抓住机遇加速中国空间信息基础设施建设   总被引：1，自引：1，他引：0  

孙小系 《地球信息科学学报》1999,1(1):33-35

本文结合我国的实际,阐述了中国空间信息基础设施(NSII)的内涵,重点讨论了国家空间数据基础设施在NSII建设与发展中的地位与作用,进而提出要抓住机遇,发展我国NSII的思路。  相似文献   

秦岭造山带核部新元古代碰撞变形及其时代--强变形同碰撞花岗岩与弱变形脉体锆石SHRIMP年龄限定   总被引：34，自引：5，他引：34       下载免费PDF全文

王涛  张宗清  王晓霞  王彦斌  张成立 《地质学报》2005,79(2):220-231

已有的研究表明,主要形成于显生宙的秦岭造山带发生过新元古代碰撞造山作用,但确切的碰撞时间尚需研究。综合物质组成、S→I→A型花岗岩演化、强烈的变形改造、区域变质作用和地质演化等多方面的证据,进一步论证了秦岭造山带核部以牛角山岩体为代表的片麻状过铝质S型花岗岩体为同碰撞岩体;其中,牛角山岩体可能为同碰撞早期岩体。该岩体的15个锆石SHRIMP测年点给出2 0 6 Pb/ 2 38U加权平均年龄为95 5±13Ma。该年龄可代表陆壳下冲深埋、碰撞增厚的时间。在同一地点侵入于岩体中的弱变形花岗岩脉的锆石SHRIMP年龄为92 9±2 5 Ma,从而证明,该片麻状花岗岩体记录的同碰撞变形主要发生于95 5～92 9Ma。这为确定新元古代同碰撞造山作用及其时代提供了有利证据。该碰撞时间滞后于全球格林威尔碰撞造山的时间(130 0～10 0 0 Ma) ,与华南陆块汇聚时间大致相同。根据花岗岩演化特点推测,该事件可能是华北南缘或扬子地块北缘的一次小陆块汇聚增生。  相似文献   

Monthly and seasonal numerical forecasts by using the anomaly ocean-atmosphere coupled filtered model   总被引：1，自引：0，他引：1  

Chao Jiping  WangXiaoxi  Chen Yingyi  Wang Lizhi 《大气科学进展》1986,3(2):139-149

Case experiments of monthly predictions of eight winter months during 1976－1977 and 1982－1983 El Nino events are performed by using a three-layer anomalous filtered model (AFM), in which transient Rossby waves are filtered. The results show that this model predicts successfully the large-scale patterns of the monthly mean surface temperature anomalies. The correlation coefficients between observations and predic-tions are basically higher than those of persistence predictions. By comparison with the anomalous general circulation model (AGCM) the AFM gives almost the identical results, but the computation time required for running the AFM is nearly 100 times less than that required for running the AGCM. It is also shown that the results of the three-layer model are better than those of the one-layer model. In the meanwhile, four seasonal forecasts are also earned out by using the same model. It seems that the AFM possesses potential ability in predicting large-scale circulation anomalies.On the basis of the works done during the last decade and of the results in this paper, the predicting ability of the AFM is summed up in the last section.  相似文献   

雪宝顶流域黄龙“8·8”地震后短期内主要水环境变化特征     

赵晓夏  李琼芳  董发勤  代群威  宋娜  董鹏举  崔杰  罗尧东  张强  Xin Zhang  O''Driscoll Mike 《中国岩溶》2021,40(1):77-87

富含Ca2+ 和HCO3-的水体是黄龙钙华地貌得以持续沉积的首要条件。为明确2017年九寨沟“8·8”地震是否对黄龙脆弱钙华体产生影响并进而导致水环境的改变,于2017年10月和2018年8月对黄龙3个主要监测点进行了水样采集和水质参数检测。通过主成分分析震前的多次水质检测结果,得到影响黄龙水化学的主要参数,并与震后的水化学参数进行对比分析,发现:2016年（震前）水质参数显示pH、总磷、总氮对黄龙水质起主要贡献作用,地震后水体的pH、Ca2+ 和HCO3-含量上升,而总磷含量则下降较多,表明地震对黄龙钙华体内部结构产生了影响,导致上升泉（转花泉）中的Ca2+ 和HCO3- 含量增加,并影响了pH,而震后水体中的总磷含量减少,这可能与游客数量大幅度减少有关;“8·8”地震对黄龙钙华沉积区水环境造成了影响,并有利于钙华沉积。   相似文献   

鄂尔多斯盆地纳岭沟地区含铀砂岩中含钛类矿物蚀变特征及与铀赋存关系新认识          下载免费PDF全文

陈路路  陈印  郭虎  冯晓曦  李建国  汤超  赵华雷 《中国地质》2018,45(2):408-409

正1研究目的(Objective)纳岭沟地区位于鄂尔多斯盆地东北部,自开展砂岩型铀矿地质调查与研究工作以来,在含铀砂岩中发现有大量含钛矿物,且部分含钛矿物周边总存在铀矿物。其具体哪些含钛矿物,具有怎样蚀变特征,以及与铀(矿物)具体的赋存关系等尚未明确。通过查明研究区含铀砂岩中钛铁矿等含钛矿物的  相似文献   

Studies on the regional feature of organic carbon in sediments off the Huanghe River Estuary waters   总被引：2，自引：1，他引：1  

YUAN Huamao  LIU Zhigang  SONG Jinming  L&#; Xiaoxi  LI Xuegang  LI Ning  ZHAN Tianrong 《海洋学报(英文版)》2004,23(1):129-134

