Excess enthalpies of binary mixtures of <Emphasis Type="Italic">ortho</Emphasis>-, <Emphasis Type="Italic">meta</Emphasis>-, and <Emphasis Type="Italic">para</Emphasis>-structural isomers

The excess molar enthalpies of 8 binary mixtures for the o-, m-, and p-isomers of fluoroiodobenzene, fluoromethoxybenzene, bromofluorobenzene, chlorofluoro-benzene, difluorobenzene, fluoromethylbenzene, fluoronitrobenzene, and aminofluoro-benzene were measured at 298.15 K. The changes of the measured enthalpies were very small. The experimental results revealed that the isomers containing two electron-acceptor groups showed the most positive excess enthalpy change, while isomers containing both one electron donor and one electron acceptor group, such as aminofluorobenzene, showed more stable and always the most negative results.     

Velocity dispersion and attenuation in granular marine sediments: comparison of measurements with predictions using acoustic models

The large velocity dispersion recently reported could be explained by a gap stiffness model incorporated into the Biot model (the BIMGS model) proposed by the author. However, at high frequencies, some measured results have been reported for negative velocity dispersion and attenuation proportional to the first to fourth power of frequency. In this study, first, it is shown that the results of velocity dispersion and attenuation calculated using the BIMGS model are consistent with the results measured in two kinds of water-saturated sands with different grain sizes, except in the high-frequency range. Then, the velocity dispersion and attenuation in six kinds of water-saturated glass beads and four kinds of water-saturated silica sands with different grain sizes are measured in the frequency ranges of 80-140 and 300-700 kHz. The measured results are compared with those calculated using the BIMGS model plus some acoustic models. It is shown that the velocity dispersion and attenuation are well predicted by using the BIMGS model in the range of kd ≤ 0.5 (k: wavenumber in water, d: grain diameter) and by using the BIMGS model plus multiple scattering effects in the range of kd ≥ 0.5 in which negative velocity dispersion appears.     

Analysis of A-DLTS spectra of MOS structures with thin NAOS SiO2 layers

A set of MOS structures with thin SiO₂ layers prepared by nitric acid oxidation (NAOS) method was investigated using acoustic deep level transient spectroscopy (A-DLTS) to explain the role of annealing treatment (post-oxidation annealing (POA) and post-metallization annealing (PMA)) at different conditions on the distribution of interface states. The activation energies of interface states and the corresponding capture cross-section were calculated both from Arrhenius plots constructed for individual peaks of the A-DLTS spectra and applying the method of modeling of measured acoustic spectra. The energy distribution of the interface states was determined also from the dependence of acoustoelectric response signal (ARS) on the external bias voltage (U _ac - V _G curves). By comparing the A-DLTS spectra, U _ac - V _G characteristics and some electrical measurements (G-V, I-V curves) of investigated MOS structures with no treatment with those treated with POA and/or PMA, the role of individual treatments was observed. The definite decrease of the interface states in the structures with the PMA treatment in comparison with the POA treatment was confirmed too.     

On the computation of all eigenvalues for the eigenvalue complementarity problem

In this paper, a parametric algorithm is introduced for computing all eigenvalues for two Eigenvalue Complementarity Problems discussed in the literature. The algorithm searches a finite number of nested intervals \([\bar{l}, \bar{u}]\) in such a way that, in each iteration, either an eigenvalue is computed in \([\bar{l}, \bar{u}]\) or a certificate of nonexistence of an eigenvalue in \([\bar{l}, \bar{u}]\) is provided. A hybrid method that combines an enumerative method [1] and a semi-smooth algorithm [2] is discussed for dealing with the Eigenvalue Complementarity Problem over an interval \([\bar{l}, \bar{u}]\) . Computational experience is presented to illustrate the efficacy and efficiency of the proposed techniques.     

Projector Monte Carlo method based on Slater determinants: a new sampling method for singlet state calculations

A new sampling method is proposed for projector Monte Carlo (PMC) calculations based on Slater determinants (SD) in singlet states. Using the symmetry of the ?? and ?? electron determinants, the number of configurations to be considered can be about one-half of the original sampling. We applied the new sampling to the PMC-SD calculations of the H₂O molecule in the ground state. The results were always improved by the new sampling method both for the equilibrium and for bond-stretched structures.     

