Flash heating of calcium‐aluminum‐rich inclusions     

Hiroko Nagahara 《Meteoritics & planetary science》2001,36(8):1011-1012

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Preservation of the shell matrix protein dermatopontin in 1500 year old land snail fossils from the Bonin islands     

Isao Sarashina  Yoshiki Kunitomo  Minoru Iijima  Satoshi Chiba  Kazuyoshi Endo   《Organic Geochemistry》2008,39(12):1742

Organic molecules such as proteins can be preserved in certain fossils. The bulk properties of fossil proteins of both vertebrates and invertebrates have been studied for over half a century. Named proteins have so far been identified, however, only in vertebrate fossils, such as collagen from mammoth bones. Using immunological assays, we examined 1500 year old fossils of the extinct land snail Mandarina luhuana from the Bonin islands for the presence of dermatopontin, a molluscan shell matrix protein. First, we examined the shell microstructure and mineralogy of the fossil shells using scanning electron microscopy (SEM) and powder X-ray diffraction (XRD) in order to estimate the extent of diagenetic alteration. The results suggest that the original microstructure and mineralogy of the shells are preserved. Antiserum raised against the Type-1 dermatopontin fragment of the living land snail Euhadra brandtii showed significant immunological reactivity with the extracts from the fossil shells of M. luhuana. Immunological binding curves drawn for the shell extracts of extant M. aureola and the extinct M. luhuana confirmed the presence of dermatopontin in the fossil shells and provided an estimate that about 75–98% of the original dermatopontin was lost from the M. luhuana fossils. This is the first report of a named protein being identified in invertebrate fossils.  相似文献   

Standing stocks and production rates of phytoplankton and planktonic copepods in the Inland Sea of Japan   总被引：1，自引：0，他引：1  

Shin-ichi Uye  Hiroshi Kuwata  Takuo Endo 《Journal of Oceanography》1986,42(6):421-434

Standing stocks and production rates of phytoplankton and planktonic copepods were investigated at 15 stations in the Inland Sea of Japan during four cruises in October–November 1979, January, April and June 1980. The overall mean of phytoplankton biomass was relatively constant during the study period, ranging from 2.3 mg chl.a m^–3 in April to 3.6 mg chl.a m^–3 in October–November. Primary production was low in January (mean: 90 mg C m^–2 d^–1), but higher than 375 mg C m^–2 d^–1 on the other occasions. Integrated annual primary production was 122 g C m^–2 yr^–1. In terms of carbon weight,Paracalanus parvus was the most important copepod species. The variation of the mean copepod biomass (range: 7.6 mg C m^–3 in April to 20.2 mg C m^–3 in June) was smaller than that of copepod production, which was estimated by the Ikeda-Motoda's physiological method. Copepod producion was low in cold seasons (0.6 and 0.9 mg C m^–3 d^–1 in January and April, respectively), and increased, following the elevation of primary production, to 4.9 mg C m^–3 d^–1 in June. Annual copepod production was 33.7 g C m^–2 yr^–1, of which herbivore (secondary) production was 26.4 g C m^–2 yr^–1 (21.7% of primary production). The ratios of pelagic planktivorous fish catch and total fish catch to the primary production were 0.82 and 1.8%, respectively, indicating very high efficiency in exploiting fishery resources in the Inland Sea of Japan.  相似文献   

Flux determination over a smooth surface under strongly unstable conditions     

Michiaki Sugita  Tetsuya Hiyama  Nobuhiko Endo  Shao-Fen Tian 《Boundary-Layer Meteorology》1995,73(1-2):145-158

Careful micrometeorological measurements on an empty parking lot allowed determination of the surface fluxes of sensible heatH and of momentum by applying profile equations derived from Monin-Obukhov similarity theory with two sets of the stability correction function for momentum _m and sensible heat _h . These fluxes were compared with reference values ofH independently determined by means of an eddy correlation technique. In general, better agreement was found betweenH values derived from profiles with the stability functions of Brutsaert (1992) and referenceH values, than when the Businger-Dyer functions were used to deriveH. The disagreement in the latter comparison was especially serious under strongly unstable conditions, with the value ofy=–z/L (wherez is the height andL is the Obukhov length) larger than 10. A closer look at the procedure for calculatingH from the profiles revealed that the large differences between theH values derived with these two different versions of the stability correction functions were caused by the small differences of the _h values, and not by the larger differences of the _m values. This result stems from the strong sensitivity of the resultingH values on the choice of _h .  相似文献   

