首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   36篇
  免费   0篇
测绘学   2篇
地球物理   2篇
地质学   27篇
海洋学   4篇
自然地理   1篇
  2013年   2篇
  2012年   1篇
  2011年   1篇
  2010年   1篇
  2009年   2篇
  2007年   1篇
  2006年   1篇
  2004年   4篇
  2003年   3篇
  2002年   3篇
  2001年   1篇
  2000年   2篇
  1999年   1篇
  1998年   1篇
  1997年   1篇
  1996年   1篇
  1995年   2篇
  1994年   1篇
  1993年   1篇
  1989年   1篇
  1988年   2篇
  1986年   1篇
  1981年   1篇
  1980年   1篇
排序方式: 共有36条查询结果,搜索用时 93 毫秒
1.
Quantitative pyrolysis-gas chromatography has been performed on 96 kerogen samples isolated from 17 wells on the Norwegian Continental shelf. Petrographic and bulk geochemical measurements were also performed on the samples, and a combined data set of 117 variables for each sample was analysed using principal components analysis (PCA). This approach provides an objective and reproducible means of kerogen characterisation, which can be easily automated. In addition to objective kerogen characterisation and facile visualisation of facies and maturity related chemical trends, the method has the potential to allow objective prediction of key geochemical parameters such as maturity level from pyrogram data.  相似文献   
2.
A global kinetic model of vitrinite reflectance evolution is developed to illustrate a new approach to vitrinite reflectance modelling. The method utilizes quantitative pyrolysisgas Chromatographic data from isolated vitrinite kerogens to derive the concentrations of structurally specific moieties (alkylphenol precursors) in vitrinite kerogens as a function of rank. This data set is used to calibrate a gaussian distributed activation energy model for phenol-precursor loss from vitrinites using published burial histories. Phenol yield is then correlated with vitrinite reflectance. The predictive vitrinite reflectance model based on this phenol system is tested against a well from the US Gulf Coast area, the results being compared with a Lopatin model of the same well. This type of vitrinite reflectance model is numerically compatible with current generation kinetic models of hydrocarbon production from source rock kerogens, and has a better heating rate independence than Lopatin's method.
Zusammenfassung Um eine neue Annäherung an das Modellieren der Vitrinit-Reflexion zu demonstrieren, wurde ein global-kinetisches Modell der Entwicklung der Vitrinit-Reflexion erstellt. Die Methode verwendet Daten von quantitativer Pyrolyse-Gas Chromatographie isolierten Vitrinitkerogens, um die Konzentration von strukturspezifischen Moieten (Alkylophenol-Vorläufer) in Vitrinitkerogen als Funktion der Reihenfolge zu erhalten. Verwendet werden diese Daten, um ein nach Gauss verteiltes Aktivierungsenergiemodell zu kalibrieren, das mit Hilfe von veröffentlichten Ablagerungsgeschichten den Phenol-Vorläuferverlust von Vitriniten beschreibt. Die Phenol-Ausbeute wird dann mit der Vitrinit-Reflexion korreliert. Das auf dem Phenolsystem basierende Vitrinit-Reflexionsmodell wird in einem Test einem Bohrloch an der amerikanischen Golfküste gegenübergestellt. Die Ergebnisse werden mit dem Lopatinmodell des selben Bohrlochs verglichen. Diese Art eines Vitrinit-Reflexionsmodells ist numerisch wettbewerbsfähig mit der heutigen Generation kinetischer Modelle der Kohlenwasserstofferzeugung aus Trägergesteinskerogenen. Außerdem ist seine Unabhängigkeit von der Erhitzungsrate größer als mit der Lopatin-Methode.

Résumé L'auteur présente un modèle cinétique global de l'évaluation du pouvoir réflecteur de la vitrinite, afin d'illuster une approche nouvelle dans la modélisation de ce pourvoir réflecteur. Cette méthode utilise des données quantitatives fournies par la pyrolyse combinée à la Chromatographie en phase gazeuse et relatives à des kérogènes de vitrinite. A partir de ces données, on exprime les concentrations des fractions à structure spécifique dans les kérogènes vitrinitiques en fonction du degré d'évolution. A partir de cet ensemble de données, on établit un modèle de l'énergie d'activation selon une distribution gaussienne, applicable à la perte de phénol-précurseur dans les vitrinites, en se référant à cet effet aux déroulements historiques de l'enfouissement fournis par la littérature. La production de phénol est alors mise en relation avec le pourvoir réflecteur de la vitrinite. Le modèle du pouvoir réflecteur prévisible, basé sur ce système des phénols a été contrôlé dans un forage de la côte du golfe du Mexique (USA), et les résultats comparés à ceux du modèle de Lopatin appliqué au même forage. Le modèle présenté est numériquement compatible avec les modèles cinétiques habituels qui rendent compte de la production d'hydrocarbure à partir des kérogènes des roches-mères; il présente une meilleure indépendance que la méthode de Lopatin par rapport au taux d'échauffement.

, , , .. , , - , . , . . , . ; ; .
  相似文献   
3.
