涡北井田环境水文地质特征研究   总被引：3，自引：0，他引：3  

张平松  黄芳友等 《中国煤田地质》2002,14(4):44-46,49

以涡北井田勘探阶段的地表水，地下水采样分析资料为基础，利用综合水质指数评价方法对该井田各含水层的水环境质量现状作出评价，获得了各含水层水环境质量等级分级结果。并就井田开发后对水环境的质和量的影响进行了预测分析，指出矿井开发必须注重整个矿区水资源的合理利用与管理。  相似文献   

辽西地区侵入岩与内生金属成矿     

蔡发田  李祥才  毛展新 《矿产与地质》2002,16(3):155-159

通过对辽西地区侵入岩的分布、形成时代和地质特征、侵入岩成因、岩石组合及与内生金属矿产的关系的分析 ,总结出成矿作用和成矿规律 ,提出找矿方向  相似文献   

利用钾长石尾矿制备矿物聚合材料的实验研究   总被引：32，自引：1，他引：32  

马鸿文  凌发科等 《地球科学》2002,27(5):576-583

以福建沙县田口钾长石尾矿粉体为主要原料，以煅烧高岭石作配料，硅酸钠作结构模板剂，氢氧化钠作激活剂，进行了制备矿物聚合材料的实验研究，实验样品静置固化7－28d，其抗压强度高达19.4-24.9MPa。耐酸性，耐碱性指标均优于相似建材的国家标准。在配料组成中，控制高岭石用量为20％，适当提高硅酸钠的用量和固／液化，有利于提高制品的力学性能。实验表明，材料抗中度随固化时间的延长而叶抛物线式发展，矿物聚合材料的形成过程为：铝硅酸盐固体组分的溶解络合，分散迁移，浓缩聚合，脱水硬化。由铝硅酸盐凝胶相固化而在的基体相，其化学组成与沸石相近，微观结构极可能与蛋白质类似，物理形态上呈三维网状结构，将未溶解的晶质颗粒胶结为坚硬块体，是矿物聚合材料获得良好力学性能的结构基础。  相似文献   

沙区植物生态位构建的数学模型及其应用研究   总被引：21，自引：0，他引：21  

李自珍  惠苍  徐中民  刘发明 《冰川冻土》2002,24(4):387-392

生态位构建理论是对生态位研究的新进展.以沙区植物梭梭为研究对象,从进化生态学角度探讨了沙区植物生态位构建机理,扩展了生态位构建的概念,建立了沙区植物种生态位的n维"超体积"构建模式、构建作用的动力学模型及适宜度计测公式.实例分析表明:梭梭的生态位构建作用主要表现在干旱环境的适应性特征上,它能改变和营建局部环境,其多枝的形态结构与叶面生理代谢特征,能有效地截留降水、富集养分在根部土壤中发育为肥岛.计算结果显示,在种植密度梯度上,随着营林密度的减少,其构建动力和适宜度呈上升趋势,试验条件下密度为518株*hm-2时具有最大的构建动力和最高适宜度值,这为梭梭人工林营建提供了定量依据.  相似文献   

渤中坳陷上第三系三角洲的发现、沉积特征及其油气勘探意义   总被引：20，自引：1，他引：20  

徐长贵  姜培海  武法东  杨波  厉大亮 《沉积学报》2002,20(4):588-594

长期以来,受勘探程度的影响,渤海湾盆地渤海海域上第三系一直都被认为是河流相沉积,缺乏良好的盖层,勘探风险较大,这一认识束缚了渤海海域上第三系的油气勘探。随着近年来勘探程度的增强,认识到渤海海域渤中坳陷是渤海湾盆地晚第三纪的主要汇水区之一,在渤中坳陷上第三系发现了湖相沉积及湖泊内的重要储集体-三角洲沉积。本文从构造演化、微体古生物、沉积构造、地球物理等方面阐述了渤中坳陷湖相沉积及三角洲沉积存在的地质证据,并将该区上第三系的三角洲划分为两种类型即湖泊正常三角洲和辫状三角洲,并对其沉积特征进行了精细描述,总结了其形成条件和分布规律。渤中坳陷三角洲的发现具有重要的油气勘探意义,上第三系三角洲发育区将是本区今后上第三系勘探的主战场  相似文献   

An Inter-Laboratory Assessment of the Thorium Isotopic Composition of Synthetic and Rock Reference Materials   总被引：2，自引：0，他引：2  

Kenneth W.W. Sims  James B. Gill  Anthony Dosseto  Dirk L. Hoffmann  Craig C. Lundstrom  Ross W. Williams  Lary Ball  Darren Tollstrup  Simon Turner  Julie Prytulak  Justin J.G. Glessner  J.J. Standish  Tim Elliott 《Geostandards and Geoanalytical Research》2008,32(1):65-91