Cation distribution in pentlandites (Fe,Ni)9S8: Dependence on pressure and temperature and kinetics of the cation exchange reaction     

Katsuhiro Tsukimura  Hiromoto Nakazawa  Tadashi Endo  Osamu Fukunaga 《Physics and Chemistry of Minerals》1992,19(4):203-212

This paper describes the distribution of Fe and Ni between the octahedral and tetrahedral sites in pentlandite (Fe,Ni)₉S₈. The dependence of the distribution on pressure and temperature and the activation energy of the cation exchange reaction were determined through annealing experiments. Synthetic crystals were annealed at 433–723 K and pressures up to 4 GPa, and natural crystals were annealed at 423, 448 and 473 K in evacuated silica capillary tubes for various durations. The cation distributions in the synthetic crystals were determined with an X-ray powder method employing the anomalous dispersion effect of CuK. and FeK radiations, while those of natural crystals were calculated from the cell dimensions. The values of U, S and V for the Fe/Ni exchange reaction are –6818 J mol^–1, 20.52 J K^–1 mol^–1, and 6.99 × 10^–6 m³ mol^–1, respectively. The dependence of the Fe/Ni distribution on pressure (Pa) and temperature (Kelvin) was determined as lnK = 2.47+8.20 × 10² T ^–1+8.41 x 10^–7 T ^–1 P, where K = (Fe/Ni)_octahedral /(Fe/Ni)_tetrahedral. The activation energy of the cation exchange reaction was 185 kJ mol^–1.  相似文献   

Measuring the k–S–p relations on DNAPLs migration     

Masashi Kamon  Kazuto Endo  Takeshi Katsumi 《Engineering Geology》2003,70(3-4):351-363

Migration characteristics of dense non-aqueous phase liquids (DNAPLs) in the subsurface can be expressed as a water–DNAPL two-phase system based on mainly the k–S–p relations, which describe the relations among relative permeability (k), degree of water saturation (S), and capillary pressure head (p). The aims of this research are to develop an experimental system with new type of probes, such as the electrical conductivity probe for measuring the degree of water saturation and the hydrophilic and hydrophobic tensiometer for measuring the pore water and DNAPL pressures, and also to estimate the results obtained from the developed experimental system. From these tests, the excellent k–S–p relations were obtained and the efficiency and validity of this developed experimental system have been confirmed in terms of the concept of the scaling coefficient calculated by interfacial tensions.  相似文献   

Effects of inertial and kinematic interaction on seismic behavior of pile with embedded foundation   总被引：4，自引：0，他引：4  

Kohji Tokimatsu  Hiroko Suzuki  Masayoshi Sato 《Soil Dynamics and Earthquake Engineering》2005,25(7-10):753-762

Effects of inertial and kinematic forces on pile stresses are studied based on large shaking table tests on pile-structure models with a foundation embedded in dry and liquefiable sand deposits. The test results show that, if the natural period of the superstructure, T_b, is less than that of the ground, T_g, the ground displacement tends to be in phase with the inertial force from the superstructure, increasing the shear force transmitted to the pile. In contrast, if T_b is greater than T_g, the ground displacement tends to be out of phase with the inertial force, restraining the pile stress from increasing. With the effects of earth pressures on the embedded foundation and pile incorporated in, pseudo-static analysis is conducted to estimate maximum moment distribution in pile. It is assumed that the maximum moment is equal to the sum of the two stresses caused by the inertial and kinematic effects if T_b<T_g or the square root of the sum of the squares of the two if T_b>T_g. The estimated pile stresses are in good agreement with the observed ones regardless of the occurrence of soil liquefaction.  相似文献   

Temporal Evolution of a Rapidly-Moving Umbral Dot     

Hiroko Watanabe  Alexandra Tritschler  Reizaburo Kitai  Kiyoshi Ichimoto 《Solar physics》2010,266(1):5-16

