水汽分子碰撞加宽的理论研究

本文利用考虑短程强相互作用势、电四极矩_(H_2O)—电四极矩_(N_2)和电偶极矩_(H_2O)—电四极矩_(N_2)—相互作用的QFT理论(以下简称为QFT~*理论),计算了水汽分子纯转动带和_(v_2)振动带谱线的碰撞加宽线宽,以及v_(_2)振动带谱线线宽的温度依赖关系。结果表明:①利用QFT~*方法的计算值比Gamache等人的理论计算值更接近于实验值。③在计算水汽分子吸收谱线的氮分子碰撞加宽时,短程强相互作用势的影响是十分重要的,而电四极矩_(H_2O)—电四极矩_(N_2)相互作用的影响在任何情况下都是不大的,其贡献仅为1%左右。②压力加宽线宽的温度依赖关系是十分复杂的,字不仅与J有关,而且还与K_α有关。     

13CH4分子v3振动带空气和氮气加宽系数温度依赖性研究

采用中红外波段连续可调谐二极管激光器和自行研制的低温吸收池, 测量了温度为296 K, 252 K, 213 K, 173 K时, 3.38 μm附近¹³CH₄分子的四条跃迁谱线的氮气和空气加宽光谱; 首次通过实验获得空气和氮气对¹³CH₄分子的碰撞加宽系数, 以及谱线加宽系数的温度依赖系数. 实验过程中, 利用Voigt线型对所测量的光谱进行拟合. 实验结果表明, 氮气和空气对¹³CH₄分子的碰撞诱导加宽系数随温度的降低而增大; 相同温度下, 氮气对¹³CH₄分子的碰撞加宽系数普遍大于空气加宽系数. 实验数据为地球和外星体大气遥感探测提供了依据.     

水汽分子对CO_2谱线加宽的影响

报道了以高分辨力连续可调谐中红外差频激光为探测光源,结合可调长光程怀特池,利用直接吸收的方法探测了CO2的10011←10002带R支以及部分P支在室温下的水汽加宽吸收光谱。在2422cm-1到2457cm-1范围内共有26条吸收谱线被探测到,采用Voigt线型对吸收谱线进行拟合,得到了CO2光谱的水汽加宽系数,结果显示CO2的水汽加宽系数平均比干燥空气的加宽系数大52%。利用实验测得的CO2的水汽加宽系数与HITRAN04数据库中CO2谱线的线位置、线强和干燥的空气加宽系数进行比较,分析了在实际大气中(海平面,10km光程)不存在水汽和存在水汽(含有2.0kPa水汽)时该波段CO2的大气透过率,结果表明潮湿空气与干燥空气之间的最大透过率差约为0.5‰。     

水汽分子对CO2谱线加宽的影响

报道了以高分辨力连续可调谐中红外差频激光为探测光源,结合可调长光程怀特池,利用直接吸收的方法探测了CO2的10011←10002带R支以及部分P支在室温下的水汽加宽吸收光谱。在2 422 cm-1到2 457 cm-1范围内共有26条吸收谱线被探测到,采用Voigt线型对吸收谱线进行拟合,得到了CO2光谱的水汽加宽系数,结果显示CO2的水汽加宽系数平均比干燥空气的加宽系数大52%。利用实验测得的CO2的水汽加宽系数与HITRAN04数据库中CO2谱线的线位置、线强和干燥的空气加宽系数进行比较,分析了在实际大气中(海平面,10 km光程)不存在水汽和存在水汽(含有2.0 kPa水汽)时该波段CO2的大气透过率,结果表明潮湿空气与干燥空气之间的最大透过率差约为0.5‰。     

CO电子基态P线系跃迁谱线的理论研究

基于微分的思想,结合经典的双原子分子跃迁谱线表达式,提出了预言双原子分子P线系高激发振-转跃迁谱线的新解析物理公式.对于某分子电子体系的某一P支跃迁带,利用实验上获得的一组(15条)精确的跃迁谱线和该跃迁带对应的上下振动态的转动常数(B_υ',B_υ″)的精确数据,该公式不仅可以精确地重复已知的实验跃迁谱线,而且还能预测出实验上难以获得的更高激发态的跃迁谱线数据.利用该公式,研究了CO分子电子基态的(2,0)振-转跃迁带的< 关键词： 双原子分子 发射光谱 P线系')" href="#">P线系 CO     

压强对空气/氩气介质阻挡放电中等离子体温度的影响

使用水电极介质阻挡放电装置,在氩气和空气的混合气体放电中,利用发射光谱法,研究了电子激发温度和分子振动温度随气体压强的变化关系。通过氩原子763.51 nm(2P₆→1S₅)和772.42 nm(2P₆→1S₃)两条谱线强度比法计算电子激发温度;通过氮分子第二正带系(C3Π_u→B3Π_g)的发射谱线计算氮分子的振动温度;对氮分子离子391.4 nm和激发态的氮分子337.1 nm两条发射谱线的相对强度进行了测量,以进一步研究电子能量的变化。实验表明,随着压强从20 kPa增大到60 kPa, 电子激发温度减小,分子振动温度减小, 氮分子离子谱线与激发态的氮分子谱线强度之比减小。     

