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61.
This study has reviewed recent studies about impact of the Rossby wave propagation on the weather of East Asia.Then,we have focused on the northward progression of the subtropical high affected by the propagations and their interaction.The following results are obtained:(1) The two kinds of meridional Rossby wave propagations often affect the East Asian weather in summer,which propagate in two conflicting directions(northwest-southeastward and southwest-northeast-ward).This is considered as the interaction of the large-scale systems between high and low latitudes with wave propagation,especially to the circulation systems around East Asia.(2) The northward progression of the subtropical high is largely restrained,aecompanied by the southward shift of the convective activity in middle latitudes,under the strong and persistent Rossby wave propagation from high to low latitudes.And the opposite role could be found in the Rossby wave propagation from low to high latitudes. 相似文献
62.
This paper proposes a new analytical model for masonry‐infilled R/C frames to evaluate the seismic performance considering R/C frame–infill interactions. The proposed analytical model replaces masonry infill with a diagonal compression strut, which represents distributed compression transferred between frame and infill interfaces. The equivalent strut width is presented as a function of the frame–infill contact length, which can be evaluated by static equilibriums related to compression balance and lateral displacement compatibility at the frame–infill interfaces. The proposed analytical model was verified through comparisons with experimental results obtained for several brick masonry‐infilled R/C frames representing a typical R/C building with nonstructural masonry infill in Indonesia. As a result, good agreements were observed between the experimental and analytical values of the lateral strength and ductility of the infilled frames. The seismic performances of two earthquake‐damaged R/C buildings with different damage conditions were evaluated considering infill effects by applying the proposed analytical model. Consequently, the nonstructural brick masonry infill significantly affected the seismic resistances of the buildings, which seemed to lead to differing levels of damage for each building. These results indicate that the proposed analytical model can be an effective tool for more precisely screening earthquake‐vulnerable existing R/C buildings in Indonesia. Copyright © 2016 The Authors. Earthquake Engineering & Structural Dynamics Published by John Wiley & Sons Ltd. 相似文献
63.
Suspended particles collected from surface seawater during the SEEDS II (Subarctic Iron Experiment for Ecosystem and Dynamics Study II) experiment were analyzed individually using an electron probe X-ray micro analyzer and characterized by size and elemental composition. Their numbers, relative abundances, and relative particle volume all showed clear differences between samples collected inside vs. outside the phytoplankton bloom that developed following the addition of iron. Throughout the study, Si-rich, Ca-rich and Organic particles were dominant and their number increased inside the fertilized patch; these particles accounted for 21%, 13% and 58% of the particles examined, respectively. Si-rich or Ca-rich particles commonly consisted of fragments of diatom frustules and coccolithophorids. There was consistently greater percentage of Ca-rich particles and lower percentage of Si-rich particles inside the patch than outside of it in number, but both types of these particles apparently occupied a larger volume inside the patch than outside of it. Organic particles, that showed having peaks in smaller diameter particles, increased apparently inside the patch with time after iron fertilization. The Organic particles had a more diverse mixture of both bio-related and crustal trace elements than the other types of particles. These results suggest that the increase in suspended particles following the iron enrichment was due to a combination of detrital material and live phytoplankton. 相似文献
64.
