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51.
Xinyu Jiang Nobuhito Mori Hirokazu Tatano Lijiao Yang Yoko Shibutani 《Natural Hazards》2016,84(1):35-53
This paper estimates property loss and business interruption loss under scenarios of storm surge inundation to explore the economic impact of climate change on Ise Bay, Japan. Scenarios-based analyses are conducted with respect to Typhoon Vera, which caused the most severe storm surge in the recorded history of Japan in 1959. Four different hazard scenarios are chosen from a series of typhoon storm surge inundation simulations: Typhoon Vera’s landfall with respect to the condition of the past seawall; Typhoon Vera’s landfall with respect to the condition of the current seawall; intensifying Typhoon Vera, but retaining its original tracks; and intensifying Typhoon Vera, but choosing the worst tracks from various possible typhoon tracks. Our economic loss estimation takes advantage of fine geographical scale census and economic census data that enable us to understand the spatial distribution of property loss and business interruption loss as well as identify the most potentially affected areas and business sectors on a sub-city scale. By comparing the property loss and business interruption loss caused by different hazard scenarios, the effect of different seawalls is evaluated and the economic impact of future climate change is estimated. The results indicate that although the current seawall can considerably reduce the scale of losses, climate change can cause Ise Bay to experience more serious storm surge inundation. Moreover, the resulting economic losses would increase significantly owing to a combination of climate change and the worst track scenario. It is, therefore, necessary to consider more countermeasures to adapt to climate change in this area. 相似文献
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54.
Hirokazu Yoshimura 《Journal of Astrophysics and Astronomy》2000,21(3-4):365-371
We briefly describe historical development of the concept of solar dynamo mechanism that generates electric current and magnetic
field by plasma flows inside the solar convection zone. The dynamo is the driver of the cyclically polarity reversing solar
magnetic cycle. The reversal process can easily and visually be understood in terms of magnetic field line stretching and
twisting and folding in three-dimensional space by plasma flows of differential rotation and global convection under influence
of Coriolis force. This process gives rise to formation of a series of huge magnetic flux tubes that propagate along iso-rotation
surfaces inside the convection zone. Each of these flux tubes produces one solar cycle. We discuss general characteristics
of any plasma flows that can generate magnetic field and reverse the polarity of the magnetic field in a rotating body in
the Universe. We also mention a list of problems which are currently being disputed concerning the solar dynamo mechanism
together with observational evidences that are to be constraints as well as verifications of any solar cycle dynamo theories
of short and long term behaviors of the Sun, particularly time variations of its magnetic field, plasma flows, and luminosity. 相似文献
55.
A rate‐dependent constitutive model of high damping rubber bearings: modeling and experimental verification 下载免费PDF全文
Yong Yuan Wei Wei Ping Tan Akira Igarashi Hongping Zhu Hirokazu Iemura Tetsuhiko Aoki 《地震工程与结构动力学》2016,45(11):1875-1892
In this study, a constitutive model of high damping rubber bearings (HDRBs) is developed that allows the accurate representation of the force–displacement relationship including rate‐dependence for shear deformation. The proposed constitutive model consists of two hyperelastic springs and a nonlinear dashpot element and expresses the finite deformation viscoelasticity laws based on the classical Zener model. The Fletcher–Gent effect, manifested as high horizontal stiffness at small strains and caused by the carbon fillers in HDRBs, is accurately expressed through an additional stiffness correction factor α in the novel strain energy function. Several material parameters are used to simulate the responses of high damping rubber at various strain levels, and a nonlinear viscosity coefficient η is introduced to characterize the rate‐dependent property. A parameter identification scheme is applied to the results of the multi‐step relaxation tests and the cyclic shear tests, and a three‐dimensional function of the nonlinear viscosity coefficient η with respect to the strain, and strain rate is thus obtained. Finally, to investigate the accuracy and feasibility of the proposed model for application to the seismic response assessment of bridges equipped with HDRBs, an improved real‐time hybrid simulation (RTHS) test system based on the velocity loading method is developed. A single‐column bridge was used as a test bed and HDRBs was physically tested. Comparing the numerical and RTHS results, advantage of the proposed model in the accuracy of the predicted seismic response over comparable hysteretic models is demonstrated. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
56.
