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High Voltage 2023年第5期8卷 1020-1029页

作者： Junyu Wei Dongxin He Teng Gao Lin Zhu Haochen Wang Qingquan Li Gilbert Teyssedre Shandong Provincial Key Laboratory of UHV Transmission Technology and Equipment School of Electrical Engineering Shandong UniversityJinanChina School of Materials Science and Engineering Shandong UniversityJinanChina UPS INPTCNRSLAPLACE(Laboratoire Plasma et Conversion d’Energie)University of ToulouseToulouseFrance

Silicone elastomers are widely used to encapsulate power electronic devices.However,such devices may be subjected to square‐wave pulsed voltages with a high rate of change,which can create significant challenges for encapsulation insulation.In this article,the molecular vibration of silicon elastomer at the edge of pulsed electric field is studied.Firstly,the relationship between the intensity of molecular vibration and the parameters of pulsed electric field is explored.The experimental results show that the amplitude of the vibrations decreases as the pulse‐edge time increases,and it increases linearly as the pulseedge slope increases.Furthermore,the amplitude of the vibrations is proportional to the square of the amplitude of the pulsed electric field,and it increases as the space charge density increases.Then,the force analysis of charged molecule at the pulse edges is calculated,and the theoretical change law of molecular vibration intensity with pulse edge slope is deduced.Comparing the theoretical results with the experimental results,it is found that they are highly consistent.Finally,electrically induced mechanical stress caused by molecular vibration was shown to be an important factor in insulation failure.

关键词： pulsed insulation vibrations

Realisation of the reconfigurable pulsed high magnetic field facility and its scientific application at Wuhan National pulsed High Magnetic Field Centre

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High Voltage 2023年第5期8卷 898-906页

作者： Jianfeng Xie Shaozhe Zhang Jiangtao Shi Junfeng Wang Liang Li Xiaotao Han Wuhan National High Magnetic Field Center Huazhong University of Science and TechnologyWuhanChina State Key Laboratory of Advanced Electromagnetic Engineering and Technology Huazhong University of Science and TechnologyWuhanChina

To generate arbitrary shape magnetic field waveforms for advanced scientific research,a reconfigurable pulsed high magnetic field facility(PHMFF)was developed at Wuhan National pulsed High Magnetic Field Centre(WHMFC).First,the basic elements of PHMFF are introduced,and a ternary physical model composed of energy storage unit,magnet,transmission circuits and other auxiliary units is summarised to describe various magnetic field systems.Second,in order to realise the reconfiguration of magnetic field systems based on detailed elements,the control system with the ability of dynamic construction and control sequence reconfiguration is designed.On this basis,the PHMFF has been realised and various magnetic field systems are constructed to produce arbitrary shape magnetic field waveforms,such as half‐sine,ultra‐high,flat‐top and repetitive field pulses,which not only enhances the capability and efficiency of PHMFF,but also makes more scientific research possible in pulsed magnetic fields.So far,a peak magnetic field of 94.8 T,a flat‐top magnetic field of 64 T/10 ms and a repetitive magnetic field waveform of 20 T/60 Hz have been achieved,and some experiments and studies on the physical properties of materials have been carried out at WHMFC.

关键词： magnetic field pulsed

Ultrasound-guided in vivo porcine liver ablation with nanosecond pulsed electric fields

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Hepatobiliary & Pancreatic Diseases International 2022年第5期21卷 503-507页

作者： Jun-Jie Huang Rong-Wei Ma Da-Zhi Li Sheng-Yong Yin Zhen Liu Lin Zhou Ke-Ping Yan Shu-Sen Zheng Department of Hepatobiliary and Pancreatic Surgery The First Affiliated HospitalZhejiang University School of MedicineHangzhou 310003China NHC Key Laboratory of Combined Multi-organ Transplantation The First Affiliated HospitalZhejiang University School of MedicineHangzhou 310003China Institute of Industrial Ecology and Environment College of Chemical and Biological EngineeringZhejiang UniversityHangzhou 310028China

To the Editor:In recent decades,local ablative therapies have evolved considerably and played an increasingly important role in the treatment of inoperable tumors.Conventional modalities are mainly based on thermal ablation to destroy targeted lesions,such as radiofrequency ablation[1].The clinical application of pulsed electric fields[2]is emerging as an innovative and promising technique for tumor ablation,which does not depend on heat energy and preserves surrounding tissues adjacent to tumors[3].Highvoltage ultrashort electric pulses compromise the integrity of the plasma membrane and destroy intracellular homeostasis.Nanosecond pulsed electric fields(nsPEFs),with a strength of several tens of kV/cm and a nanosecond duration,have attracted much attention and been extensively studied in cancer ablation[4,5].

