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1.
The spectra of hydrogen-oxygen and acetylene-oxygen flames have been recorded on a Fourier transform spectrometer in the region 6200–9100 cm-1 with a resolution of 0·015 cm-1. In this region, we have performed a detailed analysis of the 2v 2 + v 3, v 1 + v 3, v 1 + v 2 + v 3 - v 2 and v 1 + v 2 + v 3 bands. A primary motive for this study was to obtain higher rotational energy levels for the (021), (101) and (111) vibrational states. Moreover an extensive set of rotational levels of the (010) vibrational state has been deduced from the combined study of hot bands involving the (011), (021) and (111) vibrational states. A room-temperature absorption spectrum of water recorded on a Fourier transform spectrometer in the region 1750–2300 cm-1 (resolution 0·005 cm-1) has also been used to confirm the analysis. 相似文献
2.
We have extended to higher N and to Ka = 3 and 4 the rotational analysis of the 7390-Å band of NO2 performed by K. E. Hallin and A. J. Merer (Canad. J. Phys.55, 2101–2112 (1977)). The lines belong to a perturbed parallel band for which Hallin and others have proposed the vibrational assignment (2 13 1)-(0 0 0) within the electronic ground state. These authors presumed that this band borrows its intensity through a vibronic coupling (spin-orbit and/or Coriolis coupling) from the stronger (0 2 0)-(0 0 0) band of the electronic system at 7460 Å. We have observed about 900 transitions belonging to the Ka = 0, 1, 2, 3, 4 subbands of the (2 13 1)-(0 0 0) band for N values going up to about 23, and 300 lines of the “hot” band (2 13 1)-(0 1 0). We have also looked for spin-orbit-induced transitions and we have detected about 400 transitions with ΔN ≠ ΔJ. Among them ΔN = ±2 transitions with ΔKa = 0 or ± 2 have been observed, indicating that N and Ka are no longer good quantum numbers, and demonstrating clearly the existence of rovibronic interactions perturbing the upper levels of the transitions. 相似文献
3.
A Hamiltonian taking explicitly into account both Fermi and Coriolis interactions has been set up for triatomic molecules of symmetry Cs and used to reproduce, very satisfactorily, the available rotational energy levels of the {(100), (020)} interacting states of HDO, providing us with realistic wavefunctions as well as precise rotational constants and vibrational energies. Then, to calculate line intensities, these wavefunctions were used together with suitably chosen transition moment operators expanded up to degree 2 in and having the correct symmetry in the Cs group, leading to hybrid bands of both A and B type., Using this formalism, it has been possible to determine, from the fit of the existing experimental intensities, the coefficients appearing in the expansions of the transition moment operators of the 2ν2 and ν1 bands of HDO. In this way, we have improved upon the F-factor formalism which needs much more parameters to reproduce the line intensities with the same precision. Finally, using the transition moments as well as the wavefunctions and energy levels deduced from the diagonalization of the Hamiltonian matrix, we have calculated the whole spectrum of the ν1 and 2ν2 bands of HDO. 相似文献
4.
Dawber M Lichtensteiger C Cantoni M Veithen M Ghosez P Johnston K Rabe KM Triscone JM 《Physical review letters》2005,95(17):177601
Artificial PbTiO3/SrTiO3 superlattices were constructed using off-axis rf magnetron sputtering. X-ray diffraction and piezoelectric atomic force microscopy were used to study the evolution of the ferroelectric polarization as the ratio of PbTiO3 to SrTiO3 was changed. For PbTiO3 layer thicknesses larger than the 3-unit cell SrTiO3 thickness used in the structure, the polarization is found to be reduced as the thickness is decreased. This observation confirms the primary role of the depolarization field in the polarization reduction in thin films. For the samples with ratios of PbTiO3 to SrTiO3 of less than one, a surprising recovery of ferroelectricity that cannot be explained by electrostatic considerations was observed. 相似文献
5.
A. Perrin J.-M. Flaud A. Valentin C. Camy-Peyret H. Gbaguidi 《Journal of Molecular Spectroscopy》2000,200(2)
Using 0.002 cm−1 resolution Fourier transform absorption spectra of an 17O-enriched ozone sample, an extensive analysis of the ν3 band together with a partial identification of the ν1 band of the 17O16O17O isotopomer of ozone has been performed for the first time. As for other C2v-type ozone isotopomers [J.-M. Flaud and R. Bacis, Spectrochim. Acta, Part A 54, 3–16 (1998)], the (001) rotational levels are involved in a Coriolis-type resonance with the levels of the (100) vibrational state. The experimental rotational levels of the (001) and (100) vibrational states have been satisfactorily reproduced using a Hamiltonian matrix which takes into account the observed rovibrational resonances. In this way precise vibrational energies and rotational and coupling constants were deduced and the following band centers ν0(ν3) = 1030.0946 cm−1 and ν0(ν1) = 1086.7490 cm−1 were obtained for the ν3 and ν1 bands, respectively. 相似文献
6.
Mäki JM Tuomisto F Varpula A Fisher D Khan RU Martineau PM 《Physical review letters》2011,107(21):217403
We have developed a method called optical transient positron spectroscopy and apply it to study the optically induced carrier trapping and charge transfer processes in natural brown type IIa diamond. By measuring the positron lifetime with continuous and pulsed illumination, we present an estimate of the optical absorption cross section of the vacancy clusters causing the brown color. The vacancy clusters accept electrons from the valence band in the absorption process, giving rise to photoconductivity. 相似文献
7.
