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1.
Will.  D Tungs.  L 《地学前缘》1997,4(1):34-42
为预测未来全球的气候变化,必须了解在过去水圈,气圈与生物圈的各自作用以有它们是如何相互影响的。为此,IGBP组织了过去全球变化项目。湖相沉积物保存 与PAGES有关的不同时空尺度的丰富的地球系统历史信息,特别是湖相沉积物包含着可以说明全球抉变化的水圈与生物圈的陆源组分的反应。  相似文献   

2.
国际地圈-生物圈计划(IGBP)是当前地学领域最重要的科学活动之一,其核心项目“古全球变化(PAGES)”的主要目标是研究过去的全球变化问题。而PANASH计划(南北半球古气候计划)是当前PAGES活动的焦点。其主要目标是通过三个PEP(极地—赤道—极地)大断面,建立气候变化的序列和相位关系。文章对PANASH及其三个PEP项目的主要科学目标和科学问题进行介绍,并对它们共同的科学问题进行分析。我国是PEP-Ⅱ断面的重要组成部分,在该方面研究的程度直接关系到整个PEP-Ⅱ的工作。组织好该方面的研究是我们重要的国际科学责任和义务。  相似文献   

3.
国际地圈-生物圈计划是当前地学领域最重要的科学活动之一,其核心项目“古全球变化”的主要目标是研究的全球变化问题。而PANASH计划是当前PAGES活动的焦点。其主要目标是通过三个PEP大断面,建立气候变化的序列和相位关系。文章对PANASH及其三个PEP项目的主要科学目标和科学问题进行介绍,并对它们共同的科学问题进行分析。  相似文献   

4.
过去全球变化(PAGES)是IGBP的核心计划之一。在同国际PAGES计划研究内容对等的前提下,我国的过去全球变化研究既应发挥国内原有工作的传统优势,又应照顾到东亚古环境演变的独特性和填补全球资料空间缺口的需要。根据这一原则,本文对我国相应于PAGES计划的具体研究内容提出了若干建议。  相似文献   

5.
“古全球变迁”计划 (PAGES ;PastGlobalChanges)乃是国际地圈—生物圈研究计划(IGBP ;InternationalGeosphere -BiospherePro gramme)的五项核心计划之一 ,主旨在于透过各国及国际间组织 ,取得并解释有关古气候和古环境方面的纪录 ,以探究环境变迁的原因 ,并评估人为作用在地球的自然系统中的生物圈 ,地圈及大气圈中的角色。为了对全球古气候有深入且全面的认识 ,PAGES乃成立了三个贯通两极与赤道的研究组 ;第一组为美洲区 (PEPI -Pole -Equator -…  相似文献   

6.
生态网络专家会议在西班牙召开由国际地圈生物圈计划(IGBP)、全球陆地观测系统(GTOS)和全球气候观测系统(GCOS)联合召开的“生态网络专家会议”(MeetingofExpertsFromEcologicalNetworks)于1997年6月17...  相似文献   

7.
联合古陆(PANGEA)──全球沉积地质计划的新目标王成善编译(成都理工学院沉积研究所)人类生存在地球,就存在着了解地球的过去、现在和未来发展的强烈欲望。于是,伴随着工业化革命,在19世纪中叶时诞生了地质学中的现实主义原则和理论。随之,在本世纪初期也...  相似文献   

8.
全球沉积岩数据库(简称SEDBA)在UNESCO-IGCP和IUGS支持下,由IGCP269项目设计建成。建立SEDBA的目的是实现对全球沉积岩数据的存储、管理、检索和利用,以促进信息的国际交流和全球地质对比研究的开展。SEDBA可存储各类沉积岩样品的采样地点、构造位置、地质年代、地质特征、结构构造、沉积作用及环境、古地理等宏观信息,以及化学分析、组分及模态分析、碳质及烃类产出特征、重矿物分析、粒度分析、工程及物理参数测定。化石及抱粉分析、流体包裹体测温及各种流体特征、X射线衍射分析等分析测试数据,并附文献库、图件登记文件和采样登记文件。SEDBA系统由26个文件按三个层次构筑而成。目前研制成功的FOXSEDBA和PARADOXSEDBA两套管理软件可在PC系列微机上实现对SEDBA的管理和应用。SEDBA今后的发展方向,将通过国际合作,实现SEDBA与其它有关数据库的联网及通讯,形成一个多功能、综合性的数据库系统,在沉积模型及模拟、盆地分析、岩相古地理、层序地层学、沉积地球化学、能源及矿产资源勘探和开发等课题中开展应用研究,更新和完善SEDBA的结构及功能。  相似文献   

