基于面式-三(2-(4-三氟甲基苯基)吡啶)合铱配合物为发光中心的高效绿光有机电致发光器件

用经典的方法合成了面式-三(2-(4-三氟甲基苯基)吡啶)合铱配合物(fac-Ir(tfmppy)₃), 并得到了其晶体结构。在CH₂Cl₂溶液中Ir(tfmppy)₃的发射光谱显示出了峰值位于525 nm的π→π^*跃迁吸收以及金属到配体电荷转移(MLCT)吸收, 色坐标(CIE)为(0.31, 0.62), 量子效率计算为4.59%(以Ru(bpy)₃]Cl₂为参照)。以Ir(tfmppy)₃为发光中心, 制备并研究了有机电致发光器件:ITO/TAPC (60 nm)/Ir(tfmppy)₃ (x%):mCP (30 nm)/TPBi (60 nm)/LiF (1 nm)/Al (100 nm)。4%掺杂浓度的器件在4 197 cd·m^-2的亮度下显示的最大电流效率为33.95 cd·A^-1, 在12.7 V时的最大亮度为43 612 cd·m^-2, 色坐标(CIE)为(0.31, 0.61)。利用瞬态电致发光法(transient electroluminescence (EL))、在1 300 (V·cm^-1)^1/2的电场强度下Ir(tfmppy)₃配合物的电子迁移率测定为4.24×10^-6 cm²·(V·s)^-1。非常接近于常用的电子传输材料八羟基喹啉铝(Alq₃)的电子迁移率。     

荧光素衍生物在TiO_2胶体中的光物理性质研究

测定了以荧光素为光敏剂的电子给体-受体二元化合物荧光素蒽醌甲酯（FL- AQ）及模型化合物荧光素丁酯（FL4）在溶液中和在二氧化钛（TiO_2）胶体中的吸 收光谱、荧光光谱、荧光寿命等。发现荧光素蒽醌甲酯与荧光素丁酯均可通过酚羟 基较好地吸附在TiO_2胶体上。从吸收光谱可得,FL4与TiO_2形成表面络合物的表 观结合常数（K_(app)）大约为3590 mol~(-1)·L,结合率（α）为0.86;FL-AQ与 TiO_2形成表面络合物的K_(app)大约为3060 mol~(-1)·L,α为0.84。同时通过 ESR光谱讨论了光诱导电子注入机制。     

Synthesis and optical properties of metal-centered dimeric fullerene macromolecules

Dimeric fullerene macromolecules were prepared via the complexation of two fullerenylated 2,2′:6′,2″-terpyridine ligands with Fe(II) and Co(II) ions. The solubility of these macromolecules in some organic solvents allowed both their structural characterization and a study of their optical properties. The electronic absorption and emission of the macromolecules in solution were evaluated; and the results indicated no meaningful ground-state and excited singlet state intramolecular charge transfer interactions. However, the laser flash photolysis results could be explained in terms of the electron transfer quenching of the excited triplet methanofullerene moiety by the center metal–ligand complex in the macromolecules. The optical limiting properties of the macromolecules in solution were also investigated in comparison with those of the ligands for an evaluation of the complexation effects.     

Kinetics and mechanism of electron-induced splitting of a cyclobutane pyrimidine dimer with or without an electron acceptor

DNA repair has received heightened attention in recent years as ozone depletion threatens to significantly increase DNA damage by UVB radiation[1—6]. The major lesions formed in DNA by this radiation are cis-syn cyclobutane pyrimidine dimers, which are created by the linkage of two neighboring pyrimidine bases in DNA via C5-C5 and C6-C6 atoms by [2+2] cycloaddition[2,5—8]. This potentially lethal or mutagenic damage can be repaired either by the removal of the damaged bases by excisio…     

Study of the electronic and atomic structure of thermally treated SrTiO3(110) surfaces

The electronic structure of heated SrTiO₃(110) surfaces was investigated with metastable impact electron spectroscopy and ultraviolet photoelectron spectroscopy (He(I)). Scanning tunnelling microscopy and atomic force microscopy (AFM) were used to study the topology of the surface. The crystals were heated up to 1000°C under reducing conditions in ultrahigh vacuum or under oxidizing conditions in synthetic air for 1 h, respectively. Under both conditions microfacetting of the surface is observed. The experimental results are compared with ab initio Hartree–Fock calculations, also presented here, carried out for both ideal and reconstructed SrTiO₃(110) surfaces. The results give direct evidence for Ti termination of the faceted TiO₂ rows. Copyright © 2003 John Wiley & Sons, Ltd.     

