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Generation of Complex Metal Oxides by Aerosol Processes: Superconducting Ceramic Particles and Films
Toivo T. Kodas 《Angewandte Chemie (International ed. in English)》1989,28(6):794-806
Complex metal oxides, including ferroelectric, ferrimagnetic and superconducting ceramics, have a variety of technologically useful properties that can be exploited for a number of applications. Fabrication of complex metal oxides ceramics with specific properties reqires high-purity powders with controlled chemical compositions, size distributions, and morphologies. Powders with these characteristics can be produced by aerosol processes in which fine particles are generated in gaseous flow systems. The particles can also be deposited from the gas phase onto surfaces to form films. This paper will discuss the use of aerosol processes for the generation of complex metal oxide powders. A review of aerosol processes will be presented first, followed by a discussion of the methods used for the generation of superconducting ceramic powders. Examples include the production of YBa2Cu3O7, La1.85Sr0.15CuO4, and Tl-Ca-Ba-Cu-O powders and films. Emphasis will be placed on defining the conditions required for the generation of chemically homogeneous particles with controlled morphologies. 相似文献
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Toivo Leiger 《manuscripta mathematica》1984,45(3):293-307
Let A and B be normal matrices. In :={x=(xk) ¦ xk} we define the order relation A by xA0:<=>
k=0
n
ankxk0 (n ). Let T be a row-finite matrix. A is called T-section-positive, if ktmkxke(k) A0 (m ) for xA0 (see [5]). We study the relation between T-sectional positivity and T-sectional boundedness. An (A,B)-summability factor sequence =(k) is called positive, if (kxk)B0 for each xcA with xA0. For B-section-positive matrices A we give a functional analytic characterization of positive (A,B)-summability factor sequences.
Die Arbeit entstand während eines vom DAAD unterstützten Forschungsaufenthalts an der Fernuniversität-Gesamthochschule Hagen 相似文献
Die Arbeit entstand während eines vom DAAD unterstützten Forschungsaufenthalts an der Fernuniversität-Gesamthochschule Hagen 相似文献
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Pekka V?h?oja Ilkka V?lim?ki Katri Heino Paavo Per?m?ki Toivo Kuokkanen 《Analytical sciences》2005,21(11):1365-1369
Certain wear metals (Fe, Cr, Ni, Cu and Zn) of various lubrication oils were determined by means of ICP-OES and FAAS. The kerosene dilution method, which is used widely together with ICP-OES, was applied with both methods here. Calibration standards were made from a commercial organo-metallic standard. Our aim was to clarify the possibility of using the quick kerosene dilution method together with FAAS for a rapid check for certain indicator metals. Metal determinations with FAAS were accurate enough for quantitative work in machine condition diagnostics and waste oil characterization, when compared with those with ICP-OES. 相似文献
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Zoltn A. TthOlavi Raatikainen Toivo Naaranlahti Seppo Auriola 《Journal of chromatography. A》1993,630(1-2):423-428
A high-performance liquid chromatographic method was developed for the determination of the non-glycosidic anthraquinones alizarin (1,2-dihydroxy-9,10-anthracenedione), emodin (1,3,8-trihydroxy-6-methyl-9,10-anthracenedione) and anthraquinone (9,10-anthracenedione). The anthraquinones were separated by isocratic elution on a 125 × 4.6 mm I.D. column containing ODS Hypersil 5 reversed-phase material using methanol-5% acetic acid (pH 3.0) (70:30) as the mobile phase. Free alizarin was determined in plant cell suspension cultures of Rubia tinctorum and free emodin in mushrooms (Dermocybe sanguinea). The effective extraction of anthraquinones from plant cells was achieved with 80% (v/v) ethanol after incubation for 10 h at 80°C. Prepurification and concentration of anthraquinones in the plant cell and mushroom extracts were effected by a solid-phase technique using C8 cartridges. 相似文献
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The authors investigated in Boos and Leiger (2008) [5] the ‘duality’ of the Nikodym property (NP) of the set of all null sets of the density defined by any nonnegative matrix and the Hahn property (HP) of the strong null domain of it. In this paper, the investigation of the intimated duality is continued by considering densities defined by sequences of nonnegative matrices. These considerations are motivated by the known result that the ideal of the null sets of the uniform density has NP. In this context the general notion of S-convergence of double sequences (cf. Drewnowski, 2002 [8]) containing Pringsheim convergence, Hardy convergence and uniform convergence of double sequences is used. 相似文献
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Johann Boos Daniel J. Fleming Toivo Leiger 《Journal of Mathematical Analysis and Applications》1996,200(3):519
In this note we consider various types of oscillating properties for a sequence spaceEbeing motivated by an oscillating property introduced by Snyder and by recent papers dealing with theorems of Mazur–Orlicz type and gliding hump properties. Our main tools, two summability theorems, allow us to identify two such oscillating properties for a sequence spaceEone of which provides a sufficient condition forEFto implyEWFwhile the other affords a sufficient condition forEFto implyESF. HereFis anyL-space, a class of spaces which includes the class of separable FK-spaces,SFdenotes the elements ofFhaving sectional convergence, andWFdenotes the elements ofFhaving weak sectional convergence. This, in turn, is applied to yield improvements on some other theorems of Mazur–Orlicz type and to obtain a general consistency theorem. Furthermore, combining the above observations with the work of Bennett and Kalton we obtain the first oscillating property on a sequence spaceEas a sufficient condition forEβ, the β-dual ofE, to be σ(Eβ, E) sequentially complete whereas the second assures both the weak sequential completeness ofEβand the AK-property forEwith the Mackey topology of the dual pair (E, Eβ). 相似文献