[Analysis of Carbon Emissions and Influencing Factors in China Based on City Scale].

Assessing regional carbon emissions and their relationship with socio-economic conditions is very important for developing strategies for carbon emission reduction. This study explored the impact of the proportion of non-fossil energy, the land development degree, the urbanization rate of permanent residents, the proportion of secondary industry, per capita GDP, and per capita construction land area on per capita CO2 emissions in 339 prefecture-level and above cities in China (excluding some cities in Xinjiang, Hong Kong, Macao, and Taiwan). A Bayesian belief network modeling carbon emissions was constructed to identify the global effects of various factors on per capita CO2 emissions, and multiscale geographically weighted regression was used to analyze their local effects. The results showed that first, per capita CO2 emissions of cities in China increased from the south to the north and decreased from the eastern coast to the inland region. Second, globally, the sensitivity of per capita CO2 emissions to various factors from high to low was in the order of per capita construction land area>per capita GDP>urbanization rate of permanent residents>land development degree>proportion of secondary industry>proportion of non-fossil energy. Third, locally, the direction of the spatial relationship between each factor and per capita CO2 emissions was consistent with the global relationship, and there was spatial heterogeneity in the strength of the relationship. Finally, clean energy, decarbonization technologies, saving and intensive use of land, and green living were effective ways to achieve the dual-carbon goal.

[Spectroscopic Study on a Direct-Current Driving Plasma Jet in Argon at Atmospheric Pressure].

With a discharge device in a hollow-needle and plate electrode configurations, an atmospheric pressure uniform plasma plume is generated by DC voltage excitation in the ambient air with argon as working gas. The plasma plume is a pulsed discharge despite a direct current voltage is applied through measurements by optical and electrical methods. In order to explain the formation mechanism of the pulse, spatially resolved signals emitted from the plume were detected. It was found that the plasma plume denoted as the luminous layer propagates (a plasma bullet) from the hollow needle to the plate electrode except for the corona discharge in the vicinity of the hollow needle tip. Optical emission spectroscopy is used to investigate the excited electron temperature of the plasma plume as a function of the applied voltage or the spatial distribution of the excited electron temperature. The results show that the excited electron temperature (about 3 eV) increases with increasing applied voltage. Moreover, it increases with the increasing distance along the gas flow under constant voltage.

[Glow Discharge Characteristics of Hollow Needle-Plate Electrode in Atmospheric Pressure Argon].

Atmosphere pressure uniform plasma has the broad application prospect in the industrial field. Using hollow needle cathode-plate anode device excited by direct-current voltage, a uniform and stable glow discharge is generated at atmospheric pressure in ambient air with argon used as working gas. The influence of the experimental parameters (including gas flow rate and the gas gap width) on discharge has been investigated by optical method. It can be found that a glow-discharge plasma column can bridge the two electrodes. The plasma column is uniform, and no filaments can be discerned. Near the plate electrode, the diameter of the plasma column is largest of all positions. The maximal diameter of the plasma column increases with increasing the discharge current or the gas flow rate. Through electrical method, the voltage-current characteristic has been investigated. It has been found that the discharge voltage decreases with increasing the current which is similar with the characteristic of glow discharge in low pressure. It increases with increasing the gas gap width or the gas flow rate. By analyzing the optical emission spectrum scanning from 330 to 450 nm emitted from the direct-current glow discharge, the molecular vibrational temperature and the intensity ratio of spectral lines I391.4/I337.1 have been investigated as functions of the gas flow rate and gas gap width. Results indicate that both the vibrational temperature and the intensity ratio of spectral lines I391.4/I337.1 decrease with increasing the gas flow rate or the gas gap width. In addition, the molecular vibrational temperature and the intensity ratio of spectral lines I391.4/I337.1 have been investigated in spatial resolution along the direction of gas flow (plasma column axial), and give a qualitative analysis as well. It is found that the vibrational temperature and the average electron energy increase with increasing the distance from the hollow needle cathode. These results are important to the industrial applications of glow discharge.

[Investigation on the Spectral Characteristics of a Plasma Jet in Atmospheric Argon Glow Discharge].