CaS：Ce，Sm的制备及性能表征

采用碳还原法制备了CaS：Ce，Sm样品，并研究了反应机理、还原原理以及灼烧温度对CaS晶格形成和光激励发光的影响。样品的XRD测试表明，采用碳还原法制备的CaS：Ce，Sm样品，具有纯CaS的面心立方结构，晶格常数a=0.569 4 nm，样品的激发光谱是峰值分别位于295 nm和461 nm的宽带谱，样品的荧光光谱是峰值位于503 nm、560 nm、600 nm和655 nm带谱，光激励发光光谱是峰值分别位于500 nm，565 nm和605 nm的宽带谱，光激励激发光谱是峰值位于1 150 nm的宽带谱。     

减压化学气相沉积法制备规则螺旋状纳米碳管

以硅胶负载的Co纳米颗粒为催化剂,在低流量的减压体系中通过化学气相沉积法制备了规则螺旋状的纳米碳管.通过TEM和HRTEM研究了螺旋碳管的形貌、尺度分布以及管身、曲面和节点处的晶型;讨论了催化剂制备中pH值对催化剂的尺寸、规则程度和存在形态以致对螺旋碳管产量、管径厚度以及螺旋管的相对比例的影响;此外,还分析了反应压力对碳管生长的影响.     

Summary of ISO/TC 201 standard: XXI. ISO 21270:2004—Surface chemical analysis—X‐ray photoelectron and Auger electron spectrometers—Linearity of intensity scale

This International Standard specifies two methods for determining the maximum count rate for an acceptable limit of divergence from linearity of the intensity scale of Auger and x‐ray photoelectron spectrometers. It also includes methods to correct for intensity non‐linearities so that a higher maximum count rate can be employed for those spectrometers for which the relevant correction equations have been shown to be valid. Copyright © 2004 John Wiley & Sons, Ltd.     

Controlled Synthesis of Sea-urchin-like ZnO Nanomaterials with the Aid of Ethylene Glycol Using a Solvothermal Method

Sea-urchin-like ZnO nanomaterials were successfully synthesized by decomposition of zinc acetate precursor in the presence of sodium hydroxide and ethylene glycol(EG) in an ethanol solution using a solvothermal method at 180 ℃ for 12 h.The crystalline phase and morphology of the resultant nanomaterials were characterized by X-ray diffraction(XRD),scanning electron microscopy(SEM),transmission electron microscopy(TEM),selected-area electronic diffraction(SAED) and high-resolution electron microscopy(HRTEM).Interestingly,the sizes and prod length of the samples can be easily tuned by changing the amount of directing agent EG and keeping other reaction conditions unchangeable.On the basis of our experimental outcomes,EG-controlled-nucleation-growth formation mechanism was proposed to correspond for the sea-urchin-like ZnO growth processes.And the photoluminescence(PL) spectra of the as-selected samples were measured at room temperature,presenting two emission peaks centered at～388 and 480 nm.     

环双(百草枯对苯撑)-双2-萘甲酸三缩四乙二醇酯二元超分子给受体体系光诱导电子转移研究

本文利用核磁氢谱、吸收光谱和荧光光谱证明了环双(百草枯对苯撑)(CBPQT)与双2-萘甲酸三缩四乙二醇(N-P₄-N)在乙腈溶液中能够形成1:1的二元超分子给受体体系.瞬态吸收光谱的研究表明该超分子体系中光诱导电子转移的速率k_CS>1.0×10⁸s^-1,电子回传的速率k_CR=1.26×10³s^-1,光诱导电子转移所生成电荷分离态的寿命长达794μs.