真实大气望远镜条件下斑点掩模法像复原模拟实验     

邱耀辉  吕瑞宁  钱苹  仇朴章  刘忠 《天文研究与技术》1992,(2)

我们于1989—1990年对一种有效的天文高分辨率像复原方法—斑点掩模法进行了真实大气、望远镜条件下的模拟实验,得到了较好的结果。实验结果表明,取样期间大气统计特性不变和小方差条件的重要性。为满足这一条件,合适的探测器是必须的。  相似文献   

SuperMap GIS在日本的应用与发展     

中野诚 《地理信息世界》2005,3(B08):6-8

简述了SuperMapGIS5年来在日本的发展历史及现状，并展望了未来SuperMap GIS在日本的发展状况。日文版的SuperMap GIS应日本政府、企业和公众需求而产生，在铁路、医疗、教育、设施管理、城市建设等方面发挥越来越重要的作用。在日本地理信息系统领域内，SuperMap经过了多年的探索后正稳步前进。  相似文献   

南渡河放流罗氏沼虾的增殖试验     

钟进  梁立清 《广东海洋大学学报》1994,(1)

１９９０年７月至１９９２年７月，连续三年投罗氏沼虾苗７０万尾放入南渡增殖，回捕率达２４．０５％，最大个体５８８ｇ，抱卵雌虾占捕获量１０％；每年可捕到一定数量体长７～１１ｃｍ、体重１０～３５ｇ的罗氏沼虾。  相似文献   

广东省典型地形土地整理项目中土方量的计算     

李金成  蔺中 《热带地理》2007,27(4):323-326

土方量计算是土地整理规划的重要内容,计算法的科学选取对工程预算和项目实施的准确性具有重要意义。文中在分析比较当前主要土方量计算法的基础上,以国土资源部广东省佛冈县龙山镇土地整理项目和广东省云安县前锋镇土地整理项目为例,分别利用方格网法和梯形断面法对广东省两种典型地形的土方量进行了计算。结果表明,这两种方法在各自适用范围内计算土方量是可行的。  相似文献   

油气田开发中后期的储层三步建模法——以赵凹油田为例     

韩登林  张昌民  李忠  李少华  张尚锋  淡卫东  李莎澜 《地质科技情报》2007,26(5):109-112

三步建模法强调建立等时地层对比格架是储层建模的关键,即首先借助地震、测井和钻井岩心等资料,利用高分辨率层序地层学理论建立精细的等时地层对比格架,继而在格架内以不同层次的旋回层序建立沉积微相模型,从而在沉积微相的约束下建立储层物性模型.三步建模法应用于赵凹油田的结果显示,所建立的模型较好地反映了储层地下特征,经验证效果较好.  相似文献   

鲁西地区沿寒武系/太古宇不整合面滑脱构造的主要特征及形成机制   总被引：12，自引：0，他引：12  

李理  张进江  钟大赉  王先美 《地质科学》2007,42(2):335-352

郯庐断裂带以西的鲁西地区,寒武系/太古宇不整合面改造成为构造滑脱面,滑脱面上发育碎裂岩和动力变质岩。滑脱面上盘的寒武系底部产生强烈的构造变形,褶皱和破碎带发育;滑脱面之下的太古宇构造变形以劈理和裂缝为主,岩石破碎。构造滑动使露头区寒武系底部地层有不同程度的缺失,济阳坳陷南缘则出现地层重复现象。从地层缺失到褶皱产生再到地层重复是滑脱构造逐渐演化的结果。⁴⁰Ar-³⁹Ar、K-Ar、锆石和磷灰石裂变径迹数据分析表明:滑动的主要时期在早白垩世中-晚期(距今130~110Ma)和中始新世(距今43~37Ma)。各种构造指向标志表明滑动的方向以向北、北北西和北北东为主。滑脱构造是低角度的伸展构造,其机制与华北东部晚中生代的构造变革和新生代以来印度—欧亚板块碰撞、太平洋板块俯冲方向和速度的变化密切相关。  相似文献   

Multi-interferogram method for measuring interseismic deformation: Denali Fault, Alaska   总被引：2，自引：0，他引：2  

Juliet Biggs  Tim Wright  Zhong Lu  Barry Parsons 《Geophysical Journal International》2007,170(3):1165-1179

