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Application of an impact plate-Bedload transport measuring system for high-speed flows

International Journal of Sediment Research 2018年第1期33卷 35-46页

作者： Takahiro Koshiba Christian Auel Daizo Tsutsumi Sameh A.Kantoush Tetsuya Sumi Water Resources Research Center Disaster Prevention Research Institute Kyoto University ILF Consulting Engineers hodaka sedimentation observatory Research Center for Fluvial and Coastal Disasters Disaster Prevention Research Institute Kyoto University

To achieve the sustainable use of dams, the development of methods for sediment management in reservoirs is required. One such method includes the use of Sediment Bypass Tunnels(SBTs) to divert sediment around a dam, thereby preventing sedimentation in the reservoir. However, SBTs are prone to severe invert abrasion caused by the high sediment flux. Therefore, it is necessary to establish a measurement system of the sediment transport rate in these tunnels. One system to measure sediment transport in rivers is the Swiss plate geophone, which can register plate vibrations caused by particle impact. In Japan, the Japanese pipe microphone is used, and sediment transport is measured based on the sound emitted by the particle impact. In this study an attempt was made to optimize the advantages of both systems by fixing a microphone and an acceleration sensor to a steel plate. The results of calibration experiments with this new system are presented and compared with the existing methods. It was found that the acceleration sensor can detect sediment particles larger than 2 mm in ***, a new parameter, referred to as the detection rate, was introduced to describe the correlation between the actual amount of sediment and the registered output. Finally, two parameters-the saturation rate and hit rate-are introduced and exhibit strong correlation with the detection rate.(?) 2018 International Research and Training Centre on Erosion and sedimentation/the World Association

关键词： Sediment Bypass Tunnel Bedload Acoustic measurement Geophone Hydrophone High-speed flow

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Global distribution of geothermal gradients in sedimentary basins

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Geoscience Frontiers 2023年第6期14卷 478-495页

作者： Folarin Kolawole Jonathan C.Evenick Lamont-Doherty Earth observatory at Columbia University New YorkNYUSA INPEX Corporation TokyoJapan

The heat budget of sedimentary basins is determined by heat transfer across the lithosphereasthenosphere boundary and lithospheric heat sources,such that the tectonic evolution of their host continental and oceanic lithosphere ultimately impact the present-day heat flow and average geothermal *** increase in availability of publicly-accessible geothermal gradient measurements across the world provides an opportunity to globally assess the dominant controls on the thermal regime of sedimentary ***,we compile a global dataset of152,000 unique data points with constrained bottomhole temperature measurements and assess the relationships between geothermal gradient and selected independent tectonic variables,including crustal and lithospheric thicknesses,crustal age,sediment thickness,and basin *** results show that in both oceanic and continental settings,geothermal gradients exhibit a non-linear,systematic variation with the tectonic *** find that oceanic geothermal gradients decrease with increasing crustal age and lithospheric *** gradients in the continents show no clear relationships with thermotectonic crustal age,but decrease with increasing crustal and lithospheric *** drop significantly at 1.5 km sediment-cover thickness,likely reflecting the effect of high sedimentation rates,but show a striking rise at>12 km thicknesses,potentially influenced by thinned lithosphere and thermal blanketing *** commonly-assumed‘normal’gradient of 25℃/km for continents is only valid for a narrow range(1.5–12.5 km)of sedimentary cover-thickness,and oceanic‘normal’gradient may be as high as 50–75℃/km for>20 Ma crustal age and>50 km-thick *** show that,conditionally,crustal age may best predict average geothermal gradients in oceanic settings,and lithosphere thickness in ***,we observe that tectonic basin types exhibit distinct ranges of gradients that reflect their prevalent tec

关键词： Geothermal gradient Oceanic crust Continental crust Lithosphere Tectonics

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Radiative transfer modeling of three T Tauri stars: selecting candidates for studying circumstellar disk evolution

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Research in Astronomy and Astrophysics 2013年第7期13卷 841-848页