Anil Kumar Vijayan Takashi Yoshikawa Shigeki Watanabe Hiroaki Sasaki Kazuhiko Matsumoto Sei-Ichi Saito Shigenobu Takeda Ken Furuya 《Journal of Oceanography》2009,65(2):245-258
Regional variations in the contribution of non-photosynthetic pigments (ā
np*) to the total light absorption of phytoplankton (ā
ph*) and its influence on the maximum quantum yield of photosynthesis (φ
m) were investigated. In the western equatorial Pacific, the surface ā
np* : ā
ph* ratio was higher in the western warm pool than that in the upwelling region. This difference appears to be attributable to
severe nitrate depletion and higher percentage of prokaryotes, which can accumulate very high concentrations of zeaxanthin
in the western warm pool. In the subarctic North Pacific, the ā
np* : ā
ph* ratio was expected to be higher in the Alaskan Gyre where the thermocline is sharper and iron limitation may possibly be
more severe than in the Western Subarctic Gyre. However, the ratio was actually higher in the Western Subarctic Gyre, contradictory
to our expectations. This east-west variation appears to be attributable to changes in the taxonomic composition; cyanobacteria
were more abundant in the Western Subarctic Gyre. The values of ā
np* : ā
ph* and its vertical variations were relatively small in the subarctic North Pacific compared to those in the western equatorial
Pacific. These inter-regional variations appear to be attributable to the lower solar radiation intensity, smaller percentage
of cyanobacteria, and relatively strong vertical mixing in the subarctic North Pacific. The spatial variations in ā
np* : ā
ph* significantly influence φ
m. In comparison with φ
m based on the total light absorption (φ
m ph), the values corrected for the contribution of non-photosynthetic pigments (φ
m ps) showed an increase in both the western equatorial Pacific and the subarctic North Pacific. 相似文献
65.
Y. Shirasaki F. Kakimoto S. Ogio N. Gironda M. Takeda T. Kaneko H. Yoshii T. Baba S. Sano K. Nishi N. Tajima Y. Yamada S. Shimoda H. Nakatani E. Gotoh K. Murakami Y. Toyoda Y. Matsubara Y. Mizumoto W. Velasquez A. Velarde P. Miranda 《Astroparticle Physics》2001,15(4):118-381
The chemical composition of primary cosmic rays with energies from 1015 to 1016.5 eV, so called “knee” region, is examined. We have observed the time structures of air Čerenkov light associated with air showers at Mt. Chacaltaya, Bolivia, since 1995. The distribution of a parameter that characterizes the observed time structures is compared with that calculated with a Monte Carlo technique for various chemical compositions. Then the energy dependence of the average logarithmic mass numbers ln A of the primary cosmic rays is determined. The present result at 1015.3 eV is almost consistent with the result of JACEE (A12) and shows gradual increase in ln A as a function of the primary energy (A24 at 1016 eV). Form the comparison of the observational results with several theoretical models, we conclude that the supernova explosion of massive stars is a plausible candidate for the origin of cosmic rays around the “knee” region. 相似文献
66.
江西永平铜矿花岗质岩石的岩石结构、地球化学特征及其成矿意义 总被引:2,自引:7,他引:2
江西永平铜矿位于华南怀玉山—北武夷山铜铅锌多金属成矿带内,是赣东北地区除了德兴铜矿外的另一个大型铜矿基地。该矿区存在两种类型的花岗质岩石,一种是花岗岩;另一种是英安斑岩。英安斑岩具有典型斑状结构和石英眼结构,而花岗岩则具有单向固结结构。在化学成分上,两者属于高钾的钙碱性系列岩石,英安斑岩贫硅、富Al、Fe、Mg、Ca,以及具有较大的Na_2O/K_2O(0.02~0.64)等特点;而花岗岩富硅、贫Al、Ca,以及富碱和具有较小的Na_2O/K_2O(0.02~0.03)等特点。两种类型的岩石具有一致的REE配分曲线。它们均富集大离子亲石元素(Ba、Rb、K),亏损高场强元素(Th、Nd、Ta、Ti)以及元素Sr和P,显示了与俯冲作用有关的岩浆作用。在结构和化学成分上,花岗岩则类似于美国Climax斑岩钼(铜)矿成矿斑岩的性质(如具有单向固结结构、较高的分异指数、富Si、贫Al、Ca、富Na_2O K_2O以及K_2O>Na_2O)。与英安斑岩有关的蚀变作用主要有夕卡岩化、黑云母化、白云母化、绿泥石化和萤石化,而与花岗岩有关的蚀变作用主要是白云母化和萤石化;相应地,与英安斑岩有关的成矿作用主要为铜,而与花岗岩有关的成矿作用则主要为钼。2件辉钼矿样品的Re-Os年龄分别为156.7±2.8Ma和155.7±3.6Ma,表明与花岗岩有关的钼成矿作用发生在156Ma左右。本文认为,永平铜钼矿的成矿地球动力学背景应是由挤压向伸展的转换环境。 相似文献
67.
