EFFECT OF RARE EARTH ADDITIONS ON THE IMPACT FRACTURE OF Cr18Nil8Si2 STEEL

<正> Cr 18 Ni 18 Si 2钢经热处理后的低温冲击断口,其中加稀土的为穿晶断口,而未加稀土的为混合型断口。 试验用钢用高频感应炉冶炼,锭重20kg,锻成15×15mm方棒,再加工成冲击试样。其化学成分如下。稀土的加入是将一号混合稀土合金缚在钢棒上插入熔池。     

Adsorption characteristics of hexadecyl ammonium with different numbers of carbon chains in montmorillonite and the structure of the prepared composites

Journal of Porous Materials - The dynamics and thermodynamics of adsorption of hexadecyl ammonium with different numbers of carbon chains in montmorillonite (Mt) with different layer charge density...     

钢丝绳张紧装置在大行程拖链上的应用

介绍了给DY3000×20m数控机床大行程拖链增设的张紧装置,该装置解决了拖链无法自动复位的问题,使用方便、经济可行。     

异丁烯两段催化氧化制甲基丙烯酸催化剂研究 Ⅰ．异丁烯气相氧化制甲基丙烯醛多元复合氧化物催化剂的研究

本文报导用于异丁烯（叔丁醇）选择氧化制ＭＡＬ（甲基丙烯醛）的多元复合氧化物催化剂的研究结果。同共沉淀法制备的催化剂的活性主要决定于其化学组成，同时受到制备条件的影响。最佳催化剂的主要物相组成为ＰｂＯ３，Ｂｉ２ＭｏＯ３．３、ＮｉＭｏＯ４、Ｓｂ２Ｏ３及ａ－Ｆｅ２Ｏ３小颗粒。在３５５℃，１０００～２５００ｈ－１空速范围，叔丁醇：水：空气＝１：３．３：７（摩尔比）的条件下可获得异丁烯转化率达９６％，ＭＡＬ选择性达８９％的结果。     

下河沉积型瓷石的工艺特性与开发应用的探讨

本文论述了新近在江西下河发现的沉积型瓷石的地质特点、矿石特征、精泥性能、成瓷工艺及其开发应用前景。     

印刷胶带生产中的几个问题

对印刷胶带生产中的几个问题如稀释剂、印刷中参数、涂布工艺等作了简述。     

Formation of metal fog during molten salt electrolysis observed in a see-through cell

Visual observations of several molten salt electrolysis processes were made in a two-compartment, see-through quartz cell. The electrolyses of aluminium, magnesium, lead, zinc, sodium and potassium were studied. The colour of the melt in the anode compartment was pale yellow for fluoride-chloride melts and red for chloride melts, caused by the presence of dispersed anode gases during electrolysis. In the cathode compartment, streamers of metal fog were formed. The colours of the metal fog were purple for aluminium, grey for magnesium, lead and zinc, blue for sodium and green for potassium.The metal fog tended to sink to the bottom of the cell, which indicated that it had a higher density than that of the melt. The metal fog also penetrated into the anode compartment, probable due to convection and diffusion in the melt. The most probable explanation of the nature of the metal fog is that it consisted ofdispersed metal particles. This chemically unstable phase dissolved easily in the melt and was oxidized quickly by the anode gases.     

Engineering all-aromatic polyamide surface from hydrophilic to superhydrophobic and the accelerated strategy

Being a new kind of nanomaterials, aromatic polyamide nanofibers (ANF) have been much highlighted in recent studies. We here demonstrate an isopropyl alcohol (IPA) accelerated chemical cleavage on poly (p-phenylene terephthalamide) chopped fibers, which provides an efficient preparation method of ANF. The comprehensive study on the processes accelerated by different alcohols revealed that the preparation time of ANF in the mixed medium of dimethyl sulfoxide (DMSO)-alcohol (20:1 in volume) was shorten to 45 min and 75 min for methanol (ethanol) and isopropanol, respectively. However, the nanofibers prepared in DMSO-IPA exhibited the minimum in axial and radial dimensions, providing the finest and most uniform diameter of 16 nm. The corresponding ANF films through vacuum assisted filtration also showed the highest tensile strength of 150 MPa, in comparison with those of the ANF films prepared using other alcohols, which were about 110 MPa. Furthermore, ANF/silicon hybrid films were prepared by the ionic ring-opening reaction followed by the alkoxysilane condensation and nanoparticle fabrication. By changing the organo functional groups in the alkoxysilane, the surface of the films were adjustable in a wide contact angle range from 56° (hydrophilic) to 150° (superhydrophobic), suggesting the amendable interfacial properties potential applicable to composite fabrication with most of the resin matrix.     

冷轧工作辊摩擦不稳定分析及其抑制对策

对冷轧机工作辊由于摩擦力引起的垂直、横向振动作了定性分析，指出了它们的危害，提出了预防措施。     

新时期研究生挫折教育略论

加强对研究生的挫折教育,已成为新时期研究生教育的一项非常重要而迫切的任务。研究生挫折教育的途径主要有:培养研究生树立良好的挫折观;将远大志向与正确、切实的短期目标有机结合;研究生导师要将挫折教育作为自身工作的重要职责和内容;要创设挫折情境,加强实践体验;在研究生中积极开展抗挫互助活动;帮助研究生学会自我调适、自我超越、自我教育。