作者： Yao Liu Hong-Chi Wang Sebastian Wolf David Madlener Purple Mountain observatory&Key Laboratory for Radio Astronomy Chinese Academy of Sciences Graduate University of Chinese Academy of Sciences Institut für Theoretische Physik und Astrophysik Universitt zu Kiel

We present modeling work on three young stellar objects that are promis-ing targets for future high-resolution observations to investigate circumstellar disk evolution. The currently available data comprise the spectral energy distribution from optical to millimeter wavelengths which allow constraining the structure of the cir-cumstellar disk using self-consistent radiative transfer models. The results suggest that the assumption of well-mixed dust and gas leads to overestimation of flux in the far-infrared. Observational and theoretical arguments suggest that an overall decrease in far-infrared excess can be explained by dust settling towards the midplane. A new disk model is hence employed to take the effect of dust sedimentation into account. The extended model satisfactorily reproduces all existing observations. The three tar-gets studied here therefore deserve follow-up observations to reveal the evolutionary state of their protoplanetary disks.

关键词： circumstellar matter - planetary systems: protoplanetary disks - ra-diative transfer

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Plio-Pleistocene sedimentation and palaeogeographic reconstruction in the Poso Depression,Central Sulawesi,Indonesia:from a sea channel to a land bridge

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Journal of Palaeogeography 2023年第3期12卷 331-357页

作者： Abang Mansyursyah Surya Nugraha Ramadhan Adhitama Adam D.Switzer Robert Hall Earth observatory of Singapore Nanyang Technological University50 Nanyang Ave.639798Singapore Fakultas Teknologi Kebumian dan Energi Universitas TrisaktiKampus A Gedung DJI.Kyai Tapa No.1GrogolJakarta 11441Indonesia Asian School of the Environment Nanyang Technological University50 Nanyang Ave.639798Singapore SE Asia Research Group Department of Earth SciencesRoyal Holloway University of LondonEghamSurreyTW200EXUK

The Poso Depression provides a record of Plio-Pleistocene environments and palaeogeography of Central ***-based sedimentological and provenance studies suggest that during the Pliocene the Poso Depression was a sea channel connecting Gorontalo and Bone bays formed in an asymmetric *** Pliocene history began with deposition of the Puna Formation with fan deltas at the eastern basin margin and channel complexes in the deep-water basin further *** of light and heavy minerals indicate the main sediment source was ultrabasic rocks in East Sulawesi with minor and intermittent magmatic and metamorphic input from West ***,in the Middle to Late Pliocene,carbonates of the Poso Formation accumulated on the eastern basin *** are unconformably overlain by shallow marine glaucophane-rich siliciclastics of the Pleistocene Lage Formation that are associated with the rapid exhu-mation and uplift of the Pompangeo metamorphic *** uplift led to the development of a land bridge connecting western and eastern *** terrane evolution favoured increasing the area of exposed land due to rapid tectonic uplift,which when combined with the tropical climate,contributed to faunal speciation and dispersal in Sulawesi.

关键词： Palaeogeography Poso Sulawesi sedimentation history Provenance

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Detailed sedimentary structure of the Mianning segment of the Anninghe fault zone revealed by H/V spectral ratio

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Earthquake Research Advances 2023年第3期3卷 19-29页

作者： Zeqiang Chen Huajian Yao Xihui Shao Song Luo Hongfeng Yang Laboratory of Seismology and Physics of Earth's Interior School of Earth and Space SciencesUniversity of Science and Technology of ChinaHefei230026China Mengcheng National Geophysical observatory University of Science and Technology of ChinaMengcheng233500China CAS Center for Excellence in Comparative Planetology University of Science and Technology of ChinaHefei230026China Earth System Science Programme Faculty of ScienceThe Chinese University of Hong KongHong Kong999077China Shenzhen Research Institute The Chinese University of Hong KongShenzhen518057China

