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Effect of driving frequency on electron heating in capacitively coupled RF argon glow discharges at low pressure 被引量:1
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作者 Tagra Samir 刘悦 +1 位作者 赵璐璐 周艳文 《Chinese Physics B》 SCIE EI CAS CSCD 2017年第11期329-337,共9页
A one-dimensional(1D) fluid model on capacitively coupled radio frequency(RF) argon glow discharge between parallel-plates electrodes at low pressure is established to test the effect of the driving frequency on e... A one-dimensional(1D) fluid model on capacitively coupled radio frequency(RF) argon glow discharge between parallel-plates electrodes at low pressure is established to test the effect of the driving frequency on electron heating. The model is solved numerically by a finite difference method. The numerical results show that the discharge process may be divided into three stages: the growing rapidly stage, the growing slowly stage, and the steady stage. In the steady stage,the maximal electron density increases as the driving frequency increases. The results show that the discharge region has three parts: the powered electrode sheath region, the bulk plasma region and the grounded electrode sheath region. In the growing rapidly stage(at 18 μs), the results of the cycle-averaged electric field, electron temperature, electron density, and electric potentials for the driving frequencies of 3.39, 6.78, 13.56, and 27.12 MHz are compared, respectively. Furthermore,the results of cycle-averaged electron pressure cooling, electron ohmic heating, electron heating, and electron energy loss for the driving frequencies of 3.39, 6.78, 13.56, and 27.12 MHz are discussed, respectively. It is also found that the effect of the cycle-averaged electron pressure cooling on the electrons is to "cool" the electrons; the effect of the electron ohmic heating on the electrons is always to "heat" the electrons; the effect of the cycle-averaged electron ohmic heating on the electrons is stronger than the effect of the cycle-averaged electron pressure cooling on the electrons in the discharge region except in the regions near the electrodes. Therefore, the effect of the cycle-averaged electron heating on the electrons is to "heat" the electrons in the discharge region except in the regions near the electrodes. However, in the regions near the electrodes, the effect of the cycle-averaged electron heating on the electron is to "cool" the electrons. Finally, the space distributions of the electron pressure cooling the electron ohmic heating and the electron heating at 1/4 T, 2/4 T, 3/4 T, and 4/4 T in one RF-cycle are presented and compared. 展开更多
关键词 capacitively coupled plasmas electron heating radio frequency(RF) glow discharges driving frequency
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A Cross-interaction Phenomenon between Two DC Glow Discharges
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作者 李家全 童洪辉 +1 位作者 李国盛 董玉英 《Plasma Science and Technology》 SCIE EI CAS CSCD 2002年第2期1193-1196,共4页
A cross-interaction phenomenon between two dc glow discharges has been observed.We have studied the feature and variation regularty of the cross-interaction. A part of results arepresented in this paper.
