气相中2Ca＋介入N2O与CO, N2O与H2反应的计算研究

本文采用密度泛函理论DFT-UB3LYP方法, 在6-311+G(2d, p)的基组下, 计算研究了气相中Ca+离子介入N2O (1∑+)和CO (1∑+) 与N2O (1∑+) 和 H2 (1∑+g)反应的微观机理. 报道了二重态势能面上各反应物、中间体和过渡态的构型特征及能量, 并用频率分析和内禀反应坐标（IRC）方法对过渡态进行了验证. 计算结果表明,金属离子参与N2O和CO与N2O和H2的反应都分两步进行, 其中Ca+离子对反应N2O (X1∑+) + CO (1∑+)生成N2 (X1∑+g) + CO2 (1∑+g)比较Fe+, Ir+, Pt+等的金属离子有良好的催化作用, 而对反应N2O (X1∑+) + H2 (1∑+g) → N2 (1∑+g) + H2O (1A1) 催化作用不是很好,N2、CaOH+和H是该反应的主要产物,与实验观测结果相符, 并通过对金属离子亲氧性（OA）的计算, 从热力学方面进一步说明主题反应的可行性.     

气相中2Ca＋介入N2O与CO, N2O与H2反应的计算研究

本文采用密度泛函理论DFT-UB3LYP方法, 在6-311+G(2d, p)的基组下, 计算研究了气相中Ca+离子介入N2O (1∑+)和CO (1∑+) 与N2O (1∑+) 和 H2 (1∑+g)反应的微观机理. 报道了二重态势能面上各反应物、中间体和过渡态的构型特征及能量, 并用频率分析和内禀反应坐标（IRC）方法对过渡态进行了验证. 计算结果表明,金属离子参与N2O和CO与N2O和H2的反应都分两步进行, 其中Ca+离子对反应N2O (X1∑+) + CO (1∑+)生成N2 (X1∑+g) + CO2 (1∑+g)比较Fe+, Ir+, Pt+等的金属离子有良好的催化作用, 而对反应N2O (X1∑+) + H2 (1∑+g) → N2 (1∑+g) + H2O (1A1) 催化作用不是很好,N2、CaOH+和H是该反应的主要产物,与实验观测结果相符, 并通过对金属离子亲氧性（OA）的计算, 从热力学方面进一步说明主题反应的可行性.     

The 2ν2 band of 14N 16O2

The 2ν₂ band of ¹⁴N ¹⁶O₂ has been observed for the first time in the infrared, leading to precise energies for the K_a = 0, 1, 2 rotational levels of the (0 2 0) vibrational state. These levels have been reproduced within the experimental uncertainty using a Hamiltonian which takes into account the Coriolis interactions between (0 2 0) and (0 0 1) and between (1 0 0) and (0 0 1). In this way a precise band center ν₀ = 1498.3474 ± 0.0016 cm⁻¹ has been determined as well as improved rotational and coupling constants.     

CH(X2∏)+N2O的反应机理研究

在G2(B3LYP/MP2/CC)理论水平上研究了CH(X^2Ⅱ)自由基与氧化二氮（NNO）分子的反应。计算了反应体系的最低二重态势能面上各驻点的构型参数、振动频率和能量，揭示了此反应存在的两种机理和六个通道。基中HC和NNO复合，生成中间体HC(N)NO，解离得到产物HCN+NO，这是最主要的通道之一；HC插入NO键，克服38.9kJ/mol的势垒，产生富能的中间体HC(O)NN，预测了五个反应通道，其中主要反应通道为：NN+HCO.     

N2O异构体结构与解析势能函数

在B3P86/cc-PVTZ水平上,对N2O异构体进行优化计算,得出N2O基态的单重态能量最低,其稳定构型为C∞v构型,平衡核间距R1=0.1121 nm,R2=0.1177 nm,α＝180°,能量为-185.1188a.u.同时计算出基态的简正振动频率ω1(Π)=601.5010 cm-1,ω2(Σg)=1295.8518 cm-1和ω3(Σu)=2287.0627 cm-1.在此基础上,使用多体项展式理论方法,导出N2O分子的全空间解析势能函数,该势能函数准确再现了N2O(C∞v)平衡结构.     

