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河南南阳独山发现橄榄质科马提岩 被引量:2
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作者 邓燕华 缪秉魁 张曼 《桂林冶金地质学院学报》 1989年第4期349-359,共11页
我国已发现十几处科马提岩,但绝大部分是科马提质玄武岩,而不是河南南阳独山发现的橄榄质科马提岩。独山科马提岩中的矿物,95%是橄榄石(现大部分已蚀变为蛇纹石、滑石和磁铁矿)、少量为单斜辉石(现大部分已蚀变为蛇纹石和滑石)和铬铁... 我国已发现十几处科马提岩,但绝大部分是科马提质玄武岩,而不是河南南阳独山发现的橄榄质科马提岩。独山科马提岩中的矿物,95%是橄榄石(现大部分已蚀变为蛇纹石、滑石和磁铁矿)、少量为单斜辉石(现大部分已蚀变为蛇纹石和滑石)和铬铁矿等。岩石县各种形态的鬣刺结构,鬣刺最长可达30cm,岩石含SiO_2 32.00%~40.00%,MgO 30.00%~37.88%,TiO_20.02%~0.10%,K_2O 0.00%~0.02%,CaO/Al_2O_3大部分小于1。在岩石化学图中,化学分析数据全部落在橄榄质科马提岩区。 展开更多
关键词 橄榄质 科马提岩 超基性岩 河南
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熔盐法制备镁橄榄石轻质保温隔热材料的物相及性能 被引量:10
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作者 张小军 祝洪喜 +2 位作者 邓承继 员文杰 丁军 《机械工程材料》 CAS CSCD 北大核心 2015年第2期26-29,共4页
以Na2CO3和不同粒径的镁橄榄石粉(分别为44,74,250μm)为主要原料,采用熔盐法分别在900,1 000,1 050,1 100℃下烧结制备了镁橄榄石轻质保温隔热材料,研究了镁橄榄石粉粒径和烧结温度对所制备材料物相组成、密度和抗压性能的影响。结果表... 以Na2CO3和不同粒径的镁橄榄石粉(分别为44,74,250μm)为主要原料,采用熔盐法分别在900,1 000,1 050,1 100℃下烧结制备了镁橄榄石轻质保温隔热材料,研究了镁橄榄石粉粒径和烧结温度对所制备材料物相组成、密度和抗压性能的影响。结果表明:所有试样的主要物相均为Mg2SiO4、Na2MgSiO4和MgO,但各物相的含量不同;烧结温度越高,镁橄榄石粉粒径越小,烧结试样的显气孔率越低,体积密度越大,抗压强度越高;粒径为74μm的镁橄榄石粉为原料经1 000℃烧结后得到的试样有比较好的气孔分布和较高的强度,其体积密度为1.76g·cm-3,抗压强度为12.31MPa。 展开更多
关键词 熔盐法 橄榄石轻保温隔热材料 烧结温度
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新疆巴楚地区金伯利质角砾橄榄岩物质组成及含矿性研究 被引量:11
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作者 鲍佩声 苏犁 +1 位作者 翟庆国 肖序常 《地质学报》 EI CAS CSCD 北大核心 2009年第9期1276-1301,共26页
本文讨论出露于新疆巴楚瓦吉里塔格地区的一种角砾状超镁铁岩,其结构、成分复杂,由超镁铁岩包体、斑晶(或捕晶)及基质三部分构成。超镁铁岩包体常见单辉辉石岩、纯橄岩,其次有少量橄榄辉石岩。研究表明均属基性岩浆结晶岩,本次研究未见... 本文讨论出露于新疆巴楚瓦吉里塔格地区的一种角砾状超镁铁岩,其结构、成分复杂,由超镁铁岩包体、斑晶(或捕晶)及基质三部分构成。超镁铁岩包体常见单辉辉石岩、纯橄岩,其次有少量橄榄辉石岩。研究表明均属基性岩浆结晶岩,本次研究未见幔源橄榄岩包体;斑晶主要为橄榄石,次为金云母,基质由微晶(10~40μm)单斜辉石、钙铁榴石、钙钛矿、磁铁矿(或含钛磁铁矿)、蛇纹石、碳酸盐及金属硫化物等组成;捕晶包括单斜辉石、褐色角闪石、磷灰石、含钛磁铁矿等。多种地球化学判别图均指示其属金伯利岩类,但低MgO和低Mg#比值、高TFe2O3和CaO等区别于世界典型金伯利岩。与典型金伯利岩有相似之处,该类岩石均具有向右陡倾的REE配分型式,但(La/Yb)n比值略偏低;微量元素蛛网图也与典型金伯利岩基本一致,仅显示更加富集不相容元素,具有更显著K,Ti负异常,且部分样品出现Rb,Zr,P负异常,指示其源区地幔交代程度偏低。鉴于岩石的产状、结构构造、矿物组合和地球化学性质近似于金伯利岩,但缺少高铬铬铁矿、镁铝榴石、镁钛铁矿等金伯利岩指示矿物,故不属典型的金伯利岩,可称之为金伯利质角砾橄榄岩。就少量研究样品所示信息,该类岩石不具有寻找金刚石的潜在远景,但鉴于巴楚及邻区尚有许多角砾状超镁铁岩岩墙和岩脉出露,该区金刚石成矿条件有待更进一步的研究。 展开更多
关键词 新疆 巴楚 金伯利角砾橄榄 金刚石 含矿性
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轻质镁橄榄石砖的研制 被引量:3
