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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.
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Objective: To investigate the relationship between nutritional risk status and clinical outcome in children with tuberculous meningitis (TBM). Methods: The clinical data (basic information, clinical symptoms and laboratory test results) of 112 patients with TBM, who were admitted to Department of Pediatric Infectious Diseases of West China Second Hospital of Sichuan University,from January 2013 to December 2020 were retrospectively analyzed. The patients were divided into the nutritional risk group and the non-nutritional risk group according to the assessment of the nutritional risk by the STRONGkids Scale. The variables of basic information, clinical symptoms and laboratory test measurements etc. were compared between the two groups by using Student t test, Rank sum test or Chi-square test. Multivariate Logistic regression analysis were used to analyze nutritional risk factors. Results: Among 112 patient with TBM, 55 were males and 57 females. There were 62 cases in the nutritional risk group and 50 cases in the non-nutritional risk group. The proportion of cases with nutritional risk was 55.4% (62/112). Patients in the nutritional risk who lived in rural areas, had symptoms of brain nerve damage, convulsions, emaciation and anorexia, with a diagnosis time of ≥21 days, and the level of cerebrospinal fluid (CSF) protein were all higher than those in the non-nutritional risk group ((50 cases (80.6%) vs. 32 cases (64.0%), 20 cases (32.3%) vs.8 cases (16.0%), 33 cases (53.2%) vs. 15 cases (30.0%), 30 cases (48.4%) vs. 2 cases (4.0%), 59 cases (95.2%) vs. 1 case (2.0%),41 cases (66.1%) vs.18 cases (36.0%), 1 406 (1 079, 2 068) vs. 929 (683, 1 208) mg/L, χ2=3.91, 3.90, 6.10, 26.72, 98.58, 10.08, Z=4.35, all P<0.05). The levels of serum albumin,hemoglobin,lymphocyte count, white blood cell count, and CSF glucose were significantly lower in patients with nutritional risk ((36±5) vs. (41±4) g/L, (110±17) vs. (122±14) g/L, 1.4 (1.0, 2.0)vs. 2.3 (1.6, 3.8)×109/L, 7.8 (6.3, 10.0)×109 vs. 10.0 (8.3, 12.8)×109/L, 1.0 (0.8, 1.6) vs. 2.1 (1.3, 2.5) mmol/L, t=-6.15, -4.22, Z=-4.86, -3.92, -4.16, all P<0.05).Increased levels of serum albumin (OR=0.812, 95%CI:0.705-0.935, P=0.004) and lymphocyte count (OR=0.609, 95%CI:0.383-0.970, P=0.037) may reduce the nutritional risk of children with TBM; while convulsions (OR=3.853, 95%CI:1.116-13.308, P=0.033) and increased level of CSF protein (OR=1.001,95%CI:1.000-1.002, P=0.015) may increase the nutritional risk of children with TBM. Similarly, the rate of complications and drug-induced liver injury was higher in the nutritional risk group (47 cases (75.8%) vs. 15 cases(30.0%), 31 cases (50.0%) vs.8 cases (16.0%), χ2=23.50, 14.10, all P<0.05). Moreover, the length of hospital stay was also longer in the nutritional risk group ((27±13) vs. (18±7) d, t=4.38, P<0.05). Conclusions: Children with TBM have a high incidence of nutritional risk. Convulsive, the level of serum albumin, the level of lymphocyte count and CSF protein may affect the nutritional risk of children with TBM. The nutritional risk group has a high incidence of complications and heavy economic burden.It is necessary to carry out nutritional screening and nutritional support for children with TBM as early as possible.
