Relaxation,postponement, and features of the attractor in a driven varactor oscillator

The driven varactor oscillator is investigated by numerical integration of its ODEs using the standard model of circuit theory. Attention is given to some properties of the basic relaxation mechanism. For time dependent amplitudes of the sinusoidal driving voltage the post-ponement of the bifurcations is characterized by transient Lyapunov numbers. The postponement of the first bifurcation shows the same dependence on the sweep velocity as in the case of the nonautonomous quadratic map. The shapes of the attractors are displayed in extended phase space. Generalized Renyi-dimensionsD ₀ andD ₁ have been determined in the chaotic region. A corresponding twodimensional Pioncaré map indicates selfsimilarity.     

Low-energy πN partial wave analysis

An energy-independent partial-wave analysis has been performed on pion-nucleon elastic and charge-exchange differential cross sections and elastic polarizations, for lab. momenta below 500 MeV/c. The amplitudes were constrained by a simultaneous fixed momentum transfer analysis, which leads to a unique and smooth solution. The masses and widths of Δ⁺⁺ and Δ⁰ have been redetermined from total cross sections as m_Δ⁺⁺ = 1230.9 ± 0.3 MeV, m_Δ⁰ = 1233.6 ± 0.5 MeV, Γ_Δ⁺⁺ = 111 ± 1 MeV and Γ_Δ⁰ = 113 ± 1.5 MeV. For the pion-nucleon coupling constant the value |² = 0.079 ± 0.001 was obtained.     

Four-channel enzyme thermistor system for process monitoring and control in biotechnology

A newly developed four-channel enzyme thermistor system is presented and its application to biotechnological process monitoring is discussed. Different sugars were detected on-line during the cultivation of Cephalosporium acremonium and Bacillus licheniformis on technical media and during a starch hydrolysis process with immobilized thermostable enzymes. Immobilized enzymes and entrapped microorganisms were used as biological compounds in this biosensor.     

Soliton contribution to correlations in a system of coupled chains

A model representing a two- or a three-dimensional array of classical harmonic chains withnonlinear coupling between them is investigated. Physically real systems to which this model applies are discussed. The model exhibits soliton-like nonlinear modes. The influence of these nonlinear modes on the static and the dynamic correlation functions is calculated by generalizing techniques developed for strictly one-dimensional systems. In the static correlation functions these modes lead to minor quantitative changes only. In certain dynamic correlation functions, however, a central peak is found to occur due to the nonlinear modes. The total weight and the width of this peak are calculated for a real spin system.     

Mass spectra of bithiophthalide and related compounds

High resolution mass spectra of biphlhalidu ( 1 ), bithiophthalide ( 2 ), and thioindigo ( 3 ) were investigated and the major fragmentation patterns were elucidated. The simultaneous loss of two sulfur atoms from the molecular ion of 2 was particularly noteworthy.     

Level and age effects in infant frequency discrimination

Frequency difference limens (FDLs) were estimated for 3-, 6-, and 12-month-old infants and for adults using pure tones at 500, 1000, and 4000 Hz. Each listener provided an FDL at 40 dB and at a higher (80 dB, in most cases) sensation level (SL). An observer-based behavioral testing technique was used. The FDLs of 3-month-olds were worse than those of adults at all three frequencies, and increased with increasing frequency. The FDLs of 6- and 12-month-olds were worse than those of adults at 500 and 1000 Hz, but not at 4000 Hz. Decreasing the SL led to an increase in the FDL of about the same magnitude at all ages, and the same age differences were found at both SLs. Thus infant-adult differences in FDL are not a simple consequence of differences in absolute sensitivity. Infant FDLs at one SL were also found to be significantly correlated with the FDL at the other SL. The FDLs at one age were, in general, predictive of the FDL at a later age in a longitudinal sample of infants. Models that might account for these age-related differences are discussed.     

Gemischt-Ligand-Komplexe von Eisen(III) mit Brenzkatechin-3,5- disulfonsäure (Tiron) und Thiocyanat in wäßriger Lösung

Mixed-Ligand complexes of Iron(III) with Pyrocatechol-3,5- disulfonie Acid (Tiron) and Thiocyanate in Aqueous Solution In the system iron(III), tiron, thiocyanate two ternary complexes could be detected in acid solution. By spectrophotometric measurements we found the species [Fe(Tiron)(SCN)(H₂O)₃]^2? and [Fe(Tiron)₂(SCN)(H₂O)]^6?. The formation and the optical properties (^λmax,^? max) are discussed.