楚科奇海与白令海表层沉积中的钙质和硅质微体化石研究   总被引：13，自引：4，他引：13  

陈荣华  孟翊  华棣  王汝建 《海洋地质与第四纪地质》2001,21(4):25-30

通过对北冰洋楚科奇海和令海41个表层沉积样品中的有孔虫、介形类等钙质微体化石和硅藻、放射虫、海绵骨针等硅质微体化石的定量分析，发现表层沉积中浮游有孔虫几乎缺失，这可能与该区表层生产力相对低、碳酸盐溶解作用较强有关，而底栖有孔虫和硅质微体化石的丰度分布则明显受表层沉积物类型、表层初级生物生产力和碳酸盐溶解作用所控制。其中，北冰洋楚科奇海陆架区有孔虫丰度和分异度低，含少量浅水介形类，放射虫在陆架浅水区缺失，但含有较多硅藻和海绵骨针等其它硅质微体化石，反映该区由于海冰、表层海水温度较冷而导致表歧初级生产力相对低。白令海陆坡区底栖有孔虫丰度比较科奇海高一个数量级，底栖有孔虫分异度也相对高，硅藻、放射虫、海绵骨针等硅质微体化石的丰度与钙质化石一样，其丰度比楚科奇海明显高，反映表层初级生产力相对高。根据白令海陆坡区底栖有孔虫和硅质微体化石丰度、底栖有孔虫胶结质壳比值的水深变化，推测该区碳酸盐溶跃层和补偿深度（CCD）相对浅，分别位于水深2000m和3800m处。  相似文献   

Extraction of Lithium from Salt Lake Brine using N523-TBP Mixture System          下载免费PDF全文

时东  李丽娟  李晋峰  姬连敏  宋富根  彭小五  张利诚  张禹泽  李慧芳  宋雪雪  聂锋  曾忠民  刘志启  郭凡 《盐湖研究》2019,27(1)

In this work, problems encountered by tri-butyl phosphate (TBP) in the industrialization of lithium extraction from salt lake brine were discussed in detail. The lithium extraction behavior of N, N-bi-(2-ethylhexyl) acetamide (N523) was investigated, and its defect was analyzed in the view of practical application. The N523-TBP mixture extraction system was proposed to alleviate or avoid the defects that N523 and TBP met when they were used severally. The composition of this mixture extraction system was determined as 20%N523-30%TBP-50% kerosene. The effects of brine acidity, Fe/Li molarity ratio, phase ratio and chloride ion concentration on lithium extraction efficiency were discussed respectively. The operation conditions in single stage extraction were optimized as brine acidity=0.05 mol/L, Fe/Li molarity ratio=1.3 and phase ratio=2. The high concentration of chloride ion in brine was benefit for extraction of lithium. The structure of extracted complex was proposed as (LiFeCl4·nN523·mTBP)·(2-n)N523·(2-m)TBP (m+n=2) by chemical analysis and slope fitting methods. The extraction thermodynamic functions were calculated preliminarily, and the results suggested that the extraction process was an exothermic (ΔH<0) and spontaneous (ΔG<0) reaction, and the degree of disorder increased (ΔS>0) during the extraction process. This work will give some guidance to the lithium industry of Qinghai in both fundamental theory and practical application.  相似文献   

大跨径钢索塔斜拉桥钢箱梁施工测量技术     

孙景领  赵显富  王新志 《东北测绘》2012,(2):196-198

南京长江三桥是我国首座主塔采用钢结构形式的特大型斜拉桥,主梁为正交异性板流线型扁平式钢箱梁。文章介绍了钢箱粱安装的精度要求,以及分步骤建立施工控制网的方法,并详细阐述了不同梁段施工测量的技术和方法,结果表明成桥后的钢箱梁线型符合设计要求。  相似文献   

