Simultaneous determination of the ground level abundances of N2O,CO2, CO and H2O

The AFCRL atmospheric line-parameter listing has been used with a non-linear, least-squares method of analysis to obtain the abundances of N₂O and CO in a sample of ground level air with a precision of about 1%. Absorption coefficients calculated for N₂O agree satisfactory with laboratory measurements but an error of 0.0267 cm^-1 in the listed position of an H₂O line at 2205.250 cm^-1 has been corrected and errors in the positions and intensities of CO₂ lines between 2230 and 2250 cm^-1 have been observed.     

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.     

Vibrationally inelastic scattering of H∼ ions from H2, N2, O2 and CO2

State-resolved measurements are presented for vibrational excitation of H₂, N₂, O₂ and CO₂ by H^? impact in the collision energy rangeE _cm=20–180 eV and for scattering in the forward direction (0±0.5°). The data obtained from the measurements are the relative intensities and differential cross sections for vibrational excitation up toν′=4, the transition probabilitiesP _0→ν′ and the vibrational energy transferΔE _vib. For the systems H^?-H₂, N₂, O₂ the vibrational inelasticity increases in the order H₂-N₂-O₂. The mechanism for vibrational excitation in these systems is due to transient charge transfer from the H^? ion into antibonding orbitals of the target molecule which provides a bond stretching force during the collision. For H₂ and N₂, the results are compared with corresponding measurements for H⁺ scattering where the interaction mechanism is quite different. In the case of CO₂, vibrational excitation in forward scattering is caused primarily by the long-range dipole interaction. The spectra are very similar for H^?-CO₂ and H⁺-CO₂. Finer details are attributed to the influence of transient charge transfer and valence interactions.     

On the additivity of atomic and molecular dipole properties and dispersion energies using H,N, O,H2, N2, O2, NO,N2O,NH3 and H2O as models

The zeroth-order theory of intermolecular forces is used to derive additivity relations for rotationally averaged molecular dipole properties and dispersion energy constants by assuming that a molecule is comprised of non-interacting atoms or molecules. Some of the additivity rules are new and others, for example the mixture rule for dipole oscillator strength distributions (DOSDs), Bragg's rule for stopping cross sections and Landolt's rule for molecular refractivities, are well known. The additivity rules are tested by using previously constructed DOSDs and reliable values for the dipole oscillator strength sums S_k , L_k and I_k , and dispersion energy constants C ₆, for H, N, O, H₂, N₂, O₂, NO, N₂O, NH₃ and H₂O as models. It is found that additivity is generally unreliable for estimating molecular properties corresponding to k < -2. Generally for k ≥ -2 and for C ₆, and if the hydrogen molecule is used to represent the hydrogen atom in the additivity rules, the additivity relations yield results that are reliable to within ?20 per cent and the estimates improve substantially as k increases. The effects of molecule formation on DOSDs is examined by comparing the various molecular DOSDs with the sum of the DOSDs for the atoms making up the molecules. Molecule formation results in a net decrease in the amount of dipole oscillator strength for low excitation energies and a compensating net increase for higher energies in a region extending from the absorption threshold to about 100 eV. This is shown to imply that estimates of the stopping average energy I ₀, obtained by using bona fide atomic I ₀ values, are lower bounds to the correct molecular I ₀ results.     

Angular distribution of the photoelectron spectrum of CO2, COS,CS2, N2O,H2O,and H2S

The photoelectron spectra of the triatomic molecules CO₂, COS, CS₂, N₂O, H₂O, and H₂S have been measured as a function of the angle θ between the direction of the incoming photon and outgoing photoelectron. The photoelectron spectra have been measured with a double-focusing electrostatic electron spectrometer to which has been attached a chamber containing a gas discharge lamp that can be freely rotated. (The photon source used was the 21.22 eV He I resonance line). From the dependence of intensity as a function of θ the angular parameter β was determined for each ionization band observed in the photoelectron spectra. A correlation was noted between the values of β and the molecular orbitals relative to the contributions of oxygen and sulfur atomic orbitals. Individual β values were also obtained for most of the vibrational bands seen in the photoelectron spectra. In most cases the vibrational structure showed little or no change in the angular parameter for a given electronic state. In certain cases, however, such as the fourth ionization band in CS₂, CO₂, and COS, rather sizeable changes in β were observed for the different vibrational bands.     

UV absorption cross section of the molecules O2, NO,N2O,CO2, H2O,and NO2

Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 52, No. 3, pp. 455–465, March, 1990.     

