A vision chip with column-level amplification of optical data signals for indoor optical wireless local area networks

We present a vision chip architecture with column-level photo-amplification of optical data signals for optical wireless local area networks (LANs) to reduce the pixel area. Based on the architecture, we have fabricated a prototype vision chip in a standard 0.8 μm bipolar complementary metal-oxide-semiconductor (BiCMOS) technology. The device offers position detection of other optical transceivers in the LAN and 4-ch concurrent high-speed optical data acquisition. A data rate of 400 Mbps was demonstrated. The pixel size was 125 μm square, which can be shrunk to smaller than around 60 μm square in 0.35 μm or more advanced BiCMOS or CMOS technologies.     

15N NMR study on site-selective binding of metal ions to guanine runs in DNA: a good correlation with HOMO distribution

15N NMR of DNA containing 15N-N7-enriched guanine (G) in the presence of paramagnetic ions (Mn(II) and Co(II)) was investigated. As the concentration of metal ion was increased, 15N NMR signals of the 5'G of GG and the middle G of GGG broadened site-selectively, indicating that electron-donating sites in G runs preferentially localize on the 5'G of GG and the middle G of GGG. The selectivity for G-metal ion interaction observed in this study was in good agreement with calculated HOMO distribution of G runs.     

Relaxation of flexible chains in dilute and non‐dilute systems. Dynamic Monte Carlo results for linear and star chains

A dynamic Monte Carlo algorithm is employed to investigate the dynamics of flexible linear and star chains on a cubic lattice at different concentrations. Some results for similar systems are also obtained with an off‐lattice algorithm. Diffusion coefficient, relaxation times and mean size data are combined into friction‐independent ratios in good agreement with the theoretical predictions from the Rouse theory. The relaxation times and amplitudes corresponding to the Rouse normal modes are analyzed in terms of their variation with the mode order. The end‐to‐end vector correlation times obtained from the simulations for linear chains are compared with the theoretical expression obtained from the Rouse theory. Deviations from this theory are observed for the contribution of the different modes in the non‐dilute systems. Finally, the time correlation function corresponding to a subchain's end‐to‐end vector is investigated. The results also show deviations from the Rouse theory, which are in qualitative agreement with the features observed in data from dielectric relaxation experiments of block copolymers.