Plasma jet is a kind of important plasma source at atmospheric pressure. In recent years, it becomes an important hot topic in the field of low temperature plasma. In this paper, using a tungsten needle and a tungsten wire mesh, a direct-current excited jet is developed to operate in argon at atmospheric pressure. In the atmospheric pressure argon, the plasma jet can produce a stable plasma plume. By using the method of emission spectroscopy, the parameters of the plasma plume are investigated. The discharge emits dazzling white light from the area between the tungsten needle electrode and the wire mesh electrode. A plasma plume with a flame shape appears outside the tungsten wire mesh electrode. For a constant value of voltage (U = 13.5 kV), the length of the plasma plume increases with the gas flow rate. For a constant value of the gas flow rate(10 L · min⁻¹), the length of the plasma plume increases with the voltage. The voltage is inversely proportional to the current under the constant gas flow rate. In other words, the voltage decreases with the discharge current, which indicates that a glow discharge is formed in the plasma jet. Optical emission spectrum in 300 to 800 nm is collected from the direct-current excited plasma jet. By Boltzmann plot method, the excited electron temperature of the plasma plume is investigated as a function of the applied voltage or the gas flow rate. Results show that the excited electron temperature increases with decreasing applied voltage under the constant gas flow. Moreover, it increases with decreasing the gas flow under the constant voltage. Based on the discharge theory, these experimental phenomena are explained qualitatively. These results are of great importance to the development of atmospheric pressure uniform discharge plasma source and its application in industrial field.

Lovastatin-Induced Phosphatidylinositol-4-Phosphate 5-Kinase Diffusion from Microvilli Stimulates ROMK Channels.

We recently showed that lovastatin attenuates cyclosporin A (CsA)-induced damage of cortical collecting duct (CCD) principal cells by reducing intracellular cholesterol. Previous studies showed that, in cell expression models or artificial membranes, exogenous cholesterol directly inhibits inward rectifier potassium channels, including Kir1.1 (Kcnj1; the gene locus for renal outer medullary K(+) [ROMK1] channels). Therefore, we hypothesized that lovastatin might stimulate ROMK1 by reducing cholesterol in CCD cells. Western blots showed that mpkCCDc14 cells express ROMK1 channels with molecular masses that approximate the molecular masses of ROMK1 in renal tubules detected before and after treatment with DTT. Confocal microscopy showed that ROMK1 channels were not in the microvilli, where cholesterol-rich lipid rafts are located, but rather, the planar regions of the apical membrane of mpkCCDc14 cells. Furthermore, phosphatidylinositol-4,5-bisphosphate [PI(4,5)P2], an activator of ROMK channels, was detected mainly in the microvilli under resting conditions along with the kinase responsible for PI(4,5)P2 synthesis, phosphatidylinositol-4-phosphate 5-kinase, type I γ [PI(4)P5K I γ], which may explain the low basal open probability and increased sensitivity to tetraethylammonium observed here for this channel. Notably, lovastatin induced PI(4)P5K I γ diffusion into planar regions and elevated PI(4,5)P2 and ROMK1 open probability in these regions through a cholesterol-associated mechanism. However, exogenous cholesterol alone did not induce these effects. These results suggest that lovastatin stimulates ROMK1 channels, at least in part, by inducing PI(4,5)P2 synthesis in planar regions of the renal CCD cell apical membrane, suggesting that lovastatin could reduce cyclosporin-induced nephropathy and associated hyperkalemia.

[Investigation of a jet operated in atmospheric pressure argon by optical emission spectroscopy].

A uniform plasma plume was generated in a coaxial dielectric barrier discharge jet through blowing argon into the ambient air at atmospheric pressure. The plasma plume was uniform along the direction of the gas flow. The length of the plasma plume was investigated as a function of the peak voltage, the driving frequency and the gas flow rate. It was found that with increasing the gas flow rate, the plume length increases when the flow rate is lower than 4 L x min(-1), and decreases when it is higher than 4 L x mic(-1). Under constant gas flow rate, the length of the plasma plume increases with the increase in the peak value of the applied voltage and the driving frequency. According to the discharge theory and based on the analysis of the turbulence and the advection, a qualitative explanation was given for the variance of plume length as functions of the experimental parameters. Results also show that there is a discharge pulse for the plasma plume in every positive half cycle, while there is no pulse in negative half cycle. The coaxial dielectric barrier discharge shows two pulses in every positive half cycle and a pulse in every negative half cycle. Analyzing these experimental phenomena mentioned above, a formation mechanism of the plasma plume was proposed. The optical emission spectra were obtained for both the coaxial dielectric barrier discharge and the plasma plume. There was no apparent difference except that some emission lines from reactive species such as OH and N2 were found in the plasma plume. Using the first negative band of, the rational temperature of the plasma plume was measured. Results show that the rational temperature of the plasma plume decreases away from the jet nozzle, and increases with increasing the peak value of the applied voltage.

[Spectroscopic characteristics of DC excited atmospheric pressure glow discharges generated in a needle-plate electrode device and a needle-water electrode one].

