Schnelle Trennung von Rückstoßprodukten in der Gasphase

Experiments are described in which recoil products are separated fast and selectively. The aim of these investigations is an identification of short-lived nuclides, either for the study of nuclear reactions or for the study of decay properties of new products. The recoil products were provided by a Cf-252 source. The transportation zone and the identification zone could be heated to different temperatures. Using N₂ as carrier gas it was possible to separate Te selectively under certain experimental conditions. When Cl₂ was added, Sb, Tc, Nb, Mo, Zr, Ru and Sn were transported. Transport output was determined in dependence of temperature and composition of the gas.     

Zur Verbindungsbildung von MeO: M2O3. IV. Zur Struktur von monoklinem SrAl2O4

Einkristalle von SrAl₂O₄ wurden durch Hochtemperaturreaktionen von SrO mit Al₂O₃ dargestellt und röntgenographisch untersucht (a = 844,7; b = 881,6; c = 516,3 pm;β = 93,4₂°; Raumgruppe C–;P2₁, Z = 4). Die Tetraederabfolge in den Sechsringen dieser aufgefüllten Tridymit-Struktur wird mit der ähnlicher Oxometallate verglichen. Compound Formation MeO:M₂O₃. IV. Structure of Monoclinic SrAl₂O₄ Single crystals of SrAl₂O₄ were prepared by high temperature CO₂-LASER technique and investigated by X-ray methods. (a = 844.7; b = 881.6; c = 516.3 pm; β = 93.4₂°; space group C–P2₁, Z = 4). The orientation of the tetrahedra in this stuffed tridymite structure is discussed in comparison with related oxometallates.     

Self-Assembly of Gold Nanoclusters on Molecularly Modified GaAs

The elaboration of closed-packed monolayers of Au₅₅(PPh₃)₁₂Cl₆ clusters on oxidized and non-oxidized GaAs surfaces is reported. The first part of this work describes the use of silanethiol modified GaAs oxide surfaces to trap 18 nm gold colloids and Au₅₅(PPh₃)₁₂Cl₆ clusters. The surfaces characterized by AFM measurements present high-quality coverage on a quite long range for both metallic species. The second part is devoted to the elaboration of Au₅₅(PPh₃)₁₂Cl₆ cluster monolayers on non-oxidized p-type GaAs substrates, functionalized with dithiol molecules. AFM measurements demonstrate the presence of closed-packed two-dimensional arrangements of Au₅₅ clusters.     

Koordinationsverbindungen von Aminoacridin-N-oxiden mit Metallthiocyanaten der 3d-Reihe

Coordination Compounds of Aminoacridine-N-oxides with Thiocyanates of the 3d Metals . Reactions of thiocyanates of the 3d metals with selected aminoacridine-N-oxides in homogeneous dilutions of N,N-dimethylformamide form compounds of the type [M(AAcNO)_a(DMF)_b(NCS)₂] · cDMF and [M′(AAcNO)_d(DMF)_e(NCS)₃] · fDMF, M = Mn²⁺, Co²⁺, Ni²⁺, Cu²⁺, Zn²⁺; M′ = Cr³⁺, Fe³⁺; AAc^INO = 3,6-diamino-2,7-dimethylacridin-N-oxide, AAc^IINO = 3,6-bis(dimethylamino)acridin-N-oxide, AAc^IIINO = 2-ethoxy-6,9-diaminoacridin-N-oxide; a = 1, 2, 3, 4; b = 0, 1; c = 0, 1, 2, 3; d = 1, 2, 3; e = 0, 1, 2; f = 0, 1, 2, 3. The complexes are characterized by IR (4000–200 cm^?1) and UV-VIS spectra in solutions and solids and by EPR and conductivity investigations.     