The Anninghe fault is a major left-lateral strike-slip fault in southwest China and a seismic gap with a potential earthquake larger than MW 7.0 lies in the Mianning-Xichang segment according to recent *** shallow structure of this region can offer a glimpse into the geometry of the fault,which plays an important role in earthquake hazard *** further investigate the sedimentary structure of the Anninghe fault zone,two dense linear arrays with a station spacing of around 80 m were deployed across the *** this study,the H/V spectral ratio(HVSR),together with its peak frequency at each station site,was obtained by applying the Nakamura *** findings demonstrate that the peak frequency behaves in high correlation with lithology and is controlled by *** in foothills or regions with magmatic intrusion shows a single peak at about 2–3 *** locations with abundant Quaternary sedimentation,such as Anninghe valleys and fracture zones,another low-frequency peak around 0.4 Hz can be noticed in *** using the empirical relationship,the thickness of the sedimentary layer around the fault fracture zone is estimated to be 300–600 ***,the sedimentary interface shows a downward dip to the east,possibly influenced by the east-west extrusion *** the resonance effect,buildings with 6–9 stories in the valley area of the Anninghe require additional attention in earthquake hazard prevention.

关键词： HVSR Shallow structure Anninghe fault zone Sediment Earthquake hazard prevention

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Aeolian dust dynamics in the Fergana Valley, Central Asia, since -30 ka inferred from loess deposits

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Geoscience Frontiers 2021年第5期12卷 93-109页

作者： Yue Li Yougui Song Dimitris G.Kaskaoutis Jinbo Zan Rustam Orozbaev Liangcheng Tan Xiuling Chen State Key Laboratory of Loess and Quaternary Geology Institute of Earth EnvironmentChinese Academy of SciencesXi’an 710061China CAS Center for Excellence in Quaternary Science and Global Change Xi’an 710061China Institute for Environmental Research and Sustainable Development National Observatory of AthensAthens 11810Greece Environmental Chemical Processes Laboratory Department of ChemistryUniversity of CreteCrete 71003Greece Center for Excellence in Tibetan Plateau Earth Sciences Chinese Academy of SciencesBeijing 100101China Key Laboratory of Continental Collision and Plateau Uplift Institute of Tibetan Plateau ResearchChinese Academy of SciencesBeijing 100101China Institute of Geology National Academy of Sciences of Kyrgyz RepublicBishkek 720040Kyrgyzstan Research Center for Ecology and Environment of Central Asia(Bishkek) Bishkek 720040Kyrgyzstan Institute of Geography Fujian Normal UniversityFuzhou 350007China State Key Laboratory for Subtropical Mountain Ecology of the Ministry of Science and Technology and Fujian Province Fujian Normal UniversityFuzhou 350007China

Knowledge of the interactions among atmospheric dynamics,dust emissions and climate system is essential to understand the physical mechanisms for the dust lifecycle,their role in loess formation as well as the predictions of future dust ***,these issues still remain relatively poorly known in Central Asia(CA).The extensive loess deposits on the CA pediments provide a promising archive to explore atmospheric dust dynamics and climatic conditions in the past and their association with loess *** study investigates the granulometric and magnetic properties of a loess section(named Osh section)in the Fergana Valley,which provides a sensitive record of atmospheric dust dynamics since 30 ka based on radiometric(AMS ^(14)C)*** frequency-dependent magnetic susceptibility(χfd)and the mean grain size are used to reconstruct the broadscale effective moisture and summer atmospheric dynamics pattern in CA,*** results show that the precession forcing exerts a huge influence on the wind-regime variabilities in CA,but with different physical processes under the impact of the Northern Hemisphere ice sheet(NHIS)before and after 15 *** origin of the sedimentation rate variations in the Osh loess is also linked to the NHIS-modulated changes of the atmospheric circulation *** the strengthened westerlies or the increased surface roughness from higher vegetation cover in loess-deposition areas have significantly accelerated the loess *** a result,these complicated influence factors of sedimentation rate change in the Osh loess section,especially during the Holocene epoch,may hamper accessibility of the authentic dust emission flux and atmospheric dust concentration in CA.

关键词： Dust dynamics Climate Atmospheric patterns Loess Ice volume Fergana Valley

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