检索结果-南通市图书馆

Resolving impact volatilization and condensation from target rock mixing and hydrothermal overprinting within the Chicxulub impact structure

引用

Geoscience Frontiers 2022年第5期13卷 16-31页

作者： Thomas Déhais Stepan M.Chernonozhkin Pim Kaskes sietze j.de graaff Vinciane debaille Frank Vanhaecke Philippe Claeys Steven Goderis Analytical Environmental and Geo-ChemistryVrije Universiteit BrusselBrusselsBelgium Laboratoire G-Time UniversitécLibre de BruxellesBrusselsBelgium department of Chemistry Atomic&Mass SpectrometryGhent UniversityGhentBelgium

This work presents isotopic data for the non-traditional isotope systems Fe,Cu,and Zn on a set of Chicxulub impactites and target lithologies with the aim of better documenting the dynamic processes taking place during hypervelocity impact events,as well as those affecting impact structures during the post-impact *** focus lies on material from the recent IODP-ICDP Expedition 364 Hole M0077A drill core obtained from the offshore Chicxulub peak *** ejecta blanket samples from the UNAM 5 and 7 cores were used to compare the crater lithologies with those outside of the impact *** datasets of bulk Fe,Cu,and Zn isotope ratios are coupled with petrographic observations and bulk major and trace element compositions to disentangle equilibrium isotope fractionation effects from kinetic *** observed Fe and Cu isotopic signatures,with δ^(56/54)Fe ranging from0.95‰to 0.58‰and δ^(65/63)Cu from0.73‰to 0.14‰,mostly reflect felsic,mafic,and carbonate target lithology mixing and secondary sulfide mineral formation,the latter associated to the extensive and long-lived(>105 years)hydrothermal system within Chicxulub *** the other hand,the stable Zn isotope ratios provide evidence for volatility-governed isotopic *** heavier Zn isotopic compositions observed for the uppermost part of the impactite sequence and a metamorphic clast(δ^(66/64)Zn of up to 0.80‰and 0.87‰,respectively)relative to most basement lithologies and impact melt rock units indicate partial vaporization of Zn,comparable to what has been observed for Cretaceous-Paleogene boundary layer sediments around the world,as well as for tektites from various strewn *** contrast to previous work,our data indicate that an isotopically light Zn reservoir(δ^(66/64)Zn down to0.49‰),of which the existence has previously been suggested based on mass balance considerations,may reside within the upper impact melt rock(UIM)*** observation is restricted to a few UIM sampl

关键词： Chicxulub impact structure Non-traditional stable isotopes Impact volatilization Impact condensation Hydrothermal alteration Target lithology mixing

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

地质模型模拟研究

引用

国外油气勘探 1991年第1期 29-37+52页

作者： W.j.E.Van de graaff 黄忠范

储层的不均匀性是分层次的,因此,为了进行数值模拟研究,需要油藏地质学家用数量来表示不同深度储层的非均匀性。在最大规模,即油田规模内,最重要的参数是砂体的连续性和连通性。在一储层或成因砂体规模上,区域性渗透率趋势、阻渗层的存... 详细信息

储层的不均匀性是分层次的,因此,为了进行数值模拟研究,需要油藏地质学家用数量来表示不同深度储层的非均匀性。在最大规模,即油田规模内,最重要的参数是砂体的连续性和连通性。在一储层或成因砂体规模上,区域性渗透率趋势、阻渗层的存在及分布、渗透率的垂向分布以及方向性渗透特性的存在等,是最关键的参数。在较小规模下,已证明交错层理对变位过程的影响是显著的。事实上,根据较大规模的模拟模型对交错层理的影响进行评价,应当可以得到更有意义的结果。所举的例子揭示出不同规模的储层不均匀性对流体流动形式的一些影响。这些例子表明了要获得很好的模拟结果,对不同规模必须考虑详细的程度。

关键词：储层模型渗透性成因砂体交错层理

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

理论福利经济学

理论福利经济学

引用

作者： j.V.·格拉夫(j.V. graaff)

来源：南通市图书馆图书评论

学校读者我要写书评

暂无评论

新近发生先兆子痫妇女中的异常内皮依赖性微血管活性

引用

世界核心医学期刊文摘（妇产科学分册） 2005年第8期1卷 60-61页

作者： Blaauw j. graaff R. Van Pampus M.G. j.G.Aarnoudse 王伟华 Dr.department of Obstetrics Groningen University Medical Centre Postbox 30.001 9700 RB Groningen Netherlands

