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21.
Naoto Iwasaka Yuichi Isozaki Susumu Kuwashima Hirotaka Otobe Kimio Hanawa 《Journal of Oceanography》2000,56(6):717-726
In situ observation of downward solar radiation in the Western Pacific were carried out with voluntary merchant ships for five years from autumn 1990 through autumn 1995. Daily means of the short wave radiation were computed from the observed solar radiation. Then, the effects of shadows of the ship's superstructures on the observed radiation were corrected if needed. A 5-year average of short wave radiation along the main sea-lanes in the Western Pacific was calculated based on the observed daily mean solar radiation. Maximum values of 270–280 Wm–2 are found around 15°–20°N in May and June, while those of 290 Wm–2 are observed south of 18°S in November and December along the lanes. Small annual variations are found in the equatorial region. Annual mean values at the equator are about 230 Wm–2 between New Guinea and Indonesia, and 200 Wm–2 east of New Guinea. The 5-year average of short wave radiation was compared with the climatologies given in previous studies. We have concluded that some of results of previous studies are significantly underestimated. 相似文献
22.
Fine sludges were collected from five filtration plants, and the partitioning of ten metals (Ag, Cd, Mn, Zn, Pb, Cu, Sn, Co, Ni, and Fe) in them was determined by selective leaching techniques. (1) The available amounts, which shows the total of each metal leached between 1 M CH3COONH4 and 30 percent H2O2, for Ag, Cd and Mn, ranged from 51 to 98 percent for five sludges. (2) The available amounts for Zn, Pb, Cu, and Sn were 47–92 percent for five sludges. (3) The most important fraction for Co, Ni, and Fe, except the Inagawa sludge, which is markedly polluted by organic matter, was the crystalline particle. Therefore, the above metals, except Co, Ni, and Fe, are thought to be enriched on ion-exchangeable sites, organic matter, hydrous Fe/Mn oxides, and sulfides in fine sludges. 相似文献
23.
Nobuki Kawashima Kazunori Akai Yukio Murasato Susumu Sasaki 《Astrophysics and Space Science》1984,106(1):117-123
In an electron beam emission experiment on board the EXOS-B (JIKIKEN) satellite (200 V, 1 mA-maximum), several types of waves are strongly excited by the beam such as plasma frequency, upper hybrid frequency, electron cyclotron frequency, their harmonics and nonlinear coupling of these waves. Measurements of these waves give information on local plasma density and magnetic field strength and it is revealed that the electron beam emission from the spacecraft is a powerful diagnostic tool in the magnetosphere. A long term observation in this electron beam experiment has provided us with the average plasma density profile in the magnetosphere. It is also useful for the detection of the plasmapause. Plasma density measurements down to the order of 10 cm–3 are possible. The instrument itself is very simple and compact, so that it will be a powerful plasma diagnostic tool in future magnetospheric and planetary explorations. 相似文献
24.
Saito Susumu Sunda Surendra Lee Jiyun Pullen Sam Supriadi Slamet Yoshihara Takayuki Terkildsen Michael Lecat Frédéric 《GPS Solutions》2017,21(4):1937-1947
GPS Solutions - We investigated characteristics of anomalous spatial gradients in ionospheric delay on GNSS signals in the Asia-Pacific (APAC) low-magnetic latitude region in the context of the... 相似文献
25.
The Sunda Strait is located in a transitional zone between two different modes of subduction, the Java frontal and Sumatra oblique subductions. Western Java and Sumatra are, however, geologically continuous.The Krakatau complex lies at the intersection of two graben zones and a north-south active, shallow seismic belt, which coincides with a fracture zone along this seismic belt with fissure extrusion of alkali basaltic rocks commencing at Sukadana and continuing southward as far as the Panaitan island through Rajabasa, Sebuku and Krakatau.Paleomagnetic studies suggest that the island of Sumatra has been rotating clockwise relative to Java from at least 2.0 Ma to the present at a rate of 5–10h/Ma, and therefore the opening of the Sunda Strait might have started before 2 Ma (Nishimura et al. 1986).From geomorphological and seismological studies, it is estimated that the western part of Sumatra has been moving northward along the Semangko fault and the southern part of Sunda Strait has been pulled apart.Assuming that the perpendicular component (58 mm/yr; Fitch 1972) of the oblique subduction has not changed, we can estimate that the subduction started at 7–10 Ma. Huchon and LePichon (1984) also estimated that the subduction started at 13 Ma.Recent crustal earthquakes in the Sunda Strait area are clustered into three groups: (1) beneath the Krakatau complex where they are typically of tectonic origin, (2) inside a graben in the western part of the strait, and (3) in a more diffuse zone south of Sumatra. The individual and composite focal mechanisms of the events inside the strait show an extensional regime. A stress tensor, deduced from the individual focal mechanisms of the Krakatau group shows that the tensional axis has a N 130°E orientation (Harjono et al. 1988).These studies confirm that the Sunda Strait is under a tensional tectonic regime as a result of clockwise rotation along the continental margin and northward movement of the Sumatra sliver plate along the Semangko fault zone. 相似文献
26.
