机载双基地STAP的OP-DW预处理算法及其性能研究

距离模糊杂波和杂波数据样本距离非均匀对机载双基地雷达杂波STAP性能影响严重,文章提出了一种正交投影-多普勒频移算法以实现模糊杂波抑制和非均匀性补偿.该算法首先基于待检测距离环杂波空间和时间多普勒频率信息构造空间和时间投影矩阵,重构杂波数据,消除模糊杂波,然后利用多普勒频移对杂波样本间距离非均匀性进行补偿.仿真表明:该...     

Evaluation of dilute acid and alkaline pretreatments,enzymatic hydrolysis and fermentation of napiergrass for fuel ethanol production

Napiergrass (Pennisetum purpureum Schum.) is a promising low cost raw material which does not compete with food prices, has attractive yields and an environmentally friendly farming. Dilute sulfuric acid pretreatment of napiergrass was effective to obtain high yields of sugars and low level of degradation by-products from hemicellulose. Detoxification with Ca(OH)₂ removed inhibitors but showed sugars loss. An ethanol concentration of 21 g/L after 176 h was found from the hydrolyzate using Pichia stipitis NBRC 10063 (fermentation efficiency 66%). An additional alkaline pretreatment applied to the solid fraction remaining from the diluted acid pretreatment improved the lignin removal. The highest cellulose hydrolysis values were found with the addition of β-glucosidase and PEG 6000. The simultaneous hydrolysis and fermentation of the cellulosic fraction with Saccharomyces cerevisiae, 10% (w/v) solid concentration, β-glucosidase and PEG 6000, showed the highest ethanol concentration (24 g/L), and cellulose hydrolysis values (81%). 162 L ethanol/t of dry napiergrass were produced (overall efficiency of 52%): 128 L/t from the cellulosic fraction and 34 L/t from the hemicellulosic fraction.     

暂住人口系统的数据仓库的设计

数据仓库技术将不同数据源的数据集成到数据仓库中为决策支持系统提供了一个集成的数据环境.本文以暂住人口数据仓库的设计为例,从数据源的分析、逻辑设计、数据载入、模型的选取及多维数据展示等方面阐述了数据仓库的基本设计过程.     

以产品数据仓库为核心的并行设计过程

本文阐述了以数据仓库（ＤＷ）为核心的并行设计过程邮基于ＤＷ的并行工程（ＣＥ）的实施模式；将ＤＷ技术与人工智能（ＡＩ）技术结合提出了基于ＤＷ的ＣＥ黑板结构的思想，并设计了基于此的并行产品设计系统的体系结构。