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31.
Abstract We analyze mathematical models governing planar flow of chemical reaction from unburnt gasesto burnt gases in certain physical regimes in which diffusive effects such as viscosity and heat conduction aresignificant. These models can be then formulated as the Navier-Stokes equations for exothermically reactingcompressible fluids. We first establish the existence and dynamic behavior, including stability, regularity, andlarge-time behavior, of global discontinuous solutions of large oscillation to the Navier-Stokes equations withconstant adiabatic exponent γ and specific heat C_v. Our approach for the existence and regularity is to combinethe difference approximation techniques with the energy methods, total variation estimates, and weak conver-gence argumeots to deal with large jump discontinuities; and for large-time behavior is an a posteriori argumentdirectly from the weak form of the equations. The approach and ideas we develop here can be applied to solvinga more complicated model where γ 相似文献
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A method is presented to measure linear dichroic triplet-minus-singlet absorbance difference spectra using absorbance-detected magnetic resonance of the triplet state in zero magnetic field. Orientational selection is achieved by using a linearly-polarised microwave field. The microwave-induced change in the absorbance of light with the electric vector parallel or perpendicular to the microwave field vector is monitored using a Morvue photoelastic modulator and an analyzing polarizer. The method is applied to reaction centres of the photosynthetic bacterium Rhodopseudomonas viridis. 相似文献
35.
E. Lund P. Hoff K. Aleklett O. Glomset G. Rudstam 《Zeitschrift für Physik A Hadrons and Nuclei》1980,294(3):233-240
The delayed neutron emission probability(P n) has been measured for79-83Ga,87-89Br,92-96Rb127-132In134,135Sb137-139I and141 -145Cs, by means of sources produced at the OSIRIS isotope separator at Studsvik. The half-life determinations of127, 129, 132In have been improved. 相似文献
36.
Absorbance-detected magnetic resonance (ADMR) of the light-harvesting complex LHC II of spinach revealed two triplet contributions, having differentD values, but equalE value (|E|=0.00379 cm?1). The two triplets are assigned to two of the three carotenoids present in LHC II: lutein (|D|=0.03853 cm?1) and neoxanthin (|D|=0.04003 cm?1). The ADMR-detected Triplet-minus-Singlet (T—S) optical difference spectrum of the carotenoid (Car) triplet transition of LHC II showed, apart from bands in the Car absorption region, a contribution in the chlorophyll (Chl) absorption region due to a change in interaction between lutein and Chla at 670 nm, and neoxanthin and Chla at 670 and 677 nm. From Linear Dichroic (LD-)ADMR-detected LD-(T—S) spectra we have determined that the tripletz-axis (which corresponds roughly to the polyenal axis) of lutein and neoxanthin makes an angle of 47° and 38° with theQ y transition moment of their adjacent Chla molecules, for the Chls absorbing at 670 and 677 nm, respectively. TheT z triplet magnetic transition moment of lutein is parallel to the lutein singlet and triplet absorptions, whereas theT x axis of neoxanthin makes an angle of about 20 degrees with the optical transition moments of the carotenoid molecule. The major Chla absorption bands of the optical absorption spectrum and the ADMR-detected T—S spectrum is best explained by assuming that all Chla is present in dimers. It is proposed that a free Chl dimer absorbs at 664 and 670 nm, whereas a Chl dimer bound to a carotenoid absorbs at 670 and 677 nm. 相似文献
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David Hoff 《Journal of Differential Equations》1980,38(1):1-31
We construct by finite differences solutions of the Cauchy problem for the nonlinear wave equation in one space dimension. We make certain monotonicity assumptions about the initial data, and we show that the resulting solution is Lipschitz continuous for positive times. In addition, we prove the uniqueness of the solution in a certain class, and we characterize its large-time behavior in terms of the equilibrium state for a corresponding Riemann problem. Finally, we show how our results can be extended to more general 2 × 2 systems of hyperbolic conservation laws which are genuinely nonlinear. 相似文献
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The decay of isotope-separated 121Ag has been studied. A level scheme for 121Cd has been constructed. Information on lifetimes of excited states has been obtained by the method of delayed coincidences. Some low-lying energy levels of 121Cd show a considerable deviation from the systematics of similar levels in the lighter isotopes of Cd. This may be attributed to a different spatial symmetry of 121Cd. 相似文献
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F. Hoff 《Optics Communications》1979,30(2):159-162
The indices for characterizing the performance of holographic recording media introduced recently by Tai and Yu can be related to the parameters of the optimal linear transfer function (OLTF). These parameters have been obtained in an analytical form by the author for the recording material with an exponential transfer curve and for the holographic setup using two plane waves and for the case of the fourier lensless hologram. The expressions for the indices in terms of the OLTF parameters are given and their geometrical meaning in relation to the OLTF is pointed out for the two holographic setups mentioned. 相似文献