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The gas discharge visualization(GDV)order parameter model based on the principle of mastering both permanence and change
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作者 XIN Yu ZHANG Lei +3 位作者 ZHAO Qiancheng SHE Yurong SHE Zhensu SONG Shuna 《Digital Chinese Medicine》 CAS CSCD 2024年第3期231-240,共10页
Objective To investigate the human body’s complex system,and classify and characterize the human body’s health states with“a comprehensive integrated method from qualitative to quantitative”.Methods This paper int... Objective To investigate the human body’s complex system,and classify and characterize the human body’s health states with“a comprehensive integrated method from qualitative to quantitative”.Methods This paper introduces the concept of“order parameters”and proposes a method for establishing an order parameter model of gas discharge visualization(GDV)based on the principle of“mastering both permanence and change(MBPC)”.The method involved the fol-lowing three steps.First,average luminous intensity(I)and average area(S)of the GDV im-ages were calculated to construct the phase space,and the score of the health questionnaire was calculated as the health deviation index(H).Second,the k-means++clustering method was employed to identify subclasses with the same health characteristics based on the data samples,and to statistically determine the symptom-specific frequencies of the subclasses.Third,the distance(d)between each sample and the“ideal health state”,which determined in the phase space of each subclass,was calculated as an order parameter describing the health imbalance,and a linear mapping was established between the d and the H.Further,the health implications of GDV signals were explored by analyzing subclass symptom profiles.We also compare the mean square error(MSE)with classification methods based on age,gen-der,and body mass index(BMI)indices to verify that the phase space possesses the ability to portray the health status of the human body.Results This study preliminarily tested the reliability of the order parameter model on data samples provided by 20 participants.Based on the discovered linear law,the current model can use d calculated by measuring the GDV signal to predict H(R^(2)>0.77).Combined with the symptom profiles of the subclasses,we explain the classification basis of the phase space based on the pattern identification.Compared with common classification methods based on age,gender,BMI,etc.,the MSE of phase space-based classification was reduced by an order of magnitude.Conclusion In this study,the GDV order parameter model based on MBPC can identify sub-classes and characterize individual health levels,and explore the TCM health meanings of the GDV signals by using subjective-objective methods,which holds significance for establishing mathematical models from TCM diagnosis principles to interpret human body signals. 展开更多
关键词 Gas discharge visualization(GDV) Traditional Chinese medicine(TCM) order parameters Math-physical model Individualized health assessment
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Optimal Scheduling of PEV Charging/Discharging in Microgrids with Combined Objectives
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作者 Chong Cao Ming Cheng Bo Chen 《Smart Grid and Renewable Energy》 2016年第4期115-130,共16页
While renewable power generation and vehicle electrification are promising solutions to reduce greenhouse gas emissions, it faces great challenges to effectively integrate them in a power grid. The weather-dependent p... While renewable power generation and vehicle electrification are promising solutions to reduce greenhouse gas emissions, it faces great challenges to effectively integrate them in a power grid. The weather-dependent power generation of renewable energy sources, such as Photovoltaic (PV) arrays, could introduce significant intermittency to a power grid. Meanwhile, uncontrolled PEV charging may cause load surge in a power grid. This paper studies the optimization of PEV charging/discharging scheduling to reduce customer cost and improve grid performance. Optimization algorithms are developed for three cases: 1) minimize cost, 2) minimize power deviation from a pre-defined power profile, and 3) combine objective functions in 1) and 2). A Microgrid with PV arrays, bi-directional PEV charging stations, and a commercial building is used in this study. The bi-directional power from/to PEVs provides the opportunity of using PEVs to reduce the intermittency of PV power generation and the peak load of the Microgrid. Simulation has been performed for all three cases and the simulation results show that the presented optimization algorithms can meet defined objectives. 展开更多
