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排序方式: 共有109条查询结果,搜索用时 421 毫秒
1.
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
2.
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
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
3.
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
4.
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
5.
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
6.
Polymetallic Mineralization at the Suttsu Vein-type Deposit, Southwestern Hokkaido, Japan 总被引:1,自引:0,他引:1
Abstract. The Suttsu polymetallic vein-type deposit, hosted by tuff, tuff breccia and shale of the Miocene Kunnui Formation and propylitized hornblende-augite andesite, is located in southwestern Hokkaido, Japan. It has been exploited and explored for Cu, Pb, Zn and Ag until 1962.
In this study, we examined K-Ar ages, ore mineralogical characteristics and fluid inclusions to obtain new data for the deposit.
The K-Ar ages on sericite indicate that the polymetallic mineralization occurred in Late Miocene (8.1–5.7 Ma). The polymetallic banded ore from the Ohkubo vein is characterized by an abundance of Au, Ag, Sn, Bi, in, Se and Te. These metals are mainly ascribed to electrum (30.3–37.8 atom% Ag), Se-bearing pavonite (8.5–9.5 wt% Se), gustavite-lillianite solid solution, Se-bearing bismuthinite (5.0–5.3 wt% Se), kawazulite, cassiterite, Sn-bearing chalcopyrite (3.3–4.2 wt% Sn), In-bearing stannite, stannite-chalcopyrite solid solution, and In- and Sn-bearing sphalerite (2.6–8.4 wt% In and 1.8–4.3 wt% Sn), occurring in narrow bands of the ore. The In- and Sn-bearing sphalerite likely forms a sphalerite-roquesite-stannite solid solution with the contents of roquesite and stannite being about 2–9 and 2-A mole%, respectively. Temperatures and salinities (in wt% NaCl equiv.) of the ore fluids are estimated to be 180-250C and 3–4 wt%, respectively. The Sn-bearing chalcopyrite therefore probably precipitated metastably. The geologic and mineralogical features suggest that pre-Tertiary basement rocks rich in organic material underlie the Miocene Kunnui Formation nearby the deposit and that they contributed to local and temporary reduction of magnetite-series magmas favorable for the early stage tin-polymetallic mineralization. 相似文献
In this study, we examined K-Ar ages, ore mineralogical characteristics and fluid inclusions to obtain new data for the deposit.
The K-Ar ages on sericite indicate that the polymetallic mineralization occurred in Late Miocene (8.1–5.7 Ma). The polymetallic banded ore from the Ohkubo vein is characterized by an abundance of Au, Ag, Sn, Bi, in, Se and Te. These metals are mainly ascribed to electrum (30.3–37.8 atom% Ag), Se-bearing pavonite (8.5–9.5 wt% Se), gustavite-lillianite solid solution, Se-bearing bismuthinite (5.0–5.3 wt% Se), kawazulite, cassiterite, Sn-bearing chalcopyrite (3.3–4.2 wt% Sn), In-bearing stannite, stannite-chalcopyrite solid solution, and In- and Sn-bearing sphalerite (2.6–8.4 wt% In and 1.8–4.3 wt% Sn), occurring in narrow bands of the ore. The In- and Sn-bearing sphalerite likely forms a sphalerite-roquesite-stannite solid solution with the contents of roquesite and stannite being about 2–9 and 2-A mole%, respectively. Temperatures and salinities (in wt% NaCl equiv.) of the ore fluids are estimated to be 180-250C and 3–4 wt%, respectively. The Sn-bearing chalcopyrite therefore probably precipitated metastably. The geologic and mineralogical features suggest that pre-Tertiary basement rocks rich in organic material underlie the Miocene Kunnui Formation nearby the deposit and that they contributed to local and temporary reduction of magnetite-series magmas favorable for the early stage tin-polymetallic mineralization. 相似文献
7.
Taro Takahashi Stewart C. Sutherland Rik Wanninkhof Colm Sweeney Richard A. Feely David W. Chipman Burke Hales Gernot Friederich Francisco Chavez Christopher Sabine Andrew Watson Dorothee C.E. Bakker Ute Schuster Nicolas Metzl Hisayuki Yoshikawa-Inoue Masao Ishii Takashi Midorikawa Yukihiro Nojiri Arne Krtzinger Tobias Steinhoff Mario Hoppema Jon Olafsson Thorarinn S. Arnarson Bronte Tilbrook Truls Johannessen Are Olsen Richard Bellerby C.S. Wong Bruno Delille N.R. Bates Hein J.W. de Baar 《Deep Sea Research Part I: Oceanographic Research Papers》2009,56(11):2075-2076
8.
9.
Kazutaka Yamaoka Yoshihiro Ueda Hajime Inoue Fumiaki Nagase Ken Ebisawa Taro Kotani Yasuo Tanaka 《Astrophysics and Space Science》2001,276(1):19-22
We summarize the ASCA observations of the two Galactic superluminal sources GRO J1655–40 and GRS 1915+105, focusing on theabsorption line features.The high spectroscopic capability of ASCA enabled us to detectiron-K absorption line features from both objects. This is direct evidence for the presence of highly ionized plasma in a non-spherical configuration around a black hole, and is considered to be a unique signature of superluminal jet systems. The candidate of the line-absorber would be a part of an accretion disk at a distance of 109-11 cm from the central X-ray source. 相似文献
10.
Petrogenesis and implications of jadeite‐bearing kyanite eclogite from the Sanbagawa belt (SW Japan)
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