Birds of paradise are bright and colorful birds found in the rainforests of Papua New Guinea,eastern Indonesia and northern Australia.There are 45 known species,and a new study has found that 37 of them can glow using...Birds of paradise are bright and colorful birds found in the rainforests of Papua New Guinea,eastern Indonesia and northern Australia.There are 45 known species,and a new study has found that 37 of them can glow using biofluorescence(生物荧光).This is when a living thing absorbs light and gives it off again in a different color.展开更多
Double glow plasma surface metallurgy technique was used to fabricate a Fe?Al?Cr?Nb alloyed layer onto the surface of the 45 steel. The microstructures and composition of th?eA Fl?eCr?Nb alloyed layer were analyzed by...Double glow plasma surface metallurgy technique was used to fabricate a Fe?Al?Cr?Nb alloyed layer onto the surface of the 45 steel. The microstructures and composition of th?eA Fl?eCr?Nb alloyed layer were analyzed by scanning electronic microscopy, X-ray diffraction and energy dispersive spectroscopy. The results indicate thatthe 20 μm alloyed layer is homogeneous and compact. The alloyed elements exhibit a gradient distribution along the cross section. Microhardness and nanoindentation tests imply that the surface hardness of the alloyed layer reaches HV 580, which is almost 2.8 times that of the substrate. Compared with the substrate, the alloyed layer has a much smaller displacement and a larger elastic modulus. According to the friction and wear tests at room temperature, the? FeAl?Cr?Nb alloyed layer has lower friction coefficient and less wear mass, implying that the Fe?Al?Cr?Nb alloyed layer can effectively improve the surface hardness and wear resistance of the substrate.展开更多
As a kind of microplasma sustained in air,solution electrode glow discharge(SEGD)ignited between the liquid electrode and metal electrode is attractive to the fields of optical emission spectrometry and mass spectrome...As a kind of microplasma sustained in air,solution electrode glow discharge(SEGD)ignited between the liquid electrode and metal electrode is attractive to the fields of optical emission spectrometry and mass spectrometry due to its unique advantages,such as low power consumption and low carrier gas consumption.Moreover,the complex and efficient reactions in the liquid phase and plasma phase of SEGD make it considerable research potential in the fields of biology and medicine,material synthesis,electrochemistry.Considering the close relationship between the various fields on SEGD,here we are devoted to provide an overview of the development of SEGD in various fields.More importantly,a systematic discussion on the discharge mechanism is conducted based on the research process in various fields for getting deeper insight into the SEGD.展开更多
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
Through the study of the thermoluminescence(TL) of BaFClxBr1-x: Sm(0<x<1) system, it is found that former assignment of the glow peaks of BaFX(X = Cl, Br) is plausible. Through detailed study by several methods ...Through the study of the thermoluminescence(TL) of BaFClxBr1-x: Sm(0<x<1) system, it is found that former assignment of the glow peaks of BaFX(X = Cl, Br) is plausible. Through detailed study by several methods and techniques, a correct assignment is given in this paper, i.e. the first, second, and third glow peaks of BaFClxBr1-xSm are assigned to F(F-), F(Cl-), F(Br-) centers respectively, and the first andsecond glow peaks of BaFX are assigned to F(F-) and F(X-) centers respectively. This results are confirmed by theoretical consideration. Possible reasons for former plausible assignment are also pointed out here.展开更多
Resistance and capacity-coupled glow discharge （RCCGD） is a new method to produce atmospheric pressure glow discharge in air. In RCCGD, each electrode is connected with both a resistor R and a capacitor C. The R and...Resistance and capacity-coupled glow discharge （RCCGD） is a new method to produce atmospheric pressure glow discharge in air. In RCCGD, each electrode is connected with both a resistor R and a capacitor C. The R and C can provide a negative feedback to prevent the transition from glow to spark discharge. The influence of coupled resistance, coupled capacity, inter-electrode gap and power source frequency on the discharge is studied and discussed.展开更多
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
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
