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31.
The X-ray excited optical luminescence spectrum of Pr3+ in YPO4 was investigated. In addition to the sharp line f-f transitions involving the energy levels of the 4f2 configuration of Pr3+ ion, the spectrum contains some broad groups of fluorescence lines in the ultraviolet and blue region. These groups of fluorescence are attributed to transitions from the lowest 4fI5d state at 43050 cm-1 to the 4f2 levels of the Pr3+ion in YPO4. 相似文献
32.
M R Krishnaswamy M G K Menon N K Mondal V S Narasimham B V Sreekantan Y Hayashi N Ito S Kawakami S Miyake 《Pramana》1982,19(6):525-554
The neutrino events recorded in the Kolar Gold Field Nucleon Decay detector are analysed here. It is shown that there is good
agreement between the observations and the estimates based on the intensities of atmospheric neutrinos and interaction cross-sections
of neutrinos available from accelerator experiments. In the context of the search for proton decay, we show that the low energy
(<2 GeV) neutrino events, which would provide the main background, are suppressed at thekgf site since it is situated near geomagnetic equator, where the geomagnetic cut-off rigidities are high. A comparison of the
predicted characteristics ofv-induced events with thekgf observations shows that, within the statistical accuracy of the present data, the signal due to nucleon decay stands out
distinctly within thev-induced background. 相似文献
33.
The spectra of14NS and15NS molecules are obtained in a 2450 mc./s. microwave oscillator discharge. Vibrational assignments of theβ- andγ-systems are studied in more detail. Several hitherto unrecorded bands are satisfactorily explained as belonging to higherv′,v″ levels in the Deslandres schemes of bothβ- andγ-systems. The observed isotope shifts (14NS-15NS) provide confirmatory evidence for the proposed vibrational analysis. In the case of theγ-system, thev′=2 level of the upper state appears to be strongly perturbed showing a shift of about 38 cm.?1 from the expected position. In theβ-system, the isotopic shifts in the band-heads involving thev′=0 and 1 levels of the2Δ5/2 of the upper state show small deviations from expected values. The reality of these small deviations is established beyond doubt by the occurrence of the effect on the 0–0 sub-band which exhibits the isotopic head in a wavelength direction opposite to the expected one. 相似文献
34.
Infrared and Raman spectra of D4-ortho, meta and para fluorochloro and fluorobromo benzenes are presented and assignments are given. Some of the bands of H4-p-fluorochloro benzene assigned earlier as fundamentals are shown to be due to impurities and alternate assignments are given. The observed frequencies of the H4 and D4 molecules are combined in a normal coordinate analysis to obtain a 33-parameter modified valence force field, for the in-plane vibrations, with an average difference of ±0.8% between observed and calculated frequencies. The normal coordinate analysis shows that many of the previous assignments of the ring modes ν1, ν6, and ν12 for disubstituted benzenes are not very reliablie. Revised assignments with good correlation with the corresponding benzene modes are given. 相似文献
35.
A telescope of area 4 m2, consisting of horizontal layers of plastic scintillators, neon flash tubes and absorbers was operated at a depth of 754
hg/cm2 in the Kolar Gold Mines. New values for the vertical intensities of muons have been obtained from observations of the angular
distribution over the slant depths ∼ 750–2300 hg/cm2 and are compared with the existing measurements. From the angular distribution observed, we conclude that muons are produced
wholly through the decay of pions and kaons up to energies of the order of 1 TeV. A value of 0.3±0.2 is estimated for theK/π ratio at production, for muon energies around 500 GeV. A decoherence distribution has been obtained for parallel muon events
up to distances of the order of 10 m. From this we conclude that the averageP
t of the parents of muons of energy ∼ 250 GeV is of the order of 0.3 GeV/c. From an analysis of rock showers, we obtain the
cross section for inelastic interaction of muons of mean energy 100 GeV as (3.8±1.5)×10−30 cm2/nucleon. 相似文献
36.
For a stationary autoregressive model of order s, the partial autocorrelation coefficients of order , =0,1,2,…,s?1, are defined; the partial autocorrelation coefficient of order zero being the same as the autocorrelation coefficient of order one. Denoting these s parameters by ?1,π1,…,πs?1, it is shown that their sample images, namely r1,1,…,s?1, are asymptotically independently normally distributed with means equal to the corresponding population values and asymptotic variances given by , where n is the size of the sample from the autoregressive process of order s. The partial correlogram of the model and application of the result are discussed. 相似文献
37.
The dc and ac conductivities of glasses of the system GeSbSe (with the general formula GexSb10Se90?x have been studied. The dc conductivity results indicate a maximum in the glass transition temperature and activation energy and a minimum in conductivity for the composition Ge25Sb10Se65. These results have been explained on the basis of the prevalent structural arrangement wherein structural units of GeSe2 and Sb2Se3 are dispersed among excess Se or Ge. Based on this picture, a model has been developed which accounts for the observed dependence of conductivity on composition at any temperature. The ac results have been utilized to find the hopping conductivity as a function of composition; the characteristics of lone pair amorphous semiconductors seem to account for the observed features. 相似文献
38.
T.K. Balasubramanian G.L. Bhale M.N. Dixit N.A. Narasimham 《Journal of Molecular Spectroscopy》1981,88(2):259-263
Fluorescence was excited in the B3Πu(0+)-X1Σg+ system of diatomic iodine by means of the 5145-Å line of an Ar+ laser and the 6328-Å line of a HeNe laser. The resulting spectrum was recorded on a SPEX double monochromator and a quantitative measurement of the intensities was carried out. The variation of the electronic transition moment with R centroid observed by us shows a behavior similar to what has been reported earlier. 相似文献
39.
High-resolution spectra of the 0–9, 0–10 and 0–11 bands of theA
2II
u
—X
2II
g
system of (16O18O)+ ion have been studied for their rotational structure. This study enables a direct determination of the Λ-doubling parameters
of theA
2II
u
andX
2II
g
states. The model of ‘pure precession’ explains, though not entirely, the Λ-doubling of theX
2II
a
state as arising out of its interaction with theB
2
Σ
g
− state. The Λ-doubling in theA
2II
u
state was found insignificant. 相似文献
40.