Optical neurochip with learning capability

A dynamic optical neurochip with variable synaptic interconnection capability has been reported. A novel type of photodetector called a variable sensitivity photodetector has been developed for the synaptic interconnection of neural networks. It utilizes a metal-semiconductor-metal structure whose quantum efficiency can be modulated by an applied bias voltage. The fabricated dynamic optical neurochip consists of an 8×8 variable sensitivity photodetector (VSPD) array and an 8 line-shaped LED array. It is shown that this device is suitable for learning in neural networks. The application to pattern classification is demonstrated     

Hearing recovery in sudden deafness with profound hearing loss

To more completely describe acromion morphology and its relationship to impingement syndrome, we performed three-dimensional magnetic resonance imaging (N = 111) or computed tomography (N = 27) on 132 symptomatic shoulders. The mean patient age was 46.2 years (range, 14 to 86). Four parameters were evaluated: the angle of anterior slope of the acromion in the midsagittal and lateral-sagittal planes, lateral acromial angulation in the coronal plane, and the presence or absence of medial encroachment in the acromioclavicular joint. Twenty-five asymptomatic age-matched shoulders were used as controls. All imaging data were combined because no significant differences existed between the two imaging techniques. The mean acromion angle was 19.4 degrees in the midsagittal plane and 20 degrees in the lateral-sagittal plane. In the coronal plane, 97 (73%) acromions were neutral and 35 (27%) were downward sloping. Medial encroachment was present in 31 (24%) shoulders. Age distribution from the 2nd to 8th decade demonstrated a consistent and gradual transition from a flat acromion in the younger decades to a more hooked acromion in the older decades that was significant in both the midsagittal and lateral-sagittal planes. Furthermore, a greater percentage of patients were found to have downward angulating acromions with increasing age. Ninety-eight patients (74%) had stage II or III impingement. Of these shoulders, 39 (40%) had type I acromions, 51 (52%) type II, and 8 (8%) type III. Twenty-eight of 33 acromions with coronal lateral downward sloping had impingement, and all 31 shoulders with medial encroachment had impingement.     

Co gas detection by ThO2-Doped SnO2

The selective detection of CO gas by stannic oxide incorporated with ThO2(l − 10 wt%), in the presence of H2 and petroleum gases such as C₃H₈ and iso-C₄H₂ has been studied. Materials mixed with 5 wt% ThO₂ showed high selectivity to CO gas at a sample temperature of 200−250‡C. The effects of hydrophobic or hydrophilic silica present in the samples on the detection sensitivity to CO gas have been investigated. From the results it is apparent that the removal of the hy-droxyl radical from the surface of SnO₂ enhances the sensitivity to CO gas.     

Simple plunge freezing applied to plant tissues for capturing the ultrastructure close to the living state

In order to observe the ultrastructure close to the living state, simple plunge freezing in liquid propane was applied to plant tissues. The method yielded a well-preserved ultrastructure to a depth of up to 40 microm from the surface of the young pea leaves, which were used as the specimen. Within the well-frozen area all membranes appeared smooth and the ultrastructural details of each organelle were similar to those obtained by high-pressure freezing. Several physical connections between the membranes were visualized. The relative simplicity and the satisfactory freezing performance of the method render it suitable for capturing the features of actively functioning cells in routine ultrastructural studies.     

Structural Control of Rashba Spin–Orbit Coupling in In0.52Al0.48As/In0.53Ga0.47As/In0.52Al0.48As Quantum Wells

We investigated the correlation between the Rashba spin–orbit coefficient and potential shape of the quantum wells (QW), where values are experimentally deduced from the weak antilocalization analysis. We studied the gate I–V properties of the QW samples and have obtained results consistent with the potential shapes predicted for these QWs.     

