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Absorption spectra are reported for a number of metalloporphyrins in n-octane. For ZnP and PdP, sharp quasi-lines with linewidths ≈4 cm?1 are observed at 15 and 35 K, respectively. The narrowest linewidths for PtP are ≈12 cm at 15 K, while NiP and CuP show no quasi-linear structure. In these latter cases, quasi-linewidth is attributed to electronic radiationless decay of the visible excited state. The various vibronic bands within Q(1, 0) are tabulated. The quasi-line structures for several zinc porphyrins at 77 K are also reported. Generally, these are not as sharp as those found in ZnP; in particular, Zn tetraphenyl porphin shows no quasi-linear structure. In these cases, the quasi-line structure is attributed to inhomogeneous broadening. 相似文献
105.
E. Gadioli E. Gadioli-Erba P. Guazzoni P. E. Hodgson L. Zetta 《Zeitschrift für Physik A Hadrons and Nuclei》1984,318(2):147-155
Several early studies of the (p, α) reaction to discrete states of the final nucleus indicated that it proceeds mainly by the pick-up mechanism, whereas more recent experiments provide qualitative arguments in favour of the knock-out mechanism. This paper reports calculations showing that the angular distributions and analysing powers of the90,92Zr(p, α)87,89Y and118Sn(p, α)115In reactions can be equally well fitted by distorted wave calculations using either mechanism. 相似文献
106.
[(C5HR4)PCl2] ( 1a ), [(C5HR4)PBr2] ( 1 b ), [(C5HR4)AsCl2] ( 2 ), and [(C5HR4)SbCl2] ( 3 ), have been obtained from the corresponding pnicogen trihalides and sodium tetraisopropylcyclopentadienide (R = CHMe2). The molecular structures of 1, 2 , and 3 as well as the related structure of [(C5HR4)BiCl2] ( 4 ) display increasing π character of hetero atom to cyclopentadienyl bonding with increasing metallic character of the hetero atom. 相似文献
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108.
Murray Hodgson 《Applied Acoustics》1983,16(5):369-391
Measurements are presented of the sound absorption of two factory machines. Their third octave absorption, between 160 Hz and 5 kHz, is in the range 0.5–2.6 m2.Measurements of reverberation time (RT) and/or sound propagation (SP) in four factories with panel roofs, when empty and/or fitted, are also presented. The general characteristics of RT and SP in such factories, and the factors that influence them, are discussed in the light of the results. Fittings reduce the RT and large-distance SP levels in proportion to their volume density and to the absorption of the panel roof. Levels near a source can increase due to backscattering. Preferentially orientated fitting arrangements do not significantly affect the variation of SP with direction in a factory.The effect of roof pitch on factory SP is complicated. Large distance levels are generally lowest in the direction across the roof pitches. 相似文献
109.
Alkoxychlorofluorocyclopropanes are easily prepared by chlorofluorocarbene addition to en-ethers in a two-phase system and converted by simple heating in an aqueous solvent mixture to 2-fluoro-2-alkenals which can be reduced to the corresponding alcohols. 相似文献
110.