松辽盆地东南缘层序地层与沉积体系配置及演化--以梨树断陷西北部营城组地层为例

 利用地质和地球物理资料对梨树断陷西北部营城组地层的层序界面进行识别,识别结果表明,营城组地层可划分为2个三级层序,由下至上分别是SQ5和SQ6,对应的3个层序界面分别是SB5、SB6和SB7。各三级层序可进一步细分为低位体系域、湖侵体系域和高位体系域。低位体系域主要由进积准层序组构成,湖侵体系域主要由退积准层序组构成,而高位体系域则以进积或加积式准层序组为主。沉积类型主要有近岸水下扇、扇三角洲、辫状河三角洲和湖泊总计4种相类型,其中辫状河三角洲和湖泊是研究区内最发育的相类型。近岸水下扇和扇三角洲沉积体系在各层序的凹陷边界断层下降盘发育,受构造运动控制明显,常发育在断陷湖盆的陡带;辫状河三角洲沉积体系往往与充沛的长轴物源相配置,常发育在断陷湖盆的缓坡带,指出这种构造与沉积体系的空间配置关系及其演化常受古构造与古地貌的控制。最后指出最有利的储集区位于梨树断陷西北部斜坡带。     

基于空间语义角色的自然语言空间概念提取

根据空间信息的特点,从定义的空间语义角色入手,通过语义角色标注、短语识别以及概念模式匹配等手段,具体分析了自然语言中的空间实体、实体间空间关系以及空间过程的表达与提取方法。     

利用GPS可降水量校正MODIS近红外水汽数据

针对MODIS近红外水汽产品精度不足以及地基GPS技术解算的大气可降水量地理分布不连续的问题,提出一种利用地基GPS可降水量来校正MODIS水汽产品从而得到区域性连续分布的高精度可降水量的方法。利用GAMIT软件和地基GPS数据解算出IGS站点的大气水含量,建立GPS可降水量与MODIS近红外水汽产品的回归分析模型得到最终的校正结果。通过与实测气象站数据对比分析可知,所提方法有效地结合了MODIS和地基GPS两种遥感水汽技术的优点,能够得到高精度、地理分布连续的大气可降水量,研究结果可为实时天气预报、气候监测等工作提供参考。     

Contrasting Sodic and Potassie Glassy Inclusions in Apatite Crystals from an Ijolite

Electron probe analysis of isotropic to weakly birefringentglassy inclusions in apatite crystals within the Usaki ijoliteof western Kenya, indicates that two contrasting compositionsexist. These inclusions are thought to represent samples oforiginal silicate melts. One is rich in K₂O(6 weight per cent),poor in Na₂O(0.3 weight per cent), and oversaturated with respectto silica; and the other is rich in Na₂O(6–14 weight percent), poor in K₂O(0.2 weight per cent), has an antipatheticrelation between Na₂O and CaO (together they usually total 15weight per cent) and is undersaturated with respect to silica.One inclusion shows these two compositions co-existing, apparentlyin an immiscible relationship. Other inclusions show compositionsintermediate between the Na-rich and K-rich types, and theyare interpreted as the result of reduced immiscibility. Thepresence of halides and calcium phosphate is considered to enhancethe immiscibility process. The parental composition, estimatedon a volatile-free basis is: SiO₂ 54.9, Al₂O₃, 27.4, CaO 7.3,Na₂O 3.4, K₂O 6.9, which corresponds to a lime-rich aluminoussyenite.     

我国海洋渔业互助保险发展研究——以舟山市远洋互保为例

海洋渔业是世界上多数沿海国家的一项既传统又古老的生产活动,但是由于海洋渔业的特点和风险的特殊性,造成海洋渔业保险工作很难开展。海洋渔业在我国国民经济中一直占据重要地位,海水产品产业占渔业总比重60%,但是因海洋渔业自身特点,海洋渔业保险的风险相较于一般渔业保险风险更大。改革开放至今,我国的海洋渔业商业保险从鼎盛期萎缩到部分商业保险公司已经退出当地渔业保险市场的程度。因此,就海洋渔业互助保险发展的实际情况来看,国家政策和政府补给应该是其中坚力量,构建符合我国国情的海洋渔业互助保险制度是有效化解现存矛盾的重要手段。文章通过结合具有代表性的我国舟山市远洋渔业互助保险实施中遇到的渔民群体对部分险种的有效了解不足、海洋渔业互助保险业务因保费补贴缺位的原因导致发展规模受限、巨灾风险分散机制缺失,政策扶持力度亟须加强等实际问题,提出我国政府在完善海洋渔业互助保险方面的优化建议即加强专业人才培养、加强我国政策支持的力度和实施政策性再保险。     

基于比值法的多源多时相数据城区变化检测

针对中、低分辨率影像采用常规分类方法进行变化检测无法取得理想效果的问题,本文提出了一种基于比值法的雷达数据和光学影像相结合的城市变化检测方法。该方法综合雷达数据和光学影像的优势,以赣州定南县为研究对象,首先利用比值法分别对两种数据源进行城市变化检测,然后通过分析城区地物目标散射特性,对多个时相变化情况进行真彩色合成,最后结合城市建设规划进行分析验证,从而完成城市实时动态变化检测。试验结果表明,利用多源多时相数据进行比值法可成功地提取出试验区域的变化信息,在城区建筑变化检测中,纹理信息更清晰,准确性更高。     