Double glow plasma technique has a high deposition rate for preparing iridium coating. However, the glow plasma can influence the structure of the coating at the single substrate edge. In this study, the iridium coati...Double glow plasma technique has a high deposition rate for preparing iridium coating. However, the glow plasma can influence the structure of the coating at the single substrate edge. In this study, the iridium coating was prepared by double glow plasma on the surface of single niobium substrate. The microstructure of iridium coating at the substrate edge was observed by scanning electron microscopy. The composition of the coating was confirmed by energy dispersive spectroscopy and X-ray diffraction. There was a boundary between the coating and the substrate edge. The covered area for the iridium coating at the substrate edge became fewer and fewer from the inner area to the outer flange-area. The bamboo sprout-like particles on the surface of the substrate edge were composed of elemental niobium. The substrate edge was composed of the Nb coating and there was a transition zone between the Ir coating and the Nb coating. The interesting phenomenon of the substrate edge could be attributed to the effects of the bias voltages and the plasma cloud in the deposition chamber. The substrate edge effect could be mitigated or eliminated by adding lots of small niobium plates around the substrate in a deposition process.展开更多
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
Oxidation resistance coatings of Ir-40 at.% Zr and Ir were produced onto Mo substrates by double glow plasma technology. The oxidation resistances of the coatings were evaluated at high temperature. Ir-Zr coating cons...Oxidation resistance coatings of Ir-40 at.% Zr and Ir were produced onto Mo substrates by double glow plasma technology. The oxidation resistances of the coatings were evaluated at high temperature. Ir-Zr coating consisted of two layers： the primary layer close to the substrate was composed of dense columnar grains and the second layer was composed of dense grains of nanometric size. The mass gain of Ir coating above 800℃ was about 1.35% due to the formation of solid IrO2. The mass loss of Ir coating was about 5.3% due to the formation of gaseous oxide IrO3 when being held at 1227 ℃ for 30 min. The substrate was protected more effectively by multilayer than monolayer coating of Ir in oxidizing environment. The Ir-Zr coating was well bonded to the substrate after oxidation at 800℃. After oxidation at 1000℃, the Ir-Zr coating was poorly bonded to the substrate. The oxidation resistance of Ir-Zr coating was poor due to high content of Zr.展开更多
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
Pure Ir coating was produced by double nism of the Ir coating was investigated. glow plasma technology. Growth mecha- The Ir coating was composed of irregular compacted columnar grains with lots of nanovoids appeared ...Pure Ir coating was produced by double nism of the Ir coating was investigated. glow plasma technology. Growth mecha- The Ir coating was composed of irregular compacted columnar grains with lots of nanovoids appeared on the interface between the coating and the substrate. The Ir coating was polycrystalline with a preferred （220） orientation due to the initial nuclei with preferred growth on the surface of the substrate. The formation mechanism of the Ir coating depended on kinetic adsorp- tion and diffusion process with nucleation, coalescence and thickness growth. At the beginning of the deposition process, the growth mode of the coating was mainly con- trolled by the nucleation rate. Due to the low substrate temperature resulting in low mobility of the deposited atoms, some micropores and nanoviods were present at the interface. With the deposition process, the substrate temperature was increased and then kept steady. The growth of the coating was governed by the growth rate. The high substrate temperature supported enough energy to surface mobilitv of adatoms.展开更多
