检索结果-南通市图书馆

Characterising acute ischaemic stroke thrombi:insights from histology,imaging and emerging Impedance-based technologies

引用

Stroke & Vascular Neurology 2022年第4期7卷 353-363页

作者： Smita Patil Jean Darcourt Pierluca Messina Franz Bozsak Christophe Cognard Karen Doyle CÚRAM SFI Research Centre for Medical DevicesNational University of Ireland GalwayGalwayIreland Neuroradiology CHU de ToulouseToulouseFrance Sensome MassyFrance Physiology National University of Ireland GalwayGalwayIreland

Treatment of acute ischaemic stroke(AIS)focuses on rapid recanalisation of the occluded artery.In recent years,advent of mechanical thrombectomy devices and new procedures have accelerated the analysis of thrombi retrieved during the endovascular thrombectomy procedure.Despite ongoing developments and progress in AIS imaging techniques,it is not yet possible to conclude definitively regarding thrombus characteristics that could advise on the probable efficacy of thrombolysis or thrombectomy in advance of treatment.Intraprocedural devices with dignostic capabilities or new clinical imaging approaches are needed for better treatment of AIS patients.In this review,what is known about the composition of the thrombi that cause strokes and the evidence that thrombus composition has an impact on success of acute stroke treatment has been examined.This review also discusses the evidence that AIS thrombus composition varies with aetiology,questioning if suspected aetiology could be a useful indicator to stroke physicians to help decide the best acute course of treatment.Furthermore,this review discusses the evidence that current widely used radiological imaging tools can predict thrombus composition.Further use of new emerging technologies based on bioImpedance,as imaging modalities for diagnosing AIS and new medical device tools for detecting thrombus composition in situ has been introduced.Whether bioImpedance would be beneficial for gaining new insights into in situ thrombus composition that could guide choice of optimum treatment approach is also reviewed.

关键词： throm acute Impedance

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

High-frequency Resonance Analysis and Impedance Reshaping Control of MMC-HVDC System Based on Frequency Coupling Impedance Model

引用

JOURNAL OF MODERN POWER SYSTEMS AND CLEAN ENERGY 2024年第2期12卷 646-657页

作者： Wang, Juanjuan Chen, Wei Liu, Yuekun Fu, Chuang Ye, Yunming Feng, Junjie South China Univ Technol Sch Elect Power Guangzhou Peoples R China Guangdong Power Grid Co Ltd Guangzhou Peoples R China Elect Power Res Inst China Southern Power Grid Guangzhou Peoples R China

In recent years, high-frequency resonance (HFR) events occurred in several modular multilevel converter based high-voltage direct current (MMC-HVDC) projects. The time delay of an MMC-HVDC system is the critical factor that induces HFR. The frequency coupling affects the Impedance characteristics of an MMC and further deteriorates system stability. Therefore, in this paper, a multi-input multi-output admittance model of an MMC-HVDC system is developed to analyze its frequency characteristics. The effects of current loop, power loop, phase-locked loop, and operating point on the MMC frequency coupling degree are analyzed in detail. Meanwhile, to further suppress HFR in the MMC-HVDC system, an enhanced Impedance reshaping control strategy based on the equivalent single-input single-output Impedance model is proposed. Finally, the accuracy of the enhanced Impedance model and the effectiveness of the Impedance reshaping control are verified by electromagnetic transient simulations in PSCAD.

关键词： Impedance Couplings Power system stability Phase locked loops Frequency control Resonant frequency Damping Modular multilevel converter based high-voltage direct current (MMC-HVDC) high-frequency resonance frequency coupling Impedance model Impedance reshaping control GRID-CONNECTED INVERTER STABILITY ANALYSIS

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Multi‐type defect detection and location based on non‐destructive Impedance spectrum measurement for underground power cables

引用

High Voltage 2023年第5期8卷 977-985页

作者： Jingang Su Liqiang Wei Peng Zhang Yan Li Yunpeng Liu Electric Power Research Institute of State Grid Hebei Electric Power Supply Co.Ltd. ShijiazhuangChina School of Electrical and Electronic Engineering North China Electric Power UniversityBaodingChina