We performed two-dimensional spectroscopic observations of the preceding sunspot of NOAA 10905 located off disk center (S8 E36, μ≈0.81) by using the Interferometric BI-dimensional Spectrometer (IBIS) operated at the Dunn Solar Telescope (DST) of the National Solar Observatory, New Mexico. The magnetically insensitive Fe I line at 709.04 nm was scanned in wavelength repetitively at an interval of 37 s to calculate sequences of maps of the line-wing and line-core intensity, and the line-of-sight Doppler velocity at different line depths (3% to 80%). Visual inspection of movies based on speckle reconstructions computed from simultaneous broadband data and the local continuum intensity at 709.04 nm revealed an umbral dot (UD) intruding rapidly from the umbral boundary to the center of the umbra. The apparent motion of this object was particularly fast (1.3 km s⁻¹) when compared to typical UDs. The lifetime and size of the UD was 8.7 min and 240 km, respectively. The rapid UD was visible even in the line-core intensity map of Fe I 709.04 nm and was accompanied by a persistent blueshift of about 0.06 km s⁻¹.  相似文献   

Petrogenesis and implications of jadeite‐bearing kyanite eclogite from the Sanbagawa belt (SW Japan)     

S. Endo  M. Tsuboi 《Journal of Metamorphic Geology》2013,31(6):647-661

Jadeite‐bearing kyanite eclogite has been discovered in the Iratsu body of the Sanbagawa belt, SW Japan. The jadeite + kyanite assemblage is stable at higher pressure–temperature (P–T) conditions or lower H₂O activity [a(H₂O)] than paragonite, although paragonite‐bearing eclogite is common in the Sanbagawa belt. The newly discovered eclogite is a massive metagabbro with the peak‐P assemblage garnet + omphacite + jadeite + kyanite + phengite + quartz + rutile. Impure jadeite is exclusively present as inclusions in garnet. The compositional gap between the coexisting omphacite (P2/n) and impure jadeite (C2/c) suggests relatively low metamorphic temperatures of 510–620 °C. Multi‐equilibrium thermobarometry for the assemblage garnet + omphacite + kyanite + phengite + quartz gives peak‐P conditions of ~2.5 GPa, 570 °C. Crystallization of jadeite in the metagabbro is attributed to Na‐ and Al‐rich effective bulk composition due to the persistence of relict Ca‐rich clinopyroxene at the peak‐P stage. By subtracting relict clinopyroxene from the whole‐rock composition, pseudosection modelling satisfactorily reproduces the observed jadeite‐bearing assemblage and mineral compositions at ~2.4–2.5 GPa, 570–610 °C and a(H₂O) >0.6. The relatively high pressure conditions derived from the jadeite‐bearing kyanite eclogite are further supported by high residual pressures of quartz inclusions in garnet. The maximum depth of exhumation in the Sanbagawa belt (~80 km) suggests decoupling of the slab–mantle wedge interface at this depth.  相似文献   

Governance of disaster emergency wells in three cities in Japan affected by earthquakes     

Endo  Takahiro  Iizuka  Tomoki  Koga  Hitomi  Hamada  Nahoko 《Hydrogeology Journal》2023,31(5):1147-1163

Concern has grown regarding how public and private sectors should make effective use of local groundwater to alleviate negative impacts of water-supply cutoff following an earthquake event, which can be regarded as an emergency groundwater governance problem. Existing literature on groundwater governance, however, is based on the tacit assumption of groundwater utilization under normal social conditions, and scant consideration has been given to the role of groundwater following occurrence of a natural disaster. This study conducted questionnaire surveys to reveal how groundwater was used in three cities (Kumamoto, Sapporo, and Sendai) in Japan struck by large earthquakes between 2010 and 2020. Results revealed substantial differences between these cities in terms of groundwater utilization following earthquake occurrence. The time between the restoration of the electricity supply and restoration of the waterworks, and the social capital accumulated by local governments, are indicated as possible reasons for such differences. Analysis also identified policy challenges for improved groundwater governance in an emergency: (1) establishment of a strategy for emergency water supply through combined use of groundwater and other water sources, (2) enhancement of methods for timely inspection of groundwater quality following occurrence of a disaster, (3) maintenance of records of the number of registered disaster emergency wells (DEWs), (4) creation of methods for publicizing locational information on DEWs with adequate regard for the privacy of well owners, and (5) recognition of the importance of making DEWs part of overall disaster preparedness.

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