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1.
A mathematical analysis of the Bjerrum function is carried out. This function arises from the Stepwise Equilibrium Model, which is used to describe successive complex formation in systems consisting of free metal ion, free ligand, and all theML
i
complexes that can form in solution. The appropriate root of the Bjerrum polynomial allows the determination of the concentrations of all species present in solution, given the initial concentrations of metal and of ligand, and the equilibrium constants governing the system. It is proved that there is only one positive root of the Bjerrum polynomial, and thus that only a single equilibrium state can exist. It is also shown that the positive root of the Bjerrum polynomial can be reliably obtained by Newton's method, but only if the initialization point is properly chosen, and that the initial concentrationL of ligand is the optimum such point. Finding this root is a calculation that typically must be carried out at each iteration in nonlinear least squares procedures for determining equilibrium constants. Finally, the necessary mathematical analysis is carried out to determine the optimum initial concentrations of metal and lgand which maximize the resulting concentration of a particularML
i
complex. 相似文献
2.
Abstract— C18 formate ester (5) [2-(6-methyl-8-(2,6,6-trimethyl-1-cyclohexen-1-yl)-3E,5E,7E-octatrienyl formate], a highly reactive analog of retinal, was synthesized and its interaction with bacterioopsin studied. The formate ester, in the absence of purple or bleached membrane, undergoes very rapid reaction (tl/2 = 0.9 min) in neutral buffer but with membrane present it diffuses more rapidly into the membrane where it reacts slowly. Incorporation of 5 in the membrane results in a 38 nm (3900 cm-1 ) red shift which remains after reconstitution with retinal. Similar experiments with the corresponding C18 alcohol (4) results in a red shift, but this absorption blue shifts upon reconstitution with retinal. Washing the formate ester-treated membrane with bovine serum albumin or the corresponding lyophilized preparation with hexane, treatments that remove retinal oxime, fails to remove the UV-visible absorption, suggesting that a covalent bond between the C18 moiety and a nucleophilic group of the protein has probably formed. 相似文献
3.
Andrew J. Birnbaum Heungsoo Kim Nicholas A. Charipar Alberto Piqué 《Applied Physics A: Materials Science & Processing》2010,99(4):711-716
A laser forward transfer technique for the simultaneous printing of polymer/metal stacked micro-laminates is introduced. Several
different material combinations as well as stacking architectures are presented including single laser pulse deposited dual
layer capacitors, three-layer stacks for potentially printing organic thin-film transistors (OTFTs), and photo-definable polymer/metal
laminates and free-standing membranes for MEMS based sensors. 相似文献
4.
A study of the fluorescence spectra of fly ash samples from different sources has shown that each samples has a characteristic fluorescence and excitation spectrum which could be used to identify and monitor its presence. Fluorescence lifetime studies of samples from different sources have demonstrated characteristic features which can be used for identification. The fluorescence method should be useful for in situ and remote monitoring applications. 相似文献
5.
Collision-induced absorption in the translation-rotation band of H2 and H2-He mixtures has been measured from 20 to 900 cm-1 at 77.4, 195 and 292 K. To establish the accuracy of the results, various sources of error are investigated. The zeroth and first spectral moments are evaluated from experiment and theory for H2 at the various temperatures. To obtain theoretical moments consistent with the experimental values, the quantum pair-distribution function must be used. The major portion of the experimental moments can be accounted for by quadrupole-induced dipoles in H2 pairs. The remaining portion is attributable to an anistropic overlap interaction, although its magnitude depends on the value of the molecular parameters required to calculate the quadrupole contribution. 相似文献
6.
S. M. Edmonds N. Birnbaum G. H. Walden und L. P. Hammett 《Fresenius' Journal of Analytical Chemistry》1941,122(5-6):215
Ohne Zusammenfassung 相似文献
7.
Bulk superconducting samples of type Tl0.5Pb0.5Sr1.6Ba0.4CaCu2−x
Ru
x
O7−δ, (Tl, Pb)/Sr-1212, with 0.0 ≤ x ≤ 0.525 were prepared by the conventional one-step solid-state reaction technique. The prepared samples were investigated
using X-ray powder diffraction, electrical resistivity and electron paramagnetic resonance (EPR) measurements. Enhancement
of the phase formation, superconducting transition temperature T
c and hole carriers concentration P was observed up to x = 0.075. For x > 0.075, a reverse trend was observed. EPR spectra were measured at different temperatures (120–290 K) for all prepared samples.
The number of spins N participating in the resonance and the paramagnetic susceptibility χ were calculated as a function of both Ru-content and
temperature. N and χ increased as the Ru-content increased. A linear relationship between logN and 1/T was established, from which the activation energy E
a was calculated as a function of the Ru-content. The temperature dependence of χ was fitted according to Curie–Weiss type
of magnetic behavior. Curie constant C, Curie temperature θ, the effective magnetic moment μ and the electronic specific heat γ were estimated as a function of the Ru-content. 相似文献
8.
This review focuses on major trends in nanoparticle-based pseudostationary phase (PSP) CEC since the publication of our previous reviews within nanoparticle-based CEC [Nilsson, C., et al., Electrophoresis 2006, 27, 76-83; Nilsson, C., et al., J. Chromatogr. A 2007, 1168, 212-224.]. Special attention is given to the development toward protein analysis, which is driven by the strong emergence of protein drug development in the pharmaceutical industry. Furthermore, we discuss the development in coupling different detection techniques with nanoparticle-based PSP CEC, which were originally predicted to be particularly cumbersome. However, at present, direct UV, LIF and ESI-MS have been used without any severe complications. Different types of nanoparticles used as PSP during the period include gold nanoparticles, carbon nanostructures and lipid-based nanoparticles. New materials (for example, different types of carbon nanostructures and self assembled lipid-based nanostructures) are a strong driving force for development in separation science. Finally, future trends in nanoparticles-based CEC are envisioned. 相似文献
9.
10.
The phonon density of states of substoichiometric polycrystalline Pd-H(D) was investigated by Raman Scattering above and below the 50 K anomaly. The Raman spectra for hydrogen and deuterium were found to be asymmetric and peaked at 58.5 meV and 39.7 meV respectively, in near agreement with inelastic neutron scattering data. The scattering mechanism appears to require hydrogen-hydrogen interactions. No major changes in the optical spectra were observed in going through the 50 K anomaly. 相似文献