新疆东准噶尔两类碱性花岗岩及其地质意义   总被引：19，自引：0，他引：19  

刘家远  喻亨祥  吴郭泉 《矿物岩石地球化学通报》1999,(2)

研究证明,东准噶尔境内广泛发育的碱性花岗岩在空间上与深断裂、蛇绿岩及偏碱性的钾长花岗岩类紧密伴生,并可规律地分为卡拉麦里碱性花岗岩带（简称南带）、乌伦古碱性花岗岩带（简称中带）和布尔根碱性花岗岩带（简称北带）。南、中两带碱性花岗岩形成于海西中晚期,图...  相似文献   

强震事件的在线预测技术——伽师-巴楚6.8级强震发生的后思考   总被引：1，自引：0，他引：1  

刘德富康春丽  黎令仪高国英 《地球信息科学学报》2003,5(4):83-87

20 0 3年 2月 2 4日新疆伽师--巴楚 6 .8级破坏性地震的发生 ,再次说明精细预测强震事件的重要性。本文以此次地震为例 ,提出一种预测地震事件的三要素新技术 ,即跟踪地震自激励演变信息预测震级大小、跟踪卫星遥感地表射出长波辐射 OL R信息预测地震危险区域、跟踪自然触发力因素信息预测临震时间。作者认为这种分要素、依序完成在线精细预测的方法是可行的。  相似文献   

火山-侵入杂岩带的成岩-成矿专属性   总被引：8，自引：0，他引：8  

岳书仓  徐晓春 《地学前缘》1999,6(2):305-313

成岩成矿关系问题,特别是成矿作用与岩浆活动的专属性问题,一直是矿床学研究中的重要课题。粤东地区热液脉状锡、钨（多金属）矿床产于中生代花岗质火山岩、次火山岩和侵入岩组成的火山侵入杂岩带中,成岩年龄与成矿年龄一致,但矿床地质、矿床矿物流体包裹体和同位素地球化学没有相对标准来区分这些来源于岩浆作用不同阶段、不同产出状态岩浆岩的成矿物质特征,使得人们对于区内矿床成因的认识不一。文中运用稀土元素地球化学方法,着重探讨和对比了矿床矿石、蚀变岩石及与成矿有关的岩浆岩的稀土元素特征和配分型式,并进一步根据在不同压力条件下Ｃｌ－在熔体和热液间的分配系数实验数据和不同压力条件下热液与相应熔体平衡时的稀土元素分配系数实验结果,分别计算了厚婆坳锡矿床和莲花山钨矿床与矿区有关岩浆岩熔体平衡的热液中的稀土元素浓度并制出配分型式,再与矿床矿石及矿石矿物稀土元素配分型式比较,从而确定成矿与侵入阶段的花岗岩岩浆活动关系密切。区内矿床为岩浆热液矿床。研究结果表明,稀土元素作为热液流体来源的示踪剂能有效地确定火山侵入杂岩带的成岩成矿专属性。  相似文献   

Combined Effects of Molecular Size and Electroendosmotic Flow on the Capillary Electrophoretic Behaviour of Humic Substances     

M. De Nobili  G. Bragato  A. Mori 《洁净——土壤、空气、水》1998,26(3):186-190

The electroendosmotic flow (EOF), generated by the migration of solvated ions near the charged capillary surface, is an important factor in determining the capillary electrophoretic behaviour of humic substances (HS). We investigated the electrophoretic mobilities of HS fractions of reduced molecular-weight polydispersity extracted from peat and from a spodosol either in the presence or after suppression of the EOF. When the EOF was not suppressed, HS migrated to the cathode in spite of their negative charge. Fractionation of HS according to molecular size was achieved in polyacrylamide-coated capillaries filled with 0.05 M tris-phosphate buffer. In uncoated capillaries filled with the same buffer, all fractions had very close mobilities. Addition of polyethylene glycol MW 4000 at concentrations above its entanglement threshold caused the migration times of larger molecules to increase more than those of smaller molecules. The separation was a linear function of molecular size up to 75000 g mol^–1 for peat HS and to 50000 g mol^–1 for HS extracted from the spodosol.  相似文献   

西昆仑麻扎构造混杂岩带中大理岩的遥感识别方法     

陈海云  齐睿  张志 《现代地质》2022,36(1):259-265

为研究如何利用遥感技术对构造混杂岩带进行识别,以西昆仑地区麻扎构造混杂岩带为例,对混杂岩带中的大理岩进行光谱测试以及光谱特征分析,利用实测波谱对研究区ETM+影像进行反演的波谱反演法,建立实测波谱和影像波谱之间的线性关系;辅之增强变换处理方法提取色调信息,扩大不同岩性的灰度差异,突出目标信息并改善图像效果,以提高实测波...  相似文献   

