键词： joint inversion receiver functions surface waves crustal thickness vP/vS ratio NE Qinghai-Xizang Plateau

The superiority and feasibility of 2,3,5-triphenyltetrazolium chloride-stained brain tissues for molecular biology experiments based on microglial properties

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Animal Models and Experimental Medicine 2023年第2期6卷 111-119页

作者： Yajuan Wang Qingrong Zhang Shuchi Zhang jiangtao Qi li li Department of Anesthesiology Huashan HospitalFudan UniversityShanghaiChina Department of Anesthesiology Tongji HospitalTongji UniversityShanghaiChina

Background:TTC(2,3,5-triphenyltetrazolium chloride)staining is the most commonly used method in identifying and assessing cerebral infarct volumes in the transient middle cerebral artery occlusion model.Given that microglia exhibit different morphologies in different regions after ischemic stroke,we demonstrate the superiority and necessity of using TTC-stained brain tissue to analyze the expression of various proteins or genes in different regions based on microglia character.Methods:We compared brain tissue(left for 10 min on ice)from the improved TTC staining method with penumbra from the traditional sampling method.We identified the feasibility and necessity of the improved staining method using real time(RT)-PCR,Western blot,and immunofluorescence analysis.Results:There was no protein and RNA degradation in the TTC-stained brain tissue group.However,the TREM2 specifically expressed on the microglia showed a significant difference between two groups in the penumbra region.Conclusions:TTC-stained brain tissue can be used for molecular biology experiments without any restrictions.In addition,TTC-stained brain tissue shows greater superiority due to its precise positioning.

关键词： ischemic brain injury microglia transient middle cerebral artery occlusion TTC staining