共查询到20条相似文献,搜索用时 9 毫秒
1.
Jie Li Yan Wu Ninghui Wang Guofeng Li Qiunan Huang 《IEEE transactions on plasma science. IEEE Nuclear and Plasma Sciences Society》2003,31(3):333-337
The flow rate of flue gas in the industrial experiments was 3000 Nm/sup 3//h. The flue gas from the boiler burning coal was used. The influences of operating parameters on the efficiency of desulfuration (DeSO/sub 2/) were studied, which include the retention period of flue gas in the reactor, the initial concentration of SO/sub 2/ in flue gas, a mole ratio of NH/sub 3/ to SO/sub 2/ in the gas, the temperature of the gas, as well as the power consumption of pulsed corona discharges. The experimental results shown that the efficiency of DeSO/sub 2/ was above 80%, when the initial concentration of SO/sub 2/ was 1000 /spl sim/ 2000 ppm, the gas temperature was 60 /spl deg/C /spl sim/ 75 /spl deg/C, the retention period was more than 5.8 s, a mole ratio of NH/sub 3/ to SO/sub 2/ was 2 : 1, the water content in flue gas was above 6%, and he consumption was 2.5 /spl sim/ 3.5 Wh/Nm/sup 3/. 相似文献
2.
Water vapor fluorescence in air induced by femtosecond laser filaments was systematically investigated. The fluorescence signal intensity was found to be linearly proportional to the water vapor concentration, which opens up the possibility of absolute humidity measurements, even remotely. 相似文献
3.
Jong-Uk Kim Yeonkyu Ko 《IEEE transactions on plasma science. IEEE Nuclear and Plasma Sciences Society》2001,29(4):649-652
A relatively new process, electrothermal-chemical (ETC) synthesis, is proposed and tested for synthesizing nanocrystalline aluminum nitride (AlN) and aluminum powders. The ETC synthesis employed a plasma gun especially adapted for material synthesis. The plasma gun is powered by high magnitude current pulse (100 kA flowing for 1.2 ms) and produces pulsed, high-velocity metal vapor plasma jets. The pulsed plasma jet is directed into a reaction chamber which is filled with room temperature atmospheric pressure nitrogen (N2) or helium (He) gas reacting with the metal vapor plasma jet. Transmission electron microscopy and X-ray diffraction have been applied to characterize the synthesized materials and confirmed that the material contained nanocrystalline aluminum (Al) and AlN whose particle size ranging 30-120 nm 相似文献
4.
《低温与超导》2015,(6)
搭建了高效利用室外环境空气冷能的分离式热管与蒸气压缩式复合机房空调系统实验台,对系统在热管工况和蒸气压缩式工况的性能进行了实验研究。结果表明:复合空调系统在热管工况下换热量随换热温差、高差、风量的增大而增大;当换热温差进风温差从11.6℃增加到17.4℃,换热量增加了14.4%;风量由2937.4m3/h增加到4196.3m3/h,换热量增加了5.4%;高差由1.1m增大到2.0m,换热量增加了8.3%;该系统的最佳制冷剂充注量为5.4kg。该系统在蒸气压缩式制冷工况下也具有良好的运行效果,且可实现两种模式的灵活切换,表明该复合空调系统是一种的高效可靠机房空调系统。 相似文献
5.
N. Matsuki Y. Abiko M. Kobayashi K. Miyazaki H. Fujioka H. Koinuma 《Applied Physics A: Materials Science & Processing》2004,79(4-6):1413-1416
In electronic device fabrication, we frequently encounter the situations to deposit thin films of semiconductors, ceramics, and metals sequentially. Since the appropriate methods for depositing these films are frequently different, it should be beneficial for the research of new devices to develop a system that enables the depositions of different films not only sequentially but also in parallel by the procedure as prescribed. In this paper, we report on a tandem system composed of a pulsed laser deposition (PLD) and two plasma chemical vapor deposition (PCVD) chambers and its application in the fabrication of a prototype structure directed towards the field effect a-Si:H solar cell. PLD and PCVD were used to deposit conductive and semiconductive/insulative film layers, respectively. An exchangeable masking scheme was designed and installed in the system so we could make several device structures in parallel and quickly optimize the device and process parameters by the combinatorial methodology. PACS 81.15.Fg; 81.15.Gh; 85.30.-z; 85.30.Tv; 85.60.-q 相似文献
6.
