检索结果-南通市图书馆

Secular change in lifetime of granitic crust and the continental growth: A new view from detrital zircon ages of sandstones

引用

Geoscience Frontiers 2018年第4期9卷 1099-1115页

作者： Hikaru Sawada Yukio Isozaki Shuhei Sakata Takafumi Hirata Shigenori Maruyama Department of General System Studies The University of Tokyo Earth-Life Science Institute(elsi) Tokyo Institute of Technology Department of Chemistry Gakushuin University Geochemical Research Center The University of Tokyo

U-Pb ages of detrital zircons were newly dated for 4 Archean sandstones from the Pilbara craton in Australia, Wyoming craton in North America, and Kaapvaal craton in Africa. By using the present results with previously published data, we compiled the age spectra of detrital zircons for 2.9, 2.6, 2.3,1.0, and0.6 Ga sandstones and modern river sands in order to document the secular change in age structure of continental crusts through time. The results demonstrated the following episodes in the history of continental crust：（1） low growth rate of the continents due to the short cycle in production/destruction of granitic crust during the Neoarchean to Paleoproterozoic（2.9-23 Ga）,（2） net increase in volume of the continents during Paleo-to Mesoproterozoic（2.3-1.0 Ga）, and（3） net decrease in volume of the continents during the Neoproterozoic and Phanerozoic（after 1.0 Ga）. In the Archean and Paleoproterozoic, the embryonic continents were smaller than the modern continents, probably owing to the relatively rapid production and destruction of continental crust. This is indeed reflected in the heterogeneous crustal age structure of modern continents that usually have relatively small amount of Archean crusts with respect to the post-Archean ones. During the Mesoproterozoic, plural continents amalgamated into larger ones comparable to modern continental blocks in size. Relatively older crusts were preserved in continental interiors, whereas younger crusts were accreted along continental *** addition to continental arc magmatism, the direct accretion of intra-oceanic island arc around continental peripheries also became important for net continental growth. Since 1.0 Ga, total volume of continents has decreased, and this appears consistent with on-going phenomena along modern active arc-trench system with dominant tectonic erosion and/or arc subduction. Subduction of a huge amount of granitic crusts into the mantle through time is suggested, and this requires re-co

关键词： Detrital zircon U-Pb age Continental growth Subduction erosion Preservation bias

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

Modification of the High-Pressure-Type Chromites into the Low-Pressure-Type: Petrological Investigation of the Podiform Chromitites in the Luobusa Ophiolite, Tibet

引用

Acta Geologica Sinica(English Edition) 2015年第A2期89卷 104-104页

作者： YAMAMOTO Shinji KOMIYA Tsuyoshi MARUYAMA Shigenori Graduate School of Arts and Sciences The University of Tokyo elsi (Earth-Life Science Institute) Tokyo Institute of Technology

The podiform chromitites in the Luobusa ophiolite, Southem Tibet, have received much attention because of the presence of ultrahigh-pressure minerals, such as micro- diamonds （Bai et al., 1993; Yang et al., 2007; Xu ...

关键词：

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

Structural change of molybdenum sulfide facilitates the electrocatalytic hydrogen evolution reaction at neutral pH as revealed by in situ Raman spectroscopy

引用

Chinese Journal of Catalysis 2018年第3期39卷 401-406页

作者： Yamei Li Ryuhei Nakamura Biofunctional Catalyst Research Team RIKEN Center for Sustainable Resource Science (CSRS) 2‐1 Hirosawa Wako Saitama 351‐0198 Japan Earth‐Life Science Institute (elsi) Tokyo Institute of Technology 2‐12‐1‐I7E Ookayama Meguro‐ku Tokyo 152‐8550 Japan

Molybdenum sulfides are promising electrocatalysts for the hydrogen evolution reaction(HER).Sand Mo‐related species have been proposed as the active site for forming adsorbed hydrogen to initiate the HER;however,the nature of the interaction between Mo centers and S ligands is ***,the development of cost‐effective water‐splitting systems using neutral water as a proton source for H2evolution is highly desirable,whereas the mechanism of the HER at neutral pH is rarely ***,the structural change in the Mo?Mo and S?S species in a synthesized molybdenum sulfide was monitored at neutral pH using in situ electrochemical Raman *** of the potential dependent Raman spectra revealed that the band assigned to a terminal S?S species emerged along with synchronized changes in the frequency of the Mo?Mo,Mo3?μ3S,and Mo?S vibrational *** indicates that Mo?Mo bonds and terminal S?S ligands play synergistic roles in facilitating hydrogen evolution,likely via the internal reorganization of trinuclear Mo3?thio *** nature and role of metal‐ligand interactions in the HER revealed in this study demonstrated a mechanism that is distinct from those reported previously in which the S or Mo sites function independently.

