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排序方式: 共有357条查询结果,搜索用时 573 毫秒
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Irvine WM Friberg P Hjalmarson A Ishikawa S Kaifu N Kawaguchi K Madden SC Matthews HE Ohishi M Saito S Suzuki H Thaddeus P Turner BE Yamamoto S Ziurys LM 《The Astrophysical journal》1988,334(2):L107-L111
We report the astronomical identification of the cyanomethyl radical, CH2CN, the heaviest nonlinear molecular radical to be identified in interstellar clouds. The complex fine and hyperfine structures of the lowest rotational transitions at about 20.12 and 40.24 GHz are resolved in TMC-1, where the abundance appears to be about 5 x 10(-9) relative to that of H2. This is significantly greater than the observed abundance of CH3CN (methyl cyanide) in TMC-1. In Sgr B2 the hyperfine structure is blended in the higher frequency transitions at 40, 80, and 100 GHz, although the spin-rotation doubling is clearly evident. Preliminary searches in other sources indicate that the distribution of CH2CN is similar to that for such carbon chain species as HC3N or C4H. 相似文献
4.
Mihoko Hoshino Mitsuyoshi Kimata Norimasa Nishida Masahiro Shimizu 《Physics and Chemistry of Minerals》2008,35(2):59-70
Dissakisites from Trimouns dolomite mine, France, have two kinds of single crystals: chemical-zoned and homogeneous types.
Back-scattered electron microprobe (BSE) images of these dissakisites reveal both Ca–Al rich dark zones and Fe-ΣREE rich bright
zones. Crystal structures of three dark and two bright zones in a chemical-zoned dissakisite and of a homogeneous zone in
unzoned dissakisite were refined to individual R indices (about 3.0–5.0%) based on 1,400 observed [|F
0| > 4σF
0] reflections measured with MoKα X-radiation using the single crystal diffractometer. The differences in brightness between
their BSE images arise from those in coupled substitutions of the elements occupying A2 and M3 sites. The main reason for
these differences is that ten-coordinated A2 polyhedra and M3 octahedra are directly linked through their shared edge, which
creates a great potential for making this coupled substitution. This zoning indicates that formation of the whole zoned crystal,
where each zone could be grown steadily with its crystallographic axes mutually parallel to each other, may be identified
as autoepitaxy. 相似文献
5.
The study of the Kuroshio in the East China Sea and the currents east of the Ryukyu Islands 总被引:3,自引:0,他引:3
In this study, the inverse method is used to compute the Kuroshio in the East China Sea and southeast of Kyushu and the currents east of the Ryukyu Islands, on the basis of hydrographic data obtained during September-October, 1987 by R/V Chofu Maru. The results show that: (1)A part of the Taiwan Warm Current has a tendency to converge to the shelf break; (2) the Kuroshio flows across the section C3 (PN) with a reduced current width, and the velocity of the Kuroshio at the section C3 increases and its maximum current speed is about 158 cm/s, and its volume transport here is about 26×106m3/s; (3) the Kuroshio has two current cores at the sections C3 (PN) and B2 (at the Tokara Strait); (4) the currents east of the Ryukyu Islands are found to flow northward over the Ryukyu Trench during September-October, 1987. The velocities of the currents are not strong throughout the depths. At the section C2 east of the Ryukyu Islands, the maximum current speed is at the 699 m levei and its magnitude is 25 cm/s, and i 相似文献
6.
Ichiro Ishikawa Shigeaki Aoki Ryo Furue Nobuo Suginohara 《Journal of Oceanography》1996,52(5):617-632
In recognition that similarity in the density balance leads to resemblance in circulation between the two-dimensional non-rotating and three-dimensional rotating systems which have similar density stratification, we investigate convection induced by cooling at one side wall and heating at the sea surface by using a two-dimensional non-rotating model as idealized representation for the deep Pacific circulation. In the model, various vertical profiles are taken for the side wall cooling, which are assumed to correspond to the density structure of the Anatarctic Circumpolar Current. In a small diffusivity range, two important features are found to be robust against change in the vertical profile of the side wall cooling. One is that the density stratification is horizontally almost uniform. The other is that the balance in the density equation between the vertical advection and the vertical diffusion holds in the interior. Consequently, the vertical density balance, together with the equation of continuity, determines the circulation pattern for the prescribed vertical profile of the side wall cooling. The multi-layered meridional flow, which is expected to exist in the deep Pacific, is shown to form for certain vertical profiles of the side wall cooling. 相似文献
7.
Tetsuo Yanagi Koji Ishikawa Koh-ichi Inoue Satoshi Susami 《Journal of Oceanography》1995,51(2):225-238
The detailed flow structure around a tical front in Hiuchi-Nada, Japan was observed with the use of ADCP (Acoustic Doppler Current Profiler). The surface convergence region is observed at the transition zone between vertically well mixed area and the stratified area. The surface divergence regions exist next to the surface convergence region. The strong downward current is estimated in the middle layer just below the surface convergence region. The maximum surface convergence and the maximum downward velocity in the middle layer are 1.0×10–4 s–1 and 0.12 cm s–1, respectively. 相似文献
8.
Masahiro Endoh 《Journal of Oceanography》1975,31(1):51-52
It is shown by a numerical experiment with fine grid that the finite difference form of rotation of the Coriolis force used in ENDOH (1973) gives practically the same solution as that obtained by the use of the finite difference form pointed out byTakano (1974). 相似文献
9.
10.
Masahiro Endoh 《Journal of Oceanography》1973,29(1):16-27
A numerical experiment is made using a barotropic model for the western boundary currents. The time-dependent, non-linear vorticity equation is integrated with and without the variable of bottom topography. The inertial and frictional boundary flow is resolved with a fine grid size of 10 km. Connection of the western boundary currents with the general circulation is facilitated by giving the fixed Sverdrup transport at the eastern boundary of the model (400 km offshore).For the flat bottom topography, steady flow forRe=35 shows dynamical balance essentially of a frictional model. The transient response leading to the formation of the western boundary currents in the model seems to support theLighthill's theory (1969). ForRe=350, unsteady features revealed byBryan (1963) is re-established. A phenomenon of barotropic instability is also observed with sufficient resolution. For the model with a continental slope the steady flow is also obtained forRe=35. The boundary currents flow over the continental slope, deviating offshore as they flow northward. 相似文献