9.
《全球沉积岩数据库》讲座(三)叶健骝,南君亚,杨卫东(中国科学院地球化学研究所贵阳)第三讲全球沉积岩数据库管理系统──FOXSEDBA及其使用方法FOXSEDBA是由IGCP269项目中国工作组根据SEDBA数据结构模型在PC系列微计算机上开发研制的...  相似文献   

10.
Recent Progress on Global Change Research in China   总被引:2,自引:0,他引:2  
RECENTPROGRESSONGLOBALCHANGERESEARCHINCHINAFuCongbin,YeDuzheng(ChinaCommitteeforIGBP,CAST,Beijing100008)RECENTPROGRESSONGLOBA...  相似文献   

11.
Komatiites are mantle-derived ultramafic volcanic rocks. Komatiites have been discovered in several States of India, notably in Karnataka. Studies on the distribution of trace-elements in the komatiites of India are very few. This paper proposes a simple, accurate, precise, rapid, and non-destructive wavelength-dispersive x-ray fluorescence (WDXRF) spectrometric technique for determining Sc, V, Cr, Co, Ni, Cu, Zn, Rb, Sr, Y, Zr, Nb, Ba, Pb, and Th in komatiites, and discusses the accuracy, precision, limits of detection, x-ray spectral-line interferences, inter-element effects, speed, advantages, and limitations of the technique. The accuracy of the technique is excellent (within 3%) for Sc, V, Cr, Co, Ni, Cu, Zn, Rb, Sr, Zr, Nb, Ba, Pb, and Th and very good (within 4%) for Y. The precision is also excellent (within 3%) for Sc, V, Cr, Co, Ni, Cu, Zn, Rb, Sr, Y, Zr, Nb, Ba, Pb, and Th. The limits of detection are: 1 ppm for Sc and V; 2 ppm for Cr, Co, and Ni; 3 ppm for Cu, Zn, Rb, and Sr; 4 ppm for Y and Zr; 6 ppm for Nb; 10 ppm for Ba; 13 ppm for Pb; and 14 ppm for Th. The time taken for determining Sc, V, Cr, Co, Ni, Cu, Zn, Rb, Sr, Y, Zr, Nb, Ba, Pb, and Th in a batch of 24 samples of komatiites, for a replication of four analyses per sample, by one operator, using a manual WDXRF spectrometer, is only 60 hours.  相似文献   

12.
本文拟定了一种以熔融法制备样片,用X射线荧光光谱测定硅酸盐类样品中Si、Fe、Al、Tj、Mn、Ca、Mg、K、Na、P等元素的分析方法。在对不同靶材X光管和分光晶体实验对比的基础上,选择了最佳的测量条件。该法具有快速、准确,测量范围广,检测限低,价格便宜等优点。经过近百个各种类型标样或管理样品的分析对比表明,本法不仅适用于硅酸盐类岩石样品的分析,还适用于铁矿、铝土矿、碳酸盐类岩矿样品以及水泥、耐火材料等样品的分析。  相似文献   

13.
最新的流行病学研究表明,空气中较高浓度的悬浮细颗粒可能对人类的健康有不利的影响。根据该项研究显示,由于心脏病、慢性呼吸问题和肺功能指标恶化而导致死亡率的升高与细尘粒子有关。这些研究结果已经促使欧盟于1999年4月出台了限制空气中二氧化硫、二氧化氮、氧化氮、铅和颗粒物含量的法案(1999/30/EC),对各项指标包括对可吸入PM10颗粒的浓度提出了新的限制性指标。PM10颗粒是指可以通过预分级器分离采集的气体动力学直径小于10μm的细颗粒。目前研究的兴趣重点逐步偏向PM2.5这些更细微颗粒物,PM2.5这种颗粒物对健康有明显的不利影响。在欧盟指令2008/50/EC中,对PM10和PM2.5都提  相似文献   