关键词 VB A Cross-interaction Phenomenon between Two DC glow discharges THAN DC
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Spatial distribution of electron characteristic in argon rf glow discharges 被引量:3
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作者 祝祖送 林揆训 +3 位作者 林璇英 邱桂明 余云鹏 罗以琳 《Chinese Physics B》 SCIE EI CAS CSCD 2006年第5期969-974,共6页
The spatial distributions of the electron density and the mean electron energy of argon radio frequency (rf) glow discharge plasma in a plasma-enhanced chemical vapour deposition (PECVD) system have been investiga... The spatial distributions of the electron density and the mean electron energy of argon radio frequency (rf) glow discharge plasma in a plasma-enhanced chemical vapour deposition (PECVD) system have been investigated using an established movable Langmuir probe. The results indicate that in the axial direction the electron density tends to peak at midway between the two electrodes while the axial variation trend of mean electron energy is different from that of the electron density, the mean electron energy is high near the electrodes. And the mean electron energy near the cathode is much higher than that near the anode. This article focuses on the radial distribution of electron density and mean electron energy. A proposed theoretical model distribution agrees well with the experimental one: the electron density and the mean electron energy both increase from the centre of the glow to the edge of electrodes. This is useful for better understanding the discharge mechanism and searching for a better deposition condition to improve thin film quality. 展开更多
关键词 spatial distribution of electron characteristic a movable Langmuir probe radio frequency glow discharge
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Simulation Study on the Self-Sustained Oscillations in DC Driven Glow Discharges at Atmospheric Pressure Under Different Gas Gaps 被引量:1
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作者 王晓菲 贺亚峰 刘富成 《Plasma Science and Technology》 SCIE EI CAS CSCD 2015年第6期461-468,共8页
In this paper, a one-dimensional plasma fluid model is employed to study the self- sustained oscillations in DC-driven helium glow discharges at atmospheric pressure under different gas gaps. Our simulation results in... In this paper, a one-dimensional plasma fluid model is employed to study the self- sustained oscillations in DC-driven helium glow discharges at atmospheric pressure under different gas gaps. Our simulation results indicate that a harmonic current oscillation with tiny amplitude always occur at the onset of instability and transits into a relaxation one as the conductivity of the semiconductor is decreased. It is found that the dynamics of the oscillations are dependent on the gas gaps. The discharge can only exhibit a simple oscillation with unique amplitude and frequency at smaller gas gaps (〈2 mm) while it can exhibit a more complex oscillation with several different amplitudes and frequencies at larger gas gaps (〉2 mm). The discharge modes in these current oscillations have also been analyzed. 展开更多
关键词 OSCILLATION Townsend discharge glow discharge subnormal glow discharge discharge mode
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Oxidative Degradation of o-Chlorophenol with Contact Glow Discharges in Aqueous Solution 被引量:1
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作者 高锦章 陈平 +3 位作者 杨武 纳鹏君 刘永军 陆泉芳 《Plasma Science and Technology》 SCIE EI CAS CSCD 2003年第1期1609-1614,共6页
Contact glow discharge electrolysis (CGDE) of o-chlorophenol (2-CP) was investigated under different pH, voltages and initial concentrations. And the mechanism of the oxidation was explored. The results suggested that... Contact glow discharge electrolysis (CGDE) of o-chlorophenol (2-CP) was investigated under different pH, voltages and initial concentrations. And the mechanism of the oxidation was explored. The results suggested that the degradation followed the first order kinetic law; Fe2+ had a remarkable catalytic effect on the removal rate of o-chloropenol. In the presence of Fe2+, 2-CP underwent an exhaustive degradation, from which the major intermediates included o-dihydroxybenze, p-hydroxybenze, p-benzoquione and carboxlic acids. 展开更多
关键词 contact glow discharge electrolysis O-CHLOROPHENOL PLASMA oxidative degradation
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Gas Breakdown of Radio Frequency Glow Discharges in Helium at near Atmospheric Pressure 被引量:1
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作者 刘新坤 徐金洲 +3 位作者 崔桐菲 郭颖 张菁 石建军 《Plasma Science and Technology》 SCIE EI CAS CSCD 2013年第7期623-626,共4页
