Study on the dispersion characteristic of the plasma-loaded relativistic BWO

The dispersion characteristic of the plasma-loaded relativistic backward wave oscillator has been analyzed. The theoretical model has been established and the numerical calculations accord with the experimental results, which provides some useful suggestions on the designing of slow-wave structure of BWO.     

Epoxy resin containing polyphenylsilsesquioxane: Preparation,morphology, and thermomechanical properties

Polyphenylsilsesquioxane (PPSQ) was incorporated into an epoxy resin to prepare organic–inorganic composites, and two strategies were adopted to afford composites with different morphologies. Phase separation induced by polymerization occurred in the physical blending system. However, nanostructured composites were obtained when a catalytic amount of aluminum triacetylacetonate was added to mediate the reaction between PPSQ and diglycidyl ether of bisphenol A (DGEBA). The intercomponent reaction significantly suppressed the phase separation on the micrometer scale. Organic–inorganic composites with different morphologies displayed quite different thermomechanical properties. Both differential scanning calorimetry and dynamic mechanical analysis showed that the nanostructured composites possessed higher glass‐transition temperatures than the phase‐separated composites with the same loading of PPSQ, although the intercomponent reaction between PPSQ and DGEBA reduced the crosslinking density of the epoxy matrix. This result was ascribed to the presence of nanosized PPSQ domains in the nanostructured composites, which acted as physical crosslinking sites and thus reinforced the epoxy networks. The nanoreinforcement of the PPSQ domains afforded the enhanced dynamic storage modulus for the nanostructured composites in comparison with the phase‐separated composites with a PPSQ concentration less than 15 wt %. In terms of thermogravimetric analysis, the organic–inorganic composites displayed improved thermal stability and flame retardancy. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 1093–1105, 2006     

Superposition-model investigations of the zero-field splittings and their stress and temperature dependence for Mn in guanidinium aluminum sulfate hexahydrate

The zero-field splittings of sites I and II for Mn²⁺ in guanidinium aluminum sulfate hexahydrate (GASH) are calculated from the superposition model by using the normal intrinsic parameter ₂(R₀) obtained from Mn²⁺ ions in many oxygen octahedra. The results are in good agreement with the experimental findings. Based on this, the local compressibilities and local thermal expansion coefficients in the vicinity of the impurity ion Mn²⁺ have been studied from the stress and temperature dependence of zero-field splitting and are found to be half of the host ones. The reasonableness of these local values is discussed.     

钢卷尺刻度在线测量系

本文介绍了一种钢卷尺刻度在线测量系统 ,它采用了高速摄像及计算机数据处理技术 ,文章阐述了系统的非接触动态测量原理 ,描述了光电信号的处理方法 .     

单层光学薄膜中薄膜－衬底体系的双重干涉效应及其应用

提出了单层光学薄膜中薄膜与衬底反射光之间的双重干涉效应的理论，实验结果证实了理论分析的正确性。双重干涉效应使薄膜－衬底体系的热致反射调制度高达８０％，这一效应可望有极广泛的应用     

Ti－Si沸石的催化氧化性能Ⅱ．环己醇的氧化及环己酮的肟化

Ｔｉ－Ｓｉ沸石的催化氧化性能Ⅱ．环己醇的氧化及环己酮的肟化夏清华，王公慰，应慕良，郑禄彬（中国科学院大连化学物理研究所，大连１１６０１２）关键词Ｔｉ－Ｓｉ沸石催化剂，Ｈ_２Ｏ_２氧化剂，环己醇氧化，环己酮肟化．１．前言环己酮肟是生产ε－己内酰胺的关键中...     

含羧基聚有机硅氧烷—PEO复合物与LiCF3SO3复合膜的离子传导性

本文研究了含羧基聚有机硅氧烷——PEO复合物与LiCF_3SO_3复合膜的离子传导性能。实验结果表明,利用PEO与含羧基聚有机硅氧烷复合的方法能进一步提高含羧基聚有机硅氧烷—Li~+固体电解质膜的离子传导性。此复合膜在室温下的离子导电率可达10~(-5)S cm~(-1)。本文还研究了复合膜中所用PEO的分子量、PEO用量,LiCF_3SO_3含量、交联剂用量及温度对复合膜离子传导性的影响。