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61.
In this paper, we calculate all possible null Lagrangians (null energies) for the mechanics of a distinguished class of continua,
the nematic elastomers. The calculation is done in order to help to relate different physically equivalent theories of nematic
elastomers. We discuss both local and global (hence topological) aspects of the problem.
__________
Translated from Fundamental’naya i Prikladnaya Matematika (Fundamental and Applied Mathematics), Vol. 10, No. 1, Geometry
of Integrable Models, 2004. 相似文献
62.
Raffaele Giovanelli 《Foundations of Physics Letters》1989,2(1):27-38
A longitudinally pumped dye-laser amplifier is numerically investigated for the amplification of a very low intensity signal (as low as one photon per pulse), which is easily hindered by the simultaneous amplification of spontaneous emission. From the relevant set of coupled rate equations for population and photon fluxes the spatial dependence of these quantities is accounted for. The equations are solved numerically in some significant practical situations. The results describe the dependence of the amplified-spontaneous-emission (ASE) output flux on the pumping rate, on the spectral narrowing process and on the total spontaneous emission for a pulse in the selected angular width. The performance of dye-laser amplifiers is described by the same set of equations, and the gain characteristics of such systems are analyzed as functions of the pumping rate. 相似文献
63.
Abrahão-Neto José Infanti Patrícia Vitolo Michele 《Applied biochemistry and biotechnology》1996,57(1):407-412
Applied Biochemistry and Biotechnology - The effects of pH (4.0, 4.5, or 5.0), temperature (T) (30, 35, or 40°C) and dissolved oxygen (DO) (0.2, 2.0, 4.0, or 6.0 mg O2/L) on hexokinase and... 相似文献
64.
Isolation and identification of evernine in ‘Oakmosse’ (Evernia prunastri (L. ) Ach.). A new depside, evernin ( 1 ), has been found in the lichen Evernia Prunastri (L. ) Ach. The determination of the structure and the spectral parameters of 1 , especially the 13C-NMR. spectrum, are described. 相似文献
65.
The composition of different oakmoss extracts was investigated by combined gas chromatography/mass spectrometry. A series of 38 compounds – especially phenol derivatives and monoterpenes – was identified, 22 of which have not yet been reported as constituents of oakmoss. 相似文献
66.
Proton nmr study of hydrated sodium β-alumina reveals a Pake doublet spectrum due to stationary water molecules. As the temperature is increased from -196C to 192C, linewidth changes indicate that the stationary protons sense the increasingly rapid motion of nearby sodium nuclei and other protons. The interproton spacing computed from the spectra was found to be 1.7A. 相似文献
67.
68.
69.
Toxic metal release in simple leaching tests has been studied in this paper to assess waste behaviour in realistic landfilling scenarios. The waste is a galvanic sludge, raw or cement stabilized. Six different leachants were taken into account: distilled water, CO2-saturated solution, Olsen solution, Mehlich No. 3 solution, acid or alkaline soil circulating solution. Dynamic leaching tests of different duration were used for raw and stabilized waste. The results have shown that, with the exception of Mehlich No. 3 solution, when the waste comes into contact with waters of composition similar to that of the solutions studied, the potential environmental contamination should not be of concern. 相似文献
70.
The structure of \(\hbox {d}_{0}\)-algebra is a generalization of a D-lattice. We extend to this structure the definitions of measure and submeasure, and investigate their properties. We also investigate the relationships between uniformities and measures (or submeasures). 相似文献