OBjECTIVE: To assess endothelial function at the level of skin microvasculature, using iontophoretic administration of acetylcholine (endothelium-dependent vasodilator) and sodium nitroprusside (endothelium-independent vasodilator), in women who recently had a preeclamptic pregnancy. METHODS: Microvascular skin reactivity was assessed by laser Doppler perfusion monitoring and iontophoresis of acetylcholine (ACh) and sodium nitroprusside (SNP) in 25 women with a history of early onset preeclampsia and 23 women with previous uncomplicated pregnancies, all of whom were between 3 and 11 months postpartum. RESULTS: Mean (±.standard error of the mean) ACh-mediated vasodilatation, expressed as a percentage increase in flux, was higher in women who recently had a preeclampsia than in controls (535 ±46%versus 314 ±29%, P derlying (micro)angiopathy.

关键词：内皮依赖性先兆子痫微血管病血管舒张妊娠并发症非依赖性血管扩张剂血管危险因素电渗补偿反应

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Volkswagen公司新型4缸两级涡轮增压直喷式柴油机

引用

汽车与新动力 2015年第4期47卷 19-23页

作者： F Eichler j.Kahrstedt M.Khne M.graaff 范明强

Passat轿车配装两级涡轮增压的直列4缸2.0L直喷式柴油机,具有顶级的机动性。在转速4 000r/min时功率为176kW;在1 750～2 500r/min转速范围内,最大扭矩为500N·m,被升功率高达88kW,这量产4缸柴油机中是最高的。新型柴油机以2012年Volkswa... 详细信息

Passat轿车配装两级涡轮增压的直列4缸2.0L直喷式柴油机,具有顶级的机动性。在转速4 000r/min时功率为176kW;在1 750～2 500r/min转速范围内,最大扭矩为500N·m,被升功率高达88kW,这量产4缸柴油机中是最高的。新型柴油机以2012年Volkswagen公司推出的模块化标准部件为基础[1],匹配具有2个废气涡轮增压器的紧凑型增压机组,增压压力(绝对压力)高达0.38MPa。

关键词：两级涡轮增压共轨喷油系统增压空气冷却器

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Ion Source Optimisation for Proton Beam Quality of the Van de graaff Accelerator at iThemba LABS for Ion Beam Analysis

引用

World journal of Nuclear Science and Technology 2013年第3期3卷 83-86页

作者： M. E. M. Eisa j. L. Conradie P. j. Celliers j. L. G. delsink D. T. Fourie G. de Villiers K. A. Springhorn C. A. Pineda-Vargas Accelerator Group iThemba LABS Somerset West South Africa department of Physics Northern Border University Arar Kingdom of Saudi Arabia department of Physics Sudan University of Science and Technology Khartoum Sudan iThemba LABS Materials Research Department Somerset West South Africa iThemba LABS Materials Research Department Somerset West South Africa Faculty of Health and Wellness Sciences C.P.U.T Bellville South Africa

The operating principles of the two duoplasmatron ion sources and the PIG source available for the Van de graaff accelerator have been determined qualitatively, mainly by studying the extensive literature on ion sources. The main characteristics of the three sources have therefore been determined experimentally on an ion source test bench. Important parameters of the sources such as the pressure and temperature in different regions of the sources not measured, because of space limitations. However, in spite of these limitations in quantitative understanding of the sources, sufficient information to continue with the study of the beam transport through the Van de graaff accelerator and its beamlines could be obtained from these measurements. With regard to beam intensity, lifetime and gas consumption the measurements showed that the hotcathode duoplasmatron is at present by far the most suitable source for the van de graaff accelerator. The emittance of the ion source was measured with two slits, 90 mm apart, and a Faraday cup in the ion source test bench at an arc voltage of 83 V, an arc current of 1 Amp, a filament voltage of 24 V and an extraction voltage of 5 kV. The measured emittance for 90% of the beam intensity is 48π mm mrad. This figure will be used to calculate the beam transmission through the Van de Graaf accelerator. Different computer programs have been used for these calculations from the ion source through the terminal section, the accelerator and beam line up to the Nuclear Microprobe (NMP) for beam quality.

关键词： Van de graaff Beam Optics Ion Source

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：