Chemical effects in different aqueous solutions induced by plasma with glow discharge electrolysis (GDE) and contact glow discharge electrolysis (CGDE) are described in this paper. The experimental and discharge char...Chemical effects in different aqueous solutions induced by plasma with glow discharge electrolysis (GDE) and contact glow discharge electrolysis (CGDE) are described in this paper. The experimental and discharge characteristics are also reviewed. These are followed by a discussion of their mechanisms of both anodic and cathodic CGDE..展开更多
The nanosecond single pulse was employed here to generate a large volume glow discharge between the wire-plane electrodes in air. In order to find requirements on pulse waveform for generation of a large volume discha...The nanosecond single pulse was employed here to generate a large volume glow discharge between the wire-plane electrodes in air. In order to find requirements on pulse waveform for generation of a large volume discharge at atmospheric pressure, the effect of pulse risetime, pulse width, and amplitude on glow discharge has been widely investigated in this paper. Results reveal that a large volume glow discharge can be generated in an inhomogeneous electric field under the single pulse with the faster risetime, the lower peak amplitude. The pulse width has almost no influence on the density of glow discharge, but which has a great influence on the transition from glow discharge to streamer discharge. A model of inter-shielding-effect has been proposed to explain the influence of waveform parameters on pulsed glow discharge.展开更多
The dielectric barrier discharge （DBD） in the glow regime in neon has been investigated by experiment and two-dimensional （2D） fluid modeling. The discharge was carried out in a planar DBD system with segmented-el...The dielectric barrier discharge （DBD） in the glow regime in neon has been investigated by experiment and two-dimensional （2D） fluid modeling. The discharge was carried out in a planar DBD system with segmented-electrodes driven by square-wave voltage. The results show that the glow DBD originates in the center of the electrode and expands outward to the electrode edge during each half cycle of the voltage, forming a radial structure. The discharge decays firstly in the inner area but sustains longer in the edge area, showing a reversed discharge area. The discharge cannot completely cover the entire electrode surface, but remains a border of nonor weak discharge. The fluid modeling shows a similar result in agreement with the experiments. The simulations indicate that the electric field in the edge area is distorted due to the boundary effect so that the electric field and charge distribution are different from that in the inner part. The distorted field reduces the longitudinal component near the edge and causes the local field to be lower than that in the center, and hence makes the discharge behindhand. It also induces a transverse field that makes the discharge extend radially outward to the edge. The boundary effect plays an important role in the glow DBD structure.展开更多
Polytetrafluoroethylene films are treated by room temperature helium atmospheric pressure plasma plumes, which are generated with a home-made single liquid electrode plasma device. After plasma treatment, the water co...Polytetrafluoroethylene films are treated by room temperature helium atmospheric pressure plasma plumes, which are generated with a home-made single liquid electrode plasma device. After plasma treatment, the water contact angle of polytetrafiuoroethylene fihn drops from 114° to 46° and the surface free energy increases from 22.0 mJ/m2 to 59.1 mJ/m2. The optical emission spectrum indicates that there are reactive species such as O2＋, O and He in the plasma plume. After plasma treatment, a highly crosslinking structure is formed on the fihn surface and the oxygen element is incorporated into the film surface in the forms of C O-C-, -C=O, and O C=O groups. Over a period of 10 days, the contact angle of the treated film is recovered by only about 10°, which indicates that the plasma surface modification is stable with time.展开更多
Non-thermal equilibrium atmospheric pressure plasma jet（APPJ）is a cold plasma source that promises various innovative applications,and the uniform APPJ is more favored.Glow discharge is one of the most effective met...Non-thermal equilibrium atmospheric pressure plasma jet（APPJ）is a cold plasma source that promises various innovative applications,and the uniform APPJ is more favored.Glow discharge is one of the most effective methods to obtain the uniform discharge.Compared with the glow dielectric barrier discharge（DBD）in atmospheric pressure,pure helium APPJ shows partial characteristics of both the glow discharge and the streamer.In this paper,considering the influence of the Penning effect,the electrical and optical properties of He APPJ and Ar/NH3APPJ were researched.A word＂Glow-like APPJ＂is used to characterize the uniformity of APPJ,and it was obtained that the basic characteristics of the glow-like APPJ are driven by the k Hz AC high voltage.The results can provide a support for generating uniform APPJ,and lay a foundation for its applications.展开更多
