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51.
A radiochemical procedure is given for the simultaneous determination of low levels of129I, actinides (Pu, Am, Cm) and90Sr in vegetation samples. It is shown that grass samples up to 5 kg fresh weight can be wet ashed conveniently by hydrogen peroxide under alkaline conditions, subsequent to an initial enzymatic disintegration. After purification of the iodine fraction,129I is determined by neutron activation analysis. Using alpha spectrometry,238Pu and239,240Pu are determined in the plutonium fraction, and241Am,242Cm, and244Cm in the americium/curium fraction. The90Sr is determined after separation by beta counting its decay product90Y. 相似文献
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Lu L Rininsland FH Wittenburg SK Achyuthan KE McBranch DW Whitten DG 《Langmuir : the ACS journal of surfaces and colloids》2005,21(22):10154-10159
Herein we describe studies that indicate a cationic conjugated polyelectrolyte shows biocidal activity against gram-negative bacteria (Escherichia coli, E. coli, BL21, with plasmids for Azurin and ampicillin resistance) and gram-positive bacterial spores (Bacillus anthracis, Sterne, B. anthracis, Sterne). These studies were carried out with aqueous suspensions of the conjugated polyelectrolyte, with the polyelectrolyte in supported formats and with samples in which the conjugated polyelectrolyte was coated on the bacteria. The results are interesting in that the biocidal activity is light-induced and appears effective due to the ability of the conjugated polyelectrolyte to form a surface coating on both types of bacteria. The effects observed here should be general and suggest that a range of conjugated polyelectrolytes in different formulations may provide a useful new class of biocides for both dark and light-activated applications. 相似文献
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Palmer F Stingel C Tünnemann R Mack HG Jung G Hoffmann V 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2004,60(8-9):1739-1750
The interaction of cyclic peptides with surface-bound model peptides was investigated by ATR-FTIR spectroscopy, principal components analysis and force field calculations. Information about the interacting functional COOH, COO-, and NH3+ groups and the peptide backbone was gained through a set of cyclohexapeptides (seven of the type c(X1KX2KX3K) (K = L-lysine) and one of the type c(X1KX2KX3k) (k = D-lysine), which are interacting with L-arginine- or tripeptide-coated Si-ATR crystals. All measurements were performed in aqueous solutions. Spectra evaluation in the range 1800-1500 cm(-1) was done by band and principal components analysis (PCA). Only adsorbed molecules were present in these spectra. The coatings were investigated by ATR-FTIR spectroscopy too in order to characterise their functional groups. Based on this knowledge, the spectra of the interacting partners could be evaluated in relation to cyclohexapeptides and coatings. As a result, it was possible to identify the distinct differences in the bonding behaviour of the various peptides. 相似文献
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Frauke Sprengel 《Numerical Algorithms》2001,26(2):111-121
We propose some algorithms to solve the system of linear equations arising from the finite difference discretization on sparse grids. For this, we will use the multilevel structure of the sparse grid space or its full grid subspaces, respectively. 相似文献
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Frauke Zbikowski 《Nachrichten aus der Chemie》2006,54(11):1078-1079
Chemie‐Nobelpreisträger George A. Olah hat in seiner Heimatstadt Budapest seine Vorstellungen einer Zeit «beyond oil and gas» präsentiert. Seine «Methanol Economy» nutzt den C1‐Alkohol als Stoff, der Öl ersetzen könnte. Die Nachrichten haben nachgefragt. 相似文献
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Simone Steig Frauke Cornelius Andreas Heise Rutger J. I. Knoop Gijs J. M. Habraken Cor E. Koning Henning Menzel 《Macromolecular Symposia》2007,248(1):199-206
A double-headed initiator was synthesized yielding two functional groups for the initiation of the nickel mediated ring-opening polymerization of γ-benzyl-L -glutamate-N-carboxyanhydride and controlled radical polymerization of vinyl monomers via ATRP or NMP. Well-defined block copolymers combining polypeptides and synthetic polymers were obtained. 相似文献
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