Multiwavelength all-optical TDM switching using a semiconductoroptical amplifier in a loop mirror

We report simultaneous all-optical switching of multiple wavelengths using an optical loop mirror with an asymmetrically placed semiconductor optical amplifier. Switching is shown for 14-wavelength channels (across 14-nm bandwidth) with switching contrast of 10-23 dB     

Improvement of anode oxidation reaction of a fuel cell using ammonium formate with Pt‐Ir catalysis

We have attempted to develop high‐performance and safe fuel cells by using ammonium formate as a solid (powder) fuel. This solid fuel has the potential of safer transportability than liquid fuels such as methanol from the viewpoint of toxicity and flammability. In order to make use of some of the advantages of ammonium formate, we investigated the oxidation characteristics of ammonium formate with respect to a Pt electrode. Cyclic voltammograms indicate that ammonium formate has high oxidation activity with respect to a Pt electrode. We have also found that the oxidation of ammonium formate can be improved by the addition of Ir to Pt catalysts. It is highly likely that ammonium formate will be useful as a solid (powder) fuel for polymer electrolyte membrane (PEM) fuel cells. This new fuel will promote the development of safe fuel cells for PEM. © 2010 Wiley Periodicals, Inc. Electr Eng Jpn, 174(4): 45–50, 2011; Published online in Wiley Online Library ( wileyonlinelibrary.com ). DOI 10.1002/eej.21043     

Growth and led evaluation ofN-type conductive lec gaas co-doped with in and si

Dislocation-free and low dislocation densityn-type conductive GaAs crystals, 50 mm in diameter, were grown by the In and Si co-doping LEC technique. Two-dimensional LED arrays were fabricated on substrates obtained from these crystals by the MOCVD technique and the influence of the In doping on the LED characteristics was examined. The light output power of LEDs fabricated on co-doped substrate with an In concentration of 1 ×10²⁰atoms/cm³ are low and are non-uniformly distributed, as compared with the boat-grown substrate, even though the co-doped substrate is dislocation-free. However, the LED properties of a substrate with an In concentration of 2 × 10¹⁸atoms/cm³ are the same as those of a boat-grown substrate. The light output power of the LEDs becomes higher as the In concentration in the substrate decreased.     

CO2激光直接钻孔工艺的前后处理

近几年,电子产品朝轻,薄,短,小化迅速发展,印制线路板也随着这股潮流朝向高密度封装方向发展。尤其是积层板总数的增加和导通孔以及连接盘的小径化也日益显著。对于积层线路板而言,用来加工层间连接的盲通孔(BVH)的激光方法取决于导通孔和连接盘径。激光器分为CO2激光和UV-Yag激光两种。导通孔径为60μm以上时,则一般用CO2激光加工。由于铜在CO2激光的波长(9.3μm～10.3μm)领域中的吸收比很低,因此"保形法"(在表面铜箔上,蚀刻出需要的加工孔径(开铜窗),再以激光打掉树脂)成为了现在的主流。然而,由于保形法需要蚀刻开铜窗,因此增加了形成图形的工序,而且导通孔的定位取决于下层的定位标记,容易发生错位。随着积层板层数的增加,导通孔和连接盘的小径化发展,越来越需要提高加工速度和定位精度。因此,同时对铜和树脂进行加工的"直接钻孔法"开始被关注。直接钻孔法是根据格柏数据进行导通孔的定位,因此,即使导通孔/连接盘径越趋小型化,也不会发生错位,是一种能够推进多层化,高密度化的先端技术。本文讲述了以直接钻孔法形成高可靠度导通孔时所需的技术和药品。     

Preparation of mesoporous silica replica using ordered mesoporous carbon by vapor phase transport of silica source

A new vapor phase transport (VPT) technique to prepare an inverse silica replica of an ordered mesoporous carbon was developed. Tetraethyl orthosilicate (TEOS) was infiltrated in mesoporous carbon CMK-3 as the hard template at 180 °C for 48 h under an autogenous pressure in an autoclave in the presence of water. The samples obtained by removal of CMK-3 retained structural regularity of CMK-3 with little shrinkage of framework, which were characterized by SAXRD, N₂ adsorption, TG-DTA, and SEM. Influence of preparation temperature on the loading amount of silica was investigated. The multi-step replication process was monitored by characterizing the replicated materials as well as intermediate composites.