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High Voltage 2024年第1期9卷 150-162页

作者： ruoyu han Houda Zhu Qing Chen Hongbin Li Yue Tong Linshan han Yang Jiao School of Electrical and Electronic Engineering Huazhong University of Science and TechnologyWuhanChina China Electric Power Research Institute WuhanChina School of Artificial Intelligence and Automation Huazhong University of Science and TechnologyWuhanChina

As voltage measuring devices are widely used in the high voltage power system with a primary-secondary-fusion structure,electronic voltage transformers are directly connected to the primary conductor and would face much more serious electromagnetic environments than general secondary *** a result,they would still experience failures even when general protection measures are adopted to suppress overvoltages'*** address this issue,an innovative method is proposed after analyses are conducted on the resonance between a transformer and an *** this method,an air-cored coil is installed in a transformer to artificially shift its natural frequency and to dodge the high-frequency dominant component of a transient overvoltage,avoiding the aforementioned resonance and suppressing the secondary *** addition,simulations and laboratory tests are conducted to prove this method's validity.

关键词： transient resonance mentioned

Observation and verification of surface electrical explosion driven by radial-distributed pulsed current in laboratory lightning strike test

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High Voltage 2024年第1期9卷 137-149页

作者： ruoyu han Yuchen Cao Yakun Liu Xi Chen Ting Li Chen Li Pengfei Li State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijingChina School of Mechatronical Engineering Beijing Institute of TechnologyBeijingChina Department of Electrical Engineering Shanghai Jiaotong UniversityShanghaiChina Beijing Institute of Astronautical System Engineering BeijingChina Aerospace Research Institute of Materials and Processing Technology BeijingChina

The laboratory lightning test is essential for assessing the effectiveness of lightning strike protection(LSP).Particularly,direct lightning strike damage can be performed with pulsed current injection into the *** paper focuses on the dynamic process of arc plasma and shock wave behaviour in the vicinity of the‘strike’point.A rod-plate discharge load is built for testing aluminium and coated plate under 40-kA-level pulsed *** visualisation of the luminous discharge plasma and its flow field via high-speed photography(from different angles)is meticulously designed and implemented,synchronised with electro-physical *** results indicate some new mechanisms for lightning strike damage,apart from the impulse heat loading from the thermal *** transient current injection through the arc root concentrates on a thin skin layer(skin-depth effect),with the radial-attenuated current density,driving asynchronously electrical explosions on the plate *** inhomogeneous Joule heating of the plate leads to outwardly propagating phase transition and shock wave along the conductive *** addition,the electro-thermal instability is observed and regarded as the seed of irregular erosion *** information reveals two different plasma states of main discharge arc channel and adjacent surface electrical *** correspondence of the physical mechanism of electrical explosion and optical radiation is *** images for different regions depict erosion characteristics and summarise influencing factors,further confirming the mechanism *** research clarifies the role of skin-depth effect in transaction arc erosion for electrode,complements the electrical explosion theory with unevenly distributed current and helps optimise strategies of LSP.

关键词： electrical lightning radial

基于弹丸旋转规律的弹道终点辨识和引信全弹道安全控制方法

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兵工学报 2024年第9期45卷 3105-3113页

作者：史博陈曦李鹏斐韩若愚秦泗超贺中正孙颢洋北京理工大学机电学院北京100081

弹丸在飞行时所处的复杂环境可能引起弹药在待发状态下意外作用。基于6自由度刚体弹道方程组,运用4阶龙格-库塔算法对运动方程组进行数值计算,得到弹丸旋转速度随时间的衰减规律。采用某型榴弹开展炮射试验并回收试验数据,对弹丸旋转周... 详细信息

