Oxidation of Hastelloy-XR Alloy for Corrosion-Resistant Glass-Coating

The oxidation behavior of Hastelloy-XR alloy was investigated to obtain the optimum surface condition for corrosion-resistant glass-coatings. The surface morphology of oxide scales changed significantly with variation of temperatureand oxygen partial pressure (po2 ). The oxidation kinetics was mainly parabolic independent of oxidation conditions.The oxide scales were consisted of inner Cr2O3 and outer spinel layers. The phase component of spinel layers wereMn1.5Cr1.5O4 and (Mn,Ni)(Cr,Fe)2O4 for the oxygen partial pressures po2<10 kPa and po2>10 kPa, respectively.The optimum oxidation condition to obtain an oxide scale for well-adhered glass-coating to the substrate was 1248 Kand po2 =0.01 kPa for the oxidation time of 43 ks.     

钢表面化学气相沉积TiC晶体的择优取向

本文用化学气相沉积(CVD)法,以TiCl_4-CH_4-H_2为原料气体,在不锈钢表面获得了致密的TiC膜.研究了TiC的成膜速度、表面形貌和晶体择优取向与沉积条什的关系.结果表明,沉积温度T_(dep),碳钛比CH_4/TiCl_4强烈地影响了TiC的成膜速度、表面形貌和晶体择优取向.CH_4/TiCl_4低时,TiC晶体的择优取向为(220):而CH_4/TiCl_4高时,TiC晶体的择优取向为(200).TiC晶体的择优取向主要取决于气氛中活性碳的平衡浓度。     

适合中高频应用的NFM系列IGBT模块

针对医疗仪器和电焊机等市场领域对中高频开关应用的需求,三菱电机开发了NFM系列中高频IGBT模块。本文分析了电流谐振逆变器在两种不同工作模式下的波形和特征,然后详细介绍了NFM系列模块设计中采用的关键技术,包括IGBT硅片、超高速续流二极管(Free Wheeling Diode,简称FWD)、低电感封装技术等,并指出这种模块在中高频开关应用时在低损耗方面的优越性。     

Oxidation of CVD Si3N4 at 1550° to 1650°C

A thermo gravimetric study of the oxidation behavior of chemically vapor-deposited amorphous and crystalline Si₃N₄ (CVD Si₃N₄) was made in dry oxygen (0.1 MPa) at 1550° to 1650°C. The specimens were prepared under various deposition conditions using a mixture of SiCl₄, NH₃, and H₂ gases. The crystalline CVD Si₃N₄ indicated a parabolic oxidation kinetics over the whole temperature range, whereas the amorphous CVD Si₃N₄ changed from a parabolic to a linear law with increased temperature. The oxidation mechanism is discussed in terms of the activation energy for the oxidation and the microstructure of the formed oxide films.     

Effect of Ba Filling Fraction on Thermoelectric Properties of p-type Ba_yFe_(1.6)Co_(2.4)Sb_(12)

1　ＩｎｔｒｏｄｕｃｔｉｏｎＴｈｅｅｌｅｃｔｒｉｃａｌｔｒａｎｓｐｏｒｔｐｒｏｐｅｒｔｉｅｓ (ｃｏｎｄｕｃｔｉｏｎｔｙｐｅ ,ｃａｒｒｉｅｒｃｏｎｃｅｎｔｒａｔｉｏｎ ,ｃａｒｒｉｅｒｍｏｂｉｌｉｔｙ ,ｃａｒｒｉｅｒｅｆｆｅｃｔｉｖｅｍａｓｓ)ａｎｄｔｈｅｔｈｅｒｍａｌｔｒａｎｓｐｏｒｔｐｒｏｐｅｒｔｉｅｓ (ａｔｏｍｄｉｓ ｐｌａｃｅｍｅｎｔｐａｒａｍｅｔｅｒ ,ｍｅａｎｆｒｅｅｐａｔｈｏｆｐｈｏｎｏｎ ,ｌａｔｔｉｃｅｔｈｅｒｍａｌｃｏｎｄｕｃｔｉｖｉｔｙ)ｏｆｆｉｌｌｅｄｓｋｕｔｔｅｒｕｄｉｔｅｃｏｍｐ…     

太阳能光伏发电系统发电量的预测方法

本文介绍太阳能光伏发电系统发电量的两种预测方法——日本工业标准中的预测方法和在模拟计算软件中使用的三维模拟计算法。     

日本住宅用太阳能光伏发电系统介绍

本文通过介绍日本长野县Y先生住宅太阳能光伏发电系统,供业界了解日本住宅用太阳能光伏发电系统的系统设置、成本、实际发电量、卖电价格等内容。     

Alpha-Helical Structure of Fish Actomyosin: Changes during Setting

Participation of the α-helix in setting was investigated using circular dichroism. The α-helicity of the actomyosin from eight species of fish decreased during incubation at 30°C or at 40°C. The extent and pattern of decrease differed among species. When rate of decrease was plotted vs rate of increase in strength of gel preincubated at 30°C or at 40°C, the two factors correlated closely. We propose that the unfolding of α-helix initiated setting.     

Difference of histology and elemental composition of the cervical enamels among human permanent teeth

The purpose of this study is to clarify the difference of histology and elemental composition of the cervical enamels among the human permanent teeth. The re-ground surfaces at the cervical enamels of them were observed under scanning electron microscopy (SEM). The contents of seven elements were analyzed quantitatively with electron probe microanalyzer (EPMA). The widths of the rod sections at the cervical enamels were larger than those at the cuspal enamels. The rod sections at the mesial cervical enamels in the incisors were more obscure and more decayed by acid solution than those in the premolars and molars. The calcium and phosphorus contents of the cervical enamels were significantly lower than those of the cuspal enamels. The carbon content of the cervical enamels was significantly higher than that of the cuspal enamels. The calcium and phosphorus contents of the cervical enamels were the significantly highest in the premolars. The carbon and sodium contents of the cervical enamels were significantly highest in the premolars. It is thought that the calcification level is lower, while the content of organic matter is higher at the cervical enamels than those at the cuspal enamels. It is considered that the sodium causes high calcification.