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21.
1991年淮河流域农村洪涝灾情分析   总被引:11,自引:0,他引:11  
史培军  顾朝林 《地理学报》1992,47(5):385-393
本文从灾害系统的概念出发,分析了1991年淮河流域苏皖地区农村洪水的雨情、水情和灾情,并探讨了这次洪水对农村造成严重灾情的原因。  相似文献   
22.
Windows下静止卫星云图处理软件   总被引:5,自引:1,他引:4  
使用可视化开发工具在微软Windows操作系统下开发了一套针对科研和教学使用的GMS-5静止卫星云图处理软件,它使用方便灵活,基本功能完备,能够完成气象研究中对静止卫星云图处理的基本要求。该软件的主要功能有:云图叠加地图与经纬网格、亮温等值线处理、云图平均、云图数字增强、云图转存为常用格式图像文件等。  相似文献   
23.
工业CT技术在卫星产品检测中的应用   总被引:2,自引:0,他引:2  
卫星产品许多都采用了焊接结构。为了保证其使用的安全可靠性,必须对焊缝进行l00%的无损检测。然而对于一些形状复杂的精密电子束焊件,由于产品尺寸小,加之焊缝周围结构的遮挡,使常规方法的应用受到了限制。工业CT技术具有不受试件材料种类、形状结构及表面状况限制的特点,能给出与试件材料密度及尺寸特性相对应的断层扫描图象,分辨率高,在检测复杂构件方面显示出了优势。本文介绍了卫星产品精密复杂焊接件对无损检测技术的具体要求,研究了卫星产品电子束焊缝的工业CT检测方法,包括设备、对比试样、检测工艺、评定方法等,并通过电磁阀、喷注器、自锁阀、减压器、加注/排放阀、单向阀、气滤、过滤器等具体产品检测实例,描述了工业CT技术在卫星产品检测中的应用。实际应用表明:工业CT是检测航天卫星产品精密复杂结构件焊缝缺陷的理想手段,其成象直观,缺陷的定位、定性和定量结果可靠,完全能满足产品的质量控制要求。目前,累计用工业CT检测卫星产品数批若干件,检测焊缝上千条。剔出有超标缺陷的产品40件,避免了隐患。经过工业CT检测的产品,己在"返回式卫星"、"风云二号"、"东方红三号"、"资源一号"、"中星-22号"等型号卫星中取得了成功应用。  相似文献   
24.
Based on a barotropic inflow-outflow model,we examine the formation of the Kuroshio large meander(LM) using conditional nonlinear optimal perturbation(CNOP) method.Both linear and nonlinear evolutions of such perturbations obtained by this method are investigated.The results show that the nonlinear evolution can result in the Kuroshio transition from a straight to LM path,whereas the linear evolution cannot.This implies that nonlinearity plays an important role in the formation of the Kuroshio LM path.The nonlinearity exists as advection in the evolution equations of the perturbation derived from the barotropic inflow-outflow model,namely the nonlinear advection of the perturbation by the perturbation(NAPP).By examining the role of this nonlinearity,we find that the NAPP tends to move the cyclonic eddy induced by the CNOP-type perturbation westward.Together with the beta effect,this offsets part of the eastward advection caused by the interaction between the perturbation and the background flow.Hence,the eastward movement of the cyclonic eddy is significantly weakened,effectively causing the eddy to develop.The sufficient evolution of this cyclonic eddy leads to the formation of the Kuroshio LM.  相似文献   
25.
21世纪地球科学已经发展成为结合与联系了生物科学、社会科学、计算机科学、物质科学和工程科学等许多学科在内的真正跨学科科学。地球科学面临新的挑战和发展机遇,为了更深入地理解地球及其内部的相互作用,要求地球科学必须应用整体系统性分析方法,探索应用来自所有科学与工程学科的最新知识和技术。美国科学基金会(NSF)地球科学咨询委员会(AC-GEO)针对地球科学面临的新挑战,指导"地球科学远景工作组"(GEO Vision Working Group)制订了地球科学未来发展的新的规划:《地球科学远景(GEOVISION)——通过地球科学揭示未被拆散的地球的复杂性》,强调从整体系统角度来迎接地球科学未来面临的挑战。主要介绍《地球科学远景报告》的主要观点,AC-GEO提出的地球科学面临的3大挑战、5个重大科学问题,以及迎接挑战的3个措施与10个建议。  相似文献   
26.
We have analyzed core MD01-2392, ∼ 360 km east of the Mekong River mouth in the South China Sea (SCS). Over the past 500 ka, planktonic foraminiferal oxygen-isotopic values are consistently lighter than northern SCS and open-ocean records by up to 0.5‰, indicating the influence of run-off from the Mekong River during both glacial and interglacial periods. Carbonate content is higher during interglacials; sedimentation rates were higher during glacials. Increased sedimentation rates since 30 ka imply increased run-off during the last glacial maximum and Holocene Period. Contrary to general experience, in which it is classed as a warm species for temperature estimates, the thermocline-dwelling species Pulleniatina obliquiloculata increased its numbers during glacial periods. This implies an estuarine circulation and even brackish-water caps during glacial periods, reinforcing the sense of strong run-off. In an overall decline of warm water, the thermocline shoaled stepwise, with rapid rises across the glacial terminations. We infer that the southern SCS was opened to an influx of Indian Ocean waters through southern passages at those times of rising sea levels.  相似文献   
27.