The paper presents a physical model of a natural phenomenon, the glow of bubbles at hydrothermal vents formed during underwater volcanic activity. The basis of the model is characteristic non-equilibrium radiation und...The paper presents a physical model of a natural phenomenon, the glow of bubbles at hydrothermal vents formed during underwater volcanic activity. The basis of the model is characteristic non-equilibrium radiation under first order phase transitions that since 2010 has been referred to as the PeTa (Perelman-Tatartchenko) effect. This is the fourth paper in a series developing the model for similar physical phenomena: cavitational luminescence (CL), multi-bubble sonoluminescence (MBSL), single-bubble sonoluminescence (SBSL) and laser-induced bubble luminescence (LIBL). The previous three papers were published during 2017-2018 in this Journal. In the third one we have shown that above mentioned physical effects can be generalized as a phenomenon that we have titled “Vapour bubble luminescence” (VBL). VBL is very clearly represented in a non-equilibrium phase diagram. The essence of VBL is as follows: when there is a local decrease in pressure and/or an increase of temperature in a tiny volume of a liquid occurs, one or several bubbles filled with vapour will appear. Subsequently a very rapid pressure increase and/or temperature decrease in the same volume of liquid leads to supersaturation of the vapour inside the bubble. Upon reaching critical vapor density, instantaneous vapour condensation and emission of the phase transition energy that is accompanied by a flash (this is the PeTa effect) results in a sharp pressure decrease and the bubble collapses due to the pressure drop. This process is accompanied by a shock wave in the liquid. A similar effect occurs if bubbles filled with hot steam, for example from a cappuccino machine, are injected into a relatively large volume of cold water. The VBL model explains all experimental data concerning CL/MBSL/SBSL/LIBL and the relatively new natural phenomenon, the glow of bubbles at hydrothermal vents. Several model experiments demonstrate the PeTa effect under similar conditions. Additionally, we define the PeTa effect in all its manifestations on a non-equilibrium phase diagram. This clarifies which niches can contain VBL processes. We also demonstrate the window of transparency (WT) for the PeTa radiation during crystallization of a supercooled tellurium melt and propose the design of a cavity-free pulsed laser on the basis of similar crystallization processes.展开更多
The behavior of argon plasma driven by nanosecond pulsed plasma in a low-pressure plasma reactor is investigated using a global model, and the results are compared with the experimental measurements. The time evolutio...The behavior of argon plasma driven by nanosecond pulsed plasma in a low-pressure plasma reactor is investigated using a global model, and the results are compared with the experimental measurements. The time evolution of plasma density and the electron energy probability function are calculated by solving the energy balance and Boltzmann equations. During and shortly after the discharge pulse, the electron energy probability function can be represented by a bi-Maxwellian distribution, indicating two energy groups of electrons. According to the effective electron temperature calculation, we find that there are more high-energy electrons that play an important role in the excitation and ionization processes than low-energy electrons. The effective electron temperature is also measured via optical emission spectroscopy to evaluate the simulation model. In the comparison, the simulation results are found to be in agreement with the measure- ments. Furthermore, variations of the effective electron temperature are presented versus other discharge parameters, such as pulse width time, pulse rise time and gas pressure.展开更多
文摘Chemical effects in different aqueous solutions induced by plasma with glow discharge electrolysis (GDE) and contact glow discharge electrolysis (CGDE) are described in this paper. The experimental and discharge characteristics are also reviewed. These are followed by a discussion of their mechanisms of both anodic and cathodic CGDE..
文摘The nanosecond single pulse was employed here to generate a large volume glow discharge between the wire-plane electrodes in air. In order to find requirements on pulse waveform for generation of a large volume discharge at atmospheric pressure, the effect of pulse risetime, pulse width, and amplitude on glow discharge has been widely investigated in this paper. Results reveal that a large volume glow discharge can be generated in an inhomogeneous electric field under the single pulse with the faster risetime, the lower peak amplitude. The pulse width has almost no influence on the density of glow discharge, but which has a great influence on the transition from glow discharge to streamer discharge. A model of inter-shielding-effect has been proposed to explain the influence of waveform parameters on pulsed glow discharge.
基金supported by National Natural Science Foundation of China(No.11175017)
文摘The dielectric barrier discharge （DBD） in the glow regime in neon has been investigated by experiment and two-dimensional （2D） fluid modeling. The discharge was carried out in a planar DBD system with segmented-electrodes driven by square-wave voltage. The results show that the glow DBD originates in the center of the electrode and expands outward to the electrode edge during each half cycle of the voltage, forming a radial structure. The discharge decays firstly in the inner area but sustains longer in the edge area, showing a reversed discharge area. The discharge cannot completely cover the entire electrode surface, but remains a border of nonor weak discharge. The fluid modeling shows a similar result in agreement with the experiments. The simulations indicate that the electric field in the edge area is distorted due to the boundary effect so that the electric field and charge distribution are different from that in the inner part. The distorted field reduces the longitudinal component near the edge and causes the local field to be lower than that in the center, and hence makes the discharge behindhand. It also induces a transverse field that makes the discharge extend radially outward to the edge. The boundary effect plays an important role in the glow DBD structure.
