为企业回身订做的.NET服务器产品——.NET Enterprise Servers

微软在2000年11月中旬,推出的以.NET平台开发的产品Microsoft .NET Enterprise 2000Servers(以下简称为.NETEnterprise Servers)里,是由表格中所看到的7套.NET新产品所共同组成的。顺带一提的是,在微软.NET Enterprise Servers还有一款Mobile Information 2001Server,但这款软件还是Beta版本,没有正式发表,所以在此我们就不再单独介绍了,如有兴趣了解相关信息,可到www.microsoft.com/servers/net/查询。 Microsoft.NET EnterpriseServers服务器系统产品能协助企业更快速的集成、管理以Web为基础     

基于GPRS的GIS局部放电监测系统

针对GIS传统在线监测时现场数据不能及时传输,导致故障不能及时的预测、报警和处理等问题,开发了基于GPRS的GIS远程在线监测系统。该系统以AT89S51为主控制芯片,重点阐述GPRS的组网方式以及具体实现过程,并在LabWindows/CVI下编写PC端服务器程序。通过工程实践证明,本系统能准确、可靠、实时对GIS局部放电进行测量、发送、管理。     

基于Pocket PC的GIS.NET框架分析与研究

嵌入式地理信息系统是导航、定位、地图查询和空间数据管理的一种理想解决方案,Windows Mobile则为基于Pocket PC上的应用程序的开发提供了一个坚实的平台。随着Microsoft.NET Compact Framework 2.0的出现,美国Geo-frameworks公司搭建了基于Pocket PC的GIS.NET框架,从而使Windows Mobile平台上地理信息系统的实现更加高效。分析了GIS.NET的框架设计,并对该框架的功能进行扩展研究,指出了该框架的应用价值。     

补考管理信息系统的实现

本设计基于B/S模式,运用ASP.NET技术,采用功能强大的Microsoft Visual Studio 2008作为开发工具、Sql Server作为数据库而开发出来的综合测评管理系统。开发本系统可减轻教务工作压力,比较系统地对教务、教学上的各项服务和信息进行管理。同时,可以减少劳动力的使用,加快查询速度、加强管理,使各项管理更加规范化。     

基于GPRS的城市照明电缆防盗报警系统

本文分析了当前照明电缆防盗技术的原理和缺陷,提出了采用漏电流技术实现理想的照明电缆防盗技术要求。利用该技术,设计出基于GPRS/GSM通讯网络的城市照明电缆防盗报警系统。     

基于C#.NET的光通讯产品测试系统开发

在以Microsoft.NET为测试系统的开发平台上,结合C#语言和.NET技术,设计了大容量光交换产品的功能测试系统。该系统的投入和使用体现出C#.NET开发系统的强大优势,优化了测试系统框架,提升了系统的管理和使用效率,统一的测试系统框架下,升级产品的测试系统开发效率可以有效提升。     

基于GPRS通信的10KV变电站系统的上位机监控系统设计

本系统主要是针对GPRS通讯的10KV变电站系统的综合自动化监控系统设计,以计算机为基本装置,实现对过程的直接调节监视,对被控现场完成过程数据的处理与实时控制,实现对过程状态的显示、报警、记录和操作等集中化处理.上位机基于VB+Accesss,以无线方式接收到测控设备传来的测量和信息量后,以图形图像方式实时显示遥信量,以达到监视的目的,同时采集到的数据、报警信息和操作人员的操作数据会自动保存到数据库中,以便操作人员查询,同时上位机进行遥控、遥调操作时,将控制信号发给测控设备以达到控制的目的.     

