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51.
Normal coordinate analysis for XY4 type molecules of T
symmetry has been carried out by the Wilson F — G matrix method. Following Dennison and making use of the spectral data the anharmonicity factors for B'H
4
–
, B'D
4
–
, B10H
4
–
and B10D
4
–
have been calculated and potential constants have been evaluated for borohydride isotopic ions. 相似文献
52.
The peak, integrated and standard intensities of some prominent Raman lines in twelve alcohols are estimated. The standard intensities of the lines due to some characteristic bonds in various alcohols are compared and large variations observed. 相似文献
53.
The paramagnetic resonance spectrum of Gd3+ in Pr(NO3)3·6H2O single crystals, is studied at room temperature. A seven line spectrum for H//Z as well as for H//X corresponding to ΔM=±1 transitions is observed along with a number of low field transitions (ΔM?2). The spin-Hamiltonian analyses is presented. 相似文献
54.
A. Sivaram H. Jagannath D.Ramachandra Rao Putcha Venkateswarlu 《Journal of Physics and Chemistry of Solids》1979,40(12):1007-1018
The steady state and transient fluorescence spectra of CaF2: Dy3+ have been studied using Ar+ and N2 lasers in the temperature range 77–673 K and in the wavelength region 4500–9000 Å. The spectra show the presence of two types of centers (type A and type B) with decay times of 1.3 and 3.5 ms. The observed spectrum is mostly due to type A centers. Three new groups of fluorescence 4F9/2−6H11/2, 4F9/2−(6H9/2, 6F11/2) and 4F9/2−(6H7/2, 6F9/2) have been observed for type A centers, and a tentative assignment of the positions of the Stark levels of 6H11/2, (6H9/2, 6F11/2) and (6H7/2, 6F9/2) has been made. The change in the intensity of the transitions with temperature and excitation wavelength are discussed. 相似文献
55.
56.
57.
Taxifolin (a dihydro flavonol) and a procyanidin have been isolated from the stem bark ofRhododendron grande Wight. It is of special interest that they represent neighbouring stages in the biogenetic evolution of polyphenols. The procyanidin occurs as a dimer for which probable structures are proposed based upon chemical and spectral evidence. This dimer represents a new type. 相似文献
58.
Putcha Venkateswarlu 《Hyperfine Interactions》1985,24(1-4):203-221
The infrared and millimeter wave spectroscopy, laser Stark spectroscopy, and beam maser spectroscopy of CH3CN and its isotopic species will be discussed. The beam maser spectroscopy and hyperfine structure of molecules like NCCCD,
ClCCD and CH3CCH are reviewed. The laser magnetic resonance and hyperfine structure in CF, CH and CH2 free radicals will be discussed. The Lamb dip spectroscopy and laser-induced fluorescence in I2 involving theB
3Π(0
u
+
) state are reviewed with special reference to its hyperfine structure. The splitting of the rotational levels of N
2
+
in itsX
2Σ
g
+
andB
2Σ
u
+
states due to hyperfine interactions (along with the hyperfine structure) in laser-induced fluorescence in theB−X transition is discussed. Recent results obtained in the laser photo-acoustic spectrum of ICl in the transitionX
1Σ+ −A
3Π1 will be presented and the possibility of the use of this technique in studying the hyperfine structure will be discussed. 相似文献
59.
An impurity mediated mechanism of photorefractive effect in BaTiO3 is proposed. The photoinduced changes in the relative concentration of Fe3+ in BaTiO3 results in an electro-optic coupling through a combination of the Sangster and piezoelectric effects. This is based on the
examination of the extensive results on the EPR of Fe3+ in the BaTiO3 lattice. This model explains the improved photorefractive behavior of BaTiO3 on doping with Co2+. 相似文献
60.