Glow discharge characteristics in two discharge devices, i.e. in a needle-plate electrode geometry and a needle-water electrode one were compared by using spectroscopic method. Results show that the different emission regions were found in both discharges generated by the two devices. From the cathode to the anode, there are a cathode glow region, cathode dark glow, a positive column, and an anode glow region. The anode dark region can be clearly discerned in the glow discharge in the needle-plate electrode device, while it almost cannot be found in the needle-water electrode discharge. Comparing the current-voltage characteristics of the two glow discharges, it was found that the voltage across the electrodes decreases with increasing the discharge current in both discharge devices, while the voltage in the needle-water glow discharge is higher than that of the needle-plate one at the same current value. The current-voltage curves have a negative slope and their current densities lie in the range from 10-5 to 10-4 A? cm-2, which indicates that a normal glow discharge mechanism was involved in the two discharges. Comparing the optical spectra scanning from 300nm to 800nm and emitted from the whole normal glow discharge in the two electrode devices, similar spectral lines from the two discharges can be found on the optical emission spectrum, including the second positive system of nitrogen molecules (337.1nm) and the first negative system of nitrogen molecular ions (391.4nm). However, the intensity ratio of spectral lines is different. The intensity ratio (391.4nm to 337.1nm) and vibrational temperature were investigated at different locations. It was found that the intensity ratio of the needle-water electrode discharge is larger than that of the needle-plate electrode discharge at the same location. Furthermore, the vibrational temperature in the needle-water electrode discharge is higher than that of the needle-plate one at the same location.

[Vibrational temperature of plasma plume in atmospheric pressure air].

A tri-electrode discharge device was designed in a dielectric barrier discharge configurations to generate a fairly large volume plasma plume in atmospheric pressure air. The discharge characteristics of the plasma plume were investigated by an optical method. The discharge emission from the plasma plume was collected by a photomultiplier tube. It was found that the number of discharge pulse per cycle of the applied voltage increased with increasing the peak value of the applied voltage. The emission spectra of the plasma plume were collected by a spectrometer. The vibrational temperature was calculated by fitting the experimental data to the theoretical one. Results showed that the vibrational temperature of the plasma plume decreases with increasing the U(p). Spatially resolved measurement of the vibrational temperature was also conducted on the plasma plume with the same method. Results showed that the vibrational temperature increases firstly and then decreases with increasing distance from the nozzle. The vibrational temperature reachs its maximum when the distance is 5.4 mm from the nozzle. These experimental phenomena were analyzed qualitatively based on the discharge theory. These results have important significance for the industrial applications of the plasma plume in atmospheric pressure air.

[Measurement of active particles generated in a coaxial barrier discharge by spectral method].

Coaxial dielectric barrier discharge has extensive application prospects. A dielectric barrier discharge device with water electrode was used to investigate the discharge properties and spectral intensity emitted from active particles in the air by optical method. Results indicate that the optical emission spectra consist of spectral lines from oxygen atoms (777.5 and 844.6 nm), which implies that oxygen atoms with high chemical activity were generated in the discharge plasma. Through spatially resolved measurements, spectral intensities from oxygen atoms were given as functions of the experimental parameters such as the value of the applied voltage, the gas flow rate and argon content. Results show that the spectral line intensity from oxygen atom increases with increasing the peak value of the applied voltage, increases with increasing the gas flow rate, reaches its maximum with a gas flow rate of 30 L x min(-1) and then decreases with further increasing the gas flow rate. Similarly, the spectral line intensity increases firstly and then decreases with increasing argon content (in a mixture of argon and air) and a maximum is reached when argon content is 16.7%.

[Comparative investigation of the discharge characteristics of a single needle jet and needle-plate jet].

In the present paper, discharge characteristics were studied in atmospheric pressure argon by a single needle jet and needle-plate jet through combination of optical measurement and electrical one. Results show that the length and cross-sectional area of the plasmas generated in the two jets increase with increasing the peak value of the applied voltage. The cross-sectional area generated by needle-plate jet is bigger than that of the single needle jet at the same voltage. A lower inception voltage is needed for the needle-plate jet compared with the single needle jet at the same U(p). Through the spectra emitted from the two jets, electron temperature and vibration temperature wee compared for the plasmas generated by the single needle jet and needle-plate jet, respectively. It can be found that the electron temperature and the vibrational temperature of the two jets increase with increasing U(p). The needle-plate jet has higher values of electron temperature and vibrational temperature than the single needle jet at the same U(p). These results have significant values for the industrial application of the atmospheric pressure plasma jet.

[Experimental investigation of electrical characteristics and vibrational temperature of barrier discharge in flowing argon].

