Retrieval of total suspended matter concentration from Gaofen-1 Wide Field Imager (WFI) multispectral imagery with the assistance of Terra MODIS in turbid water – case in Deep Bay

This study proposed a method for developing high spatial resolution Gaofen-1 satellite (GF-1) Wide Field Imager (WFI)-based total suspended matter concentration (C_TSM) retrieval model with the assistance of Moderate Resolution Imaging Spectroradiometer (MODIS) data, using the Deep Bay in China as a case. Based on long-term calibrated C_TSM measurements of optical backscatter (OBS) 3A turbidity and temperature monitoring system of two stationary stations from January 2007 through November 2008, 33 match-ups were selected to build an exponential retrieval model for MODIS atmospherically corrected remote-sensing reflectance (R_rs) ratio (R_rs,645/R_rs,555). Validation of the MODIS model showed well agreement with the seven in situ C_TSM measurements with a root mean squared error (RMSE) of 5.06 mg l^?1 and a coefficient of determination R² of 0.80. Aided with six MODIS retrieved C_TSM products, different band combinations (single band (R_rc,660), band subtraction (R_rc,660–R_rc,560), band ratio (R_rc,660/R_rc,560), and total suspended matter index at 660 nm band (TSMI₆₆₀) were evaluated for simultaneous GF-1 WFI Rayleigh-corrected reflectance (R_rc). The results showed that the exponential model based on the Rayleigh-corrected reflectance ratio (R_rc,660/R_rc,560) could achieve acceptable accuracy, with RMSE of 14.80 mg l^?1 and R² of 0.62. The proposed method would be helpful for dynamic monitoring in the Deep Bay, and more important could also provide an alternative approach for studies when in situ measurements are unreachable.     

造纸厂负荷优化调度系统

以造纸厂生产实际为背景,给出了间隙式生产设备－蒸球优化调度的方法。仿真结果表明,该方法在满足纸浆实际需要的前提下,可以节能降耗。     

Characteristics of an electron source of a surface‐conduction electron‐emitter display

Abstract— The electron source is an essential part of a surface‐conduction electron‐emitter display (SED). An electron source for an SED was obtained after certain procedures were performed. By introducing a carbon atmosphere, the electron‐emission characteristics of a SED were studied experimentally. The electron‐emission characteristic curves were drawn after comparing the experimental data of the electron source obtained in a vacuum environment with the data obtained in a carbon atmosphere, from which it had proved that a carbon atmosphere could significantly improve the electron‐emission characteristics of a SED. As a result, both the device current and the emission current had become stronger and the efficiency of surface‐conduction electron emission had been improved significantly. The possible reasons were analyzed: more carbon, which could possibly form the electron‐emission region of a SED, was produced from the carbon atmosphere during the electrical activation process.     

分布式实时系统双工容错技术研究

本文介绍一个高可用性的分布式实时双工系统。文中首先建立了系统模型,通过模型给出了系统高可用性的定量公式,最后着重介绍了实现双工的几种主要技术,包括机组切换、数据恢复和双工结果处理等。     

酸气回注方案关键技术研究

酸气回注是一种安全环保的酸气处理方式,其原理是将酸气压缩后通过井筒回注到已废弃的产层或水层中.基于酸气不同组分的相平衡机理进行酸气回注方案设计,分析不同相态的输送方式,结合酸气脱水、增压、管线腐蚀和水合物防止等关键工艺技术,优选合理的回注工艺参数.     

基于移动Agent的新型分布式入侵检测系统

通过阐述入侵检测系统的基本概念和移动Agent的优点,并将移动Agent技术与分布式技术相结合,提出了一种基于移动Agent的新型分布式入侵检测系统DIDSBMA,它具有传统入侵检测技术无法比拟的优势,极大地提高了系统的稳定性、可测量性和容错性,真正实现了分布式入侵检测。     

IC平台专用标准产品的快速定制化

当前数量飞速增长的嵌入式软件及最近的电子掩膜可编程嵌入式门阵列定制了专用标准产品(ASSP)。文中所提出的方案致力于解决两方面的问题一是对较高灵活性的高度要求;二是对缩短产品生产周期的需求。这可以从使用单个通道可编程逻辑和相应的软硬件协同设计流程来解决。采用0.3μm的CMOS工艺,系统所需的硅片面积为23mm2。嵌入式通道可编程逻辑大约占系统总面积的30%。     

一种空间RSSR传动机构的运动综合法

空间ＲＳＳＲ机构是最基本，最常用的空间铰链四杆机构，可用来实现主从动杆对应角位移等。目前已有若干著名研究了实现主从动杆对应角位移的空间ＲＳＳＲ机构的运动综合合问题，如方向余弦矩阵法、回转向量法。     

非线性轴承-转子系统的不平衡响应分析

由于轴承转子系统支承油膜非线性恢复力的作用，使得作用在轴承上的转子的不平衡响应行为比较复杂，用修正的短轴承理论模型对一个实际的轴承转子进行了动力学分析计算，得出了在一定的不平衡下，各种转速的不平衡响应，特别是计算出了半频和倍频出现的分叉点，计算结果表明，轴承－转子系统的半频涡动分叉点与转子转速，转子上所受载荷和不平衡大小均有关系。     

CMOS有源象素图象传感器

介绍了ＣＭＯＳ图象传感器一般结构、ＣＭＯＳ图象传感器的象元结构和在片模拟信号处理，并介绍了两种典型的ＣＭＯＳ有源象素图象传感器，最后指出了ＣＭＯＳ有源象素图象传感器的发展动向