基于第一性原理的铁/铬掺杂单层MoS2电磁特性研究

文中利用第一原理计算,发现Cr/Feδ型掺杂是一种调节单层MoS₂的电磁特性的有效方法。区别于铁磁半金属,Feδ型掺杂MoS₂、Cr和Fe交替δ型共掺杂MoS₂呈现半金属亚铁磁性。Cr和Fe的3d轨道与其最近邻S的p态强耦合,其之间的虚拟跃迁遵循GKA规则。因此,Cr和Fe之间的反铁磁超交换相互作用产生了系统的亚铁磁性质。结果表明,单层MoS₂中的三维δ型掺杂提供了一种产生一维自旋极化传输通道的有效途径。     

结合B/S与C/S模式的高校教务管理系统研究及设计

高校教务管理系统与高校管理密不可分,高校在应用教务管理系统的过程中也出现了各种各样的问题,其中安全性问题、运行速度等问题受到众人关注。本文通过分析B/S与C/S系统平台模式的优缺点,以高校管理实际为出发点构建结合B/S与C/S模式的高校教务管理系统模型,互补两种模式之间的不足。     

工业Ethernet在电厂远程实时监控系统中的应用

为实现火电厂MIS,SIS,DCS三层系统管控一体化,以及不同总线产品之间的信息互连、互操作和统一组态,将工业Ethernet技术通过OPC接口融合到现场FCS中,实现电厂信息自动化管理。介绍工业Ethernet技术的现状,并结合C/S和B/S结构模式,把现场设备和管理层集成于同一层以太网上形成电厂远程监控系统,并阐述了系统B/S和C/S混合结构模型以及OPC服务器的实现。     

基于GPRS调频单频网远程监测系统的设计与实现

利用GPRS通信技术,建立B/S架构的调频单频网远程监测系统,实时监测调频单频网中各发射机和同步设备参数,具备记录、查询和自动快速报警功能,保证调频单频网系统的正常运行,实现调频单频网自动化、智能化和信息化管理。     

构建基于B/S架构的IP流量监测系统

随着网络技术的发展,人们对于网络性能的要求越来越高,因此对网络中的流量进行监测分析显得尤为重要。在参考目前已有的网络分析软件的基础上,本文面向现有常见的组网模式,讨论了IP流量监测系统的设计和实现。该系统采用B/S架构,着重分析网络拓扑中多个采集点之间时延、重传、丢包率及吞吐量等Qo S指标。此外本系统是单页面应用(SPA),具有良好的用户体验,以图表的形式显示了网络中的各项性能指标,方便网络运维工程师对网络进行监控分析。该系统目前已经在某通信公司投入运行。     

多普勒天气雷达微波系统技术体系综述

综述了多普勒天气雷达双发双收、单发双收、单发单收微波系统的系统体系、技术特点、功能模块、优缺点等,提出了多普勒天气雷达微波系统技术体系和功能模块的研发准则,比较了国内外已经开发成功的S/C/X各波段多普勒天气雷达微波系统的系统体系及功能,指出了多普勒天气雷达微波系统的发展方向。     

一种基于C/S结构的跨平台通信处理机制

基于C/S结构的应用系统客户端和服务端之间的通信处理机制是C/S结构应用系统的重要组成部分.一直以来对于兼顾高速的服务端、友好的用户界面和跨平台的通信没有一个完美的解决方案.为了平衡这一矛盾,本文提出了一种新的通信处理机制.该机制使用不同的编程语言(C 和Java)制作客户端和服务端,采用自定义标注语言和XML相结合的纯字符流进行通信.较好地解决了基于C/S结构的应用系统跨平台跨编程语言快速通信处理的问题.实验结果表明该机制能有效地解决C/S结构应用系统跨平台的通信处理问题.     

基于DM6437的车辆检测与跟踪

运用单高斯模型及形态学滤波和区域连通等技术,设计并实现了基于DM6437嵌入式系统的视频车辆检测跟踪系统。通过在DM6437平台实际运行表明,该系统能够在视频25帧/S时,实时有效地检测和跟踪车辆,具有较高准确率和稳健性。     

单Mo和Mo/S共掺杂锐钛矿相TiO_2的电子结构计算

利用基于密度泛函理论的第一性原理计算了Mo单掺杂和Mo/S共掺杂锐钛矿相TiO2的能带结构、电子分态密度、电子密度和吸收光谱。结果表明,Mo单掺杂在锐钛矿相TiO2导带底下方引入了两条主要由Mo 4d轨道组成的掺杂能级,而Mo/S共掺杂在TiO2的禁带之内共引入了四条掺杂能级,位于价带顶上方的两条主要由S 3p轨道组成,而位于导带底下方的两条掺杂能级则主要由Mo 4d和S 3p轨道杂化形成。Mo单掺杂和Mo/S共掺杂分别使TiO2的禁带宽度增大0.36 eV和0.43 eV,从而出现吸收带边的蓝移。电子密度图表明,Mo单掺杂对TiO2的晶格影响较小,但Mo/S共掺杂则使TiO2的晶格畸变程度加大。     

