57Fe Mössbauer Spectroscopic Study on the Assembled Iron Complexes

We have measured the lattice distortion around As (acceptor) and Br (donor) in CdTe with fluorescence detected X-ray absorption spectroscopy. We could experimentally verify the lattice relaxation with a bond length reduction of 8% around the As atom as inferred indirectly from ab initio calculations of the electric field gradient performed with the WIEN97 package in comparison with the measured value in a Perturbed Angular Correlation experiment as recently reported. We have complemented our own calculations of relaxation with WIEN97 with calculations using the FHI96md pseudo-potential program, which allows the use of larger super-cell sizes. Encouraged by the good agreement between experiment and model calculation for As in CdTe as well as similarly for the isovalent Se in CdTe, we extended our investigation to Br in CdTe, where the electric field gradient has also been measured, and could not only verify the derived lattice expansion around Br with our EXAFS analysis but additionally observe fractions of Br in the A-center as well as in a DX-center configuration.     

The motion of a gyroscope freely falling into a Schwarzschild black hole

In this note we investigate the motion of the axis of a gyroscope freely falling along the radial geodesic in Schwarzschild space-time. It is shown that the gyroscope's axis rotates to the radial direction in the orthonormal frame as it falls into the black hole.     

Ultrafast Photonic Asynchronous Transfer Mode Switch Based upon Parallel Signal Processing

An ultrafast photonic asynchronous transfer mode (ATM) switch is proposed that incorporates a holographic buffer memory and an optical parallel routing controller. Ultrafast serial-to-parallel conversion of the temporal profiles of optical cells into spatial patterns is used to process optical cells in space in a parallel manner. The spatial pattern of the data payload is holographically recorded as a page in the optical buffer memory. The routing control to establish the switching state consists of header recognition performed by optical matched filtering, followed by control signal generation via reference to a lookup table. The ultimate throughput of the switch is expected to be 103 Tb/s with line bit-rates of 17 Tb/s.     

Positronium as a probe of sorption states of vapor molecules in polymers

Positron lifetime measurements were performed for two different polymers (low density polyethylene and a polyimide 6FDA-TMPD) during sorption of various vapors (n-hexane, cyclohexane, benzene, acrylic acid, methyl acrylate). The vapor sorption affected the long-lived component (ortho-positronium component) in a systematic way regardless of the kind of vapor, i.e. for the polyethylene both the lifetime and the intensity of the long-lived component were enhanced, while for the polyimide they were decreased significantly. These different effects are interpreted in terms of the different aggregation states, i.e. rubbery for the polyethylene and glassy for the polyimide.     

Color-dielectric properties of a ferromagnetic state in quantum chromodynamics

The response of a color-ferromagnetic state (noticed by Savvidy) to small external perturbations is studied by use of the effective action. An electric instability and the electric Meissner effect combine to reveal the color-confining character of the ferromagnetic state.     

Structural elucidation of talopeptin (MK-I), a novel metallo proteinase inhibitor produced by streptomyces mozunensis MK-23

The structure of talopeptin (MK-I), a novel metallo proteinase inhibitor produces by Streptomyces mozunensis MK-23 was elucidated to be 6-deoxy-α-l-talopyranosyloxyphospho-l-leucyl-l-tryptophan.     

Anomalous variation of the exciton Fano-resonance spectra in strongly biased Wannier-Stark ladder

Effects of the Wannier-Stark ladder (WSL) resonance on optical absorption spectra in strongly biased superlattices are theoretically investigated by solving the multichannel scattering problem relevant to the WSL-exciton Fano-resonance. When the bias of an electric field F is applied such that a WSL subband state is energetically aligned with adjacent ones, resulting in strong repulsion (anticrossing) due to Zener resonance, an onset of exciton absorption notably shifts toward the lower energy side. However, just a slight change of F away from the anticrossing leads to a peculiar suppression, lowering the absorption edge. According to a qualitative analytic model, such an anomalous variance is found ascribable to delocalization of WSL subband wave functions across several periods through a mixing of an exciton reduced mass in the region of the potential well with that in the region of the potential barrier.     

Determination of hydroxylated polycyclic aromatic hydrocarbons in airborne particulates by high-performance liquid chromatography with fluorescence detection.

This paper describes a highly sensitive and selective method for the determination of hydroxylated polycyclic aromatic hydrocarbons (PAHs-OH) in airborne particulates. PAHs-OH were extracted from airborne particulates with ethanol by ultrasonication. The extractant was further cleaned up by solid phase extraction (SPE) with an aminopropylsilica cartridge, and subsequently analyzed by reversed-phase high-performance liquid chromatography with fluorescence detection. 2-Hydroxy-1-acetonaphthone was used as an internal standard. By the proposed method, 2-hydroxyfluorene and 1-hydroxypyrene were identified in airborne particulates and their concentrations were determined for the first time.