关键词： Hydrogen evolution reaction Molybdenum sulfide Electrocatalyst In‐situ Raman spectroscopy Artificial photosynthesis Clean energy

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

人类基因组的伦理和法律问题

引用

科技与法律 2000年第3期 19-31页

作者：邱仁宗中国人类基因组elsi委员会

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

Surface Force Analysis of Pyrite (FeS₂): Its Reactivity to Amino Acid Adsorption

引用

Advances in Materials Physics and Chemistry 2016年第7期6卷 167-176页

作者： Narangerel Ganbaatar Nina Matsuzaki Yuya Nakazawa Rehana Afrin Masashi Aono Taka-aki Yano Tomohiro Hayashi Masahiko Hara Chemical Evolution Lab Unit Earth-Life Science Institute (ELSI) Tokyo Institute of Technology Tokyo Japan Department of Electronic Chemistry Interdisciplinary Graduate School of Science and Engineering Tokyo Institute of Technology Tokyo Japan Global Research Cluster RIKEN Saitama Japan

It is well known that mineral surfaces play an important role as catalysts for abiotic polymerization of amino acids to form peptides, which are the main components of the first self-replicating system. Understanding the mechanism behind the adsorption of simple amino acids on mineral surfaces is a topic of great interest not only in field of prebiotic evolution and but also in many other branches of material sciences. Various clay minerals have been suggested for studying how organic molecules were first synthesized in a prebiotic “inorganic” environment. Among them, pyrite (FeS2) is one of the most potential minerals as it possesses a highly reactive surface to drive molecular adsorption in prebiotic chemistry reactions. Recent theoretical experiments suggest that amino acids are adsorbed on the pyrite surface depending on its surface structures. However, these results have not been tested experimentally, and the exact mechanism of the specific interactions on this mineral has not been fully resolved yet at the molecular level. In this work, through quantitative force analysis with atomic force microscope (AFM) in which a single amino acid residue was mounted on the tip apex of AFM probe, we were able to find the reaction sites and study the interaction forces between the amino acid and the pyrite surface. Our results of Raman spectroscopic studies and force measurements with a well-designed AFM probe demonstrated for the first time that pyrite provided higher adsorption probabilities of amino acid residues for the chemical reactions at surfaces.

关键词： Pyrite Mineral-Organic Interface Atomic Force Microscopy Amino Acid Adsorption

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

High-reliability zircon separation for hunting the oldest material on Earth： An automatic zircon separator with image-processing/microtweezers-manipulating system and double-step dating

引用

Geoscience Frontiers 2018年第4期9卷 1073-1083页

作者： Yukio Isozaki Shinji Yamamoto Shuhei Sakata Hideyuki Obayashi Takafumi Hirata Ken-ichi Obori Toshinori Maebayashi Satoshi Takeshima Toshikazu Ebisuzaki Shigenori Maruyama Department of Earth Science and Astronomy The University of Tokyo Komaba Meguro Tokyo 153-8902 Japan Department of Human Environmental Studies Yokohama National University Hodogaya Yokohama 240-8501 Japan Department of Chemistry Gakushuin University Mejiro Toshima Tokyo 171-8588 Japan Department of Geology and Mineralogy Kyoto University Kitashirakawa Oiwakecho Sakyo-ku Kyoto 606-8502 Japan Geochemical Research Center The University of Tokyo Hongo 7-3-1 Bunkyo Tokyo 113-0033 Japan Horiba Ltd. Kanda Chiyoda Tokyo 101-0063 Japan MicroSupport Co. Ltd. Hiratsuka Kanagawa 254-0035 Japan Mitani Corporation Takada Toshima Tokyo 171-0033 Japan Riken Wako Saitama 351-0198 Japan elsi Tokyo Institute of Technology Meguro Tokyo 152-8551 Japan

