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41.
42.
M. R. DE BACKER-BARILLY A. BARBE S. A. TASHKUN VL. G. TYUTEREV A. CHICHERY 《Molecular physics》2013,111(22):3499-3506
The four 5v 3 bands of 18O enriched ozone have been observed and analysed for the first time. Two species (16O18O16O and 18O16O18O) belong to the C2v symmetry group and two other (18O18O16O and 16O16O18O) to the Cs symmetry group. They have been recorded at a resolution of 0.008 cm?1 with a pathlength of 32.16 m. Despite the very weak absorptions observed, almost 250 energy levels have been derived for each of the 4 species, with J ? 35 and K a ? 13, and suitable sets of Hamiltonian parameters have been determined. For 3 species it has been necessary to account for the resonance between the (005) and (311) states to correctly reproduce the spectra observed. These resonances, anharmonic for C2v, and hybrid (both anhar-monic and Coriolis) for Cs symmetry confirm the accidentally extremely strong coupling between the (005) and (311) states for 16O3, due in that case to the very close distance between unperturbed energy levels. This work also confirms the excellent prediction of band centres of these four species derived from the recently determined isotopically invariant molecular potential function. 相似文献
43.
JOSE PITARCH-RUIZ JOSE SANCHEZ-MARIN ALFREDO SANCHEZ DE MERAS DANIEL MAYNAU 《Molecular physics》2013,111(3):483-494
The vertical electronic spectrum of formaldehyde has been studied by means of (SC)2-MR-SDCI and CCLR methods. Two basis sets of atomic natural orbitals (ANOs) complemented with a one-centre series of Rydberg orbitals were used. The first was taken from the CASPT2 study by Merchán, M., and Roos, B. O., 1995, Theoret. Chim. Acta, 92, 221, and may be described as C,O[4s3pld]/H[2slp] with a lslpld Rydberg series centred in the charge centroid of the 2B2 state of the cation. The second was a larger basis set that may be described as C,O[6s5p3d2f]/H[4s3p2d] + 3s3p3d in the same centre. The (SC)2 dressing may be applied efficiently to an MR-SDCI method and comparison with the dressed CAS-SDCI is satisfactory, in spite of the remarkable reduction in the CI space dimension. The consistency of the (SC)2-MR-SDCI results was tested also against the CCLR and CASPT2 results using the same basis sets and against the CCLR results using Dunning's aug- and daug-cc-pVQZ basis sets. The 3A1(π → π *) state is correctly placed as the second excited triplet while the highly multi-configurational nature of the 1A1(π → π *) state is confirmed as well as its greatly mixed valence-Rydberg nature. This state is predicted as lying under the 10 eV level, on top of the (ny → 3d) Rydberg states that are predicted in the 8.9–9.5eV region. The 5 1B2(ny → 4s) Rydberg state and the 1B2(σy → π*) also are predicted in this region. The triplet states also were calculated with the (SC)2-MR-SDCI method. The vertical ordering of the 2 1A1(ny → 3py) and 2 1B2(ny → 3pz) states is discussed, as well as that of the 1B1(σ → π*) and the Rydberg 1B1(ny → 3dxy) states. This work shows the highly reliable values that may be reached applying the dressing method along with a large basis set. Such a procedure is made possible using an MR-SDCI selection of spaces instead of the CAS-SDCI that was used up to now in most (SC)2 dressing applications. 相似文献
44.
The composition-independent virial coefficients of a d-dimensional binary mixture of (additive) hard hyperspheres following from a recent proposal for the equation of state of the mixture (Santos, A., Yuste, S. B., and López de Haro, M., 1999, Molec. Phys., 96, 1) are examined. Good agreement between theoretical estimates and available exact or numerical results is found for d = 2, 3, 4 and 5, except for mixtures whose components are very disparate in size. A slight modification that remedies this deficiency is introduced and the resummation of the associated virial series is carried out, leading to a new proposal for the equation of state. The case of binary hard sphere mixtures (d = 3) is analysed in some detail. 相似文献
45.
46.
Multiconfigurational perturbation theory (CASPT2) and difference dedicated configuration interaction (DDCI) are applied to study the ferrimagnetic coupling in an oxamido-bridged Mn(II)Cu(II) molecular species. CASPT2 reproduces the experimental coupling very well. From the partition of the CASPT2 energy, the most important contributions to the coupling are established. Spin populations are calculated with DDCI. The successive improvement of the N-electron wave function allows us to analyse the contributions to the spin delocalization. 相似文献
47.
BARB FLORIN DAN; DE KONING WILLEM L.; IONESCU VLAD 《IMA Journal of Mathematical Control and Information》1995,12(3):253-298
This paper represents a Popov-theory-based assessment of thecurrent status of the digital control of infinitedimensionalsystems with certain unboundedness in control and/or observation,summarizing some results and indicating which, in the authors'opinion, would be the promising directions for future research. 相似文献
48.
This paper deals with robustness of adaptive control of continuoussystems subject to known output delay, input saturation, unmodelledlinear dynamics, and bounded disturbances. A simple gradient-typealgorithm with a relative deadzone is used. The relative deadzoneis built with an estimated contribution of the unmodelled dynamicsto the system output. The basic tool used for stability androbustness analysis is Gronwall's lemma. 相似文献
49.
Auditory correlates of perceived mallet hardness for a set of recorded percussive sound events 总被引:1,自引:0,他引:1
D J Freed 《The Journal of the Acoustical Society of America》1990,87(1):311-322
A psychophysical investigation of timbre was undertaken with the intent of deriving quantitative results that could be useful in musical applications. Recordings of metal objects being struck with percussion mallets were rated by subjects on a unidimensional perceptual scale of perceived mallet hardness. Four acoustical parameters of the attack portion (first 325 ms) were defined and evaluated as predictors of perceived mallet hardness rating. To measure these parameters, a critical-band filter bank was employed. Two curves were extracted from the filter-bank output: (1) spectral level (log of area under spectrum) over time, and (2) spectral centroid over time. For each curve, two parameters were measured: the mean and the slope of the spectral level curve, and the mean and the time-weighted average of the spectral centroid curve. Multiple regression analysis was used to relate the perceptual ratings to these four acoustical parameters, and a good fit was achieved (multiple R-squared = 0.725, F = 1135.8, p less than 0.01). The resulting function is suitable for quantitatively predicting the perceptual dimension of perceived mallet hardness. 相似文献
50.