弹丸在飞行时所处的复杂环境可能引起弹药在待发状态下意外作用。基于6自由度刚体弹道方程组,运用4阶龙格-库塔算法对运动方程组进行数值计算,得到弹丸旋转速度随时间的衰减规律。采用某型榴弹开展炮射试验并回收试验数据,对弹丸旋转周期2阶导数的过零特征点进行验证。针对发射装药量和射角两个发射条件对特征点的影响规律进行研究,提出基于旋转特征点的弹道终点时刻辨识方法,设计基于磁场传感器的弹道终点实时辨识系统,并开展靶场炮射试验进行验证。研究结果表明,弹载弹道终点辨识系统和弹道跟踪雷达获取的弹道终点时刻相对误差小于5%,验证了所提弹道终点辨识方法的正确性。在此基础上,进一步提出适用于一种旋转稳定弹药的机械-电子双模全弹道安全控制方法,在利用发射后坐过载和旋转离心力两道环境信息的基础上,采用终点辨识作为第三道环境信息,实现引信全弹道安全控制。新提出的基于弹丸旋转规律的弹道终点辨识及引信安全控制方法,为提高旋转稳定弹药全弹道安全性提供了新的思路。

关键词：旋转稳定弹药引信全弹道安全控制旋转周期终点辨识 2阶导数

Experiments on plasma dynamics of electrical wire explosion in air

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High Voltage 2022年第1期7卷 117-136页

作者： ruoyu han Chen Li Wei Yuan Jiting Ouyang Jiawei Wu Yanan Wang Weidong Ding Yongmin Zhang School of Physics Beijing Institute of TechnologyBeijingChina Global Energy Interconnection Development and Cooperation Organization BeijingChina State Key Laboratory of Electrical Insulation and Power Equipment Xi'an Jiaotong UniversityXi'anChina

Besides a typical high‐density plasma source,electrical explosion of conductors is also indispensable in switches,nanomaterial synthesis,shock‐wave sources,*** this paper,an experimental study regarding plasma dynamics of electrical wire explosions(μs‐timescale)is presented,with spatiotemporal resolved *** Cu/Ni wire and Cu‐Ni alloy wire were used and *** alloy wire usually has a higher resistivity,resulting in a higher initial energy deposition(heating)*** inverse transformation indicated that the plasma radiation focussed on the outer region of the discharge channel for the alloy *** addition,the metallic vapour determined by the material properties had a considerable influence on the plasma process and resulting *** particular,both transverse and axial‐layered structures were observed in alloy wire *** addition,for the first time,the expanding arc‐like plasma of explosion products was understood and examined from aspects of material properties and energy *** later stage of wire explosion resembled the state of regular metal vapour arcs under 1 MPa ***,the core factor for the fast energy deposition stage of wire explosion was *** between pre‐exposition circuit parameters and post‐explosion dynamic effects were found,which is significant for practical applications.

关键词： alloy vapour electrical

Dynamics of plasma bullets by nanosecond pulsed micro-hollow cathode discharge within air

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Plasma Science and Technology 2021年第8期23卷 82-88页

作者： Peizhen LI Zhengchao DUAN Tianliang ZhanG Feng HE ruoyu han Jiting OUYANG School of Physics Beijing Institute of TechnologyBeijing 100081People's Republic of China

In this paper,the air plasma jet produced by micro-hollow cathode discharge(MHCD)is *** discharge is powered by a positive nanosecond pulse high voltage *** waveforms of the discharge,the images of the jet,the evolution of the plasma bullet and the reactive species are obtained to analyze the characteristics of the MHCD plasma *** is found that the length of the plasma jet is almost proportional to the air flow rate of 2–6 *** plasma bullets appear one after another during a single period of the voltage waveform,and both of the two plasma bullets are formed during the positive pulse voltage *** propagation velocity of the two plasma bullets is on the order of several hundred m/s,which is approximate to that of the air *** results indicate that the gas flow has an important influence on the formation of this MHCD plasma jet.

