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本工作采用光学发射谱方法测量了TEA CO2脉冲激光辐射SiH4+CH4系统产生的等离子体反应过程中的发射谱特性,探测到了Si,Si^+,Si^2+,C,C^+,C^2+,CH,SiH,SiH^+,Si2和H的特征辐射,研究了含C,Si碎片粒子光谱随实验条件的变化规律,并讨论了反应条件对OES的影响。 相似文献
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在较宽的温度(4.2-80K)和磁场(0-8T)范围内测量了YBa2Cu3O7-δ和Y0.9Eu0.1Ba2·Cu3O7-δ样品的磁滞回线和磁弛豫,研究了其M(t),Jc(T)和Ueff(J)关系,并与现有的一些理论模型所预言的结果进行了比较。结果表明:(1)与YBa2Cu3O7-δ相比,Y0.9Eu0.1·Ba2Cu3O7-δ样品的有效钉扎势和无磁通蠕动时的临界电流密度有明显提高,表明Eu的部分替代引入了新的、具有更大的钉扎势的钉扎中心;(2)与其它模型相比,集体钉扎——蠕动理论对我们的实验结果作了更好的描述,因而本文为这一理论提供了新的实验证据。
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报道在超声射流冷却条件下用同步辐射VUV光源研究CH2Br2的振动自电离结构.根据测量的105—123nm范围内母体离子(CH2Br2+)的光电离产率曲线,获得CH2Br2的绝热电离势为10.23±0.01eV.CH2Br2+的最低三个电子激发态,即A(2A2),B(2B1),C(2A1)分别位于10.78±0.01eV,11.20±0.01eV和11.27±0.01eV.在115.01—121.15nm范围内,观察到CH2Br2自电离峰叠加在若干台阶结构上,台阶平均宽度为716.8±40.0cm-1,对应于CH2Br2+(X2B2)中Br-C-Br反对称的伸缩振动(v9),所有的峰均归属为收敛于CH2Br2+(X2B2,v+)振动能级的ns,np和nd自电离Rydberg态.此外,对CH2Br2光解离电离产生离子型自由基CH2Br+(X)的光电离产率曲线的结构也进行了归属
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Yan M. Goedheer W.J. 《IEEE transactions on plasma science. IEEE Nuclear and Plasma Sciences Society》1999,27(5):1399-1405
In this paper we report on a study of SiH4/H2 radio-frequency discharges using the particle-in-cell/Monte Carlo (PIC/MC) method. A special procedure based on the rate balance for negative ions has been developed to speed up the simulation for this kind of electronegative discharge. The electron energy distribution function and the angular and energy distribution function of ions arriving at the substrate have been studied at different discharge settings (frequency, pressure, voltage, and power). The simulations show that the electrons are heated ohmically, so the average electron energy can be increased only by increasing the voltage. A high radical density, a high and more directional ion flux, and a low average ion energy can be obtained by a combination of a high frequency and a low RF voltage. The behavior of the dissociation rate with the discharge parameters is consistent with the experimentally observed consumption of SiH4. The simulated ion energy distribution functions are in good agreement with experimental results 相似文献
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Mixtures of AgI and PbI2 cooled from the melt result in the peritectic formation of a fast ion conducting phase centred about Ag4PbI6, which is face centred cubic with a = 6.33(5)A; this phase exhibits high electrical conductivity. On cooling to about 125°C, dissociation occurs to γAgI and PbI2, accompanied by the transient formation of another phase, centred about Ag2PbI4. A modified form of the T-x section of the equilibrium phase diagram at AgI concentrations greater than 60 mole % and below 300°C is proposed. 相似文献
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报道了H+5的实验结果.分析讨论了H+5的 形成和分解途径.根据理论分析,以稳定的H+3为核心与一个或多个氢分子结合可能形成稳定的H+ sup>n氢团簇离子.另一方面,在高频离子源中, 有发生H+3与H2反应的条件.实 验中,从高频离子源引出的离子束被静电加速器加速,然后用9
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+5团簇离子')" href="#">H+5团簇离子
3中性团簇')" href="#">H3中性团簇
4中性团簇')" href="#">H4中性团簇 相似文献
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Using two-frequency technique for the multiple photon dissociation of OsO4 molecule by IR laser radiation, the following new results have been obtained: 1. the narrow resonances of multiple photon absorption on few low lying vibrational transitions have been found in the dissociation yield as a function of exciting frequency ν1; 2. the structure of the dissociation yield as a function of dissociating frequency ν2 connected with high lying vibrational transition has been studied; 3. the kinetic of the vibration relaxation of high vibrationally excited molecules was investigated; 4. the unimolecular character of the multiple photon dissociation of OsO4 has been proved. 相似文献
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利用辉光放电技术采用等离子体质谱诊断的方法研究了不同工作 压强下H2/C4H8混合气体等离子体中 主要正离子成分及其能量的变化规律, 并分析了压强对H2/C4H8混合气体的离解机理以及主要正离子形成过程的影响. 结果表明: 随着工作压强的增加, 碳氢碎片离子的浓度和能量均逐渐减小. 当工作压强为5 Pa时, H2/C4H8混合气体等离子体中C3H5+相对浓度最大; 压强为10 Pa时, C3H3+相对浓度最大; 压强为15, 20 Pa时, C2H5+相对浓度最大; 压强为25 Pa时, C4H9+相对浓度最大. 对H2/C4H8等离子体中的主要组分及其能量分布所进行的定性分析, 将为H2/C4H8混合气体辉光放电聚合物涂层的工艺参数优化提供参考技术基础.