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作者 袁广亮 蒋明学 《耐火材料》 CAS 北大核心 2010年第5期375-376,共2页
以陕西商南的镁橄榄石为原料,以石油焦粉为造孔剂(其加入质量分数分别为30%、35%、40%),分别采用羧甲基纤维素、硅溶胶、MgCl2.6H2O为结合剂,以5 kN的压力成型后,分别于1 250、1 300、1 350℃保温3 h煅烧,测试烧后试样的线变化率、体积... 以陕西商南的镁橄榄石为原料,以石油焦粉为造孔剂(其加入质量分数分别为30%、35%、40%),分别采用羧甲基纤维素、硅溶胶、MgCl2.6H2O为结合剂,以5 kN的压力成型后,分别于1 250、1 300、1 350℃保温3 h煅烧,测试烧后试样的线变化率、体积密度及耐压强度。结果表明:以MgCl2.6H2O为结合剂,加入40%质量分数的石油焦,经1 300℃保温3 h煅烧,可制备出体积密度为1.15 g.cm-3,耐压强度为3.58 MPa的轻质镁橄榄石砖。 展开更多
关键词 橄榄 煅烧温度 结合剂 石油焦
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中间包用镁橄榄石质涂抹料的研制与使用 被引量:3
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作者 马青花 闫芳 +1 位作者 曾广娅 马晓清 《耐火材料》 CAS 北大核心 2010年第4期315-316,共2页
关键词 橄榄 涂抹料 中间包 资源丰富 化学稳定性 金属熔液 分布范围 镁钙砂
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钢包用镁橄榄石质耐火材料
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作者 韩行禄 《国外耐火材料》 1993年第7期25-27,共3页
关键词 橄榄 耐火材料 钢包
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东乌珠穆沁旗中铁陨石表面的角砾状橄榄石的特征 被引量:1
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作者 陶克捷 杨主明 +1 位作者 张培善 韩秀玲 《岩石学报》 SCIE EI CAS CSCD 北大核心 2001年第2期321-324,共4页
东乌珠穆沁旗中铁陨石中有二种橄榄石。一种是陨石中基质橄榄石 ,另一种是镶嵌在陨石表面的角砾状橄榄石。电子探针成分分析结果表明 ,两种橄榄石中的 Fe O和 Mn O比值 ,包体矿物种类 ,包体铁纹石和镍纹石中 Fe,Ni的含量等 ,均有较大区... 东乌珠穆沁旗中铁陨石中有二种橄榄石。一种是陨石中基质橄榄石 ,另一种是镶嵌在陨石表面的角砾状橄榄石。电子探针成分分析结果表明 ,两种橄榄石中的 Fe O和 Mn O比值 ,包体矿物种类 ,包体铁纹石和镍纹石中 Fe,Ni的含量等 ,均有较大区别。陨石中基质橄榄石矿物是本陨石中原物质 ,而角砾状橄榄石是宇宙中物质。 展开更多
关键词 东乌珠穆沁旗中铁陨石 橄榄 原生透铁橄榄 角砾状橄榄 镁铁橄榄
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申扎县日拉组索尔碎屑岩成因及时代探讨 被引量:3
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作者 曲洪晔 赵华伟 +1 位作者 王春阳 李学斌 《吉林地质》 2013年第2期17-19,共3页
索尔碎屑岩是吉林省地质调查院在进行1/25万多巴区幅区域地质调查时建立的非正式地层单位。该套地层不整合于辉石橄榄岩之上,以其独特的岩石类型及岩石组合,揭示了永珠蛇绿岩带在晚侏罗世拉开时形成了橄榄质海山,在其周围裙裾堆积的沉... 索尔碎屑岩是吉林省地质调查院在进行1/25万多巴区幅区域地质调查时建立的非正式地层单位。该套地层不整合于辉石橄榄岩之上,以其独特的岩石类型及岩石组合,揭示了永珠蛇绿岩带在晚侏罗世拉开时形成了橄榄质海山,在其周围裙裾堆积的沉积环境特征。 展开更多
关键词 索尔碎屑岩 橄榄质海山 裙裾堆积
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硼泥耐火材料的研究 被引量:9
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作者 罗玉萍 王立久 《耐火材料》 CAS 北大核心 1994年第6期331-335,共5页
采用X射线衍射分析(XRD)、扫描电子显微镜分析(SEM)及能谱分析(EDS)研究了以硼泥为主要原料制备的镁橄榄石质试样的组成和结构,并对试样的力学性能及高温使用性能进行了测试。结果表明,利用工业废料硼泥制备耐火材料... 采用X射线衍射分析(XRD)、扫描电子显微镜分析(SEM)及能谱分析(EDS)研究了以硼泥为主要原料制备的镁橄榄石质试样的组成和结构,并对试样的力学性能及高温使用性能进行了测试。结果表明,利用工业废料硼泥制备耐火材料是可行的. 展开更多
