共查询到20条相似文献,搜索用时 15 毫秒
1.
O.N. Ulenikov G.A. Onopenko E.S. Bekhtereva T.M. Petrova A.M. Solodov A.A. Solodov 《Molecular physics》2013,111(5):637-647
The combination band ν5 + ν12 of ethylene, C2H4, has been recorded for the first time with a high resolution Fourier transform spectrometer Bruker IFS 125HR. Assignments of transitions and preliminary rotational analysis are made. Two models (Hamiltonian of the isolated vibrational state and Hamiltonian that takes into account resonance interactions) are used. Influence of the local resonance interactions on the parameters and reproduction power of the models is discussed. 相似文献
2.
Fundamental spectroscopical parameters of the weak ν1+3ν2
1-ν2
1+ν3 band of CO2 are reported using a high-resolution, direct-absorption spectrometer, based on a distributed feed-back diode laser emitting
at 2 μm. Line intensities and self-broadening coefficients have been measured for the first time with high accuracy, for nine
lines of the R branch, from R(44) up to R(59). Comparison with available data has been made, and a generally good agreement
has been found.
Received: 30 August 1999 / Published online: 24 March 2000 相似文献
3.
4.
C. Corsi M. Inguscio S. Chudzynski K. Ernst F. D’Amato M. De Rosa 《Applied physics. B, Lasers and optics》1999,68(2):267-269
Sensitivity studies are also performed, to evaluate the minimum detectable concentration of HCl in air.
Received: 7 August 1998/Revised version: 5 October 1998 相似文献
5.
《Journal of Molecular Spectroscopy》1986,119(1):181-189
The vibration-rotation spectrum of CF3Cl, with natural isotopic abundance, has been recorded in the 622- to 641-cm−1 region using a tunable diode laser spectrometer. The K structure of many P(J) and R(J) manifolds of the ν1-ν3 difference band of CF335Cl has been resolved and positively identified. The rotational analysis has been extended in the P and R branches up to J = 39 and 47, respectively, and more than 650 lines have been assigned. A least-squares fit of the observed transitions to the energy expression including the quartic centrifugal distortion terms was performed and molecular constants for the ν1-ν3 difference band were determined. From the obtained parameters the ν3 band center of CF335Cl was evaluated as 476.9750(4) cm−1 and the values of α3A and α3B were derived to be 50(1) × 10−6 and 82.9(6) × 10−6 cm−1, respectively. 相似文献
6.
《Journal of Molecular Spectroscopy》1986,120(1):205-218
High-resolution diode laser spectra and medium-resolution F-T spectra of deuterated ammonia have been obtained in the 700- to 1030-cm−1 region. Out of about 800 lines measured by diode laser spectroscopy, approximately 500 lines have been assigned to the ν2 transitions of NH2D. The parameters for the ground and ν2 states of NH2D have been derived by the simultaneous analysis of the infrared and microwave data. The standard deviation for the IR data is ∼8 × 10−4 cm−1. It is shown that the energy levels of NH2D in the ν2 state are heavily perturbed by inversion-rotation interaction and that it is necessary to include higher order inversion-rotation interaction terms to obtain a satisfactory fit of the observed data. 相似文献
7.
T. Földes D. Golebiowski T.P. Softley G. Di Lonardo L. Fusina 《Molecular physics》2014,112(18):2407-2418
Jet-cooled spectra of 14NH3 and 15NH3 in natural abundance were recorded using cavity ring-down (CRDS, 6584–6670 cm?1) and cavity enhanced absorption (CEAS, 6530–6700 cm?1) spectroscopy. Line broadening effects in the CRDS spectrum allowed lines with J ″-values between 0 and 3 to be identified. Intensity ratios in 14NH3 between the jet-cooled CRDS and literature room-temperature data from Sung et al. (J. Quant. Spectrosc. Radiat. Transfer, 113 (2012), 1066) further assisted the line assignments. Ground state combination differences were extensively used to support the assignments, providing reliable values for J, K and inversion symmetry of the ground state vibrational levels. CEAS data helped in this respect for the lowest J lines, some of which are saturated in the CRDS spectrum. Further information on a/s doublets arose from the observed spectral structures. Thirty-two transitions of 14NH3 were assigned in this way and a limited but significant number (19) of changes in the assignments results, compared to Sung et al. or to Cacciani et al. (J. Quant. Spectrosc. Radiat. Transfer, 113 (2012), 1084). Sixteen known and 25 new low-J transitions were identified for 15NH3 in the CRDS spectrum but the much scarcer literature information did not allow for any more refined assignment. The present line position measurements improve on literature values published for 15NH3 and on some line positions for 14NH3. 相似文献
8.
