船用柴油机NOx等有害排放气体的评价及处理研究--燃料喷射系统对乳化燃料在船用柴油机上使用的影响及脱硝装置的适用性

对原试验用柴油机的燃料喷射系统进行了改造。改造后的燃料喷射系统不仅可降低 NOx 的排放 ,而且使高加水率乳化燃料的使用成为可能。但另一方面 ,在低负荷时 ,使用乳化燃料不但不能获得预期的降低 NOx 排放效果 ,反而使其它有害排放增加。所以 ,也对降低 NOx 排放方法之一的脱硝装置进行了探讨 ,对其在船用柴油机上的适用性进行了试验 ,并获得了较好的效果     

氧化物冶金技术的最新进展及其实践

文中介绍了氧化物冶金技术提出的背景,该技术的主要内容和采用该技术对钢的组织、性能的影响.总结了该技术近十几年来在利用夹杂物钉扎晶粒的高温长大和形核晶内铁素体(特别是其机理探讨)方面的相关研究,介绍了国外一些钢铁公司在大线能量焊接过程中所开发的该领域的新技术和新应用,同时介绍了氧化物冶金技术在焊接以外的凝固、压力加工、非调质钢和厚板生产等过程中的研究和应用的最新进展.文末展望了该技术的发展趋势.     

Effect of Seed Layer on the Orientation of Zinc Oxide Film on Silicon Substrate

1. IntroductionZinc oxide films have been attracting more and moreattention because of their high diffractive index, low resis-tance, and photoluminescence properties, and are beingused as transparent electrodes, basis material for opti-cal wave guide devices, gas sensors and so on. Manymethods have been developed to prepare ZnO films, suchas chemical vapor deposition[1], reactive evaporation[2],pulsed laser ablation[3], sputtering[4], spray pyrolysis[5]and hydrothermal method[6]. There are a…     

Effect of Microstructure on the PTCR Effect in Semiconducting Barium Titanate Ceramics

The microstructural influence on the PTCR effect in semiconducting barium titanate ceramics was studied and a method for preparing the ceramic bodies exhibiting a PTCR effect of more than seven orders of magnitude was established. Commercial barium titanyl oxalate was used as a starting material and Sb₂O₃ was added as a doping substance. The average grain sizes of the ceramic bodies prepared were 2 to 5 μm over a sintering range of 60 to 92%, to examine in detail the microstructural influence on the PTCR effect. No extra element, such as Mn or Cr, was added to develop the PTCR effect in the present PTCR materials.     

Isothermal precipitation behavior of copper sulfide in ultra low carbon steel

Copper and sulfur are typical residual elements or impurity elements in steel.Sufficient removal of them during steelmaking process is difficult for copper and costly for sulfur.Utilization of copper and sulfur in steel, especially in steel scrap,has been an important issue for a long period for metallurgists.Copper and sulfur may combine to form copper sulfide,which may provide a prospect to avoid the detrimental effects of copper and sulfur in steel.Unfortunately the formation mechanism of copper sulfide in steel has not been completely clarified so far. In the present paper,solution treatment of samples containing copper and sulfur are firstly performed at 1623 K for 2.7×10~3 s followed by quenching into water.The samples are then isothermally heat-treated at 673 K,873 K, 1073 K,1273 K and 1373K for different time followed by quenching into water again.The size,morphology, constituent and crystallography of sulfide precipitates in these samples are investigated by scanning electron microscope(SEM) and TEM equipped with EDS.Fine copper sulfides(less than 100 nm) are observed to coexist with silicon oxide in samples even isothermally heat-treated at 1 373 K for 1.44×10~4 s;Film-like copper sulfides are generally observed to co-exist with iron sulfide in all samples;Plate-like copper sulfides are observed especially in sample isothermally heat-treated at 1 073 K for 1.44×10~4 s.The formation mechanisms of these copper sulfides have been discussed.     

Polymer Surface Treatment by Atmospheric Pressure Low Temperature Surface Discharge Plasma： Its Characteristics and Comparison with Low Pressure Oxygen Plasma Treatment

The polymer treatment with a low-temperature plasma jet generated on the atmospheric pressure surface discharge （SD） plasma is performed. The change of the surface property over time, in comparison with low pressure oxygen （O2） plasma treatment, is examined. As one compares the treatment by atmospheric pressure plasma to that by the low pressure O2 plasma of PS （polystyrene） the treatment effects were almost in complete agreement. However, when the atmospheric pressure plasma was used for PP（polypropylene）, it produced remarkable hydrophilic effects.     

氧化物冶金技术的最新进展及其实践

介绍了氧化物冶金技术提出的背景,该技术的主要内容和采用该技术对钢的组织、性能的影响.总结了该技术近十几年来在利用夹杂物钉扎晶粒的高温长大和形核晶内铁素体(特别是其机理探讨)方面的相关研究.介绍了国外一些钢铁公司在大线能量焊接方面所开发的该领域的新技术和新应用,以及氧化物冶金技术在焊接以外的凝固、压力加工、非调质钢和厚板钢生产等过程中的应用及相关研究的最新进展,并展望了该技术的发展趋势.     

THERMAL-MECHANICAL LOW-CYCLE FATIGUE UNDER CREEP-FATIGUE INTERACTION ON TYPE 304 STAINLESS STEELS

Abstract— In this study, in-phase and out-of-phase thermal fatigue tests at the temperature ranges of 473–823 and 573–873 K were carried out on three kinds of 304 stainless steel as well as isothermal low-cycle fatigue tests at 823 and 873 K, in order to investigate the properties of thermal fatigue strength under creep-fatigue interaction. Based on the relation between the fatigue life and the failure mode, the time-dependent effect on the fatigue life was discussed. Also, an attempt was made to apply the strain range partitioning method to the thermal fatigue life prediction. It is difficult to evaluate the thermal fatigue life at high temperatures simply from the isothermal fatigue life under the same strain condition. It was also found that an unbalanced creep strain during tensile loading, which increased the number of intergranular cracks, gave the largest damage to the material. By the strain range partitioning method, it was possible to predict the isothermal fatigue life and the thermal fatigue life at the low temperature range within a factor of 1·5. On the other hand, the thermal fatigue life at the high temperature range could only be predicted within a factor of 3. However, further detailed investigations are required on the technique of partitioning the inelastic strain range and predicting the effects of dynamic strain ageing and recovery during strain holds.     

船用发动机有害排放气体的评价及处理研究--燃料性质和输出轴扭矩变化对发动机排放特性的影响

为了评价船用发动机有害气体的排放,本文从燃料的性质着手,较为详细地对不同性质的１３种燃 料进行了研究,并在一台中型四冲程船用柴油机上进行了试验,测定了各种有害排气的浓度、发动机的 性能和燃烧特性,对燃料的性质与排放之间的相关性进行了探讨。进一步调查研究了柴油机运转工况的 不同及输出轴扭矩的变化对ＮＯｘ排放的影响。由试验结果可知：对于周期性输出扭矩的变化,ＮＯｘ的排 放也发生周期性的变化。但是,柴油机在高输出区域运转时,随着扭矩增加所换算的ＮＯｘ浓度呈减小的 趋势;反之,在低输出区域运转时,呈增加的趋势;输出扭矩周期性变化时的ＮＯｘ。的浓度可以用与其相 对应的平均负荷状态的ＮＯｘ浓度处理。