关键词 橄榄 耐火材料 硼泥 XRD SEM EDS
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Sensory Evaluation of Extra Virgin Olive Oil (EVOO) Extended to Include the Quality Factor "Harmony" 被引量:1
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作者 A. Bongartz D. G. Oberg 《Journal of Agricultural Science and Technology(A)》 2011年第3X期422-435,共14页
Sensory evaluation of olive oil, meaning the official organoleptic assessment of olive oil respectively the "Panel Test" (PT), is based on the standards of the International Olive Council (IOC), as well as on th... Sensory evaluation of olive oil, meaning the official organoleptic assessment of olive oil respectively the "Panel Test" (PT), is based on the standards of the International Olive Council (IOC), as well as on the Regulation (EC) 640/2008 of the European Commission. These regulations lead to the classification of olive oil as "extra virgin" (EVOO), "virgin" (VOO) or "lampant", which however is not sufficient to clearly discriminate between different quality levels within the grade EVOO. The objective of the study at hand was to develop and validate an objective sensory evaluation method for the quality certification of olive oil within the grade EVOO. A new rating system, including a detailed description and evaluation of the complexity and persistence of flavour, was established. First, a comparison between different profile sheets from various olive oil competitions (Ercole Olivario, Premio Biol, Leone D'Oro Mario Solinas Award, among others) and the official profile sheet from the IOC/EC for the panel test (PT) took place. In consecutive steps the basic test procedure from the panel test (PT) then was extended with additional sensory descriptors. Two trained olive oil panels (the German Olive Oil Panel (DOP) and the Swiss Olive Oil Panel (SOP)) were further educated to profile various green and ripe aroma components and to evaluate the complexity of the perceived aroma components and their persistency (descriptor: "harmony/persistency"). This extended methodology was cross-validated over a time period of 3 years between the two panels (DOP/SOP). 展开更多
关键词 Extra Virgin Olive Oil (EVOO) sensory quality panel test complexity HARMONY PERSISTENCY quality certification COMPETITION trade.
