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1.
《水经注》中有关北京地理的科学思想   总被引:1,自引:0,他引:1  
《水经注》是我国古代著名的地理学著作之一,作者郦道元是北魏时期范阳(涿州—北京)人,因此书中对北京附近的水系和地理情况进行了描述。书中称拒马河为巨马水、大石河为圣水、永定河为漯水、清水河为清夷水、温榆河为湿馀水、潮白河为鲍邱水、泃河为泃水,称永定河出山段为清泉河、流经北京城内的什刹海和中南海为高粱河。对家乡附近的地理进行了描述,称房山为大房岭、石景山为梁山,记录了昌平县、密云戍、平谷县等行政区域,记录了羊头埠(羊头岗)、马兰(马栏)、芹城(秦城)、独乐水(独乐河)、良乡、居庸关、盘山等地名。记录了中国最早的首都——涿鹿,记录了中国现代首都蓟城(北京)内曾有蓟丘,说明永定河沟通了古今首都。记录了北京最早的水利工程戾陵堰和车箱渠。  相似文献   

2.
从战略目标、主业定位、理顺事企关系的思路和途径、组织架构、管理制度等方面简述了“江南模式”的主要内容,分析了“江南模式”的特点,即具有实践性又有理论性,既有特殊性又有普适性,既有现实性又有动态性,指出“江南模式”的推行对于广东煤炭地质局的改革和发展,对于地勘单位加强战略研究和主业定位,理顺事企关系,提升管理水平有一定的参考价值。  相似文献   

3.
Since Dow (l972) proposed the concept of oil system atthe AAPG annual meeting in l972, after unremitting effol.tsand progressive perfection, it has become the petroleum systemaccepted by numerous geologists at present. The concept of pe-troleum system was introduced to our country in early l990s(I)ou, l999). In fact, as early as the 1960s, based on the hy-drocarbon exploration and development practice at Songliao ba-sin and Bohai Bay basin, some viewpoints similar to petroleumsystem have be…  相似文献   

4.
外标物质及内标元素的选择是激光剥蚀-电感耦合等离子体质谱(LA-ICP-MS)准确测定元素含量的关键因素之一。文章选用玻璃标准参考物质NIST 610、GSE-1G、BHVO-2G、BCR-2G、ATHO-G、KL2-G和T1-G作为外标,Si或Zr作为内标,对锆石M257中的Ti进行LA-ICP-MS微区原位测定。结果显示,选择Si或Zr作内标,采用BCR-2G、ATHO-G、KL2-G和T1-G作外标时,Ti含量测定值与参考值之间差异均较大,因此它们不适合作外标物质。采用BHVO-2G作外标和Si作内标,NIST 610作外标和Zr作内标,Ti含量测定值与参考值之间的差异均小于4%,因此BHVO-2G和NIST 610可有条件地作为外标物质。选择Si还是Zr作内标,GSE-1G作外标时,Ti含量的测定值与参考值之间的差异均小于3%,说明GSE-1G是较为合适的外标物质。选用GSE-1G作为外标,Si作内标,对5个标准锆石中的Ti含量进行了测定,结果显示,Ti元素在锆石91500中分布不均匀,而在锆石GJ-1、M257、PENGLAI和MUDTANK中分布均匀。在Ti元素分布均匀的GJ-1、M257、PENGLAI和MUDTANK等4个锆石中,由于Ti的含量均小于5μg/g,不适合作为锆石中Ti元素测定用的外标物质,但可作为测定时的质量监控样品。  相似文献   

5.
断层封闭性研究进展   总被引:40,自引:0,他引:40  
对断层封闭性的研究现状进行了总结,概述了断层封闭性理论机理,影响因素和评价方法,对其中存在的一些问题如封闭机理及与有关的评价方法,构造反转与断层封闭的关系以及断层封闭性的三维研究问题进行了讨论。  相似文献   

6.
本文简述地震前兆观测场的要求 ,福建数字地震前兆台网在依据观测场的要求是如何合理分布各观测点。并着重阐述了数字地震前兆台网仪器观测技术系统的组成 ,前兆台网仪器安装过程及仪器安装过程需注意的事项。对福建数字地震前兆台网的安装做了小结。对此次仪器安装过程所遇到的问题如何合理摆放仪器、规范综合布线、传感器密封、避雷地线等做了几点建议。笔者结合多年的维修实际操作经验 ,对地震前兆仪器的设计如何提高仪器标准化、集成化、为维修的方便提出几点思考建议。  相似文献   