关键词 PEV charging/discharging Scheduling MICROGRIDS PV Arrays OPTIMIZATION
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Surface charge characteristics in a three-electrode surface dielectric barrier discharge
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作者 Jingwen FAN Huijie YAN +3 位作者 Ting LI Yurong MAO Jiaqi LI Jian SONGKey 《Plasma Science and Technology》 SCIE EI CAS CSCD 2024年第11期127-137,共11页
The surface charge characteristics in a three-electrode surface dielectric barrier discharge(SDBD)are experimentally investigated based on the Pockels effect of an electro-optical crystal. The actuator is based on the... The surface charge characteristics in a three-electrode surface dielectric barrier discharge(SDBD)are experimentally investigated based on the Pockels effect of an electro-optical crystal. The actuator is based on the most commonly used SDBD structure for airflow control, with an exposed electrode supplied with sinusoidal AC high voltage, a grounded encapsulated electrode and an additional exposed electrode downstream supplied with DC voltage. The ionic wind velocity and thrust can be significantly improved by increasing DC voltage although the plasma discharge characteristics are virtually unaffected. It is found that the negative charges generated by the discharge of the three-electrode structure accumulate on the dielectric surface significantly further downstream in an AC period compared to the actuator with a two-electrode structure. The negative charges in the downstream region increase as the DC voltage increases.In addition, the DC voltage affects the time required for the positive charge filaments to decay.The positive DC voltage expands the ionic acceleration zone downstream to produce a greater EHD force. The amplitude of the DC voltage affects the electric field on the dielectric surface and is therefore a key factor in the formation of the EHD force. Further research on the surface charge characteristics of a three-electrode structure has been conducted using a pulse power to drive the discharge, and the same conclusions are drawn. This work demonstrates a link between surface charge characteristics and EHD performance of a three-electrode SDBD actuator. 展开更多
关键词 surface dielectric barrier discharge three-electrode structure electro-optical crystal surface charge
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Formation mechanism of bright and dark concentric-ring pattern in dielectric barrier discharge
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作者 李彩霞 冯建宇 +4 位作者 王舒畅 李骋 冉俊霞 潘宇扬 董丽芳 《Plasma Science and Technology》 SCIE EI CAS CSCD 2024年第8期50-57,共8页
In this work,a bright and dark concentric-ring pattern is reported in a dielectric barrier discharge for the first time.The spatiotemporal dynamics of the bright and dark concentric-ring pattern are investigated with ... In this work,a bright and dark concentric-ring pattern is reported in a dielectric barrier discharge for the first time.The spatiotemporal dynamics of the bright and dark concentric-ring pattern are investigated with an intensified charge-coupled device and photomultiplier tubes.The results indicate that the bright and dark concentric-ring pattern is composed of three concentric-ring sublattices.These are bright concentric-ring structures,dark concentric-ring structures and wider concentric-ring structures,respectively.The bright concentric-ring structures and dark concentricring structures are alternately distributed.The bright concentric-ring structures are located at the centre of the wider concentric-ring structures.The wider concentric-ring structures first form from the outer edge and gradually develop to the centre.The essence of all three concentric-ring structures is the individual discharge filaments.The optical emission spectra of different sublattices are acquired and analysed.It is found that the plasma parameters of the three concentricring sublattices are different.Finally,the formation mechanism of the bright and dark concentricring pattern is discussed. 展开更多
关键词 dielectric barrier discharge(DBD) concentric-ring pattern spatio-temporal dynamics optical emission spectroscopy wall charges
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Discharge mode and particle transport in radio frequency capacitively coupled Ar/O_(2) plasma discharges
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作者 Zhuo-Yao Gao Wan Dong +3 位作者 Chong-Biao Tian Xing-Zhao Jiang Zhong-Ling Dai Yuan-Hong Song 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第9期451-460,共10页
