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241.
Estrogen equivalent concentration of individual isomer-specific 4-nonylphenol in Ariake sea water, Japan 总被引:3,自引:0,他引:3
Kim YS Katase T Horii Y Yamashita N Makino M Uchiyama T Fujimoto Y Inoue T 《Marine pollution bulletin》2005,51(8-12):850-856
Concentrations of 4-nonylphenol (NP) were determined by isomer-specific quantification of individual NP isomers based on relative response factor (RRF) quantification with GC–MS in combination with steam distillation extraction. Concentrations of NP in the Ariake Sea decreased with distance from the river mouth (St.A; 49 ng NP/l) to offshore areas (St.C; 11 ng NP/l). Even the least concentration in water from St.C in Ariake Sea was sufficient to have adverse effects on barnacles. The isomers, NP1–NP14 were separated by GC–PFC and identified structurally with NMR. The isomers varied in estrogenic activity with NP7 exhibiting the greatest estrogenic activity with a potency that was approximately 1.9 × 10−3 that of 17β-estradiol (E2) in recombinant yeast screen system. The coefficient of variation (CV) of NP isomer’s concentrations among three samples at St.A, B and C were 4–75%. This suggests that NP isomers might be independently degraded in aquatic environmental samples. The predicted estrogenic activity of measured concentrations of NP in Ariake Sea was 2.7–3.0-fold greater than the measured estrogen agonist activity. 相似文献
242.
Eiji Ohtani Naohisa Hirao Tadashi Kondo Masayoshi Ito Takumi Kikegawa 《Physics and Chemistry of Minerals》2005,32(1):77-82
We observed a direct reaction of metallic iron with water to form iron hydride and iron oxide, 3Fe + H2O–>2FeHx + FeO, at pressures from 6 GPa to 84 GPa and temperatures above 1,000 K in diamond anvil cell (DAC). Iron hydride is dhcpFeHx or -FeHx, and iron oxide has the rhombohedral or B1 structure at pressures at least up to 37 GPa. The formation of an assembly composed of dhcpFeHx and FeO with the B8 structure was observed at 84 GPa. In primordial Earth, water formed by dehydration of the low temperature primitive materials reacts with metallic iron in the high temperature component to form iron hydride FeHx and iron oxide FeO. The former would be incorporated in the iron forming the core. Thus hydrogen could be an important element of the Earths core. This reaction would be essential for transport of hydrogen into the core in the accretion stage of the Earth. 相似文献
243.
244.
Tadashi Yokoyama 《Celestial Mechanics and Dynamical Astronomy》1984,33(2):99-109
A strongly nonlinear Hamiltonian system which occurs in Celestial Mechanics is studied by the method of surface of section. The reappearance of ordered motions is observed and the numerical experiments suggest that this phenomenon could be predicted by the criterion of interaction of resonances. 相似文献
245.
The computed variation of the infrared flux and polarization of Venus as a function of phase angle, based upon multiple-scattering calculations for the cloud model of Kawabata et al. (1980) with an internal heat source, precludes the possibility of sulfuric acid as the composition of the haze particles located above the main cloud. Furthermore, our calculations reveal that the hazticle should have a large absorption coefficient at these wavelengths, i.e, . The optical thickness of the haze layer must be about 0.15 at λ = 3.4 μm. 相似文献
246.
Aiming Lin Tadashi Maruyama Stallard Aaron Katsuyoshi Michibayashi Alfredo Camacho Ken-ichi Kano 《Tectonophysics》2005,402(1-4):21
The Woodroffe thrust, central Australia, is a > 1.5-km-wide mylonitized shear zone marked by large volumes of mm- to cm-scale pseudotachylyte veins. The pseudotachylytes display typical melt-origin features, including rounded and embayed clasts, spherulitic and dentritic microlites, and flow structures within a fine-grained matrix. Three types of pseudotachylyte are identified on the basis of deformation texture, vein morphology, and host-rock lithology: cataclasite-related (C-Pt), mylonite-related (M-Pt), and ultramylonite-related (Um-Pt). The M-Pt and Um-Pt veins intrude into mylonite and ultramylonite and are themselves overprinted by subsequent mylonitization. These pseudotachylytes contain an internal foliation defined by flattened porphyroclasts and layering of the fine-grained vein matrix, and the foliation is generally oriented parallel to foliation in the surrounding mylonite and ultramylonite. These observations constrain the timing and environment of M-Pt and Um-Pt pseudotachylyte formation to a protracted period of deformation and mylonitization within the ductile regime of the crust. The M-Pt and Um-Pt veins, as well as the host mylonite, are overprinted by cataclasis and multiple generations of late-stage C-Pt veins that were generated in the brittle-dominated regime of the upper crust during uplift and exhumation of the shear zone.The coexistence of multiple generations of voluminous C-Pt, M-Pt, and Um-Pt veins indicates that the pseudotachylyte veins represent a large number of large earthquakes and accompanying seismic slip over an extended period of seismicity on the Woodroffe thrust. The timing and distribution of pseudotachylyte indicate that the earthquakes nucleated at the base of the brittle-dominated seismogenic zone and propagated down through the brittle–ductile transition into the ductile-dominated regime of the crust. 相似文献
247.
