The hydroxyl column abundance in the middle atmosphere is measured with ground-based uv spectroscopy using the sun as a light source. The present method is distinctive in that it utilizes the Doppler shift of the solar spectrum due to the solar rotation to discriminate the slight terrestrial hydroxyl absorption from prominent solar features. By comparing the spectra measured on the east and the west edges of the solar disk, it is possible to cancel out most of the solar structures and to make the terrestrial features much more evident. 相似文献
To examine the fatigue process of granite, cylindrical Westerly granite specimens, 10 mm in diameter and 20 mm in length, were subjected to a cyclic loading test under uniaxial compression with a maximum of 140 MPa at room temperature, and crack growth patterns within them were analyzed by microscopic observation and image analysis techniques. The fatigue process is divided into three characteristic stages; a primary stage in which the upper peak strain increases at a decelerating rate (stage I), a second stage with linearly slight increasing rate of strain following stage I (stage II), and the third and final stage in which the upper peak strain increases at an accelerating rate and culminates in specimen failure (stage III). A series of prefailure specimens, of which the stage in the fatigue process was decided by monitoring the strain behavior during the test, were retrieved. In addition, these specimens were compared with specimens stressed to close to the breaking strength by monotonic compression to examine the characteristic features of fatigue. The fluorescent method was applied to identify microcracks within the specimens. The advantage of this method is to provide quick and accurate identification of microcracks with an optical microscope. Microcracks are detected based on a marked difference in brightness under ultraviolet light irradiation because they are fully filled with acrylic resin mixed with a fluorescent substance in advance. Thin sections, including the axis of the specimen, 10 × 20 mm, were prepared for detailed observation after the pretreatment of the method.The results were as follows. At the initial degradation stage, distinguishing crack growth was identified in quartz grains. It is estimated that the slowdown of the strain growth rate at this stage was caused by the decrease in crack growth, that is, the portions with cracking potentiality were damaged at the first or early loading, and no further damage occurred immediately following the first damage. At the second stage, no significant crack growth in quartz grains was identified. On the other hand, in feldspar grains, development of cracks in a preferential direction, parallel to the loading direction, was observed. However, they did not grow into intergranular cracks by cutting across the grain boundaries during this stage. Consequently, it was found that a gradual progress of microcracks within feldspar grains was dominant during the second stage, and this is because the strain growth rate was in a steady and long state. At the final accelerated stage, many intergranular cracks running parallel to the loading direction were identified. It is obvious that these long cracks were formed mainly by the linking and growth of the intragranular cracks in feldspars, which were generated during the former stages. Their formation takes the fatigue process from the second stage to the final stage with a sharp increase in strain, and their further development seemed to lead the whole specimen to ultimate fatigue failure. 相似文献
The Gour Oumelalen area exposes Paleoproterozoic (1.9 Ga) marbles and calc-silicate granulites. Some marbles show a specific mineralogy characterized by the presence of a highly aluminous clinopyroxene with Al2O3 content exceeding16 wt%. This clinopyroxene shows a marked zoning with a hedenbergitic core rimmed by fassaite. Phase relations are expressed by spectacular reaction textures in calc-silicate granulites as Opx + Cpx + Pl + H2O == > Grt + Qtz ± Am and Cpx + Ilm + Pl ± Mt = > Grt + Qtz + Spn. In olivine-bearing marbles, clinopyroxene and dolomite occur around olivine and calcite. According to thermodynamic modeling in the Na2O–CaO–FeO–MgO–Al2O3–SiO2–H2O–TiO2–Fe2O3 (NCFMASHTO) system, the first stage of metamorphism is located at 800 °C and 6–7 kbar, which is followed by an increase in pressure at 9–10 kbar and 800 °C and an isobaric cooling at 680 °C. The deduced anticlockwise P–T path is consistent with a granulitic metamorphism occurring in an active continental margin context.