Simulations are conducted on capacitively coupled Ar/O_(2)mixed gas discharges employing a one-dimensional fluid coupled with an electron Monte Carlo(MC)model.The research explores the impact of different O_(2)ratio a... Simulations are conducted on capacitively coupled Ar/O_(2)mixed gas discharges employing a one-dimensional fluid coupled with an electron Monte Carlo(MC)model.The research explores the impact of different O_(2)ratio and pressures on the discharge characteristics of Ar/O_(2)plasma.At a fixed Ar/O_(2)gas ratio,with the increasing pressure,higher ion densities,as well as a slight increase in electron density in the bulk region can be observed.The discharge remains dominated by the drift-ambipolar(DA)mode,and the flux of O(3P)at the electrode increases with the increasing pressure due to higher background gas density,while the fluxes of O(1D)and Ardecrease due to the pronounced loss rate.With the increasing proportion of O_(2),a change in the dominant discharge mode from a mode to DA mode can be detected,and the O_(2)-associated charged particle densities are significantly increased.However,Ar+density shows a trend of increasing and then decreasing,while for neutral fluxes at the electrode,Arflux decreases,and O(3P)flux increases with the reduced Ar gas proportion,while trends in O(1D)flux show slight differences.The evolution of the densities of the charged particle and the neutral fluxes under different discharge parameters are discussed in detail using the ionization characteristics as well as the transport properties.Hopefully,more comprehensive understanding of Ar/O_(2)discharge characteristics in this work will provide a valuable reference for the industry. 展开更多
关键词 Ar/O_(2) mixed gas discharges electron dynamics transport of charged and neutral particles
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Ordered Charge Distribution in Superconductor Tl-Ba-Ca-Cu-O
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作者 LI Ping XIAO Shen xiu WANG Rong shun 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 1999年第3期271-280,共10页
The layered charges were calculated by means of constructing the complete structure of Tl Ba Ca Cu O superconductor. The weak link between Cu O and Ba O, or between Cu O and Tl O or Ba O or Tl O layers i... The layered charges were calculated by means of constructing the complete structure of Tl Ba Ca Cu O superconductor. The weak link between Cu O and Ba O, or between Cu O and Tl O or Ba O or Tl O layers is explained with the aid of the charge of limited layer unit calculated from the values of ions obtained, in addition to the possibility of forming charges fluctuation, which depends on the π coordination covalent bond on Cu O plane and O Tl O structure. The possible chemical tight bonding orbitals are in accordance with those of other superconductors obtained by quantum theoretical method, which occur at Cu 3d (x 2-y 2) and O 2p x,y . The valence band composed of Cu 3d and O 2p orbital energy levels is obviously an energy band of conduction. The ordered charge on layers is the main reason that raises T c of superconductors. The difference of electronic structure of ab plane and c axis leads to the anisotropy properties. 展开更多
关键词 SUPERCONDUCTOR ordered charge Completing structure Exchange and correlation potential Layer
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Experiment Study on the Ending Criteria of Charge and Discharge of Nickel-Hydride Battery 被引量:4
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作者 孙逢春 陈勇 +1 位作者 何洪文 张承宁 《Journal of Beijing Institute of Technology》 EI CAS 2002年第1期56-60,共5页
Charge and discharge characteristics of Ni/MH batteries are investigated with experiments. During battery’s working, the voltage, capacity, temperature and internal resistance were recorded, corresponding curves were... Charge and discharge characteristics of Ni/MH batteries are investigated with experiments. During battery’s working, the voltage, capacity, temperature and internal resistance were recorded, corresponding curves were depicted. Variations of the aforementioned four parameters are differently obvious. Ending criteria of charge and discharge of Ni/MH batteries are discussed on the basis of the curves. Voltage, capacity and temperature of a battery can be used as ending criteria during charge. When discharge takes place, voltage, capacity and internal resistance can be chosen as ending criteria. As a whole, capacity is more suitable for being used as ending criteria of charge and discharge than the other three parameters. At last, the capacity of a battery is recommended to be ending criteria of charge and discharge. The conclusions will provide references to different capacity Ni/MH batteries for electric vehicles. 展开更多