7.
The results of analyses of surface waters collected from a variety of locations in west-central Indiana indicate extensive contamination by acidic mine drainage. These samples had pH values as low as 2.1 and total iron concentrations as high as 1200 mg1–1. The speciation of iron, expressed as the ratio [Fe(II)]/[Fe(III)] ranged from 0.08 to 8.27. Measured lead concentrations were as high as 811 mgl–1. In addition, the concentrations of nitrate and sulfate ions were as high as 359 and 624 mgl–1, respectively.  相似文献   

8.
Polished and thin section examinations of samples from Indiana Coal Bed V (Springfield) have shown three sulfides to be present; namely pyrite, marcasite and sphalerite. Pyrite and marcasite are dominant forms whereas sphalerite is very minor. These sulfides appear to have formed in four distinct stages as judged on the basis of mineralogy and mineral texture. Pyrite occurs as framboids throughout the coal seam, as fibrous crystals in two horizons of the coal and in massive form as cleat fillings and cell fillings in fusinite and semi-fusinite. Marcasite occurs in spherical polycrystalline and twinned grains, as polycrystalline overgrowths on framboids, as cementing material for clusters of framboids, as blocky polycrystalline grains and with pyrite as cell fillings in fusinite and semi-fusinite. Sphalerite occurs exclusively as cell fillings in semi-fusinite. The paragenetic sequence indicates fluctuations in the overall coal bed chemistry. Individual sections display evidence of chemical variation on the micro scale.  相似文献   

9.
滇池流域石漠化特征分析   总被引:2,自引:2,他引:0  
张华  王宇  柴金龙 《中国岩溶》2011,30(2):181-186
位于云南省会昆明盆地内的滇池流域是滇中岩溶和石漠化较为发育的地区,石漠化总面积225.56 km2,占流域总面积的7.71%,占岩溶总面积32.69%。石漠化主要分布在望海山、大板桥—呈贡、黑林铺、海口、梁王山、上蒜片区,其中又以北东部的大板桥片区石漠化最为严重。石漠化已造成流域内水土流失加剧、可耕地面积减少、土壤涵养水源能力降低及生态环境恶化等危害。通过地面调查和ETM遥感解译,查清了流域内石漠化的发育分布与碳酸盐岩的岩性及其组合、岩溶作用、地形地貌、气象等自然因素、人为因素和工业污染关系密切。针对石漠化的形成原因,提出了生态修复、农田基本建设、水资源开发利用、农村能源建设、小集镇建设、土地合理利用等治理措施。  相似文献   

10.
《International Geology Review》2012,54(11):1622-1627
Variations in the Ag:Au ratio are discussed, as in halos of ores in the Baley goldfield, across the strike of ore bodies, as well as up-dip. The results bring out spatial zonations in the halos. Attention is called to the usefulness of the ratio in ascertaining migration paths of the hydrothermal solutions, microstructures of the halos, forms of the elements, as well as in prospecting for the ores. — Authors.  相似文献   

11.
洪水灾害分析与评估的综合集成方法   总被引:31,自引:1,他引:30       下载免费PDF全文
从系统论的观点出发,提出了洪水灾害复杂大系统的概念,讨论了该系统的组成特征及其高维性、动态性、复杂性等特征和基于定性与定量的综合集成方法,探讨了洪水灾害系统模拟、预测、评估与决策的综合分析方法。为进一步开展洪水灾害的管理与调控方法的研究奠定了基础,并将有利于促进资源、环境与社会的协调发展。  相似文献   

12.
An X-ray multi-purpose dual-energy computer tomograph has been used to investigate a variety of objects of geological interest such as unconsolidated sediments (sand, silt, clay, mud) and/or metamorphic rock samples. By using an appropriate set of standard materials as well as a proper version of filtered back projection reconstruction algorithms, we have obtained for each studied sample two images, depicting with an error of 2 to 3% densities as well as the effective atomic number. In the case of unconsolidated sediment samples, the computer tomograph has been also used to obtain good quality radiographs, prior to obtaining the tomographic images of the cross-sectional area of interest. Both radiographs and computer axial tomography images had a spatial resolution of 0.4 to 0.5 mm. Digital radiographs as well as tomographic images of unconsolidated sediment samples show with clarity internal features such as grain sizes, laminae thickness and orientation, bioturbations, revoked materials or fragments of wood. Computer tomography analysis of rock samples reveals rheological features in the relationship with metamorphism and deformation, image contrast regarding density and atomic effective number of constituents, as well as significant correlations between physical parameters and internal structures or textures.  相似文献   

13.
油气化探异常评价的研究   总被引:4,自引:1,他引:4  
根据油气化探异常评价的研究方法及其有关问题,指出了选择参数既要具有明确的地质、地化意义,又要符合某种数学原理及最优化准则。据此对异常与背景属性及其确定方法进行了讨论。概述了油气异常判识准则。强调了组构异常及变量之间的相关性或关联信息提取的重要性。  相似文献   