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辉光放电技术
等离子体质谱诊断
工作压强 相似文献
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Diffusion in the four high-temperature sulphate phases Li2SO4, LiNaSO4, LiAgSO4 and Li4Zn(SO4)3 was studied extensively some 20–30 years ago. We have now carried out a re-evaluation where we include information obtained from a number of studies of other properties. The data are adjusted slightly due to the use of another type of regression analysis. It is characteristic of the four phases that they are both plastic crystals and solid electrolytes (superionic conductors). The cause of the high conductivity is that the mobility of the cations is strongly enhanced by the rotational motion of the translationally static sulphate ions. This is observed not only for the abundant cations, but also for other cations present (mono- as well as polyvalent) and for monovalent anions. Furthermore, both bulk diffusion and transfer along high diffusivity paths are affected. In addition, one can distinguish between different contributions to the bulk diffusion. The ionic radius is a very important parameter, since it determines the solid solubility and the distribution of the ions between the sites that are available in the lattice. All this affects the relative importance of several competing diffusion mechanisms. This gives a qualitative explanation of an anomalous correlation which has been observed in FCC Li2SO4 for monovalent ions (cations as well as anions), namely that both the diffusion coefficients D, and the activation energies Q, decrease when the radius is increased. This holds for hard-core cations (Li, Na, K, Rb), polarizable cations (Ag, Tl) and anions (F, Cl, Br). On the other hand, the situation is normal for divalent cations for which an increase in D corresponds to a decrease in Q. This is the case for hard-core ions (Mg, Ca) as well as for polarizable ones (Zn, Cd, Pb). Migration of the large ions Cs+ and SO2−4 appears to be specially sensitive to how the experiment is prepared. Diffusion in BCC LiNaSO4 and LiAgSO4 has been studied for the two main cations as well as for some dopant ions. A general conclusion is that studies of diffusion of several ions in the same structure can give information that cannot be obtained by other types of experiments. 相似文献
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Measurements in SF6?H2 mixtures of HF1 fluorescence at 2.8 μm induced by pulsed CO2 laser radiation are reported. The dependence of fluorescence intensity on laser fluence is found to be strongly affected by the laser beam geometry in the interaction region. Our results show that the technique of HF1 fluorescence intensity detection can be a sensitive and reliable single-shot measure of multiple-photon dissociation of SF6 in a collisionless regime on condition that the laser fluence is uniform along the interaction region which is monitored. 相似文献
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The nonohmic electrical features of (Ca1/4,Cu3/4)TiO3 perovskite ceramics, which have very strong gigantic dielectric is believed originate from potential barriers at the grain boundaries. In the present study, we used the admittance and impedance spectroscopy technique to investigate (Ca1/4,Cu3/4)TiO3 perovskite ceramics with low nonohmic electrical properties. The study was conducted under two different conditions: on as-sintered ceramics and on ceramics thermally treated in an oxygen-rich atmosphere. The results confirm that thermal treatment in oxygen-rich atmospheres influence the nonohmic properties. Annealing at oxygen-rich atmospheres improve the nonohmic behavior and annealing at oxygen-poor atmospheres decrease the nonohmic properties, a behavior already reported for common metal oxide nonohmic devices and here firstly evidenced for the (Ca1/4,Cu3/4)TiO3 perovskite related materials. The results show that oxygen also influences the capacitance values at low frequencies, a behavior that is indicative of the Schottky-type nature of the potential barrier. 相似文献
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We have studied the adsorption and desorption of thiophene on polycrystalline UO2 as function of coverage, over the temperature range 100-640 K, using X-ray photoelectron spectroscopy (XPS), temperature programmed desorption (TPD) and electron stimulated desorption (ESD). Thiophene is found to adsorb molecularly on stoichiometric UO2. C 1s and S 2p XPS spectra are measured at different thiophene exposures and at different temperatures; they show no evidence for the presence of dissociation fragments, confirming that thiophene adsorbs and desorbs molecularly on a polycrystalline stoichiometric UO2 surface. The variation of the S 2p and C 1s intensity as function of exposure, together with ESD measurements of O+ as function of exposure, can be connected to the growth mode of a thiophene film on UO2; the thiophene film converts from a flat-lying configuration to an inclined structure as coverage increases. The effects of X-rays, UV, and electron irradiation on thiophene films have been studied in two different coverage regimes, monolayer and multilayer. Irradiation leads to a modification of thiophene films, and appreciable concentrations of species stable to 640 K are present on the surface for both regimes. The XPS results suggest that irradiation induces polymerization and oligomerization, as well as formation of thiolates and dissociation fragments of thiophene. The adsorption and reactivity of thiophene on defective UO2 surfaces have also been studied. The O vacancies and defects in the oxide surface cause cleavage of C-H and C-S bonds leading to the dissociation of thiophene at temperatures as low as 100 K. These results illustrate the important role played by O vacancies in the chemistry of thiophene over an oxide surface. 相似文献