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81.
断陷湖盆缓坡带是油气运移的优势指向区,具备形成岩性地层油气藏的优越条件.本文采用地球物理技术与石油地质分析相结合的方法,分析了T17断块岩性地层油气藏的地质特征与油气展布规律,认为:(1)油气成藏受不整合面、岩性及构造因素综合控制;(2)单个含油砂体的油层在上倾部位受储层超覆尖灭线控制,下倾方向受油水界面控制;(3)多个含油砂体叠和构成了岩性地层油气聚集区带,整个区带油气层纵向上呈阶梯状产出,平面上由构造低部位向构造高部位呈条带状展布.据此,总结该区油气藏的高效勘探开发模式,并应用到该断块的勘探开发实践中,取得了较好的效果. 相似文献
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83.
Zhao-Yong Xu Run-Hai Yang Bin Wang Jin-Ming Zhao Yu-Feng Yao Pei-Zhong Hua Shi-Rong Mei 《地震学报(英文版)》1998,11(6):737-744
A multi-functional high-frequency seismometer, a new instrumental system, is used for recording multi-point strain variations
of rock samples in the process of fracture development. The results indicate that strain in each point appears burst disturbance
synchronously besides a tendency variation before main fracture. The burst disturbance could probably be one of the short-impending
precursors before great earthquake. 相似文献
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85.
为使已获得的中国大陆中上地壳结构更为可靠,本文搜集了很多对浅部结构分辨率较好的短周期面波资料. 与传统面波层析成像反演方法不同,本文在第二步由面波频散得到剪切波速的过程中不再对每个结点进行一维波速模型分别反演,而是直接将所有结点上的区域化频散转换成三维波速结构的线性化约束,实现了直接的三维反演. 检测板测试结果显示该方法可以得到理想的反演结果. 本文得到的波速模型显示,中国大陆中上地壳的速度分布存在明显的横向变化和分区特征. 较低的波速异常很好地勾勒出我国主要的沉积盆地,波速异常在不同深度上的变化在一定程度上反映了各盆地结晶基底的深度. 以东经95deg;为界,特提斯构造域西部具有明显的低速异常,而东部基本没有低速异常. 基于油气资源多存在于沉积层中,而沉积层表现低速异常,我们推测特提斯构造域西部油气前景比东部好. 另外, 由于特提斯构造域西部低速非常明显,这可能也说明了其地壳温度较高. 兴安造山带的低速异常可能也说明了其地壳温度较高. 20 km深度上鄂尔多斯盆地西侧的弱低速带, 很好地勾勒出中国大陆近似沿105deg;经线的强震带的走势. 相似文献
86.
目的 探讨平均血小板体积等参数在急性胰腺炎病程中变化的临床意义及其对治疗效果评估的价值。方法 回顾性分析53例轻症急性胰腺炎(MAP)患者、25例重症急性胰腺炎(SAP)患者和40例健康者(对照组)的临床资料,检测平均血小板体积(MPV)、血小板计数(PLT)、血小板分布宽度(PDW)、白细胞计数(WBC)、C反应蛋白(CRP)及血清钙离子浓度(Ca2+)等指标。比较并分析上述指标在急性胰腺炎病程中及治疗前后的变化。结果 与对照组比较,急性胰腺炎患者入院时MPV显著升高,差异具有统计学意义(P<0.05);与MAP组比较,SAP组入院时MPV明显升高,差异具有统计学意义(P<0.05);SAP组中,MPV在入院后第3天较入院时进一步升高,至入院第5天、第7天逐渐下降;SAP组中,MPV在病程中各时间点与MAP组比较均显著升高,差异有统计学意义(P<0.05);与治疗前比较,急性胰腺炎患者治疗后MPV显著降低,差异有统计学意义(P<0.05)。结论 急性胰腺炎患者平均血小板体积与病情严重程度及治疗效果相关。 相似文献
87.