T. Kawai B.F. Windley M. Terabayashi H. Yamamoto Y. Isozaki S. Maruyama 《Gondwana Research》2008,14(1-2):105
We report the first occurrence of ice-rafted dropstones in mid-oceanic sediments belonging to an ocean plate stratigraphy within a Neoproterozoic accretionary complex on Llanddwyn Island, Wales, UK. Dropstones of sandstone, chert, and basalt occur as matrix-supported exotic clasts in a 1 m-thick, hemi-pelagic mafic mudstone; the largest clast is 20 × 25 cm across. These dropstones occur specifically in hemi-pelagic mafic mudstone that is located at the structural top of ocean plate stratigraphy that records a ridge-trench transition; they are supplementary to dropstones associated with extensive tillites reported in shallow marine sequences of continental shelf facies and in back-arc basins. 相似文献
248.
The Kurosegawa zone in southwest Japan is a 600 km long serpentinite mélange in the Chichibu terrains. It runs generally E-W but is slightly oblique to the subparallel arrangement of the Ryoke, Sanbagawa and Chichibu belts of Southwest Japan. A variety of geological units occurs in the Kurosegawa zone:
- 1. (1) granodiorite, gneiss and amphibolite of ca. 400 Ma,
- 2. (2) Siluro-Devonian formations,
- 3. (3) Upper Carboniferous to Jurassic formations,
- 4. (4) Upper Jurassic to Lower Cretaceous formations,
- 5. (5) serpentinite and
- 6. (6) low- to medium-grade metamorphic rocks of various baric types (ages, 220, 320, 360 and 420 Ma by K-Ar).
249.
Numerical modeling of thermal structure, circulation of H2O, and magmatism–metamorphism in subduction zones: Implications for evolution of arcs 总被引:2,自引:2,他引:0
Numerical models on thermal structure, convective flow of solid, generation and transportation of H2O-rich fluid in subduction zones are consolidated to have a comprehensive view of the subduction zone processes: heat balance, circulation of H2O magmatism–metamorphism, growth of arcs and continental margins. A large scale convection model with steady subduction of a cold old slab (130 Myr old) predicts rapid ( 100 Myr) cooling of subduction zones, resulting in cessation of magmatism. The model also predicts that the mantle temperature beneath arcs and continental margins is greatly affected by the effective temperature of the subducting slab, i.e., the age of the subducting slab. If subduction of a young hot slab, including ridge subduction, occurs every 60 to 120 Myr as is suggested for eastern Asia, the average temperature beneath arcs is increased by about 300 °C, which may explain the long-lasting magmatism in eastern Asia. Associated with subduction of young slabs and ridges, thermal structure and circulation of H2O are greatly modified to cause a transition from (1) normal arc magmatism, (2) forearc mantle melting, to (3) slab melting to produce a significant amount (100 km3) of granitic melts, associated with both high-P/T and low-P/T type metamorphism. The last stage of (3) can result in formation of a granitic batholith belt and a paired metamorphic belts. Synthesis of the numerical models and observations suggest that episodic subduction of young slabs and ridges can explain heat source for generating a large amount of granitic magmas of batholiths, synchronous formation of batholith and regional metamorphic belts, and P–T conditions of the paired metamorphism. Even the high-P/T metamorphism requires an elevated geothermal structure in the forearc region, associated with ridge subduction. Although the emplacement of the batholiths and the regional metamorphic belts, and the mass balance in subduction zones are not well constrained at present, the episodic event associated with ridge subduction is thought to be essential for net growth of arcs and continental margins, as well as for the long-term heat balance in subduction zones. 相似文献
250.
Abstract: The physicochemical environment during the ore formation of the Mozumi skarn-type Pb–Zn–Ag deposit, Kamioka mine, Central Japan is discussed with silicate phase equilibria using calculated phase diagrams. The mineral assemblages, mineral chemistry, and fluid inclusion data are coupled with thermodynamic calculation to estimate the stability fO2–XCO2condition of the mineral assemblages at each ore formation stage. The skarn was approximated by the model system CaO–A12O3–FeO–SiO2–O2–CO2–H2O including grossular-andradite garnet and clinozoisite-epidote solid solutions. The solid solutions are combined into the calculation using "pseudocompound approximation", and real boundary of the mineral assemblages other than simple activity corrected diagram was provided. The diagrams also show isoplethal contour for garnet and epidote. 相似文献