Monitoring Crustal Deformations with Radar Interferometry： A Review

The crustal movements, probably motivating earthquakes, are considered as one of the main geodynamic sources. The quantitative measurements of ground surface deformations are vital for studying mechanisms of the buried faults or even estimating earthquake potential. A new space-geodetic technology, synthetic aperture radar interferometry (InSAR), can be applied to detect such large-area deformations, and has demonstrated some prominent advantages. This paper reviews the capacity and limitations of InSAR, and summarises the existing applications including some of our results in studying the earthquake-related crustal motions.Finally it gives the outlook for the future development of InSAR.     

没食子酰基金丝桃甙的抗氧化性及其构效关系研究

目的　通过对没食子酰基金丝桃甙 (Gq)清除氧自由基作用的测定 ,探讨Gq的抗氧化性并对其抗氧化机理与结构之间的关系进行探讨。方法　分别采用黄嘌呤 黄嘌呤氧化酶体系及Fenton反应体系 ,测定Gq对超氧阴离子自由基 (SAFR)和羟基自由基 (HFR)的清除作用 ,得出清除率与浓度之间的相关关系 ,求出IC50 值 ,以表示其抗氧化能力。对比分析Gq及天然抗氧剂槲皮素和芦丁的化学结构 ,探讨抗氧化机理与结构之间的构效关系。 结果　Gq对氧自由基具有明显的清除活性 ,清除SAFR和HFR的IC50 值分别为 4 0 .8μmol·L-1和 33.5 μmol·L-1,远小于阳性对照物槲皮素 (分别为 114 .0 μmol·L-1和 10 0 .8μmol·L-1)及芦丁 (15 2 .0 μmol·L-1和 91.4 μmol·L-1)。结论　Gq具有明显的抗氧化性 ,其抗氧化活性与其分子结构中多元酚结构有关 ,但其抗氧化机理不同于小分子的没食子酰类衍生物     

ICA based speckle filtering for target extraction in SAR images using adaptive space separation

A novel approach based on independent component analysis (ICA) for speckle filtering and target extraction of synthetic aperture radar (SAR) images is proposed using adaptive space separation with weighted information entropy (WIE) incorporated. First the basis and the independent components are respectively obtained by ICA technique, and WIE of the image is computed; then based on the threshold computed from function T-WIE (threshold versus weighted-information-entropy), independent components are adaptively separated and the bases are classified accordingly. Thus, the image space is separated into two subspaces: "clean" and "noise". Then, a proposed nonlinear operator ABO is applied on each component of the 'clean' subspace for further optimization. Finally, recovery image is obtained reconstructing this subspace and target is easily extracted with binarisation. Note that here T-WIE is an interpolated function based on several representative target SAR images using proposed space separation algorithm.