We present a concerted international effort to cross-calibrate five synthetic Th isotope reference materials (UCSC Th "A", OU Th "U", WUN, IRMM-35 and IRMM-36), and six rock reference materials (UCSC TML, Icelandic ATHO, USGS BCR-2, USGS W-2, USGS BHVO-2, LV18) using multi-collector inductively coupled plasma-mass spectrometry (MC-ICP-MS). We then compare our new values with a compilation of literature mass spectrometric data for these reference materials and derive recommended "consensus"²³⁰Th/²³²Th values for each. We also present isotope dilution U and Th concentration data for four rock reference materials (UCSC TML, Icelandic ATHO, USGS BCR-2, USGS W-2).  相似文献   

The complete set of ASCA X-ray observations of non-magnetic cataclysmic variables   总被引：1，自引：0，他引：1  

Darren S. Baskill  Peter J. Wheatley  Julian P. Osborne 《Monthly notices of the Royal Astronomical Society》2005,357(2):626-644

We present the complete set of 34 ASCA observations of non-magnetic cataclysmic variables. Timing analysis reveals large X-ray flux variations in dwarf novae in outburst (Z Cam, SS Cyg and SU UMa) and orbital modulation in high inclination systems (including OY Car, HT Cas, U Gem, T Leo). We also found episodes of unusually low accretion rate during quiescence (VW Hyi and SS Cyg). Spectral analysis reveals broad temperature distributions in individual systems, with emission weighted to lower temperatures in dwarf novae in outburst. Absorption in excess of interstellar values is required in dwarf novae in outburst, but not in quiescence. We also find evidence for subsolar abundances and X-ray reflection in the brightest systems.
LS Peg, V426 Oph and EI UMa have X-ray spectra that are distinct from the rest of the sample and all three exhibit candidate X-ray periodicities. We argue that they should be reclassified as intermediate polars.
In the case of V345 Pav we found that the X-ray source had been previously misidentified.  相似文献   

The DEEP2 galaxy redshift survey: evolution of the colour–density relation at  0.4 < z < 1.35      

Michael C. Cooper  Jeffrey A. Newman †  Alison L. Coil †  Darren J. Croton  Brian F. Gerke  Renbin Yan  Marc Davis  S. M. Faber  Puragra Guhathakurta  David C. Koo  Benjamin J. Weiner  Christopher N. A. Willmer ‡ 《Monthly notices of the Royal Astronomical Society》2007,376(4):1445-1459

Using a sample of 19 464 galaxies drawn from the DEEP2 Galaxy Redshift Survey, we study the relationship between galaxy colour and environment at  0.4 < z < 1.35  . We find that the fraction of galaxies on the red sequence depends strongly on local environment out to   z > 1  , being larger in regions of greater galaxy density. At all epochs probed, we also find a small population of red, morphologically early-type galaxies residing in regions of low measured overdensity. The observed correlations between the red fraction and local overdensity are highly significant, with the trend at   z > 1  detected at a greater than 5σ level. Over the entire redshift regime studied, we find that the colour–density relation evolves continuously, with red galaxies more strongly favouring overdense regions at low z relative to their red-sequence counterparts at high redshift. At   z ≳ 1.3  , the red fraction only weakly correlates with overdensity, implying that any colour dependence to the clustering of  ∼ L *  galaxies at that epoch must be small. Our findings add weight to existing evidence that the build-up of galaxies on the red sequence has occurred preferentially in overdense environments (i.e. galaxy groups) at   z ≲ 1.5  . Furthermore, we identify the epoch  ( z ∼ 2)  at which typical  ∼ L *  galaxies began quenching and moved on to the red sequence in significant number. The strength of the observed evolutionary trends at  0 < z < 1.35  suggests that the correlations observed locally, such as the morphology–density and colour–density relations, are the result of environment-driven mechanisms (i.e. 'nurture') and do not appear to have been imprinted (by 'nature') upon the galaxy population during their epoch of formation.  相似文献   

The 2dF Galaxy Redshift Survey: the luminosity function of cluster galaxies     

Roberto De Propris  Matthew Colless  Simon P. Driver  Warrick Couch  John A. Peacock  Ivan K. Baldry  Carlton M. Baugh  Joss Bland-Hawthorn  Terry Bridges  Russell Cannon  Shaun Cole  Chris Collins  Nicholas Cross  Gavin B. Dalton  George Efstathiou  Richard S. Ellis  Carlos S. Frenk  Karl Glazebrook  Edward Hawkins  Carole Jackson  Ofer Lahav  Ian Lewis  Stuart Lumsden  Steve Maddox  Darren S. Madgwick  Peder Norberg  Will Percival  Bruce Peterson  Will Sutherland  Keith Taylor 《Monthly notices of the Royal Astronomical Society》2003,342(3):725-737

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Fossils explained 51     

Darren Naish 《Geology Today》2005,21(6):232-238

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