The electrical characteristics and vibrational temperature were investigated as functions of gas gap width, driving frequency and gas flow rate in flowing argon by using a dielectric barrier discharge device with transparent water electrodes. Electrical measurement results show that the discharge with a smaller gas gap width has a higher value of peak current and consumes more power than that with a larger gap width. Both the peak value of discharge current and consumed power increase monotonically with increasing the driving frequency, and decrease with increasing the gas flow rate. Through analyzing the vibrational systems of nitrogen molecule by optical emission spectroscopy, it was found that the vibrational temperature has a similar trend with the peak value of discharge current and consumed power by changing the driving frequency, gas gap width and gas flow rate. These results are important to the industrial applications of atmospheric pressure barrier discharge in flowing gas.

[Spectral investigation of atmospheric pressure plasma column].

Atmospheric pressure plasma column has many important applications in plasma stealth for aircraft. In the present paper, a plasma column with a length of 65 cm was generated in argon at atmospheric pressure by using dielectric barrier discharge device with water electrodes in coaxial configurations. The discharge mechanism of the plasma column was studied by optical method and the result indicates that a moving layer of light emission propagates in the upstream region. The propagation velocity of the plasma bullet is about 0.6 x 10(5) m x s(-1) through optical measurement. Spectral intensity ratios as functions of the applied voltage and driving frequency were also investigated by spectroscopic method. The variation in spectral intensity ratio implies a change in the averaged electron energy. Results show that the averaged electron energy increases with the increase in the applied voltage and the driving frequency. These results have significant values for industrial applications of the atmospheric pressure discharge and have extensive application potentials in stealth for military aircraft.

[Four styles of spectral line shape function and their transformation relation].

Four styles of spectral line shape function and their transformation relation were investigated theoretically. The photon number and energy distribution as functions of frequency and wavelength resulting from Doppler broadening were investigated, and the maximum intensity and FWHM (full width at half maximum intensity) were obtained. The results show that the photon number distribution as function of frequency is almost the same as the energy distribution as function of frequency, while the photon number distribution as function of wavelength is almost the same as the energy distribution as function of wavelength. The method has been presented by analyzing the Doppler spectral line shape function, with which the ratio of density between two spectral lines can be obtained according to the ratio of maximum value of two spectral lines.

[Spectral intensity distribution of oxygen atom in a plasma plume].

Low temperature plasma generated in plasma plume discharge at atmospheric pressure has prosperous application fields in industry because the vacuum device can be dispensable and some complex materials can be treated in three dimensions by this plasma plume. A stable plasma plume was generated in atmospheric pressure air in the present paper by using a plasma needle discharge device. It was found by spectral measurement that there are some spectral lines emitted from oxygen atom such as 777.5 and 844.6 nm in the optical emission spectra of the plasma plume. This phenomenon indicates that oxygen atom with high chemical activity was generated in the air discharge at atmospheric pressure. The spatial distribution of the spectral intensity from the oxygen atom was investigated by spectroscopic method. Results show that the spectral intensity from oxygen atom near the needle electrode was much higher than that in other regions. In order to explain this experimental phenomenon, spatial-resolved signals emitted from the plume were detected by using photomultiplier tubes. It was found that the width of light pulse near the needle electrode was much bigger than that in other regions. These results are important for the application of plasma plume in industry such as sterilization and disinfection fields.

[Investigation of the vibrational temperature and gas temperature in gas discharge generated by plasma needle].

Low temperature plasma generated by plasma needle in atmospheric pressure air has extensive application prospects in industry because the vacuum device can be dispensable. In the present paper a stable plasma plume was generated in air by using a plasma needle device. The vibrational temperature and gas temperature were investigated for the plasma plume by optical spectroscopic method. Research results show that the plasma plume generated in atmospheric pressure air can be distinguished as a strong emission area near the needle followed by a weak emission area. The light emission signal from the discharge is a pulse per half cycle of the applied voltage with a time width of several microseconds. Results also indicate that the vabrational temperature varies from 2 500 to 3 000 K for different emission locations. The vibrational temperature increases with increasing the distance from the needle point in the strong emission area and it reaches a peak value at a distance of about 5mm from the needle point. The vibrational temperature decreases with increasing the distance from the needle. Similarly, the gas temperature decreases from 640K to 540K with increasing the distance from the needle point. These results are of great importance for the industrial applications of air discharge at atmospheric pressure.

[Comparative study on the gas temperature of a plasma jet at atmospheric pressure].

