A5102008866- Geochemistry and Elemental Analysis
- Geological and Geochemical Analysis
- Geology and Paleoclimatology Research
- Methane Hydrates and Related Phenomena
- Geochemistry and Geologic Mapping
- Paleontology and Stratigraphy of Fossils
- earthquake and tectonic studies
- Radioactive element chemistry and processing
- Geological and Geophysical Studies
- Particle physics theoretical and experimental studies
- Quantum Chromodynamics and Particle Interactions
- High-pressure geophysics and materials
- Extraction and Separation Processes
- High-Energy Particle Collisions Research
- Hydrocarbon exploration and reservoir analysis
- Geological Studies and Exploration
- Pesticide and Herbicide Environmental Studies
- Isotope Analysis in Ecology
- Underwater Acoustics Research
- Geomagnetism and Paleomagnetism Studies
- Carbon Dioxide Capture Technologies
- Advanced Sensor and Energy Harvesting Materials
- CO2 Sequestration and Geologic Interactions
- Membrane Separation and Gas Transport
- Bauxite Residue and Utilization
The University of Tokyo
2016-2025
Chiba Institute of Technology
2016-2025
Toshiba (Japan)
2006-2025
Japan Agency for Marine-Earth Science and Technology
2015-2024
National Institute of Advanced Industrial Science and Technology
2024
Frontier Energy (United States)
2013-2023
Nagoya University
1996-2022
Saitama University
2010-2022
Metawater (Japan)
2009-2019
Society of Environmental Toxicology and Chemistry
2000-2017
We report a measurement of the ratio ${\cal R}(D^*) = {\cal B}(\bar{B}^0 \rightarrow D^{*+} \tau^- \bar{\nu}_{\tau})/{\cal \ell^- \bar{\nu}_{\ell})$, where $\ell$ denotes an electron or muon. The results are based on data sample containing $772\times10^6$ $B\bar{B}$ pairs recorded at $\Upsilon(4S)$ resonance with Belle detector KEKB $e^+ e^-$ collider. select $B^0 \bar{B}^0$ by reconstructing both $B$ mesons in semileptonic decays to $D^{*\mp} \ell^{\pm}$. measure R}(D^*)= 0.302 \pm...
Potential risks of supply shortages for critical metals including rare-earth elements and yttrium (REY) have spurred great interest in commercial mining deep-sea mineral resources. Deep-sea mud containing over 5,000 ppm total REY content was discovered the western North Pacific Ocean near Minamitorishima Island, Japan, 2013. This REY-rich has potential as a metal resource because enormous amount available its advantageous mineralogical features. Here, we estimated with Geographical...
Initial subduction-related boninitic magmatism occurred between 48 and 44 Ma in the Izu–Bonin–Mariana (IBM) arc. High-Mg adakites low-Ca boninites have been dredged from Bonin Ridge fore-arc seamount. Whole-rock 40Ar/ 39Ar ages suggest that boninite (44·0 ± 1·4 Ma) adakite (43·1 1·0 40·8 0·8 overlapped, or slightly later than magmatism. The are high-Mg andesites exhibit U-shaped rare earth element (REE) patterns with an elevated average Mg# of 0·78 [Mg# = Mg/(Mg + Fe) molar ratio] Ni content...
Using the entire Belle data sample of 980 ${\rm fb}^{-1}$ $e^+e^-$ collisions, we present results a study excited $\Omega_c$ charmed baryons in decay mode $\Xi_c^+K^-$. We show confirmation four five narrow states reported by LHCb Collaboration: $\Omega_c(3000)$ , $\Omega_c(3050)$, $\Omega_c(3066)$, and $\Omega_c(3090)$.
Metalliferous umbers and red shales occur as unique products of the Kula‐Pacific ridge‐forearc collision in Late Cretaceous Shimanto Supergroup, an accretionary complex Japan. These are closely associated with greenstones mid‐ocean ridge basalt (MORB) origin regarded hydrothermal metalliferous precipitates related to MOR‐type volcanism. The were deposited trench area where both terrigenous detritus from land particulates a MOR supplied simultaneously. Besides predominance Fe Mn, exhibit...
We have discovered deep-sea mud that is extremely enriched in rare-earth elements and yttrium (together called REY) the Japanese Exclusive Economic Zone around Minamitorishima Island, western North Pacific Ocean. The maximum total REY concentration reaches approximately 7000 ppm, which much higher than reported for conventional deposits on land other known potential resources ocean. REY-rich characterized by abundant phillipsite biogenic calcium phosphate. In addition, stratigraphic layer...
Abstract Deep-sea sediments have attracted much attention as a promising resource for rare-earth elements and yttrium (REY). In this study, we show statistically independent components characterising REY-enrichment in the abyssal ocean that are decoded by Independent Component Analysis of multi-elemental dataset 3,968 bulk sediment samples from 101 sites Pacific Indian oceans. This study first time reconstructs spatiotemporal variations geochemical signatures, including hydrothermal,...
A dense field of ferromanganese (Fe-Mn) nodules was discovered on a seamount approximately 300 km east Minamitorishima Island, in the Japanese Exclusive Economic Zone. To evaluate its potential as resource for critical metals, we describe results geological survey using SHINKAI 6500 submersible (dive No. 6K 1207) during cruise YK10-05 R/V Yokosuka 2010, and geochemical analyses collected samples. Submersible observations showed that spherical 5–10 cm diameter almost fully cover region high...
Abstract A certain type of deep‐sea sediment exhibits very high content rare earth elements and yttrium (REY) is therefore expected to serve as a novel resource for these industrially essential metals. In this paper, we statistically analyzed the bulk chemical composition sediments collected from western North Pacific Ocean. By applying independent component analysis multielemental data set, extracted three components (ICs) that can be interpreted influence Mn‐oxides (IC1), REY‐enriched...
Deep-sea sediments containing high concentrations of rare-earth elements and yttrium (REY), termed REY-rich mud, are widely distributed in the Pacific Indian oceans. Mud layers with very total REY (ΣREY) (>5000 ppm ΣREY ~1000 heavy elements) have been discovered within Japanese exclusive economic zone surrounding Minamitorishima Island, western North Pacific. The number highly REY-enriched sediment column, depths at which occur, maximum values are, however, quite variable on a scale several...
Carbonate, the major carbon reservoir on Earth's surface, can enter into mantle by subduction. However, evidence for recycled surficial carbonates in deep is still scarce. Ocean island basalts from Cook-Austral islands and St. Helena Island, widely called HIMU because of their high μ = 238U/204Pb sources, are thought to be fed plumes originating lower mantle. Here we report exceptionally δ66Zn values (δ66Zn 0.38 ± 0.03‰) these lavas relative most published data oceanic 0.31 0.10‰), which...
Abstract Microfossils of fish teeth and denticles, referred to as ichthyoliths, provide critical information for depositional ages, paleo‐environments, marine ecosystems, especially in pelagic realms. However, owing their small size rarity, it is time‐consuming difficult analyze large numbers ichthyoliths from sediment samples, limiting use scientific studies. Here, we propose a method automatically detect microscopic images using deep learning technique. We applied YOLO‐v7, one the latest...
We analyzed 1338 deep-sea sediment samples from 19 Deep Sea Drilling Project/Ocean Program sites covering a large portion of the Indian Ocean, and constructed new comprehensive data set their bulk chemical compositions, including rare-earth, major, trace elements. The bulk-sediment rare-earth yttrium (REY) composition REY-enriched samples, characterized by relatively small negative Ce anomalies, almost no Y enrichment in heavy elements, can be interpreted as superposition REY compositions...