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61.
Münchow G Schönfeld F Hardt S Graf K 《Langmuir : the ACS journal of surfaces and colloids》2008,24(16):8547-8553
We present a detailed study of the diffusive transport of proteins across a fluid phase boundary within aqueous two-phase systems. The aim of the work is to investigate whether local effects at the phase boundary cause a retardation of the diffusive transport between the phases. Possible modifications of interfacial mass transfer could be due to protein adsorption at the phase boundary or local electric fields from electric double layers. Experiments with a microfluidic system have been performed in which protein diffusion (bovine serum albumin and ovalbumin) within a bilaminated configuration of two phases containing polyethylene glycol and dextran is analyzed. A one-dimensional model incorporating phase-specific diffusion constants and the difference in chemical potential between the phases has been formulated. A comparison of experimental and simulation data shows a good overall agreement and suggests that a potential local influence of the phase boundary on protein transport is insignificant for the systems under investigation. 相似文献
62.
Xu Y Brereton RG Trebesius K Bergmaier I Oberzaucher E Grammer K Penn DJ 《The Analyst》2007,132(7):638-646
A newly devised fuzzy metric for measuring the dissimilarity between two planar chromatographic profiles is proposed in this paper. It does not require an accurately assigned sample-feature matrix and can cope with slight imprecision of the positional information. This makes it very suitable for 1-D techniques which do not have a second spectroscopic dimension to aid variable assignment. The usefulness of this metric has been demonstrated on a large data set consisting of nearly 400 samples from Denaturing Gradient Gel Electrophoresis (DGGE) analysis of microbes on human skin. The pattern revealed by this dissimilarity metric was compared with the one represented by a sample-feature matrix and highly consistent results were obtained. Several pattern recognition techniques have been applied on the dissimilarity matrix based on this dissimilarity metric. According to rank analysis, within-individual variation is significantly less than between-individual variation, suggesting a unique individual microbial fingerprint. Principal Coordinates Analysis (PCO) suggests that there is a considerable separation between genders. These results suggest that there are specific microbial colonies characteristic of individuals. 相似文献
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Volker Weinrich Kurt Polborn Christian Robl Karlheinz Sünkel Wolfgang Beck 《无机化学与普通化学杂志》2000,626(3):706-716
Hydrocarbon‐bridged Metal Complexes. L Dicarbonyl Cyclopentadienyl Pyridoyl Iron Complexes as Ligands Dicarbonyl‐cyclopentadienyl‐2‐ and 3‐pyridoyl‐iron (L1, L2) and 2,6‐dicarbonyl‐pyridine‐bis(dicarbonyl‐cyclopentadienyl‐iron) (L3) function as ligands in metal complexes and the N,O‐chelates [(OC)4M(L1)] (M = Mo, W, 8 a, b ) and [(Ph3P)2Cu(L1)]+BF4– ( 9 ) were prepared. Monodentate coordination of L1 and L2 through the pyridine N‐atom occurs in the palladium(II) complexes [Cl2Pd(PnBu3)(L1)] ( 10 ), [Cl2Pd(PnBu3)(L2)] ( 11 ) and [Cl2Pd(L2)2] ( 12 ). Ligand L3 forms the O,N,O‐bis(chelate) [Cl2Zn(L3)] ( 13 ). The crystal and molecular structures of L1, 8 b (M = W), 9–11 and 13 were determined by X‐ray diffraction. 相似文献
65.
Wolfgang von Rybinski Karlheinz Hill 《Angewandte Chemie (International ed. in English)》1998,37(10):1328-1345
A new generation of nonionic surfactants that are widely applicable and simultaneously ecologically compatible has been developed in the alkyl polyglycosides. Their production from the renewable resources glucose and fatty alcohol and their ultimate biodegradation into carbon dioxide, water, and assimilated bacterial biomass is an example for a closed cycle. As a result of their physico-chemical properties and ecotoxicological evaluation, they have become very important as high-performance components of detergents and cosmetic preparations. 相似文献
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Martin Ziegler Karlheinz Ochs Mirko Hansen Hermann Kohlstedt 《Applied Physics A: Materials Science & Processing》2014,114(2):565-570
In nature, the capability of memorizing environmental changes and recalling past events can be observed in unicellular organisms like amoebas. Pershin and Di Ventra have shown that such learning behavior can be mimicked in a simple memristive circuit model consisting of an LC (inductance capacitance) contour and a memristive device. Here, we implement this model experimentally by using an Ag/TiO2?x /Al memristive device. A theoretical analysis of the circuit is used to gain insight into the functionality of this model and to give advice for the circuit implementation. In this respect, the transfer function, resonant frequency, and damping behavior for a varying resistance of the memristive device are discussed in detail. 相似文献
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70.
Karlheinz Grö chenig Michael Leinert 《Journal of the American Mathematical Society》2004,17(1):1-18
We prove non-commutative versions of Wiener's Lemma on absolutely convergent Fourier series (a) for the case of twisted convolution and (b) for rotation algebras. As an application we solve some open problems about Gabor frames, among them the problem of Feichtinger and Janssen that is known in the literature as the ``irrational case'.