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1.
建立了低温等离子体技术处理N2/NO气氛中NO的实验系统,利用介质阻挡放电发射光谱诊断法分析了NTP技术处理NO的反应机理,以及研究了NTP系统的运行参数和N2体积流量对NO转化率的影响规律。研究结果表明,随着V(P-P)的增加,N2发射光谱强度相对于NO发射光谱强度的比值增加,N2第二正带系发射光谱强度增加,表明放电区间的高能电子浓度增大,有利于N2离解成N原子,从而促使NO还原转化;增加N2体积流量会使NO转化率降低,NO2浓度升高。 相似文献
2.
N2O Plasma表面处理对SiNx基IGZO-TFT性能的影响 总被引:1,自引:1,他引:0
采用N2O plasma处理SiNx薄膜作为绝缘层,以室温下沉积的铟镓锌氧化物(IGZO)作为有源层制备了 IGZO薄膜晶体管。与常规的IGZO-TFT相比,N2O plasma处理过的IGZO-TFT的迁移率由原来的4.5 cm2·V-1·s-1增 加至8.1 cm2·V-1·s-1,阈值电压由原来的11.5 V减小至3.2 V,亚阈值摆由原来的1.25 V/decade减小至0.9 V/decade。采用C-V方法计算了两种器件的陷阱态,结果发现N2O plasma处理过的IGZO-TFT的陷阱态明显小于普通的IGZO-TFT的陷阱态,表明N2O plasma处理SiNx绝缘层是一种改善IGZO-TFT器件性能的有效方法。 相似文献
3.
采用两维PIC/MCC模型模拟了氮气微空心阴极放电以及轰击离子 (N2+,N+) 的钛阴极溅射. 主要计算了氮气微空心阴极放电离子 (N2+,N+) 及溅射原子Ti的行为分布, 并研究了溅射Ti 原子的热化过程. 结果表明: 在模拟条件下, 空心阴极效应是负辉区叠加的电子震荡; 在对应条件下, 微空心较传统空心放电两种离子 (N2+,N+) 密度均大两个量级, 两种离子的平均能量的分布及大小几乎相同; 在放电空间N+的密度约为N2+的1/6, 最大能量约大2倍; 在不同参数 (P, T, V)下, 轰击阴极内表面的氮离子(N2+,N+)的密度近似均匀, 其平均能量几乎相等; 从阴极溅射出的Ti原子的初始平均能量约6.8 eV, 离开阴极约0.15 mm处几乎完全被热化. 模拟结果为N2微空心阴极放电等离子体特性的认识提供了参考依据.
关键词:
微空心阴极放电
PIC/MC模拟
2等离子体')" href="#">N2等离子体 相似文献
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利用感应耦合等离子体增强化学气相沉积法以Ar,He,N2和B2H6为反应气体制备了高纯立方氮化硼薄膜.用四极质谱仪对等离子体状况进行了系统的分析,发现B2H6完全被电离而N2只是部分被电离.H2和过量的N2在等离子体中生成大量中性的H原子和活化的N*2,它们与表面的相互作用严重地阻碍了立方
关键词:
立方氮化硼薄膜
等离子体
质谱 相似文献
6.
甲醇是一种很有前途的清洁能源,有望替代不可再生的石油能源.因此,将储量巨大,但不易运输的甲烷氧化为甲醇具有十分重要的意义.首先通过密度泛函理论(density functional theory, DFT)计算研究了Sc原子与C24N24之间的稳定性.结果表明,Sc原子与C24N24的结合能(-9.064 eV)小于Sc原子的内聚能(-4.518 eV),即Sc@C24N24具有良好的稳定性.在此基础上,进一步研究了甲烷在Sc@C24N24表面催化氧化制备甲醇的工艺过程,以N2O为氧化剂在Sc@C24N24单原子上进行甲醇的催化氧化反应.结果表明:N2O首先吸附在Sc@C24N24上,然后直接分解为N2和Oads.N2... 相似文献
7.
基于量子化学密度泛函理论研究了NO与CO、NCO在均相条件下的反应机理并进行了动力学和平衡常数的分析. CO与NO的均相反应存在两条反应路径:两者首先反应形成中间体CNO2,CNO2不易稳定存在,其继续与CO、NO反应分别生成NCO、N2O. NCO的生成速率大于N2O,但两条反应路径的反应速率常数都很小.与已发现的反应路径相比,反应中间体CNO2可以降低均相条件下CO与NO的反应能垒,分析发现CNO2中的N原子是易发生反应的活性位点. NCO与NO的反应同样存在两条路径,优势反应路径随温度升高而改变,但非优势路径对反应的贡献不能忽略,分析平衡常数可知N2的存在对反应影响可以忽略,因此燃烧环境中NCO与NO的反应既生成N2O和CO,也生成N2和CO2. 相似文献
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10.
