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41.
Mahmoud Mollabashi R. M. Lees J. W. C. Johns 《International Journal of Infrared and Millimeter Waves》1993,14(9):1727-1753
The Fourier transform far-infrared (FTFIR) spectrum of CD3OH has been obtained from 40–220 cm–1 at a resolution of 0.002 cm–1, and partially analyzed. Numerousb-type branches have been assigned in the spectrum, ranging over torsional states fromn=0 to 3. The branches have been fitted toJ(J+1) power-series energy expansions in order to obtainJ-independent branch origins. These in turn have been fitted to the torsion-rotation Hamiltonian, and improved molecular constants have been obtained for the ground vibrational state. 相似文献
42.
Abstract— Evidence is presented for the formation of a thymine hydrate upon ultraviolet (UV) or gamma irradiation of aqueous solutions. The UV quantum efficiency exhibits a dependence on pH similar to that shown for uracil hydration, but the yield is three orders of magnitude smaller than for uracil. Hydration is not affected by wavelength, oxygen, or concentration of thymine. The reversal rate of the photohydrate to thymine is similar to the reversal rates of both isomers of the thymine hydrate formed by γ radiolysis, and depends on pH in the same way as the rate for the uracil photohydrate. The photohydrate of thymine is chromatographically identical to the cis isomer of 6-hydroxy-5, 6-dihydrothymine. 相似文献
43.
44.
C. Bréchignac J.W.C. Johns A.R.W. McKellar M. Wong 《Journal of Molecular Spectroscopy》1982,96(2):353-361
The ν2 fundamental band of H2CO has been studied using a combination of sub-Doppler laser Stark spectroscopy and Doppler-limited Fourier transform spectroscopy. A combined analysis of the Stark and Fourier infrared data together with previous microwave data on the ν2 = 1 state yielded improved molecular parameters for formaldehyde, including the excited state dipole moment. A small perturbation was noted at K′a = 7 which may be ascribed to a ΔKa = 2 interaction with the v3 = 1 state. Precise treatments of ν2 with K′a > 6 will thus require a combined analysis taking into account Coriolis interactions among ν4, ν6, ν3, and ν2. 相似文献
45.
High-resolution Fourier transform spectroscopy has been applied to confirm previously proposed assignments for nine far infrared (FIR) laser lines from the CH3-deformation state of CH3OH and one line from the CH3-rocking state. Accurate frequencies are deduced for the observed and other predicted FIR laser transitions. FIR torsional branch frequencies in the ground state which were used in the confirmation are presented. Comments are also made on the OH-bending mode of CH3OH. 相似文献
46.
47.
Synthesis and reactions of 5 ,8-epidioxyandrost-6-enes 总被引:1,自引:0,他引:1
W F Johns 《The Journal of organic chemistry》1971,36(17):2391-2397
48.
49.
B. Johns 《国际流体数值方法杂志》1982,2(3):253-261
A finite-difference method is described for the numerical integration of the one-dimensional shallow water equations over a sloping shelf that allows for a continuously moving shoreline. An application of the technique is made to the propagation of non-breaking waves towards the shoreline. The results of the computation are compared with an evaluation based upon an exact analytical treatment of the non-linear equations. Excellent agreement is found for both tsunami and tidal scale oscillations. 相似文献
50.
Studies on the basic fraction from Ipomoeamuricata Jacq. seeds, grown in Senegal, resulted in the isolation of two hexahydroindolizine alkaloids, the previously described ipalbidine and a new alkaloid, ipomine, C30H35NO8, the structure of which is established as 1-β-ipalbidinyl-4-p-coumaroyl-d-glucopyranoside. 相似文献