Chun Jiang Yu Fei Xu Zhong Yang Luo Wei Cao Bo Wei Xiang Gao Meng Xiang Fang Ke Fa Cen 《Journal of Electrostatics》2009,67(6):829-834
The NO and SO2 gas conversion processes in a pulsed corona discharge field have been studied. The experiments were conducted to investigate the influences of water vapor and fly ash addition on the conversion efficiencies of NO and SO2. Experimental results show that positive pulsed corona discharge can facilitate NO and SO2 conversion processes, and the conversion efficiencies of NO and SO2 are primarily dependent on the radicals OH, O and the active species O3, HO2, H2O2, etc. With water vapor addition, SO2 conversion efficiency is improved, but NO conversion process is restrained. Low fly ash concentration helps to enhance the conversion of NO and SO2; however, the conversion efficiencies of NO and SO2 are drastically degraded by high fly ash concentration addition. The synergistic effects of water vapor and fly ash addition strengthen the chemical adsorption ability of the fly ash surface, which results in a considerable improvement in the conversion of NO and SO2. Furthermore, the specific input energy plays an important role in NO and SO2 conversion efficiencies. Measured conversion efficiencies of NO and SO2 reach about 60% and 90%, respectively, under the conditions tested. 相似文献
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8.
Growth and characterization of AlN epilayers using pulsed metal organic chemical vapor deposition
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We report the growth of Al N epilayers on c-plane sapphire substrates by pulsed metal organic chemical vapor deposition(MOCVD). The sources of trimethylaluminium(TMAl) and ammonia were pulse introduced into the reactor to avoid the occurrence of the parasitic reaction. Through adjusting the duty cycle ratio of TMAl to ammonia from 0.8 to 3.0, the growth rate of Al N epilayers could be controlled in the range of 0.24 m/h to 0.93 m/h. The high-resolution x-ray diffraction(HRXRD) measurement showed that the full width at half maximum(FWHM) of the(0002) and(10-12) reflections for a sample would be 194 arcsec and 421 arcsec, respectively. The step-flow growth mode was observed in the sample with the atomic level flat surface steps, in which a root-mean-square(RMS) roughness was lower to 0.2 nm as tested by atomic force microscope(AFM). The growth process of Al N epilayers was discussed in terms of crystalline quality, surface morphology,and residual stress. 相似文献
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10.
Positive corona discharge in inert gas mixtures with impurities of water vapor and air in small amounts at pressures of 100–300
kPa is studied. Experiments are carried out on a scale model with a system of gas mixture-pumping of the “electric wind” type.
Uzhgorod State University, 46, Pidgirna St., Uzhgorod, 294000, Ukraine. Translated from Zhurnal Prikladnoi Spektroskopii,
Vol. 64, No. 2, pp. 242–248, March–April, 1997. 相似文献
11.
介绍了空调用压缩机的建模方法,选用合适的性能参数并采用MATLAB软件进行建模仿真,获得了良好的效果,为空调用压缩机的进一步仿真优化与结构设计提供参考价值。 相似文献
12.
Dong-Joo Kim Kyo-Seon Kim 《IEEE transactions on plasma science. IEEE Nuclear and Plasma Sciences Society》2003,31(2):227-235
The particle formation and growth combined with plasma chemistry in the pulsed corona discharge process (PCDP) to remove NO/sub x/ were analyzed by the discrete-sectional model. In the PCDP, most of the NO is converted into NO/sub 2/ and, later, into HNO/sub 3/ which reacts with NH/sub 3/ to form the NH/sub 4/NO/sub 3/ particle. In the beginning of the reactor, we have the high concentration of small size particles and, later, the particle size distribution in the reactor becomes bimodal with the large size and small size particles and, finally, becomes monodisperse with the large size particles. As the average electron concentration increases, it takes a shorter reactor length to remove the NO/sub x/. As the initial NO and H/sub 2/O concentrations decrease, the NH/sub 3/ is consumed more slowly to form the ammonium nitrates particles. As the averaged electron concentration and initial H/sub 2/O concentration increase, the large size particles grow more quickly and the particle size distribution becomes bimodal earlier. As the initial NO and NH/sub 3/ concentrations increase, the diameter of large size particles becomes larger by the faster coagulation between particles. The predicted NO/sub x/ conversion and particle size distribution were in close agreements with the published experimental results at the averaged electron concentration of 2/spl times/10/sup 5/ cm/sup -3/ in this study. 相似文献
13.
