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81.
Geologic Core Holder with a CFR PEEK Body for the X-ray CT-Based Numerical Analysis of Fracture Flow Under Confining Pressure 总被引:1,自引:0,他引:1
82.
Bhadravathi Eswara Lokesh Zubaidah Aimi Abdul Hamid Takamitsu Arai Akihiko Kosugi Yoshinori Murata Rokiah Hashim Othman Sulaiman Yutaka Mori Kumar Sudesh 《洁净——土壤、空气、水》2012,40(3):310-317
Utilization of cheap renewable carbon feedstock for polyhydroxyalkanoate (PHA) production not only brings down its production cost but also ensures sustainability. The scope of this study was to evaluate the potential of sap extracted from felled oil palm trunk (OPT) as a novel inexpensive renewable carbon source for PHA production. OPT sap was found to be nutritionally rich and contained various fermentable sugars (5.5% w/v) as its major constituent. Termite gut isolate, Bacillus megaterium MC1 grew profoundly in mineral medium with OPT sap as carbon source and a cell density of 10.9 g/L was attained after 16 h of cultivation in shake flask cultures. A maximum poly‐3‐hydroxybutyrate [P(3HB)] content (% cell dry weight; CDW) of 30 wt% and a P(3HB) concentration of 3.28 g/L was recorded. Additionally, OPT sap extracted from younger tree trunks with prolonged storage had higher sugar content (10.8% w/v) and, when used as a growth medium without the addition of any nutrients, supported bacterial growth comparable to commercially available media. 相似文献
83.
Zircon U–Pb ages of plutonic rocks in the southern Abukuma Mountains: Implications for Cretaceous geotectonic evolution of the Abukuma Belt
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Yutaka Takahashi Masumi Mikoshiba Kazuya Kubo Hideki Iwano Tohru Danhara Takafumi Hirata 《Island Arc》2016,25(2):154-188
Plutonic rocks in the southern Abukuma Mountains include gabbro and diorite, fine‐grained diorite, hornblende–biotite granodiorite (Ishikawa, Samegawa, main part of Miyamoto and Tabito, Kamikimita and Irishiken Plutons), biotite granodiorite (the main part of Hanawa Pluton and the Torisone Pluton), medium‐ to coarse‐grained biotite granodiorite and leucogranite, based on the lithologies and geological relations. Zircon U–Pb ages of gabbroic rocks are 112.4 ±1.0 Ma (hornblende gabbro, Miyamoto Pluton), 109.0 ±1.1 Ma (hornblende gabbro, the Hanawa Pluton), 102.7 ±0.8 Ma (gabbronorite, Tabito Pluton) and 101.0 ±0.6 Ma (fine‐grained diorite). As for the hornblende–biotite granodiorite, zircon U–Pb ages are 104.2 ±0.7 Ma (Ishikawa Pluton), 112.6 ±1.0 Ma (Tabito Pluton), 105.2 ±0.8 Ma (Kamikimita Pluton) and 105.3±0.8 Ma (Irishiken Pluton). Also for the medium‐ to fine‐grained biotite granodiorite, zircon U–Pb ages are 106.5±0.9 Ma (Miyamoto Pluton), 105.1 ±1.0 Ma (Hanawa Pluton) and the medium‐ to coarse‐grained biotite granodiorite has zircon U–Pb age of 104.5 ±0.8 Ma. In the case of the leucogranite, U–Pb age of zircon is 100.6 ±0.9 Ma. These data indicate that the intrusion ages of gabbroic rocks and surrounding granitic rocks ranges from 113 to 101 Ma. Furthermore, K–Ar ages of biotite and or hornblende in the same rock samples were dated. Accordingly, it is clear that these rocks cooled down rapidly to 300 °C (Ar blocking temperature of biotite for K–Ar system) after their intrusion. These chronological data suggest that the Abukuma plutonic rocks in the southern Abukuma Mountains region uplifted rapidly around 107 to 100 Ma after their intrusion. 相似文献
84.
Yutaka Nakamura Akira Fukukita Kazuo Tamura Issei Yamazaki Taichi Matsuoka Kazuhiko Hiramoto Katsuaki Sunakoda 《地震工程与结构动力学》2014,43(4):507-527
This paper presents a new type of electromagnetic damper with rotating inertial mass that has been developed to control the vibrations of structures subjected to earthquakes. The electromagnetic inertial mass damper (EIMD) consists of a ball screw that converts axial oscillation of the rod end into rotational motion of the internal flywheel and an electric generator that is turned by the rotation of the inner rod. The EIMD is able to generate a large inertial force created by the rotating flywheel and a variable damping force developed by the electric generator. Device performance tests of reduced‐scale and full‐scale EIMDs were undertaken to verify the basic characteristics of the damper and the validity of the derived theoretical formulae. Shaking table tests of a three‐story structure with EIMDs and earthquake response analyses of a building with EIMDs were conducted to demonstrate the seismic response control performance of the EIMD. The EIMD is able to reduce story drifts as well as accelerations and surpasses conventional types of dampers in reducing acceleration responses. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
85.
