Die Identifizierung des Herbicids Chlorpropham

Ohne Zusammenfassung     

All-optical sampling with a monolithically integrated Mach-Zehnder interferometer gate

An all-optical sampler consisting of a polarization-independent monolithic Mach-Zehnder interferometer with integrated semiconductor optical amplifiers and a temporal resolution of 1 ps is presented. As an example, a simple 320-Gbit/s pattern has been successfully sampled, demonstrating the functionality of this scheme for high-bit-rate waveform characterizations in light-wave systems.     

Nuclear quantum effects in calculated NMR shieldings of benzene; a Feynman path integral study

The Feynman path integral Monte Carlo approach has been coupled to the gauge including atomic orbital formalism in order to analyse the absolute magnetic shieldings of the benzene nuclei under the conditions of thermal equilibrium. The Hamiltonian employed in the derivation of ensemble averaged NMR quantities is of the Hartree-Fock type. The basis set used is of 6–31G quality. The spatial delocalization of the atoms leads to a deshielding of both types of benzene nuclei relative to the shieldings experienced at the minimum of the potential energy surface. This deshielding has to be traced back to bond length elongations in thermal equilibrium. The influence of the nuclear fluctuations on the NMR parameters of benzene is quantum driven up to temperatures of 400 K; classical fluctuations are of minor importance in this low-temperature window.     

Measurement of the FeXXV dielectronic recombination rate coefficient in the PLT tokamak plasma

The FeXXV dielectronic recombination rate coefficient associated with the 1s-2p core excitation has been measured as a function of the electron temperature in the range from 0.9–3 keV from the observations of the satellite lines emitted from the PLT (Princeton large torus) tokamak plasma. These measurements are compared with recent theoretical predictions of Bely-Dubau et al. as well as with the approximation formulae of Burgess and Merts et al., and the results of Jacobs et al. Excellent agreement is obtained with the more recent calculations.