超声相控阵检测焊缝三维可视化

介绍超声相控阵扇形（s型）扫查法对焊缝实施全体积检测的优势：信号（色码幅度）实时显示,自动存储,特别是检测数据可三维（5D）显示,又可多视角观测,缺陷四定（定位、定性、定量、定级）更方便,符合国际权威法规ASME最新版（2011a）的有关要求。期盼UT人员能在日常焊缝检测中熟练运用相控阵三维可视化技术。     

TFM实时成像技术在缺陷检测中的应用

在压力容器的超声检测中,为解决传统相控阵（PA）二维成像存在缺陷图像畸变,难以准确定性等问题,采用1种基于全聚焦法（TFM）的实时超声成像技术,使用一维线阵和二维面阵分别对孔等典型实际缺陷进行扫查,获得缺陷的二维和三维图像,从定量角度对比分析2者的准确度。结果表明:该方法获得的三维图像测量误差在8%以内,具有更高的精确度和检出率,对于孔类缺陷的还原度更高,这对于缺陷检测与评估以及和特种设备的安全生产具有重要意义。     

GeoChip-based analysis of the microbial community functional structures in simultaneous desulfurization and denitrification process

The elemental sulfur （S^0） recover）, was evaluated in the presence of hi,ate in two development models of simultaneous desulfurization and denitrification （SDD） process. At the loading rates of 0.9 kg S/（m^3.day） for sulfide and 0.4 kg N/（m^3.day） for nitrate, SO conversion rate was 91.1% in denitrifying sulfide removal （DSR） model which was higher than in integrated simultaneous desulfurization and denitrification （ISDD） model （25.6%）. A comprehensive analysis of functional diversity, structure and metabolic potential of microbial communities was examined in two models by using functional gene array （GeoChip 2.0）. GeoChip data indicated that diversity indices, community structure, and abundance of functional genes were distinct between two models. Diversity indices （Simpson＇s diversity index （1/D） and Shannon-Weaver index （H′）） of all detected genes showed that with elevated infiuent loading rate, the functional diversity decreased in ISDD model but increased in DSR model. In contrast to ISDD model, the overall abundance of dsr genes was lower in DSR model, while some functional genes targeting from nitrate-reducing sulfide-oxidizingbacteria {NR-SOB）, such as Thiobacillus denitrficans, Sulfurimonas denitrificans, and Paracoccus pantotrophus were more abundant in DSR model which were highly associated with the change of SO conversion rate obtained in two models. The results obtained in this study provide additional insights into the microbial metabolic mechanisms involved in ISDD and DSR models, which in turn will improve the overall performance of SDD process.     

电离层环境对地空信息系统的影响效应

目的为了减缓电离层对卫星通信、全球卫星导航系统、星载合成孔径雷达等系统的影响,提高系统的环境适应性。方法由穿越电离层的无线电信号传播原理出发,结合各种系统的工作原理,给出电离层影响的分析方法。结果针对电离层闪烁、极化旋转、时延和色散等传播效应造成卫星通信误码率上升、卫星导航定位误差增大、SAR图像偏移和分辨率下降等影响,分析给出了效应补偿和减缓应对方法。结论电离层延迟效应可以由电离层实测值或者模型来进行校正,而闪烁效应大多需采用规避的措施来减缓其影响。