城市公交查询系统的设计与实现

研究了基于MO的城市公交查询系统的设计,探讨了换乘算法的基本思想及其实现。以焦作市为例,系统选用GIS组件MapObjects作为地理信息系统二次开发组件,通用语言Visual Basic6.0作为开发工具,Microsoft Access2000作为后台数据库,开发城市公交查询系统,实现了地图的放大、缩小、漫游等GIS软件的基本功能,以及公交换乘方案和地名的查询等空间查询功能。     

基于NET的网络文件存储管理系统设计与实现

随着网络技术的发展,网络文件存储系统日益普及。为了实现网络资源共享,提高资源利用率,通过ASP.NET技术,采用ASP.NET 2.0和C#开发语言,以Microsoft Visual Studio 2008作为集成开发环境,结合SQL Server 2005数据库软件,设计实现了一个相对完善的网络文件存储管理系统。系统利用B/S模式结构,实现了用户登录、文件夹管理以及文件管理等功能,为网络文件管理提供了高效便捷的资源交换手段,具有一定的实用价值。     

气象灾害数据库管理与分析系统开发与实现

为解决历年气象灾害灾情数据录入和查询手段匮乏问题,及时准确地分析气象灾害的发生发展情况,为气象灾害风险评估和决策服务提供依据。设计和开发气象灾害数据库管理与分析系统,实现包括台风、雷电、冰雹等十余种气象灾害信息的录入、修改、删除、查询、检索、统计和分析功能。该系统主要基于C#.NET语言开发,采用B/S架构,提供GIS可视化界面,可以基于灾情信息在后台自动计算灾情指数,为灾害的评估提供直接数据支持。     

Performance improvement in tensile-strained In/sub 0.5/Al/sub 0.5/As/In/sub x/Ga/sub 1-x/As/In/sub 0.5/Al/sub 0.5/As metamorphic HEMT

This paper proposes a In/sub 0.5/Al/sub 0.5/As/In/sub x/Ga/sub 1-x/As/In/sub 0.5/Al/sub 0.5/As (x=0.3-0.5-0.3) metamorphic high-electron mobility transistor with tensile-strained channel. The tensile-strained channel structure exhibits significant improvements in dc and RF characteristics, including extrinsic transconductance, current driving capability, thermal stability, unity-gain cutoff frequency, maximum oscillation frequency, output power, power gain, and power added efficiency.     

Very low-noise Al/sub 0.3/Ga/sub 0.7/As/Ga/sub 0.65/In/sub 0.35/As/GaAs single quantum-well pseudomorphic HEMTs

AlGaAs/GaInAs/GaAs pseudomorphic HEMTs with an InAs mole fraction as high as 35% in the channel has been successfully fabricated. The device exhibits a maximum extrinsic transconductance of 700 mS/mm. At 18 GHz, a minimum noise figure of 0.55 dB with 15.0 dB associated gain was measured. At 60 GHz, a minimum noise figure as low as 1.6 dB with 7.6 dB associated gain was also obtained. This is the best noise performance yet reported for GaAs-based HEMTs.<>     

A 12 /spl times/ 12 In/sub 0.53/Ga/sub 0.47/As-In/sub 0.52/Al/sub 0.48/As avalanche photodiode array

We report a 12 /spl times/ 12 In/sub 0.53/Ga/sub 0.47/As-In/sub 0.52/Al/sub 0.48/As avalanche photodiode (APD) array. The mean breakdown voltage of the APD was 57.9 V and the standard deviation was less than 0.1 V. The mean dark current was /spl sim/2 and /spl sim/300 nA, and the standard deviation was /spl sim/0.19 and /spl sim/60 nA at unity gain (V/sub bias/ = 13.5 V) and at 90% of the breakdown voltage, respectively. External quantum efficiency was above 40% in the wavelength range from 1.0 to 1.6 /spl mu/m. It was /spl sim/57% and /spl sim/45% at 1.3 and 1.55 /spl mu/m, respectively. A bandwidth of 13 GHz was achieved at low gain.     

Al/sub 0.3/Ga/sub 0.7/As/In/sub x/Ga/sub 1-x/As (0/spl les/x/spl les/0.25) doped-channel field-effect transistors (DCFET's)

The properties of both lattice-matched and strained doped-channel field-effect transistors (DCFET's) have been investigated in AlGaAs/In/sub x/Ga/sub 1-x/As (0/spl les/x/spl les/0.25) heterostructures with various indium mole fractions. Through electrical characterization of grown layers in conjunction with the dc and microwave device characteristics, we observed that the introduction of a 150-/spl Aring/ thick strained In/sub 0.15/Ga/sub 0.85/As channel can enhance device performance, compared to the lattice-matched one. However, a degradation of device performance was observed for larger indium mole fractions, up to x=0.25, which is associated with strain relaxation in this highly strained channel. DCFET's also preserved a more reliable performance after biased-stress testings.<>     