14.
Mahdi  Tew-Fik  Jain  Gaurav  Patel  Shay  Sidhu  Aman Kaur 《Natural Hazards》2019,98(1):119-135
Natural Hazards - Cyclone tracks over the Great Lakes of North America shift, both East–West as well as North–South. The reasons for the shifts are various small-scale as well as...  相似文献   

15.
This contribution is an updated review on sedimentary pyrite and on its role in well-consolidated research topics, such as the biogeochemical cycles and the studies on sediment-hosted ore deposit studies, as well as new frontiers of research, such as astrobiology. Textural and compositional information preserved in sedimentary pyrite from sediment-hosted ore deposits has contributed to elucidate their environment of forzmation. In particular, the content of redox-sensitive elements such as Ni, Co, Mo, and V has implications for defining the syn- and post-sedimentary conditions. In addition, the stable isotope compositions are useful indicators of the pathways of both biogenic and abiogenic pyrite formation. Despite the longstanding research on pyrite and the mechanism of its formation, there are still significant gaps in our knowledge. In this nonexhaustive review, we briefly touch on different current aspects of research on sedimentary pyrite, exemplifying how sedimentary pyrite remains relevant to geoscientists, and becomes more and more relevant in understanding some basic aspects of knowledge, such as the origin of life and the search for extraterrestrial life, as well as aspect of classical applied science, such as the implications for ore deposition.  相似文献   

16.
This paper cites evidence to show that the Organic content of Recent carbonate facies is as readily preserved by entombment as it is in the torrigenous facies and that there is little difference in composition or proportion of organic constituents in terrigenous and some types of carbonate facies. The variations in organic content with grain size follow those for terrigenous facies. Organic constituents in Recent limey sediments are at least as reduced as they are in terrigenous facies. The tendency toward reduction of organic constituents to petroleum bitumens and petroleum is just as obvious and as rapid as in terrigenous. Thus it is quite possible for syngenetic petroleum to be entombed in appropriate carbonate facies.—B. N. Cooper  相似文献   

17.
吉林省四平市山门银矿成矿地质条件分析   总被引:1,自引:0,他引:1  
王福宽 《吉林地质》1994,13(3):9-16
本文对吉林省四平市山门银矿的成矿地质条件从地层、构造、岩浆活动、冷水蚀变等四个方面进行了分析。结果认为,上述四个方面为该矿的成矿物质来源、成矿物质的富集沉淀、导矿和储矿等提供了必备的物理条件和化学条件。  相似文献   

18.
An attempt at flotation of fine grains of zinc carbonate using potassium ethylxanthate as the collector and sulphydryl and copper ions as the activators has been undertaken. Results of the flotation tests have been interpreted in terms of the adsorption of activating agents as well as the grain size effect.  相似文献   

19.
Anthropogenic pollutants were determined in a dated sediment core, collected from a riparian wetland of the Lippe River (Ruhr district, Germany). The historical trend in heavy metals, polycyclic aromatic hydrocarbons, organochlorines, polychlorinated biphenyls and linear alkylbenzenes as well as more recent contaminants such as industrial additives, organotins, synthetic musks, methyltriclosan and some other compounds were determined for the time period between 1930 and 1986. Emission sources, information on technical production and usage, as well as on the individual pollution pathways, with appropriate environmental stability, were considered in the interpretation of the sediment contamination over the past 50 years.Contaminants were analysed and interpreted according to two different criteria: (a) the origin of the main contaminants as related to mining and industrial activities as well as municipal sewage and agricultural effluents and (b) the pollution history. Due to a significant appearance of formerly missing contaminants in sediments deposited since 1970, we suggest classifying contaminants as either common (predating 1970) or modern (postdating 1970).In summary, the study provided a comprehensive reconstruction of the pollution history of the Lippe River system.  相似文献   

20.
This introduction to the themed issue discusses the articulation of protected areas, conservation, and security in issue contributions. Protected areas are presented as localized sites to address global crises, such as anthropogenic climate change and the “war on terror.” When they are sites for securitization and militarization, protected areas articulate state and subject formations through violence. As threat discourses have amplified in recent years, communities once deemed putative eco-destroyers have been interpellated as potential threats in wars on drugs and/or terror. The themed issue reveals that reframing environmental crime as organized crime has significant implications for expanding claims of what counts as legitimate use of force in protected areas policing, as well as potential prosecutions. It is apparent that security for one group may hinge on the insecurity of another group at different historical and political moments. In this special issue we challenge conservation actors as well as those critical of conservation to ask: for whom does conservation provide security, under what circumstances, and at what cost?  相似文献   

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