关键词： air plasma jet plasma bullets micro-hollow cathode discharge nanosecond pulse

Discharge and post-explosion behaviors of electrical explosion of conductors from a single wire to planar wire array

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Plasma Science and Technology 2022年第1期24卷 151-164页

作者： Chen LI ruoyu han Yi LIU Jinlin ZHAO Yanan WANG Feng HE Jiting OUYANG Research Center for Electrostatics and Applications Beijing Institute of TechnologyBeijing 100081People’s Republic of China State Key Laboratory of Advanced Electromagnetic Engineering and Technology Huazhong University of Science and TechnologyWuhan 430074People’s Republic of China State Key Laboratory of Electrical Insulation and Power Equipment Xi'an Jiaotong UniversityXi'an 710049People’s Republic of China

This work deals with an experimental study of a Cu planar wire array(PWA)in air and water under the stored energy 300-1200 J.A single Cu wire is adopted as a controlled *** configurations of PWA and a wire with the same mass(cross-section area)but the different specific surface areas(15-223 cm^(2)g^(-1))are *** transient process is analyzed using high-speed photography in combination with the results of optical emission and *** characteristics revealed that PWA always has a higher electric power peak,early but higher voltage peak,as well as faster vaporization and ionization process than the single-wire *** to three times stronger optical emission could be obtained when replacing the single-wire with PWA,indicating a higher energy-density state is ***,in both air and water,single-wire load tends to develop a transverse stratified structure,while PWA is dominated by the uneven energy deposition among ***,the synchronism and uniformity of the PWA explosion are discussed.

关键词： electrical explosion wire array metal plasma plasma radiation shock wave

Comparison of double layer in argon helicon plasma and magnetized DC discharge plasma

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Plasma Science and Technology 2022年第3期24卷 114-122页

作者： Yueqing WANG Ruilin CUI ruoyu han Feng HE Tianliang ZhanG Jinsong MIAO Jiting OUYANG School of Physics Beijing Institute of TechnologyBeijing 100081People's Republic of China

We present in this paper the comparison of an electric double layer(DL)in argon helicon plasma and magnetized direct current(DC)discharge *** in high-density argon helicon plasma of 13.56 MHz RF discharge was investigated experimentally by a floating electrostatic probe and local optical emission spectroscopy(LOES).The DL characteristics at different operating parameters,including RF power(300-1500 W),tube diameter(8-60 mm),and external magnetic field(0-300 G),were *** comparison,DL in magnetized plasma channel of a DC discharge under different conditions was also measured *** results show that in both cases,DL appears in a divergent magnetic field where the magnetic field gradient is the largest and when the plasma density is sufficiently *** strength(or potential drop of DL)increases with the magnetic field in two different *** is suggested that the electric DL should be a common phenomenon in dense plasma under a gradient external magnetic *** in magnetized plasmas can be controlled properly by magnetic field structure and discharge mode(hence the plasma density).

关键词： helicon plasma magnetized plasma double layer diverging magnetic field electrostatic probe OES

Application of an atmospheric pressure plasma jet in a rat model of ischaemic stroke:Design,optimisation,and characteristics

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High Voltage 2023年第2期8卷 315-325页

作者： Ye Chen Bingyan Yang Yuqing Liu Lixin Xu Zhongfang Shi Yixiao Liu ruoyu han Fang Yuan Jiting Ouyang Xu Yan Kostya(Ken)Ostrikov Department of Pathophysiology Beijing Neurosurgical Institute/Beijing Tiantan HospitalCapital Medical UniversityBeijingChina School of Basic Medical Sciences Capital Medical UniversityBeijingChina School of Physics Beijing Institute of TechnologyBeijingChina School of Chemistry and Physics and Centre for Biomedical Technologies Queensland University of TechnologyBrisbaneQueenslandAustralia

Recent studies have shown the in vitro neuro-protective functions of atmospheric pressure plasma(APP)against multiple pathological injuries during ischaemic stroke(IS).However,whether APP treatment exerts a therapeutic effect on a rat IS model remains ***,on the basis of needle-to-ring dielectric barrier discharge,an atmospheric pressure plasma jet(APPJ)was designed,with the Helium as the working gas which was driven by a sinusoidal ***,the treatment conditions were optimised for IS rat model treatment and the characteristics of this APPJ were further ***,the rat IS model was established through 90 min middle cerebral artery occlusion(MCAO),and plasma was intermittently inhaled by rats via the nasal cavity for a 2 min period at 60 min of MCAO *** therapeutic effects of this plasma jet device were then evaluated using biomedical *** to our results,intermittent APP inhalation in the MCAO rats increased the serum NO content,improved the neurological function,enhanced regional cerebral blood flow,lowered brain infarction,and reduced the cell apoptosis in brain tissues of MCAO ***,our data provides a novel potential strategy for IS treatment by using atmospheric-pressure plasma inhalation.

