相容剂对PS／PP共混合金混容形态和性能的影响

研制了马来酸酯接枝聚丙烯相容剂，并将其用于聚苯乙烯／聚丙烯的共混改性；通过力学性能测试、透射电镜分析、差示扫描量热分析等方法研究了相容剂对ＰＳ／ＰＰ合金的混容形态和力学性能的影响。结果表明：相容剂的加入，使ＰＳ／ＰＰ由不相容的独立聚集的两相变为相畴很小的细分散相，共混高分子的链段运动也表现为趋于均相结构的运动方式。加入相容剂后共混材料的冲击强度有明显提高，拉伸强度也有所上升。相容剂的含量对性能也有较大影响，相容剂用量为８％时，力学性能最好，从ＤＳＣ测试中可以看到此时共混物趋向均相体系；继续增大相容剂用量，合金的力学性能反而下降。     

PA66/UHMWPE合金的力学性能和微观结构研究

制备了PA66／uHMwPE／HDPE-g-MAH共混合金，并对其力学性能和微观结构进行了研究。结果表明，随着UHMWPE质量分数的增加，共混合金常温和低温下的缺口冲击强度都显著提高，拉伸强度和拉伸模量下降，但仍能保持较高的力学性能；添加了UHMWPE的PA66合金的断裂面有大量的空穴产生和应力发白现象。     

Corrosion protection of magnesium ZM 21 alloy with polyaniline–TiO2 composite containing coatings

A polyaniline–TiO₂ composite (PTC) was prepared by oxidative polymerization of aniline in phosphoric acid with ammonium persulphate, in the presence of TiO₂. The composite was characterized by spectroscopic methods. An acrylic paint containing the PTC was prepared and the coating formed on magnesium alloy was evaluated by electrochemical impedance spectroscopy after exposure to salt spray test for a period of 250 h. The coating containing the PTC was found to protect the magnesium alloy more efficiently than the coating containing polyaniline.     

《铁碳合金相图》的教学探究

本文对Fe-Fe3C相图和它的教学设计进行了全面分析,特别用简而易懂的5单7双3线9点方法对铁碳合金相图进行了详细的分析,使得原本枯燥难懂的理论变得形象生动。     

KINETICS OF GROWTH OF MAGNESIUM HYDROXIDE CRYSTALS

The kinetics of growth of Mg(OH)₂, seed crystals at 298, 308 and 318 K from an a~ueous supersaturated solution of initial concentrations of Mg(OH)₂ 0,48, 0.60 and 0.73 mol-3 were determined. The growth was followed by measuring the conductivity of a seeded system as a function of time. The growth kinetics satisfied a first order kinetic equation. Within the examined range of variables the kinetic constant is independent of temperature and the initial concentration and dependenl on the surface area of seeds added at the start of the experiment. The growth of crystals under the studied conditions is controlled by the surface reaction mechanism.     

Control of molecular weight distribution of isotactic polypropylene obtained by a MgCl2-supported TiCl4 catalyst

It is of great importance in propene polymerization to control molecular weight and molecular weight distribution as well as isotacticity. Propene polymerization was carried out with an isospecific MgCl₂/TiCl₄-Cp₂TiMe₂ catalyst in the presence of various kinds of external Lewis bases. It was found that the molecular weight distribution of the isotactic polymer could be controlled while retaining high activity, high isospecificity and high molecular weight only by changing the kind and/or amount of the Lewis bases. © 1997 Elsevier Science Ltd.     

PP/M-HOS/POE三元复合材料的界面改性与力学性能

采用马来酸酐接枝聚丙烯(PP-g-MAH)及马来酸酐接枝乙烯-1-辛烯共聚物(POE-g-MAH)为界面相容剂，利用熔融共混法制备PP／镁盐晶须(M—HOS)／POE三元复合材料，研究了PP-g-MAH及POE-g-MAH的用量及配比、M-HOS和POE的用量对三元复合材料力学性能的影响。结果表明：当PP／M-HOS／POE的质量比为100／10／20时，PP-g-MAH的最佳用量为3份；利用PP-g-MAH及POE-g-MAH作为复合相容剂可同时改善M-HOS与PP和POE的界面相容性，促进POE、M-HOS对PP的增韧补强作用，使三元复合材料的力学性能得到了明显的改善。     

LC4铝合金高温变形规律的探讨

研究LC4铝合金的高温变形规律 ,拟合出具有较高精度的高温本构模型。并应用所开发的一套数值模拟软件系统 ,对LC4铝合金的高温压缩规律及压缩过程进行了分析。     

高压凝固对Al-Mg合金枝晶形态的影响

利用OLYMPUS光学显微镜研究了高压凝固对Al-9．6Mg合金枝晶形态的影响。结果表明，与常压下典型的破碎的粗大枝晶组织相比，高压凝固条件下，枝晶臂较完整，二次枝晶间距减小，并且大部分一次枝晶臂增长。从高压对成分过冷和热过冷的影响及溶质扩散角度探讨了枝晶形态的变化机理。高压这种极端凝固条件为改变合金的组织形态提供了一种新途径。     

Localized swelling of Fe-Cr-Ni alloy rollers in high-temperature applications

Localized swelling has been observed in 24Cr-24Ni-Nb steel transportation rollers used in the normalizing furnace of a plate mill after prolonged service at high temperature. Due to high localized thermal and mechanical stresses, the chromia layer formed on the roller surface ruptures, exposing the roller substrate to furnace oxygen. Oxidation of second-phase carbides results in the formation of carbon monoxide at very high partial pressure. This leads to formation of voids, leading in turn to localized swelling of the roller material.