新法制备高亮度蓝色SrS∶Ce薄膜电致发光器件

以ＳｒＳ∶Ｃｅ和ＺｎＳ的混晶为原料用电子束蒸发的方法制备了蓝色ＳｒＳ∶Ｃｅ薄膜电致发光（ＴＦＥＬ）器件,研究了新法制备的ＳｒＳ∶Ｃｅ膜的光致发光（ＰＬ）性能和它的电致发光（ＥＬ）器件的电致发光性能,并与直接用ＳｒＳ∶Ｃｅ粉末制备的薄膜和器材的性能进行了对比．结果表明混晶法制备的薄膜电致发光器件的亮度和效率比直接法制备的器件要高得多,且ＺｎＳ的引入弥补了在ＳｒＳ∶Ｃｅ薄膜Ｓ的不足,避免了直接用ＳｒＳ∶Ｃｅ材料蒸发而采用的共Ｓ蒸发方法中Ｓ气氛对环境的污染．     

聚合物基ZnO纳米线的制备和生长机理研究

采用独特的高分子溶液自组装生长方法, 在经化学镀预处理的基底上利用高分子溶液的网络络合效应制备了ZnO纳米线. 通过场发射扫描电子显微镜(FE-SEM), X射线能谱仪(EDS)等对样品的表面形貌及组成进行了观测表征. 结果显示, 纳米线直径约50 nm, 长度达到了数微米; 产物Zn、O化学计量比接近1∶1. 通过Si基底经化学镀工艺预处理和未经化学镀预处理对ZnO纳米结构、紫外吸收和PL性能影响的分析比较, 发现了化学镀Ni对于纳米线长度和直径尺寸的控制更为有效; 在PL图谱中, 经化学镀预处理的样品在中心波长385 nm出现了由激子碰撞复合所形成的近紫外发光峰. 进一步还分析了在不同的pH值和反应时间下样品的紫外吸收和光致发光性能. 通过以上实验, 讨论并提出了ZnO纳米线的生长机理及过程, 认为纳米线的生长是在化学镀催化剂和高分子双重作用下进行的.     

Oracle数据库系统中PL/SQL程序的自动生成

介绍了Ｏｒａｃｌｅ数据库系统中含ＳＥＬＥＣＴ、ＩＮＳＥＲＴ、ＵＰＤＡＴＥ和ＤＥＬＥＴＥ语句的ＰＬ／ＳＱＬ程序自动生成工具的设计与实现。分析了ＳＱＬ中ＳＥＬＥＣＴ、ＩＮＳＥＲＴ、ＵＰＤＡＴＥ和ＤＥＬＥＴＥ语句的语法结构，介绍了Ｏｒａｃｌｅ数据库中系统表ＵＳＥＲ－ＴＡＢ－ＣＯＬＵＭＮＳ的内容和结构，最后介绍了采用三遍扫描的方法实现ＰＬ／ＳＱＬ程序自动生成的过程。     

用UNIXLEX／YACC生成PL／0编译器

给出利用ＵＮＩＸ系统的语言开发工具ＬＥＸ和ＹＡＣＣ生成把ＰＬ／０语言源程序翻译成８０８８汇编程序的编译器的原理和方法，并给出一个编译实例．     

激光辐照和高温氧化硅锗合金的低维结构和发光特性

采用强激光辐照硅锗合金,然后高温氧化的方法,在样品表面生成微米级小孔,用高精度扫描电镜观察孔内结构,发现片状纳米结构的存在。用荧光光谱仪测量其光致荧光谱,对于激光辐照(无高温氧化)的样品,在峰值705 nm处出现较强的光致发光(PL)。高温氧化后,样品在606 nm处出现一尖锐的PL光谱。利用量子受限和纳晶与氧化物的界面态综合模型解释PL光谱的产生。     

Facile ion-exchange synthesis of Gd-doped K2Ta2O6 photocatalysts with enhanced visible light activity

