Reinterpretation of the molecular O2 chemisorbate in the initial oxidation of the si(111)7 x 7 surface

The initial oxygen adsorption on the Si(111)7 x 7 surface was investigated by high-resolution x-ray absorption spectroscopy. Below 220 K, a molecular adsorption species is identified by distinctive absorption resonances due to the 1 pi(g) molecular orbitals. The molecular species is metastabilized to have a lifetime of 15-35 min at 135 K only with the presence of atomic adsorbates of more than 0. 1 ML (monolayer). It is thus clearly evidenced that the very initial adsorption is dissociative even at 100 K and the molecular species is not a precursor state. The molecular adsorption structures with the coadsorbed oxygen atoms are suggested.     

Empirical characteristic function approach to goodness-of-fit tests for the Cauchy distribution with parameters estimated by MLE or EISE

We consider goodness-of-fit tests of the Cauchy distribution based on weighted integrals of the squared distance between the empirical characteristic function of the standardized data and the characteristic function of the standard Cauchy distribution. For standardization of data Gürtler and Henze (2000,Annals of the Institute of Statistical Mathematics,52, 267–286) used the median and the interquartile range. In this paper we use the maximum likelihood estimator (MLE) and an equivariant integrated squared error estimator (EISE), which minimizes the weighted integral. We derive an explicit form of the asymptotic covariance function of the characteristic function process with parameters estimated by the MLE or the EISE. The eigenvalues of the covariance function are numerically evaluated and the asymptotic distributions of the test statistics are obtained by the residue theorem. A simulation study shows that the proposed tests compare well to tests proposed by Gürtler and Henze and more traditional tests based on the empirical distribution function.     

Insulinomimetic Zn(II) complexes as evaluated by both glucose-uptake activity and inhibition of free fatty acids release in isolated rat adipocytes

We prepared 4 new Zn(II) complexes with Zn(O4), Zn(N(2)O(2)), and Zn(S2O2) coordination modes and evaluated their insulinomimetic activities in an in vitro study. The insulinomimetic activities of bis(pyrrole-2-carboxylato)zinc (Zn(pc)2), bis(alpha-furonic acidato)zinc (Zn(fa)2), bis(thiophene-2-carboxylato)zinc (Zn(tc)2), and bis(thiophene-2-acetato)zinc (Zn(ta)2) complexes were found to be higher than that of zinc sulfate (ZnSO4). Zn(ta)2 showed the highest insulinomimetic activity among the Zn(II) complexes because of its high lipophilicity.     

Permeability control in electro‐sensitive microcapsules with immobilized ferroelectric liquid crystalline segments

Nylon‐polystyrene microcapsules with immobilized ferroelectric liquid crystalline segments were prepared, and permeability control of an encapsulated core material was investigated under an external electric field. A ferroelectric liquid crystal monomer possessing both mesogenicity and chirality responded effectively to the external electrical field. Permeation of the material (oxprenolol) contained in the inner aqueous core of the microcapsules was enhanced under a weak electric field (2 V). Furthermore, the permeability of oxprenolol did not depend on the external electric field in the absence of the ferroelectric liquid crystal segments. To clarify the controlled‐release mechanism of the core material, the light transmittance of the polymer membranes was quantitatively evaluated under an external electric field using a handmade polarized light transmittance apparatus. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 1749–1757, 2008     

Theoretical studies on magnetic interactions between Cu(II) ions in hydroxypyridone nucleobases

The origin of a ferromagnetic interaction between Cu²⁺ ions in the Cu²⁺–DNA system which reported by Tanaka et al. is examined by using DFT calculations. In order to consider effects of an entanglement and a dis-entanglement of the double helix chain, three types of structural disorders i.e. distance, rotation angle and discrepancy in XY-plane, are considered in the model dimer structure. All calculated results show that J_ab values are weak anti-ferromagnetic couplings. Boltzmann distribution simulation indicates that the high spin (HS) species exist 21% at 1.5 K by thermal excitation within the model structure.     

Colorimetrie, Photometrie

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