O2/N2与O2/CO2条件下燃煤颗粒物的生成特性研究

将煤粉在O2/N2与O2/CO2条件下进行沉降炉燃烧实验,研究了燃煤颗粒物的质量粒径分布、生成浓度以及元素组成特性.研究结果表明,燃煤颗粒物均呈三模态粒径分布,气氛的改变不影响各模态的分布趋势.相同O2含量条件下,与O2/N2气氛相比,O2/CO2气氛中PM10和PM1的生成浓度均降低,PM1易挥发元素Na、K、S的含量升高,而难熔元素Si、Al、Mg、Ca、Fe的含量降低.随着O2浓度的增加,O2/N2燃烧气氛下PM10和PM1的生成浓度逐渐增加,O2/CO2燃烧气氛下PM10的生成浓度增加,而PM1的生成浓度先减小后增加.     

Bestimmung der 15N-Häufigkeit von N2O und N2 mittels emissionsspektrometrischer continuous-flow-Messung

Abstract

Tests were made for a quantitative decomposition of N₂O to N₂ and for the setting of a statistical equilibrium in mixtures with gaseous nitrogen of nonrandom distribution by emission spectrometric continuous-flow-measurements. Under high-frequency-discharge conditions a residence time of 0.5 seconds is enough for a quantitative decomposition. In this time the statistical balance in the mixture of N₂O and N₂ is reached. The determination of the relative ¹⁵N abundance in pure N₂O or N₂ gases or in mixtures of N₂O and N₂ in a continuous-flow-emissionspectrometer can directly be achieved.     

N2O+离子A2∑+电子态的光谱研究

用一束波长为360.55 nm的激光,通过N2O分子的(3+1)共振增强多光子电离过程制备纯净的母体离子N2O+X2Ⅱ3/2,1/2(000).用另一束可调谐激光将N2O+离子激发至预解离态A2Σ+,利用飞行时间质谱检测解离碎片NO+离子强度随光解光波长的变化,在278-328 nm波长范围内获得了光解碎片的激发(PHOFEX)谱.观测到了N2O+离子A2Σ+←X2Ⅱ电子跃迁较丰富的振动谱带.通过对PHOFEX光谱的标识,获得了A2∑+态较准确和全面的分子光谱常数.     

Si2N2O基体铌酸锂调制器有限元法研究

提出一种新型基于Si2N2O基体的LiNbO3行波调制器,利用有限元方法对该调制器进行数值分析并获得调制器的优化结构尺寸.该新型调制器带宽达到120 GHz,半波电压为3.5 V,特性阻抗为50.2 Ω.结果表明该调制器具有大的调制带宽和良好的阻抗匹配,在未来光通信中具有很好的应用前景.     

H2O对N复合氧化膜Cr2O3作用机制的理论研究

本文基于第一性原理方法,研究水对N复合氧化膜Cr2O3的作用机制。结果表明N的复合影响H2O在表面的吸附位点及吸附高度,N的溶入与Cr形成稳定作用,减缓H2O对表面Cr-O间的破坏作用,改善氧化膜表层结构,提高表面电化学稳定性。因此,N的复合可增强氧化膜对H2O的作用,同时改善氧化膜的结构稳定性,从而提高不锈钢的抗氧化性。     

N2O／C2H2FAAS法测定铝的干扰研究

本文研究了４０种单个无机离子、混和无机离子及２４种有机物在Ｎ２Ｏ／Ｃ２Ｈ２火焰中对铝吸收信号的干扰情况。并从物理干扰、光谱干扰和化学干扰等角度对它们的干扰机理作了解释。     

Detailed modeling of planar transcritical H2–O2–N2 flames

We first investigate a detailed high pressure flame model. Our model is based on the thermodynamics of irreversible processes, statistical mechanics, statistical thermodynamics, and the kinetic theory of dense gases. We study thermodynamic properties, chemical production rates, transport fluxes, and establish that entropy production is non-negative. We next investigate the structure of planar transcritical H₂–O₂–N₂ flames and perform a sensitivity analysis with respect to the model. Non-idealities in the equation of state and in the transport fluxes have a dramatic influence on the cold zone of the flame. Non-idealities in the chemical production rates – consistent with thermodynamics and important to insure positivity of entropy production – may also strongly influence flame structures at very high pressures. At sufficiently low temperatures, fresh mixtures of H₂–O₂–N₂ flames are found to be thermodynamically unstable, in agreement with experimental results. We finally study the influence of various parameters associated with the initial reactants on the structure of transcritical planar H₂–O₂–N₂ flames as well as lean and rich extinction limits.     