Kenzo Toki Tadanobu Sato Junji Kiyono Nozar Kishi Garmroudi Susumu Emi Masaaki Yoshikawa 《地震工程与结构动力学》1991,20(10):895-909
Non-linear seismic soil-pile interaction was studied with a hybrid procedure that used a pseudo-dynamic testing (PDT) method modified to account for frequency dependence and developed for foundation-soil systems. The numerical scheme used in the conventional PDT was improved by the introduction of a time-dependent pseudo-forcing function derived from the frequency-dependent dynamic characteristics of the system by Hilbert transformation in the frequency domain. Single, 2-, 3- and 9-pile group foundation models were used, their mechanical characteristics later being determined from static and forced vibration dynamic tests. Amplitude scaling was used for three recorded accelerograms. Data recorded during an earthquake at the site of the experiments revealed that the proposed methodology predicts well seismic nonlinear interaction and accounts for frequency dependence and non-linearity in the time domain. 相似文献
27.
Kenzo Toki Tadanobu Sato Junji Kiyono Nozar Kishi Garmroudi Susumu Emi Masaaki Yoshikawa 《地震工程与结构动力学》1990,19(5):709-723
Non-linear seismic soil-structure interaction is studied through a hybrid procedure using the pseudo-dynamic testing (PDT) method which is modified to take into account frequency dependence and developed for foundation-soil systems. The numerical scheme used in conventional PDT is improved by introduction of a time-dependent pseudo-forcing function which is derived from frequency-dependent dynamic characteristics of the system by means of Hilbert transformation in the frequency domain. Surface, shallow and caisson foundation models that differed in size and depth of embedment were used. The mechanical characteristics of the systems were determined from static and forced vibration dynamic tests. An amplitude scaling technique was used for three recorded accelerograms. 相似文献
28.
Naoto Iwasaka Susumu Kuwashima Hirotaka Otobe Kimio Hanawa Hideki Hagiwara Ruri Suzuki 《Journal of Oceanography》1994,50(6):713-723
We have been performingin situ measurement of downward short wave radiation (solar radiation) in the western Pacific Ocean in cooperation with voluntary ships since autumn 1990 in order to obtain much more precise knowledge of downward short wave radiation at the sea's surface than before. Preliminary result of the observation from autumn 1990 through spring 1992 is shown in this paper. The comparison of observed daily mean downward short wave radiation with that estimated from observed cloudiness by using Reed (1977) formula is also presented to show the necessity ofin situ measurement in the study of the downward short wave radiation at the sea's surface. 相似文献
29.
30.
Rasoul B Sorkhabi Arvind K Jain Susumu Nishimura Tetsumaru Itaya Nand Lal R M Manickavasagam Takahiro Tagami 《Journal of Earth System Science》1994,103(1):83-97
Thermotectonic history of the Trans-Himalayan Ladakh Batholith in the Kargil area, N. W. India, is inferred from new age data
obtained here in conjunction with previously published ages. Fission-track (FT) ages on apatite fall around 20±2 Ma recording
cooling through temperatures of ∼100°C and indicating an unroofing of 4 km of the Ladakh Range since the Early Miocene. Coexisting
apatite and zircon FT ages from two samples in Kargil show the rocks to have cooled at an average rate of 5–6°C/Ma in the
past 40 Ma. Zircon FT ages together with mica K−Ar cooling ages from the Ladakh Batholith cluster around 40–50 Ma, probably
indicating an Eocene phase of uplift and erosion that affected the bulk of the batholith after the continental collision of
India with the Ladakh arc at 55 Ma. Components of the granitoids in Upper Eocene-Lower Oligocene sediments of the Indus Molasse
in Ladakh supports this idea. Three hornblende K−Ar ages of 90 Ma, 55 Ma, and 35 Ma are also reported; these distinctly different
ages probably reflect cooling through 500–550°C of three phases of I-type plutonism in Ladakh also evidenced by other available
radiometric data: 102 Ma (mid-Cretaceous), 60 Ma (Palaeocene), and 40 Ma (Late Eocene); the last phase being localised sheet
injections. The geodynamic implications of the age data for the India-Asia collision are discussed. 相似文献