Transport and Cu NMR studies of charge and spin dynamics in PrBa2Cu4O8

The charge and spin dynamics in PrBa₂Cu₄O₈ are investigated by means of transport and Cu NMR measurements. The magnetoresistance was found to be very small at high temperatures and increase rapidly with decreasing temperature below 100 K, which may be ascribed to the dimensional crossover from one to two dimensions in the charge transport in the CuO double chains. While the NMR signal from the chain Cu sites persists down to 4.2 K without any appreciable line broadening, the signal from the planar Ce sites disappears below 250 K indicating the long-range antiferromagnetic order of plane Cu moments. This is consistent with the view of metallic conduction along the quasi one-dimensional CuO chains.     

Hardware neural network models of CPG and PWM for controlling servomotor system in quadruped robot

This paper discusses the pulse-type hardware neural networks (P-HNNs) that contain a central pattern generator (CPG) and a pulsewidth modulation (PWM) servomotor controller and the application to quadruped robots. The purpose of our study is mimicking the biological neural networks and reproducing the similar motion of the living organisms in the robot. The CPG of the living organism generates the walking rhythms. We mimicked this CPG by modeling the cell body and the synapse of the living organism. The developed CPG composed of the P-HNN output four pulse signal sequences and the four outputs are introduced to each leg of the quadruped robot. On the other hand, the angle of the servomotor is controlled by the PWM. The PWM is obtained by modeling the axon of the living organism. The CPG and the PWM servo control system perform the walking motion of the quadruped robot. Moreover, the gate pattern change of quadruped animals is reproduced by these P-HNNs.     

Mechanism of water adsorption capacity change of bamboo by heating

The water adsorption capacity of moso bamboo (Phyllostachys pubescens) heated at 200 °C in air for various times was examined. The samples were subsequently placed in various humidities at 20 °C to obtain relevant isotherms. They were analyzed using the Hailwood and Horrobin theory, derived for hydrophilic macromolecules, and the Dubinin and Radushkevich theory, previously used to describe the behavior of microporous carbons. The results show that the water adsorption capacities of the samples changed after heating for 2 to 5 hrs, and imply that over this time the number of hydroxyl groups decreased markedly while the number of micropores formed increased.     

Surface features of uniaxial tensile fractures and their relation to rock anisotropy in Inada granite

Uniaxial tensile fractures parallel to the rift, grain and hardway planes were formed in Inada granite. Most of the fractures split the rock-forming mineral grains as transgranular paths under microscopic observations. The surface topography of the fractures was measured by the stereo-photogrammetric technique, and is different in different orientations. The rift-parallel uniaxial fracture has the smoothest surface, and the grain-parallel fractures are smoother than hardway-parallel fractures. The mineral compositions are also different on the failed surfaces of different directions. The rift-parallel fractures have almost the same constituent mineral ratio as the parent rock. However, the grain-parallel fractures pass preferentially through feldspar grains, and contain less quartz grains as compared to the bulk composition of the parent rock. In addition, it is remarkable on hardway-parallel fractures. It is considered that the differences of surface topography and mineral compositions are caused by preferred orientations and spatial distributions of pre-existing microcracks in Inada granite.     

Dynamically shift-switched dataline redundancy suitable for DRAMmacro with wide data bus

A novel dataline redundancy suitable for an embedded DRAM macro with wide data bus is presented. This redundancy reduces the area required for spare cells from 6 to 1.6% of the area required for normal cells and improves chip yield from 50 to 80%. In addition, it provides a high-speed data path. An embedded DRAM macro adopting the redundancy achieves 200-MHz operation and provides 51.2-Gbit/s bandwidth. It has been fabricated with 0.25-μm technology     

Impact of surrounding gate transistor (SGT) for ultra-high-densityLSI's

A transistor with compact structures for future MOS devices is discussed. This transistor, whose gate electrode surrounds the pillar silicon island, reduces the occupied area for all kinds of circuits. By using this transistor, the occupied area of the CMOS inverter can be shrunk to 50% of that using planar transistors. Other advantages, such as steep cutoff characteristics, very small substrate bias effects, and high reliability, are discussed. Its structure, which allows for the enlargement of gate-controllability to the channel and electric field relaxation at the drain edge, is described. The advantages of this SGT for large-scale integration (LSI) devices is discussed     

Low-loss high-silica single-mode channel waveguides

Low-loss high-silica single-mode channel optical waveguides of 0.1 dB/cm have been fabricated on crystal silicon substrates with fibre coupling losses of less than 0.05 dB by flame hydrolysis deposition and reactive ion etching. Directional couplers have also been fabricated with excess loss of 0.5 dB by this waveguide fabrication technique.     

Novel broad-band optical switch using silica-based planar lightwavecircuit

Novel wavelength-insensitive thermooptic switches which use silica-based planar lightwave circuits are proposed and successfully demonstrated. The fabricated switch has an extinction ratio of more than 17 dB over a 1.25-1.65 μm wavelength range     

Direct action of nitric oxide on osteoblastic differentiation

The effect of nitric oxide (NO) on osteoblastic differentiation was examined in cultured mouse osteoblasts. Interleukin-1beta and tumor necrosis factor-alpha expressed inducible NO synthase gene with little effect on constitutive NO synthase gene. These cytokines increased NO production, which was inhibited by L-NMMA pretreatment, and decreased alkaline phosphatase (AIPase) activity, which was not restored by L-NMMA. Furthermore, NO donors, sodium nitroprusside and NONOate dose-dependently elevated AIPase activity and expression of osteocalcin gene. These results suggest that NO directly facilitates osteoblastic differentiation and the cytokine-induced inhibition of AIPase activity is mediated via mechanism other than NO.     

5 GHz-spaced, eight-channel, guided-wave tunable multi/demultiplexer for optical FDM transmission systems

A 5GHz-spaced, eight-channel, guided-wave tunable multi/demultiplexer for optical frequency-division-multiplexing (FDM) transmission systems is demonstrated. It is constructed with high-silica channel waveguides and thin-film heaters loaded on the waveguides for frequency tuning