Ken Yanagisawa Fumihiko Imamura Tsutomu Sakakiyama Tadashi Annaka Tomoyoshi Takeda Nobuo Shuto 《Pure and Applied Geophysics》2007,164(2-3):565-576
The present study focuses on evaluation of the maximum and minimum water levels caused by tsunamis as risk factors for operation
and management at nuclear power facilities along the coastal area of Japan. Tsunamis generated by submarine earthquakes are
examined, basing literature reviews and databases of information on historical tsunami events and run-up heights. For simulation
of water level along the coast, a numerical calculation system should be designed with computational regions covering a particular
site. Also the calculation system should be verified by comparison of historical and calculated tsunami heights. At the beginning
of the tsunami assessment, the standard faults, their locations, mechanisms and maximum magnitudes should be carefully estimated
by considering historical earthquake-induced tsunamis and seismo-tectonics at each area. Secondly, the range of errors in
the model parameters should be considered since earthquakes and tsunamis are natural phenomena that involve natural variability
as well as errors in estimating parameters. For these reasons, uncertainty-induced errors should be taken into account in
the process of tsunami assessment with parametric study of the tsunami source model. The element tsunamis calculated by the
standard fault models with the errors would be given for the design. Then, the design tsunami can be selected among the element
tsunamis with the most significant impact, maximum and minimum water levels, on the site, bearing in mind the possible errors
in the numerical calculation system. Finally, the design tsunami is verified by comparison with the run-up heights of historical
tsunamis, ensuring that the design tsunami is selected as the highest of all historical and possible future tsunamis at the
site. 相似文献
68.
Takeshi Ohba Yasushi Daita Takeshi Sawa Noriyasu Taira Yusuke Kakuage 《Bulletin of Volcanology》2011,73(4):457-469
The chemical and isotopic compositions of volcanic gases at a borehole and a natural fumarole in the Owakudani geothermal
area, Hakone volcano, Japan, have been repeatedly measured since 2001, when a seismic swarm occurred in the area. The CO2/H2O and CO2/H2S ratios were high in 2001. It increased in 2006 and again in 2008 when seismic swarms occurred beneath the geothermal area.
The observed increases suggest the injection of CO2- and SO2-rich magmatic gas into the underlying hydrothermal reservoir, implying that the magmatic gas was episodically supplied to
the hydrothermal system in 2006 and 2008. The earthquake swarms probably resulted from the injection of gas through the shallow
crust accompanying the break of the sealing zone. 相似文献
69.
70.
Masayuki Uesugi Ryo Noguchi Tooru Matsumoto Junya Matsuno Takashi Nagano Akira Tsuchiyama Shigenori Harada Kaori Yokoyama Yoshiaki Yodo Noboru Takeda Toru Yada Shogo Yakame Yuzuru Karouji Yukihiro Ishibashi Masanao Abe Tatsuaki Okada Akio Fujimura Mitsuru Ebihara Fumio Kitajima Keisuke Nagao Tomoki Nakamura Hiroshi Naraoka Takaaki Noguchi Ryuji Okazaki Hisayoshi Yurimoto 《Meteoritics & planetary science》2014,49(7):1186-1201
We report the investigation of cutting methods for Hayabusa samples. The purpose of our study is to explore the possibility of applying multiple analyses to a single particle effectively. We investigated the cutting performance of a blade dicing saw, laser, focused ion beam (FIB), and physical breaking by microindenter. Cutting performance was examined by estimating the aspect ratio of the cut slit, i.e., depth over width of the slit. We also investigated the possible contamination and sample damage by cutting. The result of the investigation shows that we can cut the samples from <50 μm to 500 μm using those methods with aspect ratios from 10 to 20, although they would introduce some contamination or damage to the samples. Our investigations also provide an important basis for the analysis of samples obtained by future sample return missions. 相似文献