A series of hand-picked vitrinite samples from the Lower Kittanning Seam, Pennsylvania have been examined using quantitative pyrolysis-gas chromatography. These vitrinites ranged in rank from 0.59 to 1.71% reflectance, a rank range from high volatile C bituminous to low volatile bituminous. High molecular weight pyrolysis products included alkyl aromatic and phenolic compounds. Attempts have been made to correlate the pyrolysis product composition to rank parameters including vitrinite reflectance, volatile matter yield, carbon content, atomic H/C ratio and Rock-Eval determined Tmax. Total yield of phenols was found to be strongly and inversely rank related. A clear relationship between C8 alkyl-benzene yield and rank was not found for the sample set.  相似文献   
4.
The significance and validity of integrating data obtained from a variety of analytical techniques to understand, elucidate and model kerogen's complex chemical structure is reported here using degradative (open and closed system pyrolysis, chemical oxidation), non-degradative (13C CP/MAS NMR) and optical (incident white light and blue light) methods. Seven Cambrian Alum Shale samples, ranging in maturity from immature to post-mature with respect to petroleum generation, were studied and were chosen for their simple geological history, uniform organic matter type and high organic carbon content. The Alum Shale kerogens, which primarily consist of algal organic matter, liberate low molecular weight gaseous and aromatic compounds on pyrolysis and give mostly branched dicarboxylic acids on chemical oxidation. 13C NMR spectroscopy shows that the Alum Shale kerogens are anomalously rich in oxygen-bearing functional groups (such as C = O, ArCO, CHO, CHxO), most of which apparently remain intact within the kerogen macro-molecule (KMM) through the diagenetic and catagenetic stages. Fragments released by different degradative techniques are quantified and the aromaticity (fa), O/C and relative proportions of various carbon types estimated by 13C NMR. A synthesis of these data has allowed us to better understand the chemistry of the Alum Shale kerogen.  相似文献   
5.
6.
Melanoidins, acidic polymeric products of amino acid/sugar condensation reactions, are shown to be capable of reacting with and binding functionalized lipid molecules. Pyrolysis gas chromatography is used to monitor the inclusion of lipids (alcohols and acids) into, and to monitor the changes in composition caused by artificial diagenesis of, the melanoidins. Artificial diagenesis of the lipidcontaining melanoidins produces a material resembling kerogen. The possible role of melanoidins in the formation of kerogens is discussed as are internal transformations within kerogens during diagenesis.  相似文献   
7.
A re-evaluation of the threat status of New Zealand's marine invertebrates was undertaken in 2009, following earlier review of New Zealand's Threat Classification System and subsequent refinement of the national criteria for classifying threat of extinction to New Zealand's flora and fauna. Sufficient information was available to enable 295 marine invertebrate taxa to be fully evaluated and assigned to a national threat category. The 10 taxa at most risk of extinction (‘nationally critical’) were the giant seep clam Calyptogena sp., the primitive acorn barnacle Chionelasmus crosnieri, O'Shea's vent barnacle Volcanolepas osheai, the stalked barnacle Ibla idiotica, the four-blotched umbrella octopus Cirroctopus hochbergi, the roughy umbrella octopus Opisthoteuthis chathamensis, the giant squid Idioteuthis cordiformis, the large-egged polychaete Boccardiella magniovata and two gravel maggots, Smeagol climoi and Smeagol manneringi. The key threatening processes identified for marine invertebrates were fishing and land-use associated impacts such as sedimentation. We identified no taxa that had improved in threat status as a result of past or ongoing conservation management action, nor any taxa that had worsened in threat status because of known changes in their distribution, abundance or rate of population decline. We evaluated a small fraction of New Zealand's marine invertebrate fauna for their threat status. Many taxa remain ‘data deficient’ or unlisted. In addition to the most threatened taxa, we recommend these taxa and their habitats as priorities for further survey and monitoring.  相似文献   
8.
In coastal populations of invertebrates and fishes, the distribution of discrete subpopulations is influenced by adult and larval dispersal, as well as by the effects of habitat heterogeneity on site fidelity or connectivity. Here, we examine evidence for spatial structure of sea perch, Helicolenus percoides, populations among four fjords in the Fiordland region of southwestern New Zealand. We examine patterns in adult morphology, length-at-age, δ13C and δ15N of muscle tissue, and trace elemental composition of whole otoliths as proxies for population isolation among the four inner fjord regions. A multivariate analysis of morphometrics reveals significant differences among populations from each of the four sites, suggesting existence of four distinct subpopulations. These patterns are consistent with observed differences in δ13C and δ15N, and length-at-age estimates among the four subpopulations. Differences in whole otolith concentrations of Sr, Ba, Mg and Li, and high classification scores based on the whole otolith elemental fingerprint are also consistent with significant subdivision among areas. Patterns across all four markers are consistent with discrete subpopulation structure of adult sea perch among the four study sites. These data indicate that the newly implemented network of marine protected areas in Fiordland is likely to contain discrete populations of sea perch.  相似文献   
9.
A geochemical investigation of oils in sandstone core plugs and drill stem test oils was carried out on samples from a North Sea reservoir. A sample of diesel used as a constituent of the drilling fluids was also analysed. The aliphatic and aromatic hydrocarbons and polar non-hydrocarbons were isolated using solid phase extraction methods. GC analysis of the hydrocarbon fraction of the core extract indicated that contamination may be diesel derived. From analysis of diesel some compound classes are less likely to be affected by contamination from diesel itself including: steranes, hopanes, aromatic steroid hydrocarbons, benzocarbazoles and C0–C3-alkylphenols.  相似文献   
10.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号