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171.
Joachim W. Walewski Anders Elmqvist 《Journal of Quantitative Spectroscopy & Radiative Transfer》2005,91(4):415-436
In laser-assisted combustion diagnostics it is a recurring task to predict molecular transitions whose signal strength depends only weakly on variations in temperature. The signal strength is proportional to the Boltzmann fraction of the level probed and the amplitude of the absorption line profile. In the past investigations have been presented in which this task was attack by detailed numerical calculations of the temperature dependence of pertinent physical properties of the molecule. Another widely applied approach relies on an analytical formula for the Boltzmann fraction of hetero-nuclear diatomic molecules and the neglect of line shape effects. The analytical approach experiences a continuing popularity in laser-assisted combustion diagnostics, which is why we compared both approaches with each other. The objective of this comparison was to assess the accuracy of the analytical approach and to reveal its potential pitfalls. Our comparison revealed that the analytical approach suffers from mediocre accuracy, which makes it unfit for practical applications. One cause is the neglect of higher lying vibrational levels, which show a non-negligible population for typical flame temperatures. Another reason is the neglect of fine structure splitting in molecules with non-zero orbit angular momentum in the ground state. Another reason for the observed inaccuracy is the neglect of line shape effects quenching, which were found to have a significant effect on the temperature sensitivity of a line. Because of its insufficient accuracy due to both oversimplified models of the molecular energy levels and the neglect of line shape effects and quenching we discourage from applying the analytical approach and recommend the use of detailed numerical approaches that are free of the above limitations. 相似文献
172.
Bjrn Fritzell Britta Hammarberg Helge Schiratzki Stig Haglund Evert Knutsson Anders Mrtensson 《Journal of voice》1993,7(2)
From a total of 43 adductor spasmodic patients over a 10-year period, 11 underwent resection of a portion of the recurrent laryngeal nerve on one side. The initial results were excellent but a varying degree of recurrence took place in 8 patients. In 4, a reoperation was done. At the final follow-up, 2–8 years after the primary operation, 4 patients were no longer suffering from spasmodic dysphonia, another 5 were better off than before surgery, and 1 remained unchanged. Only 1 was worse off. Electromyographic findings indicated that the recurrence of symptoms was due to regeneration of the nerve fibers. 相似文献
173.
Anders Bjö rner Michelle L. Wachs 《Transactions of the American Mathematical Society》1997,349(10):3945-3975
This is a direct continuation of Shellable Nonpure Complexes and Posets. I, which appeared in Transactions of the American Mathematical Society 348 (1996), 1299-1327.
174.
Physicotechnical Institute of Low Temperatures, Ukrainian SSR Academy of Sciences. Translated from Teoreticheskaya i Matematicheskaya Fizika, Vol. 88, No. 1, pp. 72–84, July, 1991. 相似文献
175.
Anders Höglund Ann‐Christine Albertsson 《Journal of polymer science. Part A, Polymer chemistry》2008,46(21):7258-7267
The spontaneous reaction of unsaturated double bonds induced by the fragmentation of ether bonds is presented as a method to obtain a crosslinked polymer material. Poly(1,5‐dioxepan‐2‐one) (PDXO) was synthesized using three different polymerization techniques to investigate the influence of the synthesis conditions on the ether bond fragmentation. It was found that thermal fragmentation of the ether bonds in the polymer main chain occurred when the synthesis temperature was 140 °C or higher. The double bonds produced reacted spontaneously to form crosslinks between the polymer chains. The formation of a network structure was confirmed by Fourier transform infrared spectrometry and differential scanning calorimetry. In addition, the low molar mass species released during hydrolysis of the DXO polymers were monitored by ESI‐MS and MALDI‐TOF‐MS. Ether bond fragmentation also occurred during the ionization in the electrospray instrument, but predominantly in the lower mass region. No fragmentation took place during MALDI ionization, but it was possible to detect water‐soluble DXO oligomers with a molar mass up to approximately 5000 g/mol. The results show that ether bond fragmentation can be used to form a network structure of PDXO. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 7258–7267, 2008 相似文献
176.
Anders Bjarklev J rn Hedegaard Povlsen Bo Pedersen Karsten Rottwitt 《Fiber and Integrated Optics》1991,10(1):11-21
This work analyzes how the characteristics of an erbium-doped fiber amplifier (EDFA) depends on the mode distribution of 800-nm pump light. The analysis is performed by using a large-signal model of an optimally pumped erbium-doped fiber amplifier. Special attention is given to the gain degradation, and noise figures of the amplifier for co- and counterpropagating pump light. 相似文献
177.
178.
Anders K.H. Bengtsson 《Nuclear Physics B》1983,228(1):190-204
N = 1 supergravity is studied in a light-cone gauge. The non-linear transformations and the hamiltonian are constructed to order K in the coupling constant as a realization of the super-Poicaré algebra. The only input except the algebraic structure is the helicity content () and the dimensionality of the coupling constant. 相似文献
179.
180.
Anders Hallberg Arnold R. Martin Gary E. Martin Gunnar Grönberg 《Journal of heterocyclic chemistry》1984,21(6):1893-1895
13C-nmr chemical shift assignments for 5H-Indolo[1,7-ab][1]benzazepine and 6,7-Dihydro-5H-indolo-[1,7-ab][1]benzazepine, made on the basis of two-dimensional 1H-13C chemical shift correlation experiments are reported. 相似文献