关键词： homeostasis ablation pulsed

Dynamic response of pulsed laser-irradiated space debris

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Optoelectronics Letters 2023年第5期19卷 316-320页

作者： LIANG Xiaobo FENG Tao QU Junli SHI Mingdong TANG Hailiang ZHU Chunyan Xi’an Modern Control Technology Research Institute Xi'an 710065China

High-velocity small-sized space debris with a diameter of 1—10 cm can cause huge damage to orbiting satellites and spacecraft.In recent years,the technology of actively removing small-sized space debris by high-energy pulsed laser irradiation has attracted widespread attention from scholars around the world,who strive for giving the maximum protection to the safety of the low-earth orbit environment.This paper focuses on exploring the dynamic behavior of centimeter-sized space debris under space-based pulsed laser irradiation.For this purpose,a fluid-structure-thermal-plasma multiphysics coupling model is built for space debris,and the effect law of plasma plumes produced by space debris after laser irradiation at different time is drawn.The simulation and measurement results are compared for analysis,verifying the validity and reliability of the proposed method and the built simulation model.The findings of this study are expected to provide an important theoretical reference and guidance for the research on the application of pulsed lasers to the active removal of centimeter-sized space debris.

关键词： debris pulsed removing

pulsed radiofrequency inhibits expression of P2X3 receptors and alleviates neuropathic pain induced by chronic constriction injury in rats

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Chinese Medical Journal 2019年第14期132卷 1706-1712页

作者： Miao Fu Lan Meng Hao Ren Fang Luo Department of Anesthesiology Key Laboratory of Carcinogenesis and Translational Research(Ministry of Education)Peking University Cancer Hospital and InstituteBeijing 100142China Department of Pain Management Beijing Tiantan HospitalCapital Medical UniversityBeijing 100050China Department of Anesthesiology and Pain Management Beijing Tiantan HospitalCapital Medical UniversityBeijing 100050China

Background:pulsed radiofrequency (PRF) is a minimally invasive interventional technique that provides a novel and effective treatment strategy for neuropathic pain (NP).PRF is advantageous because it does not damage nerves and avoids sensory loss after treatment.At present,animal studies have demonstrated that PRF is safe and effective for relieving the NP associated with sciatic nerve damage in rats with chronic constriction injury (CCI).However,the mechanism through which this effect occurs is unknown.An increasing body of evidence shows that the expression of the P2X ligand-gated ion channel 3 (P2X3) receptor is closely related to NP;this study was to investigate whether the expression of this receptor is involved in NP relief due to PRF.Methods:A total of 36 healthy adult male Sprague-Dawley (SD) rats were randomly divided into three groups:Sham group,CCI group,and PRF group.The right sciatic nerve was ligated in CCI group and PRF group to establish a CCI model;the right sciatic nerve was separated but not ligated in Sham group.On day 14 after the operation,PRF was administered to the ligated sciatic nerve in PRF group (42℃,45 V,2 min).A non-live electrode was placed at the exposed sciatic nerve for the rats in Sham and CCI groups.The hindpaw withdrawal threshold (HWT) and thermal withdrawal latency (TWL) were measured at the right hindpaw at different time points before and after PRF or sham therapy.On day 28 after treatment,the dorsal root ganglion (DRG) and spinal dorsal horn of the right L4-6 were harvested from each group to determine the mRNA and protein levels of the P2X3 receptor.Results:On day 28 after PRF treatment,the HWT (8.33 ± 0.67 g vs.3.62 ± 0.48 g) and TWL (25.42 ± 1.90 s vs.15.10 ± 1.71 s) were significantly higher in PRF group as compared to CCI group (P < 0.05).The mRNA expression of the P2X3 receptor in the DRG in PRF group was 23.7% lower than that in CCI group (P < 0.05),in the spinal dorsal horns in PRF group was 22.7% lower than that in CCI group (P < 0.05).The protein expression of t

关键词： pulsed radiofrequency P2X3 receptor Neuropathic pain Chronic constriction injury

pulsed radiofrequency alleviated neuropathic pain by down-regulating the expression of substance P in chronic constriction injury rat model

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Chinese Medical Journal 2020年第2期133卷 190-197页