Despite the recent development in radiometric dating of numerous zircons by LA-ICPMS, mineral separation still remains a major obstacle, particularly in the search for the oldest material on Earth. To improve the efficiency in zircon separation by an order of magnitude, we have designed/developed a new machine-an automatic zircon separator（AZS）. This is designed particularly for automatic pick-up of100 μm-sized zircon grains out of a heavy mineral fraction after conventional separation procedures. The AZS operates in three modes：（1） image processing to choose targeted individual zircon grains out of all heavy minerals spread on a tray,（2） automatic capturing of the individual zircon grains with microtweezers, and（3） placing them one-by-one in a coordinated alignment on a receiving tray. The automatic capturing was designed/created for continuous mineral selecting without human presence for many hours. This software also enables the registration of each separated zircon grain for dating, by recording digital photo-image, optical（color） indices, and coordinates on a receiving tray. We developed two new approaches for the dating; i.e.（1） direct dating of zircons selected by LA-ICPMS without conventional resin-mounting/polishing,（2） high speed U-Pb dating, combined with conventional sample preparation procedures using the new equipment with multiple-ion counting detectors（LA-MIC-ICPMS）.With the first approach, Pb-Pb ages obtained from the surface of a mineral were crosschecked with the interior of the same grain after resin-mounting/polishing. With the second approach, the amount of time required for dating one zircon grain is ca. 20 s, and a sample throughput of 〉150 grains per hour can be achieved with sufficient precision（ca. 0.5%）.We tested the practical efficiency of the AZS, by analyzing an Archean Jack Hills conglomerate in Western Australia with the known oldest（〉4.3 Ga） zircon on Earth. Preliminary results are positive; we were able to obtain more than 194 zirc

关键词： Hadean Zircon U-Pb dating LA-ICPMS Automatic mineral separator Primordial crust

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

Chronological constraints on the Paleoproterozoic Francevillian Group in Gabon

引用

Geoscience Frontiers 2017年第2期8卷 397-407页

作者： Yusuke Sawaki Mathieu Moussavou Tomohiko Sato Kazue Suzuki Cédric Ligna Hisashi Asanuma Shuhei Sakata Hideyuki Obayashi Takafumi Hirata Amboise Edou-Minkoinko Department of Earth and Planetary Sciences Tokyo Institute of Technology2-12-1 O-okayamaMeguro-kuTokyo 152-8551Japan University of Sdences and Technology in Masuku BP:90190025 FrancevilleGabon Earth-Life Science Institute(elsi) Tokyo Institute of Technology2-12-1 O-okayamaMeguro-kuTokyo 152-8551Japan Department of Chemistry Gakushuin UniversityMejiro 1-5-1Toshima-kuTokyo 171-8588Japan Division of Earth and Planetary Sciences Graduate School of ScienceKyoto UniversityKitashirakawa Oiwake-choSakyo-kuKyoto 606-8502Japan Geochemistry Research Center The University of TokyoHongo 7-3-1Bunkyo-kuTokyo 113-0033Japan

The Francevillian Group in Gabonese Republic was recently established as a typical sedimentary sequence for the ***,its age is rather poorly constrained,mainly based on Rb-Sr and Nd-Sm *** study reports new zircon data obtained from Chaillu massif and N＇goutou complex,which constrain the protolith age of the basement orthogneisses and the igneous age of an intrusive granite,*** zircons from the orthogneisses are blue and exhibit oscillatory zoning in cathode-luminescence *** with lower common lead abundances tend to be distributed close to the concordia *** age clusters around 2860 Ma and 2910 Ma are found in zircons plotted on the concordia *** on the Th/U ratios of zircons,these ages correspond to the protolith ages of the orthogneisses,and the zircons are not metamorphic in *** and granites were collected from the N＇goutou complex that intrudes into the FA and FB units of the Francevillian *** granitoids exhibit chemical composition of A-type granite *** of zircons separated from the granite are non-luminous,and the remaining half exhibit obscure internal textures under cathode-luminescence *** zircon grains contain significant amounts of common lead;the lead isotopic variability is probably attributed to the mixing of two components in the *** zircon radiogenic ^（207）Pb/^（206）Pb ratio is 0.13707 ± *** to a ^（207）Pb/^（206）Pb age of 2191 ± 13 *** constrains the minimum depositional age of the FA and FB ***,the FB unit consists of manganese-rich carbonate rocks and organic carbon-rich black shales with macroscopic *** on our age constraints,these organisms appeared in the study area just after the last Paleoproterozoic Snowball Earth event,in concert with global scale oxidation event encompassing the Snowball Earth.

关键词： Gabon Francevillian Group Paleoproterozoic N'goutou complex Zircon MC-ICP-MS

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

Growth, Duplication and Lateral Mutual Compressive Deformation of Akouemma hemisphaeria on the Seafloor of Okondja Basin at 2.2 Ga (Gabon)

引用

International Journal of Geosciences 2017年第9期8卷 1172-1191页

作者： Ambroise Edou-Minko Mathieu Moussavou Tomohiko Sato Yusuke Sawaki Simplice Ndong Ondo Richard Maire Guillaume Fleury Michel Mbina Mounguengui Anders Kaestner Richard Ortega Stéphane Roudeau Asuncion Carmona Makaya Mvoubou Benjamin Musavu Moussavou Osamu Sasaki Shigenori Maruyama Université des Sciences et Techniques de Masuku Franceville Gabon Earth-Life Science Institute (elsi) Tokyo Institute of Technology Tokyo Japan Department of Earth Science and Astronomy Graduate School of Arts and Sciences The University of Tokyo Tokyo Japan UMR 5319 Passages Maison des Suds CNRS-Université Bordeaux-Montaigne Pessac France Muséum d’Histoire Naturelle de Toulouse Toulouse France Laboratory for Neutron Scattering and Imaging Paul Scherrer Institut Villigen Switzerland CENBG Univ. Bordeaux CNRS IN2P3 UMR 5797 Gradignan France Tohoku University Museum Université de Tohoku Sendai Japan

