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71.
Szabó L Herman K Leopold N Buzumurgă C Chiş V 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2011,79(1):226-231
The surface-enhanced Raman scattering (SERS) spectra of Eriochrome Black T (EBT) and its Cu(II), Fe(III), Mn(II) and Pb(II) complexes were recorded using a hydroxylamine reduced silver colloid. Molecular geometry optimization, molecular electrostatic potential (MEP) distribution and vibrational frequencies calculation were performed at B3LYP/6-31G(d) level of theory for the EBT molecule and its Cu(EBT), Fe(EBT) and Mn(EBT) metal complexes. Differentiation between EBT complexes of Cu(II), Fe(III), Mn(II) and Pb(II) is shown by the SERS spectral features of each complex. 相似文献
72.
The on-line detection of emulsion polymerization processes by means of solid-state NMR spectroscopy is demonstrated for the
first time using poly(butyl acrylate) as a model system. Relatively short time intervals are accessible via 1H detection while the use of 13C NMR spectroscopy results in an increased spectral resolution. Details of sample preparation and experimental techniques
are given, while remaining artifacts of the preliminary results will be addressed in further investigations.
Received: 7 November 1997 Accepted: 5 January 1998 相似文献
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75.
H. Erdmann H. Mennicke G. Romijn A. Fernau L. Spiegel Adrian und Ed. Schaer 《Fresenius' Journal of Analytical Chemistry》1902,41(11):703-706
Ohne Zusammenfassung 相似文献
76.
Several groups have reported using a method of limiting the field of view (FOV) where the slices excited by the 90 and 180 degree pulses are perpendicular. However, only one slice can be excited during each repetition time, so multislice imaging is not possible. We present a modification of this method that allows multislice imaging. The slices excited by the 90 degrees and 180 degrees pulses are at a small angle; the field of view is limited and multislice imaging is possible. The modifications also allow the center of the FOV to be offset to any position. We describe the conditions that yield optimal images for the given FOV, slice thickness, and interslice gap. Representative images demonstrating the features of the technique are presented. The technique can be used to reduce the number of phase-encoding steps resulting in reduced imaging time, or it can be used to increase the spatial resolution without increasing the imaging time. 相似文献
77.
78.
Leopold Halpern 《General Relativity and Gravitation》1977,8(8):623-630
A gravitational law is proposed on a De Sitter covariant space. Dirac's De Sitter covariant spinning electron equation is generalized to the presence of gravitational fields. The resulting equation differs from the generally covariant Dirac equation by a mass renormalization. The last result is a generalization of that of Gürsey and Lee [2] in case of the homogenous De Sitter metric, and it gives a wider outlook on the significance of this result from the point of view of gauge theory.Dedicated to Achille Papapetrou on the occasion of his retirement. 相似文献
79.
Archiv der Mathematik - 相似文献
80.