随机子空间方法在桥塔模态参数识别中的应用   总被引：3，自引：0，他引：3  

常军  张启伟  孙利民 《地震工程与工程振动》2006,26(5):183-187

基于环境振动的结构模态参数识别方法正逐渐成为国内外研究的一大热点。环境振动方法就是仅仅利用结构测试的输出信号进行结构的模态参数识别,随机子空间方法就是其中的一种。随机子空间法是近年来发展起来的一种线性系统辩识方法,可以有效地从环境激励的结构响应中获取模态参数。它属于时域的方法,该方法不需要进行FFT变换,它不仅可以识别结构的频率,而且可以识别结构的阻尼和振型。文章首先介绍了随机子空间的理论,然后用该方法对正在施工中的南京长江三桥的南塔进行模态参数识别,通过与其他方法的识别结果进行比较,证明随机子空间方法不失为一种有效的模态参数识别方法。  相似文献   

浅析意大利新兴工业化地区的兴起   总被引：5，自引：0，他引：5  

李涛 《世界地理研究》1998,(1)

意大利的东北部和中部在二战后迅速崛起,成为新兴工业化地区──称之为“第三意大利”。该区的发展建立在从事工艺型工业的中小型企业密切分工协作的基础上,有着独特的发展模式,本文概括了“第三意大利”的区域经济特征,并对发展原因作了分析。  相似文献   

太平洋环流速度减慢的原因   总被引：7，自引：1，他引：7  

杨学祥 《世界地质》2003,22(4):380-384

对南极气温资料、环南极海冰资料、太平洋海温资料、厄尔尼诺和拉尼娜资料的模拟验证，发现厄尔尼诺事件发生与德雷克海峡海冰减少在时间上有对应关系。南极半岛海冰减少是太平洋环流速度减慢的原因，德雷克海峡的海冰起重要作用。这一综合检验结果给出以日食—厄尔尼诺系数预测厄尔尼诺事件的有效性和准确性。两年周期的太平洋海温振荡使日食与厄尔尼诺之间存在12～24个月的位相差。  相似文献   

澳大利亚夏季大雪与南极海冰三个气候开关   总被引：1，自引：1，他引：1       下载免费PDF全文

杨冬红  杨学祥 《地球物理学进展》2007,22(5):1680-1685

通过对澳大利亚气温资料和环南极海冰资料对比验证,我们发现澳大利亚夏季大雪与对面南极大陆海冰增加在时间上有一一对应关系.我们在2003年就提出,环南极海冰变化是全球气候变化的调节器,德雷克海峡海冰在全球气候变化中起重要作用.2006年澳大利亚夏季大雪验证了这一结论:气候和构造是地球系统中的两个相关因素,它们受天文周期控制.德雷克海峡海冰的减少加快了环南极西风漂流,减慢了南太平洋环流,使东澳大利亚暖流变弱,为南极冷空气袭击澳大利亚东南部的塔斯马尼亚岛创造了条件.特别值得指出的是,潮汐有1.1、2.06、2.2、10、11、22、31、56、62年变化周期,潮汐周期与太阳黑子周期的叠加效应为解释厄尔尼诺、气温、海温、海冰、地磁、地震的11年和22年周期变化提供了理论根据.  相似文献   

Delegating, not returning, to the biosphere: How to use the multi-scalar and ecological properties of cities     

Saskia Sassen  Natan Dotan 《Global Environmental Change》2011,21(3):823-834

Our aim is to theorize the shifting relationship between cities and the biosphere in ways that can incorporate vanguard scientific, technical and social innovations. We specify that the city (a) generates third natures - specific new environments - such as heat islands, that today are destructive of the biosphere, and (b) that the city has systemic properties that correspond to those of the biosphere, but today are mostly flattened out of action through the ruptures that dominate today's articulation between cities and biosphere. That is to say, our specific project agrees with the problematizing of the category “nature,” which pertains to our presence in the biosphere. But we do not take Harvey's more absolute statement that the city itself is nature nor do we confine our analysis only to Latourian natures-cultures. Our analysis is less centered in the work of correcting a false binary, as is the case with both Latour and Harvey, notwithstanding their different objects of study. We focus on the complex in-between space that is the site of both the transactions between city and biosphere, as well as the site of the ruptures that characterize these transactions.  相似文献   