Rapid decrease of mass balance observed in the Xiao (Lesser) Dongkemadi Glacier,in the central Tibetan Plateau 总被引:1,自引:0,他引:1
Jianchen Pu Tandong Yao Meixue Yang Lide Tian Ninlian Wang Yutaka Ageta Koji Fujita 《水文研究》2008,22(16):2953-2958
The mass balance of the Xiao (Lesser) Dongkemadi Glacier located in the Tanggula Mountains, of the central Qinghai‐Tibetan Plateau has been monitored since 1989. The results show that the mass balance of the glacier has recently shown a deficit trend, and that the glacial terminus was also retreating. Positive mass balance of the glacier was dominant during the period 1989–1993, and the accumulated mass balance reached 970 mm. However, negative mass balance of the glacier has occurred since 1994, except for the large positive mass balance year 1997. The mass balance was ? 701 mm in 1998, an extremely negative glacier mass balance year. The equilibrium line altitude showed a significant increasing trend. The mass balance of the glacier has changed from a significantly positive mass balance to a strongly negative mass balance since 1994. Meteorological data suggest that the rapid decrease in the mass balance is related to summer season warming. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
86.
Alexey A. Krylov Oleg M. Khlystov Akihiro Hachikubo Hirotsugu Minami Yutaka Nunokawa Hitoshi Shoji Tamara I. Zemskaya Lieven Naudts Tatyana V. Pogodaeva Masato Kida Gennady V. Kalmychkov Jeffrey Poort 《Geo-Marine Letters》2010,30(3-4):427-437
We report on the isotopic composition of dissolved inorganic carbon (DIC) in pore-water samples recovered by gravity coring from near-bottom sediments at gas hydrate-bearing mud volcanoes/gas flares (Malenky, Peschanka, Peschanka 2, Goloustnoe, and Irkutsk) in the Southern Basin of Lake Baikal. The δ13C values of DIC become heavier with increasing subbottom depth, and vary between ?9.5 and +21.4‰ PDB. Enrichment of DIC in 13C indicates active methane generation in anaerobic environments near the lake bottom. These data confirm our previous assumption that crystallization of carbonates (siderites) in subsurface sediments is a result of methane generation. Types of methanogenesis (microbial methyl-type fermentation versus CO2-reduction) were revealed by determining the offset of δ13C between dissolved CH4 and CO2, and also by using δ13C and δD values of dissolved methane present in the pore waters. Results show that both mechanisms are most likely responsible for methane generation at the investigated locations. 相似文献
87.
Takamitsu Yamanaka Yutaka Komatsu Hironori Nomori 《Physics and Chemistry of Minerals》2007,34(5):307-318
Many of ilmenites ABO3 compounds bearing transition elements have semiconductive, ferroelectric and antiferromagnetic properties. The high-pressure
diffraction studies of FeTiO3 have been conducted up to 8.2 GPa using synchrotron radiation in KEK at Tsukuba with diamond anvil cell. The compression
mechanism of FeTiO3 ilmenite has been investigated by the structure refinements converged to the reliable factors R = 0.05. The deformations of the FeO6 and TiO6 octahedra were reduced with increasing pressure. In order to elucidate the electric conductivity change with pressure, electron
density distribution of ilmenite have been executed by maximum entropy method (MEM) using single-crystal diffraction intensity
data. MEM based on F
obs(hkl) of FeTiO3 clearly shows electron density in comparison with the difference Fourier synthesis based on F
obs(hkl) − F
calc(hkl). The radial distribution of the electron density indicates electron localization around the cation positions. The bonding
electron density found in bond Fe–O and Ti–O is lowered with pressure. The isotropic temperature factors B
iso become smaller with increasing pressure. Nevertheless the thermal vibration is considerably restrained by the compression,
the electric conductivity is enhanced with pressure. Neither charge transfer nor electron hopping between Fe and Ti along
the c axis in FeTiO3 is plausible under high pressure. But the electric conductivity due to electron super-exchange in Fe–Fe and Ti–Ti has been
clarified by the MEM electron density distribution. The anisotropy in the electric conductivity has been clarified. 相似文献
88.
