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461.
462.
Experimental Mechanics - Shape memory alloys (SMAs) are phase transforming materials featuring strong thermomechanical couplings. Infrared thermography and heat source reconstruction (HSR) enable... 相似文献
463.
Gustavo Amadeu Micke Ana Carolina O. Costa Melina Heller Michelle Barcellos Marcel Piovezan Thiago Caon Marcone Augusto Leal de Oliveira 《Journal of chromatography. A》2009,1216(45):7957-7961
The aim of this study was to develop a fast capillary electrophoresis method for the determination of propranolol in pharmaceutical preparations. In the method development the pH and constituents of the background electrolyte were selected using the effective mobility versus pH curves. Benzylamine was used as the internal standard. The background electrolyte was composed of 60 mmol L−1 tris(hydroxymethyl)aminomethane and 30 mmol L−1 2-hydroxyisobutyric acid, at pH 8.1. Separation was conducted in a fused-silica capillary (32 cm total length and 8.5 cm effective length, 50 μm I.D.) with a short-end injection configuration and direct UV detection at 214 nm. The run time was only 14 s. Three different strategies were studied in order to develop a fast CE method with low total analysis time for propranolol analysis: low flush time (Lflush) 35 runs/h, without flush (Wflush) 52 runs/h, and Invert (switched polarity) 45 runs/h. Since the three strategies developed are statistically equivalent, Wflush was selected due to the higher analytical frequency in comparison with the other methods. A few figures of merit of the proposed method include: good linearity (R2 > 0.9999); limit of detection of 0.5 mg L−1; inter-day precision better than 1.03% (n = 9) and recovery in the range of 95.1–104.5%. 相似文献
464.
Microwave-enhanced reactions are very fast in comparison to thermal reactions. The determination of optimal end point often fails because conventional analytical methods are too slow. Therefore, we established a fast method using FTIR spectroscopy. The result of the reaction control analysis is obtained within less than 1 min. 相似文献
465.
Michael?Heller Leszek?Pysiak Wies?aw?Sasin Zdzis?aw?Golda 《General Relativity and Gravitation》2009,41(7):1625-1637
Heller et al. (J Math Phys 46:122501, 2005; Int J Theor Phys 46:2494, 2007) proposed a model unifying general relativity and
quantum mechanics based on a noncommutative algebra defined on a groupoid having the frame bundle over space–time as its base space. The generalized Einstein equation is assumed
in the form of the eigenvalue equation of the Einstein operator on a module of derivations of the algebra . No matter sources are assumed. The closed Friedman world model, when computed in this formalism, exhibits two interesting
properties. First, generalized eigenvalues of the Einstein operator reproduce components of the perfect fluid energy-momentum
tensor for the usual Friedman model together with the corresponding equation of state. One could say that, in this case, matter
is produced out of pure (noncommutative) geometry. Second, owing to probabilistic properties of the model, in the noncommutative
regime (on the Planck level) singularities are irrelevant. They emerge in the process of transition to the usual space–time
geometry. These results are briefly discussed. 相似文献
466.
467.
468.
D. Schulze W. Heller H. Ullrich H. Kupsch C. Segebade 《Journal of Radioanalytical and Nuclear Chemistry》1993,168(2):385-392
Because of incresing problems due to the general non-acceptance of the application of open radioactivity in modern industrial research an investigation was made concerning the possibility of replacing radiotracers by inactive substances activated by photons after sampling. As an example, investigations in the glass-processing industry was selected. The results were confirmed by the radiotracer experiment performed in parallel. The data obtained were in good agreement. 相似文献
469.
Siegfried Heller 《Mathematische Annalen》1911,71(2):299-302
Ohne Zusammenfassung 相似文献
470.
Spectral polarization features of the macroscopic manifestation of parity violation in gaseous media
Yu. I. Heller 《Optics and Spectroscopy》2006,100(2):152-163
A formalism based on macroscopic Maxwell equations is developed for the case of media with violations of the space symmetry and time reversal. It is demonstrated that the parity violation in a medium is equivalent to the manifestation of spatial dispersion and natural optical activity. The proposed formalism makes it possible to uniquely calculate the macroscopic parameters of equations in terms of the microscopic theory. The parameters of gyrotropy and dichroism of a gaseous medium are determined within a model describing an interaction of resonance radiation with transitions to states that have different parities and are mixed by a weak interaction of an electron with the nucleus of the atom. It is established that, in the range of the resonance with a magnetic dipole transition, the effect of parity violation is enhanced as a result of the considerable difference between the natural broadenings of the electric and magnetic dipole transitions. This enhancement is suppressed when the dominant Doppler broadening of the atomic transitions is taken into account. It is shown that, owing to the unitarity of the weak interaction, the effects of parity violation are alternating functions of the radiation frequency and are integrally absent in the entire spectrum. 相似文献