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71.
Overall SEDs based on ISO SWS observations show fair agreement with photospheric model predictions for red (super)giant stars.
However, some details of molecular spectra cannot be explained by a photospheric origin. In particular, fine structure in
the H2O 2.7 μm band can be clearly resolved by the SWS and is identified in an early M giant, whose photosphere will never
produce H2O. This is definite evidence for H2O of non-photospheric origin in an early M giant. Also, the observed H2O and
CO2 bands in a late M giant are too strong to be explained by a photospheric origin alone. Further, the H2O 2.7 μm band is
found in four early M supergiants in the h + χ Persei clusters (three of which show UIRs) and is especially strong in the
M4 supergiant S Per (which also shows a highly peculiar SED). Thus, against a belief that H2O is found only in the latest
M giants such as Miras, the SWS has revealed the presence of H2O in a wider region of the HR diagram. The origin of this H2O
is unknown but is probably in a non-photospheric extra envelope. Such a H2O envelope appears to be a general feature through
early M (super)giants to cool supergiants such as S Per, where the envelope has finally developed to be optically thick.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
72.
Shogo Aoki Kazumasa Aoki Mayuko Fukuyama Masatsugu Ogasawara Yuta Tsuchiya 《Island Arc》2021,30(1):e12420
In this study, the LA-ICP-MS zircon U–Pb dating of the Shimo-ondori diorites in the Shimanto accretionary complex of SW Japan provides ~130 Ma, representing the timing of their crystallization ages. Combined with the geological occurrence, that age clearly indicates that the diorites occur as blocks, not as intrusive rocks as suggested by previous studies. Moreover, the ages of the Shimo-ondori diorites are suggesstive that they could be influential for the estimate of the early-Cretaceous tectonic evolution for the eastern Asian margin. Their whole-rock chemical compositions show high MgO, Ni and Cr contents, and low total FeO/MgO ratios, indicating that they were crystallized from high magnesian andesite (HMA) magmas. Moreover, their TiO2 and REE compositions suggest that they were formed by the same processes as the sanukites. And, the zircon Hf isotopic ratios (εHf [~130 Ma] = +9.9 − +17.5), which is close to or slightly lower than that of the ~130 Ma depleted mantle, suggest that the wedge-mantle materials were predominantly involved in the formation of the dioritic magmas. Their geochronological and geochemical similarities of the Shimo-ondori diorites with the early Cretaceous adakites and HMAs in the eastern Asian margin suggest that they might have been formed possibly by the same slab rollback of the Izanagi plate at the early Cretaceous. After the crystallization of the Shimo-ondori diorites, they were delivered and deposited as blocks in a trench site with the surrounding sedimentary rocks of the Shimanto accretionary complex. 相似文献
73.
Kaori Aoki 《第四纪科学杂志》2020,35(1-2):93-101
A tephra layer with normal grading in the sub-bottom depth interval 119–122 cm in marine core SO202-27-6 was collected on Patton Seamount in the northeast North Pacific Ocean. Based on the geochemistry of volcanic glass shards determined by a wavelength dispersive electron probe micro-analyser and an X-ray fluorescence analyser, this layer is correlated to the Dawson tephra, a widespread late Pleistocene time marker tephra in Alaska and the Yukon. The age of the Dawson tephra in the core is 29.03 ± 0.178 ka (1 sigma) based on a published age model. The Dawson tephra is revealed to have been deposited in the transition from marine isotope stage 3 to 2, i.e. the last stage of Heinrich Stadial 3 derived from the ice-rafted debris signal. According to the correlation between Greenland (NGRIP ice core) and this core, the Dawson tephra occupies the record immediately before inter stadial 4 in the δ18O stratigraphy of NGRIP. The Dawson tephra on Patton Seamount includes lithic fragments, which suggests that it was deposited not only by fall-out but also in part via another mechanism, such as icebergs from the Cordilleran ice sheet or seasonal sea ice. 相似文献
74.