Low temperature absorption spectra of TcO 4 − and ReO 4 − in KClO4

The low temperature spectra of TcO ₄ ^– and ReO ₄ ^– both show two band systems with pronounced vibrational structures. The bands are identified as¹ A ₁¹ T ₂ transitions. No other bands are observed with certainty. It seems likely that the KClO₄ crystals contain KReO₄ crystallites. They are therefore not pure mixed crystals. It is concluded that the virtual orbital (2e) used in the construction of the low lying states resembles an atomic nd orbital more and more when going from n=3, Mn to n=5, Re.

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Zusammenfassung Die Tieftemperaturspektren von TcO ₄ ^– und ReO ₄ ^– zeigen beide zwei Bandensysteme mit ausgeprägten Schwingungsstrukturen. Die Banden werden als ¹ A ₁¹ T ₂-Übergänge identifiziert. Keine anderen Banden werden mit Sicherheit beobachtet. Es scheint wahrscheinlich, daß die KClO₄-Kristalle KReO₄-Kristallite enthalten und deswegen keine reinen Mischkristalle sind. Es wird geschlossen, daß das virtuelle Orbital (2e), welches zur Konstruktion der tiefliegenden Zustände gebraucht wird, in der Reihe n=3, Mn bis n=5, Re immer weitgehender einem nd-Atomorbital ähnelt.

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Nachwuchsstipendiat, Schweizerischer Nationalfonds.     

Chloridionenübergänge in Phenylphosphoroxychlorid, 1. Mitt.: Spektrophotometrische Untersuchungen an Eisen (III)-chlorid-Lösungen

Zusammenfassung FeCl₃ liegt in PhPOCl₂ als roter solvatisierter Komplex, in Gegenwart von polaren Chloriden als gelbes [FeCl₄]^–-Ion vor. BCl₃, SnCl₄, TiCl₄, PCl₅ und wahrscheinlich auch HgCl₂ und SbCl₃ geben an FeCl₃ je 1 Chloridion ab, ZnCl₂ gibt beide Chloridionen und AlCl₃ zwei Chloridionen fast vollständig und ein drittes in geringem Umfang ab. Die Donorstärke nimmt in der Reihe KClEt₄NCl>1/2 AlCl₃>-TiCl₄>PCl₅>1/2 ZnCl₂>BCl₃ SnCl₄[AlCl]⁺⁺>HgCl₂>SbCl₃ ab. Als Chloridionenakzeptor ist nur SbCl₅ dem FeCl₃ ebenbürtig, die oben genannten Chloride sind wesentlich schwächere Akzeptoren.Mit 4 AbbildungenHerrn Professor Dr.L. F. Audrieth zum 60. Geburtstag gewidmet.     

Application of high-performance liquid chromatography of some antibiotics in clinical microbiology

During recent years high-performance liquid chromatography has become an excellent tool for the determination of antibiotics in biological fluids. Compared with biological assays, the major benefits of this method are specificity and rapidity. In particular, the determination of biologically inactive metabolites emphasizes that this technique plays an outstanding role for the analysis of antibiotics. This paper describes how the method can be used in the analysis of several antibiotics and demonstrates the efficacy of this method for clinical microbiology. Methods for the determination in biological fluids of acylaminopenicillins (azlocillin, mezlocillin, piperacillin and aspoxicillin), quinolones (ciprofloxacine, norfloxacine and ofloxacine), a penem (imipenem) and a cephalosporin (cefixime) are summarized. Furthermore, their application to in vitro studies and their trial in clinical studies are described.     

Buchbesprechungen

Ohne Zusammenfassung     

Category equivalences of clones

This note was inspired by McKenzie's recent paper [8] whose main result is a characterization of categorical equivalence (for short category equivalence) between varieties. Here we use this result to define category equivalent clones and to describe all clones category equivalent to maximal clones. If one is interested in maximal clones only up to category equivalence it is sufficient to consider very simple maximal clones, essentially the same as considered in Jablonski's early papers about maximal clones [6]. The results we have found encourage us in our feeling that category equivalence could be a useful tool in clone theory.Dedicated to the memory of Alan Day.Presented by J. Sichler.