Oblique and near collision subduction, Sagami and Suruga Troughs —preliminary results of the French-Japanese 1984 Kaiko cruise, Leg 2     

Kazuaki Nakamura  Vincent Renard  Jacques Angelier  Jacques Azema  Jacques Bourgois  Christine Deplus  Kantaro Fujioka  Yozo Hamano  Philippe Huchon  Hajimu Kinoshita  Pierre Labaume  Yujiro Ogawa  Tetsuzo Seno  Akira Takeuchi  Manabu Tanahashi  Akinori Uchiyama  Jean-Louis Vigneresse 《Earth and Planetary Science Letters》1987,83(1-4)

Leg 2 of the French-Japanese 1984 Kaiko cruise has surveyed the Suruga and the Sagami Troughs, which lie on both sides of the northwestward moving and colliding Izu-Bonin Ridge, the northernmost part of the Philippine Sea plate. The transition from the Nankai Trough to the Suruga Trough is characterized by northward decrease in width of the accretionary prism, in good agreement with the increasing obliquity between the through axis and the direction of the convergence, as the strike of the convergent boundary changes from ENE-NNE to south-north. South of the area, the southern margin of the Zenisu Ridge shows contractional deformations. This supports the interpretation made by the team of Leg 1 who studied the western extension of the area we studied, that it is an intra-oceanic thrusting of the ridge over the Shikoku Basin. In the Sagami Trough, where the relative motion is highly oblique to the plate boundary, active subduction is mostly confined in the east-west trending portions of the trough located south of the Boso Peninsula and along the lower Boso Canyon, near the TTT triple junction. In between, the present motion is mainly right-lateral along the northwest trending Boso escarpment. However, an inactive but recent (Pliocene to lower Pleistocene) accretionary prism exists south of the Boso escarpment, which suggests that the relative motion was more northerly than at present before about 1 Ma ago.  相似文献   

Vortex structures around a hemispheric hump     

Nobuyuki Tamai  Takashi Asaeda  Norio Tanaka 《Boundary-Layer Meteorology》1987,39(3):301-314

The vortex structure formed in front of and behind a hemispheric surface hump has been studied in a water recirculating flume. In the recirculation zone behind the hemisphere, arched vortex tubes were formed. Up to a certain critical Reynolds number, each tube was shed individually from the recirculation zone. However, when the Reynolds number exceeded a critical value, several of the tubes coalesced in the recirculation zone before shedding. In front of the hemisphere, some parabolic vortex tubes formed. Their number increased with Reynolds number below its critical value and decreased above this value. The dimensionless height of the parabolic vortex tube decreased with Reynolds number.  相似文献   

Multiobjective heuristic approaches to seismic design of steel frames with standard sections     

M. Ohsaki  T. Kinoshita  P. Pan 《地震工程与结构动力学》2007,36(11):1481-1495

Seismic design problem of a steel moment‐resisting frame is formulated as a multiobjective programming problem. The total structural (material) volume and the plastic dissipated energy at the collapse state against severe seismic motions are considered as performance measures. Geometrically nonlinear inelastic time‐history analysis is carried out against recorded ground motions that are incrementally scaled to reach the predefined collapse state. The frame members are chosen from the lists of the available standard sections. Simulated annealing (SA) and tabu search (TS), which are categorized as single‐point‐search heuristics, are applied to the multiobjective optimization problem. It is shown in the numerical examples that the frames that collapse with uniform interstorey drift ratios against various levels of ground motions can be obtained as a set of Pareto optimal solutions. Copyright © 2007 John Wiley & Sons, Ltd.  相似文献   

The stabilising mechanism of the HD 82943 planetary system     

Jiang-hui Ji  Lin Liu  Kinoshita H.  Nakai H. 《Chinese Astronomy and Astrophysics》2002,26(4):75-385

We carry out simulations to investigate the dynamics of the HD 82943 planetary system with two resonant Jupiter-like planets, and to reveal possible stabilizing mechanism for the system. By following different coplanar configurations in the neighborhood of the best-fit orbits, we find that all the stable cases are involved in the 2:1 mean motion resonance and that the alignment of the periastra of the two planets also plays important part in the secular orbital evolution, indicating that these two kinds of mechanisms could be responsible for the dynamics of the system under study.  相似文献   

Effects of motion of the equatorial plane on the orbital elements of an earth satellite   总被引：1，自引：0，他引：1  

Yoshihide Kozai  Hiroshi Kinoshita 《Celestial Mechanics and Dynamical Astronomy》1973,7(3):356-366

Exact differential equations relating the perturbations to satellite orbital elements by the motion of the Earth's equatorial plane are derived, and they are solved to second order in precession. The system proposed in a previous paper (Kozai, 1960), in which the inclination and the argument of perigee are referred to the equator of date and the longitude of the ascending node is measured from a fixed point along a fixed plane and then along the equator of date, can still be recommended for precise studies of satellite motion even when the second-order perturbations are taken into account.  相似文献   

A note on expansions of functions of velocity in the two-body problem     

Hiroshi Kinoshita 《Celestial Mechanics and Dynamical Astronomy》1977,15(4):501-505

Fourier expansions of functions of velocity in the two-body problem are obtained in terms of both the true anomaly and the mean anomaly.  相似文献   

Specific accumulation and temporal trends of organochlorine contaminants in Dall's porpoises (Phocoenoides dalli) from Japanese coastal waters     

Kajiwara N  Watanabe M  Tanabe S  Nakamatsu K  Amano M  Miyazaki N 《Marine pollution bulletin》2002,44(10):1089-1099

