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131.
132.
Interactions between the diblock copolymer S15E63 and the surfactant sodium dodecyl sulfate (SDS) have been investigated by isothermal titration calorimetry (ITC) in the temperature range 10–40°C. At 20°C, the block copolymer is associated into micelles with a hydrodynamic radius of 11.6?nm, which is composed of a hydrophobic styrene oxide (S) core and a water-swollen oxypolyethylene (PEO) corona. The copolymer/surfactant system has been studied at a constant copolymer concentration of 0.25?wt% and over a wide range of surfactant concentration, from 7.5?×?10?6 up to 0.3?M. The titration calorimetric data for SDS in the temperature range 10–20°C presents a first endothermic increase indicating the formation of mixed copolymer rich-surfactant micelles. From that point, important differences in the ITC plots for surfactant titrations in the presence and in the absence of the copolymer are present. A shallow second endothermic peak is assigned to the interaction between SDS molecules and copolymer molecules resulting from the beginning of micelle disruption. An exothermic peak indicates the end of this disruption where only SDS micelles attached to single copolymer monomers are present, as shown by DLS in a previous paper. At higher temperatures in the range 25–40°C, the first endothermic maximum is not totally shown because interactions between surfactant and block copolymer start at very low SDS concentrations. Moreover, the second endothermic peak is absent and the exothermic minimum is less pronounced as a consequence of the increased micellization of the block copolymer. 相似文献
133.
134.
The distribution equilibria of cobalt(II) with 4-methyl-N-8-quinolinylbenzene sulphonamide in the presence of tributylphosphate or trioctylphosphine oxide dissolved in toluene were studied as a function of hydrogen ion concentration and the concentration of the organophosphorus compounds. Evaluation of the extraction data made it possible to deduce the stoichiometry of the extracted species, determine their corresponding extraction constants and quantify the synergic effect. 相似文献
135.
136.
We claim that physics has been constructed because three “philosophical” principles have been respected, namely, realism,
locality, and consistency. These principles lead to an interpretation of quantum mechanics (QM) in terms of local hidden-variables
theories (LHV). In order to prove that LHV have not been refuted, we analyze the empirical proofs of Bell's inequalities and
we argue that none is loophole-free. Then we propose a restricted QM that does not contain measurement postulates and that
does not claim that all state vectors (self-adjoint operators) are states (observables). The contradiction of such restricted
QM with Bell's inequality cannot be shown as a theorem, but only by the design of a loophole-free experiment. Finally, we
argue that noise has been underestimated in quantum theory. It does not appear in QM, but it is essential in quantum field
theory. We conjecture that noise will prevent the violation of Bell's inequality. 相似文献
137.
ORTHOGONAL MATRIX POLYNOMIALS WITH RESPECT TO A CONJUGATE BILINEAR MATRIX MOMENT FUNCTIONAL: BASIC THEORY 总被引:1,自引:1,他引:0
In this paper basic results for a theory of orthogonal matrix polynomials with respect to a conjugate bilinear matrix moment functional are proposed. Properties of orthogonal matrix polynomial sequences including a three term matrix relationship are given. Positive definite conjugate bilinear matrix moment functionals are introduced and a characterization of positive definiteness in terms of a block Haenkel moment matrix is established. For each positive definite conjugate bilinear matrix moment functional an associated matrix inner product is defined. 相似文献
138.
139.
Antonio Salmerón-García Emilio Lopez-Lopez Eva Román José Cabeza Natalia Navas Luís Fermín Capitán-Vallvey 《Chromatographia》2008,67(9-10):767-772
A novel LC method was applied to enhance the peak resolution of two ecdysteroids: 20-hydroxyecdysone and its 3-epimer. An isocratic solvent system of methanol–water (6:4, v/v) was used on a C18 column, and 100 μL of water was injected during the development in such a manner that the eluted solvent peak appeared exactly between the two overlapping peaks. This resulted in the increased retardation of the later-eluted peak, and in a good separation of the two compounds within 4.5 min. 相似文献
140.
E. Elizalde 《Foundations of Physics Letters》1993,6(3):283-288
The postulates which have been introduced recently in order to obtain a quantum Hamilton-Jacobi formalism, starting from the classical one, are revised. It is shown that some of them can be replaced by alternative assumptions which happen to be much more natural. The quantum Hamilton-Jacobi equation is obtained as an eigenvalue equation on the quantum wave amplitude. 相似文献