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1.
In the 1B2u-1Ag system of naphthalene in a supersonic jet, rotational contour calculations show rotational temperatures of 2–60 K for argon carrier gas pressures of 1520-120 Torr. The b1u vibration v24 shows a high vibrational temperature which corresponds to the seeding temperature for pressures <400 Torr. 相似文献
2.
Cumulant functions are introduced to describe the statistical state of a radiation field. These functions are simply related
to the optical coherence functions but have some interesting features. It is shown that if the cumulant functions of all orders
greater than some numberN
0 vanish then they also vanish for all orders greater than 2. Thermal field is the only field having this property. This property
holds whether the field is described by a classical stochastic process or by a quantum density operator. Further the particular
operator ordering used in defining these cumulant functions for the quantized field affects only the second order cumulant
function. To describe the statistical state of a vector field such as partially polarized or unpolarized radiation, one would
need to introduce cumulant tensors. 相似文献
3.
4.
Using the technique of computer simulation of rotational band contours the 1–0 band in v 7, band E, in the 5000 Å 1 B 1g -1 Ag system of p-benzoquinone has been rotationally analysed. It is a type A band and the excited state rotational constants are: The excited state inertial defect determined from these constants is -0·8 ± 0·2 uÅ 2. This value is almost certainly due not to non-planarity of the excited state but to a Coriolis interaction between v 7 and perhaps the b 1u vibration v 13. Such an interaction, if it were weak, would affect only the A′ rotational constant. Previous assignments [2] of other type A bands and type B bands in the spectrum are reviewed where possible with the new evidence of the computed contours and the assignments remain largely unaltered. 相似文献
5.
The origin band of the 2760 å system of p-chlorofluorobenzene has been shown to be a type B band of a prolate asymmetric top. The electronic assignment of the system is therefore 1 B 2-1 A 1. The excited state rotational constants are: compared with the estimated ground state constants: The rotational origin of the band is at 36275·1 ± 0·2 cm-1. 相似文献
6.
7.
A. D. Frawley G. M. Crawley C. L. Hollas 《Zeitschrift für Physik A Hadrons and Nuclei》1978,286(3):307-311
Excitation functions of proton elastic and inelastic scattering on58Ni have been measured for proton energies in the range 17.1 to 20.6 MeV, at laboratory angles of 90°, 120° and 155°. All show cross section fluctuations. Excitation functions are presented for the elastic and for five inelastic groups in the energy range 18.1 to 18.59 MeV. These were analyzed by the Fourier analysis method, and the average level width found to be about 13 keV. The observation of strong fluctuations in the higher inelastic yields has implications for several microscopic analyses reported in the literature of58Ni(p, p′) data obtained at 17.7 MeV incident proton energy. 相似文献
8.
T.R. Gilson J.M. Hollas E. Khalilipour J.V. Warrington 《Journal of Molecular Spectroscopy》1978,73(2):234-239
The molecule styrene-β-D2 has been prepared. The liquid-phase infrared spectrum in the region 400 to 3500 cm?1 and the laser Raman spectrum have been recorded. Vibrational assignments for this molecule have been made largely by comparison with those of Condirston and Laposa (2) for C6H5CHCH2, C6H5CDCD2, C6D5CHCH2, and C6D5CDCD2. 相似文献
9.
MA Freitas CL Hendrickson AG Marshall 《Rapid communications in mass spectrometry : RCM》1999,13(15):1639-1642
We present a novel approach for the determination of activation energy for the unimolecular dissociation of a large (>50 atoms) ion, based on measurement of the unimolecular dissociation rate constant as a function of continuous-wave CO(2) laser intensity. Following a short ( approximately 1 s) induction period, CO(2) laser irradiation produces an essentially blackbody internal energy distribution, whose 'temperature' varies inversely with laser intensity. The only currently available method for measuring such activation energies is blackbody infrared radiative dissociation (BIRD). Compared with BIRD, FRAGMENT: (a) eliminates the need to heat the surrounding ion trap and vacuum chamber to each of several temperatures (each requiring hours for temperature equilibration); (b) offers a three-fold wider range of effective blackbody temperature; and (c) extends the range of applications to include initially cold ions (e.g., gas-phase H/D exchange). Our FRAGMENT-determined activation energy for dissociation of protonated bradykinin, 1.2 +/- 0.1 eV, agrees within experimental error to the value, 1.3 +/- 0.1 eV, previously reported by Williams et al. from BIRD experiments. Copyright 1999 John Wiley & Sons, Ltd. 相似文献
10.
The system of 1,3-difluorobenzene has been observed using the technique of two-photon fluorescence excitation obtained with a pulsed dye laser. Calibration was achieved by a combination of the neon optogalvanic spectrum and etalon fringes. In circular, compared to linear, polarization the bands divide into two groups, those which are B2-A1 and which retain their intensity with circular polarization, and those which are A1-A1 and lose about 60% of their intensity under the same conditions. These two kinds of bands also show characteristic rotational contours. All of the A1-A1 bands whose assignments are established obtain their intensity through vibronic interaction in which the vibration ν′25 (ν′14 in the Wilson numbering) mixes the with, presumably, the state. There is an important Fermi resonance between the 91 and 101111 levels. Parts of the one-photon absorption spectrum have been photographed to identify sequences associated with the 000 band for comparison with those observed in the two-photon spectrum, and to search for bands involving odd quanta of b2 vibrations, including ν′25 (ν′14); none was found. 相似文献