A plasma jet of a dielectric barrier discharge in coaxial electrode was used to produce jet plasma in flowing work gas (argon mixed with trace nitrogen) at atmospheric pressure. The relation between the plasma length and the gas flow rate was obtained by taking the images of the jet plasma. A high-resolution optical spectrometer was used to collect the optical emission spectrum. The emission spectra of the first negative band of N(2+) (B2 Sigma(u+)-->Chi2 Sigma(g+), 390-391.6 nm) were used to estimate the rotational temperature of the plasma plume by fitting the experimental spectra to the simulated spectra. The gas temperature was investigated by this optical method and results show that the gas temperature increases with increasing the applied voltage. For comparison, a thermometer was used to measure the temperature of the gas emitted from the jet. The results also show that the gas temperature increases with increasing the applied voltage. The gas temperatures obtained by the two methods are consistent. The difference was analyzed.

[Investigation on the electron density of a micro-plasma jet operated at atmospheric pressure].

In the present paper, a micro-hollow cathode discharge setup was used to generate micro-plasma jet in flowing mixture of Ar and N2 at atmospheric pressure. The characteristics of the micro-plasma jet were investigated by means of optical method and electrical one. It has been found that breakdown occurs in the gas between the two electrodes when the input power of electric source is increased to a certain value. Plasma appears along the gas flow direction when the mixed gas flows from the aperture of the micro-hollow cathode, and the length of plasma reaches 4 mm. The discharge current is quasi-continuous, and the duration of discharge pulse is about 0.1 micros. Electron density was studied by using Einstein equation and Stark broadening of spectral lines from the emission spectrum respectively. It was found that the results of electron density calculated by the two methods are consistent with the order of 10(15) x cm(-3). It was also found that the electron density is almost independent of power. A qualitative explanation to the phenomenon is given based on the gas discharge theory.

[Investigation on the gas temperature of a plasma jet at atmospheric pressure by emission spectrum].

A plasma jet of a dielectric barrier discharge in coaxial electrode was used to produce plasma plume in atmospheric pressure argon. Spatially and temporally resolved measurement was carried out by photomultiplier tubes. The light emission signals both from the dielectric barrier discharge and from the plasma plume were analyzed. Furthermore, emission spectrum from the plasma plume was collected by high-resolution optical spectrometer. The emission spectra of OH (A 2sigma + --> X2 II, 307.7-308.9 nm) and the first negative band of N2+ (B2 sigma u+ --> X2 IIg+, 390-391.6 nm) were used to estimate the rotational temperature of the plasma plume by fitting the experimental spectra to the simulated spectra. The rotational temperature obtained is about 443 K by fitting the emission spectrum from the OH, and that from the first negative band of N2+ is about 450 K. The rotational temperatures obtained by the two method are consistent within 5% error band. The gas temperature of the plasma plume at atmospheric pressure was obtained because rotational temperature equals to gas temperature approximately in gas discharge at atmospheric pressure. Results show that gas temperature increases with increasing the applied voltage.

[Comparative study on current and light emission for different modes in dielectric barrier discharge].

In the present study, a device of water electrodes was used to get different discharge modes in air and Ar respectively, including stochastic filament mode, hexagon pattern mode and homogeneous diffusion mode. By comparing the waveforms of light emission and current for the three different modes, the relationship between the waveforms of light emission and current in dielectric barrier discharge was investigated. Research results show that the waveforms of light emission and current are similar when the discharge signal is very strong. However, the discharge current signal can not be discerned from the displacement current when the discharge current is very weak, because the current signal includes discharge current and displacement current. Under this circumstance, discharge dynamics can be investigated by studying the waveform of light emission. In addition, the light emission signal of single filament was obtained because spatial resolved measurement can be easily realized for the light emission signal measurement. Consequently, the research results indicate that it is a good method to investigate the discharge dynamics by analyzing the waveform of light emission in dielectric barrier discharge.

[Spectral characteristics of different discharge modes in air dielectric barrier discharge].

The electron energy in the transition from streamer discharge to glow-like discharge in dielectric barrier discharge in air was investigated by using emission spectra. The vibrational temperature was measured with the N2 second positive band (C3II(u) --> B3II(g)) of the emission spectrum. The average electron energy was investigated from the relative intensity of the nitrogen molecular ion line at 391.4 nm and the nitrogen molecular line at 337.1 nm. It was found that the vibrational temperature and the relative intensity of nitrogen molecular ion line at 391.4 nm increased abruptly in the transition from streamer discharge to glow-like discharge. It was also found that the pressure for the transition pressure from streamer discharge to glow-like discharge changed with different gap distances, but the product of the transition pressure and gas gap width remained constant.