综合业务以太网络的实现     

魏星宇  罗克露  郭文生 《成都信息工程学院学报》2005,20(5):546-549

Token Bos经过适当修改和发展可以移植到以太网上，再通过对硬实时协议栈RTCC的改造，可以将两种协议融合为一种基于以太网技术的具有传输硬实时、软实时和非实时数据功能的综合业务网络访问控制技术（ISE），即可在一套系统中同时实现传统网络业务和硬实时数据传输业务。  相似文献   

微波高功率固态放大器技术综述     

韩江安  马凯学 《南京气象学院学报》2017,9(1):8-14

微波集成电路在民用和军用电子中起到至关重要的作用.在微波集成电路领域,高功率的功率放大器为发射机提供足够的信号功率输送到自由空间中,是其不可缺少的关键部件.基于学术研究和商用产品线情况,综述了微波功率放大器芯片的发展情况.首先讨论了各种微波毫米波功率放大器的制造技术,按照半导体器件可以归类为砷化镓、氮化镓、互补金属氧化物半导体和锗化硅等;接着讨论了微波芯片功放的设计技术用以满足高功率、宽带和高效率的指标要求;最后总结了各类微波固态功率放大器的工艺和设计技术,为芯片设计人员提供了全面的设计参考.  相似文献   

Daily streamflow trends in Western versus Eastern Norway and their attribution to hydro-meteorological drivers     

Amalie Skålevåg  Klaus Vormoor 《水文研究》2021,35(8):e14329

Regional warming and modifications in precipitation regimes has large impacts on streamflow in Norway, where both rainfall and snowmelt are important runoff generating processes. Hydrological impacts of recent changes in climate are usually investigated by trend analyses applied on annual, seasonal, or monthly time series. None of these detect sub-seasonal changes and their underlying causes. This study investigated sub-seasonal changes in streamflow, rainfall, and snowmelt in 61 and 51 catchments respectively in Western (Vestlandet) and Eastern (Østlandet) Norway by applying the Mann–Kendall test and Theil–Sen estimator on 10-day moving averaged daily time series over a 30-year period (1983–2012). The relative contribution of rainfall versus snowmelt to daily streamflow and the changes therein have also been estimated to identify the changing relevance of these driving processes over the same period. Detected changes in 10-day moving averaged daily streamflow were finally attributed to changes in the most important hydro-meteorological drivers using multiple-regression models with increasing complexity. Earlier spring flow timing in both regions occur due to earlier snowmelt. Østlandet shows increased summer streamflow in catchments up to 1100 m a.s.l. and slightly increased winter streamflow in about 50% of the catchments. Trend patterns in Vestlandet are less coherent. The importance of rainfall has increased in both regions. Attribution of trends reveals that changes in rainfall and snowmelt can explain some streamflow changes where they are dominant processes (e.g., spring snowmelt in Østlandet and autumn rainfall in Vestlandet). Overall, the detected streamflow changes can be best explained by adding temperature trends as an additional predictor, indicating the relevance of additional driving processes such as increased glacier melt and evapotranspiration.  相似文献   

CINRAD/SA雷达发射机驱动级工作原理及检修技术探讨     

陈忠勇 《气象科技》2012,40(1):1-4

新一代多普勒天气雷达CINRAD/SA发射机放大链驱动级是发射机中的关键部件,占有很重要的地位,其技术指标基本决定了发射机的输出高频脉冲宽度及频谱,直接影响雷达系统的质量。详细讨论了发射机放大链驱动级的硬件组成及工作原理,并对其相关线路作了进一步分析,介绍了正确的调试方法,给出了几个关键点波形及相关时序,根据台站工作的实际经验,结合相关报警信息,探讨了基本维修思路,总结了一些快速有效的检修方法,希望能为新一代多普勒天气雷达技术保障提供有益的借鉴。  相似文献   

可编程增益放大器在海洋环境监测中的应用及其接口     

余家栋 《海洋科学》1989,13(2):33-37

文中提出一种性能优良的单片集成数字增益设定器LFl3006/7,它与集成运算放大器组成可编程增益放大器PGA电路,也可组成具有二进制或者十进制等不同增益档次的程序可测控的仪表放大器。微机系统通过接口电路对它实施智能式的增益切换,优化了仪器测量的动态范围和精度,这对人们无法手动干预的环境监测或海洋遥测过程有特殊的意义。  相似文献   

Window 9X下利用VtoolsD开发硬件中断设备驱动程序     

尚凤军  王海霞 《物探化探计算技术》2002,24(4):375-379

作者在本文中介绍了基于PC和Windows 9X平台下用中断方式实现数据采集的方法；并对虚拟设备驱动程序（VxD）和VtoolsD工具箱进行了简要介绍，通过对源代码的分析，说明了实时硬件中断VxD的实现过程。  相似文献   

A portable instrument for the measurement of salinity of rainwater using FET's     

Rao  A. M. 《Pure and Applied Geophysics》1985,123(2):344-347

A portable salinity meter with field effect transistors for the continuous recording of salinity of rainwater is described. The variations in salinity are converted into current variations by using a D.C. differential amplifier and is recorded on an Esterline Angus Recorder. The Meter enables us to measure rainfall intensity as well as salinity simultaneously. The chief advantages of the present instrument are that it is portable and has a range of measurement from 1×10^–4 to 1×10^–1 ppm on a linear scale.  相似文献   

短周期烟记录地震仪技术改进试验研究     

杨成玉  陈仲范 《华北地震科学》1994,12(3):75-80

针对烟记录地震仪存在的问题，采取仅改动其放大器、电源与记录部分，利用现有拾震器和大滚筒记录器，投入少量资金，即可改造成适合台站使用的新型ＤＹＪ－１型短周期墨水记录地震仪。  相似文献   

泥沙模型试验测控系统   总被引：5，自引：0，他引：5  

蔡守允  陆长石 《海洋工程》1997,(3)

本文介绍了成功地应用于国家“八五”重点科技攻关项目——三峡工程回水变动区涪陵河段泥沙模型试验的测控系统，简述了对模型试验进口的含沙量、流量和泥沙颗粒级配的控制原理和方法，重点介绍了微机尾水位自动控制以及流速、水位和波浪的多点同步采集与处理系统。  相似文献   

个人防火墙突破技术研究与防范措施     

胡勇  吴少华  周安民 《成都信息工程学院学报》2008,23(3):235-238

首先分析了Windows的网络结构,并在此基础上分析了包括SPI封包截获技术、TDI过滤驱动、NDIS钩子驱动在内的各种个人防火墙技术,然后根据个人防火墙特点以及技术缺陷,给出了几种穿透防火墙的方法以及相应的代码,最后提出改进个人防火墙的一些建议。  相似文献