Power cable defect detection and location is a crucial aspect in power asset maintenance.Impedance spectrum measurement can be used as a non‐destructive tool for cable monitoring.Defects from overheating and moisture ingress are investigated by the authors,and it is shown that multi‐type cable defects can be detected and located by this methodology.With both electromagnetic analysis and experimental investigation,the relation between Impedance variation and the dielectric permittivity is studied to reveal the method's mechanism.An approach to implement such Impedance measurement online is proposed and its perspectives in terms of sensitivity is investigated by field scale tests.It is shown that 2%Impedance variation due to defect should be detectable.Field scale tests show perspectives for online application with signal coupling through a highfrequency current transformer with focus on the differences in waveforms obtained from the Impedance measurements.

关键词： power Impedance defect

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Broadband Impedance spectrum detection of buffer layer defects in 110 kV crosslinked polyethylene cable with corrugated aluminium sheath

引用

High Voltage 2023年第5期8卷 967-976页

作者： Yanpeng Hao Peng Zhao Baojun Hui Yanting Cheng Wenbo Zhu Mingli Fu Xiaodong Li School of Electric Power Engineering South China University of TechnologyGuangzhouChina China Southern Power Grid Electric Power Research Institute Co.Ltd GuangzhouChina

The buffer layer defects of high‐voltage crosslinked polyethylene(XLPE)cable occur frequently,which makes the detection method become the focus to be studied.Here,the broadband Impedance detection technology for the buffer layer defects of high‐voltage XLPE cables with corrugated aluminium sheath is investigated.There are nine cable samples,including new and defective ones.Some of the defective cables are artificial,and the other is retired cables.The influence of wiring mode,the circumferential relative position of electrodes,cable length,artificial white powder,artificial damp,and retired defective cables on the Impedance spectrum is studied.It is found that the wiring mode of the insulation shield/aluminium sheath at the end of the cable can effectively detect the buffer layer defects.And the broadband Impedance amplitude spectrum of the buffer layer in defective cable,measuring at various circumferential relative positions,is obviously different.When there are white powders,air gaps,or ablation in the buffer layer,the broadband Impedance spectrum(BIS)will increase by several times.When the buffer layer is damped,the BIS will reduce.The research here provides theoretical support and technical methods for the buffer layer defects of XLPE cable with corrugated aluminium sheath.

关键词： Impedance spectrum layer

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Analysis of 3.4 Ah lithium-sulfur pouch cells by electrochemical Impedance spectroscopy

引用

Journal of Energy Chemistry 2022年第9期31卷 318-325,I0009页

作者： Dominika Capkova Vaclav Knap Andrea Strakova Fedorkova Daniel-Ioan Stroe Department of Physical Chemistry Pavol Jozef Safarik University in KosiceKosice 04154Slovak Republic Faculty of Electrical Engineering Czech Technical University in PraguePrague 16627Czech Republic Department of Energy Technology Aalborg UniversityAalborg East 9220Denmark

Despite great progress in lithium-sulfur(Li-S) batteries, the electrochemical reactions in the cell are not yet fully understood. Electrode processes, complex interfaces and internal resistance may be characterized by electrochemical Impedance spectroscopy(EIS). EIS is a non-destructive technique and easy to apply, though there are challenges in ensuring the reproducibility of measurements and the interpretation of Impedance data. Here, we present the Impedance behavior of a 3.4 Ah Li-S pouch cell characterized by EIS. The Impedance changes were analyzed over the entire depth-of-discharge, depth-of-charge,and at various temperatures. Based on the formation of intermediates during(dis)charging, the changes of resistances are observed. Overall, the increase in temperature causes a decrease in electrolyte viscosity,lowering the surface energy which can improve the penetration of the electrolyte into the electrode pores. Moreover, the effect of superimposed AC current during EIS measurement was analyzed, and the results show the dependence of the charge transfer resistance on superimposed AC current which was lower compared to steady-state conditions and consents with theory.

