Improved flexibility in MODR using a supersonic jet source: Applications to CO+ and CN

Microwave—optical double resonance (MODR) is carried out on the N = 1 ← 0 transitions of CN and CO⁺, which are rotationally cooled in a supersonic jet. Large modulations in the probe LIF (≈100%) are observed without optical saturation, demonstrating that short pulse dye lasers may be used in MODR. Hyperfine constants for ¹²C¹⁴N in X?²Σ^?(ν = 2) are reported.     

Refractive index profiles of LiNbO3: Ti waveguides

Eight LiNbO₃: Ti waveguides have been fabricated under differing conditions. The effective refractive indices of guided modes have been measured and successfully fitted to Gaussian index profiles. The change of refractive index and titanium concentration are related by a power law, the exponents being different for the extraordinary and the ordinary beam.     

Zum Archimedischen Axiom

Ohne Zusammenfassung

---

Dem Wirken des hervorragenden ungarischen GeometersWolfgang Bolyai zum 200. Geburtstag     

Kombinierter Nachweis von 14C-markierten Eiwei?stoffen und Aminos?uren nach S?ulen-Chromatographie an Sephadex

Zusammenfassung Es wird eine säulen-chromatographische Methode beschrieben, die mit kontinuierlich arbeitenden, registrierenden Meßgeräten gleichzeitig die UV-Absorption, die Radioaktivität und pH-Kurve von Aminosäuren, Peptiden und Proteinen zu erfassen gestattet. Nach Sammeln des Eluats in Fraktionen kann außerdem die Ninhydrinanfärbbarkeit der freie Aminogruppen enthaltenden Verbindungen gemessen werden. Hiermit ist auf einfache Weise die Möglichkeit gegeben, den Einbau von Prolin in Weizeneiweiß im Verlaufe der Reifung zu verfolgen.

---

Combined detection of ¹⁴C-labelled proteins and amino acids after column chromatography on sephadex. II

With chromatography on gel columns a method has been developed which makes it possible to registrate continuously and simultaneously the UV-absorption, the radioactivity and the pH-curve of amino acids, peptides and proteins with an analyzing system. After the eluat has been collected in fractions the ninhydrin reaction can be carried out. In this way the incorporation of proline in wheat protein is measurable during ripening period in a simple way.

---

---

Nr. 3209 der Veröffentlichungen der Bundesforschungsanstalt für Getreideverarbeitung.     

Die Sprungtemperatur von Supraleitern

An iteration procedure allows to find an equation for the critical temperatureT _c of superconductors starting from the linearized Eliashberg equations without using any cutoff parameters or a Coulomb pseudopotential. Explicit calculation ofT _c for a simple model leads to Morel, Anderson and McMillan's^1,2 expression thereby allowing for a physical interpretation of the commonly used approximation for the Coulombpseudopotential.     

Ultrafast dynamics of delocalized and localized electrons in carbon nanotubes

We report on the dynamics of the dielectric function of single-wall carbon nanotubes in the 10-30 THz frequency range after ultrafast laser excitation. The absence of a distinct free-carrier response is attributed to the photogeneration of strongly bound excitons in the tubes with large energy gaps. We find a feature of enhanced transmission caused by the blocking of optical transitions in small-gap tubes. The rapid decay of a featureless background with pronounced dichroism is associated with the increased absorption of spatially localized charge carriers before thermalization is completed.     

Large amplitude oscillations (switching) of bi-stable vortex structures in zero field

A ferromagnetic block (2a×2b×2c) with three unequal axes supports a vortex structure that intersects each of the two opposite surfaces of largest area. Swirls appear at points (xp, yp, c) and (?xp, yp, ?c) in state-A. In state-B the swirls are at points (?xp, ?yp, c) and (xp, ?yp, ?c). With micromagnetic simulations we demonstrate the possibility of a nucleation-free switching between those states, with possible applicability in devices. The oscillations are accompanied by large external fields from the magnetic charge at the core of the intersections of the vortices with the surface. These fields of the order of a quarter of the saturation inductance move over a distance 2xp～c in fractions of a ns.