金属有机化学气相沉积法制备钛酸铅铁电薄膜

利用低压ＭＯＣＶＤ工艺分别在（００１）取向的ＬａＡｌＯ_３，ＳｒＴｉＯ_３和重掺杂硅单晶衬底上制备ＰｂＴｉＯ_３铁电薄膜，并通过Ｘ射线衍射谱对薄膜的微结构进行分析．Ｘ射线θ－２θ扫描显示硅衬底上得到了ＰｂＴｉＯ_３多晶薄膜，另两种衬底上得到了择优取向的ＰｂＴｉＯ_３薄膜．ＬａＡｌＯ_３衬底上的ＰｂＴｉＯ_３薄膜有ａ和ｃ两个取向，也就是薄膜中存在着９０°畴结构，而生长在ＳｒＴｉＯ_３衬底上的ＰｂＴｉＯ_３薄膜中只存在ｃ方向的择优取向．由于薄膜的尺度效应，发现ｃ轴晶格常数与块材相比均缩短．Ｘ射线的φ扫描验证了后两类薄膜的外延特性，利用同步辐射的高强度和高能量分辨率用摇摆曲线方法研究了这两种外延薄膜的品质，进一步证明了ＳｒＴｉＯ_３衬底上的ＰｂＴｉＯ_３薄膜的单畴特性．利用重掺杂的硅衬底作底电极，测量显示直接生长于硅衬底上的ＰｂＴｉＯ_３多晶薄膜具有良好的铁电性能 关键词：     

Reflection of Surface Plasmon Polaritons by a Corner Reflector of Negative Index Materials

A novel type of corner reflector for the reflection of surface plasmon polariton (SPP) is proposed. The reflector consists of two layers of compensatory media whose permittivity and permeability take opposite signs to that of the corresponding layer of the SP waveguide. By rigorously solving Maxwell's equations, the reflected SPP is proved to exist. The transverse wave vector of the reflected SPP is always antiparallel to that of the incident SPP and no phase retardation is introduced.     

Interfacial structure and electrical properties of LaAlO3 gate dielectric films on Si by metalorganic chemical vapor deposition

LaAlO₃ (LAO) gate dielectric films were deposited on Si substrates by low-pressure metalorganic chemical vapor deposition. The interfacial structure and composition distribution were investigated by high-resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS), secondary-ion mass spectroscopy (SIMS), and Auger-electron spectroscopy (AES). HRTEM confirms that there exists an interfacial layer between LAO and Si in most samples. AES, SIMS, and XPS analyses indicate that the interfacial layer is compositionally graded La–Al silicate and the Al element is severely deficient close to the Si surface. Electrical properties of LAO films were evaluated. No evident difference in electrical properties between samples with and without native SiO₂ layers was observed. The electrical properties are discussed in terms of LAO growth mechanisms, in relation to the interfacial structure. PACS 73.40.Qv; 81.15.Gh; 77.55.+f; 68.35.-p     

中物院远红外自由电子激光实验研究

中国工程物理研究院基于射频直线加速器技术的远红外自由电子激光(FIR-FEL)实验取得阶段性进展,于2005年3月24晚8时30分首次出光, 并多次重复. 中心波长115μm, 谱宽1%.介绍了实验系统的主要组成部分和主要实验结果.     

新型噻吩基取代卟啉的合成及其荧光光谱研究

合成了两种新型噻吩基卟啉－5，15－二（2－噻吩基）－2，8，12，18－四乙基－3，7，13，17－四甲基卟啉7a（45．1％）和5，15－二（2－联噻吩基）－2，8，12，18－四乙基－3，7，13，17－四甲基卟啉7b(61.2%),并研究了它们的光谱性质，其中荧光光谱的最大发射峰蜂都在631nm处，量子产率分别为4．1％（7a)和1．4％（7b)。     

Isothermal crystallization kinetics of poly(3‐hydroxybutyrate)/layered double hydroxide nanocomposites

Poly(3‐hydroxybutyrate) (PHB)/layered double hydroxides (LDHs) nanocomposites were prepared by mixing PHB and poly(ethylene glycol) phosphonates (PEOPAs)‐modified LDH (PMLDH) in chloroform solution. Both X‐ray diffraction data and TEM micrographs of PHB/PMLDH nanocomposites indicate that the PMLDHs are randomly dispersed and exfoliated into the PHB matrix. In this study, the effect of PMLDH on the isothermal crystallization behavior of PHB was investigated using a differential scanning calorimeter (DSC) and polarized optical microscopy. Isothermal crystallization results of PHB/PMLDH nanocomposites show that the addition of 2 wt % PMLDH into PHB induced more heterogeneous nucleation in the crystallization significantly increasing the crystallization rate and reducing their activation energy. By adding more PMLDH into the PHB probably causes more steric hindrance of the diffusion of PHB, reducing the transportation ability of polymer chains during crystallization, thus increasing the activation energy. The correlation among crystallization kinetics, melting behavior and crystalline structure of PHB/PMLDH nanocomposites can also be discussed. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 3337–3347, 2006     

Synthesis of a Novel Aromatic Diamino-bridged Bis（β-cyclodextrin） and its Inclusion Complexation with Dyes Molecules

Bridged bis(β-cyclodextrin)s (CDs), as a very important family of CD derivatives, have been known that they can significantly alter the molecular binding ability and selectivity toward a variety of guests in comparison with parent cyclodextrin. Their two…     

Paper-like Microfibrous Nickel Catalyst for Hydrogen Production via NH3 Decomposition in Fuel Cell Applications

Recently, miniature H2 generator to power fuel cells for portable/micro electronic devices and passenger propulsion has been the focus of intense research activities1-3. One of the strategies is to find simple CO-free H2 production with novel microreactor…