A one-dimensional self-consistent fluid model was developed for radio frequency glow discharge in helium at near atmospheric pressure, and was employed to study the gas breakdown characteristics in terms of breakdown ... A one-dimensional self-consistent fluid model was developed for radio frequency glow discharge in helium at near atmospheric pressure, and was employed to study the gas breakdown characteristics in terms of breakdown voltage. The effective secondary electron emission coefficient and the effective electric field for ions were demonstrated to be important for determining the breakdown voltage of radio frequency glow discharge at near atmospheric pressure. The constant of A was estimated to be 64:t=4 cm-lTorr-1, which was proportional to the first Townsend coefficient and could be employed to evaluate the gas breakdown voltage. The reduction in the breakdown voltage of radio frequency glow discharge with excitation frequency was studied and attributed to the electron trapping effect in the discharge gap. 展开更多
关键词 radio frequency glow discharge gas breakdown numerical simulation
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Operation Mode on Pulse Modulation in Atmospheric Radio Frequency Glow Discharges 被引量:1
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作者 张杰 郭颖 +2 位作者 黄晓江 张菁 石建军 《Plasma Science and Technology》 SCIE EI CAS CSCD 2016年第10期974-977,共4页
The discharge operation regime of pulse modulated atmospheric radio frequency (RF) glow discharge in helium is investigated on the duty cycle and frequency of modulation pulses. The characteristics of radio frequenc... The discharge operation regime of pulse modulated atmospheric radio frequency (RF) glow discharge in helium is investigated on the duty cycle and frequency of modulation pulses. The characteristics of radio frequency discharge burst in terms of breakdown voltage, alpha(s)- gamma(γ) mode transition voltage and current are demonstrated by the discharge current voltage characteristics. The minimum breakdown voltage of RF discharge burst was obtained at the duty cycle of 20% and frequency of 400 kHz, respectively. The α-γ mode transition of RF discharge burst occurs at higher voltage and current by reducing the duty cycle and elevating the modulation frequency before the RF discharge burst evolving into the ignition phase, in which the RF discharge burst can operate stably in the γ mode. It proposes that the intensity and stability of RF discharge burst can be improved by manipulating the duty cycle and modulation frequency in pulse modulated atmospheric RF glow discharge. 展开更多
关键词 pulse modulation atmospheric glow discharge discharge operation mode
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Electrical Characteristics of Pseudoglow Discharges in Helium under Atmospheric Pressure
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作者 除旭 欧琼荣 +2 位作者 钟少锋 舒兴胜 孟月东 《Plasma Science and Technology》 SCIE EI CAS CSCD 2006年第3期303-306,共4页
A pseudoglow discharge behaviour is achieved at a 2.0-mm dielectric-dielectric electrode gap in pure helium under atmospheric pressure. An experimental study of the pseudoglow discharges is presented. The electrical c... A pseudoglow discharge behaviour is achieved at a 2.0-mm dielectric-dielectric electrode gap in pure helium under atmospheric pressure. An experimental study of the pseudoglow discharges is presented. The electrical characteristics and the discharge photos of the pseudoglow discharges are analyzed and discussed. The current-voltage parameters of the pseudoglow dis- charges are considered in regard to the influence on their behaviour. 展开更多
关键词 dielectric barrier discharge atmospheric pressure filamentary discharge glow discharge
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Effects of gas pressure on plasma characteristics in dual frequency argon capacitive glow discharges at low pressure by a self-consistent fluid model
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作者 赵璐璐 刘悦 Tagra Samir 《Chinese Physics B》 SCIE EI CAS CSCD 2017年第12期361-370,共10页
A self-consistent fluid model for dual radio frequency argon capacitive glow discharges at low pressure is established. Numerical results are obtained by using a finite difference method to solve the model numerically... A self-consistent fluid model for dual radio frequency argon capacitive glow discharges at low pressure is established. Numerical results are obtained by using a finite difference method to solve the model numerically, and the results are analyzed to study the effect of gas pressure on the plasma characteristics. It shows that when the gas pressure increases from 0.3 Torr (1 Torr=1.33322102 Pa) to 1.5 Torr, the cycle-averaged plasma density and the ionization rate increase; the cycle-averaged ion current densities and ion energy densities on the electrodes electrode increase; the cycle-averaged electron temperature decreases. Also, the instantaneous electron density in the powered sheath region is presented and discussed. The cycle-averaged electric field has a complex behavior with the increasing of gas pressure, and its changes take place mainly in the two sheath regions. The cycle-averaged electron pressure heating, electron ohmic heating, electron heating, and electron energy loss are all influenced by the gas pressure. Two peaks of the electron heating appear in the sheath regions and the two peaks become larger and move to electrodes as the gas pressure increases. 展开更多
