排序方式: 共有16条查询结果,搜索用时 0 毫秒
11.
RUI P. BONIFÁCIO EDUARDO J. M. FILIPE CLARE McCABE MARGARIDA F. COSTA GOMES AGÍLIO A. H. PÁDUA 《Molecular physics》2013,111(15):2547-2553
The solubility of xenon in n-hexane and n-perfluorohexane has been studied using both molecular simulation and a version of the SAFT approach (SAFT-VR). The calculations were performed close to the saturation line of each solvent, between 200 K and 450 K, which exceeds the smaller temperature range where experimental data are available in the literature. Molecular dynamics simulations, associated with Widom's test particle insertion method, were used to calculate the residual chemical potential of xenon in n-hexane and n-perfluorohexane and the corresponding Henry's law coefficients. The simulation results overestimate the solubility of xenon in both solvents when simple geometric combining rules are used, but are in good agreement if a binary interaction parameter is included. With the SAFT-VR approach we are able to reproduce the experimental solubility for xenon in n-hexane, using simple Lorentz-Berthelot rules to describe the unlike interaction. In the case of n-perfluorohexane as a solvent, a binary interaction parameter was introduced, taken from previous work on (xe + C2F6) mixtures. Overall, good agreement is obtained between the simulation, theoretical and experimental data. 相似文献
12.
Lebaupain F Salvay AG Olivier B Durand G Fabiano AS Michel N Popot JL Ebel C Breyton C Pucci B 《Langmuir : the ACS journal of surfaces and colloids》2006,22(21):8881-8890
Detergents are customarily used to solubilize cell membranes and keep membrane proteins soluble in aqueous buffers, but they often lead to irreversible protein inactivation. Hemifluorinated amphiphiles with hybrid hydrophobic chains have been specifically designed to minimize the denaturating propensity of surfactants toward membrane proteins. We have studied the physical-chemical and biochemical properties of lactobionamide surfactants bearing either a hydrogenated, a fluorinated or a hemifluorinated chain (respectively H-, F-, and HF-Lac). We show that the dual composition of the hydrophobic chain of HF-Lac endows it with unusual physical-chemical properties as regards its critical micellar concentration, interfacial area per molecule, and behavior upon reverse phase chromatography. Analytical ultracentrifugation shows that, whereas H-Lac assembles into well-defined micelles, F-Lac and HF-Lac form large and heterogeneous assemblies, whose size increases with surfactant concentration. Molecular dynamics calculations suggest that F-Lac forms cylindrical micelles. The ability of HF-Lac to keep membrane proteins soluble was examined using the cytochrome b(6) f complex from Chlamydomonas reinhardtii's chloroplast as a model protein. HF-Lac/b(6) f complexes form particles relatively homogeneous in size, in which the b(6) f complex is as stable or markedly more stable, depending on the surfactant concentration, than it is in equivalent concentrations of hydrogenated surfactants, including H-Lac. 相似文献
13.
14.
It is known that a Markov map T of the unit interval preservesa measure µ, say, equivalent to Lebesgue measure, andthat almost every point of the interval has a forward orbitunder T that is uniformly distributed with respect to µ.In the opposite direction the main result of this paper statesthat there is a set of points having Hausdorff dimension 1 whoseforward orbits are in a certain sense very far from being sodistributed. 1991 Mathematics Subject Classification: 58F08,28A80. 相似文献
15.
16.