关键词 electric vehicles Ni/MH batteries charge and discharge characteristics charge and discharge criteria
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Ultrasonic Study on Charge Ordering in Nd0.5Ca0.5Mn1-xAlxO3(x=0,0.03)
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作者 刘毅 孔辉 +1 位作者 苏金瑞 朱长飞 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 北大核心 2006年第6期535-538,共4页
The ultrasonic, magnetic and transport properties of Nd0.5Ca0.5Mn1-xAlxO3 (x=0, 0.03) were studied from 15 to 300 K. The temperature dependencies of resistivity and magnetization show that Nd0.5Ca0.5MnO3 undergoes a... The ultrasonic, magnetic and transport properties of Nd0.5Ca0.5Mn1-xAlxO3 (x=0, 0.03) were studied from 15 to 300 K. The temperature dependencies of resistivity and magnetization show that Nd0.5Ca0.5MnO3 undergoes a charge ordering transition at TCO-257 K. An obvious softening of the longitudinal sound velocity above TCO and a dramatic stiffening below Too accompanied by an attenuation peak were observed. These features imply a strong electron phonom interaction via the Jahn-Teller effect iu the sample, Another broad attenuation peak was observed at around Tp-80 K. This anomaly is attributed to the phase separtion between the antiferromagnetic (AFM) and paramagnetic (PM) phases and gives a direct evidence for spin-phonon coupling in the compound. For the x=0.03 sample, both the minimum of sound velocity and attenuation peaks shift to a lower temperature. The results indicate that the charge ordering and CE-type AFM state in Nd0.5Ca0.5MnO3 are both partially suppressed by replacing Mn with A1. 展开更多
关键词 MANGANITE charge ordering Phase separation Ultrasonic velocity and attenuation
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Destruction of charge ordering phase in La_(0.4)Ca_(0.6)MnO_3 induced by low Cr doping 被引量:6
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作者 PENG Zhensheng YANG Gang +3 位作者 WANG Guiying TANG Yonggang GUO Huanyin MAO Qiang 《Rare Metals》 SCIE EI CAS CSCD 2011年第3期241-246,共6页
Polycrystalline samples of La0.4Cao.6Mn1-xCrxO3 (x = 0.00, 0.02, 0.04, 0.06) were prepared by the solid state reaction method. The influence of Cr3+ substitution for Mn3+ on the magnetic property and charge orderi... Polycrystalline samples of La0.4Cao.6Mn1-xCrxO3 (x = 0.00, 0.02, 0.04, 0.06) were prepared by the solid state reaction method. The influence of Cr3+ substitution for Mn3+ on the magnetic property and charge ordering phase of La0.4Ca0.6MnO3 was studied through the measurements of X-ray diffraction (XRD), magnetization-temperature (M-T) curves and electron spin resonance (ESR) spectra. The experimental results indicate that the mother's body of La0.4Ca0.6MnO3 has very complicated magnetic structure, exhibits charge ordering phase at 258 K, and shows long-range strongly correlated charge ordering-antiferromagnetism (CO-AFM) phase from 175 to 50 K. Spin glass state appears when the temperature decreases to about 41 K. When the Cr substitution amount is x = 0.06, the charge ordering phase of the mother's body is de-stroyed, because the Cr3+ substitution for Mn3+ destroys the spin order of CE-type antiferromagnetism, and thus leads to the melting of charge ordering. It is verified experimentally that the strong coupling between charge order and spin order exists in the charge order system of CE-type antiferromagnetism. 展开更多
关键词 perovskite manganite CHROMIUM DOPING charge ordering spin-glass state
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High-magnetic-field induced charge order in high-T_c cuprate superconductors 被引量:2
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作者 L X Zheng J Li T WU 《Chinese Physics B》 SCIE EI CAS CSCD 2019年第11期25-42,共18页
In the last few years, charge order and its entanglement with superconductivity are under hot debate in high-Tc community due to the new progress on charge order in high-Tc cuprate superconductors YBa2Cu3O6+x. Here, w... In the last few years, charge order and its entanglement with superconductivity are under hot debate in high-Tc community due to the new progress on charge order in high-Tc cuprate superconductors YBa2Cu3O6+x. Here, we will briefly introduce the experimental status of this field and mainly focus on the experimental progress of high-field nuclear magnetic resonance(NMR) study on charge order in YBa2Cu3O6+x. The pioneering high-field NMR work in YBa2Cu3O6+x sets a new stage for studying charge order which has become a ubiquitous phenomenon in high-Tc cuprate superconductors. 展开更多
