Synthesen von heterocyclen, 143. Mitt.: Eine Synthese von Oxazolo[3,2-a]chinolinen

Zusammenfassung Substituierte 3,4-Dihydrocarbostyrile reagieren mit Oxalylchlorid zu den entsprechenden Oxazolo[3,2-a]chinolinen, während mit monosubstit. Malonylchloriden N-Acylierung stattfindet.

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Syntheses of heterocycles CXLIII: A synthesis of oxazolo-[3.2-a]quinolines

Substituted 3.4-dihydro-carbostyriles react with oxalyl chloride to give the corresponding oxazolo[3.2-a]quinolines1–3, while monosubstituted malonyl chlorides yield N-acylated carbostyrils.

     

Evaluation of new single crystal piezoelectric materials for surface acoustic-wave applications

Surface acoustic waves (SAW), or Rayleigh waves, bound to the surfaces of piezoelectric materials are becoming rapidly significant in electronic device applications, particularly as VHF-UHF frequency filters and versatile time-domain processors. The majority of available devices utilize either signle crystalline quartz or lithium niobate as the piezoelectric medium. This paper describes briefly the growth and critical evaluation of SAW impedance and propagation properties for certain new single crystal piezoelectric materials. Crystals discussed are Czochralski-grown bismuth germanium oxide, films of zinc oxide and aluminum nitride both epitaxially grown on single crystal sapphire, and flux-grown beryllium oxide. It is concluded that bismuth germanium oxide may prove an important cost-effective alternative to both quartz and lithium niobate, and that either zinc oxide or aluminum nitride is destined to prove invaluable in the realization of monolithic circuits such as programmable tapped delay lines, in which SAW will be interfaced with metal-oxide semiconductor (large scale integrated) technology, and active SAW elements employing functional integration.     

Zum radiogenen Argon in Eisenmeteoriten

Ohne Zusammenfassung     

Generalized mean-square amplitudes of vibration in some XY4 type ions (II)

The generalized mean-square amplitudes of vibration and mean amplitudes of vibration have been computed for CrO^3-₄, Mn¹⁸O^-₄, MoSe^2-₄ and WSe^2-₄ ions at three temperatures, T = 0°K, T = 298°K, T = 500°K, employing Cyvin's method. The results have been discussed in the light of atomic weight and electronegativity of the atom in the ionic system.     

Tüpfelmethode auf Phosphat,angewandt in prähistorischer Forschung (als Feldmethode)

Zusammenfassung Die Tüpfelmethode nachFeigl auf Phosphat wurde durch die Einführung von Ascorbinsäure als Reduktionsmittel als Feldmethode modifiziert. Sie eignet sich entsprechend ihrer leichten und raschen Ausführbarkeit und Empfindlichkeit zur Untersuchung von Bohrprofilen auf die in prähistorischen Siedlungsschichten erhöhten Phosphatgehalte.

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Summary The spot test for phosphate developed byFeigl was modified by the use of ascorbic acid as the reducing agent; a field method results. In accord with the ease of conducting this test and its rapidity, and sensitivity, it has proved useful for the study of boring profiles with respect to their enhanced phosphate contents in prehistoric settlement strata.

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Résumé On a modifié la méthode à la touche deFeigl pour les phosphates sur le terrain, en employant l'acide ascorbique comme agent de réduction. En raison de son exécution facile et rapide et de sa sensibilité, elle convient à l'étude des profils de carottage pour les teneurs en phosphates élevées dans les couches de dépôts préhistoriques.

     

Beiträge zur Chromatographie organischer Substanzen. VI. Die Dünnschichtchromatographie der Kohlehydrate

Zusammenfassung Es wird über die Trennung einiger Mono-, Di- und Trisaccharide auf Kieselgur- und Kieselgelträgern berichtet. Ferner wird die Trennung Raffinose-Saccharose bei ungünstigen Mengenverhältnissen (z.B. Melasse) durchgeführt und hierzu eine verbesserte Keilstreifentechnik entwickelt.

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Summary A report is given on the separation of several mono-, di-, and trisaccharides on kieselguhr and silica gel carriers. In addition, the raffinose-saccharose separation was carried out with unfavorable quantity ratios (for example molasses) and an improved wedge strip technique was developed.

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Résumé On décrit la séparation de quelques mono-, di- et trisaccharides sur supports de kieselguhr et de gel de silice. On réalise ensuite la séparation raffinosesaccharose en proportions quelconques (par exemple mélasse) et l'on propose à partir de cela une technique de la bandelette en forme de coin améliorée.

     

Scanning Kelvin Microscope: a new method for surface investigations

Based on the well known Kelvin probe for work function measurements a new microstructure analysis system - the Scanning Kelvin Microscope - has been developed. It allows to measure simultaneously with high lateral resolution the distribution of the contact potential difference (CPD) between a conductive sample and a reference probe together with the topographical structure of the sample surface. The measurement is contact free and non-destructive and can be carried out in natural environments. At present the lateral resolution of the measurement approaches 5 microm. The results can be displayed on a computer in three dimensional colour pictures.     

AFM and XRD investigation of crystalline vapor-deposited C60 films

The morphological and structural properties of C₆₀ films deposited on quartz substrates by sublimation at 320–500° C under high vacuum have been investigated using atomic force microscopy (AFM) and reflection X-ray diffraction (RXRD). The thickness of the films varied between 0.2 m and 10 m. AFM showed that the films consist predominantly of cubic crystals of a few micrometer in size with well-developed (111) and (100) faces. The crystallographic investigation revealed a strongly preferred [111] growth direction which is very sensitive to the deposition rate and substrate temperature. The influence of the experimental parameters on the morphology of the crystals and on the preferred orientation of the films is discussed in view of the AFM and RXRD results.