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Mantle plume activity and melting conditions: Evidence from olivines in picritic-komatiitic rocks from the Emeishan Large Igneous Province, southwestern China 被引量:10
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作者 Zhaochong Zhang Jingwen Mao +2 位作者 Fusheng Wang Yanli Hao John J. Mahoney 《Episodes》 SCIE 2005年第3期171-176,共6页
Olivine phenocryst compositions and whole-rock chemical compositions are used to identify primitive picrite basalts from the early part of flood basalt successions in the western part of the Emeishan large igneous pro... Olivine phenocryst compositions and whole-rock chemical compositions are used to identify primitive picrite basalts from the early part of flood basalt successions in the western part of the Emeishan large igneous province (ELIP), southwestern China. The Fo contents of olivine phenocrysts of komatiites with MgO-21.79 wt% range from 85.2% to 91.4%. The composition of unerupted parental melts is calculated from the compositions of the most Fo-rich olivine phenocrysts. These melts had -22 wt% MgO, and originated in mantle with a potential temperature of -1600℃ and at about 4.2 GPa pressure, supporting the conclusion that the generation of ELIP can be attributed to melting of a plume head beginning at -138 km depth. 展开更多
关键词 PERMIAN-TRIASSIC BOUNDARY FLOOD BASALTS SW CHINA GEOCHEMICALCONSTRAINTS HAWAIIAN VOLCANISM PERIDOTITE KLB-1 ICELAND PLUME HIGH-MG MAGMAS LAVAS
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Thermodynamic properties of San Carlos olivine at high temperature and high pressure
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作者 Chang Su Yonggang Liu +3 位作者 Wei Song Dawei Fan Zhigang Wang Hongfeng Tang 《Acta Geochimica》 EI CAS CSCD 2018年第2期171-179,共9页
In this study, the thermal expansion and heat capacity of San Carlos olivine under high temperature and high pressure are reported. Combining accurate sound velocity data under different P–T conditions with density a... In this study, the thermal expansion and heat capacity of San Carlos olivine under high temperature and high pressure are reported. Combining accurate sound velocity data under different P–T conditions with density and heat capacity data at ambient pressure, the density,adiabatic bulk modulus, shear modulus, and most importantly, thermal expansion and heat capacity, of San Carlos are extracted to 14 GPa by a numerical procedure using classic thermodynamic relationships. These data are in agreement with published findings. To estimate the temperature gradient in the upper mantle, we also report the fitting equations of thermal expansion and heat capacity of San Carlos olivine as a function of both temperature and pressure to the P–T condition of the 410 km discontinuity,which provide the thermodynamic properties with increasing depth in the Earth's interior. 展开更多
关键词 San Carlos olivine Thermodynamic property Thermal expansion Heat capacity Temperature gradient
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Evaluation of Selected Quality Degradation Indices for Palestinian Extra Virgin Olive Oil Bottled in Different Packaging Materials upon Storage under Different Lighting Conditions
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作者 Ibrahim Abdullah Afaneh Jehad Abbadi +2 位作者 Ziad Ayyad Wadie Sultan Khalid Kanan 《Journal of Food Science and Engineering》 2013年第5期267-283,共17页
