Multifractal Formalism for Almost all Self-Affine Measures

We conduct the multifractal analysis of self-affine measures for “almost all” family of affine maps. Besides partially extending Falconer’s formula of L ^q -spectrum outside the range 1 < q ≤ 2, the multifractal formalism is also partially verified.     

齐次Moran集的维数

设μ(|n_k|_k≥1,|c_k|_k≥1)为正整数序列|n_k|_k≥1与正数序列|c_k|_k≥1确定的齐次Moran集的集类.确定了μ中元素的Hausdorff维数的最大值与最小值,并证明对任一介于上述最大值和最小值之间的数s,存在μ中的元素,其Hausdorff维数等于s,前述结论对于填充维数亦成立。还讨论了齐次Moran集的其他性质。     

光学微盘腔与三能级量子点系统中的模耦合研究

用一种全量子理论方法研究了波导、光学微盘腔与三能级量子点耦合系统的动力学过程,求出其耦合后的透射模和反射模的解析解. 由于微腔表面粗糙引起反向散射,在微腔内形成两简并回音壁耦合共振模,其耦合率为β;量子点的两激发态分别以耦合率g₁,g₂与回音壁耦合共振模产生耦合. 在实数空间里,得出透射光谱和反射光谱的数值解,这些三能级模型结果比二能级模型结果更接近真实光学微盘腔系统,能更好地显示耦合系统的动力学特性. 关键词： 模耦合 光学微盘腔 三能级量子点 全量子理论     

Magnetic Properties and Magnetoresistance of CdMnS：Au Based Structures Prepared by Co-evaporation

Polycrystalline CdMnS and CdMnS：Au films with hexagonal structure on Si（111） substrates are prepared by co-evaporation, and exhibit ferroelectric and ferromagnetic properties, respectively. Under optimized growth conditions, CdMnS：Au samples with an average crystallite size of 90nm and Mn concentration of 5.0at.% are obtained, and an all-semiconductor spin valve device of Co/Au/CdMnS：Au/CdMnS/Pt is fabricated. Electrical measurement of the device reveals the clear dependence of resistance on applied magnetic field, with a relative magnetoresistance of 0.06% and a switching field of 100 Oe at 77K.     

First-principles study on the geometric and electronic structures and phase transition of PbZr1-xTixO3 solid solutions

With first-principles virtual-crystal approximation calculations, we systematically investigate the geometric and elec- tronic structures as well as the phase transition of lead zirconate titanate (PbZr1-xTixO3 or PZT) as a function of Ti content for the whole range of 0 ≤ x Ti ≤ 1. It can be found that, with the increase of the Ti content, the PbZr1-xTixO3 solid solu- tions undergo a rhombohedral-to-tetragonal phase transition, which is consistent with the experimental results. In addition, we also show the evolution in geometric and electronic structures of rhombohedral and tetragonal PbZr1-x TixO3 with the increasing content of Ti.     

磺化杯芳烃修饰的金纳米粒的合成及其对多环芳烃的比色检测

通过偶联修饰的方法合成了水溶性磺化杯芳烃修饰的金纳米粒, 并研了其对多环芳烃的比色检测. 结果表明, 磺化杯芳烃修饰的金纳米粒对蒽具有良好的识别选择性. 该比色探针对蒽的检测限可达到2×10-6 mol/L. 这种比色传感器能够实现现场原位检测.     

One-pot syntheses of 2,6-diiododiaryl ethers from <Emphasis Type="Italic">para</Emphasis>-EWG-substituted phenols by diacetoxyiodobenzene

2,6-Diiododiaryl ethers are not only useful blocks to construct substituted diaryl ethers but are also characteristic drug precursors. In this research, a one-pot tandem oxidation of phenols substituted with electron-withdrawing group at the para position by excess diacetoxyiodobenzene is proven as a novel and efficient method for preparing 2,6-diiododiaryl ethers. Using this method, three new 2,6-diiododiaryl ethers, namely, methyl 3,5-diiodo-2-methoxy-4-phenoxybenzoate (2), methyl 3,5-diiodo-4-phenoxybenzoate (6), and 1-(2,6-diiodo-4-nitrophenoxy)benzene (7) were readily obtained from the corresponding phenols, and the yields were good.     

ICP-AES法测定萤石中的主次成分

萤石通过醋酸加热使ＣaＣＯ３溶解,再经过滤、沉淀、烘干,以碳酸钠、硼砂混合熔剂熔 融,酸学好以后,采用ＩＣＰ－ＡＥＳ法测定碳酸钙、氟化钙及二氧化硅、三氧化铁。此方法精密度好,回收率在９６．０％－１０１．４％之间。     

过渡金属复合氧化物电子组态与表面光伏响应的关系(Ⅰ)──M(Ⅱ)铁酸盐(M=Cu,Co,Ni)的研究

利用表面光电压谱及场诱导表面光电压谱研究了部分过渡金属复合氧化物的电子组态与其光伏响应的关系.结果表明,在过渡金属M(M＝Cu,Co,Ni)铁酸盐系列样品中,开壳层的Cu(Ⅱ)(铁酸盐)和CO(Ⅱ)(铁酸盐)的电荷转移跃迁(CT)具有双激发态的成分,其中含有较强的低能电子跃迁;与它们相比,闭壳层的Ni(Ⅱ)铁酸盐的CT跃迁则需要较大的能量.三者的FISPS证实了它们具有不同的CT跃迁性质,为其催化反应机理研究提供了微观信息.