Laser-induced changes on the complex refractive indices of phase-change thin film

The refractive indices of crystalline phase-change films are usually obtained by thermal-induced crystallization. However, this is not accurate, because the crystallization of phase-change film in rewritable optical disks is laser induced. In this study, we use the initializer to crystallize the phase-change films. The dependence of the refractive index n and the extinction coefficient k of the phase-change films on the initialization conditions are studied. Remarkable changes of the refractive indices (especially k) are found when the initialization laser power density is 6.63 mW/mum(2) and the initialization velocity is 4.0 m/s. At the same time, the structure changes of the phase-change films are also studied. This dependence is explained by the structure change of the films. These results are significant in improving the accuracy of optical design and the thermal simulation of phase-change optical disks, as well as in the study of phase-change optical disks at shorter wavelengths. (C) 2003 Society of Photo-Optical Instrumentation Engineers.

Investigations on valence-change behaviors of europium ions in Eu-doped aluminate and silicate phosphors

Compounds of Sr3Al2O6: Eu, Sr4Al14O25: Eu, and BaZnSiO4: Eu were synthesized by high-temperature solid state reactions. The doping Eu3+ ions were partially reduced to Eu2+ in Sr4Al14O25: Eu and BaZnSiO4: Eu prepared in an oxidizing atmosphere, N-2 + O-2. However, such an abnormal reduction process could not be performed in Sr3Al2O6: Eu, which was also prepared in an atmosphere of N-2 + O-2. Moreover, even though Sr3Al2O6: Eu was synthesized in a reducing condition CO, only part of the Eu3+ ions was reduced to Eu2+. The existence of trivalent and divalent europium ions was confirmed by photoluminescent spectra. The different valence-change behaviors of europium ions in the hosts were attributed to the difference in host crystal structures. The higher the crystal structure stiffness, the easier the reduction process from Eu3+ to Eu2+.

黄芪复合体Astragalus penduliflorus Lam. complex (Leguminosae)的物种生物学研究

本文对黄芪复合体（Astragalus penduliflorus）复合体进行了物种生物学研究，主要内容包括如下： 1、形态学与物种生物学证据支持目前承认的黄芪复合体5种4变种应分为1种5亚种（其中新亚种一个）。它们是A. penduliflorus subsp. penduliflorus, A. penduliflorus subsp. seiceocanus, A. penduliflorus subsp. mongholicus, A. penduliflorus subsp. qinhaiensis（新亚种）和A. penduliflorus subsp. pallidipurpureus等5个分类实体。 2、讨论了分类群间的形态演化关系。黄芪复合体的进化趋势可能为：A. penduliflorus subsp. pallidipurpurous A. penduliflorus subsp. Qinhaiensis → A. penduliflorus subsp. Mongholius → A. penduliflorus subsp. Sericeocanus → A. penduliflorus subsp. pendulifloras。 3、分析了黄芪复合体3个亚种10个居群的染色体核型，它们的染色体2n=16，各居群间的核型呈现连续的变异式样。 4、分析了黄芪复合体5个亚种13个居群和两个近缘种的种子蛋白，并进行了聚类分析，认为种子蛋白性状在黄芪复合体的居群内比较稳定，且同一居群内的不同个体间无明显差异。同时，种子蛋白分析说明了复合体内居群也呈现连续变异。 5、应用最大同步分支分类法及最小平行进化分支分类法分析了黄芪复合体的谱系分支发生，确认复黄芪复合体为一自然复合种是比较客观的。

The association of the Arabidopsis actin-related protein (ARP) 2/3 complex with cell membranes is linked to its assembly status but not its activation

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