基于光谱拟合的燃烧场气体参数测量方法研究

基于波长调制光谱(WMS)理论,提出一种利用光谱拟合实现燃烧场气体参数测量的方法;通过拟合谱线的谐波信号实现谱线积分吸光度、多普勒线宽和碰撞线宽的测量,进而实现燃烧场内气体温度、压强和水蒸气浓度的测量;通过数值仿真研究了积分吸光度和碰撞线宽对谐波信号的影响,并在样品池中进行实验研究。结果表明:谐波信号光谱对积分吸光度的灵敏度约为1,而对碰撞线宽的灵敏度则随碰撞线宽增大而先增大后基本不变;光谱拟合测量方法具有较高的测量精度,气体温度、压强、水蒸气物质的量分数的测量值与预测值的最大相对偏差分别小于4%、6%、5.5%。     

空气介质阻挡放电不同放电模式的光谱特性

采用光谱方法,研究了空气介质阻挡放电中流光向类辉光转变时电子能量的变化。利用氮分子第二正带系(C3Π_u→B3Π_g)的发射谱线,测量了氮分子(C3Π_u)的振动温度。通过考察氮分子离子391.4 nm谱线强度与氮分子337.1 nm谱线强度之比,研究了电子平均能量的变化。结果表明,流光向类辉光转变时,氮分子(C3Π_u)的振动温度激增,氮分子离子391.4 nm相对谱线强度突增,表明类辉光放电模式中电子能量比流光放电模式中电子能量高很多。实验还发现,气隙间距不同,这两种放电模式转变所对应的转变气压不同,但转变气压与气隙间距的乘积值保持不变。     

氩气含量对空气介质阻挡放电发射光谱的影响

利用介质阻挡放电实验系统测量了空气介质阻挡放电的发射光谱,研究了氩气含量对空气介质阻挡放电发射光谱的影响。在280~500 nm波长范围内,发现了氮分子第二正带系Ｎ₂(Ｃ 3Π_ｕ-Ｂ 3Π_ｇ)的谱线和氮分子离子的第一负带系N+₂(B 3Σ＋_ｕ-Ｘ 2Σ＋_ｇ)的谱线。在相同条件下加入10%氩气后,起始放电电压由26 kV降低到23 kV,介质阻挡放电和发射光谱强度都增强,谱线的半宽明显加大。随氩气含量的增加,各个氮分子第二正带系谱线强度的变化趋势不同,而两条氮分子离子第一负带系谱线391.44和427.81 nm的光谱强度都是降低的。     

XeCl B-X跃迁自发辐射谱压力关系的理论计算(英文)

采用假定所有旋转能级独立辐射和碰撞加宽劳仑茨线宽的准平衡模型,对XeCl B-X跃迁自发辐射谱进行了数值模拟计算,从而解释了高气压下谱线的加宽现象.本文采用的方法还可适用于其它双原子准分子.     

ABSORPTION INTENSITIES, PRESSURE-BROADENING AND LINE MIXING PARAMETERS OF SOME LINES OF NH3 IN THE ν4 BAND

The intensities and foreign gas broadening coefficients of 57 selected lines of the ν₄ band of NH₃ have been measured in the region of 1550 cm^-1 using a high resolution Brucker Fourier transform spectrometer. The line intensities were obtained by using the methods of absorbance at the line center and by fitting Voigt profiles to the measured shapes of the lines. The latter method also provides the collisional widths of the lines. In addition, collision cross relaxation coefficients of O₂ and air foreign gases were measured for 9 doublets of NH₃ in the ν₄ band. The J and K quantum numbers dependencies of pressure-broadening coefficients and line intensities are discussed. The observed air broadening and cross relaxation coefficients were found to be in reasonable quantitative agreement with the concentration-weighted average of the N₂ and O₂ broadening coefficients. The comparison of our present and previous results obtained for the NH₃–H₂, NH₃–air, NH₃–N₂ and NH₃–CO₂ collisions shows an increase of the pressure broadening and cross relaxation coefficients with quadrupole moment of the foreign gas. The analysis of the line intensities was based on the third-order theory of line strengths and yields effective transition moments, vibrational band strengths and correction parameters of the symmetric and antisymmetric partial bands of the fundamental ν₄ band.     

Self-, Nitrogen-, and Oxygen-Broadening Coefficient Measurements in the ν1 Band of H2O Using a Difference Frequency Generation Spectrometer at 3 μm

In this paper we investigate the mid-infrared spectrum of the H₂¹⁶O molecule between 3367 and 3447 cm⁻¹ to study the gas-collision-broadened linewidths. The coherent radiation used in this experiment is produced through difference frequency generation in a periodically poled lithium niobate crystal. The spectroscopic analysis has concerned nine H₂O lines in the ν₁ fundamental vibrational band. For these lines the self-, N₂-, and O₂-broadening coefficients are measured at room temperature. From these data, the widths due to air broadening are also determined. The experimental collisional broadening coefficients are compared with other experimental data and with theoretical calculations based on the Anderson-Tsao-Cornutte and Robert-Bonamy theories. Lineshape analysis is performed using both the standard Voigt profile and the Nelkin-Ghatak profile for the hard collision regime. For all the investigated lines the agreement between the Voigt profile and the measured profiles is found to be good.     