A new force field for the adsorption of H2, O2, N2, CO,H2O,and H2S gases on alkali doped carbon nanotubes

The main goal of this work is the generation of a new force field data set to the interaction of several gases such as H₂, O₂, N₂, CO, H₂O, and H₂S with alkali cation-doped carbon nanotubes (CNTs) using ab initio calculations at the MP2(full)/6-311++G(d,p) level of theory. Different alkali cations including Li⁺, Na⁺_, K⁺ and Cs⁺ were used to dope in the CNT. The calculated potential energy curve for the interaction of each gas molecule with each alkali cation-doped CNTs was fitted to an analytical potential function to obtain the parameters of the potential function. A modified Morse potential function was selected for the fitting in which the electrostatic interactions has been accounted by adding the β/r term to the Morse potential. The accuracy of the calculated force field was checked via Grand Canonical Monte Carlo (GCMC) simulation of the H₂ adsorption on Li-doped graphite and Li-doped CNT. The results of these simulations were compared with the experimental measurements and the closeness of the simulation results with the experimental data indicated the accuracy of the proposed force field. The main merit of this work is the derivation of a specific force field for interaction of each of six gases with four alkali cation-doped CNT, which can be used in molecular simulation of these 24 of systems. The simulation results showed the increase of the H₂ adsorption capacity of nanotube and graphite up to 50% and 10%, respectively, due to the insertion of Li ions.     

The absorption cross sections of N2, O2, CO,NO, CO2, N2O,CH4, C2H4, C2H6 and C4H10 from 180 to 700Å

The absorption cross sections of N₂, O₂, CO, NO, CO₂, N₂O, CH₄, C₂H₄, C₂H₆, C₄H₁₀ have been measured photoelectrically in the 180–700 Å region using synchrotron radiation. The absorption cross sections in the region λ ≥ 500 Å was found to be structureless and to increase monotonically with wavelength for all gases. The positions of the structure observed in the 520–720 Å region for N₂, O₂, CO₂ and N₂O are consistent with the various Rydberg series reported by previous authors.     

Ionization energies of the N2, CO,CO2, N2O,C2H2 and SiH4 molecules calculated by universal model potential

Acta physica Academiae Scientiarum Hungaricae - A modified XαSW method with universal potential (MXαSWU) was used to calculate ionization energies of the N2, CO, CO2, N2O, C2H2 and SiH4...     

FTIR-spectra of solid O2, N2 and CO

FTIR measurements of thin films of N₂, O₂ and CO at about 20 K contain a line due to the allowed or induced fundamental transition and a broad structure shifted to higher frequencies. This phonon sideband is explainable by coupling of lattice vibrations to the molecular fundamental vibration, and mirrors the weighted one phonon density-of-states. This IR-derived density-of-states can be compared with those from other experimental studies (neutron scattering, Raman) and from theoretical models.     

Diode-laser absorption measurements of CO2, H2O, N2O, and NH3 near 2.0 μm

2 , H₂O, N₂O, and NH₃ concentrations in various flowfields using absorption spectroscopy and extractive sampling techniques. An external-cavity diode laser with a tuning range of 1.953–2.057 μm was used to record absorption lineshapes from measured transitions in the CO₂ 4ν₂ ⁰+ν₃, ν₁+2ν₂ ⁰+ν₃, and 2ν₁+ν₃ bands, H₂O ν₂+ν₃and ν₁+ν₂ bands, N₂O 2ν₁+4ν₂ ⁰, ν₂ ¹+2ν₃, 3ν₁+2ν₂ ⁰, and 4ν₁ bands, and NH₃ν₁+ν₄ and ν₃+ν₄ bands. Measured CO₂, H₂O, and N₂O survey spectra were compared to calculations to verify the HITRAN96 database and used to determine optimum transitions for species detection. Individual lineshape measurements were used to determine fundamental spectroscopic parameters including the line strength, line-center frequency, and self-broadening coefficient of the probed transition. The results represent the first measurements of CO₂, H₂O, N₂O, and NH₃ absorption near 2.0 μm using room-temperature near-IR diode lasers. Received: 12 March 1998/Revised version: 7 May 1998     

Molecular photoelectron spectroscopy at 132.3 eV: N2, CO,C2H4 and O2

The molecular photoelectron spectra of gaseous N₂, CO, C₂H₄ and O₂ were obtained using yttrium Mζ X-rays (132.3 eV). Comparison with spectra taken with MgKα₁₂ X-rays (1253.6 eV) showed the molecular orbitals derived from atomic 2p orbitals to be emphasized in the YMζ spectra. Orbital compositions were confirmed in N₂ and CO, and the presence of several peaks was either better established or detected for the first time (e.g., a ²Π_u state at 23.5 eV in O₂⁺) in C₂H₄ and O₂. The relative cross-section predictions of Rabalais et al. were tested by these spectra. The theoretical values, which were based on ground-state wavefunctions and plane-wave (PW) or OPW continuum states, were found to agree qualitatively with experiment, establishing that this level of theory has diagnostic value. Quantitative agreement is lacking, however. The potential application of 132.3 eV X-rays to the study of photoemission from adsorbed molecules on surfaces is emphasized.     

