Fluoride in the Ground Water of Northeastern Ohio     

Robert G. Corbett  Barbara M. Manner 《Ground water》1984,22(1):13-17

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Time patterns of polarization currents generated in measuring the electrical conductivity of rocks     

Josef Bochníček  Marcela Laštovičková  Reviewer A. Janáčková 《Studia Geophysica et Geodaetica》1982,26(4):412-415

amamuu aau m¶rt;a uu mn¶rt;mu n¶rt; nu u mnama, m num , naa, m uau nuau nmu um a mam uu.  相似文献   

Heavy metals in the Tiber river basin     

M. Pettine  T. La Noce  G. Macchi  F.J. Millero 《Marine pollution bulletin》1982,13(9):327-329

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On the disappearance of the imf sector structure effect in the lower atmosphere in 1974–1977     

Jan Laštovička  Reviewer L. Křivský 《Studia Geophysica et Geodaetica》1981,25(2):208-210

1974–1977. aum n mun ma nu mau nam aum n, a¶rt;a anu aum amumu, m, m a¶rt;am u u am, nmu uam. ¶rt;am uuu nuu m uu.  相似文献   

Evidence for the influence of fCH 4 on the crystallinity of disseminated carbon in greenschist facies rocks,Rhode Island,USA     

Robert P. Wintsch  Anne F. O'Connell  Barbara L. Ransom  Mark J. Wiechmann 《Contributions to Mineralogy and Petrology》1981,77(3):207-213

Disseminated carbon has been extracted from 19 samples of arkosic rocks from the chlorite, biotite and garnet zones in the Narragansett basin, and analysed by X-ray diffraction (XRD) and scanning electron microscopy (SEM). XRD of these samples yields only the (002) peak which may be as much as four times wider than the silicon internal standard peak and is always skewed to low angles 2θ. All (002) peaks were digitized and the four moments calculated. The results suggest that width at half-height (W_1/2) provides a poorer estimate of peak shape than coefficients of skewness and kurtosis. The positive correlation of these coefficients with grain size determined by SEM in the range of 0.1–100 μm suggest a direct relationship between peak shape and grain size. No variable measured in this study correlates with metamorphic grade. However, W_1/2, skewness and kurtosis of the (002) diffraction peak of the carbonaceous material in the biotite and garnet zones correlates inversely with modal carbon. This suggests that the volatilization reaction: C+2H₂=CH₄ may be an important step in the mechanism of graphitization. Variable fugacities of H₂ and CH₄ and/or variable permeabilities may be responsible for the non-uniform development of graphite crystallinity in the greenschist facies rocks in Rhode Island.  相似文献   

基于空间数据库的多媒体图形查询信息系统研究——以苏州河环境综合整治为例   总被引：5，自引：2，他引：5  

张立峰  许有鹏  孙亚梅  王腊春  马劲松 《地理研究》2002,21(3):365-372

本文介绍作者自行开发的GIS软件系统———基于空间数据库的多媒体图形查询信息系统的内容、结构和功能 ,以及在环境规划管理方面的应用。阐明了系统可满足决策管理层和公共信息发布层等不同层次的应用需求 ,对环境工程项目的规划管理可作为示范和借鉴。说明本系统除具有一般GIS系统所具有的功能外 ,还把现代多媒体技术和GIS空间数据库技术结合起来 ,实现了在空间数据基础上的多媒体信息查询 ,丰富了GIS中属性数据查询的内容 ,提高了地图的可视性。详细介绍了一种地理信息系统的空间分析方法———包含分析的算法和在本系统中的具体应用———按多边形区域进行空间相关性关系查询。  相似文献   

Spatially smoothed seismicity modeling of seismic hazard in Slovenia     

Janez K. Lapajne  Barbara Sket Motnikar  Blaz Zabukovec  Polona Zupancic 《Journal of Seismology》1997,1(1):73-85

A progress report on the mapping effort for construction of a peak ground acceleration (PGA) map of Slovenia for 475-year return period for rock and firm soil is presented. The methodology is similar to that recently applied in Central and Eastern United States. It is based on historical seismicity spatially smoothed to different length scales. The procedure is described by Frankel (1995). He uses the characteristic earthquake recurrence relationship and in his firt version four different seismicity models. We also use four seismicity models. But instead of characteristic earthquake recurrence, we use the doubly truncated exponential magnitude-frequency relationship; no evidence of characteristic earthquakes in Slovenia has been found yet. Three of our models are similar to Frankel's first three models. Model 1 uses spatially smoothed activity rate based on magnitude 3.7 and above events since 1880. Model 2 deals with spatially smoothed activity rate based on magnitude 5.0 abd above events since 1690. Model 3 smoothes the observed activity over the entire region; it represents a uniform seismicity zone. Frankel skipped this model in his latest version (Frankel et al. 1996). In model 4, we introduce a new approach of calculating seismic activity rate taking into account released seismic energy. The ground motion attenuation model of Pugliese and Sabetta (1989) is used for all models. PGA maps for models 1, 2, 3 and 4 have been calculated, and a weighted mean map derived from them. A map of model 1 has been compared with the corresponding source zone map; the two maps do not differ significantly. A worst-case map derived from all four models has also been produced.  相似文献   

近42年西藏高原雅鲁藏布江中游夏季气候趋势和突变分析   总被引：32，自引：10，他引：32  

周顺武  假拉  杜军 《高原气象》2001,20(1):71-75

根据1957－1998年雅鲁藏布江中游拉萨、日喀则、泽当、江孜4个站6－8月的平均气温、降水资料，通过线性趋势估计和多项式函数拟合等方法分析了雅鲁藏布江中游地区夏季气候长期趋势变化和周期变化，并利用滑动T检验等方法讨论了突变的问题。结果表明：在过去42a里，该流域夏季气温有明显的上升趋势，1980年突变增暖非常明显；而夏季降水呈下降趋势，60年代中后期至80年代末降水普遍偏少，90年代降水出现回升势头。气温、降水的主要周期集中在高频波段，显著周期为2．8－3．5a。  相似文献   

气候变化对滦河流域水资源影响的水文模式模拟(Ⅰ)降水径流模式系统（PRMS）介绍及其在滦河流域的移植   总被引：1，自引：4，他引：1  

范广洲  吕世华  程国栋 《高原气象》2001,20(2):173-179

简单介绍了引进美国地质勘查中心发展的降水径流模式系统（PRMS）。认为PRMS模式具有多种模拟功能，包含的物理过程也较全面，是当前世界上较好的水文学模式。将PRMS模式系统移植到滦河流域，并对其模拟能力进行了初步检验。结果表明，模式系统在我国滦河流域的移植比较成功，而且能够较真实地再现滦河流域河川径流量及水资源其它分量的年际及季节变化，也可以用于研究气候变化对滦河流域水资源的影响。  相似文献   

A comparison of methods for detection of phosphate limitation in microalgae   总被引：6，自引：0，他引：6  

John Beardall  Tom Berman  Phil Heraud  Medina Omo Kadiri  Brett R. Light  Graeme Patterson  Simon Roberts  Barbara Sulzberger  Emel Sahan  Urs Uehlinger  Bayden Wood 《Aquatic Sciences - Research Across Boundaries》2001,63(1):107-121

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