碰撞诱导离解(CID)(Ⅱ)——I2(B3∏o+u)在高振动态(v′=62)的碰撞猝灭机理实验研究

本文研究了B³∏_o+u激发态I₂分子在高振动态v′=62时的碰撞猝灭过程。实验中得到了该能级I₂分子和其自身以及与其他气体分子(He,Ar,Kr,H₂,CO,N₂,O₂,CH₄,NH₃,C₂H₆,CCl₄)的碰撞猝灭速率常数,并且发现,在I关键词：     

Diode-laser measurements of O2, N2 and air-pressure broadening and shifting of NH3 in the 10 μm spectral region

Using a tunable diode-laser spectrometer, we have measured the O₂, N₂, air-shift and broadening coefficients for 5 lines of ammonia in the R branch of the ν₂ band. These lines are located in the spectral range 1030-1070 cm⁻¹. The pressure shift and broadening are obtained by fitting the measured shapes of these lines by a Voigt profile. The broadening parameters and shift coefficients are compared to the results of theoretical calculations based on the semiclassical Robert-Bonamy formalism (RB) in which the intermolecular potential includes electrostatic, induction, and dispersion energy contributions. The variation of these coefficients with rotational and vibrational quantum numbers is examined. The results are generally in satisfactory agreement with experimental data.     

The interacting states (020), (100), and (001) of H216O

A fit of 450 rotational levels of the 3 vibrational states (020), (100), and (001) of H₂¹⁶O has been performed using 57 effective constants. The Fermi-type interaction between (020) and (100) and the Coriolis type interaction between (100) and (001) as well as between (020) and (001) are taken into account. The part of the Hamiltonian which is diagonal in the vibrational quantum numbers is a Watson-type Hamiltonian. Most of the perturbed levels are well reproduced and the general agreement between experimental and calculated levels is satisfactory with 70% of the calculated ones falling within 15 × 10^?3 cm^?1 of the observed ones.     

Tunable infrared diode laser measurements of line strengths and collision widths of 12C16O at room temperature

A tunable diode laser was used to scan 33 vibration-rotation lines in the fundamental band of CO in room-temperature CO-N₂ and CO-Ar mixtures. Each absorption record was fitted with a Voigt profile from which the line strength and collision width were determined. The fundamental band strength of ¹²C¹⁶O at 273.2°K was determined to be 283±4 cm^-2 atm^-1. Results are also presented for the rotational quantum number dependence of the collision width for broadening by N₂ and Ar.     

The vibrational energy pattern in ethylene (12C2H4)

All known vibrational energies in ¹²C₂H₄([Xtilde]¹ A_g ) are collected. A block-diagonalized vibrational matrix Hamiltonian is set up, combining a Dunham expansion with the 2/10,10, 11/2,12, and the 5,5/9,9, 1,1/11,11,1,9/5,11 and 1,11/5,9 anharmonic resonances, with the normal modes numbered according to the most usual conventions in the previous literature. A step by step fitting procedure is applied. Vibrational constants are obtained, and vibrational assignments are provided and discussed. A slightly modified ensemble of vibrational constants is also produced by taking care of a more extended set of resonances between the CH-type vibrations. A new constant of the motion N = 3ν₁ + 3ν₅ + 3ν₉ + 3ν₁₁ + 2ν₂ + ν₁₀ + ν₁₂ is demonstrated to support the latter vibrational energy pattern.     

The interacting states (030), (110), and (011) of H216O

A fit of 382 rotational levels of the three vibrational states (030), (110), and (011) of H₂¹⁶O has been performed using 51 effective constants. The Fermi-type interaction between (030) and (110) and the Coriolis-type interaction between (110) and (011) as well as between (030) and (011) are taken into account. The part of the Hamiltonian which is diagonal in the vibrational quantum numbers is a Watson-type Hamiltonian. Considering the wide spread of J and K_a values, the general agreement between experimental and calculated levels is satisfactory. A comparison with the results relative to the states (020), (100), and (001) is given.     

Air-broadening parameters in the ν3 band of NO2 using a multispectrum fitting technique

Air-broadened linewidths, pressure-induced shift coefficients and their temperature dependences were retrieved for over 1000 transitions in the ν₃ band of ¹⁴N¹⁶O₂ at 6 μm. In addition, precise line center positions and relative intensities were also determined. The results were obtained by fitting simultaneously 27 spectra recorded at high resolution (0.002-0.006 cm⁻¹) with two Fourier transform spectrometers and gas sample temperatures ranging from 206 to 298 K. It was necessary to modify the multispectrum fitting software to accommodate constraints on the retrieved parameters of closely spaced spin-split doublets in order to successfully determine their broadening and shift parameters. The variations of the widths, shifts and their temperature dependences with the quantum numbers were investigated. Subsets of the observed linewidths were reproduced to within 3% using an empirical smoothing function.