基于MapGIS开发的国土资源电子政务系统     

曲艳红  孙秀平  勾鉴 《东北测绘》2012,(3):156-158

基于GIS技术的国土资源政务信息系统是当前国土资源信息化建设的重要技术手段之一。以国产MapGIS为基础开发平台,针对通化市国土资源局电子政务系统设计中的需求调查与分析、体系结构设计和系统功能设计、系统安全设计等方面进行了较全面地分析,详细介绍了通化市国土资源局电子政务系统的实现与应用。  相似文献   

Rediscovering the anatomy of urban growth: The spatio-temporal evolution of building activity in a Mediterranean city     

《Norsk geografisk tidsskrift. Norwegian journal of geography》2012,66(3):179-180

ABSTRACT

The impact of building cycles on recent expansions of Athens was assessed under the hypothesis that non-linear paths of urban growth result from sequential phases of economic growth and decline. Changes over time in building activity were examined by considering indicators derived from a local-scale analysis of building permits issued by Greek municipalities between 1990 and 2016. Relevant socioeconomic forces shaping spatio-temporal variability in building activity were identified by analyzing contextual indicators through inferential techniques and multivariate analysis. The results showed distinctive responses of real-estate local markets to economic cycles at the local scale in Athens, allowing for identification of short-term and long-term urban dynamics characteristic of expansion and recession waves. The most sensitive indicators to economic cycles in Athens were density of new buildings, average floors per new building, density of building additions, and number of building permits per inhabitant. Infrastructure-driven development, as a result of the 2004 Olympic Games, has produced relevant alterations in short-term patterns in the construction market, resulting in spatially-complex urbanization trends. The author concludes that local-scale indicators derived from building permit data provide insights into progressively complex dynamics of urban growth, with implications for regional planning and the design of sustainable development practices.  相似文献   

Reevaluating the tectonic uplift of western Mount Carmel, Israel, since the middle Pleistocene     

Dov Zviely  Ehud Galili 《Quaternary Research》2009,71(2):239-245

Reevaluation of geological and archaeological evidence from western Mount Carmel constrains its maximal tectonic uplift since the Middle Pleistocene. Tabun Cave, presently 45 m above sea level (asl), revealed human occupation from about 600 ka to 90 ka before present. The 25 m thick archaeological strata at Tabun are composed of laminated fine sand, silt and clays. Moreover, no marine deposits were found in Tabun or nearby caves. Since sea level in the last 600 ka reached a maximal of 5 to 10 m asl, Tabun Cave could not have been uplifted since then by more than 35 to 40 m, that is a maximal average rate of 58 to 67 mm/ka.  相似文献   

一种基于优先级动态调整的802.11e MAC协议     

李方军  曾晓丽  朱西平 《成都信息工程学院学报》2014,29(3):244-249

针对802.11eMAC协议不能良好地处理不同类型业务的节点间的公平性问题,提出一种基于优先级动态调整的802.11eMAC协议(P-MAC)。该协议网络中接入业务根据优先级设置权重系数,通过自适应调整业务权重系数,使不同业务均能公平地接入网络,从而保障业务的公平性问题。仿真结果表明:P-MAC协议相比于802.11eMAC协议,低业务数据流接入信道的机会增大了8%,与此同时,整个网络的平均吞吐量并未有所下降。  相似文献   

Characterization of a cavern conduit system in Vietnam by time series correlation,cross-spectrum and wavelet analyses / Caractérisation du système du conduit d’une grotte au Vietnam par des analyses corrélatoires,spectrales-croisées et en ondelettes de séries temporelles     

《水文科学杂志》2013,58(5)

Abstract

Abstract Time series analyses are applied to characterize the transient flow regimes of the Nam La cavern conduit, northwest Vietnam. The conduit transforms the input signal to an output signal, and the degree of transformation provides information on the nature of the flow system. The input for the analysis is net precipitation and the flow hydrograph at the cave entrance, while the output series is the flow hydrograph at the resurgence. Cross-correlation and cross-spectrum analysis are used to investigate the stationarity and linearity of the input–output transformation of the system, resulting in hydrodynamic properties such as system memory, response time, and mean delay between input and output. It is shown that during high flow periods, the flow in the conduit is pressurized. Consequently, the linear input–output assumption holds only for low flows. To highlight the hydrodynamics of the cavern conduit for the high flow periods, wavelet spectrum and wavelet cross-spectrum analyses are applied.  相似文献