Organic carbon (OC) in definitely small area sediments(according to marine dimension)offthe Huanghe River Estuary is investigated in order to evaluate the feature of regional difference of physical and chemical properties in marginal sea sediments.The distributions of OC in sediments with natural grain size and the relationship with the pH,Eh,Es and Fe^3 /Fe^2 are discussed.In addition,OC decomposition rates in surfacial/subsurfacial sediments are estimated.OC concentrations range from 0.26% to 1.8%(wt)in the study area. Significant differences in OC content and in horizontal distribution as well as various trends in surfacial/subsurfacial sediments exhibit the feature of regional difference remarkably in marginal sea sediments. The complicated distribution of OC in surface sediments is due to the influence of bacterial activity and abundance, bioturbation of benthos and physical disturbance. The OC decomposition rate constant in surfacial/subsurfacial sediments ranges from 0.009 7 to 0.076 a^-1 and the relatively high values may be mainly related to bacteria that are mainly responsible for OC mineralization;meio-and macrofauna affect OC degradation both directly, through feeding on it, and indirectly through bioturbation and at the same time coarse sediments are also disadvantageous to OC preservation.In almost all the middle and bottom sediments the contents of OC decrease with the increase of deposition depth, which indicates that mineralization of OC in the middle and bottom sediments has occurred via processes like SO4^2- reduction and Fe-oxide reduction.  相似文献   

杭州湾沿海地区地面沉降时序InSAR监测与分析     

韩鹏  杨晓霞  白林  孙奇石 《海洋学报(英文版)》2017,36(7):110-118

Time-series InSAR analysis(e.g., permanent scatterers(PSInSAR)) has been proven as an effective technology in monitoring ground deformation over urban areas. However, it is a big challenge to apply this technology in coastal regions due to the lack of man-made targets. An distributed scatterers interferometric synthetic aperture radar(DSInSAR) is developed to solve the problem of insufficient samples and low reliability in monitoring coastal lowland subsidence, by applying a spatially adaptive filter and an eigendecomposition algorithm to estimating the optimal phase of statistically homogeneous distributed scatterers(DSs). Twenty-four scenes of COSMO-Sky Med images acquired between 2013 and 2015 are used to retrieve the land subsidence over the Shangyu District on south coast of the Hangzhou Bay, Zhejiang Province, China. The spatial pattern of the land subsidence obtained by the PS-InSAR and the DSInSAR coincides with each other, but the density of the DSs is three point five times higher than the permanent scatterers(PSs). Validated by precise levelling data over the same period, the DSInSAR method achieves an accuracy of ±5.0 mm/a which is superior to the PS-InSAR with±5.5 mm/a. The land subsidence in the Shangyu District is mainly distributed in the urban areas, industrial towns and land reclamation zones, with a maximum subsidence rate –30.2 mm/a. The analysis of geological data, field investigation and historical reclamation data indicates that human activities and natural compaction of reclamation material are major causes of the detected land subsidence. The results demonstrate that the DSInSAR method has a great potential in monitoring the coastal lowland subsidence and can be used to further investigate subsidence-related environmental issues in coastal regions.  相似文献   

滇池水域双酚A的环境多介质迁移和归趋模拟     

陈蓉  刘华英  黄斌  杨小霞  李晓曼  孙雯雯  潘学军 《湖泊科学》2015,27(6):1093-1100

以双酚A为研究对象,利用四级多介质逸度模型模拟非稳态非平衡条件下1991-2011年间双酚A在滇池水域水相、表层沉积物相和中层沉积物相中的浓度分布、相间的迁移通量,确定主要迁移过程;结合实测数据,对模型进行可靠性验证;并对常数之外的12个模型参数进行灵敏度分析.结果表明:入滇总量98%的双酚A主要通过水体降解去除,滇池出水去除量和水体残留量共约占1%,余下部分进入沉积物相;沉积物相是残留双酚A最主要的汇,其中,表层沉积物相中双酚A浓度最高,3相中浓度变化趋势受外界输入影响较大;水相→表层沉积物相的迁移为双酚A在滇池的主要迁移过程,其次为表层沉积物相→中层沉积物相;双酚A在水中的降解速率、有机碳分配系数,各环境相中有机碳含量、固相体积比等参数灵敏度较高,对模型的影响较为显著;模型计算浓度与实测浓度吻合较好,表明建立的四级多介质逸度模型适用于滇池水域双酚A环境多介质迁移和归趋模拟.  相似文献   

基于网格模型的导航道路图渐进式化简方法     

郭庆胜  刘洋  李萌  程晓茜  何捷  王慧慧  魏智威 《测绘学报》2019,48(11):1357-1368

针对将导航数据精度降低时的道路图形综合转换为基于网格模型的线图形化简问题,提出了一种基于网格模型的导航道路数据渐进式协同图形综合方法。该方法能保证综合后的单条道路和道路网都与原始高精度数据保持空间方向关系相似。在数据处理过程中,用导航需求来约束道路的渐进式图形简化,并对道路形状和道路交叉处的空间方向关系进行维护,顾及了导航中道路的可视化效果。已用实际生产中的导航数据进行了验证,证明了本文方法是有效且实用的。  相似文献   

S-100产品数据融合处理方法          下载免费PDF全文

洛佳男  万晓霞  段晶 《海洋测绘》2018,(3):52-56

基于S-100的产品规范为各类用途的海上产品和服务提供了生产和应用标准。然而,S-100产品规范在开发编制过程中未充分考虑产品之间的互操作问题,会导致终端应用在"S模式"下处理S-100数据时出现要素和图示的混乱。依据IHO互操作目录规则,从基于航行用途的产品预置模式和融合等级两方面,说明S-100产品数据的融合处理方法,为互操作问题的解决提供思路。  相似文献