Morphological and electrical characterization of SixCryCzBv thin films

Si_xCr_yC_zB_v thin films with several compositions have been studied for integration of high precision resistors in 0.8 μm BICMOS technology. These resistors, integrated in the back-end of line, have the advantage to provide high level of integration and attractive electrical behavior in temperature, for analog devices. The film morphology and the structure have been investigated through transmission electron microscopy analysis and have been then related to the electrical properties on the base of the percolation theory. According to this theory, and in agreement with experimental results, negative thermal coefficient of resistance (TCR) has been obtained for samples with low Cr content, corresponding to a crystalline volume fraction below the percolation threshold.Samples with higher Cr content exhibit, instead, a variation of the TCR as a function of film thickness: negative TCR values are obtained for thickness lower than 5 nm, corresponding to a crystalline volume fraction below the percolation threshold; positive TCR are obtained for larger thickness, indicating the establishment of a continuous conductive path between the Cr rich grains. This property seems to be determinant in order to assure the possibility to obtain thin film resistors almost independent on the temperature.     

Highly linear Al/sub 0.3/Ga/sub 0.7/N-Al/sub 0.05/Ga/sub 0.95/N-GaN composite-channel HEMTs

We report an Al/sub 0.3/Ga/sub 0.7/N-Al/sub 0.05/Ga/sub 0.95/N-GaN composite-channel HEMT with enhanced linearity. By engineering the channel region, i.e., inserting a 6-nm-thick AlGaN layer with 5% Al composition in the channel region, a composite-channel HEMT was demonstrated. Transconductance and cutoff frequencies of a 1 /spl times/100 /spl mu/m HEMT are kept near their peak values throughout the low- and high-current operating levels, a desirable feature for linear power amplifiers. The composite-channel HEMT exhibits a peak transconductance of 150 mS/mm, a peak current gain cutoff frequency (f/sub T/) of 12 GHz and a peak power gain cutoff frequency (f/sub max/) of 30 GHz. For devices grown on sapphire substrate, maximum power density of 3.38 W/mm, power-added efficiency of 45% are obtained at 2 GHz. The output third-order intercept point (OIP3) is 33.2 dBm from two-tone measurement at 2 GHz.     

Comparison between Pt/TiO2/Pt and Pt/TaOX/TaOY/Pt based bipolar resistive switching devices

Nonvolatile memories have emerged in recent years and have become a leading candidate towards replacing dynamic and static random-access memory devices. In this article, the performances of TiO₂ and TaO₂ nonvolatile memristive devices were compared and the factors that make TaO₂ memristive devices better than TiO₂ memristive devices were studied. TaO₂ memristive devices have shown better endurance performances (10⁸ times more switching cycles) and faster switching speed (5 times) than TiO₂ memristive devices. Electroforming of TaO₂ memristive devices requires~4.5 times less energy than TiO₂ memristive devices of a similar size. The retention period of TaO₂ memristive devices is expected to exceed 10 years with sufficient experimental evidence. In addition to comparing device performances, this article also explains the differences in physical device structure, switching mechanism, and resistance switching performances of TiO₂ and TaO₂ memristive devices. This article summarizes the reasons that give TaO₂ memristive devices the advantage over TiO₂ memristive devices, in terms of electroformation, switching speed, and endurance.     

Electrooptic ferroelectric Na/sub 0.5/K/sub 0.5/NbO/sub 3/ films

We report on waveguiding and electrooptic properties of epitaxial Na/sub 0.5/K/sub 0.5/NbO/sub 3/ films grown by radio-frequency magnetron sputtering on Al/sub 2/O/sub 3/(11_02) single crystal substrates. High optical waveguiding performance has been demonstrated in infrared and visible light. The in-plane electrooptic effect has been recorded in transmission using a transverse geometry. At dc fields, the effective linear electrooptic coefficient was determined to 28 pm/V, which is promising for modulator applications.