关键词 dual frequency gas pressure glow discharge
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Development of Numerical Model for Radio Frequency Atmospheric Pressure Glow Discharges in Argon
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作者 付平 钱宇俊 +2 位作者 宋书通 丁可 石建军 《Journal of Donghua University(English Edition)》 EI CAS 2011年第4期391-395,共5页
A one-dimensional,self-consistent fluid model is developed for a computational investigation on discharge characteristics and dynamics of radio frequency(RF) glow discharges in atmospheric argon,which are demonstrated... A one-dimensional,self-consistent fluid model is developed for a computational investigation on discharge characteristics and dynamics of radio frequency(RF) glow discharges in atmospheric argon,which are demonstrated through the spatial and temporal profiles of plasma species,electric field,and mean electron energy.Furthermore,in the discharge current density range from 7.1 mA/cm2 to 119.5 mA/cm2,different discharge operation modes of α and γ are indicated by changing differential conductivity of voltage-current characteristics and sheath dynamics in terms of sheath voltage and sheath thickness. 展开更多
关键词 atmospheric pressure glow discharge APGD numerical simulation mode transition sheath dynamics
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Numerical study on discharge characteristics influenced by secondary electron emission in capacitive RF argon glow discharges by fluid modeling
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作者 赵璐璐 刘悦 Tagra Samir 《Chinese Physics B》 SCIE EI CAS CSCD 2018年第2期415-422,共8页
A one-dimensional(1D) fluid model of capacitive RF argon glow discharges between two parallel-plate electrodes at low pressure is employed. The influence of the secondary electron emission on the plasma characterist... A one-dimensional(1D) fluid model of capacitive RF argon glow discharges between two parallel-plate electrodes at low pressure is employed. The influence of the secondary electron emission on the plasma characteristics in the discharges is investigated numerically by the model. The results show that as the secondary electron emission coefficient increases,the cycle-averaged electric field has almost no change; the cycle-averaged electron temperature in the bulk plasma almost does not change, but it increases in the two sheath regions; the cycle-averaged ionization rate, electron density, electron current density, ion current density, and total current density all increase. Also, the cycle-averaged secondary electron fluxes on the surfaces of the electrodes increase as the secondary electron emission coefficient increases. The evolutions of the electron flux, the secondary electron flux and the ion flux on the powered electrode increase as the secondary electron emission coefficient increases. The cycle-averaged electron pressure heating, electron Ohmic heating, electron heating, and ion heating in the two sheath regions increase as the secondary electron emission coefficient increases. The cycle-averaged electron energy loss increases with increasing secondary electron emission coefficient. 展开更多
关键词 RF glow discharge secondary electron emission fluid model
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Ion resonance causes striations in electronegative rf glow discharges
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《Science Foundation in China》 CAS 2016年第4期33-33,共1页
With the support by the National Natural Science Foundation of China,Dr Liu Yongxin(刘永新)and his coworkers at the Key Laboratory of Materials Modification by Laser,Ion,and Electron Beams(Ministry of Education),Schoo... With the support by the National Natural Science Foundation of China,Dr Liu Yongxin(刘永新)and his coworkers at the Key Laboratory of Materials Modification by Laser,Ion,and Electron Beams(Ministry of Education),School of Physics and Optoelectronic Technology,Dalian University of Technology,observed,for the first time,the self-organized striated structures of the plasma emission in 展开更多
关键词 TIME 刘永新 Ion resonance causes striations in electronegative rf glow discharges