作者： Jing-Ai Wang Shao-Ning Niu Fang Luo Department of Anesthesiology Plastic Surgery HospitalChinese Academy of Medical ScienceBeijing 100144China Department of Anesthesiology Beijing Ditan HospitalCapital Medical UniversityBeijing 100015China Department of Pain Management Beijing Tiantan HospitalCapital Medical UniversityBeijing 100050China

Background:pulsed radiofrequency(PRF),as a non-invasive treatment of neuropathic pain(NP),has been widely administered clinically.Previous studies have shown that PRF has the potential to improve hyperalgesia in animal models of NP.However,there have been few reports to clarify whether the mechanism of PRF treatment of NP involves intervention in the expression of substance P(SP).Therefore,this study administered PRF treatment to chronic constriction injury(CCI)model rats and observed the sciatic nerve mechanical pain threshold and SP expression in the spinal cord to explore the mechanism of PRF treatment.Methods:A total of 96 Sprague-Dawley rats were randomly divided into the sham-surgery-sham-treatment group(S-S group),the sham-surgery-PRF group(S-P group),the CCI-sham-treatment group(C-S group),and the CCI-PRF group(C-P group).The C-S group and the C-P group underwent sciatic nerve CCI,while the other groups received a sham operation.At 14 days after the operation,the C-P group and the S-P group were treated with PRF for 300 s.We recorded the hindpaw withdrawal threshold(HWT)and the thermal withdrawal latency(TWL)of rats in the various groups at baseline,before treatment(0 days),and at 1,7,14,and 28 days after treatment.L4 to L6 spinal cord tissues were taken before treatment(0 days)and 1,7,14,and 28 days after treatment.The transcription and translation of SP were measured by quantitative polymerase chain reaction and Western blotting,respectively.Results:The HWT and the TWL in the C-P group 28 days after PRF treatment were significantly higher than those in the C-S group(95%confidence interval[CI]:5.84–19.50,P<0.01;95%CI:2.58–8.69,P=0.01).The expression of SP in the C-P group 28 days after PRF treatment was significantly lower than that in the C-S group(95%CI:1.17–2.48,P<0.01).Conclusions:PRF may alleviate CCI-induced NP by down-regulating the expression of SP in the spinal cord of CCI model rats.

关键词： pulsed radiofrequency Chronic constriction injury Sciatic nerve Substance P

Effect of low intensity pulsed ultrasound on expression of TIMP-2 in serum and expression of mmp-13 in articular cartilage of rabbits with knee osteoarthritis

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Asian Pacific Journal of Tropical Medicine 2015年第12期8卷 1014-1019页

作者： Jing-Bo Ji Xue-Fu Li Lei Liu Guang-Zhong Wang Xin-Feng Yan Department of Bone and Joint Affiliated Qianfoshan Hospital of Shandong University Department of Orthopedics.Liaocheng No.3 Hospital

Objective:To study the effect of low intensity pulsed ultrasound(LIPUS) on the expression of tissue inhibitor of metalloproteinase-2(TIMP-2) in the serum and expression of matrix metallopeptidase 13(MMP-13) in the articular cartilage cells of rabbits with knee osteoarthritis(OA).Methods:Inner patellar ligament defect method was used to establish the model of knee OA.Four weeks after the modeling,the arterial blood was drawn from the ear of each rabbit,while ELISA was employed to detect the expression of TIMP-2 in the serum.The chondrocytes were separated from animals in each group and then cultured in vitro.All rabbits were divided into control group,OA model group and OA + LIPUS group.Cells in the control and OA groups were not treated,while cells in the OA+ LIPUS group were treated with LIPUS(40 mW/cnr.1 time/day).Cells were collected 7 d later and the RNA and total protein were extracted respectively.Real-time PCR and Western blotting were employed to analyze the expression of MMP-13 in chondrocytes at the mRNA and protein level,respectively.Results:The success rate of establishment of OA model was 83%.The results of ELISA showed that the content of TIMP-2 in the serum of animals with OA was 22.3%,lower than the one in the control group(P<0.05).Compared with the normal control group,the expression of TIMP-2in the OA model group was significantly increased,while the expression of MMP-13 was significantly increased(P<0.05).After the stimulation of LIPUS,the expression of TIMP-2 and MMP-13 was close to the one in the normal control group.Conclusions:The inner patellar ligament defect method is a mature method to establish the rabbit OA model,with high success rate.The expression of serum TIMP-2 in the OA model group is significantly decreased.LIPUS can up-regulate TIMP-2 and down-regulate MMP-13.

