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71.
Munshi G Mustafa Sudhir Raniwala T Awes B Rai RS Bhalerao JG Contreras RV Gavai SK Ghosh P Jaikumar GC Mishra AP Mishra H Mishra B Mohanty J Nayak J-Y Ollitrault SC Phatak L Ramello R Ray PK Sahu AM Srivastava DK Srivastava VK Tiwari 《Pramana》2006,67(5):961-981
This is the report of Heavy Ion Physics and Quark-Gluon Plasma at WHEPP-09 which was part of Working Group-4. Discussion and
work on some aspects of quark-gluon plasma believed to have created in heavy-ion collisions and in early Universe are reported. 相似文献
72.
P. F. Heelis B. J. Parsons G. O. Phillips J. F. McKellar † 《Photochemistry and photobiology》1979,30(3):343-347
Abstract— Primary and secondary photochemical processes in oxygen-free aqueous solution have been characterised for FMN alone and in the presence of EDTA and four amino acids using nanosecond and microsecond flash photolysis and continuous photolysis techniques. The relative contributions of oneelectron and two-electron (group or hydride transfer) reactions to the deactivation of the triplet has been determined by comparing the radical concentration (560 nm) with the bleaching of the ground state (446 nm). It was concluded that one-electron reactions (hydrogen atom or electron abstraction) are the major mode of reactivity of the flavin triplet state with all the suhstrates studied.
The nature of the reactions of the flavin semiquinone radical have been studied quantitatively by microsecond flash photolysis. These secondary reactions consist of either a 'back reaction' between the flavin and substrate radicals (tryptophan or glycyl-tyrosine) or the transfer of a second electron (or hydrogen atom) from the substrate radical to the flavin radical (EDTA, methionine and possibly cysteine) to form reduced flavin and oxidised substrate. From a comparison of the quantum yields of formation of reduced flavin using 'flash' and continuous irradiation, an additional pathway for the decay of the flavin radical is suggested to occur at low light intensities in the presence of glycyl-tyrosine or histidine. 相似文献
The nature of the reactions of the flavin semiquinone radical have been studied quantitatively by microsecond flash photolysis. These secondary reactions consist of either a 'back reaction' between the flavin and substrate radicals (tryptophan or glycyl-tyrosine) or the transfer of a second electron (or hydrogen atom) from the substrate radical to the flavin radical (EDTA, methionine and possibly cysteine) to form reduced flavin and oxidised substrate. From a comparison of the quantum yields of formation of reduced flavin using 'flash' and continuous irradiation, an additional pathway for the decay of the flavin radical is suggested to occur at low light intensities in the presence of glycyl-tyrosine or histidine. 相似文献
73.
McKellar AR 《The Journal of chemical physics》2012,136(9):094305
Clusters of para-H(2) and/or ortho-H(2) containing a single carbon dioxide molecule are studied by high resolution infrared spectroscopy in the 2300 cm(-1) region of the CO(2) ν(3) fundamental band. The (H(2))(N)-CO(2) clusters are formed in a pulsed supersonic jet expansion from a cooled nozzle and probed using a rapid scan tunable diode laser. Simple symmetric rotor type spectra are observed with little or no resolved K-structure, and prominent Q-branch features for ortho-H(2) but not para-H(2). Observed rotational constants and vibrational shifts are reported for ortho-H(2) up to N = 7 and para-H(2) up to N = 15, with the N > 7 assignments only made possible with the help of theoretical simulations. The para-H(2) cluster with N = 12 shows clear evidence for superfluid effects, in good agreement with theory. The presence of larger clusters with N > 15 is evident in the spectra, but specific assignments are not possible. Mixed para- + ortho-H(2) cluster transitions are well predicted by linear interpolation between corresponding pure cluster line positions. 相似文献
74.