14.
This paper reports the first results of a study of 11 isotope systems (3He/4He, 40Ar/36Ar, 34S/32S, 65Cu/63Cu, 62Ni/60Ni, 87Sr/86Sr, 143Nd/144Nd, 206–208Pb/204Pb, Hf–Nd, U–Pb, and Re–Os) in the rocks and ores of the Cu–Ni–PGE deposits of the Norilsk ore district. Almost all the results were obtained at the Center of Isotopic Research of the Karpinskii All-Russia Research Institute of Geology. The use of a number of independent genetic isotopic signatures and comprehensive isotopic knowledge provided a methodic basis for the interpretation of approximately 5000 isotopic analyses of various elements. The presence of materials from two sources, crust and mantle, was detected in the composition of the rocks and ores. The contribution of the crustal source is especially significant in the paleofluids (gas–liquid microinclusions) of the ore-forming medium. Crustal solutions were probably a transport medium during ore formation. Air argon is dominant in the ores, which indicates a connection between the paleofluids and the atmosphere. This suggests intense groundwater circulation during the crystallization of ore minerals. The age of the rocks and ores of the Norilsk deposits was determined. The stage of orebody formation is restricted to a narrow age interval of 250 ± 10 Ma. An isotopic criterion was proposed for the ore-bearing potential of mafic intrusions in the Norilsk–Taimyr region. It includes several interrelated isotopic ratios of various elements: He, Ar, S, and others.  相似文献   

15.
Mining induced subsidence can significantly affect mining costs where major surface facilities and natural environment need to be protected. Overburden grout injection is a technology used to control coal mine subsidence by injecting the mine waste material extracted from the coal back into the inter-burden rock during longwall mining. The flowing slurry is here categorised as a nonlinear viscous cohesive (Bingham plastic) fluid. During longwall mining the grout slurry is pumped into the separated beds of the rock mass through a central vertical borehole, which is drilled deep into the inter-burden rock strata above the coal seam. However, a blockage can occur in the injection system when the slurry velocity falls below a certain critical threshold velocity, indicating a material phase change from cohesive-viscous to cohesive-frictional. In situ field injection tests through boreholes have been simulated at a smaller scale at the CSIRO laboratory in Brisbane by pumping the slurry through a radial disk (gap = 4 mm) from its centre. Laboratory experiments indicate a general, nonlinear, cohesive, viscous, frictional model for shear behaviour of the slurry, in which the material shear parameters are functions of the disk radial distance. Complete dimensional and dimensionless analytical solutions have been developed based on an approach related to Bingham–Herschel–Bulkley fluid mechanics. The derived formulae include relations for minimum pump pressure, local pressure and pressure gradient, wall shear stress, volume rate, velocity and velocity gradient. The theoretical results match the experimental measurements. The experiments covered slurries with maximum particle sizes of 0.5 to 2 mm with about 50% being larger than 100 µm. The viscosities at the various solids concentrations were measured with a standard torsion viscometer. This study differs from the previous research in several distinct aspects, namely, consideration of the variable shear parameters rather than fixed values, inclusion of total nonlinear behaviour, and implementation of a friction function to mimic behaviour of the deposited and consolidating stiff slurry, which can cause a significant pressure rise as a result of the increased shear resistance.  相似文献   

16.
本文介绍样品经四硼酸锂熔融制成玻璃小饼。采用Lachance模式和理论a系数来校正元素间的效应,由3080E型X-射线荧光谱仪和DF-350B数据处理系统完成硅酸盐中十三个项目的测定。  相似文献   