关键词： Low intensity pulsed ultrasound Osteoarthritis TIM

Investigation on pulsed discharge mode in SF6-C2H6 mixtures

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Plasma Science and Technology 2020年第3期22卷 107-114页

作者：杨楠楠李国富赵永利张家良温小琼 State Key Laboratory for Material Modification Dalian University of TechnologyDalian 116024People’s Republic of China State Key Laboratory of Chemical Lasers Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023People’s Republic of China

The non-chain chemical HF(DF)laser is one of the most powerful electrically-driven lasers operating in mid-infrared,in which SF6-C2H6 mixtures are often used as lasering media.Due to the electronegativity of SF6,the discharge in SF6-C2H6 presents a complicated discharge mode.To achieve reproducible pulsed laser output,pulsed discharge in SF6-C2H6 mixtures is investigated for discharge mode using plane electrodes assisted by array pre-ionization spark pins in cathode surface.Firstly,two modes can be distinguished.One mode is called the selfsustained volume discharge(SSVD),which is characterized by spatial uniformity in the discharge gap and pulse to pulse repeatability.On the contrary,another mode includes random arc passages in the discharge gap and therefore cannot conduct lasering.By varying discharge conditions(gap voltage,gas pressure,etc)two discharge modes are observed.Secondly,the holding scope of the SSVD mode is analyzed for the optimal mixture ratio of 20:1,and the boundary tend of the holding scope of SSVD indicates there exists maximum gas pressure and maximum charging voltage for SSVD.Finally,the peak current of SSVD relates positively to charging voltage,while negatively to gas pressure,from which it is drawn that synchronous electron avalanches initiated by the sliding array overlap spatially into SSVD and thus SSVD is essentially an α ionization avalanche.

关键词： pulsed chemical HF laser SF6-C2H6 mixtures discharge mode αionization avalanche

pulsed UV Laser Modification of Polyester Textile Materials:Effect on Wettability

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Journal of China Textile University(English Edition) 1999年第3期16卷 31-36页

作者：黄志聪陈光杨国荣柳启瑞 The Hong Kong Polytechnic Univ Hongkong Hong Kong

There has recently been great interest in ablative photodecomposition(APD), notably in pulsed UV laser treatment on polymers, for modification of physical and chemical properties, such as dyeability, printability, adhesion, Iuster and many more. Very little attention was focused, however, on the property of wetting behaviour,which is one of the most fundamental properties in affecting polymer science. Poly(ethylene terephthalate) (PET) fibers drawn to two different draw ratios and under two temperatures, and three white knitted polyester fabrics made of 100% PET fibre were used to investigate their wetting behaviour due to excimer laser treatment.Experiments like water contact angle measurement, vertical drop test and moisture regain were conducted upon samples and all results give the same conclusion that laser treatment increases the hydrophobicity of all samples tested. Scanning electron microscope (SEM) observation reveals how the morphological modification of polymers by laser treatment is

关键词： polyester wettability modification pulsed UV laser SEM.

Investigation of the self-induced magnetic field characteristics in a pulsed plasma thruster with flared electrodes

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Plasma Science and Technology 2020年第3期22卷 46-53页

作者：刘祺杨磊黄玉平赵絮郑再平 Beijing Research Institute of Precise Mechatronics and Controls Beijing 100076People’s Republic of China

The self-induced magnetic field in a pulsed plasma thruster(PPT)with flared electrodes is investigated for a better understanding of the working process and the structural design of the thruster.A two-dimensional model of the magnetic field is built and is validated by comparing the simulated results with the experimental results in literature.The magnetic flux density in the discharge channel during the working process is presented and analyzed regarding the electrode structures.The calculated magnetic field flux density decreases from 0.8 T at the upstream to 0.1 T and below at the downstream in the discharge channel(68 J).The peak of the magnetic flux density over time lags behind the current peak,which provides evidence for the existence of a moving plasma sheet in the discharge process.The magnetic field induced by the current in the extra bending part of the anode enhances the Lorentz force,which acts on the charged particles near the propellant.Finally,the geometric study indicates that the electromagnetic impulse bit does not monotonically increase with the flared angle of the electrodes.Instead,it reaches a maximum at a certain flared angle,which could provide significant suggestions for structural optimization.

关键词： pulsed plasma thruster numerical investigation magnetic flux density flared electrodes