The effect of packaging materials and lighting conditions on quality of extra virgin olive oil (EVOO) was investigated during six months. The results highlighted an influence of light and type of packaging material ... The effect of packaging materials and lighting conditions on quality of extra virgin olive oil (EVOO) was investigated during six months. The results highlighted an influence of light and type of packaging material on EVOO-quality with storage time. At shelf, all packages maintained EVOO at the end of storage in terms of acidity, peroxide value, K232, while K270 exceeded limit of EVOO in glass and PET-stored oil. Loss of phenols was the highest in glass-stored oil and the lowest in high-density polyethylene (HDPE)-stored oil. In terms of sensory evaluation, glass-stored oil lost EVOO grade after three months and its edible compliance after six months, while HDPE-stored oil maintained EVOO grade 90 days and was virgin after six months. In extended lighting, acidity, peroxide value and K232 did not exceed EVOO grade, while K270 exceeded EVOO grade after 30 days in glass and polyethylene terephthalate (PET)-stored oil and after 90 days in HDPE. The loss of phenols was the largest in glass and smallest in HDPE-stored oil. Glass stored-oil lost organoleptic edible compliance before 90 days, while that in PET was virgin at 90 days and that in HDPE maintained EVOO quality 90 days. At the end of experiment, oils in all packages were not edible. In dark, all packages maintained oil in EVOO quality in terms of all indices. The loss of phenols was marginal but was the least in glass and the highest in HDPE. It was concluded that HDPE bottles conserve stored olive oil at shelf or illumination better than PET or glass, while in dark, glass was superior over plastic. 展开更多
关键词 ACIDITY oil oxidation olive oil stability indicators storage conditions
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Variation of the Content of Ethyl Esters in Extra Virgin Olive Oils during Their Shelf Life
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作者 Maria A. Grompone Nicolas Callejas +3 位作者 Natalia Martinez Camila Feller Miguel Amarillo Bruno A. Irigaray 《Journal of Food Science and Engineering》 2016年第1期21-25,共5页
Fatty acids' ethyl and methyl esters are not natural components of edible vegetable oils and therefore should not be present in virgin olive oils. Among the quality requirements for extra virgin olive oils, the Inter... Fatty acids' ethyl and methyl esters are not natural components of edible vegetable oils and therefore should not be present in virgin olive oils. Among the quality requirements for extra virgin olive oils, the International Olive Council (IOC) Norm, 2015 review, set limits for the ethyl ester content at ≤ 435 ppm for the 2014/2015 and 2015/2016 harvests and at ≤ 30 ppm for the 2016/2017 harvest. The purpose of this paper is to: (a) determine the alkyl ester content in two extra virgin olive oils (of the Arbequina and Coratina varieties) as parameters of quality at the moment of their elaboration and to assess the length of their shelf life, over a 12 month period at room temperature; (b) determine extra virgin olive oils' free alcohols content as these may esterify due to the free fatty acids present during storage. After 6 months of storage, the Arbequina oil's ethyl ester content was 32 ppm, and the Coratina's was 46 ppm. As a result, the shelf life for both was only about half a year (labeling usually indicates it must be consumed "before 1 year"). However, parameters related to oxidation (peroxide index, K 232, K 270 and AK) remained within the limits set by the International Olive Council (IOC) throughout the year. In conclusion: ethyl ester content is a very fine parameter for assessing the quality of extra virgin in an olive oil and determining the length of its shelf life. 展开更多
关键词 Alkyl esters free alcohols olive oil shelf life
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Chemical and Sensory Properties of Olive Oil as Influenced by Different Sources of Irrigation Water
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作者 Salam Ayoub Saleh AI-Shdiefat +1 位作者 Hamzeh Rawashdeh IbrahimBashabsheh 《Journal of Agricultural Science and Technology(A)》 2013年第2期105-112,共8页