关键词 chargE order CUPRATES NUCLEAR magnetic RESONANCE YBa2Cu3O6+x SUPERCONDUCTORS competing order
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Research on charge ordering and magnetic properties in La_(0.3)Ca_(0.7)Mn_(1-x)W_xO_3 system 被引量:2
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作者 PENG Zhensheng GUO Huanyin +1 位作者 YAN Guoqing MAO Qiang 《Rare Metals》 SCIE EI CAS CSCD 2007年第4期317-322,共6页
The perovskite manganite sample La0.3Ca0.7Mn1-xWxO3 (x = 0.08, 0.12) was prepared by the solid-state reaction method. The effect of W doping on the Mn site to La0.3Ca0.7MnO3 charge ordering phase and the changing pr... The perovskite manganite sample La0.3Ca0.7Mn1-xWxO3 (x = 0.08, 0.12) was prepared by the solid-state reaction method. The effect of W doping on the Mn site to La0.3Ca0.7MnO3 charge ordering phase and the changing process of magnetic properties were studied through the measurement of the M-T curve, M-H curves, and ESR curves of the sample. The results showed that when x = 0.08, the charge ordering (CO) phase exists in the system, the transition temperature Tco= 275 K, and the system exhibits PM when T 〉 275 K. The system transforms from spin-disordering paramagnetism to spin-ordering antiferromagnetism in the charge ordering state with the temperature decreasing from 275 K to 230 K. The long-range antiferromagnetism forms and AFM/CO states coexist between 230 K and 5 K. There is a little ferromagnetic component in the AFM/CO background in a low temperature range. When x = 0.12, the CO phase in the system has almost melted completely. There is a little remnant of the CO phase below 150 K. The system exhibits paramagnetism when T 〉 150 K and transforms from paramagnetism to ferromagnetism when T〈 150 K. 展开更多
关键词 condensed matter physics charge ordering MELTING solid-state reaction method magnetic properties
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A Comparative Study of Fractional Order Models on State of Charge Estimation for Lithium Ion Batteries 被引量:5
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作者 Jinpeng Tian Rui Xiong +1 位作者 Weixiang Shen Ju Wang 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2020年第4期98-112,共15页
State of charge(SOC)estimation for lithium ion batteries plays a critical role in battery management systems for electric vehicles.Battery fractional order models(FOMs)which come from frequency-domain modelling have p... State of charge(SOC)estimation for lithium ion batteries plays a critical role in battery management systems for electric vehicles.Battery fractional order models(FOMs)which come from frequency-domain modelling have provided a distinct insight into SOC estimation.In this article,we compare five state-of-the-art FOMs in terms of SOC estimation.To this end,firstly,characterisation tests on lithium ion batteries are conducted,and the experimental results are used to identify FOM parameters.Parameter identification results show that increasing the complexity of FOMs cannot always improve accuracy.The model R(RQ)W shows superior identification accuracy than the other four FOMs.Secondly,the SOC estimation based on a fractional order unscented Kalman filter is conducted to compare model accuracy and computational burden under different profiles,memory lengths,ambient temperatures,cells and voltage/current drifts.The evaluation results reveal that the SOC estimation accuracy does not necessarily positively correlate to the complexity of FOMs.Although more complex models can have better robustness against temperature variation,R(RQ),the simplest FOM,can overall provide satisfactory accuracy.Validation results on different cells demonstrate the generalisation ability of FOMs,and R(RQ)outperforms other models.Moreover,R(RQ)shows better robustness against truncation error and can maintain high accuracy even under the occurrence of current or voltage sensor drift. 展开更多
关键词 Electric vehicle Lithium ion battery Fractional order model State of charge
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Characteristics of charge and discharge of PMMA samples due to electron irradiation 被引量:1
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作者 封国宝 王芳 +1 位作者 胡天存 曹猛 《Chinese Physics B》 SCIE EI CAS CSCD 2015年第11期518-524,共7页