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Femenino , Humanos , Masculino , Recuento de Leucocitos , Evaluación Nutricional , Estado Nutricional , Estudios Retrospectivos , Tuberculosis Meníngea/diagnósticoRESUMEN
BACKGROUND@#More and more scholars have called for the cumulative live birth rate (CLBR) of a complete ovarian stimulation cycle as a key indicator for assisted reproductive technology. This research aims to study the CLBR of the first ovarian hyperstimulation cycles and analyze the related prognosis factors that might affect the CLBR.@*METHODS@#Our retrospective study included first in vitro fertilization or intracytoplasmic sperm injection (IVF/ICSI) cycles performed between January 2013 to December 2014. A total of 17,978 couples of first ovarian hyperstimulation IVF/ICSI cycles were included. The study was followed up for 4 years to observe the CLBR. The multivariable logistic regression model was used to analyze the prognosis factor, P value of <0.05 was considered statistically significant.@*RESULTS@#The cumulative pregnancy rate was 58.14% (10,452/17,978), and the CLBR was 49.66% (8928/17,978). The female age was younger in the live birth group when compared with the non-live birth group (30.81 ± 4.05 vs. 33.09 ± 5.13, P < 0.001). The average duration of infertility was shorter than the non-live birth cohort (4.22 ± 3.11 vs. 5.06 ± 4.08, P < 0.001). The preliminary gonadotropin used and the total number of gonadotropin used were lower in the live birth group when compared with the non-live birth group (both P < 0.001). Meanwhile, the number of oocytes retrieved and transferrable embryos were both significantly higher in the live birth group (15.35 ± 7.98 vs. 11.35 ± 7.60, P < 0.001; 6.66 ± 5.19 vs. 3.62 ± 3.51, P < 0.001, respectively).@*CONCLUSIONS@#The women's age, body mass index, duration of infertility years, infertility factors, controlled ovarian hyperstimulation protocol, the number of acquired oocytes, and number of transferrable embryos are the prognosis factors that significantly affected the CLBR.
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Femenino , Humanos , Embarazo , Tasa de Natalidad , China , Fertilización In Vitro , Nacimiento Vivo , Inducción de la Ovulación , Índice de Embarazo , Estudios Retrospectivos , Inyecciones de Esperma IntracitoplasmáticasRESUMEN
Objective@#Prior pulmonary tuberculosis (PTB) on chest X-ray (CXR) was commonly found in infertile patients receiving examinations before @*Method@#We conducted a retrospective cohort study of 14,254 infertile patients who had received IVF-ET at Peking University Third Hospital in 2017. Prior PTB was defined as the presence of signs suggestive of old or inactive PTB on CXR, with or without a clinical TB history. Patients who had prior PTB on CXR but had not received a clinical diagnosis and anti-TB therapy were included for analysis. Live birth, clinical pregnancy, and miscarriage rates were compared between the untreated PTB and non-PTB groups.@*Results@#The untreated PTB group had significantly lower clinical pregnancy (31.7% @*Conclusions@#Untreated PTB was associated with adverse pregnancy outcomes after IVF-ET, especially in patients with unexplained infertility, highlighting the clinical significance of PTB in this specific patient population.
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Adulto , Femenino , Humanos , Persona de Mediana Edad , Embarazo , Adulto Joven , Aborto Espontáneo/epidemiología , China/epidemiología , Transferencia de Embrión/estadística & datos numéricos , Fertilización In Vitro/estadística & datos numéricos , Infertilidad Femenina/etiología , Nacimiento Vivo/epidemiología , Complicaciones Infecciosas del Embarazo/epidemiología , Resultado del Embarazo/epidemiología , Radiografía Torácica , Estudios Retrospectivos , Tuberculosis Pulmonar/epidemiologíaRESUMEN
When this paper was first published the following ethical statement was omitted in error: The research was approved by the Ethics Committee of Experimental Animal Management of Institute of Special Wild Economic Animals and Plants, Chinese Academy of Agriculture Sciences (No. 201807024). All animals were treated in strict accordance with animal ethics procedures and norms. The authors would like to apologise for any inconvenience caused.
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To investigate the effect of ginseng neutral polysaccharide on gut microbiota composition and diversity as well as the therapeutic effect for antibiotic associated diarrhea( AAD) in mice. The water-soluble ginseng neutral polysaccharide( WGPN) was purified from water-soluble ginseng polysaccharides( WGP) by DEAE-sepharose fast flow column,which was obtained from the roots of Panax ginseng. AAD mice were induced by gastric gavage with lincomycin hydrochloride,followed by administration of normal saline( natural recovery group,NR) or WGPN( WGPN group) for one week. Body weight changes,psychosis and diarrhea status were observed and assessed. 12 h after the last administration,histological observation of ileum and 16 S rRNA high throughput sequencing analysis of intestinal contents were conducted to identify the effects of WGPN on AAD mice. The results showed that WGPN could alleviate the symptoms of diarrhea in mice,decrease the inflammation and edema of ileum,and increase the length of intestinal villi. As compared to NR mice,WGPN could increase the relative abundance of Lactobacillus,and significantly decrease the relative abundance of Bacteroides,Streptococcus,Ochrobactrum and Pseudomonas at the genus level. In conclusion,WGPN could improve the gut microecology by recovering the ileum structure and improving the diversity and composition of the gut microbiota in AAD mice.