J.?M.?L’HermiteEmail author V.?Blanchet A.?Le?Padellec B.?Lamory P.?Labastie 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2004,28(3):361-366
This paper describes the spectroscopy of Na3F both in the frequency and time domains. The photoionization efficiency curve shows two thresholds, associated to two isomers. The excited electronic states of the C2v isomer have been probed by photodepletion spectroscopy, and the results are used to analyze a time-resolved study of photoexcited Na3F, probed by photoionization. The pump-probe signal clearly shows damped oscillations, the period of which is fitted to
fs, close to twice the previously measured bending mode of Na2F [1], while the relaxation time is
fs.Received: 31 October 2003, Published online: 6 January 2004PACS:
36.40.Qv Stability and fragmentation of clusters - 33.50.-j Fluorescence and phosphorescence; radiationless transitions, quenching (intersystem crossing, internal conversion) 相似文献
8.
Study of the decay B0(B- 0)-->rho+rho-, and constraints on the Cabibbo-Kobayashi-Maskawa angle alpha
Aubert B Barate R Boutigny D Couderc F Gaillard JM Hicheur A Karyotakis Y Lees JP Tisserand V Zghiche A Palano A Pompili A Chen JC Qi ND Rong G Wang P Zhu YS Eigen G Ofte I Stugu B Abrams GS Borgland AW Breon AB Brown DN Button-Shafer J Cahn RN Charles E Day CT Gill MS Gritsan AV Groysman Y Jacobsen RG Kadel RW Kadyk J Kerth LT Kolomensky YG Kukartsev G LeClerc C Lynch G Merchant AM Mir LM Oddone PJ Orimoto TJ Pripstein M Roe NA Ronan MT Shelkov VG Wenzel WA Ford K Harrison TJ Hawkes CM 《Physical review letters》2004,93(23):231801
Using a data sample of 89 x 10(6) Upsilon(4S)-->BB decays collected with the BABAR detector at the PEP-II asymmetric B Factory at SLAC, we measure the B0(B (0))-->rho(+)rho(-) branching fraction as [30+/-4(stat)+/-5(syst)]x10(-6) and a longitudinal polarization fraction of f(L)=0.99+/-0.03(stat)+0.04-0.03(syst). We measure the time-dependent-asymmetry parameters of the longitudinally polarized component of this decay as C(L)=-0.17+/-0.27(stat)+/-0.14(syst) and S(L)=-0.42+/-0.42(stat)+/-0.14(syst). We exclude values of alpha between 19 degrees and 71 degrees (90% C.L.). 相似文献
9.
Aubert B Barate R Boutigny D Couderc F Gaillard JM Hicheur A Karyotakis Y Lees JP Tisserand V Zghiche A Palano A Pompili A Chen JC Qi ND Rong G Wang P Zhu YS Eigen G Ofte I Stugu B Abrams GS Borgland AW Breon AB Brown DN Button-Shafer J Cahn RN Charles E Day CT Gill MS Gritsan AV Groysman Y Jacobsen RG Kadel RW Kadyk J Kerth LT Kolomensky YG Kukartsev G LeClerc C Lynch G Merchant AM Mir LM Oddone PJ Orimoto TJ Pripstein M Roe NA Ronan MT Shelkov VG Wenzel WA Ford K Harrison TJ Hawkes CM 《Physical review letters》2004,93(8):081802
We measure the branching fraction for the flavor-changing neutral-current process B-->X(s)l(+)l(-) with a sample of 89x10(6) Upsilon(4S)-->BBmacr; events recorded with the BABAR detector at the PEP-II e(+)e(-) storage ring. The final state is reconstructed from e(+)e(-) or micro(+)micro(-) pairs and a hadronic system X(s) consisting of one K+/- or K(0)(S) and up to two pions, with at most one pi(0). We observe a signal of 40+/-10(stat)+/-2(syst) events and extract the inclusive branching fraction B(B-->X(s)l(+)l(-))=(5.6+/-1.5(stat)+/-0.6(exp syst)+/-1.1(model syst))x10(-6) for ml(+)(l(-))>0.2 GeV/c(2). 相似文献
10.
Aubert B Barate R Boutigny D Couderc F Gaillard JM Hicheur A Karyotakis Y Lees JP Tisserand V Zghiche A Palano A Pompili A Chen JC Qi ND Rong G Wang P Zhu YS Eigen G Ofte I Stugu B Abrams GS Borgland AW Breon AB Brown DN Button-Shafer J Cahn RN Charles E Day CT Gill MS Gritsan AV Groysman Y Jacobsen RG Kadel RW Kadyk J Kerth LT Kolomensky YG Kukartsev G LeClerc C Levi ME Lynch G Mir LM Oddone PJ Orimoto TJ Pripstein M Roe NA Ronan MT Shelkov VG Telnov AV Wenzel WA Ford K Harrison TJ Hawkes CM 《Physical review letters》2004,93(6):061801
We measure the branching fraction for the charmless semi-inclusive process B --> eta'Xs, where the eta' meson has a momentum in the range 2.0 to 2.7 GeV/c in the upsilon4S center-of-mass frame and Xs represents a system comprising a kaon and zero to four pions. We find B(B --> eta'Xs) = [3.9 +/- 0.8(stat) +/- 0.5(syst) +/- 0.8(model)] x 10(-4). We also obtain the Xs mass spectrum and find that it fits models predicting high masses. 相似文献