快脉冲直线变压器型驱动源(FLTD)是近年来快速发展的新型脉冲功率源技术,多采用多间隙气体开关作为开关器件。电晕均压措施有利于提升开关击穿性能,但不同气体中电晕放电有显著区别。本文首先研究了空气中针电极对单间隙电晕放电特性的影响,确定了电晕针电极的尺寸,之后研究了N2,CO2,SF6/N2混合气体、C4F7N/N2混合气体中的电晕放电特性,研究了电晕均压6间隙气体开关击穿电压及其稳定性随气体种类和气压的变化规律。实验结果表明,N2中电晕电流较大且不稳定,空气中电晕电流比N2中低,且电晕放电较为稳定,微量强电负性气体加入会极大降低电晕放电电流。当采用空气和N2作绝缘介质时,气体开关击穿电压随气压升高线性增加,但存在低值击穿,微量强电负性气体混合N2可显著提升击穿电压的稳定性。1%SF6/99%N2混合气体在0.18 MPa时,击穿电压约为197.33 kV,标准偏差占击穿电压比例为1.50%,1% C4F7N /99%N2混合气体在0.15 MPa时,击穿电压约为190.42 kV,标准偏差为0.55%。这表明,微量环保替代气体C4F7N与N2的混合气体对于提升多间隙气体开关击穿电压稳定性有显著作用。 相似文献
11.
Field-induced ionization and Coulomb explosion of nitrogen 总被引:1,自引:0,他引:1
C.Y. Wu H.Z. Ren T.T. Liu R. Ma H. Yang H.B. Jiang Q.H. Gong 《Applied physics. B, Lasers and optics》2002,75(1):91-96
Femtosecond-laser field-induced ionization and Coulomb explosion of diatomic nitrogen were systematically investigated using
time-of-flight mass and photoelectron spectrometry. Both linearly and circularly polarized femtosecond laser pulses were used
at intensities varying from 5×1013 to 2×1015 W/cm2. Strong N2
+, N2
2+, N+, N2+ and N3+ ion signals were observed for horizontally polarized pulses. Moreover, signals from the atomic ions exhibited a double-peak
structure. Suppression of ionization was observed for circularly polarized pulses, while for vertically polarized pulses,
only N2
+ and N2
2+ ions were observed. The angular distributions of the ions were measured under zero-field conditions in the ionization zone.
The atomic ions N+, N2+ and N3+ exhibited highly anisotropic distributions, with maxima along the laser polarization vector and zeroes normal to the laser
polarization vector. In contrast to the atomic ions, N2
+ exhibited a strong isotropic angular distribution. These observations indicate that dynamic alignment is responsible for
the observed anisotropic angular distribution of the atomic ions. The kinetic energy spectrum of the photoelectrons is featureless
and broad, extending above the ponderomotive potential of the laser pulse. The angular distribution is markedly anisotropic,
with a maximum along the laser polarization vector. These observations further support the notion that the field-ionization
mechanism is dominant under our experimental conditions.
Received: 29 January 2002 / Revised version: 15 March 2002 / Published online: 12 July 2002 相似文献
12.
Fifty new laser lines have been observed in continuous emission from an N2O laser by placing a hot N2O absorber cell inside the laser cavity to suppress the regular laser lines. The new lines are identified as rotation-vibration transitions of the (0002–1001) band of N2O. 相似文献
13.
G. Gagliardi F. Tamassia P. De Natale C. Gmachl F. Capasso D.L. Sivco J.N. Baillargeon A.L. Hutchinson A.Y. Cho 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2002,19(3):327-331
A continuous wave quantum cascade laser (QCL), operating near 8.1 μm, was used for wavelength modulation spectroscopy of methane
(CH4) and nitrous oxide (N2O) stable isotopes. Several rotational transitions of 14N2
16O, 15N14N16O, 14N2
18O, 14N2
17O, 13CH4 and 12CH4 fundamental bands were detected. The noise-equivalent absorbance was measured to be less than 10-5 in a 1-Hz bandwidth. A characterization of the laser source was also performed. The use of a QCL spectrometer for high-precision
isotope ratio measurements is discussed.
Received 14 March 2002 相似文献
14.
Hiroshi Akagi Tatsuya Kasajima Takayuki Kumada Ryuji Itakura Atsushi Yokoyama Hirokazu Hasegawa Yasuhiro Ohshima 《Applied physics. B, Lasers and optics》2012,109(1):75-80
We demonstrate laser nitrogen isotope separation, which is based on field-free alignment and angular-dependent ionization of 14N2 and 15N2 isotopologues. A linearly polarized short laser pulse (???~?795?nm, ?????~?60?fs) creates rotational wave packets in the isotopologues, which periodically revive with different revival times as a result of different moments of inertia. Another linearly polarized short laser pulse (???~?795?nm, ?????~?60?fs) ionizes one of the isotopologues selectively as a result of their different angular distributions. In the present experiments, the ion yield ratio R [=I(15N2 +)/I(14N2 +)] can be changed in the range from 0.85 to 1.22, depending on the time delay between the two laser pulses. 相似文献
15.
M. Jackson B. Chuzles C. Dirocco P. Noffke L. R. Zink 《Applied physics. B, Lasers and optics》2005,80(8):945-947
A three-laser heterodyne system has been used to measure the frequencies of four previously observed far-infrared laser emissions generated by optically pumping either hydrazine (N2H4) or its fully deuterated isotope (N2D4) with a continuous-wave carbon dioxide laser. These newly measured frequencies have fractional uncertainties of ± 2 × 10−7 and correspond to laser wavelengths ranging from 63.9 to 158.4 μm. This work represents the first measurement of a N2D4 laser frequency. 相似文献
16.
