PHOTOLUMINESCENCE STUDY OF GAAS/ALGAAS QUANTUM-WELL HETEROSTRUCTURE INTERFACES

Photoluminescence (PL) is used to study the interface properties of GaAs/AlGaAs quantum well (QW) heterostructures prepared by molecular beam epitaxy with growth interruption (GI). The discrete luminescence lines observed for the sample with GI are assigned to the splitting of the heavy-hole exciton associated with heterointerface islands with the lateral size greater than exciton diameter and mean height less than one monolayer, and the spectra have the Gaussian lineshapes. The results strongly support the microroughness model. We also study the temperature dependence of the exciton energies and find that excitons are localized at the interface roughness at low temperature even in the sample with GI. The lateral size of the microroughness of the GI sample is estimated to be less than 5 nm from the exciton localization energy.

DIFFERENT INTERDIFFUSION CHARACTERISTICS BETWEEN AG/YBA2CU3O7-X AND AL/YBA2CU3O7-X CONTACT INTERFACES

The differences between the interdiffusion characteristics of Ag/YBa2Cu3O7-x and Al/YBa2Cu3O7-x contact interfaces have been revealed by secondary ion mass spectrometry (SIMS). The different electrical properties of Ag/YBa2Cu3O7-x and YBa2Cu3O7-x films after high temperature treatment are well understood by the SIMS results.

High power red-light GaInP/AlGaInP laser diodes with nonabsorbing windows based on Zn diffusion-induced quantum well intermixing

The layer structure of GaInP/AlGaInP quantum well laser diodes (LDs) was grown on GaAs substrate using low-pressure metalorganic chemical vapor deposition (LP-MOCVD) technique. In order to improve the catastrophic optical damage (COD) level of devices, a nonabsorbing window (NAW), which was based on Zn diffusion-induced quantum well intermixing, was fabricated near the both ends of the cavities. Zn diffusions were respectively carried out at 480, 500, 520, 540, and 580 Celsius degree for 20 minutes. The largest energy blue shift of 189.1 meV was observed in the window regions at 580 Celsius degree. When the blue shift was 24.7 meV at 480 Celsius degree, the COD power for the window LD was 86.7% higher than the conventional LD.

Investigation of GaAs/AlGaAs interfaces by reflectance-difference spectroscopy

The in-plane optical anisotropy of several GaAs/AlGaAs quantum well samples with different well widths has been measured at room temperature by reflectance-difference spectroscopy (RDS). The RDS line shapes are found to be similar in all the samples examined here, which dominantly consist of two peak-like signals corresponding to 1HH-->1E and 1LH-->1E transition. As the well width is decreased, or the 1 ML InAs layer is inserted at one interface, the intensity of the anisotropy increases quickly. Our detail analysis shows that the anisotropy mainly arises from the anisotropic interface roughness. The results demonstrate that the RDS technique is sensitive to the interface structures.

基于Windows CE的HIRFL-CSR前端控制系统设计与实现

介绍了一个基于WindowsCE的嵌入式分布控制系统,系统基于以太网和现场总线连接,节点用嵌入式平板计算机实现。给出了系统的硬件组成和软件设计,该系统已应用于HIRFL-CSR前端控制系统。

在Windows下PC机作为半双工RS-485网络主机通信程序的设计

描述了一个以PC机作为半双工RS-485网络主机,工作于Windows平台上的通讯程序。该程序特点是通过使用异步通信WIN32API和多线程及多种同步量来实现半双工通信方式。