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Simulation of DC glow discharge plasma with free-moving dust particles in the radial direction
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作者 田瑞焕 梁勇敢 +5 位作者 郝书吉 冯杰 江晓楠 李辉 袁承勋 吴健 《Plasma Science and Technology》 SCIE EI CAS CSCD 2023年第9期73-81,共9页
A self-consistent fluid model is developed to investigate the radial distributions of dusty plasma parameters in a DC glow discharge,in which the extended fluid approach of plasma particles and the transport equations... A self-consistent fluid model is developed to investigate the radial distributions of dusty plasma parameters in a DC glow discharge,in which the extended fluid approach of plasma particles and the transport equations of dust particles are coupled.The electrical interaction between charged dust particles is considered in the model.The time evolution of radial distributions of dust density,plasma density,the radial component of electric field and the forces acting on dust particles when dust density tends to be stable,are obtained and analyzed under different discharge currents and dust particle radii.It is shown that the dust density structure is determined mainly by the radial electrostatic force,thermophoretic force and ion drag force in the discharge tube,and both discharge current and dust particle radius have an obvious effect on the transport processes of dust particles.The dust particles gather in the central region of the discharge tube for low discharge current and small dust radius,then dust voids are formed and become wider when the discharge current and dust radius increase.The plasma parameters in the dust gathering region are obviously affected by the dust particles due to the charging processes of electrons and ions to the dust surface. 展开更多
关键词 dusty plasma glow discharge extended fluid model dust transport processes dust-void
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TREATMENT OF METALS, POLYMER FILMS, AND FABRICS WITHA ONE ATMOSPHERE UNIFORM GLOW DISCHARGE PLASMA(OAUGDP) FOR INCREASED SURFACE ENERGY AND DIRECTIONAL ETCHING 被引量:18
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作者 J. Reece Roth and Z. Y Chen (Plasma Sciences Laboratory, Department of Electrical and Computer Engineering, University of Tennessee, Knoxville, TN 37996-2100, USA) Peter P.- Y Tsai (Textiles and Nonwovens Development Center (TANDEC), University of Tenness 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 2001年第6期391-407,共17页
Direct exposure of samples to the active species of air generated by a One Atmosphere Uniform Glow Discharge Plasma (OAUGDP) has been used to etch and to increase the surface energy of metallic surfaces, photoresist, ... Direct exposure of samples to the active species of air generated by a One Atmosphere Uniform Glow Discharge Plasma (OAUGDP) has been used to etch and to increase the surface energy of metallic surfaces, photoresist, polymer films, and nonwoven fab- rics. The OAUGDP is a non-thermal plasma with the classical characteristics of a DC normal glow discharge that operates in air (and other gases) at atmospheric pres- sure. Neither a vacuum system nor batch processing is necessary. A wide range of applications to metals, photoresist, films, fabrics, and polymeric webs can be accom- modated by direct exposure of the workpiece to the plasma in parallel-plate reactors. This technolopy is simple, it produces effects that can be obtained in no other way at one atmosphere; it generates minimal pollutants or unwanted by-products; and it is suitable for individual sample or online treatment of metallic surfaces, wafers, films, and fabrics. Early exposures of solid materials to the OAUGDP required minutes to produce rela- tively small increases of surface energy. These durations appeared too long for com- mercial application to fast-moving webs. Recent improvements in OAUGDP gas com- position, power density, plasma quality, recireulating gas flow, and impedance match- ing of the power supply to the parallel plate plasma reactor have made it possible to raise the surface energy of a variety of polymeric webs (PP, PET PE etc.) to levels of 60 to 70 dynes/cm with one second of exposure. In air plasmas, the high surface ener- gies are not durable, and fall to 50 dynes/cm after periods of weeks to months. Here, we report the exposure of metallic surfaces, photoresist, polymeric films, and nonwo- ven fabrics made of PP and PET to an impedance matched parallel plate OAUGDP for durations ranging from one second to several tens of seconds. Data will be re- ported on the surface energy, wettability, wickability, and aging effect of polymeric films and fabrics as functions of time of exposure, and time after exposure; the rate and uniformity of photoresist etching; and the production of sub-micron structures by OAUGDP etching at one atmosphere. 展开更多