Daiki Yamamoto Shogo Tachibana Noriyuki Kawasaki Hisayoshi Yurimoto 《Meteoritics & planetary science》2020,55(6):1281-1292
Oxygen isotope exchange experiments between tens of nanometer‐sized amorphous enstatite grains and water vapor were carried out under a condition of protoplanetary disk‐like low water vapor pressure in order to investigate the survivability of distinct oxygen isotope signatures of presolar silicate grains in the protosolar disk. Oxygen isotope exchange between amorphous enstatite and water vapor proceeded at 923–1003 K and 0.3 Pa of water vapor through diffusive isotope exchange in the amorphous structure. The rate of diffusive isotope exchange is given by D (m2 s–1) = (5.0 ± 0.2) × 10–21 exp[–161.3 ± 1.7 (kJ mol–1) R–1 (1/T–1/1200)]. The activation energy for the diffusive isotope exchange for amorphous enstatite is the same as that for amorphous forsterite within the analytical uncertainties, but the isotope exchange rate is ~30 times slower in amorphous enstatite because of the difference in frequency factor of the reaction. The reaction kinetics indicates that 0.1–1 μm‐sized presolar amorphous silicate dust with enstatite and forsterite compositions would avoid oxygen isotope exchange with protosolar disk water vapor only if they were kept at temperatures below ~500–650 K within the lifetime of the disk gas. 相似文献
75.
Yuto Kurumada Shogo Aoki Kazumasa Aoki Daichi Kato Mototaka Saneyoshi Khishigjav Tsogtbaatar Brian F. Windley Shinobu Ishigaki 《地学学报》2020,32(4):246-252
To verify the usefulness of calcite U–Pb measurement for vertebrate‐bearing strata in the Eastern Gobi, Mongolia, we performed laser ablation‐inductively coupled plasma‐mass spectrometry calcite U–Pb and trace element analyses of three caliche (calcrete) of the Bayn Shire Formation. The trace element analysis demonstrates high concentration of U in the calcites. Two meaningful calcite U–Pb ages were obtained; 95.9 ± 6.0 and 89.6 ± 4.0 Ma, which are consistent with published ages from the Bayn Shire Formation. Our results demonstrate that the calcite U–Pb method can be powerful tool for age determination of vertebrate‐bearing strata in the Gobi that do not contain index fossils or beds, but do contain caliches. This would make it possible for a comparison of biostratigraphy between the Gobi and other areas yielding abundant vertebrate fossils in Asia, North America and Europe, based on chronological data. 相似文献
76.
Mohammad Hossein Erami Masakatsu Miyajima Shogo Kaneko Toshio Toshima Shozo Kishi 《地震工程与结构动力学》2015,44(3):403-417
This paper describes an investigation of pipe–soil interaction equations suggested by currently used pipeline seismic design codes and the applicability of these equations to segmented pipelines. The results of computer‐aided analyses were compared to results obtained in full‐scale experiments on a segmented ductile iron pipeline 93 mm in diameter and 15 m in length. The pipeline was installed 600 mm below the ground surface in a sandy soil compacted to two different subgrade reaction values. The type of fault considered was a reverse fault with an intersection angle of 60° with the pipeline, and the fault movement was a total of 350 mm in three same steps in the fault trace direction. The findings of this study demonstrate the necessity of considering the nature of soil behavior in pipe–soil interaction equations and the effects of connection joints on the integrated response of pipelines to fault‐induced ground deformations. A new combination of equations constituting a direction‐wise selection from among the equations proposed by currently used guidelines is introduced as a new series to describe pipe–soil interaction for segmented pipelines and is verified using the results of full‐scale experiments. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
77.
Kiyoshi Tanaka Kousei Komatsu Sachihiko Itoh Daigo Yanagimoto Miho Ishizu Hiroyasu Hasumi Takashi T. Sakamoto Shogo Urakawa Yutaka Michida 《Journal of Oceanography》2017,73(1):25-38
Hydrographic observations were made in Otsuchi Bay on the Sanriku ria coast, Japan, to provide clear images of the baroclinic circulation extending over the bay together with the associated intrusion of lower-layer water (bottom water) from outside the bay. In summer, a prominent baroclinic circulation with flow speeds \({>} 0.1\ \text{ m }\ \text{ s }^{-1} \) extends over the greater part of the bay. A main pycnocline (thermocline), which separates the upper and lower layers, is located at a depth of 15–40 m in and around the bay. The direction of the lower-layer flow (inflow into and outflow from the bay) is opposite to that of the upper-layer flow, which are baroclinically coupled to each other. Moreover, with regard to the lower-layer flow, the inflow tends to occur mainly through the northwestern part of the bay mouth, whereas the outflow tends to occur mainly through the southeastern part. The inflow and outflow alternate on time scales of several to a few tens of hours, and the flow directions are sometimes related to the tidal ones, although the relationship is not applied persistently. In winter, the baroclinic circulation is considerably weaker than in summer, because the stratification breaks down. 相似文献
78.