Potential Impacts of Proposed Chenglingji Hydraulic Project on Wetlands in Dongting Lake 总被引:1,自引:0,他引:1
Water level fluctuation of is an important ecological character of lakes in monsoon climate zone.It is the key driver to seasonal change of the wetlands and associated habitats,which provide vital inhabiting conditions for different species in summer and winter,or,wet season and dry season.Due the hydrologic regime changes in the recent years after the operation of Three Gorges Dam,in 2012,the government of Hunan province proposed Chenglingji Hydraulic Project,aiming at water level control in dry season at Chenglingji,where the outlet of Dongting Lake located.Through different operations on water retreat process,five scenarios on the water level control from 21 m to 24 m were set in the plan.The potential ecological impacts of the project are under enormous public concern.To analyze potential impacts from different scenarios of water level control on the wetlands,this paper studied the topography of Dongting Lake bed and wetlands in dry season,by using Digital Elevation Model(DEM)and 15 images from HJ satellite and 1 image from Landsat TM.The wetlands at water levels of 19 m to 27 m were analyzed.The study revealed that there were 4 terrain steps on Dongting Lake bed from the West Dongting Lake to East Dongting Lake.Water level control at Chenglingji would increase area of open water in East Dongting Lake and Hengling Lake areas,while its effect on South Dongting Lake and West Dongting Lake areas due to higher terrain was weaker.Particularly,the area percentages of South Dongting Lake area did not change with water level fluctuation,due to its 2 elevation steps.The area percentages of various types of the wetlands in Dongting Lake area during the processes of water level rising and retreating were quite different,even in the relatively close water level interval.The retreating area of open water in autumn was larger than that during the spring flooding.The 23 m was the key water level,a turning point of the area change of the wetlands in Dongting Lake area.Areas of open water,mudflat,meadows and their percentages changed significantly at water levels above 23 meters,with increasing of open water area and shrinking of meadow area,their areas would decrease 30 000 ha.As the key habitats for wintering geese,the area of meadows was from near 70 000 ha to 10 000 ha.Among 5 scenarios,the impact of the scenario at 21 m elevation on wetlands was the weakest.However,water level dropping was still postponed than that of natural hydrological process in the scenarios.It resulted in longer inundation of large area of lakebed at elevation of 22-23 m,increasing habitats for aquatic biodiversity but reducing area of the meadows,where is the key habitat for wintering geese.All the other water level control scenarios would cause large area of inundation of lakebed in dry season and dramatic change of wetlands.To maintain the natural wetlands in Dongting Lake area,the Chenglingji Hydraulic Project should be considered in a more cautious way and further researches were needed on the response of aquatic biodiversity and wintering water birds. 相似文献
88.
Self-organizing map (SOM) is used to simulate summer daily precipitation over the Yangtze–Huaihe river basin in Eastern China, including future projections. SOM shows good behaviors in terms of probability distribution of daily rainfall and spatial distribution of rainfall indices, as well as consistency of multi-model simulations. Under RCP4.5 Scenario, daily rainfall at most sites (63%) is projected to shift towards larger values. For the early 21st century (2016–2035), precipitation in the central basin increases, yet decreases occur over the middle reaches of the Yangtze River as well as a part of its southeast area. For the late 21st century (2081–2100), the mean precipitation and extreme indices experience an overall increase except for a few southeast stations. The total precipitation in the lower reaches of the Yangtze River and in its south area is projected to increase from 7% at 1.5 °C global warming to 11% at 2 °C, while the intensity enhancement is more significant in southern and western sites of the domain. A clustering allows to regroup all SOM nodes into four distinct regimes. Such regional synoptic regimes show remarkable stability for future climate. The overall intensification of precipitation in future climate is linked to the occurrence-frequency rise of a wet regime which brings longitudinally closer the South Asia High (eastward extended) and the Western Pacific Subtropical High (westward extended), as well as the reduction of a dry pattern which makes the two atmospheric centers of action move away from each other. 相似文献
89.
In agrometeorology and management of meteorology related natural resources, many traditional methods and indigenous technologies
are still in use or being revived for managing low external inputs sustainable agriculture (LEISA) under conditions of climate
variability. This paper starts with the introduction of an “end-to-end” climate information build up and transfer system in
agrometeorology, in which the use of such methods and technologies must be seen to operate. It then reviews the options that
LEISA farmers have in risk management of agrometeorological and agroclimatological calamities. This is based on the role that
the pertinent meteorological/climatological parameters and phenomena play as limiting factors in agricultural production and
the expectations on their variability. Subsequently, local case studies are given as examples of preparedness strategies to
cope with i). variable water/moisture flows, including mechanical impacts of rain and/or hail, ii). variable temperature and
heat flows, including fires, and iii). fitting cropping periods to the varying seasons, everywhere including related phenomena
as appropriate. The paper ends with a series of important additional considerations without which the indicated strategies
cannot be successful on a larger scale and in the long run. 相似文献
90.
基于NCEP/NCAR提供的1958—2008年逐日再分析资料,对2007/2008年冬季我国雨雪冰冻灾害期间副高指数特征与El Nino/La Nina年平均冬半年副高指数特征以及50a平均冬半年副高指数特征进行对比分析。采用交叉小波和小波相干分析方法,进一步分析了它们之间的相关性和异同性以及对大气环流的影响,揭示了2007/2008年我国南方雨雪冰冻灾害期间副热带高压活动与环流变异特性的一些基本特征,如La Nina事件冬季(尤其是中等强度La Nina事件年份的冬季),副高通常比一般年份副高的平均位置偏北。 相似文献