Biotite dissolution experiments were carried out to better understand the dissolution kinetics and Fe behavior under low O2 conditions, and to give an insight into the Precambrian weathering. Mineral dissolution with a continuous flow-through reactor was employed at 25 °C for up to 65 days varying partial pressure of atmospheric oxygen (PO2), pH (6.86 and 3.01) and Fe content in mineral (1.06 and 0.11 mol of Fe per O10(OH,F)2 for biotite and phlogopite, respectively) independently for the examination of their effects on biotite dissolution. Low PO2 conditions were achieved in a newly developed glove box (PO2 ? 6 × 10−4 atm; referred to as anoxic conditions), which was compared to the present, ambient air conditions (0.2 atm of PO2; oxic conditions). The biotite dissolution rate was slightly faster under anoxic conditions at pH 6.86 while it was not affected by PO2 at pH 3.01. There was no direct effect of Fe content on dissolution rate at pH 6.86 while there was a small difference in dissolution rate between biotite and phlogopite at pH 3.01. The 1.5 order-of-magnitude faster release rate of Fe under anoxic conditions for biotite dissolution at pH 6.86 resulted from the difference in ratio of Fe3+ precipitates remaining in the reactor to Fe dissolved (about 60% and 100% under anoxic and oxic conditions, respectively), which is caused mainly by the difference in PO2. The results infer that the Fe2+ and Fe3+ contents in the Paleoproterozoic paleosols, fossil weathering profiles, are reflected by atmospheric oxygen levels at the time of weathering. 相似文献
57.
Hirokazu Iemura Touraj Taghikhany Yoshikazu Takahashi Sarvesh K. Jain 《地震工程与结构动力学》2005,34(15):1777-1797
In this study, a series of shaking table tests are carried out on scaled models of two seismically isolated highway bridges to investigate the effect of rocking motion and vertical acceleration on seismic performance of resilient sliding isolators. In addition, performance of RSI is compared with system having solely natural rubber bearings. Test results show that variation of normal force on sliders due to rocking effect and vertical acceleration makes no significant difference in response of RSI systems. In addition, analytical response of prototype isolated bridge and the model used in experiments is obtained analytically by using non‐linear model for isolation systems. It is observed that for seismically isolated bridges, dynamic response of full‐scale complex structures can be predicted with acceptable accuracy by experiments using a simple model of the structure. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
58.
Samaddar Subhajyoti Choi Junho Misra Bijay Anand Tatano Hirokazu 《Natural Hazards》2015,75(2):1531-1554
Natural Hazards - Recent decades have seen an increasing recognition and consensus among researchers and planners in disaster management in the need to foster social learning... 相似文献
59.
Dávid Karátson Jean-Claude Thouret Ichio Moriya Alejandro Lomoschitz 《Bulletin of Volcanology》1999,61(3):174-193
The origin and development of erosion-modified, erosion-transformed, and erosion-induced depressions in volcanic terrains
are reviewed and systematized. A proposed classification, addressing terminology issues, considers structural, geomorphic,
and climatic factors that contribute to the topographic modification of summit or flank depressions on volcanoes. Breaching
of a closed crater or caldera generated by volcanic or non-volcanic processes results in an outlet valley. Under climates
with up to ∼2000–2500 mm annual rainfall, craters, and calderas are commonly drained by a single outlet. The outlet valley
can maintain its dominant downcutting position because it quickly enlarges its drainage basin by capturing the area of the
primary depression. Multi-drained volcanic depressions can form if special factors, e.g., high-rate geological processes,
such as faulting or glaciation, suppress fluvial erosion. Normal (fluvial) erosion-modified volcanic depressions the circular
rim of which is derived from the original rim are termed erosion craters or erosion calderas, depending on the pre-existing
depression. The resulting landform should be classed as an erosion-induced volcanic depression if the degradation of a cluster
of craters produces a single-drained, irregular-shaped basin, or if flank erosion results in a quasi-closed depression. Under
humid climates, craters and calderas degrade at a faster rate. Mostly at subtropical and tropical ocean-island and island-arc
volcanoes, their erosion results in so-called amphitheater valleys that develop under heavy rainfall (>∼2500 mm/year), rainstorms,
and high-elevation differences. Structural and lithological control, and groundwater in ocean islands, may in turn preform
and guide development of high-energy valleys through rockfalls, landsliding, mudflows, and mass wasting. Given the intense
erosion, amphitheater valleys are able to breach a primary depression from several directions and degrade the summit region
at a high rate. Occasionally, amphitheater valleys may create summit depressions without a pre-existing crater or caldera.
The resulting, negative landforms, which may drain in several directions and the primary origin of which is commonly unrecognizable,
should be included in erosion-transformed volcanic depressions.
Received: 4 January 1998 / Accepted: 18 January 1999 相似文献
60.
Solar Physics - A new concept concerning sunspot cooling and X-ray bright point heating is presented. Sunspot and X-ray bright point small scale flux ropes detach from global scale solar cycle main... 相似文献