A colony of macro-fossils Akouemma hemisphaeria has been described in the Paleoproterozoic sedimentary basin of Okondja, Gabon. These fossils are classified into two groups according to their spheroidal or elongated forms. The spheroidal shapes are similar, have a tripartite structure with two hemispheres and a median disc and gradually pass to the elongated forms. These elongated forms have a pronounced bipartite tendency to two “hemispheres” separated by a median surface, and often have several ovoid “pieces” attached. The elongated specimens show both lateral growth marks and signs of fission. Growth marks are characterized by unidirectional homogeneous side elongations and lateral bud-like protuberances. The signs of fission are marked by circular furrows perpendicular to the direction of elongation, called “constriction furrows” with varying depths depending on the degree of fission of the specimen and internal vertical “division planes”. All of these ovoid and elongated specimens have undergone significant initial deformations due mainly to mutual lateral compressions in tabular beds. The Akouemma hemisphaeria macro-organisms, which were primitive probably sessile organisms, lived on the seafloor. They provide the oldest known record of macro-organisms on Earth having vegetative growth and asexual reproduction by budding, lateral elongation and fission. Their mutual lateral deformations would result from their growth.

关键词： Paleoproterozoic Francevillian Group Okondja Basin Akouemma hemisphaeria Growth Duplication

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

Post Cryopreservation Growth Kinetic and Photosynthetic Assessment of an Acid Tolerant Strain of Stichococcus bacillaris

引用

Natural Resources 2024年第5期15卷 130-148页

作者： Marzia Licata Luigi Marra Nunzia Nappi Elena Aurino Feliciana Oliva Antonino De Natale Donato Giovannelli Antonino Pollio Department of Biology University of Naples &#8220Federico II&#8221 Naples Italy ACUF Algal Collection of University of Naples &#8220Federico II&#8221 Naples Italy Department of Chemical Materials and Industrial Production Engineering University of Naples &#8220Federico II&#8221 P.le V. Tecchio Naples Italy Institute for Marine Biological Resources and Biotechnologies Italian National Research Council CNR-IRBIM Ancona Italy Earth-Life Science Institute ELSI Tokyo Institute of Technology Tokyo Japan Marine Chemistry and Geochemistry Department Woods Hole Oceanographic Institution Woods Hole MA USA Department of Marine and Coastal Science Rutgers University New Brunswick NJ USA

Preserving microbial diversity has become a strategic undertaking. Thus, ex situ microalgal culture conservation results in strategic and functional resource in both biodiversity protection and application domains. Cryopreservation of microalgae has been practiced since the 1960s and is now considered the optimal preservation strategy. Furthermore, the overall monitoring during growth of cultures after freezing/thawing protocols was hardly investigated and there is poor evaluation related to preserve especially the photosystem apparatus. The present study focuses on Stichococcus bacillaris as case study for short-term cryopreservation at −80 °C storage. Various freezing pretreatments using cryoprotective agents, and two thawing methods were compared introducing a novel variable to evaluate viability recovery and assessing growth kinetics of cultures immediately after thawing and after a series batch cultivation. Photosynthetic rate and pigments assessment were proposed to evaluate hidden metabolic cell damage. Results underline cryoprotective agents can increase the kinetic recovery of preserved cells in terms of reduction of lag phase during batch cultivation tests: the use of dimethyl sulfoxide and glycerol granted a growth comparable to unpreserved cells when sudden thawing occurs after 24 hours of storage, but recovery after preservation is less sensitive to cryoprotective agents when gradual thawing and 1 month of storage is considered. However, cells are always able to restore their physiological pathways even without agents, so their kinetic effect has been proved and quantified. Interestingly, both the photosynthetic efficiency and the ratio between total chlorophyll and carotenoids are comparable (0.75 Fv/Fm, 2.2 ± 0.25 g/g) to unpreserved cells and they are unsensitive to chosen agents, but the ratio between chlorophyll a and chlorophyll b was clearly altered (up to 10 times), suggesting that photoactive pigments relative proportions

关键词： Microalgae Stichococcus bacillaris Cryopreservation Growth Kinetic Photosynthetic Rate

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

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

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：