基于注意力机制LSTM的电离层TEC预测

电离层总电子含量(Total Electron Content,TEC)的监测与预报是空间环境研究的重要内容,对卫星通讯和导航定位等有重要意义.TEC值影响因素较多,很难确定精确物理模型来对其进行预测.本文设计了基于注意力机制的LSTM模型(Att-LSTM),采用过去24小时TEC观测数据对未来TEC进行预测.选择北半球东经100°上,每2.5°纬度选择一个位置,共计36个位置来验证本文提出模型的性能,并与主流的深度学习模型如DNN、RNN、LSTM进行对比实验.取得了如下成果：(1)在选定的36个地区未来2小时单点预测上,基于本文的Att-LSTM模型的TEC预测性能明显优于其他对比模型;(2)讨论了纬度对Att-LSTM预测未来2小时TEC值时性能的影响,发现在北纬0°到60°之间,Att-LSTM预测性能随着纬度的升高而略有降低,在北纬62.5°~87.5°之间,模型预测性能出现扰动,预测效果略差;(3)讨论了磁暴期和磁静期模型的预测性能,发现无论是磁暴期还是磁静期,本文模型预测性能均较好;(4)还讨论了对未来多时点预测效果,实验结果表明,本文所提出的模型对未来2、4个小时的预测拟合度R-Square均超过0.95,预测结果比较可靠,对未来6、8、10个小时预测拟合度最高为0.7934,预测拟合度R-Square下降迅速,预测结果不可靠.

     

太湖水体散射特性及其空间分异

利用Wetlabs公司研制的AC-S和BB9于2006年10月24目至11月2目对太湖水体的散射系数和后向散射系数进行了测量,在此基础上建立了太湖水体散射系数与后向散射系数之间的关系模型。用2种曲线函数模拟,即在蓝光波段使用S形曲线模型,在绿光和红光波段使用逆函数模型,各模型的MAPE和RMSE变化范围分别为0.027-0.156m^-1、0.005-0.050m^-1,模型整体预测精度都较高。研究发现后向散射系数与散射系数的空间分异现象明显,北部梅梁湾、湖心区、西部及西南部水域散射较强,而东太湖、胥口湾等东部水域的散射相对较弱。     

对“关于电离层反射电波频率变化的问题”一文的意见

本刊第22卷第4期发表了龙咸灵教授等的“关于电离层反射电波频率变化的问题”一文,该文认为K.Davies给出的公式（见下节（1）式）不成立,高频多普勒频移数据不能反映出电波反射面运动的状况。本文中将证明文献[2,3]给出的公式在一定的条件下仍然是正确的,多普勒频移有时能反映反射面的运动。     

Recognition of ancient carbonate wind deposits: lessons from a modern analogue, Chrissi Island, Crete

Carbonate aeolian deposits are common along arid to semiarid, wind-exposed, present-day coastlines bordered by productive carbonate ramps. Lithified carbonate dunes (aeolianites) have been described around the world in marine terraces of Quaternary age, but these deposits have seldom been identified in the Pre-Quaternary record. Several authors have suggested that this scarcity reflects that these deposits form and are preserved only during icehouse periods characterized by high-amplitude sea-level changes. Others [e.g. McKee and Ward Carbonate Depositional Environments (1983) , AAPG Memoirs, Vol. 33, pp. 131–170] suggest that the scarcity of aeolianites in the Pre-Quaternary record could reflect the ‘great difficulty in recognising wind blown carbonate deposits and in differentiating between them [aeolianites] and other carbonate sands of nearshore environments’. It has been considered that carbonate shoreface/foreshore deposits are very difficult to discriminate petrographically from backshore deposits. This petrographic study of recent sediments from the shoreface to backshore along the northern coast of Chrissi Island, Crete, confirms that carbonate aeolian sands can be very easily misinterpreted as shoreface deposits. Textural examination of thin sections by image analysis techniques indicates, however, that grain orientation patterns differ between facies. Shoreface deposits exhibit a unimodal distribution of grain orientation (flat rose diagram), whereas backshore deposits show a tendency towards a bimodal distribution with a significant proportion of vertical grains. This observation has been confirmed in Pleistocene aeolianites from Tunisia and Western Australia. Grain verticality thus seems to be a reliable criterion for discriminating wind-lain carbonate bodies from shoreface deposits. Vertical grains in aeolian carbonate deposits could reflect gravity effects (e.g. reorientation of grains because of meteoric water percolation and air pull-up). Laboratory experiments conducted on carbonate sands under the action of percolating waters confirm this hypothesis. This reorganization process is preferentially developed in recently deposited and loosely packed sands resulting from grainfall and/or grainflow. In addition, this suggests that the presence of vertical grain orientation might be an indicator of the frequency and intensity of rainfalls during deposition.