La-doped lead magnesium niobate (Pb1-xLax[Mg(1+x)/3Nb(2-x)/3]O3, PLMN, x=0.1, 0.2) was prepared by a polyethylene glycol-based process (PEG method) as follows: PEG-cation (La3+, Mg2+, Nb5+) complex was oxidized and the obtained oxide was mixed with PbO. This oxide mixture was fired to obtain PLMN. This PEG method enabled to prepare the single phase of perovskite structure of PLN at 1023K. This temperature is lower than that used in the solid state reaction method. The PLMN prepared by the PEG method had quite little compositional fluctuation and structural strain. PLMN has an ordering domain with the super lattice structure of B site cations in the perovskite structure. The crystallite size of the ordering domain in the PLMN obtained by the PEG method increased when the molecular weight of the initial PEG increased (from 150 to 7500). The formation process of the ordering domain was under the influence of the cation distribution in the PEG-cation complex.
Clinical studies on the endocrine function of the pancreas in diabetes mellitus were performed before and after treatment. Mean serum insulin activity expressed as glucose uptake of the diaphragm was 0.97 mg. per unit weight of the diaphragm in type I diabetics before treatment, while in type II it was -0.33. Type I diabetics did not show an increase in serum insulin activity after the dietary treatment, however type II did show an increase. A significant correlation between serum insulin activity and fasting blood sugar was observed before treatment. Serum insulin activity after the administration of glucose increases in seven out of twelve cases of type I diabetics and five out of ten cases of type II diabetics. The increase in serum insulin activity, however, was not observed in five out of twelve cases of type I diabetics and five out of ten cases of type II. The mean levels of plasma glucagon-like activity before treatment were 5.5, 46.8 and 54.0μg. per dl. in normal subjects, type I diabetics and type II diabetics, respectively. Glucagon-like activity decreased after treatment in both types of diabetics. In several diabetics, whose diabetic state was not improved, it did not decrease. There was observed a significant correlation between glucagon-like activity in plasma and fasting blood sugar. The mean ratios of α to β cells in islets of the pancreas were 1:5.59, 1:5.04 and 1:4.03 for non-diabetics, type I diabetics and type II diabetics, respectively.
A surface-modified α-FeOOH (denoted α-FeOOH[S]) was prepared by adsorption of stearate ion onto an α-FeOOH powder. The non-surface-modified α-FeOOH (denoted simply α-FeOOH) and α-FeOOH[S] powders contained particles of almost identical shape and size. When ferrite NiFe2O4 compacts were prepared by sintering the mixed powders of the surface-modified α-FeOOH[S] and NiO at 1573 K for 1 h, the total porosity of the NiFe2O4 compacts was 14.8% less than that found for compacts prepared by sintering the mixed powders of the non-surface-modified α-FeOOH and NiO. Although the morphology of the α-FeOOH and the α-FeOOH[S] was the same, the use of the α-FeOOH[S] powder accelerated densification of the NiFe2O4 compacts. The mixed powder containing α-FeOOH[S] and MO (M = Co, Zn) also formed denser ferrite compacts than when the powder containing the non-surface-modified α-FeOOH was used. The α-Fe2O3 and α-Fe2O3[S] powders were prepared by firing the non-surface-modified α-FeOOH and the α-FeOOH[S] powders, respectively, at 873 K for 1 h. The XPS O 1s and Fe 2p spectra of the α-Fe2O3 and α-Fe2O3[S] indicated that the surface of the α-Fe2O3[S] powder had a greater Fe3O4-like phase with oxygen vacancy than that of the α-Fe2O3 powder. The temperature dependence of the electrical conductivity of the α-Fe2O3 and α-Fe2O3[S] powder compacts also indicated the presence of an Fe3O4-like phase with a mixed-valence state of Fe3+ and Fe2+ on the surface. This Fe3O4-like phase plays an important role in the sintering and densification of ferrite compacts.
A study was undertaken concerning the kinetics and mechanism of the phosphidation of silver at 450°C in phosphorus vapor at 44.0 to 80.0 kPa. X‐ray diffraction patterns and an electron probe microanalysis of the reaction products demonstrated that the films were composed of single layers of . A marker experiment indicated that silver was apparently the component that diffused across these films. In the early stage, the phosphidation obeyed a linear rate law and its rate‐determining process was regarded as the surface reaction; that is, the chemisorption of molecules generated by dissociation of a molecule. When the thickness of a phosphide layer reached a critical value, the reaction kinetics exhibited a gradual transition from the linear to the parabolic rate law as a result of the rate‐determining process changing from adsorption to solid‐state diffusion.
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSynthesis and Structure of Dialuminiohexaeuropiopentakis(hexaniobate): a High-Nuclearity Oxoniobate ComplexTomoji Ozeki, Toshihiro Yamase, Haruo Naruke, and Yoshinori SasakiCite this: Inorg. Chem. 1994, 33, 3, 409–410Publication Date (Print):February 1, 1994Publication History Published online1 May 2002Published inissue 1 February 1994https://pubs.acs.org/doi/10.1021/ic00081a004https://doi.org/10.1021/ic00081a004research-articleACS PublicationsRequest reuse permissionsArticle Views388Altmetric-Citations79LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-AlertscloseSupporting Info (1)»Supporting Information Supporting Information Get e-Alerts
