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1.
Shin-Ichi Machida Hisako Hirai Taro Kawamura Yoshitaka Yamamoto Takehiko Yagi 《Physics and Chemistry of Minerals》2007,34(1):31-35
High-pressure Raman studies of methane hydrate were performed using a diamond anvil cell in the pressure range of 0.1–86 GPa
at room temperature. Raman spectra of the methane molecules revealed that new softened intramolecular vibration mode of ν
1 appeared at 17 GPa and that the splitting of vibration mode of ν
3 occurred at 15 GPa. The appearance of these two modes indicates that an intermolecular attractive interaction increases between
the methane molecules and the host water molecules and between the neighboring methane molecules. These interactions might
result in the exceptional stability of a high-pressure structure, a filled ice Ih structure (FIIhS) for methane hydrate, up
to 40 GPa. At 40 GPa, a clear change in the slope of the Raman shift versus pressure occurred, and above 40 GPa the Raman
shift of the vibration modes increased monotonously up to 86 GPa. A previous XRD study showed that the FIIhS transformed into
another new high-pressure structure at 40 GPa. The change in the Raman spectra at 40 GPa may be induced by the transition
of the structure. 相似文献
2.
Abstract. Near-infrared (NIR) and visible light microthermometry was applied to the fluid inclusions in sphalerite from a possible southeast extension of the Toyoha polymetallic deposit. Sphalerite occurs as euhedral-subhedral crystals or collo-form aggregates with a variety of color, which contain a well-developed growth banding. Combined with morphological observations, fluid inclusions in dark-colored sphalerite were examined using a near-infrared light microscopic technique, whereas those in light-colored sphalerite and quartz were examined by a conventional visible light microscopy.
Salinities of fluid inclusions in dark-colored sphalerite have a wide variation (1.0–10.3 wt % NaCl equiv.) compared to that in light-colored sphalerite and quartz (0.0–3.4 wt % NaCl equiv.). These variations suggest that the conventional microthermometric data from light-colored sphalerite and quartz were inadequate to interpret the ore formation process. Dark-colored colloform sphalerite and a dark core of subhedral sphalerite formed from high-salinity fluids (6.5–10.3 wt % NaCl equiv.) under highly supersaturated conditions with respect to sphalerite.
The NIR and visible light microthermometry of fluid inclusions in sphalerite combined with its morphological observations is an invaluable method to infer the formation conditions of sphalerite. The NIR and visible light microthermometry is useful to reveal how the nature of ore fluids changed with time. 相似文献
Salinities of fluid inclusions in dark-colored sphalerite have a wide variation (1.0–10.3 wt % NaCl equiv.) compared to that in light-colored sphalerite and quartz (0.0–3.4 wt % NaCl equiv.). These variations suggest that the conventional microthermometric data from light-colored sphalerite and quartz were inadequate to interpret the ore formation process. Dark-colored colloform sphalerite and a dark core of subhedral sphalerite formed from high-salinity fluids (6.5–10.3 wt % NaCl equiv.) under highly supersaturated conditions with respect to sphalerite.
The NIR and visible light microthermometry of fluid inclusions in sphalerite combined with its morphological observations is an invaluable method to infer the formation conditions of sphalerite. The NIR and visible light microthermometry is useful to reveal how the nature of ore fluids changed with time. 相似文献
3.
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
4.
5.
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
6.
Stable carbon isotope distribution of particulate organic matter in the ocean: a model study 总被引:4,自引:0,他引:4
Matthias Hofmann Dieter A. Wolf-Gladrow Taro Takahashi Steward C. Sutherland Katharina D. Six Ernst Maier-Reimer 《Marine Chemistry》2000,72(2-4)
The stable carbon isotopic composition of particulate organic matter in the ocean, δ13CPOC, shows characteristic spatial variations with high values in low latitudes and low values in high latitudes. The lowest δ13CPOC values (−32‰ to −35‰) have been reported in the Southern Ocean, whereas in arctic and subarctic regions δ13CPOC values do not drop below −27‰. This interhemispheric asymmetry is still unexplained. Global gradients in δ13CPOC are much greater than in δ13CDIC, suggesting that variations in isotopic fractionation during organic matter production are primarily responsible for the observed range in δ13CPOC. Understanding the factors that control isotope variability is a prerequisite when applying δ13CPOC to the study of marine carbon biogeochemistry. The present model study attempts to reproduce the δ13CPOC distribution pattern in the ocean. The three-dimensional (3D) Hamburg Model of the Oceanic Carbon Cycle version 3.1 (HAMOCC3.1) was combined with two different parametrizations of the biological fractionation of stable carbon isotopes. In the first parametrization, it is assumed that the isotopic fractionation between CO2 in seawater and the organic material produced by algae, P, is a function of the ambient CO2 concentration. The two parameters of this function are derived from observations and are not based on an assumption of any specific mechanism. Thus, this parametrization is purely empirical. The second parametrization is based on fractionation models for microalgae. It is supported by several laboratory experiments. Here the fractionation, P, depends on the CO2 concentration in seawater and on the (instantaneous) growth rates, μi, of the phytoplankton. In the Atlantic Ocean, where most field data are available, both parametrizations reproduce the latitudinal variability of the mean δ13CPOC distribution. The interhemispheric asymmetry of δ13CPOC can mostly be attributed to the interhemispheric asymmetry of CO2 concentration in the water. However, the strong seasonal variations of δ13CPOC as reported by several authors, can only be explained by a growth rate-dependent fractionation, which reflects variations in the cellular carbon demand. 相似文献
7.