This research was conducted throughout the years 2008-2010 to study the influence of irrigation water quality on oil quality of "Nabali Muhassan" olive trees. Reclaimed municipal wastewater and fresh water were used... This research was conducted throughout the years 2008-2010 to study the influence of irrigation water quality on oil quality of "Nabali Muhassan" olive trees. Reclaimed municipal wastewater and fresh water were used twice a week using drip irrigation system. Rainfed olive trees of the same farm were taken as control. No significant differences were observed between rainfed, fresh water and reclaimed wastewater treatments in terms of acidity, peroxide values and UV absorbance of the extracted olive oil. Heavy metals and microbiological pathogens were not detected in all tested olive oil samples. Oleic acid was significantly higher in olive oil obtained from rainfed trees than irrigated trees. Linoleic acid content was significantly higher in reclaimed wastewater irrigated trees than the rainfed trees. Total polyphenol contents were significantly higher in oil obtained from rainfed olive trees than oil obtained from the irrigated olive trees. Results of organoleptic analysis showed no significant differences in the fruity attribute within treatments, while the bitter and pungent attributes were higher in olive oil obtained from rainfed trees as compared to that obtained from irrigated trees. No negative attributes were observed in oil obtained from the irrigated or rainfed trees and they were all classified as extra virgin grade. 展开更多
关键词 Olive oil IRRIGATION reclaimed wastewater fresh water rainfed trees total phenols.
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Petroqenesis of Subduction Zone and Dunite Bodies
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作者 Ayse Didem Klh9 《Journal of Earth Science and Engineering》 2012年第7期377-386,共10页
The dunite bodies, which extend as the direction of W-E, are exposed to the southeast of Elazlg located within the Eastern Taurus Belt of Turkey. Mafic-Ultramafic section in the Guleman ophiolite consists ofdunite whi... The dunite bodies, which extend as the direction of W-E, are exposed to the southeast of Elazlg located within the Eastern Taurus Belt of Turkey. Mafic-Ultramafic section in the Guleman ophiolite consists ofdunite which containing disseminated chromites, wehrlite, gabbros (isotrope gabbro and layered gabbro) and clinopyroxenite. Dunite blocks above the harzburgite massif have irregular contacts with the enclosing peridotites. Dunite blocks are generally around a few of meters. Dunite blocks consist of gabbro and pyroxenite patches. The origin of dunite blocks are belong to the transition zone of harzburgitic ophiolites which is located at the base of the mafic layered section. They are entirely or largely magmatic formed by olivine and chromite ponds at the base of the crustal magma chamber. The rather around of rock pieces within dunite bodies are foliated such as features have been ascribed to the ophiolite being impregnated by and reacting with a melt. Rocks in the bodies show depleted in incompatible trace elements such as Ba, Nbet al., characteristic of subduction related magma. Furthermore, the high LREE/HREE and high Rb/Th ratios indicates a mantle that has been enrichmented by subduction. As a result, isotopic data, petrographic and geochemical of bodies's result suggest a parental magma derived from an enrichmed source of subduction zone. A few meters of the large dunite bodies, and ascribes to the central dunites a cumulative origin by fractionation from a picritic melt. 展开更多
关键词 Neotethyan TURKEY dnite bodies subduction zone OPHIOLITE geochemistry.