In this study, using a comprehensive numerical simulation of charge and discharge processes, we investigate the formation and evolution of negative charge and discharge characteristics of a grounded PMMA film irradiat... In this study, using a comprehensive numerical simulation of charge and discharge processes, we investigate the formation and evolution of negative charge and discharge characteristics of a grounded PMMA film irradiated by a non- focused electron beam. Electron scattering and transport processes in the sample are simulated with the Monte Carlo and the finite-different time-domain (FDTD) methods, respectively. The properties of charge and discharge processes are presented by the evolution of internal currents, charge quantity, surface potential, and discharge time. Internal charge accumulation in the sample may reach saturation by primary electron (PE) irradiation providing the charge duration is enough. Internal free electrons will run off to the ground in the form of leakage current due to charge diffusion and drift during the discharge process after irradiation, while trapped electrons remain. The negative surface potential determined by the charging quantity decreases to its saturation in the charge process, and then increases in the discharge process. A larger thickness of the PMMA film will result in greater charge amount and surface potential in charge saturation and in final discharge state, while the electron mobility of the material has little effects on the final discharge state. Moreover, discharge time is less for smaller thickness or larger electron mobility. The presented results can be helpful for estimating and weakening the charging of insulating samples especially under the intermittent electron beam irradiation in related surface analysis or measurement. 展开更多
关键词 charge and discharge PMMA numerical simulation electron irradiation
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Decay characters of charges on an insulator surface after different types of discharge 被引量:1
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作者 Cheng PAN Ju TANG +3 位作者 Dibo WANG Yi LUO Ran ZHUO Mingli FU 《Plasma Science and Technology》 SCIE EI CAS CSCD 2017年第7期93-101,共9页
In an insulating system including solid and gas dielectrics, discharge type has a strong impact on charge accumulation at the interface between two dielectrics, and hence charge decay. In order to clarify the influenc... In an insulating system including solid and gas dielectrics, discharge type has a strong impact on charge accumulation at the interface between two dielectrics, and hence charge decay. In order to clarify the influence, a surface charge measurement system was constructed, and three types of discharge, i.e. surface discharge, and low intensity and high intensity coronas, were introduced to cause surface charge accumulation. The decay behavior of surface charges after different types of discharge was obtained at various temperatures. It was found that total surface charges monotonically decreased with time, and the decay rate became larger as temperature increased. However, after a surface discharge or a high intensity corona, surface charge density in the local area appeared to fluctuate during the decay process. Compared with this, the fluctuation of surface charge density was not observed after a low intensity corona. The mechanisms of surface charge accumulation and decay were analysed. Moreover, a microscopic physical model involving charge production, accumulation, and decay was proposed so that the experimental results could be explained. 展开更多
关键词 surface discharge CORONA surface charge accumulation surface charge decay insulator
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3D Carbon Frameworks for Ultrafast Charge/Discharge Rate Supercapacitors with High Energy‑Power Density 被引量:3
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作者 Changyu Leng Zongbin Zhao +6 位作者 Yinzhou Song Lulu Sun Zhuangjun Fan Yongzhen Yang Xuguang Liu Xuzhen Wang Jieshan Qiu 《Nano-Micro Letters》 SCIE EI CAS CSCD 2021年第1期112-122,共11页
Carbon-based electric double layer capacitors(EDLCs)hold tremendous potentials due to their high-power performance and excellent cycle stability.However,the practical use of EDLCs is limited by the low energy density ... Carbon-based electric double layer capacitors(EDLCs)hold tremendous potentials due to their high-power performance and excellent cycle stability.However,the practical use of EDLCs is limited by the low energy density in aqueous electrolyte and sluggish diffusion kinetics in organic or/and ionic liquids electrolyte.Herein,3D carbon frameworks(3DCFs)constructed by interconnected nanocages(10-20 nm)with an ultrathin wall of ca.2 nm have been fabricated,which possess high specific surface area,hierarchical porosity and good conductive network.After deoxidization,the deoxidized 3DCF(3DCFDO)exhibits a record low IR drop of 0.064 V at 100 A g^−1 and ultrafast charge/discharge rate up to 10 V s^−1.The related device can be charged up to 77.4%of its maximum capacitance in 0.65 s at 100 A g^−1 in 6 M KOH.It has been found that the 3DCF-DO has a great affinity to EMIMBF4,resulting in a high specific capacitance of 174 F g^−1 at 1 A g^−1,and a high energy density of 34 Wh kg^−1 at an ultrahigh power density of 150 kW kg^−1 at 4 V after a fast charge in 1.11 s.This work provides a facile fabrication of novel 3D carbon frameworks for supercapacitors with ultrafast charge/discharge rate and high energy-power density. 展开更多
