Effect of Addition of Oxides on Low-Temperature Oxidation of Molybdenum Disilicide

A type of aluminosilicate that has a good wetting property for molybdenum disilicide (MoSi₂) was added to a MoSi₂ matrix to study the effects on the microstructure and low-temperature oxidation. It was found that the composites had not only good low-temperature oxidation resistance but also high thermal shock resistance when the added oxides formed a network microstructure in the matrix. There was no appreciable oxidation gain for MoSi₂/oxide composites with a network microstructure at 773 K for 2500 h. The results indicate that microstructure design is a simple and effective solution to preventing the low-temperature oxidation of MoSi₂.     

A new core–shell type fluorinated acrylic and siliconated polyurethane hybrid emulsion

A novel core–shell type fluorinated acrylic and siliconated polyurethane (FSiPUA) hybrid emulsion was prepared by seeded emulsion polymerization using siliconated polyurethane (SiPU) as a seed and forming the structure with SiPU as a shell and the copolymer of butyl acrylate (BA) with 2,2,2-trifluoroethylmethacrylate (TFEMA) as a core. SiPU was synthesized using isophorone diisocyanate (IPDI), polytetramethylene ether glycol (PTMG), polypropylene glycol (PPG), dihydroxybutyl-terminated polydimethylsiloxane (PDMS), dimethylol propionic acid (DMPA), 1,6-hexanediol (HDO) and triethylamine (TEA). The contents of siloxane and fluorine were determined according to the feed ratio. Fourier transform infrared spectroscopy (FTIR) was used to identify the chain structure of SiPU and FSiPUA. Investigation of transmission electron microscopy (TEM) confirmed the core–shell structure of FSiPUA emulsion and gave the particle size at about 50 nm. The measurement results of water contact angles and the solvent absorptions in water and n-octane for cured films showed that the water and the oil repellency for FSiPUA had been improved significantly with a suitable content of fluorine and siloxane.     

两亲8-氨基喹啉配体的合成、表征及其光谱性质

设计合成了以8-氨基喹啉为亲水头基的两亲配体：2-十六烷基丙二酸二(8-氨基喹啉)酰胺(H2A)。通过元素分析、红外光谱、核磁共振、荧光和UV-Vis光谱表征鉴定了这个化合物。在UV-Vis光谱中，H2A的吸收峰随溶剂极性的增大而紫移，F(n，ε)函数(ε为溶剂的介电常数，n为折射率)对H2A吸收带频率具有线性关系。H2A在室温、中性条件下具有荧光现象，Zn^2 离子使H2A的荧光强度稍有增加，而Cu^2 离子对H2A的荧光具有强的淬灭作用。H2A及其LB膜可被用作电致发光器件的发光层。     

中国石化成品油二次物流配送优化系统的建设与实施效果

介绍了中国石化成品油二次物流配送优化系统的开发、建设过程以及实施效果,提出了进一步提升该系统的建议.     

大量Li+存在的卤水体系中容量法测定Ca2+的分析方法研究

在Li 、Ca2 共存的相化学研究中,大量Li 的存在对配位滴定法测定Ca2 易产生较大干扰,致使卤水体系中钙的测定结果产生较大偏离。本文在进一步研究了用三乙醇胺作掩蔽剂消除Li 干扰的实验基础上,对高锂钙比(mLi∶mCa≥5)消除Li 的干扰,首次发现正丁醇-无水乙醇的混合液可有效掩蔽共存Li 的干扰。实验结果表明,该方法可使Ca2 分析结果相对误差不超过0.3%。样品加标回收率为99.90%~100.09%,相对标准偏差<0.2%。     

三元乙丙橡胶－甲基丙烯酸甲酯溶胀机械接枝共聚研究

采用直接溶胀法，在叶片混合器中以不同条件制备了三元乙丙橡胶－甲基丙烯酸甲酯接枝共聚物。通过动态力学粘弹谱表征，该接枝共聚物具有稳定的双相体系相态。在适宜条件下，可以制得较好综合性能的接枝共聚物。     

青藏铁路新增西宁至格尔木二线冬期混凝土施工技术与混凝土冻融试验研究

总结了青藏铁路新增西格二线的冬期混凝土施工技术,并进行了大量冻融试验研究.     

从"特富龙事件"再议绿色化学在高等教育中的重要性

高等院校是国家培养人才的重要场所,为保证新世纪我国经济的可持续发展,本文就"特富龙事件"分析了在高等教育中实施绿色化学教育的必要性,并提出了实施绿色化学教育的具体建议.     

Surface morphology and nodule formation mechanism of cellulose acetate membranes by atomic force microscopy

By the use of atomic force microscopy (AFM), formation mechanism of nodular structure in cellulose acetate membranes was systematically investigated. Elementary factors affecting the nodule formation were delineated on the basis of both kinetic and thermodynamic considerations. It was shown that (1) the exact nature of nodular structure is thermodynamic equilibrium glassy state; nodular structure will vanish in the rubbery state; (2) the thermodynamic factor affecting nodule formation is the membrane formation temperature; with the membrane formation temperature decreasing, more chain segments are able to form nodular structures; (3) nodule formation is dependent on the segment rearrangement; variation of the solvent environment is the major kinetic factor affecting the segment rearrangement and nodule formation. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 1328–1335, 2003     

八羰基二钴的合成

本文考察了反应起始原料、催化剂及其加入量、溶剂和压力对八羰基二钴合成的影响，得出了最佳的合成条件．