Full‐duplex analogue/digital data transmission using lasers coupled to GI fibre and its application

This paper describes a low‐cost version of a full‐duplex optical fibre analogue/digital data transmission link whose practical implementation is simplified by using a pair of laser diodes, each having a built‐in photodiode for monitoring the laser output power, and its application to vibration test data transmission. The transmission link sends digital data of up to 9600 bps in one direction, and analogue data of DC to 100 kHz and image data specified by an NTSC colour video signal in the opposite direction, all at the same time through one GI optical fibre. Being simple in configuration and stable against noise, this type of link has a variety of applications within factory, home and offices. Copyright © 2001 John Wiley & Sons, Ltd.     

High-quality narrow gap (1.52 eV) a-Si:H with improved stability fabricated by excited inert gas treatment

Narrow band gap (1.5 eV) hydrogenated amorphous silicon (a-Si:H) were fabricated by a chemical annealing technique using noble gases (Ar, He, Ne). Although hydrogen content in the film was reduced to 1 atm% and band gap was decreased to 1.52 eV, high photoconductivity and large mobility–lifetime products were maintained and no marked changes in the short-range structure was found. Using these narrow band gap a-Si:H for photoactive layer in n-i-p solar cells, reasonable photovoltaic performances were obtained, i.e., open-circuit voltage of 0.71 V and fill factor of 57%. Also enhanced red response was observed with the 1.58 eV band gap i-layer solar cell prepared on textured substrate.     

Detection of Helicobacter pylori in fecal samples of gnotobiotic mice infected with H. pylori by an immunomagnetic-bead separation technique

By an immunomagnetic-bead (IMB) separation technique, isolation of Helicobacter pylori from gastrointestinal and fecal samples of gnotobiotic mice infected with the microorganism was tried. The isolation rate of H. pylori from stomach samples after IMB separation was not higher than that of direct culture of the samples. After IMB separation of feces, H. pylori was detectable by PCR, although H. pylori was not culturable.     

N-channel MOSFETs fabricated on homoepitaxy-grown 3C-SiC films

We present results of the enhancement mode, n-channel 3C-silicon carbide (SiC) MOSFETs fabricated on homoepitaxy 3C-SiC films. The fabricated devices exhibit excellent gate-controlled linear and saturation regimes of operation. The average effective channel mobility is found to be 229 cm/sup 2//Vs. The breakdown field of the gate oxide is observed at be 11 MV/cm and the subthreshold swing is determined to be 280 mV/decade.     

Postprandial electrogastrographic changes with or without parasympathetic nerve blockade

To investigate the relationship between postprandial electrogastrographic changes and parasympathetic nervous activity, 10 healthy adult males (20 to 29 years old) volunteered for EGG recording in the following conditions: 1) butylscopolamine bromide (scopolamine) administration to block parasympathetic nervous activity; 2) after food intake; and 3) during a postprandial period after the parasympathetic blockade. Power spectral analysis of EGG was performed according to Akaike's autoregressive model. When the parasympathetic nervous activity was blocked, there were no changes in the dominant frequency of the EGG. During the postprandial period, the dominant frequency in EGG increased significantly, and postprandial dip (transient frequency decrease after the food intake) was observed in 8 of the 10 subjects. During the postprandial period after scopolamine administration, the dominant frequency of EGG did not increase, and postprandial dip was observed in only two subjects. These results suggest that the parasympathetic nervous activity is involved in occurrence of postprandial gastric motor function and postprandial electrogastrographic changes.     

基于制动时间间隔的ABS控制策略研究

制动强度大小是影响汽车制动安全性的重要因素.通过对制动过程的分析与仿真,提出了一种基于制动时间间隔为控制参数的ABS控制策略.制动过程中,通过改变制动力作用的时间间隔,使制动力的平均值变化.适应不同路面对制动强度的要求,达到防止车轮抱死,提高汽车制动时车辆的稳定性和操纵性的目的.     

Hybridized hydrogen production system with Fe—I. Photochemical reaction in concentrated phosphoric acid

An attempt was made to carry out the following photochemical reaction, 2Fe²⁺ + I^?₃ + light → 2Fe^3? + 3I^? in concentrated phosphoric acid in order to obtain hydrogen iodide as a gaseous product. By means of the above photochemical, and two other consecutive chemical reactions, water is decomposed into hydrogen and oxygen. Compared to the water-splitting system with dilute sulfuric acid, this system has an advantage of easy separation of hydrogen iodide from the reaction mixture. Experiments are made with various conditions of phosphoric acid, temperature, light intensity and concentrations of iodine.     

Photochemical and thermoelectric utilization of solar energy in a hybrid water-splitting system

A hybrid thermochemical water-splitting cycle using solar energy is proposed and experimental results are presented. The cycle consists of a photochemical reaction conducted in a flat cell with a Fresnel lens and concentrating the remaining solar energy on a thermoelectric generator which produces electric power for the electrolysis steps. The photochemical reaction is:

$\text{2}\text{Fe}{}^{\mathrm{2+}}\text{+}\text{I}{}^{\mathrm{?}}\text{+}\text{light}\text{→2}\text{Fe}{}^{\mathrm{3+}}\text{+3}\text{I}{}^{\mathrm{?}}$

The overall efficiency is estimated to be as high as 15–25%.