N2O脉冲高压直流放电的光谱研究

建立了一套产生瞬变物种的脉冲高压放电及其光谱探测的分子束装置,该装置的放电部分可在最高10kV电压条件下长期稳定工作,在数据采集中利用软件实现了取样积分器的功能,并且可以进行多通道数据的同时采集。利用此装置在几Pa压力下对N2O脉冲高压直流放电过程进行了研究,对得到的N2O (A~2Σ —~X2Πi)发射谱进行了标识,由振动光谱的强度得到了N2O ~A态的相对振动布居,和以往的研究结果相比,得到的N2O ~A态更偏离Bolzmann分布,产生的~A态是初生态。     

The 2CH excitation band in C2H2–N2O and 2CH+torsion combination bands in C2H2–N2O and C2H2–CO2

A preliminary analysis of the 2CH excitation band in C₂H₂–N₂O in the 1.5 µm range (K. Didriche, C. Lauzin, P. Macko, M. Herman and W.J. Lafferty, Chem. Phys. Letters 469, 35 (2009).), only considering 117 low J-, and K_a - vibration-rotation lines, is significantly extended thanks to the analysis of new spectra including very regular series of lines with J/K_a up to 31/15. 1271 b-type lines were assigned. Perturbations are briefly discussed. The rotational temperature in the experiments is estimated to be 20?K and the upper state mean half-time is 1.6?ns for non perturbed levels. The previous analyses of the 2CH + torsion band in C₂H₂–N₂O and in C₂H₂–CO₂ (C. Lauzin, K. Didriche, T. Földes and M. Herman, Mol. Phys. 109, 2105 (2011).), are also extended to include 286 and 234 lines, respectively, also correcting for calibration errors. New rotational constants are obtained using a rigid rotor Hamiltonian by simultaneously fitting the ground, 2CH and 2CH + torsion states in C₂H₂–N₂O, and the latter state, only, in C₂H₂–CO₂.     

N2O+离子A2∑+电子态的光解动力学研究

用一束波长为360.55nm的激光,通过N2O分子的(3+1)共振多光子电离(REMPI)过程制备纯净且布居完全处于X2Ⅱ(000)态的母体离子N2O+,然后用另一束波长在275-328nm范围内的可调谐激光将制备的N2O+离子激发至预解离电子态A2∑+.实验发现,由于解离碎片NO+所具有的一定的反冲速度,其TOF质谱峰明显比N2O+母体宽.通过分析NO+碎片TOF质谱峰形状,得到了解离产物的总平均平动能;通过考察随光解能量的变化,发现光解能量在32000cm-1附近约250cm-1的变化范围内,值由约8000cm-1突然减小至约1600cm-1.通过分析,在光解能量小于32000cm-1的区域,解离通道为NO+(X1∑+)+N(4S);而在光解能量大于32000cm-1的区域,另一个具有较高解离限的解离通道,NO+(X1∑+)+N(2D),开启并完全取代N(4S)通道成为解离的惟一通道.根据实验结果,对在所研究的光解能量范围内的N2O+离子A2∑+电子态预解离机理进行了探讨.     

单斜辉石固溶体CaMgSi2O6—N4AlSi2O6的合成机理研究

研究了压力和温度对单斜辉石的结晶和晶粒纤维编织的影响。在较低的晶化温度下压力对单斜辉石结晶的影响很明显，这种影响随温度升高而减弱。然而，压力对单斜辉石晶粒纤维编织的影响正相反，在相同的高温下，较高压力下晶化的单斜辉石晶粒纤维比较低压力下得到的晶粒纤维粗壮，而且编织紧密。