A simple and general method for the synthesis of multicomponent Na2V6O16.3H2O single-crystal nanobelts

Multicomponent Na2V6O16.3H2O (barnesite) single-crystalline nanobelts were synthesized by a direct reaction-crystallization growth of bulk V2O5 and NaF powders under hydrothermal treatment without using any templates or catalysts. This new strategy could be extended to prepare other one-dimensional multicomponent nanomaterials including ammonium, alkali-metal or alkali-earth metal vanadium oxide bronzes and other transition metal oxyfluorides. This is an efficient and mild solution method with clear advantages over the traditional high-temperature approach for the large-scale production of 1D multicomponent nanomaterials. The applicability of this approach toward the preparation of other inorganic systems, such as tungstates and molybdates, will be explored.     

Gas chromatographic determination of estrone,estradiol and estriol in non-pregnancy plasma

Summary A gas Chromatographic method for the determination of estrone, estradiol and estriol in plasma of normal females is described. Purification is done by means of TLC of the free compounds and the acetates and quantitation is achieved by electron capture-gas chromatography of the estrogen heptafluorobutyrates. Experiments on the validation of the method are described along with some examples of its application.

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Zusammenfassung Eine gaschromatographische Methode zur Bestimmung von Östron, Östradiol und Östriol im normalen weiblichen Plasma wurde beschrieben. Die Reinigung erfolgte durch Dünnschichtchromatographie der freien Verbindungen und ihrer Acetate. Die quantitative Bestimmung wurde gaschromatographisch mit Hilfe eines Elektroneneinfangdetektors an Hand der Östrogenheptafluorobutyrate bewerkstelligt. Versuche zur Bewertung dieser Methode sowie Beispiele für ihre Anwendung wurden beschrieben.

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Supported by USPHS Grants AM 09908 and RCDA 5 K 3-AM-31, 321 (S. K.) and a grant from the Ford Foundation.     

Polyarylate–polystyrene block copolymer from macro-azoinitiator: Synthesis and its thermal properties

A macro-azoinitiator containing polyarylate segment and azo group was prepared by the solution polycondensation of azobiscyanopentanoyl chloride and hydroxy-terminated polyarylates having viscosity-average molecular weights of 6200, 8100, and 12 400. These macro-azoinitiators were used in the radical polymerization of styrene to synthesize polyarylate-polystyrene block copolymers. Thermal properties measured by the differential scanning calorimetry indicated the phase separated morphology of the block copolymers except at low molecular weight of the block constituents. © 1993 John Wiley & Sons, Inc.     

Submanifolds of complex space forms admitting an almost contact metric compound structure

Summary Real hypersurfaces of an almost Hermitian manifold naturally admit an almost contact metric structure and the (f, g, u, v, w, , , )-structure is defined on submanifolds of codimension 3 of an almost Hermitian manifold. We study the so-called semi-invariant submanifolds of a complex space form with almost contact metric compound structure which is a general notion of (f, g, u, v, w, , , )-structure.Dedicated to professor Eulyong Pak on his 60th birthdayThis research was partially supported by Korean Science and Engineering Foundation Grant.