On a Stationary Problem of the Stokes Equation in an Infinite Layer in Sobolev and Besov Spaces

This paper is concerned with the stationary problem of the Stokes equation in an infinite layer and provides a condition on the external force sufficient for the existence of the solution. Since the Poiseuille flow is a solution to the homogeneous equation, the solution is not unique when p = ∞. It is also proved that, under some suitable conditions, solutions to the homogeneous equation are limited only to the Poiseuille flow.     

Restricted generalized Nash equilibria and controlled penalty algorithm

The generalized Nash equilibrium problem (GNEP) is a generalization of the standard Nash equilibrium problem, in which each player’s strategy set may depend on the rival players’ strategies. The GNEP has recently drawn much attention because of its capability of modeling a number of interesting conflict situations in, for example, an electricity market and an international pollution control. However, a GNEP usually has multiple or even infinitely many solutions, and it is not a trivial matter to choose a meaningful solution from those equilibria. The purpose of this paper is two-fold. First we present an incremental penalty method for the broad class of GNEPs and show that it can find a GNE under suitable conditions. Next, we formally define the restricted GNE for the GNEPs with shared constraints and propose a controlled penalty method, which includes the incremental penalty method as a subprocedure, to compute a restricted GNE. Numerical examples are provided to illustrate the proposed approach.     

Oxygen‐sensing properties of 5,10,15,20‐tetraphenylporphinato platinum(II) and palladium(II) covalently bound on poly(isobutyl‐co‐2,2,2‐trifluoroethyl methacrylate)

A novel methacrylate monomer bearing 5,10,15,20‐tetraphenylporphyrinato palladium(II) (PdTPP) (monomer 1a ) was synthesized and copolymerized with isobutyl methacrylate (IBM) and 2,2,2‐trifluoroethyl methacrylate (TFEM) to give poly (IBM‐co‐TFEM) bearing PdTPP (copolymer 2a ) as a dye‐conjugated oxygen‐permeable polymer for pressure‐sensitive paint applications. The introduction of PdTPP into copolymer 2a was confirmed by UV–vis spectroscopy and extended X‐ray absorption fine structure analysis. The Stern–Volmer plots of the copolymer 2a and a mixture of PdTPP and poly(IBM‐co‐TFEM) both showed downward curvature, unlike that of the platinum complex analogue (copolymer 2b ) previously reported. The plots were successfully fitted with a two‐site model to give two distinct Stern–Volmer constants (K_SV1 and K_SV2) and the partition ratio f₁. Interestingly, the f₁ values for the copolymer 2a were almost constant at about 0.98, whereas those of the mixture of PdTPP and poly(IBM‐co‐TFEM) increased from 0.889 to 0.967 as the temperature was increased. This finding suggests that there are two distinct microheterogeneities, one temperature‐dependent and the other temperature‐independent, in the mixture of PdTPP and poly(IBM‐co‐TFEM). The dye‐conjugation approach effectively eliminates the temperature‐dependent, but not the temperature‐independent microheterogeneity. The luminescence decays of copolymers 2a and 2b and the corresponding mixtures in the absence of oxygen indicated that the temperature‐dependent microheterogeneity involves an oxygen diffusion process, whereas the temperature‐independent one appears to be inherent nature in PdTPP. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 663–670, 2010     

A characteristic ribbon-like supramolecular structure and intermolecular D–A interactions in the crystals of triptycenequinones, triptycene-TCNQs and their clathrates as studied by X-ray investigations

A common ribbon-like structure was found in the crystals of triptycenequinones (TPQs), triptycene-TCNQs (TP-TCNQs) and their clathrates. The characteristic structure can be regarded as a supramolecular unit the formation of which is aided by weak intermolecular D–A interactions. This view is supported by the host–guest D–A interactions appeared in the crystals of the clathrates of 5,8-dimethyl-TPQ and 5,8-dimethoxy-TP-TCNQ. Intermolecular C–HO hydrogen bonds seem to be present in TPQ derivatives.