基于Windows系统的原油水气含量自动监测仪表远程控制系统的设计

本论文主要内容是一种应用于油田的工业用仪表的程序设计。程序体现了当今流行软件基本的设计思想，同时具有积极的现实意义。论文内容主要包括三大部分。第一部分简略地介绍仪表的总体的工作原理。从水含量，气含量两个方面进行了论述。第二部分介绍了仪表的工作过程中，涉及的硬件部分。简略的阐述了硬件部分的探测器结构部分，详细的介绍了第三部分软件编程中用到的计数卡和D／A转换板卡的原理，及编程控制的基本步骤。第三部分是仪表的软件部分，也是核心和重点部分。主要介绍了软件的总体框架，重点地说明了计数卡的驱动程序设计，数据采集，打印部分，数据库部分，实时性的实现方法。同时还有参数拟合功能中，涉及到的数理统计中参数回归法确定参数的具体方法。结合各个具体功能的说明，给出了具体的源代码。程序的其它必不可缺少，但实现起来难度相对较小的部分给出了简略的说明。该程序具有操作简单明了，界面友好，功能齐全等特点。通过对该工业仪表程序的设计，在计算机软件及硬件方面的理解，都能够得到一定水平的提高。特别是在计算机软件的设计方法，设计思想等各个方面都有深入的认识。

CAMAC Windows 2000驱动程序设计

兰州重离子加速器（HIRFL, Heavy Ion Research Facility at Lanzhou）是中国最大的、在国际上享有较高知名度的中、低能量重离子物理基础及其应用研究装置，HIRFL控制系统是这一大型研究装置的重要组成部分。CAMAC是HIRFL控制系统最重要的硬件接口设备，Windows 2000是HIRFL控制系统最理想的软件运行平台，所以设计一个标准的CAMAC Windows 2000驱动程序对HIRFL控制系统有着重要的意义。本文首先介绍了Windows 2000的系统总体结构以及与驱动程序编写密切相关的内核模式I/O组件。在硬件环境方面，简要叙述了CAMAC接口和EISA总线的知识。内核模式I/O处理是编写驱动程序最重要的知识，文章对此作了详细的阐述。驱动程序的各个内核模式对象是驱动程序开发的基本数据结构，是驱动程序的生命线，这部分内容在论文中占有一定的比重。在实际的驱动程序代码中，有很多类和例程，本文就几个关键的类和例程进行了剖析。最后就如何构造和安装驱动程序作了说明。作者用Microsoft Visual C++ 6.0和Windows 2000 DDK作为工具，成功地开发了CAMAC Windows 2000内核模式驱动程序并制作了最终安装版本，取得了比较满意的结果。它的完成，将会对HIRFL控制系统性能以及HIRFL的运行效率产生积极的影响。

基于Ms Windows的微机#gamma#谱程序设计

这篇论文里，我们对基于ms Windows的微机γ谱分析程序的数学原理，算法及程序设计进行了阐述；同时，我们也介绍了测试结果，此结果表明了拟合过程的高效性，高稳定性与准确性，并且，程序计算出的峰面积也是可接受的。 在第一部分里，全面阐述了数学原理与算法，包括由M. A. Mariscotti设计且已衍生出许多新算法的叫作DIFDIF的找峰算法，由BFGS方法实现的以χ2为拟合优值的拟合过程，在求峰下净面积及进行系统刻度中需要使用的公式等等。这些内客构成了γ谱分析程序设计哲学的核心，也是本论文的重点。 第二章里，我们一方面概括地介绍了基于面向对象思想的从系统分析到设计整个过程的系统开发文档；另一方面，我们也介绍了一些有用的程序片段，它们或者关于C++或MS Windows程序设计方法，或者关于运行时间错的处理。

Ionic liquids Supported Growth of Highly Ordered Microdroplets Induced by Fluidic Leakage at Poly(dimethylsiloxane) Interfaces

"Fluidic leakage" caused by vacuum force at the reversible sealing poly(dimethylsiloxane) (PDMS) interfaces was converted to one useable avenue, which led to formation of highly ordered surfactant microdroplets functionalized with ionic liquids (ILs). Vacuum force is the prerequisite to lead constant microsolutions to diffuse to the PDMS interfaces. Imidazolium ions of ILs rendered structural rearrangement of the surfactant aggregates and the ordered droplets formation.

Directing single-walled carbon nanotubes to self-assemble at water/oil interfaces and facilitate electron transfer

Both the behavior and the general key factors for assembling flexible SWNT films at the water/oil interface were investigated; the electron transfer, one of the most fundamental chemical processes, at the SWNT-sandwiched water/oil interface was also firstly illustrated using scanning electrochemical microscopy.