Exhaustive mineralization of pentachlorophenolate ion（PCP） in phosphate buffer was carried out using anodic contact glow discharge electrolysis（CGDE）,in which plasma was sustained between the electrolyte and anode...Exhaustive mineralization of pentachlorophenolate ion（PCP） in phosphate buffer was carried out using anodic contact glow discharge electrolysis（CGDE）,in which plasma was sustained between the electrolyte and anode.During CGDE,PCP degraded smoothly.The amount of total organic carbon decreased significantly,indicating the eventual conversion of the carbon atoms of benzene nucleus to inorganic carbons.Furthermore,chlorine atoms in PCP were liberated as chloride ions.As a primary intermediate product,2,3,5,6tetrachloro-1,4-benzoquinone was detected,and oxalate and formate as byproducts were also found.It was revealed that disappearance of PCP obeyed first-order kinetics.The reaction rate was generally unaffected by both O2 and inert gases in the cell,although it decreased by raising initial pH of solution.In addition,a plausible reaction pathway involving hydroxyl radical was proposed.展开更多
A novel plasma atmospheric pressure abnormal glow discharge was used to investigate synthesis gas production from reforming methane and carbon dioxide. Special attentions were paid to the discharge characteristics and...A novel plasma atmospheric pressure abnormal glow discharge was used to investigate synthesis gas production from reforming methane and carbon dioxide. Special attentions were paid to the discharge characteristics and CH4, CO2 conversion, H2, CO selectivity, and ratio of H2/CO varied with the changing of discharging power, the total flux, and the ratio of CH4/CO2. Experiments were performed in wider operation variables, the discharging power of 240 to 600 W, the CH4/CO2 of 0.2 to 1.0 and the total flux of 140 to 500mL/min. The experiments showed that the conversion of CH4 and CO2 was up to 91.9% and 83.2%, the selectivity of CO and H2 was also up to 80% and 90% and H2/CO mole ratio was 0.2 to 1.2, respectively. A brief analysis for discharge characteristics and the experimental results were given.展开更多
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
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
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
文摘Birds of paradise are bright and colorful birds found in the rainforests of Papua New Guinea,eastern Indonesia and northern Australia.There are 45 known species,and a new study has found that 37 of them can glow using biofluorescence(生物荧光).This is when a living thing absorbs light and gives it off again in a different color.
基金Project(51371097)supported by the National Natural Science Foundation of ChinaProject supported by the Priority Academic Program Development of Jiangsu Higher Education Institutions,China
文摘Double glow plasma surface metallurgy technique was used to fabricate a Fe?Al?Cr?Nb alloyed layer onto the surface of the 45 steel. The microstructures and composition of th?eA Fl?eCr?Nb alloyed layer were analyzed by scanning electronic microscopy, X-ray diffraction and energy dispersive spectroscopy. The results indicate thatthe 20 μm alloyed layer is homogeneous and compact. The alloyed elements exhibit a gradient distribution along the cross section. Microhardness and nanoindentation tests imply that the surface hardness of the alloyed layer reaches HV 580, which is almost 2.8 times that of the substrate. Compared with the substrate, the alloyed layer has a much smaller displacement and a larger elastic modulus. According to the friction and wear tests at room temperature, the? FeAl?Cr?Nb alloyed layer has lower friction coefficient and less wear mass, implying that the Fe?Al?Cr?Nb alloyed layer can effectively improve the surface hardness and wear resistance of the substrate.
基金supported by the Instrument Development Project of the Chinese Academy of Sciences(No.YZ201539)the National Natural Science Foundation of China(No.21175145)the Shanghai Technical Platform for Testing and Characterization on Inorganic Materials(No.19DZ2290700)。
文摘As a kind of microplasma sustained in air,solution electrode glow discharge(SEGD)ignited between the liquid electrode and metal electrode is attractive to the fields of optical emission spectrometry and mass spectrometry due to its unique advantages,such as low power consumption and low carrier gas consumption.Moreover,the complex and efficient reactions in the liquid phase and plasma phase of SEGD make it considerable research potential in the fields of biology and medicine,material synthesis,electrochemistry.Considering the close relationship between the various fields on SEGD,here we are devoted to provide an overview of the development of SEGD in various fields.More importantly,a systematic discussion on the discharge mechanism is conducted based on the research process in various fields for getting deeper insight into the SEGD.