Studies of interseismic strain accumulation are crucial to our understanding of continental deformation, the earthquake cycle and seismic hazard. By mapping small amounts of ground deformation over large spatial areas, InSAR has the potential to produce continental-scale maps of strain accumulation on active faults. However, most InSAR studies to date have focused on areas where the coherence is relatively good (e.g. California, Tibet and Turkey) and most analysis techniques (stacking, small baseline subset algorithm, permanent scatterers, etc.) only include information from pixels which are coherent throughout the time-span of the study. In some areas, such as Alaska, where the deformation rate is small and coherence very variable, it is necessary to include information from pixels which are coherent in some but not all interferograms. We use a three-stage iterative algorithm based on distributed scatterer interferometry. We validate our method using synthetic data created using realistic parameters from a test site on the Denali Fault, Alaska, and present a preliminary result of  10.5 ± 5.0  mm yr⁻¹ for the slip rate on the Denali Fault based on a single track of radar data from ERS1/2.  相似文献   

Changes in glacial lakes and glaciers of post-1986 in the Poiqu River basin, Nyalam, Xizang (Tibet)   总被引：16，自引：0，他引：16  

Xiao-qing Chen  Peng Cui  Yong Li  Zhong Yang  Yong-qing Qi 《Geomorphology》2007,88(3-4):298-311

Glacial lakes and glaciers are sensitive indicators of recent climate change. In the Poiqu River basin of southern Tibet, 60–100 km NW of Mt. Everest, Landsat imagery defines post-1986 changes in the size and distribution of both glacial lakes and glaciers. Total area of glaciers in the 229-km² drainage area has decreased by 20%. The number of glacial lakes with areas in excess of 0.020 km² has increased by 11%, and the total area of glacial lakes has increased by 47%. The areas of typical large glacial lakes of the area (Galongco, Gangxico, and Cirenmaco) have increased by 104, 118, and 156%, respectively, and these increases are confirmed by field investigations.Comparing the 1986 data, the area of glaciers in the basin headwaters has decreased by 46.18 km² to a present total area of 183.12 km², an annual rate of change of 3.30 km²/year. Trends indicate that the total area of glaciers will continue to decrease and that both the numbers and areas of glacial lakes will continue to increase. Accompanying these trends will be an increased risk of debris flows, formed by entrainment of sediment in glacial-outburst floods and in surges from both failure and avalanche- and landslide-induced overtopping of moraine dams. Based on both the local and world-wide history of catastrophes from flows of these origins, disaster mitigation must be planned and appropriate engineering countermeasures put in place as soon as possible.  相似文献   

Petrogenesis of the Pt–Pd mineralized Jinbaoshan ultramafic intrusion in the Permian Emeishan Large Igneous Province,SW China     

Yan Tao  Chusi Li  Ruizhong Hu  Edward M. Ripley  Andao Du  Hong Zhong 《Contributions to Mineralogy and Petrology》2007,153(3):321-337

The Jinbaoshan ultramafic intrusion is a sheet-like body with a thick wehrlite unit in the center and thin pyroxenite units at the margins. PGE are enriched in several disseminated sulfide zones in the intrusion. Olivine from the intrusion has low Fo and depleted Ni contents compared to olivine from coeval Emeishan picrites. Whole rock major and trace element concentrations suggest that the Jinbaoshan wehrlites originally contained <30% trapped liquid. The total amount of sulfide in the rocks exceeds that which could have been dissolved in the trapped liquid. The Jinbaoshan wehrlites are interpreted to represent residual assemblages formed by dissolution of plagioclase by passing magma. No clear evidence of crustal contamination is indicated by S, Nd and Os isotopes. We envision that sulfide saturation occurred at depth due to olivine and chromite crystallization. Immiscible sulfide droplets were transported to the Jinbaoshan conduit where they accumulated and reacted with magma successively passing through the conduit to achieve high PGE concentrations.  相似文献   

A preliminary discussion on the bio-metallogenesis of TI deposits in the low-temperature minerogenetic province of southwestern China     

Zhang Zhong  Zhang BaoGui  Hu Jing  Yao LinBo  Tian YiFu 《中国科学D辑(英文版)》2007,50(3):359-370

Starting with the research status of bio-metallogenesis of TI deposits and their geology, this work deals with the geological background of TI enrichment and mineralization and the mechanism of bio-metallogenesis of TI deposits, as exemplified by TI deposits in the low-temperature minerogenetic province. This research on the bio-metallogenesis of TI deposits is focused on the correlations between bio-enrichment and TI, the enrichment of TI in micro-paleo-animals in rocks and ores, bio-fossil casts in TI-rich ores, the involvement of bio-sulfur in minerogenesis and the enrichment of bio-genetic organic carbon in TI ores. Thallium deposits have experienced two ore-forming stages: syngenetic bio-enrichment and epigenetic hydrothermal reworking (or transformation). Owing to the intense epigenetic hydrothermal reworking, almost no bio-residues remain in syngenetically bio-enriched TI ores, thereby the TI deposits display the characteristics of hydrothermally reoworked deposits. Supported by the National Natural Science Foundation of China (Grant No. 40372047)  相似文献