关键词 3D carbon frameworks NANOCAGES Ultrafast charge/discharge rate High energy-power density SUPERCAPACITORS
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A Repetitive Nanosecond Pulse Source for Generation of Large Volume Streamer Discharge 被引量:1
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作者 陶凤波 张乔根 +2 位作者 高博 王虎 李舟 《Plasma Science and Technology》 SCIE EI CAS CSCD 2008年第5期588-593,共6页
Using a unipolar pulse with the rise time and the pulse duration in the order of microsecond as the primary pulse, a nanosecond pulse with the repetitive frequency of several kilohertz is generated by a spark gap swit... Using a unipolar pulse with the rise time and the pulse duration in the order of microsecond as the primary pulse, a nanosecond pulse with the repetitive frequency of several kilohertz is generated by a spark gap switch. By varying both the inter-pulse duration and the pulse frequency, the voltage recovery rate of the spark gap switch is investigated at different working conditions such as the gas pressure, the gas composition as well as the bias voltage. The results reveal that either increase in gas pressure or addition of SF6 to the air can increase the voltage recovery rate. The effect of gas composition on the voltage recovery rate is discussed based on the transferring and distribution of the residual space charges. The repetitive nanosecond pulse source is also applied to the generation of large volume, and the discharge currents are measured to investigate the effect of pulse repetition rate on the large volume streamer discharge. 展开更多
关键词 spark gap switch voltage recovery residual charge streamer discharge
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Simulation Studies of Rib Structure Effect on Discharge Characteristics of Plasma Display Panel 被引量:1
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作者 丁可 邓斌 +2 位作者 单莉英 孙琦 顾昌鑫 《Plasma Science and Technology》 SCIE EI CAS CSCD 2007年第1期80-88,共9页
To investigate the effect of the rib structure on the discharge characteristics of the plasma display panel, the potential distribution, particles density distribution and ions incident angle distribution were examine... To investigate the effect of the rib structure on the discharge characteristics of the plasma display panel, the potential distribution, particles density distribution and ions incident angle distribution were examined by simulation of a two-dimensional particle-in-cell/Monte Carlo collision, with two kinds of rib structure: the stripe rib structure and the Waffle rib structure. The results showed that the distribution of electric potential at the corner of the discharge cell was almost the same for these two rib structures while in the centre there was a difference between these two rib structures. The striation phenomenon could be observed in both cases. The distribution of density also indicated that the striation phenomenon was accompanied by the firing of discharge, and the Waffle rib structure might reduce the density humps. In the cell with a stripe rib structure, the profiles of the surface charge density along the sustained dielectric layer presented a better fluctuating distribution than that in the cell with a Waffle rib structure. The spatial potential and particle density in the discharge bulk showed that the Waffle ribs could weaken the striation phenomenon, which could be explained by the decrease in the particle numbers in the discharge cell. The simulation results of the ion incident angle showed that most ions impacted the sustained dielectric layer in the normal stripe rib cell with an incident angle in the range of 6° to 19° while with the Waffle rib structure the incident angle of most ions was in the range of 4° to 19°. The Waffle rib structure did not affect the angle distribution of incident ions significantly. 展开更多
关键词 discharge characteristics surface charge ion angle distribution plasma display panel
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Collapse of charge ordering in Bi_(0.5)Sr_(0.5)MnO_3 by cation disorder: a magnetic and structural investigation 被引量:1
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作者 S. Savitha Pillai Rajasekhar Madugundo Santhosh. P. Nagappan Nair 《Journal of Rare Earths》 SCIE EI CAS CSCD 2008年第2期237-240,共4页
