数字地震台电源远程监控系统

以STC89C52单片机为核心,开发基于"十五"网络的地震台站电源远程监控系统,实时的监控台站仪器设备的状态并收取状态参数,实现设备复位操作及故障报警,可以提高地震台网中心仪器运行效率。     

青海省国土资源厅为联点扶贫的莫日通村送去85台太阳能户用电源

9月4日,清海省国土资源厅宋建国副厅长一行7名干部到联点扶贫的天峻县快尔玛乡莫日通村,开展扶贫慰问、联点帮扶活动,并给78户牧业户送去了总价值25.5万元的85台太阳能户用电源,确保每户拥有一套,通过太阳能户用电源的应用,牧民可以用电力照明租收听看广播电视,     

日本Mw9.0地震前的舒曼谐振异常分析

2011年3月11日日本本州岛东海岸附近海域发生了Mw9.0地震.基于中国云南的舒曼谐振(SR)观测站的磁场观测数据,分析了与该次地震有关的SR疑似异常现象.分析表明,震前3 4天低阶谐振开始出现比较明显的幅度增强现象,以2011年3月8日(北京时间)这一天的现象最明显,南北向在7:00-10:00和12:00-15:00异常比较明显,而东西向只在12:00-15:00异常相对比较强.根据对2011年3月1-11日及对应每天前后各15天共41天的数据的联合分析,3月8日部分时间段的低阶谐振磁场差明显高于一倍甚至两倍标准差;相比而言,正常的一天内各阶磁场差要明显低于一倍标准差.最后,根据一些日本地震学者提出的SR异常机理,进一步分析了在云南观测站能观测到日本地震异常的可能性.结果表明,在永胜观测站可以观测到日本地震引起的一阶到三阶SR异常,与发现的异常主要集中在低阶的现象比较吻合.     

高空站后备电源维护方法

对目前高空站所使用的后备电源的维护方面,参考有关资料,结合台站的工作经验,总结出备份电源的维护与保障方法,为各台站在日常使用备份电源时提供一定参考。     

鹤岗市污水处理厂自动化系统信号和电源电涌保护器的选择

1引言鹤岗市污水处理厂对污水的处理净化分成多个过程来完成．在过程控制中分段采用几个独立的PLC系统进行控制,对其中的PLC系统加装电源型电涌保护器和信号型电涌保护器．围绕PLC控制机房敷设了环形地网,对机房内设备进行了等电位连接。本文主要探讨其中一个污水池开关量信号线在安装信号保护器过程中遇到的问题。     

Estimating overland flow erosion capacity using unit stream power

Soil erosion caused by water flow is a complex problem. Both empirical and physically based approaches were used for the estimation of surface erosion rates. Their applications are mainly limited to experimental areas or laboratory studies. The maximum sediment concentration overland flow can carry is not considered in most of the existing surface erosion models. The lack of erosion capacity limitation may cause over estimations of sediment concentration. A correlation analysis is used in this study to determine significant factors that impact surface erosion capacity. The result shows that the unit stream power is the most dominant factor for overland flow erosion which is consistent with experimental data. A bounded regression formula is used to reflect the limits that sediment concentration cannot be less than zero nor greater than a maximum value. The coefficients used in the model are calibrated using published laboratory data. The computed results agree with laboratory data very well. A one dimensional overland flow diffusive wave model is used in conjunction with the developed soil erosion equation to simulate field experimental results. This study concludes that the non-linear regression method using unit stream power as the dominant factor performs well for estimating overland flow erosion capacity.     

可编程序控制器的多机联用

多台可编程序控制器通过输入、输出点的直接连接,传递命令、状态和数据,实现多机联用系统。     

On the Spectral Index－Flux Density Relation for Large Samples of Radio Sources

We present new statistical results on the spectral index-flux density relation for large samples of radio sources using archival data of the most sensitive surveys, such as 6C, Miyun, WENSS, B3, NVSS, GB87. Instrumental selection effects and the completeness of the catalogs are discussed. Based on the spectral indices calculated for about 200 000 sources from the WENSS (327 MHz) and NVSS (1.4 GHz) catalogs, we obtained (1) The median spectral index increases from amed --0.9 toαmed --0.8 (Svαvα), while S327 flux densities decrease from 0.1 Jy down to 25mJy. The median spectral indices nearly show no variation within the error bars when the flux density is larger than 0.1 Jy. (2) A dependence of the fraction of ultra-steep spectrum sources (USS, -1.5 <α<-1.0), steep spectrum sources (SSS, -1.0 <α< -0.5) and flat spectrum sources (FSS, -0.5≤α≤0.0) is partly responsible for the spectral flattening. Another contribution to the spectral flattening comes from the variation of αmed of steep spectrum so     

713雷达数字化终端技术分析

对雷达的探测原理和工作过程进行了简单介绍，重点对７１３雷达的数字化终端ＣＴＣ－８７系统的组成及组成系统的各分机模块，如：视频积分器，天线控制器，雷达定标器，计算机接口的组成和原理进行了深入分析。