基于C/S与B/S的移动通信操作维护系统的设计与实现

随着Internet的普及,基于传统C/S模式的移动通信操作维护系统不能很好地满足应用需求。本文在分析C/S和B/S模式的基础上,提出建立基于C/S和B/S模式相结合的移动通信操作维护系统,给出了系统设计方案,详细介绍了系统拓扑结构、各个功能模块以及系统实现过程中的关键技术。     

Resolution Enhancement Technology:Integrated Process Solutions using OPC

DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system.     

Cost-effective test solutions for smart card and other integrated flash applications

From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.     

Theoretical analysis of the relationship between the Brillouin gain coefficient and the strain in the optical-fiber sensors

The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation.     

An improved parallel thinning algorithm with two subiterations

The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high.     

Novel fiber-optical interferometer with miniaturized probe for in-hole measurements

Today, micro-system technology and the development of new MEMS （Micro-Electro-Mechanical Systems） are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible.     

Development of the readout system for waveguide multilayer optical card

Waveguide multilayer optical card （WMOC） is a novel storage device of three-dimensional optical information. An advanced readout system fitting for the WMOC is introduced in this paper. The hardware mainly consists of the light source for reading, WMOC, motorized stages addressing unit, microscope imaging unit, CCD detecting unit and PC controlling ＆ processing unit. The movement of the precision motorized stage is controlled by the computer through Visual Basic （VB） language in software. A control panel is also designed to get the layer address and the page address through which the position of the motorized stages can be changed. The WMOC readout system is easy to manage and the readout result is directly displayed on computer monitor.     

Study of waveguide coupling efficiency in hybrid silicon lasers

This paper presents a new method to increase the waveguide coupling efficiency in hybrid silicon lasers. We find that the propagation constant of the InGaAsP emitting layer can be equal to that of the Si resonant layer through improving the design size of the InP waveguide. The coupling power achieves 42% of the total power in the hybrid lasers when the thickness of the bonding layer is 100 nm. Our result is very close to 50% of the total power reported by Intel when the thickness of the thin bonding layer is less than 5 nm. Therefore, our invariable coupling power technique is simpler than Intel＇s.     

Collinear phase-matching study of terahertz-wave generation via difference frequency mixed in GaAs and Inp

The collinearly phase-matching condition of terahertz-wave generation via difference frequency mixed in GaAs and InP is theoretically studied. In collinear phase-matching, the optimum phase-matching wave hands of these two crystals are calculated. The optimum phase-matching wave bands in GaAs and lnP are 0.95-1.38μm and 0.7-0.96μm respectively. The influence of the wavelength choice of the pump wave on the coherent length in THz-wave tuning is also discussed. The influence of the temperature alteration on the phase-matching and the temperature tuning properties in GaAs crystal are calculated and analyzed. It can serve for the following experiments as a theoretical evidence and a reference as well.     

Effects of the alloy compositions on the phonon-polaritons in ternary mixed crystals

Composition dependence of bulk and surface phonon-polaritons in ternary mixed crystals are studied in the framework of the modified random-element-isodisplacement model and the Bom-Huang approximation. The numerical results for Several Ⅱ - Ⅵ and Ⅲ- Ⅴ compound systems are performed, and the polariton frequencies as functions of the compositions for ternary mixed crystals AlxGa1-xAs, GaPxAS1-x, ZnSxSe1-x, GaAsxSb1-x, GaxIn1-xP, and ZnxCd1-xS as examples are given and discussed. The results show that the dependence of the energies of two branches of bulk phonon-polaritons which have phonon-like characteristics, and surface phonon-polaritons on the compositions of ternary mixed crystals are nonlinear and different from those of the corresponding binary systems.     

New insert layer structure OLEDs

An insert layer structure organic electroluminescent device（OLED） based on a new luminescent material （Zn（salen）） is fabricated. The configuration of the device is ITO/CuPc/NPD/Zn（salen）/Liq/LiF/A1/CuPc/NPD/Zn（salen）/Liq/LiF/A1. Effective insert electrode layers comprising LiF（1nm）/Al（5 nm） are used as a single semitransparent mirror, and bilayer cathode LiF（1 nm）/A1（100 nm） is used as a reflecting mirror. The two mirrors form a Fabry-Perot microcavity and two emissive units. The maximum brightness and luminous efficiency reach 674 cd/m^2 and 2.652 cd/A, respectively, which are 2.1 and 3.7 times higher than the conventional device, respectively. The superior brightness and luminous efficiency over conventional single-unit devices are attributed to microcavity effect.