It was argued that 3C 66B, a nearby radio galaxy, harbors a supermassive black hole binary (SMBHB). To investigate this, a 4-epoch VLBA phase referencing imaging observation was performed in 2004–2005. Here we present some preliminary results of this project. We found a large position difference compared to previous results. 相似文献
Epsilon Aurigae has been observed during ingress and totality between 1982 and 1983 at Okayama. Analyses of profiles of H line and of radial velocities of neutral hydrogen and metals show that the secondary component consists of at least three parts in structure.Paper presented at the Lembang-Bamberg IAU Colloquium No. 80 on Double Stars: Physical Properties and Generic Relations, held at Bandung, Indonesia, 3–7 June, 1983. 相似文献
Data from the R/V Mirai cruise (May–June 2000) have been examined to discover how mesoscale processes associated with eddy dynamics direct affect
the water masses, the distributions and the vertical fluxes of the dissolved oxygen, nutrients and dissolved inorganic carbon
in the western subarctic Pacific. Using maps of the temperature, salinity, dissolved oxygen, nutrients, chlorophyll and sea-air
pCO2 difference we show that the boundaries of the anticyclone eddies in the study region were composed of high productivity coastal
Oyashio water. The coastal waters were wrapped around the anticyclone eddies (thus creating a high productivity belt) and
intruded inside of them. Using SeaWifs data we demonstrate that temporal variations in the position and the strength of anticyclone
eddies advected the Kuril island coastal high productivity waters to the pelagic part, resulting in temporal variations of
the chlorophyll in the Oyashio region. Computed vertical fluxes of the dissolved oxygen (DO), inorganic carbon (DIC) and silicate
show that the anticylonic eddies in the Kuroshio-Oyashio Zone are characterized by enhanced vertical fluxes of the DO and
DIC between the upper (σθ = 26.7–27.0) and lower (σθ = 27.1–27.5) intermediate layer, probably due to the intrusions of the Oyashio waters into the eddies.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
Seasonal and vertical changes in abundances of bacteria and heterotrophic nanoflagellates (HNF), and HNF grazing on bacteria were investigated in a small eutrophic inlet of Uranouchi-Wan throughout the years. Bacterial densities in the surface water ranged from 1.2 to 11 (average 4.3)×106 cells ml–1 with a couple of maxima following the algal blooming. Densities of HNF ranged from 0.54 to 73 (average 16.4)×103 cells ml–1 in the surface, and showed almost similar fluctuation pattern to that of bacteria with a time lag of about 1 to 2 weeks. Grazing rates of HNF on bacteria obtained by FLB method were 4.78 to 16.9 (average 10.3±SD 4.8) cells HNF–1h–1 in the surface layer in summer, and consequent total bacterial consumption rates by HNF fluctuated from 4 to 99×104 cells ml–1h–1. In deeper layers, however, as HNF densities and grazing rates on bacteria were low, the grazing pressure of HNF on bacteria was small. Turnover times of bacteria by HNF grazing in the surface layer were calculated as relatively constant values of 40 to 60 h, however, it decreased to as low as 6 to 7 h when the HNF activity was highest. These results indicate that bacteria grew so actively by consuming organic matter in seawater as to compensate high HNF grazing pressure, and that bacteria and HNF in the microbial loop play important roles on the turnover of substrates in coastal ecosystems. 相似文献
Geographical Survey Institute is going to produce Land condition maps of volcano about active volcanoes given the priority by the Geodesy Council. This paper introduces these land condition maps of volcano and other geomorphological maps for the research of volcanic disaster, especially the research of debris avalanche on Bandai Volcano. 相似文献
The 2005 northern Pakistan earthquake (magnitude 7.6) of 8 October 2005 occurred in the northwestern part of the Himalayas.
We interpreted landslides triggered by the earthquake using black-and-white 2.5-m-resolution System Pour l’Observation de la Terre 5 (SPOT 5) stereo images. As a result, the counts of 2,424 landslides were identified in the study area of 55 by 51 km. About
79% or 1,925 of the landslides were small (less than 0.5 ha in area), whereas 207 of the landslides (about 9%) were large
(1 ha and more in area). Judging from our field survey, most of the small landslides are shallow rock falls and slides. However,
the resolution and whitish image in the photos prevented interpreting the movement type and geomorphologic features of the
landslide sites in detail. It is known that this earthquake took place along preexisting active reverse faults. The landslide
distribution was mapped and superimposed on the crustal deformation detected by the environmental satellite/synthetic aperture
radar (SAR) data, active faults map, geological map, and shuttle radar topography mission data. The landslide distribution
showed the following characteristics: (1) Most of the landslides occurred on the hanging-wall side of the Balakot–Garhi fault;
(2) greater than one third of the landslides occurred within 1 km from the active fault; (3) the greatest number of landslides
(1,147 counts), landslide density (3.2 counts/km2), and landslide area ratio (2.3 ha/km2) was found within Miocene sandstone and siltstone, Precambrian schist and quartzite, and Eocene and Paleocene limestone and
shale, respectively; (4) there was a slight trend that large landslides occurred on vertically convex slopes rather than on
concave slopes; furthermore, large landslides occurred on steeper (30° and more) slopes than on gentler slopes; (5) many large
landslides occurred on slopes facing S and SW directions, which is consistent with SAR-detected horizontal dominant direction
of crustal deformation on the hanging wall. 相似文献