亚太地区环境综合监测的研究方法--APEIS项目研究综述 总被引:3,自引:0,他引:3
为了对亚太地区的环境灾害、环境破坏和环境退化及其影响进行监测和评估,由日本环境省发起的亚太地区环境革新战略项日(APEIS)环境综合监测子项(IEM)自2001年开始,建立了一个以MODIS卫星数据和地面观测资料为基础的综合环境监视网络系统。该网络系统起初是由日本国立环境研究所(NIES)和中国科学院地理科学与资源研究所(IGSNRR)共同合作建成的。之后,新加坡国立大学和澳大利亚联邦科学产业研究组织(CSIRO)地球观测中心也正式宣布加入,该系统覆盖整个亚太地区。美国宇航局(NASA)提供了一套MCDIS的高级数据产品,然而,这些产品没能在亚洲地区利用当地的实测资料进行充分地比较和验证。APEIS项目旨在提供利用该地区精确地面观测数据进行了比较验证的高质量数据集。利用该数据集可以推导出水分亏缺指数、沙尘暴指数、地表面温度、土地覆盖变化,以及净第一性生产量等一系列生态环境指标,从而埘环境破坏、环境退化和生态脆弱区进行长期有效的监测。为了评价水资源、食物生产等生态系所提供的产品与服务的现状和变化特征,本研究还开发了一个可利用M0DIS数据的流域环境综合管理模型。该模型已经被用于对流域规模的水、热、碳循环、泥沙转移以及农业生产等生态要素的模拟和评估,并利用高精度的观测资料对其进行了验证。利用该模式可以对流域生态系统所提供的产品与服务的有效利用,以及流域的可持续发展提供一系列战略性的政策选项。 相似文献
79.
Kojitani H. Nishimura K. Kubo A. Sakashita M. Aoki K. Akaogi M. 《Physics and Chemistry of Minerals》2003,30(7):409-415
Raman spectroscopy of calcium ferrite type MgAl2O4 and CaAl2O4 and heat capacity measurement of CaAl2O4 calcium ferrite were performed. The heat-capacity of CaAl2O4 calcium ferrite measured by a differential scanning calorimeter (DSC) was represented as CP(T)=190.6–1.116 × 107T–2 + 1.491 × 109T–3 above 250 K (T in K). The obtained Raman spectra were applied to lattice dynamics calculation of heat capacity using the Kieffer model. The calculated heat capacity for CaAl2O4 calcium ferrite showed good agreement with that by the DSC measurement. A Kieffer model calculation for MgAl2O4 calcium ferrite similar to that for CaAl2O4 calcium ferrite was made to estimate the heat capacity of the former. The heat capacity of MgAl2O4 calcium ferrite was represented as CP(T)=223.4–1352T –0.5 – 4.181 × 106T –2 + 4.300 × 108T –3 above 250 K. The calculation also gave approximated vibrational entropies at 298 K of calcium ferrite type MgAl2O4 and CaAl2O4 as 97.6 and 114.9 J mol–1 K–1, respectively. 相似文献
80.
A garnet lherzolite xenolith hosted in olivine nephelinite from Xilong,Zhejiang Province ,southeastern China, shows clear evidence of modal metasomatism involving a special sanidine-olivine-diopside(SOD) association which was produced by replacement of primary orthopyroxene.The fluid responsible for the measomatism was a silica-undersaturated vapour,rich in K,Ba,Sr and Ti.It is suggested that the SOD assemblage is the product of metasomatism of a depleted lherzolite precursor,and formed in the upper mantle prior to entrainment and eruption. 相似文献