Adsorption and solution of H2, D2, N2, O2 and CO by (100) Ta

Sticking coefficients, saturation densities, and solution rates of gases on (100) Ta are obtained by comparing with results on (100) W using Auger electron spectroscopy and flash desorption. Hydrogen has a lower sticking coefficient on (100) Ta than on polycrystalline Ta, but solution occurs readily even at 78°K. Differences between H₂ and D₂ are observed for both adsorption and solution. Nitrogen is confined to the surface of Ta for T < ≈500°K, and adsorbed nitrogen dissolves with an activation energy of ≈2.5 kcal mole^?1 upon heating to higher temperatures. The saturation density of O₂ at 300° K is approximately twice that on (100) W. The first monolayer dissolves at ≈500°K but the second dissolves or desorbs only at much higher temperatures. Carbon monoxide adsorbs without solution of either species at 300°K. At ≈500°K carbon dissolves completely leaving oxygen which desorbs at much higher temperature.     

Dispersion energy constants C 6(A,B), dipole oscillator strength sums and refractivities for Li,N, O,H2, N2, O2, NH3, H2O,NO and N2O

Accurate values for the orientation-averaged long-range dipole-dipole dispersion energy coefficients, C ₆(A, B), have been determined for all possible pair interactions involving ground state H, Li, N, O, H₂, N₂, O₂, NH₃, H₂O, NO, and N₂O. The calculations have been carried out by employing dipole oscillator strength distributions for these species that have been constructed (except in the case of H) by using discrete oscillator strength, photo-absorption, and high energy inelastic scattering data and by requiring the distributions to reproduce the Thomas-Reiche-Kuhn sum rule and, in the case of the molecules, available accurate refractivity and dispersion measurements for the relevant dilute gases. These oscillator strength distributions were also used to evaluate the refractivity R(λ), as a function of wavelength λ in the visible and ultra-violet region below the ultra-violet absorption thresholds, and the dipole oscillator strength sums S _-2l , l = 1, 2, …, 7, for each atom and molecule. The calculated values of R(λ) provide refractivities for wavelengths, especially in the ultra-violet region, for which accurate experimental data are often not available. The accurate results for C ₆(A, B) and for various dipole oscillator strength sums are used to make self-consistent tests of the adequacy of (1) the C ₆(A, A) bounds provided by Padé approximant methods and (2) various semi-empirical formulae for C ₆(A, B). Some problems that can arise in using other procedures to evaluate the S _-2l and C ₆(A, B) are discussed briefly.     

基于单一量子级联激光器的大气多组分气体(CO、N2O、H2O)同时测量方法

针对海藻三维荧光光谱线性降维方法不理想、模型识别准确率低的问题,提出通过局部线性嵌入(LLE)算法进行降维、通过黄金正弦算法(Gold-SA)对支持向量机(SVM)进行优化来构建分类模型的方法。将LLE算法降维后的海藻三维荧光光谱数据作为SVM的输入,并与其他两种降维方法进行对比。结果显示：LLE算法的降维效果最好,识别准确率最高。为了进一步提高门类识别能力,采用Gold-SA对SVM进行优化并建立Gold-SA-SVM模型,再将其与其他4种分类模型进行对比。结果显示,Gold-SA-SVM模型在分类识别准确率、精准率、召回率和F1分数上都有明显提高,该方法可准确识别抑食金球藻、小球藻、细长聚球藻的门类,可为褐潮研究工作提供有效的参考。     

The oxidation of CO by O2, NO and N2O on polycrystalline platinum under knudsen conditions: A comparison

The oxidation of CO by O₂, NO and N₂O can be described by quite similar elementary reaction sequences which differ only in the way atomic oxygen is generated on the surface. This difference is sufficient to explain the observed experimental results.     

Photoelectron asymmetry parameters of Ar,Kr, Xe,H2, N2, O2, CO and CO2: New measurements and a reconsideration of literature data

The performance of the first commercially available angular-dispersive photoelectron spectrometer (ADES 400, VG Scientific Ltd.) has been improved and     

Foreign gas broadening of difluoromethane by N2, O2 and CO2

The linewidth parameters of difluoromethane broadened by N₂, O₂, and CO₂ have been measured at microwave frequencies and are compared with calculated values for dipole-quadrupole interactions by using the Murphy-Boggs theory. The observed linewidths yield reasonable values of molecular quadrupole moments.