49,999 research outputs found
Investigation of environmental change pattern in Japan. Classification of shorelines
There are no author-identified significant results in this report
Investigation of environmental change pattern in Japan. Utilization of LANDSAT-2 data for fisheries
The author has identified the following significant results. MSS data provided extensive and simultaneous information about marine environmental conditions, such as the shift of the Kuroshio, fall and rise of coastal water mass, distribution of water masses, locations of vortex and current rips, exchanges of water between embayment and open ocean effluent rivers, fertility of plankton, red tide, pollution, etc
Formation and structure of equatorial anticyclones caused by large scale cross equatorial flows determined by ATS-1 photographs
Atmospheric models for cross equatorial air mass flow and anticyclone formatio
The central simple modules of Artinian Gorenstein algebras
Let A be a standard graded Artinian algebra over a field of characteristic
zero and let z be a linear form in A. We define the central simple modules for
each such pair (A, z). Assume that A is Gorenstein. Then we prove that A has
the strong Lefschetz property if and only if there exists a linear form z in A
such that all central simple modules of the pair (A,z) have the strong
Lefschetz property. In the course of proof we need to extend the definition of
the strong Lefschetz property to finite graded modules over graded Artinian
algebra, which previously was defined only for standard graded Artinian
algebras.Comment: 20 pages, To be published in Journal of Pure and Applied Algebr
General pattern of the turbid water in the Seto-inland sea extracted from multispectral imageries by the LANDSAT-1 and 2
The author has identified the following significant results. Each distribution pattern of turbid water changes with the time in accordance with daily tides, seasonal variation of tides, and occasional rainfall. Two cases of successfully repeated LANDSAT observations for the same sea regions suggested a general pattern of turbid water could be extracted for each region. Photographic and digital processes were used to extract patterns of turbid water separately from the cloud and smog-layer in MSS 4, 5, and 7 imageries. A mosaic of image-masked imageries displays a general pattern of turbid water for almost the entire Seto Inland Sea. No such pattern was extracted for the Aki-Nada south of Hiroshima City where the water is fairly polluted, nor for the Iyo-Nada where the water is generally clearer than in other regions of the Seto Inland Sea
Fermi Surface Reconstruction without Breakdown of Kondo Screening at Quantum Critical Point
Motivated by recent Hall-effect experiment in YbRhSi, we study ground
state properties of a Kondo lattice model in a two-dimensional square lattice
using variational Monte Carlo method. We show that there are two types of phase
transition, antiferromagnetic transition and topological one (Fermi surface
reconstruction). In a wide region of parameters, these two transitions occur
simultaneously without the breakdown of Kondo screening, accompanied by a
discontinuous change of the Hall coefficient. This result is consistent with
the experiment and gives a novel theoretical picture for the quantum critical
point in heavy fermion systems.Comment: 4 pages, 3 figures, submitted to Physical Review Letter
An infrared measurement of chemical desorption from interstellar ice analogues
In molecular clouds at temperatures as low as 10 K, all species except
hydrogen and helium should be locked in the heterogeneous ice on dust grain
surfaces. Nevertheless, astronomical observations have detected over 150
different species in the gas phase in these clouds. The mechanism by which
molecules are released from the dust surface below thermal desorption
temperatures to be detectable in the gas phase is crucial for understanding the
chemical evolution in such cold clouds. Chemical desorption, caused by the
excess energy of an exothermic reaction, was first proposed as a key molecular
release mechanism almost 50 years ago. Chemical desorption can, in principle,
take place at any temperature, even below the thermal desorption temperature.
Therefore, astrochemical net- work models commonly include this process.
Although there have been a few previous experimental efforts, no infrared
measurement of the surface (which has a strong advantage to quantify chemical
desorption) has been performed. Here, we report the first infrared in situ
measurement of chemical desorption during the reactions H + H2S -> HS + H2
(reaction 1) and HS + H -> H2S (reaction 2), which are key to interstellar
sulphur chemistry. The present study clearly demonstrates that chemical
desorption is a more efficient process for releasing H2S into the gas phase
than was previously believed. The obtained effective cross-section for chemical
desorption indicates that the chemical desorption rate exceeds the
photodesorption rate in typical interstellar environments
Restoration of isotropy on fractals
We report a new type of restoration of macroscopic isotropy (homogenization)
in fractals with microscopic anisotropy. The phenomenon is observed in various
physical setups, including diffusions, random walks, resistor networks, and
Gaussian field theories. The mechanism is unique in that it is absent in spaces
with translational invariance, while universal in that it is observed in a wide
class of fractals.Comment: 11 pages, REVTEX, 3 postscript figures. (Compressed and encoded
figures archived by "figure" command). To appear in Physical Review Letter
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