塔河油田四区奥陶系碳酸盐岩油藏中的缝合线研究   总被引:1,自引:0,他引:1  
塔里木盆地是我国的重要油气勘探区和产区,但是到目前为止,对塔河油田碳酸盐岩缝洞系统还认识不足,因而严重地影响了塔河油田的勘探开发。通过研究发现,塔河油田奥陶系碳酸盐岩油藏中的裂缝系统非常复杂,主要有两类裂缝:一种是构造裂缝;另一种是缝合线。前人认为前者重要,而忽略后者;而笔者等认为后者比前者更加重要。塔河油田奥陶系碳酸盐岩油藏中的缝合线非常发育,其频度是与石油成藏有一定关系的非构造裂缝所能及。根据缝合线与层面的关系,可以将塔河油田的奥陶系碳酸盐岩油藏中的缝合线分为三种:顺层缝合线、倾斜缝合线和竖直缝合线。这三种缝合线彼此交织成复杂的网络系统,构成了储层内部油气运移的最初级良好通道,同时与裂缝一起构成了有效的油气运移通道和压裂的弱结构面,为油气成藏和后期的开发创造了良好的条件。  相似文献   
28.
Surface rainfall and cloud budgets associated with three heavy rainfall events that occurred over eastern China during the mei-yu season in June 2011 were analyzed using 2D cumulus ensemble model simulation data.Model domain mean rainfall showed three peaks in response to three prescribed ascending motion maxima,primarily through the mean moisture convergence during the torrential rainfall period.Prescribed ascending motion throughout the troposphere produced strong convective rainfall during the first (9 June) and third (17-18 June) rainfall events,whereas strong prescribed ascending motion in the mid and upper troposphere and weak subsidence near the surface generated equally important stratiform and convective rainfall during the second rainfall event (14 June).The analysis of surface rainfall budgets reveals that convective rainfall was associated with atmospheric drying during the first event and moisture convergence during the third event.Both stratiform and convective rainfall responded primarily to moisture convergence during the second event.An analysis of grid data shows that the first and third mean rainfall maxima had smaller horizontal scales of the precipitation system than the second.  相似文献   
29.
Based on a series of international conferences for establishing HFA2 framework, this paper analyzed key issues of frontier of disaster risk science, integrated disaster prevention and mitigation strategies and integrated disaster risk governance. The future direction of disaster risk science was comprehensively discussed according to the widely discussed Post 2015 Hyogo Framework for Action (HFA2). It was proposed to deepen the cognition of the complexity of disaster system in terms of recognizing the complexity of disaster system from the interaction among various elements of the system, recognizing the complexity of climate change risk from the regional characteristics and formation mechanism of the global climate change and recognizing the complexity of the catastrophe risk from the regional development levels and patterns. Furthermore, it was suggested to make integrated disaster risk reduction strategies and countermeasures from the perspective of the complexity of the disaster system, including the establishment of regional integrated disaster risk governance framework to face climate change, the establishment of integrated disaster risk governance system in multi-spatial scale, the establishment of disaster risk governance financial system integrating the insurance, bonds and lottery, the establishment of consilience mode in integrated risk governance considering multi-stakeholder and the establishment of modeling and simulation platform integrated disaster risk information services and disaster risk reduction strategies. Finally, it was pointed out that the assessment of disaster risk levels for different regions in multi spatial scale can provide robust scientific support for integrated disaster risk governance of the world and regions, industries and enterprises so as to improve response to global change and guarantee a global and regional sustainable development.  相似文献   
30.
研究目的】不同页岩岩相的矿物组分、含气性和可压性等的差异,决定不同岩相的开发潜力不同,页岩岩相的划分及评价对找寻页岩气勘探开发甜点具有重要指导意义。【研究方法】基于钻井、岩心和分析测试资料,综合利用地质理论结合硅质矿物-黏土矿物-碳酸盐矿物含量三端元图解,对鄂西宜昌斜坡带上奥陶统五峰组—下志留统龙马溪组下段含气页岩岩相进行划分,结合有机碳含量、含气量、岩心镜下特征等划分优势岩相。优选有机质丰度、硅质矿物含量、黏土矿物含量3项指标与页岩含气量进行相关性分析,建立了五峰组—龙马溪组含气页岩优势岩相的分级标准。【研究结果】研究区优势岩相均为II类优势岩相,II1类(最优)优势岩相为S-2混合硅质页岩相和S-3含黏土硅质页岩相,位于龙马溪组一亚段和五峰组上段,厚6 m;II2类(次优)优势岩相为S硅质页岩相,位于五峰组下段,厚4 m。【结论】宜昌斜坡带和涪陵地区具有相似的岩相垂向演化序列,优势岩相均位于五峰组—龙马溪组一亚段,但同一岩相组合的页岩厚度和品质差异较大,发生在鲁丹阶早期的湘鄂西水下隆起和鲁丹阶晚期的水下隆起是造成宜昌地区优势岩相的厚度和品质均要差于涪陵地区的主要原因。创新点:建立五峰组—龙马溪组含气页岩优势岩相的分级标准,提出龙马溪组一亚段和五峰组是优势岩相发育层位。  相似文献   
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