《Journal of Molecular Spectroscopy》1986,116(1):191-213
The ν2 fundamental band of 14NH3 is observed with a laser Stark spectrometer in Doppler-limited resolution. A set of 41 constants including the electric dipole moment and its rotational dependence are determined from 360 Stark resonances observed in the present work and 67 millimeter- and submillimeter-wave inversion and rotation-inversion lines reported in the literature. The rms residual of the fit is 3.1 × 10−4 cm−1. Field-free transition frequencies of the band in the region 800–1160 cm−1 are calculated from the constants and tabulated together with their estimated uncertainties and relative absorption intensities. Rotational dependence of the electric dipole matrix elements of a C3v molecule is presented on the basis of the conventional theory of vibration-rotation. 相似文献
9.
R. R. Xu Y. Tian M. Wang L. L. Hu J. J. Zhang 《Applied physics. B, Lasers and optics》2011,102(1):109-116
A new type host of germanate glass (GeO2− BaO−BaF2−Ga2O3−La2O3) codoped with Tm2O3 has been investigated for application as laser material. It possesses a large emission cross section with the value of 9.3×10−21 cm2 at 1.8 μm. Judd-Ofelt intensity parameters and radiative transition probability are calculated and analyzed by Judd-Ofelt
theory and absorption spectra. The infrared emission spectra at 1.8 μm have been obtained by using a 794 nm laser diode as
excitation resource. The emission intensity ratio of 1.8 (3F4→3H6) to 1.47 μm (3H4→3F4) increases, while the experimental lifetime of the Tm3+:3H4 level decreases by increasing Tm2O3 concentration, which is attributed to the presence of a cross relaxation process. The most intensive emission at 1.8 μm is
achieved from the germanate glass with the concentration of Tm2O3 reaches 1.0 wt%. The extended overlap integral method is used to calculate the microparameter of the energy transfer and
the critical distance, which are derived to better understand the energy transfer process of thulium ions in the germanate
glass responsible for emission at 1.8 μm. 相似文献
10.
《Journal of Molecular Spectroscopy》1986,119(1):190-200
The infrared spectrum of the ν4 band of CH3I around 3060 cm−1 was studied at a resolution of 5.4 × 10−3 cm−1. About 1850 transitions were assigned. The K range was from KΔK = −7 to KΔK = +9 and the highest J values were about 75. The anomalous rotational structures observed in the subbands PQ6 and RQ5 – RQ7 were explained as a consequence of Coriolis and Fermi resonances with combination levels. The standard deviation of the least-squares fit with 19 parameters was 0.00083 cm−1. In addition to the fundamental band, the hot band ν3 + ν4 − ν3 was also studied. 相似文献
11.
A. Perrin J. Vander Auwera Z. Zelinger 《Journal of Quantitative Spectroscopy & Radiative Transfer》2009,110(9-10):743-755
Using high-resolution Fourier transform spectra of trans-HCOOH recorded at 5.6 μm, we carried out an extensive analysis of the strong ν3 fundamental band (carbonyl stretching mode) at 1776.83 cm?1, starting from results of a previous analysis [Weber WH, Maker PD, Johns JWC, Weinberger E. J Mol Spectrosc 1987; 121: 243–60]. As pointed out in the literature, the ν3 band is significantly perturbed by resonances due to numerous dark bands. We were able to assign series belonging to the ν5+ν7, ν5+ν9, ν6+ν7 and ν6+ν9 dark bands, located at 1843.48, 1792.63, 1737.96 and 1726.40 cm?1, respectively. The model used to calculate energy levels accounts partly for the observed resonances, and enabled us to reproduce most of the observed line positions, within their experimental uncertainties. We also determined absolute line intensities with an accuracy estimated to 15%. Finally, we generated, for the first time, a list of line parameters for the 5.6 μm region of trans-formic acid. 相似文献
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13.
《Journal of Molecular Spectroscopy》1987,126(1):129-139
Spin splittings for several important atmospheric lines in the ν3 band of NO2 have been measured by diode laser. An improved spin-splitting program has been developed which takes into account the asymmetry effects in the lower Ka splittings. The measured spin splittings and the derived spin-rotational constants are reported in this study to a much higher accuracy than previously achieved. 相似文献
14.
《Journal of Molecular Spectroscopy》1987,125(1):99-114
The spectrum of the ν1 + ν2 band of NO2 has been studied with a resolution of 0.025 cm−1. Spin-rotation constants and rotational constants are reported. An interesting perturbation has been found in the ground state of the molecule which occurs when the Ka = 0 and Ka = 2 levels become accidentally nearly degenerate around N = 42. An explanation of this interaction is presented. 相似文献
15.