The structure, transport, and magnetic properties of LaxBi0.5.xSr0.5MnO3 (LBSMO) (x=0.1 and 0.4) were studied through X-ray diffraction, magnetization, and electron spin resonance (ESR) measurements. The structu... The structure, transport, and magnetic properties of LaxBi0.5.xSr0.5MnO3 (LBSMO) (x=0.1 and 0.4) were studied through X-ray diffraction, magnetization, and electron spin resonance (ESR) measurements. The structural analysis showed that the LBSMO crystallized in an orthorhombic perovskite structure with Pbnm space group for x=-0.1 and Imma space group for x=0.4 and the highly polarizable 6s^2 lone pair of Bi^3+ was the ttming factor for the structural variations. Magnetic studies revealed that the replacement of Bi ions by La ions resulted in the collapse high temperature charge ordering state of BSMO and it order Ferro Magnetically (FM) with Tc around 355 and 330 K for x=0.1 and 0.4, respectively. Both ESR, temperature and field dependant magnetization suggested that there was a coexistence of FM and the paramagnetic phases well below Tc and the FM and CO-AFM phases below 250 K of LBSMO. 展开更多
关键词 charge ordering (CO) colossal magneto resistance (CMR) rare earths
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The enhanced aerosol deposition by bipolar corona discharge arrays 被引量:1
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作者 Jiacheng LI Zhongzheng HUANG +1 位作者 Dawei LIU Kuanlei ZHENG 《Plasma Science and Technology》 SCIE EI CAS CSCD 2021年第6期83-88,共6页
The corona discharges provide an efficient way to induce precipitation or eliminate fog by increasing ion density in the open air.In this paper,one bipolar corona discharge array(positive and negative high voltage cou... The corona discharges provide an efficient way to induce precipitation or eliminate fog by increasing ion density in the open air.In this paper,one bipolar corona discharge array(positive and negative high voltage coupled simultaneously)which can generate high densities of positive and negative ions is developed.The comparison between bipolar corona discharge array and unipolar corona discharge array(positive or negative coupled only)indicates that bipolar corona discharge array can generate~3 times higher ion density than unipolar corona discharge array.More charged aerosols are produced through collisions between ions and aerosols.The collision rate between aerosols is increased substantially by the attractive forces between positively and negatively charged aerosols.The deposition of aerosols induced by bipolar discharges is 25.7%higher than that of unipolar discharges at the humidity super-saturation condition.Therefore,the bipolar corona discharge system is a new option for the large scale ion sources used for artificial weather modification. 展开更多
关键词 corona discharges charged aerosols bipolar discharges
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Structural characteristics of spherical Ni(OH)_2 and its charge/discharge process mechanism 被引量:2
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作者 彭美勋 沈湘黔 +1 位作者 王零森 危亚辉 《Journal of Central South University of Technology》 2005年第1期5-8,共4页
Spherical Ni(OH)2 particles were prepared by an aqueous solution precipitation route. The structure of spherical Ni(OH)2 was investigated by scanning electron microscopy and transmission electron microscopy and co... Spherical Ni(OH)2 particles were prepared by an aqueous solution precipitation route. The structure of spherical Ni(OH)2 was investigated by scanning electron microscopy and transmission electron microscopy and compared with that of traditional Ni(OH)2. The results show that the spherical nickel hydroxide consists of (Ni(OH)2) spheres with a reticulate structure of platelet-like, which is almost arranged radially and the crystalline grains intervene and connect with each other to form a three-dimensional net. The spherical Ni(OH)2 particle is full of pores, crannies between cleave planes. It is supposed that this structure is beneficial to the structural stability for the spherical particles during the charge/discharge processes and can improve the cycle life of the electrode; the pores and the crannies in spherical particles can shorten the proton diffusion distance and speed its velocity, which may result in that the local polarization is lowered. The electrochemical performances of the spherical Ni(OH)2 are improved by enhancing the conducting properties of the crystalline lattice due to its quick proton diffusion. 展开更多
关键词 structure CRYSTALLINITY spherical Ni(OH)_2 proton diffusion charge/discharge process
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