关键词： Emulsions   Sodium dodecyl sulfate   Surfactants   Materials   Polymers  

摘要： The feasible control of the microstructures of porous polymeric materials has been studied by polymerization of monomer(s) containing bicontinuous microemulsions. Microstructures of the resulting polymeric materials can be varied by incorporating a different weight ratio of a nonpolymerizable surfactant, sodium dodecyl sulfate, and a polymerizable surfactant, sodium 11-(N-ethylacrylamido)undecanoate. The pore sizes in the materials are the water-filled spaces between the incompletely coalesced spherical aggregates, and they are regulated by the size of these aggregates. The morphology of the polymeric materials was examined by field emission scanning electron microscopy. The thermal analysis of the polymeric materials was also investigated, and a possible mechanism for microstructural modification is discussed.

关键词： 热处理   晶化   纳米粉   氮化硅   复合陶瓷   碳化硅  

摘要： 本文在１４７３～１９７２Ｋ温度范围内对激光合成的、平均粒径为３０ｎｍ的非晶Ｓｉ－Ｎ－Ｃ粉进行热处理（ｌａｔｍ．Ｎ２，１ｈ）；研究了粉体的晶化及微结构变化，结果表明，纳米非晶Ｓｉ－Ｎ－Ｃ粉具有短程有序的亚稳结构，此亚稳结构在＞１５２３Ｋ发生稳定团相分离，在１７７３Ｋ开始形成α－Ｓｉ３Ｎ４；β－ＳｉＣ，此时粒子间出现明显的表面扩散形成粒子簇；到１８７３Ｋ晶化加剧，α－Ｓｉ３Ｎ４和β－ＳｉＣ明显增多，并有少量的石墨碳形成。在１７７３～１８７３Ｋ，由固相分离形成α－Ｓｉ３Ｎ４／β－ＳｉＣ纳米复合结构。

关键词： 微型   电子机械系统   MEMS  

摘要： 一种多功能微型电子机械系统谢国章一、引言微型电子机械系统（ＭＥＭＳ）是德国学者于８０年代末提出的概念，意指由微机械与微电子集成所构成的微型结构，具有小型、可靠、性能优越、生产成本低等优点，既有微电子的处理功能，又有微机械的传感与执行功能，是一全智能系...

关键词： 高温超导   晶界   氧序   薄膜   超导材料  

摘要： 报导了高Ｔｃ材料的透射电镜研究。结合材料的物理性能，对ＹＢａ２Ｃｕ３Ｏｘ中氧的含量及有序、ＹＢａ２Ｃｕ３Ｏｘ融熔织构材料和Ｂｉ２Ｓｒ２ＣａＣｕ２Ｏｘ／ＭｇＯ复合材料中的晶界，以及高Ｔｃ薄膜和多层膜的结构进行了分析。

关键词： Superalloys  

摘要： This investigation examines the effect of thermal cycle on the microstructural development in a powder metallurgy (P/M) superalloy braze material. Using a vertical quench furnace, samples were quenched at various stages within the heat treatment. Microstructures were analyzed using optical microscopy and an electron microprobe. The results show that borides having a blocky morphology are stable at all temperatures, both compositionally and morphologically. Script phase undergoes a drastic change in chemistry;however, it remains morphologically stable throughout. The chemical analysis of the microstructure supports the conclusion that the extended heat treatment, which is employed in industry to homogenize the microstructure and dissolve detrimental phases, does not have a significant effect in preventing these phases from forming. By using shorter times at elevated temperatures, similar microstructures can be produced.

关键词： charge transfer materials   microstructure   solidification kinetics   thermal analysis   electron donors and accepters  

摘要： Microstructural and thermal studies on charge-transfer materials have been reported in this paper. Optical microphotographs of pure donors, accepters and their complexes have been obtained. Thermal analysis has been done to learn about their thermal stability and stoichiometries. Th solidification kinetics has been studied to learn about the role of heat treatment on these materials. Powder X-ray diffraction data and optical microphotographs have been obtained to evolve structure-microstructure-physical property correlations. It has been shown that these aspects, hitherto neglected, should be seriously pursued for developing a commercially viable process for organic electronic materials.

关键词： 纳米材料   多层膜   微结构   衍射特性   同步辐射   辐照   稳定性  

关键词： Optical materials  

摘要： A brief progress report is provided on (1) the fabrication and integration with high speed VLSI circuitry of high frequency organic electro-optic modulators and (2) preparation of polymer microspheres, containing one or more layers of covalently coupled chromophores, capable of supporting morphological resonances.

关键词： 陶瓷   刀具   材料   显微结构   力学性能  

摘要： 本文研究了Ａｌ２Ｏ３－Ｔｉ（Ｃ，Ｎ）体系新型陶刀具材料的力学性能与显微结构。该新体系材料的晶粒细化，双骨架结构穿插均匀、连续、牢固．随硬质相Ｔｉ（Ｃ，Ｎ）含量的增加，晶粒、裂纹尺寸减小。新材料的主要力学性能较常用的Ａｌ２Ｏ３－Ｔｉ（Ｃ，Ｎ）体系材料有明显提高。

关键词： 原位复合材料   反应生成   拉伸性能   位错强化   复合材料的界面微结构  

摘要： 原位金属基复合材料(in situ MMCs)由于具有很多的优异性能,而且制备过程比较简单,制作成本低,已成为一种有前途的金属基复合材料(MMCs)之一.该文的研究目标是研制具有优异力学性能、造价低、用途广、易于工业化的新型原位金属基复合材料-TiC-AlN/Al.内容包括较经济有效的原位反应自生技术、反应合金体系的优化选择、反应生成相的预测和确定、反应过程的控制、自生相分布均匀度的改善、自生相的形核与长大机制及界面微结构等.作者利用含C、N元素的混合气体与Al-Ti-Mg合金液体直接反应,在电磁和气动搅拌条件下,首次制取了原位TiC-AlN/Al复合材料.这种复合材料的结构特点是Al基体中自生出的两种增强体,且每一种增强体本身都具有良好的性能.如TiC具有高硬度、高强度、高耐磨、高弹性模量等优异性能;AlN具有好的热导性(是Al<,2>O<,3>的10倍),小的热膨胀系数(是Al<,2>O<,3>的1/2)相当低的密度,高硬度及高弹性模量等优异性能.通过改变冷却速度和搅拌力度可以获得不同形状的增强体,例如TiC,炉冷时为晶须状(TiCw),水冷钢模浇铸时为颗粒状(TiCp).研究结果表明TiC-AlN/Al的生成是由于TiC和AlN在Al-Ti-Mg合金液体中反应成核和长大的结果.反应温度下,合金液中的Mg对AlN的生成有催化作用且能防止AlN区域性转变,以保证体反应的进行.TiC、Al自生颗粒能交替弥散分布于Al基体中是由于电磁搅拌和气动搅拌的结果.