Oliaee JN Dehghany M Moazzen-Ahmadi N McKellar AR 《The Journal of chemical physics》2011,134(7):074310
Infrared spectra of the nitrous oxide tetramer, (N(2)O)(4), are studied in the region of the N(2)O ν(1) fundamental band (~2200 cm(-1)). The spectra are observed using a tunable diode laser to probe a pulsed supersonic jet expansion. Parallel (ΔK = 0) bands are observed for the previously observed isomer of (N(2)O)(4), which is confirmed by isotopic substitution to have an oblate symmetric rotor structure with D(2d) symmetry. A distinct new isomer of (N(2)O)(4) is observed by means of a perpendicular (ΔK = ±1) band. It has a prolate symmetric rotor structure with S(4) symmetry. These isomers represent two distinct, but almost equally favorable, ways of bringing together a pair of nonpolar N(2)O dimers to form a tetramer. It is not clear at present which one represents the true ground state. 相似文献
75.
Abusara Z Borvayeh L Moazzen-Ahmadi N McKellar AR 《The Journal of chemical physics》2006,125(14):144306
Infrared spectra of the OCS-He van der Waals complex and of OCS-He(N) clusters have been studied in the region of the OCS nu1 fundamental band using a tunable diode laser to probe a pulsed supersonic slit jet. For the complex, the spectrum of the normal isotope, 16O12C32S-4He, has been considerably extended and the 34S- and 13C-substituted forms have been recorded for the first time. The data could be analyzed satisfactorily using a conventional asymmetric rotor Hamiltonian with sextic centrifugal distortion terms. For the clusters, the 34S- and 13C-substituted forms have been observed and assigned for N = 2-7, including some transitions with higher J values than previously reported for the normal isotope, e.g., R5. The observed vibrational shifts, relative to the free OCS molecule, were very similar to those of the normal isotope, and most of the difference could be explained by simple scaling. These results constitute a subtle and precise probe of intermolecular forces and dynamical effects in a system which is of current interest for cluster studies. 相似文献
76.
The infrared spectrum of propynal, C2HCHO, is studied at high resolution (0.003 cm−1) in the range 570-640 cm−1. The relatively intense ν11 (CC-H out-of-plane bend, 693 cm−1) and ν7 (CC-H in-plane bend, 651 cm−1) fundamental bands are linked by a strong a-type Coriolis interaction. The somewhat weaker ν8 (CCO in-plane bend, 614 cm−1) fundamental has a significant Fermi-type interaction with the “dark” background state 3ν9 (∼618 cm−1). About 1400 lines are assigned and analyzed in terms of a four-state fit in order to obtain accurate band origins, rotational and centrifugal distortion parameters, and Fermi and Coriolis interaction parameters. This represents the first systematic high-resolution infrared study of propynal. 相似文献
77.
The low-lying energy levels of 18O and 18F are calculated in the harmonic oscillator shell model taking Green's velocity-dependent N-N potential as the residual interaction. It is found that the shell-model matrix elements agree substantially with those calculated by Kuo and Brown from the unrenormalized Hamada-Johnston hard-core N-N potential. It is found furthermore that Green's parameters give rather unsatisfactory agreement with the experimental spectra. It is shown that somewhat improved agreements with experiment are possible by making appropriate parameter adjustments. 相似文献
78.
The ν2 (CO stretching) vibration-rotation bands of H2CO and D2CO near 5.8 μm have been studied using the technique of laser Stark spectroscopy. The following vibrational and rotational constants have been determined:
Constant | H2CO | D2CO | Unit |
1746.011 | 1701.620 | cm?1 | |
281807.8 ± 6. | 141696.6 ± 7. | MHz | |
38608.7 ± 5. | 32068.4 ± 7. | MHz | |
33738.7 ± 3. | 25998.6 ± 10. | MHz | |
μ″ | 2.328 ± 0.006 | 2.344 ± 0.006 | Debye |
μ′ | 2.344 ± 0.006 | 2.364 ± 0.005 | Debye |