关键词： needle cerebral MCAO treatment

斜拉桥非线性索力优化的影响矩阵构建方法研究

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桥梁建设 2023年第S2期53卷 97-103页

作者：韩若愚苑仁安中铁大桥勘测设计院集团有限公司湖北武汉430056

为研究更适用于非线性计算的影响矩阵构建方法,以一座主跨280 m和一座主跨1176 m的两塔三跨斜拉桥为背景,考虑几何非线性的影响,分别采用“索力控制法”和“索长控制法”2种影响矩阵构建方法进行斜拉索索力优化,对比2种影响矩阵法求解... 详细信息

为研究更适用于非线性计算的影响矩阵构建方法,以一座主跨280 m和一座主跨1176 m的两塔三跨斜拉桥为背景,考虑几何非线性的影响,分别采用“索力控制法”和“索长控制法”2种影响矩阵构建方法进行斜拉索索力优化,对比2种影响矩阵法求解结构响应和反算索力增量的计算精度,并研究2种影响矩阵法的计算效率和适用性。结果表明:斜拉桥待调目标与基准状态的差异越大,非线性效应越显著,影响矩阵线性叠加计算值与非线性有限元计算值之间的相对误差越大;对于主梁位移计算,随着斜拉桥跨度的增加,“索力控制法”始终保持很高精度,“索长控制法”精度逐渐降低,而对于塔底弯矩计算,2种方法的计算误差均随着目标增量的增大而增大;对于超大跨度斜拉桥,“索力控制法”的主调因素为目标索力,对目标状态的控制效果更优,“索长控制法”存在索力的相互影响,对非线性的适用性相对较差;实际运用中,应根据工程实际需要,结合有限元软件的计算功能以及优化算法,综合选择影响矩阵的构建方法。

关键词：斜拉桥索力优化影响矩阵几何非线性索力控制法索长控制法有限元法

Early-stage latent thermal failure of single-crystal Ni-rich layered cathode

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Journal of Energy Chemistry 2024年第9期96卷 578-587页

作者： Xiao han ruoyu Xu Yan Li Yang Ding Manchen Zhang Bo Wang Xiaoxing Ke Manling Sui Pengfei Yan Beijing Key Laboratory of Microstructure and Property of Solids Faculty of Materials and ManufacturingBeijing University of TechnologyBeijing 100124China Watt Laboratory Central Research InstituteHuawei Technologies Co.LTDShenzhen 518129GuangdongChina

High nickel content worsens the thermal stability of layered cathodes for lithium-ion batteries,raising safety concerns for their *** understanding the thermal failure process can offer valuable guidance for material optimization on thermal stability and new opportunities in monitoring battery thermal runaway(TR).Herein,this work comprehensively investigates the thermal failure process of a single-crystal nickel-rich layered cathode and finds that the latent thermal failure starts at∼120℃far below the TR temperature(225℃).During this stage of heat accumulation,sequential structure transition is revealed by atomic resolution electron microscopy,which follows the layered→cation mixing layered→LiMn_(2)O_(4)-type spinel→disordered spinel→rock *** progression occurs as a result of the continuous migration and densification of transition metal *** transition generates gaseous oxygen,initially confined within the isolated closed pores,thereby not showing any thermal failure phenomena at the *** temperature leads to pore growth and coalescence,and eventually to the formation of open pores,causing oxygen gas release and weight loss,which are the typical TR *** highlight that latent thermal instability occurs before the macro-level TR,suggesting that suppressing phase transitions caused by early thermal instability is a crucial direction for material *** findings can also be used for early warning of battery thermal runaway.

关键词： Thermal runaway Nickel-rich layered cathode Transmission electron microscopy Lithium-ion battery Phase transition