17.
岩石密度和超高压岩石折返速率   总被引:1,自引:3,他引:1  
在常温常压条件下对中国大陆科学钻CCSD主孔100-3000米岩心样品进行了密度测量,建立了密度连续剖面,并界定了不同超高压岩石的密度值。通过对比高温高压物性实验资料,岩石密度随着退变程度增强而降低,榴辉岩密度变化序列为3.52g/cm3→3.49g/cm3→3.07g/cm3→2.93g/cm3。超高压长英质岩石密度变化序列为3.00g/cm→2.80g/cm3→2.65g/cm3。上述实验资料是讨论不同折返阶段岩石所受浮力的基础,为研究折返速率大小提供了基本参数。本文通过折返板块运动平衡时,上浮力与粘滞力平衡这一关系式,定量研究了大陆俯冲板块的折返速率,认为密度差产生上浮力从而引起折返,温度对板块折返速率的影响最为显著;密度差大小、折返角度、折返板块大小对折返速率也有直接的影响。定量模拟分析表明,在温度高于850℃时,板块的折返速率可以超过100mm/a;当温度降至700℃时,折返速率则低于1.5mm/a。作者认为在折返早期,温度较高,板块快速折返至60-70km榴辉岩相深度;随着传导散热,温度降低,板块以较慢的速率折返至中下地壳。折返速率的估算表明,浮力是板块折返第一阶段(从>100km深部折返至<40km的中下地壳)的主要驱动力。  相似文献   

18.
The Kuskokwim River at Bethel, Alaska, drains a major mercury-antimony metallogenic province in its upper reaches and tributaries. Bethel (population 4000) is situated on the Kuskokwim floodplain and also draws its water supply from wells located in river-deposited sediment. A boring through overbank and floodplain sediment has provided material to establish a baseline datum for sediment-hosted heavy metals. Mercury (total), arsenic, antimony, and selenium contents were determined; aluminum was also determined and used as normalizing factor. The contents of the heavy metals were relatively constant with depth and do not reflect any potential enrichment from upstream contaminant sources.  相似文献   

19.
滇东南锡、银、铅、锌多金属矿床主要分布在个旧、白牛厂、都龙3个矿区,而滇东南较大的3个花岗岩体又分别出露在3个矿区或附近.花岗岩体均形成于燕山晚期,岩石化学、矿物成分相似,富含锡、银、铅、锌、钨、铜等成矿元素.矿床主金属元素组合与岩体之间的距离由远而近出现由锡、钨、(铍、铌、钽)→锡、钨、(铁)、铜、铟→锡、铅、锌、银、铟、(锑)有规律的变化.花岗岩浆是成矿物质来源和成矿热源.岩浆侵入初期使上覆地层隆起产生背斜(凹陷部位成向斜);同时使地层产生一系列裂隙、压性断层或层间断裂;岩浆侵入晚期,这些断层再次活动,表现为张性,岩浆产生的含矿热液沿由其活动所造成的断裂迁移、充填、交代、沉淀而形成矿床.  相似文献   

20.
Bellechester, Minnesota, is a small community of approximately 155 residents located on the county line between Goodhue and Wabasha counties in southeast Minnesota's karst region. Bellechester is served by a 21-year-old wastewater treatment facility (WWTF) consisting of three waste-stabilization ponds. On 28 April 1992 six sinkholes were discovered to have drained cell 2 of the WWTF resulting in the loss of approximately 8.7×106 1 of partially treated effluent and about 600 m3 of soil into previously undetected subsurface voids of unknown dimensions. In the week following the collapse, approximately 200 water wells located within a 5-km radius of the WWTF were sampled in an after-the-fact, emergency sampling program. Twelve samples with elevated fecal coliform levels, 18 samples with nitrate-nitrogen greater than the 10 mg/1 standard, and no samples with elevated chlorides were found. However, the elevated levels could not be unambiguously attributed to the WWTF collapse. This is the third WWTF to fail by sinkhole collapse in southeast Minnesota since 1974. All three collapsed lagoons have been located in similar geomorphic and stratigraphic settings. However, at least two lagoons have collapsed in the adjacent area in northeast Iowa, and these lagoons are located at different stratigraphic positions. Twenty-two WWTFs constructed in southeast Minnesota's karst region in the last 25 years have been identified as subject to potential sinkhole collapse. An unknown but significant number of manure storage lagoons, flood control structures, etc., have also been constructed in the karst region and are at risk. Public agencies are beginning to develop plans to deal with the risk associated with existing and future waste lagoons in this environment. The critical hydrogeologic parameters that can be used to prioritize the risk of collapse at existing facilities include: (1) the lithology of the first bedrock beneath each lagoon, (2) the thickness of surficial materials between the lagoon and the bedrock surface, (3) the presence and construction of liners (seepage rate), and (4) the proximity to existing sinkholes.  相似文献   

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