关键词： Lithium-sulfur battery Impedance Equivalent circuit Temperature dependencies Charging/discharging differences Dynamic electrochemical Impedance spectroscopy

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

A comparison of deep learning methods for seismic Impedance inversion

引用

Petroleum Science 2022年第3期19卷 1019-1030页

作者： Si-Bo Zhang Hong-Jie Si Xin-Ming Wu Shang-Sheng Yan Huawei Cloud EI Product Department Xi'anShaanxi710077China School of Earth and Space Sciences University of Science and Technology of ChinaHefeiAnhui230026China

Deep learning is widely used for seismic Impedance inversion,but few work provides in-depth research and analysis on designing the architectures of deep neural networks and choosing the network hyperparameters.This paper is dedicated to comprehensively studying on the significant aspects of deep neural networks that affect the inversion results.We experimentally reveal how network hyperparameters and architectures affect the inversion performance,and develop a series of methods which are proven to be effective in reconstructing high-frequency information in the estimated Impedance model.Experiments demonstrate that the proposed multi-scale architecture is helpful to reconstruct more high-frequency details than a conventional network.Besides,the reconstruction of high-frequency information can be further promoted by introducing a perceptual loss and a generative adversarial network from the computer vision perspective.More importantly,the experimental results provide valuable references for designing proper network architectures in the seismic inversion problem.

关键词： Seismic inversion Impedance Deep learning Network architecture

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Ultrasensitive photochromism and Impedance dual response to weak visible light by solvated Pb(Ⅱ) modified polyoxomolybdate

引用

Chinese Chemical Letters 2023年第2期34卷 567-571页

作者： Jiayuan Zhang Xinyu Wang Gui Wang Yi Feng Chunhui Zhang Tao Pang Guanggang Gao Linlin Fan Hong Liu School of Materials Science and Engineering University of JinanJinan 250022China College of Pharmacy Jiamusi UniversityJiamusi 154007China

Polyoxometalates (POMs) are important inorganic photochromic materials to be potentially applied in photo-induced switch,energy storage,and even the detection of light.However,due to the limited sensitivity of POMs,it is difficult to realize the photochromic response to weak visible light.In this paper,by the coordination of solvated Pb(Ⅱ),a new structure-defined chain-like polyoxomolybdate complex of[(Pb(DMF)_(4))^(3)(P_(2)Mo_(18)O_(62))_(2)]n(Pb_(3)Mo_(18) ,DMF=dimethylformamide) has been demonstrated by a facile solvent-diffusion approach.By virtue of interactions between Pb(DMF)_(4) and polyoxoanions,Pb_(3)Mo_(18) shows an ultrasensitive photochromic response to weak visible lights and forms the reduced’heteropoly blue’species through ligand-to-metal charge transfer (LMCT) process.A new mechanism is firstly proposed here that the 6s orbital lone electron pair on Pb(II) can effectively stabilize the generated hole of oxygen atoms as a result of O→Mo charge transfer.Through the proposed mechanism,the LMCT barrier is drastically lowered and allows the coloration to be occurred even upon weak visible light.Also,because the conductivity of Pb_(3)Mo_(18) enhances with the increase of reduction extent,its electrochemical Impedance signals are proportionally response to irradiation intensity.Especially,for the first time,the polyoxomolybdate composite can be used to detect weak visible light,in which the optical signal can be converted into electrical signal output.Moreover,Pb_(3)Mo_(18) can be drip-coated on the surface of the screen printed chip electrode,which is facile to the detection of light by portable devices compatible with computers,mobile phones and other electronic equipment.This work not only highlights a new approach to the molecular design of photochromic POMs by the coordination of metal ions with the effect of inert electron pair,but also lays a foundation to extend the application of POMs as light signal sensors.

