Structural Description of Polyaromatic Nucleus in Residue

The proton nuclear magnetic resonance spectroscopy （1H-NMR）, the synchronous fluorescence spectrometry （SFS） and the ruthenium ions catalyzed oxidation （RICO） method were used to determine the chemical structure of polyaromatic nucleus in Oman residue fractions. The results of 1H-NMR analyses showed that the average numbers of aromatic rings in the aromatics, resins and asphaltenes units were 3.2, 5.6 and 8.2, respectively. SFS was used to investigate the distribution of aromatic rings in residue fractions, the main distribution range of aromatic rings in aromatics, resins and asphaltenes were 3 4 rings, 3--5 rings and more than 5 rings, respectively. The aromatic network in residue fractions was oxidized to produce numerous carboxylic acids. The types and content of benzenepolycarboxylic acids, such as phthalic acid, benzenetricarboxylic acids, benzenetetracarboxylic acids, benzenepentacarboxylic acid and benzenehexacarboxylic acid disclosed the condensed types of aromatic nuclei in the core. The biphenyl fraction （BIPH）, the cata-condensed fraction （CATA）, the peri-condensed fraction （PERI） and the condensed index （BCI） were calculated based on the benzenepolycarboxylic acids formed. The results implied that there was less biphenyl type structures in all residue fractions. The aromatics fraction was almost composed of the cata-condensed type system, and the asphaltenes fraction was wholly composed of the peri-condensed type system, while in the resins fraction co-existed the two types, herein the peri-con- densed type was predominant over the cata-condensed type. Based on the analytical results obtained in the study, the components --aromatics, resins and asphaltenes -- were given the likely structural models.     

SiCf/SiC陶瓷复合材料的研究进展

SiCf/SiC陶瓷复合材料具有良好的力学性能、高温抗氧化性和化学稳定性，是航空航天和原子能等领域理想的新一代高温结构材料。本文概述了增强体SiCt的发展状况及存在的问题，对SiCt/SiC材料的制备工艺、界面相的研究状态、材料的损伤破坏机理和目前的应用研究进展做了综述，并分析了SiCf/SiC陶瓷复合材料的研究重点和发展前景。     

固体中光声拉曼效应的理论分析

从非线性波动方程出发，运用准平衡模型以及热弹理论，对固体样品中光声拉曼效应进行理论分析，导出了脉冲激光泵浦下光声拉曼信号的解析表达式，并总结分析了固体中光声拉曼效应的一些原理特性、实验问题和应用价值。     

Conduction band states of transition metal (TM) high-k gate dielectrics as determined from X-ray absorption spectra

This paper uses X-ray absorption spectroscopy to study the electronic structure of the high-k gate dielectrics including TM and RE oxides. The results are applicable to TM and rare earth (RE) silicate and aluminate alloys, as well as complex oxides comprised of mixed TM/TM and TM/RE oxides. These studies identify the nature of the lowest conduction band d^* states, which define the optical band gap, E_g, and the conduction band offset energy with respect to crystalline Si, E_B. E_g and E_B scale with the atomic properties of the TM and RE atoms providing important insights for identification high-k dielectrics that meet performance targets for advanced CMOS devices.     

星间激光通信技术进展与趋势

较详细地评述了目前国外卫星间光通信技术研究的现状．根据关键单元技术的进展情况，总结了未来星间光通信系统的发展趋势。     

Preparation of Pb(Zr0.52Ti484848)O3 thin films on silicon-on-insulator substrates by excimer laser deposition combined with rapid thermal annealing

In this paper we report the fabrication of ferroelectric Pb(Zr_0.52Ti_0.48)O₃ (PZT) thin films on Si-on-Insulator (SOI) substrates with and without an electrode by pulsed excimer laser deposition combined with rapid thermal annealing. Based on the structural and interfacial characteristics analysis by X-ray diffraction (XRD), Rutherford backscattering spectroscopy (RBS), cross-sectional transmission electron microscopy (XTEM) and automatic spreading resistance measurement (ASR), the film structure and orientation were revealed to be dependent on the annealing time and annealing temperature as well as deposition temperature. From RBS spectra and XTEM observation it is shown that the PZT thin films did not interact with the top silicon layers of SOI and that the composition of the film was similar to the target. The ASR measurements showed that the electrical properties of PZT/SOI as well as PZT/Pt/SOI were abrupt, and that the electrical properties of the SOI substrates were still good after the PZT growth.     

初论带状光纤缆结构设计

推导出了成叠带状光纤在松套管中余长的两个计算公式，此两公式是带状光纤缆结构设计需要用到的基本公式。此外，还对带状光纤缆结构设计作了初步讨论。     

双臂协调约束系统动力学问题探讨

本文讨论了双臂协调约束系统的动力学问题．文中系统地描述了该系统的适应于计算机程序化的建模方法；推导了系统的动力学方程，并给出了用约束矩阵的正交补矩阵处理系统所受协调约束的方法；编制了相应的计算机辅助分析程序ＤＲＣＲＣＳ，并用该程序对算例进行了动力学的数值分析。     

Normal form approach to compiler design

This paper demonstrates how reduction to normal form can help in the design of a correct compiler for Dijkstra's guarded command language. The compilation strategy is to transform a source program, by a series of algebraic manipulations, into a normal form that describes the behaviour of a stored-program computer. Each transformation eliminates high-level language constructs in favour of lower-level constructs. The correctness of the compiler follows from the correctness of each of the algebraic transformations.