The radial expansion velocities and diameters of spark channels in air are measured by the plasma-metal contact method. An
LC discharge circuit with energy up to 50 kJ and with current frequencies ranging from ∼102 to ∼104 Hz served as the source of the channels. It is concluded on the basis of the results obtained that the previously proposed
automatic plasma crowbar based on the expansion of spark channels in gases is a universal switch for an inductive load in
LC discharge circuits that could find very wide applications in high pulsed current and magnetic field technology.
Zh. Tekh. Fiz. 68, 133–136 (February 1998) 相似文献
14.
G. G. Petrash 《Bulletin of the Lebedev Physics Institute》2007,34(7):208-213
The effect of the prepulse electron density and population of the lower laser (metastable) level on lasing characteristics of the pulsed copper vapor laser is considered. In the analysis of their effect, attention is paid to the need to consider the correlation of these parameters. It is emphasized that the effect of the prepulse electron density depends on the electron heating rate at the beginning of the excitation pulse. The conditions controlling the electron heating rate and methods for reducing the effect of this parameter are considered. 相似文献
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针对空调压缩机辐射声场的不同场点噪声声品质的差异,采用心理学声品质参量即响度、尖锐度、总感觉噪度,对压缩机辐射声场的不同场点噪声进行声品质客观参量分析,研究压缩机场点噪声声品质客观参量值变化规律。通过特征响度研究各场点噪声响度在频域的分布,并得出压缩机各场点噪声特征响度峰值所在噪声频带。实验结果表明,对于处在压缩机不同方向上的场点,其噪声声品质客观参量值存在明显差异,但其噪声特征响度峰值却处在相同的噪声频带。研究工作为压缩机全方向降噪提供参考依据也为研究压缩机的噪声声品质探索了一种新思路。 相似文献
17.
We establish a single diode laser sensor system to obtain temperature and water concentration in CH4/air premixed flame.Line-of-sight properties are analyzed,but line-of-sight results are not path average values for temperature measurements.The measurements are performed on a flat burner based on scannedwavelength direct absorption spectroscopy using two adjacent water lines at 7153.75 and 7154.35 cm 1.Real-time results are acquired using a data acquisition card with a Labview data processing program.The standard uncertainties of the temperature and water concentration measurements are 2.3% and 5.1%,respectively. 相似文献
18.
For indoor air purification, long-term operation of the air purifier induces the growth of germs and the proliferation of molds, and results in the performance degradation of the air filter. Non-thermal plasma technology could be an effective countermeasure against these problems. Ozone generated by the electric discharge has significant germicidal power and does not produce secondary residual contaminants. Electrostatic force can enable the air filter to function as an electric precipitator. In this study, a non-thermal plasma reactor with wire-wire type electrodes and an air filter is investigated experimentally to improve the performance of the used air filter. 相似文献
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20.
Semipolar(1122) and polar(0001) InGaN grown on sapphire substrate by using pulsed metal organic chemical vapor deposition
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High indium semipolar(1122) and polar(0001) In Ga N layers each with a thickness of about 100 nm are realized simultaneously on sapphire substrates by pulsed metal organic chemical vapor deposition(MOCVD). The morphology evolution, structural and optical characteristics are also studied. The indium content in the layer of the surface(1122)is larger than that of the surface(0001), which is confirmed by reciprocal space map, photoluminescence spectrum and secondary ion mass spectrometer. Additionally, the(0001) surface with island-like morphology shows inhomogeneous indium incorporation, while the(1122) surface with a spiral-like morphology shows a better homogeneous In composition.This feature is also demonstrated by the monochromatic cathodoluminescence map. 相似文献