关键词： Photochromism Polyoxometalate Impedance Visible light Screen printed chip

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Electrical Impedance tomography for clinical application

引用

Science China(Technological Sciences) 2022年第6期65卷 1433-1434页

作者： XU ShaoFeng SHI Yan CAI MaoLin QI HaiTao WANG YiXuan School of Automation Science and Electrical Engineering Beihang UniversityBeijing 100191China Engineering Training Centre Beihang UniversityBeijing 100191China

In the course of the disease,the functional changes of the tissues and organs associated with the condition often predate the disease of its organic nature.If these functional changes can be detected and confirmed by the specific imaging means in the incubation period or the functional compensation period of the disease,that is,before the structural changes in the tissues or organs。

关键词： organs clinical Impedance

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

High-resolution Impedance mapping using electrically activated quantitative phase imaging

引用

Light(Science & Applications) 2021年第2期10卷 186-196页

作者： Cristina Polonschii Mihaela Gheorghiu Sorin David Szilveszter Gáspár Sorin Melinte Hassaan Majeed Mikhail E.Kandel Gabriel Popescu Eugen Gheorghiu International Centre of Biodynamics 060101 BucharestRomania Institute of Information and Communication Technologies Electronics and Applied MathematicsUniversite Catholique de Louvain1348 Louvain-la-NeuveBelgium Quantitative Light Imaging Laboratory Beckman Institute for Advanced Science and TechnologyUniversity of Illinois at Urbana-ChampaignUrbanaIL 61801USA

Retrieving electrical Impedance maps at the nanoscale rapidly via nondestructive inspection with a high signal-to-noise ratio is an unmet need,likely to impact various applications from biomedicine to energy conversion.In this study,we develop a multimodal functional imaging instrument that is characterized by the dual capability of Impedance mapping and phase quantitation,high spatial resolution,and low temporal noise.To achieve this,we advance a quantitative phase imaging system,referred to as epi-magnified image spatial spectrum microscopy combined with electrical actuation,to provide complementary maps of the optical path and electrical Impedance.We demonstrate our system with high-resolution maps of optical path differences and electrical Impedance variations that can distinguish nanosized,semi-transparent,structured coatings involving two materials with relatively similar electrical properties.We map heterogeneous interfaces corresponding to an indium tin oxide layer exposed by holes with diameters as small as~550 nm in a titanium(dioxide)over-layer deposited on a glass support.We show that electrical modulation during the phase imaging of a macro-electrode is decisive for retrieving electrical Impedance distributions with submicron spatial resolution-and beyond the limitations of electrode-based technologies(surface or scanning technologies).The findings,which are substantiated by a theoretical model that fits the experimental data very well enable achieving electro-optical maps with high spatial and temporal resolutions.The virtues and limitations of the novel optoelectrochemical method that provides grounds for a wider range of electrically modulated optical methods for measuring the electric field locally are critically discussed.

关键词： Impedance resolution phase

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Low motional Impedance distributed Lame mode resonators for high frequency timing applications

引用

Microsystems & Nanoengineering 2020年第1期6卷 848-858页

作者： Anosh Daruwalla Haoran Wen Chang-Shun Liu Farrokh Ayazi School of Electrical and Computer Engineering Georgia Institute of TechnologyAtlantaUSA

This paper presents a novel high-Q silicon distributed Lamémode resonator(DLR)for VHF timing reference applications.The DLR employs the nature of shear wave propagation to enable a cascade of small square Lamémodes in beam or frame configurations with increased transduction area.Combined with high efficiency nano-gap capacitive transduction,it enables low motional Impedances while scaling the frequency to VHF range.The DLR designs are robust against common process variations and demonstrate high manufacturability across different silicon substrates and process specifications.Fabricated DLRs in beam and frame configurations demonstrate high performance scalability with high Q-factors ranging from 50 to 250 k,motional Impedances90°C in the VHF range,and are fabricated using a wafer-level-packaged HARPSS process.Packaged devices show excellent robustness against temperature cycling,device thinning,and aging effects,which makes them a great candidate for stable high frequency references in size-sensitive and power-sensitive 5 G and other IoT applications.

关键词： resonator Impedance mode

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：