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Ｃｒｕｓｔａｌｓｔｒｕｃｔｕｒｅａｎｄａｃｃｕｒａｔｅｈｙｐｏｃｅｎｔｅｒｄｅ┐ｔｅｒｍｉｎａｔｉｏｎａｌｏｎｇｔｈｅＬｏｎｇｍｅｎｓｈａｎｆａｕｌｔｚｏｎｅＺＨＵＺＨＡＯ１）（赵珠）ＪＵＮＦＡＮ１）（范军）ＳＩ－ＨＵＡＺＨＥＮＧ２）（郑斯华）ＡＫ... 相似文献
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The point at issue: The Kurosegawa Terrane is composed of continental fragments transecting Mesozoic terranes of accretionary complex in Southwest Japan (Fig. 1). It is an attenuated tectonic sliver and considered to be allochthonous with respect to the main part of Southwest Japan. The problem of which continental block in the East Asian continental margin is the source of the Kurosegawa Terrane has puzzled Japanese geologists for many years.
Firstly, we try to approach this issue based on the analysis of fusulinacean assemblage in accreted terranes composed of subduction complex in the Pacific Rim.
Secondly, by applying the result of this analysis we try to locate the source of the continental fragments of the Kurosegawa Terrane.
Thirdly, we try to prove its validity with a new paleomagnetic study. 相似文献
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There are many experimental approaches,field investigations and numerical calculations for movements of woods in a clear water and debris flow.However,kinematic conditions for accumulated logs and the interactions between a main flow and logs have not been fully evaluated.Mitigations for woods need taking into account the characteristics of tree species such as conifer and broad-leaf trees and of shapes such as root swells and crown.In the present study,we focus on the differences in specific weight of conifer and broad-leaf trees with some moisture in a sediment-water mixture flow with narrow flow width,and consider that conifer and broad-leaf tree are floating and submerged solid phase,respectively.Flume tests are conducted in steady flow of clear and debris flow over a rigid bed in order to evaluate conifer and broad-leaf tree movement in clear water and debris flow.Experimental data indicates that dimensionless transverse diffusion coefficient can be 0.1 to 0.4 and 0.3 to 0.9 in flow direction.Those diffusive characteristics seem to be independent of Reynolds number and Froude number,but dependent of bed slope,i.e.,gravity,though detailed considerations are needed to discuss about flow characteristics such as spatial eddy structures,momentum transfer induced by interactions of logs and so on. 相似文献
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Evaluation of the structural damage of high‐rise reinforced concrete buildings using ambient vibrations recorded before and after damage 
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下载免费PDF全文 Hirotoshi Uebayashi Masayuki Nagano Takenori Hida Takehiko Tanuma Mitoshi Yasui Shigeki Sakai 《地震工程与结构动力学》2016,45(2):213-228
Evaluation of the degrees of structural damage suffered by high‐rise residential buildings after being subjected to strong ground motions is extremely important to the development of life continuity planning for building residents. However, these evaluations cannot be based on strong‐motion records alone, because earthquake observation equipment is not installed in most such buildings in Japan. In this study, we propose simple equations for estimating the stiffness degradation rate and the peak inter‐story drift ratio (PIDR) by using ambient vibration records instead of strong‐motion records when high‐rise RC buildings are subjected to a severe earthquake. More specifically, we propose one equation that relates the square root of the stiffness degradation rate, which is the ratio of natural frequencies at the maximum response to the preliminary tremor response (elastic state), in strong‐motion records with the ratio of natural frequencies identified from ambient vibrations before and after damage was suffered. We also propose an equation that relates the PIDR with the stiffness degradation rate on the basis of the stiffness‐degrading bilinear restoring force characteristic derived from the strong‐motion records of 13 high‐rise buildings for the 1995 Hyogoken‐Nanbu Earthquake (Mw 6.9) and the 2011 Tohoku‐Oki Earthquake (Mw 9.0). Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
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Makoto Naoi Masao Nakatani Shigeki Horiuchi Yasuo Yabe Joachim Philipp Thabang Kgarume Gilbert Morema Sifiso Khambule Thabang Masakale Luiz Ribeiro Koji Miyakawa Atsushi Watanabe Kenshiro Otsuki Hirokazu Moriya Osamu Murakami Hironori Kawakata Nana Yoshimitsu Anthony Ward Ray Durrheim Hiroshi Ogasawara 《Pure and Applied Geophysics》2014,171(10):2665-2684
We investigated frequency-magnitude distribution (FMD) of acoustic emissions (AE) occurring near an active mining front in a South African gold mine, using a catalog developed from an AE network, which is capable of detecting AEs down to M W ?5. When records of blasts were removed, FMDs of AEs obeyed a Gutenberg?Richter law with similar b values, not depending on post-blasting time from the initial 1-min interval through more than 30 h. This result denies a suggestion in a previous study (Richardson and Jordan Bull Seismol Soc Am, 92:1766–1782, 2002) that new fractures generated by blasting disturb the size distribution of background events, which they interpreted as slip events on existing weak planes. Our AE catalog showed that the GR law with b ～ 1.2 was valid between M W ?3.7 and 0 for AEs around the mining front. Further, using the mine’s seismic catalog, which covers a longer time period of the same area, we could extend the validity range of the GR law with the same b value up to M W 1. 相似文献