基金Project supported by the State Key Program of National Natural Science Foundation of China (Grant No. 10735090)the Young Scientist Fund of the National Natural Science Foundation of China (Grant No. 11005151)
文摘Polytetrafluoroethylene films are treated by room temperature helium atmospheric pressure plasma plumes, which are generated with a home-made single liquid electrode plasma device. After plasma treatment, the water contact angle of polytetrafiuoroethylene fihn drops from 114° to 46° and the surface free energy increases from 22.0 mJ/m2 to 59.1 mJ/m2. The optical emission spectrum indicates that there are reactive species such as O2＋, O and He in the plasma plume. After plasma treatment, a highly crosslinking structure is formed on the fihn surface and the oxygen element is incorporated into the film surface in the forms of C O-C-, -C=O, and O C=O groups. Over a period of 10 days, the contact angle of the treated film is recovered by only about 10°, which indicates that the plasma surface modification is stable with time.
基金supported by National Natural Science Foundation of China(Nos.51307133,51125029,51221005)the Fundamental Research Funds for the Central Universities of China(Nos.xjj2012132,xkjc2013004)
文摘Non-thermal equilibrium atmospheric pressure plasma jet（APPJ）is a cold plasma source that promises various innovative applications,and the uniform APPJ is more favored.Glow discharge is one of the most effective methods to obtain the uniform discharge.Compared with the glow dielectric barrier discharge（DBD）in atmospheric pressure,pure helium APPJ shows partial characteristics of both the glow discharge and the streamer.In this paper,considering the influence of the Penning effect,the electrical and optical properties of He APPJ and Ar/NH3APPJ were researched.A word＂Glow-like APPJ＂is used to characterize the uniformity of APPJ,and it was obtained that the basic characteristics of the glow-like APPJ are driven by the k Hz AC high voltage.The results can provide a support for generating uniform APPJ,and lay a foundation for its applications.
文摘The paper presents a physical model of a natural phenomenon, the glow of bubbles at hydrothermal vents formed during underwater volcanic activity. The basis of the model is characteristic non-equilibrium radiation under first order phase transitions that since 2010 has been referred to as the PeTa (Perelman-Tatartchenko) effect. This is the fourth paper in a series developing the model for similar physical phenomena: cavitational luminescence (CL), multi-bubble sonoluminescence (MBSL), single-bubble sonoluminescence (SBSL) and laser-induced bubble luminescence (LIBL). The previous three papers were published during 2017-2018 in this Journal. In the third one we have shown that above mentioned physical effects can be generalized as a phenomenon that we have titled “Vapour bubble luminescence” (VBL). VBL is very clearly represented in a non-equilibrium phase diagram. The essence of VBL is as follows: when there is a local decrease in pressure and/or an increase of temperature in a tiny volume of a liquid occurs, one or several bubbles filled with vapour will appear. Subsequently a very rapid pressure increase and/or temperature decrease in the same volume of liquid leads to supersaturation of the vapour inside the bubble. Upon reaching critical vapor density, instantaneous vapour condensation and emission of the phase transition energy that is accompanied by a flash (this is the PeTa effect) results in a sharp pressure decrease and the bubble collapses due to the pressure drop. This process is accompanied by a shock wave in the liquid. A similar effect occurs if bubbles filled with hot steam, for example from a cappuccino machine, are injected into a relatively large volume of cold water. The VBL model explains all experimental data concerning CL/MBSL/SBSL/LIBL and the relatively new natural phenomenon, the glow of bubbles at hydrothermal vents. Several model experiments demonstrate the PeTa effect under similar conditions. Additionally, we define the PeTa effect in all its manifestations on a non-equilibrium phase diagram. This clarifies which niches can contain VBL processes. We also demonstrate the window of transparency (WT) for the PeTa radiation during crystallization of a supercooled tellurium melt and propose the design of a cavity-free pulsed laser on the basis of similar crystallization processes.
基金supported by National Natural Science Foundation of China (Nos.10875023,11175035)the Ph.D research program(No.200801411040 ) of Educational Ministry+1 种基金the Scientific and Technical Foundation of Liaoning Province (No.20082168)National Magnetic Confinement Fusion Science Program of China (Nos.2009GB106004,2008CB717801)
文摘The behavior of argon plasma driven by nanosecond pulsed plasma in a low-pressure plasma reactor is investigated using a global model, and the results are compared with the experimental measurements. The time evolution of plasma density and the electron energy probability function are calculated by solving the energy balance and Boltzmann equations. During and shortly after the discharge pulse, the electron energy probability function can be represented by a bi-Maxwellian distribution, indicating two energy groups of electrons. According to the effective electron temperature calculation, we find that there are more high-energy electrons that play an important role in the excitation and ionization processes than low-energy electrons. The effective electron temperature is also measured via optical emission spectroscopy to evaluate the simulation model. In the comparison, the simulation results are found to be in agreement with the measure- ments. Furthermore, variations of the effective electron temperature are presented versus other discharge parameters, such as pulse width time, pulse rise time and gas pressure.