P. Shoja-Chaghervand E. Bjarnov R.H. Schwendeman 《Journal of Molecular Spectroscopy》1983,97(2):287-305
Transitions in the ν2 band of 14NH3 were recorded by means of an infrared laser microwave two-photon spectrometer. The spectrometer, which uses a minicomputer to step the microwave frequency and record the spectrum, is described. With sample cells outside the laser cavity good lineshapes are obtained, so that the accuracy of frequency measurement was limited by the resettability of the CO2 or N2O lasers employed, ~0.0002 cm?1. The present data are compared to previously obtained results based on CO2 or N2O laser frequencies and to recently reported calculations. Rotational constants derived for the hypothetical inversion-free ground and v2 = 1 states are reported. 相似文献
17.
Joachim Mohn Christine Steinlin Lutz Merbold Lukas Emmenegger Frank Hagedorn 《Isotopes in environmental and health studies》2013,49(4):520-531
Nitrous oxide (N2O) emissions from snow-covered soils represent a significant fraction of the annual flux from alpine, subalpine or cold-temperate regions. In winter 2010–2011, we investigated the temporal variability of N2O emissions and source processes from a subalpine valley in the Swiss Alps. The study included regular measurements of N2O snow profiles at a fixed location and an intensive sampling campaign along a transversal cut through the valley with grassland at the bottom and coniferous forest at the slopes. During the intensive campaign, recently developed laser spectroscopy was employed for high-precision N2O isotopomer analysis. Maximum N2O fluxes (0.77±0.64 nmol m?2 h?1) were found for periods with elevated air temperature and, in contrast to our expectations, were higher from forest than from grassland in mid-February. At maximum snow height (63 cm) the main N2O source processes were heterotrophic denitrification and nitrifier denitrification. The reduction of N2O by heterotrophic denitrifiers was much more pronounced for the grassland compared with the forest soil, as indicated by the 15N site preferences of 16.4±11.5 ‰ (grassland) and?1.6±2.1 ‰ (forest). This illustrates the potential of laser spectroscopic N2O isotopomer analysis for the identification of source processes even at low emission rates in nutrient poor ecosystems. 相似文献
18.
Frequency measurements are given for the 0001-0000 and 0111-0110 bands of N2O from 1257 to 1340 cm?1. The measurements utilize heterodyne techniques by measuring small frequency differences between a tunable diode laser locked to the center of an N2O absorption line and harmonic combinations of frequencies of radiation from two CO2 Lamb-dip-stabilized lasers. The measurements are facilitated by the use of the CO laser as a transfer laser whose frequency is also measured. These measurements have been combined with other data to provide new band constants and frequency calibration tables for several band systems of N2O in the following regions; 1215 to 1340, 1816 to 1930, and 2135 to 2268 cm?1. A correction factor is also provided for existing calibration tables near 590 cm?1. 相似文献
19.
A. N. Panchenko A. I. Suslov V. F. Tarasenko I. N. Konovalov A. E. Tel’minov 《Physics of Wave Phenomena》2009,17(4):251-276
The advantages of inductive energy storage (IES) generators for increasing the pulse energy, power, and duration for nitrogen
laser pumped by self-sustained transverse discharge have been experimentally demonstrated. A theoretical model is developed
and the operation of IES-pumped laser on nitrogen-electronegative gas mixtures is numerically simulated. It is shown experimentally
and theoretically that, adding electronegative gases, one can control the pulse shape of lasing on the C3II
u
-B3II
g
transition in nitrogen. The increase in the electric field strength in the laser gap in N2-NF3 and N2-SF6 mixtures produced 337.1-nm laser pulses consisting of two spaced peaks and 40–50-ns pulses close to rectangular. The increase
in the laser active volume to 6 l (discharge cross section to 6×10 cm2) in N2–SF6 mixtures made it possible to obtain the maximum output energy (Q=110 mJ) and UV power (P
las =6 MW). In N2-NF3 mixtures, the laser pulse duration was up to ∼100 ns with an energy up to Q=30 mJ. 相似文献
20.
A miniature tunable TEA CO2 laser using isotope 13C16O2 as the active medium is developed to extend the spectral range of CO2 lasers for further application. The optimization of the energy parameters of the tunable TEA 13C16O2 laser and the same laser using 12C16O2 are studied. When a gas mixture (13C16O2: N2: He = 1: 1: 3) at a total pressure of 6.4 × 104 Pa is used, the TEA 13C16O2 laser of a 45-cm3 active volume obtains 51 emission lines in the [0001–1000] and [0001–0200] bands. The maximum pulse energy of the TEA 13C16O2 laser is about 357 mJ. The same laser using the conventional gas mixture (12C16O2: N2: He = 1: 1: 3) at a pressure of 6.66 × 104 Pa is measured to obtain 69 laser emission lines and the maximum pulse energy of laser radiation is about 409 mJ. 相似文献