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Jun Fan Tian-Chang Chen Wei-Bin Han Jian Zeng Si-Hua Zheng Akira Hasegawa Shigeki Horiuchi 《地震学报(英文版)》1998,11(3):375-379
Conclusions The real-time processing system of CTSN performs following: A/D conversion; automatic event detection; event data saving;
automatic measure of P and S arrivals; event location and print out the calculated results. It is corrected at ny moment by
using the off-line system. Since December 1993, this system has been operating normally in the CTSN. More than 4 000 earthquakes
have been recorded in the system. It has high accuracy in automatic picking P and S arrivals. The location of the earthquakes
determined by on-line system are close to those given in published catalogues which are determined by manual procedure. This
system can finish locate event in three minutes. It also gives satisfactory epicenter locations for distant events by inputting
manually S arrivals in the off-line system. The operation of this system had brought the technical superiority of the CTSN.
It not only reduces the labor intensity and simplifies the working procedure, but also makes our research facility into the
superior ranks in this field of our country.
In conclusion, the real-time processing system of seismic wave provides technical support for the daily requirements of monitoring
seismic activity as well as a lot of digital waveform data used seismic research in Sichuan area.
This subject is sponsored by the Scientific and Technical Committee of Sichuan Province. 相似文献
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For seismic hazard assessment, we study the variabilities of predicted ground motion on the basis of a ??recipe for predicting strong ground motion?? and propose approximations to evaluate spatial distributions of the standard deviation for PGV, R1.0, R2.0, and R5.0 in the estimated ground motions. For strong-motion prediction, we use a finite difference method for a long period range (>1.0?s). To estimate variabilities, a Monte Carlo simulation is used and we adopt the Latin Hypercube Sampling (LHS) technique to reduce computations. In this article, we consider only aleatory variabilities in source parameters among all possible variabilities, such as those in the source parameters, the propagation characteristics and site characteristics. Model sources are assumed for dip-slip fault and strike-slip fault, and the variabilities are considered for parameters such as asperity location, rupture starting point, average asperity slip contrast, stress drop and rupture velocity. On the target site, 100 instances of PGV, R1.0, R2.0 and R5.0 data are obtained for 100 sets of parameters and an average and a standard deviation of the log normal distribution, corresponding to the variability for ground motion estimation, are statistically analyzed. For all target sites uniformly distributed in the area around the faults, the average and the standard deviation are statistically analyzed and spread to spatial maps. It is found that the spatial distributions of standard deviation values for both the dip-slip and strike-slip faults are not uniform. Approximations are attempted to develop a quantitative evaluation for spatial distributions of the standard deviation of the log normal distribution for PGV, R1.0, R2.0, and R5.0. The spatial distributions by these approximations are considered to almost reconstruct the characteristics, which are statistically analyzed by the finite difference method. 相似文献
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Shigeki Inoue 《Monthly notices of the Royal Astronomical Society》2009,397(2):709-716
The dynamical friction problem is a long-standing dilemma about globular clusters (hereafter GCs) belonging to dwarf galaxies. GCs are strongly affected by dynamical friction in dwarf galaxies, and are presumed to fall into the galactic centre. But, GCs do exist in dwarf galaxies generally. A solution of the problem has been proposed. If dwarf galaxies have a core dark matter halo which has constant density distribution in its centre, the effect of dynamical friction will be weakened considerably, and GCs should be able to survive beyond the age of the Universe. Then, the solution argued that, in a cored dark halo, interaction between the halo and the GC constructs a new equilibrium state, in which a part of the halo rotates along with the GC (corotating state). The equilibrium state can suppress the dynamical friction in the core region. In this study, I tested whether the solution is reasonable and reconsidered why a constant density, core halo suppresses dynamical friction, by means of N -body simulations. As a result, I conclude that the true mechanism of suppressed dynamical friction is not the corotating state, although a core halo can actually suppress dynamical friction on GCs significantly. 相似文献
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