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
8.
Shahidul Islam Md. Manabu Hibino Taro Ohta Kouji Nakayama Masaru Tanaka 《Estuaries and Coasts》2006,29(3):519-529
Larval and juvenile Japanese temperate bass (Lateolabrax japonicus) samples were collected from a wide range of spatial gradients (covering a distance of approximately 30 km) in Chikugo estuary,
Ariake Bay, Japan over a period of 8 yr (1997–2004) in order to observe changes in diet. Gut contents were studied by separating,
identifying, counting, and estimating the dry weight of prey organisms. Copepod samples were collected during each cruise
to observe the numerical composition, abundance, and biomass in the estuary. Considerable spatial and temporal variations
were observed in copepod distributions in ambient water and the diets of the fish. Two distinctly different copepod assemblages
were identified in the estuary: One in the upper estuarine turbidity maximum (ETM), dominated by a single speciesSinocalanus sinensis and the other in the lower estuary consisting of a multispecies assemblage, dominated byOithona davisae, Acartia omorii, Paracalanus parvus, andCalanus sinicus. The gut content composition of the fish in the upper estuary was dominated byS. sinensis, while in the lower estuary, it consisted ofP. parvus, O. davisae, andA. omorii. Within the size group analyzed (13.0–27.0 mm SL), the smaller individuals were found to feed on a mixed diet composed of
smaller prey. The diets gradually shifted to bigger prey composed predominantly ofS. sinensis for larger size groups. Greater proportions of empty guts were recorded in the smaller individuals and dropped with increasing
fish size. Higher dry biomass of copepods in the environment, as well as higher dry weights of gut contents, were recorded
in the upper estuary, indicating that the upper estuarine ETM areas are important nursery grounds for the early life stages
of the Japanese temperate bass. The early life stages of the Japanese temperate bass are adapted to use the upstream nursery
grounds and ascending to the nursery areas to useS. sinensis is one of the key survival strategies of the Japanese temperate bass in the Chikugo estuary. 相似文献
9.
Landslides - Used to reduce damage from rainfall-induced landslides and establish disaster-warning systems, physically based stability models are efficient tools for evaluating spatial or temporal... 相似文献
10.
Simple monitoring method for precaution of landslides watching tilting and water contents on slopes surface 总被引:2,自引:2,他引:0
Taro Uchimura Ikuo Towhata Trinh Thi Lan Anh Jou Fukuda Carlos J. B. Bautista Lin Wang Ichiro Seko Taro Uchida Akira Matsuoka Yosuke Ito Yuichi Onda Sho Iwagami Min-Seok Kim Naoki Sakai 《Landslides》2010,7(3):351-357
A low-cost and simple monitoring method for early warning of landslides is proposed. To detect abnormal deformation of a slope, this method employs a tilt sensor in place of an extensometer on the slope surface. In order to examine the relevance of measuring rotation angle on a slope surface by tilt sensor, model tests were conducted, and rotation on the slope surface was observed together with slide displacement along the surface. The rotation data responded 30 min before failure in a model test, which could be useful as a signal for early warning. However, the behavior of rotation before failure varies from case to case, and thus, criteria to issue warning should be defined more carefully. For a model slope made of uniform loose sand, measurement of slide displacement along the slope surface is sensitive to failure at the toe, while the measurement of rotation on the slope surface is useful to detect the development of progressive failure upward along the slope. Wireless sensor units with microelectromechanical systems (MEMS) tilt sensor and volumetric water content sensor were also examined on a real slope in Kobe City, and a long-term monitoring was attempted. A simple but possible way to define the criteria of judgment to issue warning can be proposed based on combination of data obtained by the tilt sensors and volumetric water content sensors. 相似文献