合成孔径雷达对地观测应用中目标感兴趣区域的自动获取

在简要评述国内外对地观测应用中,利用SAR图像进行目标ROI的自动获取方面的研究成果及存在问题的基础上,提出了一种SAR图像目标ROI自动获取新方案,包括SAR图像自动目标检测方案和SAR图像自动目标鉴别方案并解决其中的关键技术。实测数据的实验结果证明了新方案具有稳健性强、适用性广、自动化程度高、计算量小、工程实现易等特点,说明了该方案对于空间对地观测具有广泛的应用前景。     

基于GPS的“雪龙”船冲击式破冰模式识别研究

"雪龙"号破冰船是我国目前唯一的极地考察船,破冰航行是极地船舶的重要特征之一。以"雪龙"号破冰船的GPS数据为基础,通过建立模型算法识别冲击式破冰这一特殊的航行状态,在整个中国第28次南极考察航次的数据分析中,整体识别率超过86.1%,识别正确率达到98%以上。利用此算法,在中国第27次南极考察航次的破冰识别率也超过85%,识别正确率达到93.5%。雪龙船两个航次实测GPS数据验证了本文算法的可用性,而破冰识别统计结果表明,不同航次的破冰模式具有较大的差异。     

Chalcophile element geochemistry of the Baima layered intrusion, Emeishan Large Igneous Province, SW China: implications for sulfur saturation history and genetic relationship with high-Ti basalts

The Permian Baima mafic layered intrusion, believed to be related to the S-undersaturated Emeishan high-Ti basalts, hosts a giant Fe–Ti-V oxide deposit in the lower part of the intrusion. Uniformly high Cu/Pd (1.9 × 10⁶–6.1 × 10⁴) and low Pd/Zr (<0.1) indicate that the Baima parental magma experienced prior sulfide segregation. Mantle-liked δ³⁴S values and low S/Se values indicate negligible external sulfur addition. Primitive mantle-normalized PGE patterns and MELTS calculations indicate that extensive fractional crystallization (~59 %) of chromite, olivine and pyroxene at depth drove the primitive picritic magma to S saturation. Strong positive correlation between IPGE and PPGE and between PGE and V, Cr and S suggest that magmatic sulfide is the dominant mineral controlling the distribution of PGE in the Baima intrusion. A positive correlation between S and Cr, FeO_T + TiO₂ and V content, together with MELTS calculations, indicate that the parental magma of the Baima intrusion reached a second stage of S saturation in the shallower Baima magma chamber, which was likely triggered by decreasing Fe²⁺ accompanying magnetite precipitation. Primitive mantle-normalized PGE patterns for Baima intrusion rocks display similar trends to high-Ti basalts inside the Panxi area, suggesting that they are comagmatic, and following a similar differentiation trend. However, the lavas erupted before they reached sulfide saturation. The more evolved nature of high-Ti basalts outside the Panxi area indicate that they experienced more extensive pre-eruption fractional crystallization. Further fractional crystallization process led these lavas show more PGE fractionated feature.     

新时期中华民族精神的培育

民族精神是一个民族赖以生存和发展的精神支撑。建设中国特色的社会主义现代化事业是一项前无古人的伟大创举 ,它更加需要一种积极向上的民族精神的支撑。培育新时期的中华民族精神是我们的一项重要任务 ,在培育民族精神的时候应该继承民族文化的优秀传统 ,吸收其他民族文化的优秀成分 ,同时又要使民族精神保持与时俱进 ,不断丰富和发展     

GPS /VRS����ʵʱ���ܹ�������㷨�о�

??????????????????GPS/VRS????????,??????IGS?????????????GPS?????????????????????????GPS/VRS????ο???????VRS?????????????????????????GPS???????вο?????磨SGRSN????????????GPS??????磨SCIGN????????????????????????г?????????????????????????·??????и??????????????????????????????????0.004??10 ^-6??????????100 km?????RTK??λ??????????????????GPS/VRS????????????RTK??λ???????????????     

Comparison among sea surface roughness schemes

1 INTRODUCTIONIt is well known that wind-generated wavestorm surge and atmospheric circulation as impor-tant ocean weather events are closely related tomomentum exchange between sea and atmosphere(Oncley and Dudhia, 1995). For this reason, in thepast 20 years, attention has been directed towardshow to better describe momentum exchange throughsea surface. In general, to precisely determine theexchange, improvement should be made in the as-pects of reasonably depicting the roughness de-pend…     

北斗/GPS抗差移动窗口定权位移探测

蠕变状态下Kalman定位精度通常与观测值方差有极大关系,BDS(BeiDou Navigation Satellite System)/GPS组合观测值方差易受观测值权比精确度的影响。为了提高位移探测精度、缩短初始坐标收敛时间及降低监测成本,本文采用时钟同步双天线BDS/GPS接收机,在构建单频单差组合定位模型基础上,分别对GPS和BDS观测值等价权进行抗差处理,利用引入时间相关遗忘因子的Helmert方差估计,精确确定GPS与BDS观测值权比,最后通过实时更新观测值方差,实现扩展Kalman滤波的逐历元定位。试验结果表明,针对短基线(1km),BDS/GPS抗差精密定权Kalman方法可显著缩短初始坐标收敛时间,位移探测精度可达到亚毫米级,位移收敛速率与移动窗口参数基本成反比关系,适用于具有蠕变特征形变体的监测。     

Distribution and pollution assessment of trace metals in seawater and sediment in Laizhou Bay

Selected trace metals(Pb, Cd, Cu, Hg) and arsenic in seawater and surface sediments of Laizhou Bay were determined, to evaluate their spatial distribution, pollution risk and potential ecological risk. Concentrations of the elements were 0.56–2.07, 0.14–0.38, 12.70–18.40, 0.014–0.094, and 1.13–2.37 μg/L in the seawater and 8.94–32.2, 0.18–0.67, 4.51–30.5, 0.006–0.058, and 5.75–15.3 mg/kg in sediments for Pb, Cd, Cu, Hg and As, respectively. High concentrations of the trace metals and arsenic in seawater and surface sediments were generally observed near the river estuary. The pollution risk result of the elements showed that Cu was the prominent trace metal pollutant in seawater, followed by Hg, Pb, Cd and As. The metal complex pollution index in seawater was at a medium level. The most important trace metal pollutant in sediments was Cd, followed by As, Cu, Pb, and Hg. Our pollution assessment suggests that trace metal pollution in Laizhou Bay sediments was at a low level. The potential ecological risk was also low in surface sediment.     

广东1∶5万厚街圩、小榄镇、容奇镇、太平镇幅区域地质调查项目进展及主要成果

"广东1∶5万厚街圩、小榄镇、容奇镇、太平镇幅区域地质调查"项目区内,第四系浅覆盖区面积占71%。在充分利用前人地质调查研究成果的基础上,综合采用地表路线调查、物探、遥感、钻探和钻孔第四系精细研究等方法开展工作。通过3 a的调查与研究,建立了珠江三角洲晚更新世(始自128 ka)5阶段(MIS5)海洋氧同位素海侵层序及地层格架;根据钻孔沉积物样品磁化率变化进行了地层对比及沉积旋回划分,为珠江三角洲第四纪研究奠定了基础;查明了测区NE、NW向隐伏主干断裂的空间展布及其活动性,为工程建设及防震减灾提供了基础资料;通过花岗岩类锆石SHRIMP U-Pb精确定年,提出了二长花岗岩存在于印支期花岗岩带并形成于晚侏罗世陆壳伸展构造环境的新认识。