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Influence of Metrological Factors Variations between Eastern and Western Foothills on Olive Oil Quality: A Case Study in Northern West Bank
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作者 M. N. Amama A. M. Marei F. S. AI-Rimawi 《Journal of Agricultural Science and Technology(B)》 2011年第3期407-413,共7页
This Study investigated the effect of metrological factors variations between eastern and western foothills on olive oil quality in northern West Bank. Samples were collected from two villages: Assera A1 Shamalia (l... This Study investigated the effect of metrological factors variations between eastern and western foothills on olive oil quality in northern West Bank. Samples were collected from two villages: Assera A1 Shamalia (locates on Western foothills) and Bet Dagan (Locates on Eastern foothills). Differences in metrological factors and harvesting times between the two villages cause differences in olive oil quality and higher content of stigmastadiene in Bet Dagan than Assera olive oil. The higher monthly averages of minimum and maximum temperatures of Bet Dagan cause the increase of Stigmastadiene content of olive oil. While the higher amount of precipitation in Assera; cause higher quality and quantity of produced olive oil in Assera compared to Bet Dagan. The lower relative humidity and longer day hours; in Assera village enhances higher amounts of olive oil accumulation and better quality as this is the favorable conditions for olive oil formation. The compression between Cuba, Crete, Spain and Italy olive oil quality with Palestinian olive oil quality, we found that Palestinian olive oil shows good competition quality parameters for acidity and peroxide values according to the international olive oil council limits compared with these countries olive oil acidity and peroxide values. 展开更多
关键词 Sterenes metrological factors stigmastadiene foothills.
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The Panel Test as the Metrology of Extra Virgin Olive Oil Quality Evaluation and Its Dissemination
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作者 Maurizio Caciotta Sabino Giarnetti +3 位作者 Fabio Leccese Barbara Orioni Marco Oreggia Salvatore Rametta 《Journal of Food Science and Engineering》 2014年第4期203-211,共9页
Nowadays, the check of the organoleptic characteristics for the evaluation of extra virgin olive oil (EVOO) quality is regulated by the European Union (EU) authorities, which indicate the use of the panel test (P... Nowadays, the check of the organoleptic characteristics for the evaluation of extra virgin olive oil (EVOO) quality is regulated by the European Union (EU) authorities, which indicate the use of the panel test (PT). It is composed by a team of specialists that give a numerical value to many characteristics about flavours, synthesising a sensory analysis. Each expert answers questions about the aroma by assigning the adequate scores to each oil. The evaluation becomes objective by applying the statistical analysis of all the scores given by the participants: This is the definition of "measure" of Russell. The PT can be considered a true standard "metrological system" (considering the number of questions in the questionnaire), while the perceptions of the testers are the solicitations of it. To allow access to an expensive evaluation process by small companies, this work proposes to "disseminate" the properties of the metrology represented by PT. The results of the PT are arranged in an unsupervised artificial neural network (ANN), the Kohonen map, which represents the synthesis of self-organised output that has only the goal, in this paper, to make readable PT results. The dissemination process is obtained by the gas chromatographic (GC) analysis of each oil sample and through the identification of peaks corresponding to the perceptions. These signals are used for the training of the supervised Multi Layer Perceptron (MLP) ANN, with the back propagation algorithm, whose outputs are represented by the results of the PT. This procedure is exact a "metrological dissemination of a standard" and also the aim of the work: to classify EVOO without always resorting to PT. 展开更多
关键词 EVO0 quality evaluation gas chromatography ANN.