Organochlorine compounds (OCs) such as polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroethane and its metabolites (DDTs), chlordane related compounds, hexachlorocyclohexane isomers (HCHs), hexachlorobenzene (HCB), tris(4-chlorophenyl) methane (TCPMe) and tris(4-chlorophenyl) methanol were determined in the blubber of Dall's porpoises (Phocoenoides dalli) collected from Japanese coastal waters in 1998/1999. Among OCs analyzed, PCBs were the predominant contaminants with concentrations ranging from 1.5 to 39 microg/g on a wet weight basis. OCs concentrations were relatively low and less variable in mature females possibly due to the lactational excretion from their bodies, while in males the concentrations were increased with body length. Concentrations and compositions of DDTs and HCHs showed significant differences between the truei-type population off the Pacific coast of northern Japan and dalli-type from the Sea of Japan/Okhotsk, suggesting its usefulness to discriminate different populations. OCs levels detected in truei-type porpoises collected in 1998/1999 were lower than those collected in 1984, except TCPMe. On the other hand, except DDTs, the residue levels of other organochlorines in dalli-type porpoises showed no significant decrease since 1984.  相似文献   

New radioisotope-free method for measuring bacterial production using [15N5]-2′-deoxyadenosine and liquid chromatography mass spectrometry (LC–MS) in aquatic environments     

Kenji Tsuchiya  Tomoharu Sano  Nobuyuki Kawasaki  Hideki Fukuda  Noriko Tomioka  Koji Hamasaki  Yuya Tada  Shinji Shimode  Tatsuki Toda  Akio Imai 《Journal of Oceanography》2015,71(6):675-683

  相似文献   

An emission pathway for stabilization at 6?Wm?2 radiative forcing   总被引：1，自引：0，他引：1  

Toshihiko Masui  Kenichi Matsumoto  Yasuaki Hijioka  Tsuguki Kinoshita  Toru Nozawa  Sawako Ishiwatari  Etsushi Kato  P. R. Shukla  Yoshiki Yamagata  Mikiko Kainuma 《Climatic change》2011,109(1-2):59-76

Representative Concentration Pathway 6.0 (RCP6) is a pathway that describes trends in long-term, global emissions of greenhouse gases (GHGs), short-lived species, and land-use/land-cover change leading to a stabilisation of radiative forcing at 6.0 Watts per square meter (Wm^?2) in the year 2100 without exceeding that value in prior years. Simulated with the Asia-Pacific Integrated Model (AIM), GHG emissions of RCP6 peak around 2060 and then decline through the rest of the century. The energy intensity improvement rates changes from 0.9% per year to 1.5% per year around 2060. Emissions are assumed to be reduced cost-effectively in any period through a global market for emissions permits. The exchange of CO₂ between the atmosphere and terrestrial ecosystem through photosynthesis and respiration are estimated with the ecosystem model. The regional emissions, except CO₂ and N₂O, are downscaled to facilitate transfer to climate models.  相似文献   

Temporal alteration of fracture permeability in granite under hydrothermal conditions and its interpretation by coupled chemo-mechanical model     

Hide Yasuhara  Naoki Kinoshita  Hiroaki Ohfuji  Dae Sung Lee  Shinichiro Nakashima  Kiyoshi Kishida 《Applied Geochemistry》2011,26(12):2074-2088

Examining the evolution of fracture permeability under stressed and temperature-elevated conditions, a series of flow-through experiments on a single rock fracture in granite has been conducted under confining pressures of 5 and 10 MPa, under differential water pressures ranging from 0.04 to 0.5 MPa, and at temperatures of 20–90 °C, for several hundred hours in each experiment. Measurements of fluid and dissolved mass fluxes, and post-experimental microscopy, were conducted to constrain the progress of mineral dissolution and/or precipitation and to examine its effect on transport properties. Generally, the fracture aperture monotonically decreased with time at room temperature, and reached a steady state in relatively short periods (i.e., <400 h). However, once the temperature was elevated to 90 °C, the aperture resumed decreasing and kept decreasing throughout the rest of the experimental periods. This reduction may result from the removal of the mineral mass from the bridging asperities within the fracture. Post-experimental observations by scanning electron microscopy, coupled with energy dispersive X-ray spectroscopy (SEM-EDX), revealed the formation of several kinds of secondary minerals such as silica and calcite. However, the precipitated minerals seemed to have had little influence on the flow characteristics within the fracture, because the precipitation was limited to quite local and small areas. The evolving rates and ultimate magnitudes of the fracture aperture are likely to be controlled by the stress exerted over the contacting asperities and temperatures, and by the prescribed flow conditions. Thus, this complex behavior should be attributed to the coupled chemically- and mechanically-induced effect. A coupled chemo–mechano conceptual model, accounting for pressure and free-face dissolutions, is presented in this paper to follow the evolution of the fracture permeability observed in the flow-through experiments. This model addresses the two dissolution processes at the contacting asperities and the free walls within the fractures, and is also capable of describing multi-mineral dissolution behavior. The model shows that the evolution of a fracture aperture (or related permeability) and of element concentrations may be followed with time under arbitrary temperature and pressure conditions. The model predictions for the evolving fracture aperture and elements concentrations show a relatively good agreement with the experimental measurements, although it is not possible to replicate the abrupt reduction observed in the early periods of the experiments, which is likely to be due to an unaccounted mechanism of more stress-mediated fracture compaction driven by the fracturing of the propping asperities.  相似文献