关键词 atmosphere glow discharge plasma surface energy etching of material surface
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Surface Treatment of Polyethylene Terephthalate Film Using Atmospheric Pressure Glow Discharge in Air 被引量:6
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作者 方志 邱毓昌 王辉 《Plasma Science and Technology》 SCIE EI CAS CSCD 2004年第6期2576-2580,共5页
Non-thermal plasmas under atmospheric pressure are of great interest in polymer surface processing because of their convenience, effectiveness and low cost. In this paper, the treatment of Polyethylene terephthalate (... Non-thermal plasmas under atmospheric pressure are of great interest in polymer surface processing because of their convenience, effectiveness and low cost. In this paper, the treatment of Polyethylene terephthalate (PET) film surface for improving hydrophilicity using the non-thermal plasma generated by atmospheric pressure glow discharge (APGD) in air is conducted. The discharge characteristics of APGD are shown by measurement of their electrical discharge parameters and observation of light-emission phenomena, and the surface properties of PET before and after the APGD treatment are studied using contact angle measurement, x-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). It is found that the APGD is homogeneous and stable in the whole gas gap, which differs from the commonly filamentary dielectric barrier discharge (DBD). A short time (several seconds) APGD treatment can modify the surface characteristics of PET film markedly and uniformly. After 10 s APGD treatment, the 展开更多
关键词 non-thermal plasma dielectric barrier discharge (DBD) atmospheric pressure glow discharge (APGD) surface treatment polyethylene terephthalate (PET)
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perimental Study on the Interaction of Electromagnetic Waves and Glow Plasma 被引量:7
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作者 张芝涛 赵建森 +1 位作者 徐晓文 殷燕 《Plasma Science and Technology》 SCIE EI CAS CSCD 2011年第3期279-285,共7页
An experimental system was established in order to study the interaction between electromagnetic waves, with a frequency of 300 kHz to 3 GHz, and DC glow discharge plasma. The results show that the DC glow discharge p... An experimental system was established in order to study the interaction between electromagnetic waves, with a frequency of 300 kHz to 3 GHz, and DC glow discharge plasma. The results show that the DC glow discharge plasma affects the transmission properties of elec- tromagnetic waves, while the waves can change both temperature and density of electrons. 展开更多
关键词 PLASMA electromagnetic wave interaction glow discharge
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Oxidative Degradation of 4-chlorophenol in Aqueous Induced by Plasma with Submersed Glow Discharge Electrolysis 被引量:6
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作者 蒲陆梅 高锦章 +3 位作者 杨武 李岩 俞洁 黄冬玲 《Plasma Science and Technology》 SCIE EI CAS CSCD 2005年第5期3048-3050,共3页
The oxidative degradation of 4-chlorophenol (4-CP) in aqueous solution induced by plasma with submersed glow discharge has been investigated. The concentration of 4-CP and the reaction intermediates were determined ... The oxidative degradation of 4-chlorophenol (4-CP) in aqueous solution induced by plasma with submersed glow discharge has been investigated. The concentration of 4-CP and the reaction intermediates were determined by high performance liquid chromatography (HPLC). Various influencing factors such as the initial pH, the concentration of 4-CP and the catalytic action of Fe^2+ were examined. The results indicate that 4-CP is eventually degraded into inorganic ion, dioxide carbon and water. The attack of hydroxyl radicals on the benzene rings of 4-CP in the initial stage of oxidative reactions is presumed to be a key step. They also suggest that the reaction is of a pseudo-first order kinetic reaction and the proposed method is an efficient way for the 4-CP degradation, 展开更多
关键词 PLASMA submersed glow discharged electrolysis 4-CHLOROPHENOL
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Application of the Multi-Electrode in the Degradation of Alizarin Red Induced by Glow Discharge Plasma 被引量:3
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作者 高锦章 李岩 +3 位作者 杨武 薄丽丽 俞洁 蒲陆梅 《Plasma Science and Technology》 SCIE EI CAS CSCD 2006年第2期198-201,共4页
