Yushu earthquake synergic analysis using multimodal SAR datasets

The large earthquake measuring 7.1 on the Richter scale that occurred in Yushu County, Qinghai Province, China, on April 14, 2010, caused a huge loss of life and major damage to people’s properties. Using three modal synthetic-aperture radar (SAR) datasets, wide-swath SAR, interferometric SAR and polarimetric SAR, the following studies were conducted: (1) From Radarsat-2 wide swath SAR data, the regional geological structures and lithologic distribution characteristics of the Yushu earthquake were analyzed. (2) Using advanced land observing satellite/phased array L-band interferometric SAR data, the coseismic deformation field of the Yushu earthquake was obtained, and the size and spatial distribution of deformation were studied combining with the result of regional geological background analysis. (3) From Radarsat-2 polarimetric SAR data, the H-α-ρ method was used to extract the spatial distribution of building collapse caused by the earthquake in the Yushu urban area, and the reasons for the severe earthquake damage to buildings are also discussed and assessed. The study results demonstrate the effectiveness and important potential of using multimodal SAR data for synergic analysis and assessment of earthquake disasters.     

U-Pb dating of detrital zircons from the Wudangshan Group in the South Qinling and its geological significance

U-Pb dating was made by the LA-ICP-MS method for detrital zircons from the Wudangshan volcanic-sedimentary succession in the South Qinling. Samples comprise quartz sandstones of the Wudangshan Group collected from the base of the Yangping Formation and an upper layer of the Shuangtai Formation overlain its volcanic sequence, and two river-sand collections from the drainage systems cutting across the two formations, respectively. The results show that the Yangping detrital zircons are dominated by 830–780 Ma grains with a minor population of ~1.0–0.84 Ga and sporadic grains of ~2.6, ~2.4 and 2.0 Ga, whereas the Shuangtai zircons yield an upper intercept age of 763±33 Ma, identical to the timing of the Wudangshan volcanism within error, with few concordant grains of 1.9 and 0.86 Ga. Age spectra for the two river-sand samples are similar to those of the Yangping and Shuangtai Formations, respectively. It thus suggests that the Wudangshan strata are less than 780 Ma, whereas their major detrital zircon populations of 1.0–0.85 Ga and 830–780 Ma are consistent with timing of the Hannan magmatic activities along the northwestern margin of the South China Block. This suggests a Hannan or adjacent area provenance for the Wudangshan strata. The Wudang area is characterized by rift-related igneous events at ~755 and ~680 Ma, respectively, pointing to a tectono- magmatic history different from the Hannan area. It is inferred that the ~755 Ma magmatism is likely to indicate a separation of the South China Block from the supercontinent Rodinia, while the ~680 Ma event suggests a further split between the South Qinling and some unknown continent.     

响应面法优化龙胆苦苷脂质体的复乳法制备工艺

采用复乳法制备脂质体,使用3因素3水平的Box-Behnken响应面设计,以脂质体的包封率、载药量和综合评价为响应值,考察龙胆苦苷药液质量浓度、第一次乳化超声时间及膜材中磷脂与胆固醇的质量比对响应值的影响,并用Design-Expert 7.1.3软件（试用版）进行数据拟合、数学建模和预测分析。优化出的龙胆苦苷脂质体的最佳处方为龙胆苦苷药液质量浓度为2.04 mg/mL、第一次乳化超声时间为7.07 min、脂质体膜材中胆固醇与磷脂质量比为0.45。研究结果表明,在最优处方下龙胆苦苷脂质体形态完整、状态稳定,平均粒径为131 nm,其包封率为52.39%,与预测值的偏差率小于1%。     

新一代SAR 对地观测技术特点与应用拓展

从新一代SAR 对地观测机理及其应用的角度, 对新一代SAR 的技术特征与科学内容、新一代SAR 对地观测领域研究前沿、新一代SAR 研究的重大科学与技术问题和新一代SAR 的未来发展方向等进行了深入的分析和讨论. 我国急需开展该领域的系统研究, 使SAR 研发应用从跟踪走向创新, 提高雷达对地观测科学与技术水平, 服务国家多领域 需求与发展.     

Timing of the Wudangshan, Yaolinghe volcanic sequences and mafic sills in South Qinling: U-Pb zircon geochronology and tectonic implication

The Wudangshan, Yaolinghe volcanic-sedimentary sequences and doleritic-gabbroic sills comprise the largest exposed Precambrian basement in South Qinling. Zircons separated from 5 volcanic-pyroclastic samples of the Wudangshan Group, 2 volcanic samples of the Yaolinghe Group and one sample for the mafic sills were used for U-Pb dating by laser ablation-inductively coupled plasma mass spectrometry （LA-ICPMS）. The results reveal that the Wudangshan volcanic sequence was formed at （755±3） Ma （a weighted mean from the 5 samples, MSWD=0.47）, whereas the Yaolinghe volcanic suite and the mafic sill were crystallized at （685±5） （2 samples, MSWD=0.36） and （679±3） Ma （MSWD=1.6）, respectively, which are equal to each other within analysis errors. These ages are markedly younger than those previously documented for the rocks. The newly obtained ages for the Wudangshan and Yaolinghe Groups are Identical to those of the bottom Liantuo and slightly older than those of the Nantuo Formations, respectively, lower strata of the Nanhua （middle to late Neoproterozoic） stratotype section in eastern Three Gorges, Yangtze creton. A range of inherited magmatic zircons was recognized with ages of 830 to 780 Ma, which are typical of Neoprotzrozoic magmatisms recorded along the margins and interior of the Yangtze craton. Thus, there is Neoproterozoic basement comprising 830-780 Ma igneous suites in South Qinling; the inherited zircons were detrital sediments derived from the northern margin of the Yangtze craton. Accordingly, it is suggested that the South Qinling is a segment of the Yangtze creton before the Qinling Orogeny.     

催化动力学光度法测定痕量锰的研究

本文研究了在ＰＨ４．８的邻苯二甲酸氢钾──氢氧化钠介质中痕量Ｍｎ（Ⅱ）对ＫＩＯ４氧化铬黑Ｔ褪色的新指示反应；其反应的活化能为６０．１８ＫＪ．ｍｏｌ－１，表现速率常数ｋ＝７．３９×１０－３ｍｉｎ－１，半衰期Ｔ１／２为９３．８ｍｍ，该反应为一级反应，由此建立了催化动力学光度法测定痕量锰的新方法。本方法的检出限量为１．４５×１０－１０ｇｍｌ－１，测定范围为０～０．１ｕｂ／２５ｍｌ。对白糖和包菜中锰的测定，结果个人满意。