Molecular absorption lines due to vibrational-rotational transitions in14NH3 are observed near 1.5 m. An InGaAsP DFB laser is frequency stabilized to a linear absorption line within 500 MHz at 1543.08 nm. Such an absolute frequency-stabilized DFB laser is useful for coherent optical system applications owing to its long-term frequency stability and for residual gas detectors. 相似文献
16.
The strong infrared absorption in the ν3 S–F stretching region of sulphur hexafluoride (SF6) near 948 cm?1 makes it a powerful greenhouse gas. Although its present concentration in the atmosphere is very low, it is increasing rapidly, due to industrial pollution. The ground state population of this heavy species is only 32% at room temperature and thus many hot bands are present. Consequently, a reliable remote-sensing spectroscopic detection and monitoring of this species require an accurate modelling of these hot bands. We used two experimental set-ups at the SOLEIL French synchrotron facility to record some difference and combination bands of SF6: (1) a new cryogenic multiple pass cell with 93 m optical path length and regulated at 163 ± 2 K temperature and (2) the Jet-AILES supersonic expansion set-up. With this, we could obtain high-resolution absorption spectra of the ν3 ? ν1, ν3 ? ν2, ν1 + ν3 and ν2 + ν3 bands at low temperature. These spectra could be assigned and analysed, thanks to the SPVIEW and XTDS computer programs developed in Dijon. We performed two global fits of effective Hamiltonian parameters. The first one is a global fit of the ground state, ν2, ν3, ν3 ? ν2, ν2 + ν3, 2ν3 and 2ν3 ? ν3 rovibrational parameters, using the present spectra and previous infrared, Raman and two-photon absorption data. This allows a consistent refinement of the effective Hamiltonian parameters for all the implied vibrational levels and a new simulation of the 2ν3 + ν2 ? ν2 hot band. The second global fit involves the present ν3 ? ν1 and ν1 + ν3 lines, together with previous ν1 Raman data, in order to obtain refined ν1 parameters and also ν1 + ν3 parameters in a consistent way. This allows to simulate the ν3 + ν1 ? ν1 hot band. 相似文献
17.
T. M. Petrova A. M. Solodov A. A. Solodov V. M. Deichuli V. I. Starikov 《Molecular physics》2018,116(10):1409-1420
The water vapour line broadening and shifting for 97 lines in the ν1 + ν2 + ν3 band induced by hydrogen pressure are measured with Bruker IFS 125 HR FTIR spectrometer. The measurements were performed at room temperature, at the spectral resolution of 0.01 cm?1 and in a wide pressure range of H2. The calculations of the broadening γ and shift δ coefficients were performed in the semi-classical method framework with use of an effective vibrationally depended interaction potential. Two potential parameters were optimised to improve the quality of calculations. Good agreements with measured broadening coefficients were achieved. The comparison of calculated broadening coefficients γ with the previous measurements is discussed. The analytical expressions that reproduce these coefficients for rotational, ν2, ν1, and ν3 vibrational bands are presented. 相似文献
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19.
C. Du S. Ruan H. Zhang Y. Yu F. Zeng J. Wang M. Jiang 《Applied physics. B, Lasers and optics》2005,80(1):45-48
We report a high-power laser-diode-array end-pumped 0.3 at.% Nd:GdVO4 continuous-wave laser operating at 1.34 m. The maximum output power of 13.3 W was obtained at the incident pump power of 49.2 W, giving the corresponding optical conversion efficiency of 27% and the average slope efficiency of 28.5%. The thermal focal length of the Nd:GdVO4 crystal under the pump power from 15.3 to 50 W was measured experimentally. PACS 42.55.Xi; 42.70.Hj 相似文献
20.
J.-M. Flaud W.J. Lafferty R.L. Sams 《Journal of Quantitative Spectroscopy & Radiative Transfer》2009,110(9-10):669-674
Using both high resolution (0.0018 cm?1) and medium resolution (0.112 cm?1) Fourier transform spectra of an enriched 34S (95.3%) sample of sulfur dioxide, it has been possible to accurately measure a large number of individual line intensities for some of the strongest of the SO2 bands, i.e. ν1, ν3 and ν1+ν3. These intensities were least-squares fitted using a theoretical model which takes into account the vibration–rotation interactions linking the upper energy levels where needed, and, in this way, expansions of the various transition moment operators were determined. The Hamiltonian parameters determined in previous analyses together with these moments were then used to generate synthetic spectra for the bands studied and their corresponding hot bands providing one with an extensive picture of the absorption spectrum of 34SO2 in the spectral domains, 8.7, 7.4, and 4 μm. 相似文献