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Animales , Ratones , Antibacterianos , Diarrea , Microbioma Gastrointestinal , Panax , PolisacáridosRESUMEN
<p><b>Background</b>Luteal support is a key to patients undergoing in vitro fertilization and embryo transfer (IVF-ET) with gonadotropin-releasing hormone (GnRH)-antagonist protocol. This study aimed to compare the effect between vaginal progesterone (VP) and intramuscular progesterone (IMP) with GnRH-antagonist protocol after IVF-ET.</p><p><b>Methods</b>A total of 1760 patients (18 years ≤ age ≤35 years) undergoing IVF-ET with GnRH-antagonist protocol were studied retrospectively between September 2014 and August 2015 in Peking University Third Hospital. In the patients, 1341 patients received VP (VP group) and 419 patients received IMP (IMP group) as luteal support. We compared clinical outcomes between these two groups. The primary objective of the study was the live birth rate. Measurement data between the two groups were conducted using independent samples t-test. The variables in line with non-normal distribution were expressed as median (p25 and p75) and were compared using nonparametric Mann-Whitney U-test.</p><p><b>Results</b>Live birth rate in VP group was 38.55%, significantly higher than that in the IMP group, which was 30.79% (χ = 8.287, P = 0.004). The clinical intrauterine pregnancy rate and implantation rate in VP group were also significantly higher than those in the IMP group (clinical intrauterine pregnancy rate 47.35% vs. 41.29%, χ = 4.727, P = 0.030; implantation rate 30.99% vs. 25.26%, χ = 14.546, P < 0.001). Any statistically significant differences in ectopic pregnancy and abortion rates between two groups were not observed.</p><p><b>Conclusion</b>: Luteal support with VP had better clinical outcomes for young women undergoing IVF-ET with GnRH-antagonist protocol.</p>
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Objective:To observe the expression of IL-35 in chronic sinusitis with nasal polyps(CRSwNP),and to complement the pathogenesis.Methods:The clinical data and nasal polyp tissues of CRSwNP who were hospitalized from May 2016 to April 2017 were randomly selected.The subjective symptoms were scored by visual analogue scale (VAS),the nasal endoscopy score by Lanza-Kennedy,and the CT score by Lund-Mackay.The IL-35 mRNA were detected by Real-time PCR in nasal polyp tissues,while the IL-35, IL-17 and IL-10 were detected by ELISA.Results: A total of 51 patients of the clinical data and nasal polyp tissues were collected.Among them,30 males and 21 females had the mean age of (43.3 ± 15.1) years,the VAS score was (5.5 ± 1.7),the Endoscopy score was(6.4±2.0),the CT score was(11.7±3.8).Our results of Real-time PCR and ELISA analysis showed that IL-35 mRNA and protein expression was significantly decreased in CRSwNP compared with normal nasal mucosa (P<0.05).But IL-17 and IL-10 were significantly increased by ELISA in CRSwNP compared with normal nasal mucosa (P<0.05).Conclusion: These data suggest that IL-35 may play an important role in the development and progression of CRSwNP.
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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.
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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.
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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⻹), 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.
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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.
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Colesterol/metabolismo , Túbulos Renales Colectores/metabolismo , Lovastatina/farmacología , Microvellosidades/metabolismo , Canales de Potasio de Rectificación Interna/metabolismo , Análisis de Varianza , Animales , Western Blotting , Membrana Celular/metabolismo , Células Cultivadas , Ciclosporinas/metabolismo , Regulación de la Expresión Génica , Túbulos Renales Colectores/efectos de los fármacos , Ratones , Microscopía Confocal , Microvellosidades/efectos de los fármacos , Microvellosidades/ultraestructura , Modelos Animales , Canales de Potasio de Rectificación Interna/efectos de los fármacos , Canales de Potasio de Rectificación Interna/genética , ARN Interferente Pequeño/metabolismo , Reacción en Cadena en Tiempo Real de la Polimerasa/métodos , Valores de Referencia , Sensibilidad y Especificidad , Transducción de SeñalRESUMEN
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.
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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.
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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.
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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%.
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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.
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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.
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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.
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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.