基金supported by National Natural Science Foundation of China(Nos.11205044 and 11405042)Hebei Natural Science Fund of China(Nos.A2012201015 and A2011201006)+2 种基金the Research Foundation of Education Bureau of Hebei Province of China(No.Y2012009)the Postdoctoral Science Foundation of Hebei Province of China(No.B2014003004)the Postdoctoral Foundation of Hebei University
文摘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.
文摘Through the study of the thermoluminescence(TL) of BaFClxBr1-x: Sm(0<x<1) system, it is found that former assignment of the glow peaks of BaFX(X = Cl, Br) is plausible. Through detailed study by several methods and techniques, a correct assignment is given in this paper, i.e. the first, second, and third glow peaks of BaFClxBr1-xSm are assigned to F(F-), F(Cl-), F(Br-) centers respectively, and the first andsecond glow peaks of BaFX are assigned to F(F-) and F(X-) centers respectively. This results are confirmed by theoretical consideration. Possible reasons for former plausible assignment are also pointed out here.
基金supported by the National Natural Science Foundation of China (Nos.50177002,10475014)
文摘Resistance and capacity-coupled glow discharge （RCCGD） is a new method to produce atmospheric pressure glow discharge in air. In RCCGD, each electrode is connected with both a resistor R and a capacitor C. The R and C can provide a negative feedback to prevent the transition from glow to spark discharge. The influence of coupled resistance, coupled capacity, inter-electrode gap and power source frequency on the discharge is studied and discussed.
文摘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.
基金supported by National Natural Science Foundation of China （No. 50877005）, the National Science Foundation for Distinguished Young Scholars of China （No. 2010DFA61470） and the Project of International Scientific and Technological Cooperation of China （No. 61025001）
文摘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.
基金supported by National Natural Science Foundation of China(50872055/E020703)Funding for Outstanding Doctoral Dissertation in NUAA(BCXJ11-09)+1 种基金the Fundamental Research Funds for the Central UniversitiesFunding of Jiangsu Innovation Program for Graduate Education of China(CXLX110207)
文摘Double glow plasma technique has a high deposition rate for preparing iridium coating. However, the glow plasma can influence the structure of the coating at the single substrate edge. In this study, the iridium coating was prepared by double glow plasma on the surface of single niobium substrate. The microstructure of iridium coating at the substrate edge was observed by scanning electron microscopy. The composition of the coating was confirmed by energy dispersive spectroscopy and X-ray diffraction. There was a boundary between the coating and the substrate edge. The covered area for the iridium coating at the substrate edge became fewer and fewer from the inner area to the outer flange-area. The bamboo sprout-like particles on the surface of the substrate edge were composed of elemental niobium. The substrate edge was composed of the Nb coating and there was a transition zone between the Ir coating and the Nb coating. The interesting phenomenon of the substrate edge could be attributed to the effects of the bias voltages and the plasma cloud in the deposition chamber. The substrate edge effect could be mitigated or eliminated by adding lots of small niobium plates around the substrate in a deposition process.
基金The project partially supported by the Project of Key Science and Technology of Education Ministry (00250), the Natural ScienceFoundation of Gansu Province (3ZS041-A25-028), and the Project of KJCXGC-01, NWNU, China
文摘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,
基金supported by the National Natural Science Foundation of China (No. 50872055/E020703)the Fundamental Research Funds for the Central Universities+1 种基金the Funding for Outstanding Doctoral Dissertation in NUAA (No. BCXJ11-09)the Funding of Jiangsu Innovation Program for Graduate Education (No. CXLX11 0207)
文摘Oxidation resistance coatings of Ir-40 at.% Zr and Ir were produced onto Mo substrates by double glow plasma technology. The oxidation resistances of the coatings were evaluated at high temperature. Ir-Zr coating consisted of two layers： the primary layer close to the substrate was composed of dense columnar grains and the second layer was composed of dense grains of nanometric size. The mass gain of Ir coating above 800℃ was about 1.35% due to the formation of solid IrO2. The mass loss of Ir coating was about 5.3% due to the formation of gaseous oxide IrO3 when being held at 1227 ℃ for 30 min. The substrate was protected more effectively by multilayer than monolayer coating of Ir in oxidizing environment. The Ir-Zr coating was well bonded to the substrate after oxidation at 800℃. After oxidation at 1000℃, the Ir-Zr coating was poorly bonded to the substrate. The oxidation resistance of Ir-Zr coating was poor due to high content of Zr.