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Talc-bearing serpentinized peridotites from the southern Mariana forearc:implications for aseismic character within subduction zones
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作者 汪小妹 曾志刚 +8 位作者 刘长华 陈俊兵 殷学博 王晓媛 陈代庚 张国良 陈帅 李康 欧阳荷根 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2009年第3期667-673,共7页
The serpentinized peridotites overlying the subducted zones in the Izu-Bonin-Mariana(IBM) arc system have been interpret as the cause of the low-velocity layer identified beneath the IBM froearc,in turn few earthquake... The serpentinized peridotites overlying the subducted zones in the Izu-Bonin-Mariana(IBM) arc system have been interpret as the cause of the low-velocity layer identified beneath the IBM froearc,in turn few earthquakes occurred along the plate boundary.Chrysotile,which is a low temperature and highly hydrated phase of serpentine with low frictional strength,has been suggested as the low velocity material in the serpentinized peridotites,besides,brucite is inferred to be likely conducive to stable sliding.However,such idea encounters challenging in our serpentinized peridotites from the southern Mariana forearc,which absent both the above minerals.The presence of talc,which characterized by its weak,low-friction and inherently stable sliding behavior,provides new clue.Here we report the occurrence of talc in serpentinized peridotites collected from the landward trench slope of the southern Mariana forearc.We infer that talc is mainly forming as a result of the reaction of serpentine minerals with silica-saturated fluids released from the subducting slab,and talc also occurs as talc veins sometimes.Due to its unique physical properties,talc may therefore play a significant role in aseismic slip in the IBM subduction zone. 展开更多
关键词 TALC serpentinized peridotites MARIANA aseismic subducfion zone
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Homologous temperature of olivine: Implications for creep of the upper mantle and fabric transitions in olivine 被引量:5
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作者 WANG Qin 《Science China Earth Sciences》 SCIE EI CAS CSCD 2016年第6期1138-1156,共19页
The homologues temperature of a crystalline material is defined as T/Tm, where T is temperature and Tm is the melting (solidus) temperature in Kelvin. It has been widely used to compare the creep strength of crystal... The homologues temperature of a crystalline material is defined as T/Tm, where T is temperature and Tm is the melting (solidus) temperature in Kelvin. It has been widely used to compare the creep strength of crystalline materials. The melting temperature of olivine system, (Mg,Fe)2SiO4, decreases with increasing iron content and water content, and increases with confining pressure. At high pressure, phase transition will lead to a sharp change in the melting curve of olivine. After calibrating previous melting experiments on fayalite (Fe2SiO4), the triple point of fayalite-Fe2SiO4 spinel-liquid is determined to be at 6.4 GPa and 1793 K. Using the generalized means, the solidus and liquidus of dry olivine are described as a function of iron content and pressure up to 6.4 GPa. The change of T/Tm of olivine with depth allows us to compare the strength of the up- per mantle with different thermal states and olivine composition. The transition from semi-brittle to ductile deformation in the upper mantle occurs at a depth where T/Tm of olivine equals 0.5. The lithospheric mantle beneath cratons shows much smaller T/Tm of olivine than orogens and extensional basins until the lithosphere-asthenosphere boundary where T/Tm 〉 0.66, suggesting a stronger lithosphere beneath cratons. In addition, T/Tm is used to analyze deformation experiments on olivine. The results indicate that the effect of water on fabric transitions in olivine is closely related with pressure. The hydrogen-weakening effect and its relationship with T/Tm of olivine need further investigation. Below 6.4 GPa (〈200 kin), T/TIn of olivine controls the transition of dislocation glide from [100] slip to [001] slip. Under the strain rate of 10-12-10-15 s-1 and low stress in the upper mantle, the [100](010) slip system (A-type fabric) becomes dominant when T/TIn〉 0.55-0.60. When T/Tm〈 0.55-0.60, [001] slip is easier and low T/Tm favors the operation of [001](100) slip system (C-type fabric). This is consistent with the widely observed A-type olivine fabric in naturally deformed peridotites, and the C-type olivine fabric in peridotites that experienced deep subduction in ultrahigh-pressure metamorphic terranes. However, the B-type fabric will develop under high stress and relatively low T/Tm. Therefore, the homologues temperature of olivine established a bridge to extrapolate deformation experi- ments to rheology of the upper mantle. Seismic anisotropy of the upper mantle beneath cratons should be simulated using a four-layer model with the relic A-type fabric in the upper lithospheric mantle, the B-type fabric in the middle layer, the newly formed A- or B-type fabric near the lithosphere-asthenosphere boundary, and the asthenosphere dominated by diffusion creep below the Lehmann discontinuity. Knowledge about transition mechanisms of olivine fabrics is critical for tracing the water distribution and mantle flow from seismic anisotropy. 展开更多
关键词 OLIVINE Homologous temperature Lattice preferred orientation Water Seismic anisotropy Upper mantle
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