Sedimentary inorganic nitrogen and its isotope ratio in the western subarctic Pacific over the last 145 kyr 总被引:1,自引:0,他引:1
We have measured inorganic nitrogen (IN) content and the isotope ratio of IN (δ15NIN) in a sediment core covering the last 145 kyr in the western subarctic Pacific (WSAP). IN content was generally high during
glacial periods and shows positive correlations with both eolian dust content and the ratio of organic carbon (C) to organic
nitrogen (ON) (C/ON) found in our previous studies. This means that IN was transported from continental areas to the WSAP
together with eolian dust and that the IN was not contaminated by volcanic materials, because the eolian dust content was
reconstructed using metal components to remove contaminating volcanic materials. Therefore, IN content in the WSAP sediments,
the clay fraction of which is not greatly affected by drift deposits seen at the other sites in this region, may potentially
be an effective proxy for eolian dust, without the need to consider contamination by volcanic materials. δ15NIN was generally low during glacial periods and shows negative correlations with IN, eolian dust, and C/ON. The possible causes
of the observed variations in δ15NIN are as follows: (1) authigenic fixation of NH4
+ in water-column and pore water of sea-floor sediments to clay minerals; (2) contamination of measured IN by highly resistant
organic matter; or (3) variations in the continental source region of the eolian dust supplied to the WSAP and climatically
induced changes in δ15N of soil organic matter there. The last mechanism shows the potential for δ15NIN to be used as a proxy for climate change on land, and is consistent with other published explanations of the spatial distribution
of δ15NIN in modern sea-floor sediments. 相似文献
89.
Yutaka?W.?WatanabeEmail author Hiroshi?Ishida Toshiya?Nakano Naoki?Nagai 《Journal of Oceanography》2005,61(6):1011-1016
Using time series of hydrographic data in the wintertime and summertime obtained along 137°E from 1971 to 2000, we found that
the average contents of nutrients in the surface mixed layer showed linear decreasing trends of 0.001∼0.004 μmol-PO4 l−1 yr−1 and 0.01∼0.04 μmol-NO3 l−1 yr−1 with the decrease of density. The water column Chl-a (CHL) and the net community production (NCP) had also declined by 0.27∼0.48
mg-Chl m−2 yr−1 and 0.08∼0.47 g-C-NCP m−2 yr−1 with a clear oscillation of 20.8±0.8 years. These changes showed a strong negative correlation with the Pacific Decadal Oscillation
Index (PDO) with a time lag of 2 years (R = 0.89 ± 0.02). Considering the recent significant decrease of O2 over the North Pacific subsurface water, these findings suggest that the long-term decreasing trend of surface-deep water
mixing has caused the decrease of marine biological activity in the surface mixed layer with a bidecadal oscillation over
the western North Pacific. 相似文献
90.
Harutaka Sakai Minoru Sawada Yutaka Takigami Yuji Orihashi Tohru Danhara Hideki Iwano Yoshihiro Kuwahara Qi Dong Huawei Cai Jianguo Li 《Island Arc》2005,14(4):297-310
Abstract Newly discovered peloidal limestone from the summit of Mount Qomolangma (Mount Everest) contains skeletal fragments of trilobites, ostracods and crinoids. They are small pebble-sized debris interbedded in micritic bedded limestone of the Qomolangma Formation, and are interpreted to have been derived from a bank margin and redeposited in peri-platform environments. An exposure of the Qomolangma detachment at the base of the first step (8520 m), on the northern slope of Mount Qomolangma was also found. Non-metamorphosed, strongly fractured Ordovician limestone is separated from underlying metamorphosed Yellow Band by a sharp fault with a breccia zone. The 40 Ar–39 Ar ages of muscovite from the Yellow Band show two-phase metamorphic events of approximately 33.3 and 24.5 Ma. The older age represents the peak of a Barrovian-type Eo-Himalayan metamorphic event and the younger age records a decompressional high-temperature Neo-Himalayan metamorphic event. A muscovite whole-rock 87 Rb–86 Sr isochron of the Yellow Band yielded 40.06 ± 0.81 Ma, which suggests a Pre-Himalayan metamorphism, probably caused by tectonic stacking of the Tibetan Tethys sediments in the leading margin of the Indian subcontinent. Zircon and apatite grains, separated from the Yellow Band, gave pooled fission-track ages of 14.4 ± 0.9 and 14.4 ± 1.4 Ma, respectively. These new chronologic data indicate rapid cooling of the hanging wall of the Qomolangma detachment from approximately 350°C to 130°C during a short period (15.5–14.4 Ma). 相似文献