文摘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
基金supported by the National Natural Science Foundation of China(No.50872055/E020703)the Fundamental Research Funds for the Central Universities+1 种基金the Funding for Outstanding Doctoral Dissertation in NUAA(No.BCXJ11-09)the Funding of Jiangsu Innovation Program for Graduate Education(No.CXLX110207)
文摘Pure Ir coating was produced by double nism of the Ir coating was investigated. glow plasma technology. Growth mecha- The Ir coating was composed of irregular compacted columnar grains with lots of nanovoids appeared on the interface between the coating and the substrate. The Ir coating was polycrystalline with a preferred （220） orientation due to the initial nuclei with preferred growth on the surface of the substrate. The formation mechanism of the Ir coating depended on kinetic adsorp- tion and diffusion process with nucleation, coalescence and thickness growth. At the beginning of the deposition process, the growth mode of the coating was mainly con- trolled by the nucleation rate. Due to the low substrate temperature resulting in low mobility of the deposited atoms, some micropores and nanoviods were present at the interface. With the deposition process, the substrate temperature was increased and then kept steady. The growth of the coating was governed by the growth rate. The high substrate temperature supported enough energy to surface mobilitv of adatoms.
基金support from "Open Research Center" Projects for Private Universities:matching fund subsidy from Ministry of Education,Culture,Sports,Science and Technology,2007-2011
文摘Exhaustive mineralization of pentachlorophenolate ion（PCP） in phosphate buffer was carried out using anodic contact glow discharge electrolysis（CGDE）,in which plasma was sustained between the electrolyte and anode.During CGDE,PCP degraded smoothly.The amount of total organic carbon decreased significantly,indicating the eventual conversion of the carbon atoms of benzene nucleus to inorganic carbons.Furthermore,chlorine atoms in PCP were liberated as chloride ions.As a primary intermediate product,2,3,5,6tetrachloro-1,4-benzoquinone was detected,and oxalate and formate as byproducts were also found.It was revealed that disappearance of PCP obeyed first-order kinetics.The reaction rate was generally unaffected by both O2 and inert gases in the cell,although it decreased by raising initial pH of solution.In addition,a plausible reaction pathway involving hydroxyl radical was proposed.
基金supported by National Natural Science Foundation of China (No. 10475060)
文摘A novel plasma atmospheric pressure abnormal glow discharge was used to investigate synthesis gas production from reforming methane and carbon dioxide. Special attentions were paid to the discharge characteristics and CH4, CO2 conversion, H2, CO selectivity, and ratio of H2/CO varied with the changing of discharging power, the total flux, and the ratio of CH4/CO2. Experiments were performed in wider operation variables, the discharging power of 240 to 600 W, the CH4/CO2 of 0.2 to 1.0 and the total flux of 140 to 500mL/min. The experiments showed that the conversion of CH4 and CO2 was up to 91.9% and 83.2%, the selectivity of CO and H2 was also up to 80% and 90% and H2/CO mole ratio was 0.2 to 1.2, respectively. A brief analysis for discharge characteristics and the experimental results were given.
基金supported the by Project of Key Science and Technology of Education Ministry (20050)the Natural Science Foundation of Gansu Province (3ZS041-A25-028)the Invention Project of Science & Technology (KJCXGC-01, NWNU), China
文摘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.
文摘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.
基金Project(21275162)supported by the National Natural Science Foundation of ChinaProject(KJZH14217)supported by the Achievement Transfer Program of Institutions of Higher Education in Chongqing,ChinaProject(KJ1601224)supported by the Scientific and Technological Research Program of Chongqing Municipal Education Commission,China
文摘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.
