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41.
Olivine exposures at the central peak of Copernicus crater of the Earth's Moon have been confirmed by telescope observations and Clementine spectra data.Using these exposures as training sites,this stu... 相似文献
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新疆东准噶尔萨北富碱花岗岩SHRIMP锆石U-Pb测年及其地质意义 总被引:18,自引:7,他引:18
萨北锡矿赋矿的富碱(A型)花岗岩隶属于新疆东准噶尔地区卡拉麦里富碱花岗岩带,其中的萨北超单元可以划分为细粒钠铁闪石花岗岩、中细粒钠铁闪石花岗岩、中粗粒钠铁闪石花岗岩和斑状钠铁闪石花岗岩等四个单元。本次工作选择萨北超单元中的中细粒钠铁闪石花岗岩和中粗粒钠铁闪石花岗岩进行SHRIMP锆石u-Pb定年,所获得的两个样品加权平均年龄分别为313±2Ma和314±5Ma,谐和年龄分别为310±7Ma和314±10Ma。结合对中亚造山带东准噶尔晚古生代构造环境和萨北富碱花岗岩带花岗岩的地球化学特征,作者认为:该岩体侵位于晚石炭世(约310Ma),为晚古生代后碰撞岩浆活动的产物,与东准噶尔后碰撞深成岩浆活动的两个峰期(330~310Ma和305~280Ma)中的前一个峰期相一致。 相似文献
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海洋产业结构和海域承载力之间存在多种耦合匹配关系,其匹配程度是影响海洋经济健康持续发展的重要因素,而准确地定量化评价这种匹配关系是准确把握海洋产业结构是否失衡的关键环节。文章将海域承载力引入海洋产业结构问题研究中,首先对海洋产业结构水平和海域承载力定量化测算,在此基础上运用基于数列的匹配度计算方法测度辽宁省海域承载状况与海洋产业结构水平的匹配度,探讨海洋产业结构与海域承载力之间的匹配关系。结果表明:辽宁省海域承载力与海洋产业结构水平匹配度数值较高,二者之间存在较匹配的关系。 相似文献
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It has long been acknowledged that there are two types of El Ni(n)o events,i.e.,the eastern Pacific El Ni(n)o (EE) and the central Pacific El Ni(n)o (CE),according to the initial position of the anomalous warm water and its propagation direction.In this paper,the oceanic and atmospheric evolutions and the possible mechanisms of the two types of El Ni(n)o events were examined.It is found that all the El Ni(n)o events,CE or EE,could be attributed to the joint impacts of the eastward advection of warm water from the western Pacific warm pool (WPWP) and the local warming in the equatorial eastern Pacific.Before the occurrence of CE events,WPWP had long been in a state of being anomalous warm,so the strength of eastward advection of warm water was much stronger than that of EE,which played a major role in the formation of CE.While for the EE events,most contribution came from the local warming of the equatorial eastern Pacific.It is further identified that the immediate cause leading to the difference of the two types of El Ni(n)o events was the asynchronous variations of the Southern Oscillation (SO) and the Northern Oscillation (NO) as defined by Chen in 1984.When the transition from the positive phase of the NO (NO+) to NO- was prior to that from SO+ to SO-,there would be eastward propagation of westerly anomalies from the tropical western Pacific induced by NO and hence the growth of warm sea surface temperature anomalies in WPWP and its eastward propagation.This was followed by lagged SO-induced weakening of southeast trade winds and local warming in the equatorial eastern Pacific.These were conducive to the occurrence of the CE.On the contrary,the transition from SO+ to SO- leading the transition of NO would favor the occurrence of EE type events. 相似文献
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47.
In this paper, through data collection and field investigation, the development and utilization status of shallow geothermal energy in Zhoukou urban area was discussed. Based on the analysis of hydrogeological conditions, rock and soil structure characteristics and field test research, the spatial distribution characteristics of rock and soil in the study area were summarized. The study shows that Zhoukou City is located in the alluvial plain of Huanghuai, and the loose deposits of river alluvial genesis range 0-200 m. These loose deposits and groundwater stored in their pores are the main carriers of shallow geothermal energy. In the central part of the Yinghe River in the middle of the study area, the aquifer thickness is within 200 m, the particle size is coarser, the water-bearing degree and recharge capacity is better. On this basis, the paper uses AHP to evaluate the suitability of shallow geothermal energy development and utilization to guide the rational development and utilization of shallow geothermal energy resources. 相似文献
48.
采用常熟台水管仪与垂直摆2009~2015年观测数据,研究了气压、降雨、气温、洞温等因素对地倾斜观测的影响特征。结果表明,降雨对地倾斜观测数据干扰最为显著,表现为NS分量发生南倾,EW分量发生西倾,量级上NS分量受干扰程度比EW分量大,垂直摆受干扰程度比水管仪大;气压变化影响表现为短周期扰动,并导致日值曲线出现短时间畸变;气温及洞温变化影响观测值出现明显的年变规律和年变幅变化,对日观测值影响不明显。 相似文献
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