沙埝油田沙7块阜三段高分辨率层序地层分析     

赵红娟  张金亮 《中国海洋大学学报(自然科学版)》2011,41(5):94-99

以高分辨率层序地层学与沉积学等理论方法为指导,综合利用岩心、录井和测井等资料,对沙埝油田沙7块阜三段进行了高分辨率层序地层划分与对比。根据基准面旋回和可容纳空间变化原理,识别出研究区短期和中期2个级次的基准面旋回层序,其中短期旋回层序以向上"变浅"的非对称型和对称型2种基本结构类型为主;在各级次基准面旋回层序识别的基础上,将阜三段划分为3个中期旋回层序和17个短期旋回层序,并应用旋回等时对比技术进行了精细地层对比,建立了沙7块阜三段高分辨率层序地层对比格架,为进一步的储层物性预测及储层结构描述等精细地质研究奠定了基础。  相似文献   

BOOK REVIEWS     

《The Professional geographer》1987,39(2):238-266

Book Reviewed in this article: Women, Work, and Ideology in the Third World . Haleh Afshar, ed. The Birth of the National Park Service. The Founding Years 1913–33 . Horace M. Albright Theatres of Accumulation: Studies in Asian and Latin American Urbanization . Warwick Armstrong and T.G. McGee. New Tools for Social Scientists, Advances and Applications in Research Methods . William D. Berry and Michael S. Lewis -Beck , eds . Uncertain Dimensions: Western Overseas Empires in the Twentieth Century . Raymond F. Betts. Geography of Sugar Cane . Helmut Blume. The Mines of Neptune: Minerals and Metals from the Sea . Elisabeth Mann Borgese. Geographical Dimensions of Energy . F.J. Calzonetti and B.D. Solomon, eds. Statistical Methods for Geographers . W. A. V. Clark and P. L. Hosking. In The Wake of Columbus, Islands and Controversy . John DeVorsey, Jr., and John Parker, eds. Housing, States and Localities . Peter Dickens, Simon Duncan, Mark Goodwin and Fred Gray. Physician Location and Specialty Choice . Richard L. Ernst and Donald E. Yett. Practical Ecology for Geography and Biology: Survey, Mapping, and Data Analysis . D.D. Gilbertson , M. Kent and F.B. Pyatt Large Scale Water Transfers: Emerging Environmental and Social Experiences . Genady N. Golubev and Asit K. Biswas, eds. The Nature of the Environment . Andrew Goudie. Planning for Population Change . W.T.S. Gould and R. Lawton. The Niger and its Neighbors: Environmental History and Hydrobiology. Human Use and Health Hazards of the Major West African Rivers . A.T. Grove, ed. Remote Sensing of Ice and Snow . Dorothy K. Hall and Jaroslav Martinec. Atlas of Antebellum Southern Agriculture . Sam Bowers Hilliard. Galilee Divided; The Israel-Lebanon Frontier, 1916-1984 . Frederic C. Hor . Plains Country Towns . John C. Hudson. Agricultural Geography: A Social and Economic Analysis . Brian W. Ilbery. Industry in the 1980s: Structural Change and Interdependence . U.N. Industrial Development Organization. Crabgrass Frontier: The Suburbanization of the United States . Kenneth T. Jackson. The Industrial Geography of Italy . Russell King. Studies in Linguistic Geography: The Dialects of English in Britain and Ireland . John M. Kirk, Stewart Sanderson, J.D.A. Widdowson, eds. Tourism: A Community Approach . Peter E. Murphy. Cities and Services: The Geography of Collective Consumption . Steven Pinch. An Historical Geography of Europe 1800–1914 . Norman J. G. Pounds. An Introduction to Human Ecology Research on Agricultural Systems in Southeast Asia . A. Terry Rambo and Percy E. Sajise, eds. Discovering Past Landscapes . Michael Reed, ed. Managing the Ocean: Resources, Research, Law . Jacques G. Richardson, ed. Carta fitosociologica de la transecta botanica de la Patagonia Austral . F.A. Roig , Juan Anchorema , Orlando Dollenz , A.M. Faggi and Eduardo Mandez Intermetropolitan Migration in Canada: Changing Determinants over Three Decades . R. Paul Shaw. Chinese Cities—The Growth of the Metropolis since 1949 . Victor F. Sit, ed. Urbanization in the World-Economy . Michael Timberlake, ed. The Al Business: Commercial Uses of Artificial Intelligence . Patrick H. Winston and Karen A. Prendergast, eds.  相似文献