One of the well-known ways of increasing the visible light absorption capability of semiconducting materials is cation doping. This study aims to use Gd doping to tailor the bandgap energy of K₂Ta₂O₆ (KTO) for photocatalytic degradation of organic pollutants under visible light irradiation. Accordingly, the parent KTO and Gd-doped KTO with different Gd concentrations (K_2-3xGd_xTa₂O₆; x = 0.025, 0.05, 0.075 and 0.1 mol%) were synthesized by hydrothermal and facile ion-exchange methods, respectively. The powder XRD, FT-IR, SEM-EDS, TEM-SAED, N₂ adsorption-desorption, XPS, UV–Vis DRS, PL and ESR techniques were used to investigate the effect of Gd dopant concentration on the structural and photocatalytic properties of KTO. The photocatalytic activity of these samples was investigated for the photocatalytic degradation of methylene blue (MB) dye in an aqueous solution at room temperature under visible light irradiation. The experimental results show that all Gd-doped KTO samples exhibit enhanced photocatalytic activity compared with parent KTO toward MB degradation. In particular, Gd-KTO obtained by doping of 0.075 mol% shows the highest photocatalytic activity among the Gd-doped samples and the degradation efficiency of MB was 79% after 180 min of visible light irradiation, which is approximately 1.5 times as high as that by parent KTO (53%). In addition, trapping experiments and electron spin resonance (ESR) analysis demonstrated that the hydroxyl radicals (^?OH) have played a crucial role in the photocatalytic degradation of MB. The reusability and stability of Gd doped-KTO with a Gd content of 0.075 mol% against MB degradation were examined for five cycles. Based on the present study results, a visible light induced photocatalytic mechanism has been proposed for Gd0075-KTO sample.     

Characteristic material parameters of CIGS solar cell related with device performance

CIGS solar cells with power conversion efficiency (PCE) in the range of 1.82%–12.30% were obtained by using two-step process, and were further analyzed through various measurement techniques. Material parameters showed diverse values and some trends depending on the device performance. The lower performance device showed small integrated PL intensity, short minority life time, larger defect density and lower activation energy, whereas the higher performance device showed opposite values. We investigated relationship between material parameters and PCE of solar cells, and found that some physical parameters such as integrated PL intensity, minority life time, defect density, and difference between band gap and activation energy (E_g-E_a), which all reflect defect states in bulk and at pn interface, are strongly related with PCE and would be used as a good indicator to evaluate device performance quickly.     

声表面波器件用〈110〉取向ZnO薄膜的MOCVD生长

Zn O是具有纤锌矿晶体结构的多功能半导体材料 ,它具有 3 .3 7e V的禁带宽度和高达 60 me V的激子束缚能 ,是很有希望的紫外发光材料 .由于具有 c轴的择优取向性 ,因此目前人们的注意力主要集中在对 c轴取向 Zn O薄膜的特性研究上 [1～ 3] .但其它取向的 Zn O薄膜也可在某些衬底的特定面上 ,通过特定的条件进行生长 ,如〈1 1 0〉取向的 Zn O薄膜可在特定的条件下生长在蓝宝石 R面衬底上[4～ 7] .由于 (1 1 0 )面的 Zn O薄膜具有一些 c轴取向薄膜所不具备或无法比拟的特性 ,如 :机电耦合系数高达6% (C面薄膜的机电耦合系数却不足 1 % )…     

Beyond labels: A review of the application of quantum dots as integrated components of assays, bioprobes, and biosensors utilizing optical transduction

A comprehensive review of the development of assays, bioprobes, and biosensors using quantum dots (QDs) as integrated components is presented. In contrast to a QD that is selectively introduced as a label, an integrated QD is one that is present in a system throughout a bioanalysis, and simultaneously has a role in transduction and as a scaffold for biorecognition. Through a diverse array of coatings and bioconjugation strategies, it is possible to use QDs as a scaffold for biorecognition events. The modulation of QD luminescence provides the opportunity for the transduction of these events via fluorescence resonance energy transfer (FRET), bioluminescence resonance energy transfer (BRET), charge transfer quenching, and electrochemiluminescence (ECL). An overview of the basic concepts and principles underlying the use of QDs with each of these transduction methods is provided, along with many examples of their application in biological sensing. The latter include: the detection of small molecules using enzyme-linked methods, or using aptamers as affinity probes; the detection of proteins via immunoassays or aptamers; nucleic acid hybridization assays; and assays for protease or nuclease activity. Strategies for multiplexed detection are highlighted among these examples. Although the majority of developments to date have been in vitro, QD-based methods for ex vivo biological sensing are emerging. Some special attention is given to the development of solid-phase assays, which offer certain advantages over their solution-phase counterparts.     

资源整合下广西北部湾港第四方物流集成模式探析

从第四方物流资源整合的角度,结合广西北部湾港的实际情况,构建了北部湾港第四方物流集成运作模式,并就模式运作的挑战和应对策略做了详细阐述。