This paper presents a novel set-up to be used in the degradation of dye, Various influencing factors, such as the voltage, the number of the anodes, and the catalytic action of Fe^2+, were examined. Chemical oxygen d... This paper presents a novel set-up to be used in the degradation of dye, Various influencing factors, such as the voltage, the number of the anodes, and the catalytic action of Fe^2+, were examined. Chemical oxygen demand (COD), ultraviolet (UV), FTIR absorption spectra, and atomic force microscopy (AFM) were used to monitor the degradation process. The results showed that the efficiency of degradation is raised by increasing the applied voltage, and is further improved when two or three anodes are used. Moreover, the use of Fe^2+ ion can promote the degradation reaction and shorten the degradation time. So the multi-electrode instrument is more efficient in degrading the dye and should be further studied. 展开更多
关键词 glow discharge plasma MULTI-ELECTRODE DEGRADATION alizarin red
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Determination of trace impurity elements in MnZn ferrite powder by direct current glow discharge mass spectrometry 被引量:3
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作者 FU Liang MA Jun-cai SHI Shu-yun 《Journal of Central South University》 SCIE EI CAS CSCD 2018年第7期1590-1597,共8页
An analytical method for the determination of 26 impurity elements (such as Li, Be, Na, Mg, Al, Si, P, S, K, Ca, Sc, Ti, V, Cr, Co, Ni, Ga, Ge, Y, Nb, Mo, Ag, Cd, Sb, W and Pb) in MnZn ferrite powder by direct curre... An analytical method for the determination of 26 impurity elements (such as Li, Be, Na, Mg, Al, Si, P, S, K, Ca, Sc, Ti, V, Cr, Co, Ni, Ga, Ge, Y, Nb, Mo, Ag, Cd, Sb, W and Pb) in MnZn ferrite powder by direct current glow discharge mass spectrometry (GD-MS) was established. MnZn ferrite powder was mixed with copper powder, used as a conductor, and pressed. The effects of MnZn ferrite powder preparation conditions and glow discharge parameters for the sensitivity and stability of signal analysis were investigated. By determining the choice of isotope and the application of the mass resolutions of 4000 (MR, medium resolution) and 10000 (HR, high resolution), mass spectral interference was eliminated. The contents of impurity elements in MnZn ferrite powder was calculated by subtraction after normalizing the total signal of Mn, Zn, Fe, O and Cu. The results showed that the detection limit of 26 kinds of impurity elements was between 0.002 and 0.57 μg/g, and the relative standard deviation (RSD) was between 3.33% and 32.35%. The accuracy of this method was verified by the ICP-MS. The method was simple and practical, which is applied to the determination of impurity elements in MnZn ferrite powder. 展开更多
关键词 MnZn ferrite powder glow discharge mass spectrometry impurity elements copper powder
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Numerical studies of atmospheric pressure glow discharge controlled by a dielectric barrier between two coaxial electrodes 被引量:2
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作者 张红艳 王德真 王晓钢 《Chinese Physics B》 SCIE EI CAS CSCD 2007年第4期1089-1096,共8页
The glow discharge in pure helium at atmospheric pressure, controlled by a dielectric barrier between coaxial electrodes, is investigated based on a one-dimensional self-consistent fluid model. By solving the continui... The glow discharge in pure helium at atmospheric pressure, controlled by a dielectric barrier between coaxial electrodes, is investigated based on a one-dimensional self-consistent fluid model. By solving the continuity equations for electrons, ions, and excited atoms, with the current conservation equation and the electric field profile, the time evolution of the discharge current, gas voltage and the surface density of charged particles on the dielectric barrier are calculated. The simulation results show that the peak values of the discharge current, gas voltage and electric field in the first half period are asymmetric to the second half. When the current reaches its positive or negative maximum, the electric field profile, and the electron and ion densities represent similar properties to the typical glow discharge at low pressures. Obviously there exist a cathode fall, a negative glow region, and a positive column. Effects of the barrier position in between the two coaxial electrodes and the discharge gap width on discharge current characteristics are also analysed. The result indicates that, in the case when the dielectric covering the outer electrode only, the gas is punctured earlier during the former half period and later during the latter half period than other cases, also the current peak value is higher, and the difference of pulse width between the two half periods is more obvious. On reducing the gap width, the multiple current pulse discharge happens. 展开更多
关键词 dielectric barrier discharges atmosphere pressure glow discharge PLASMA numerical simulation
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