504 research outputs found
Lidar measurement of stratospheric aerosol at Syowa Station, Antarctica
Lidar measurement on Antarctic aerosols were made during the Antarctic Middle Atmosphere (AMA) period, 1983 to 1985, at Syowa Station. Topics measured are winter enhancement aerosol layer and volcanic effect of El Chichon on the Antarctic stratosphere aerosols. The large depolarization ratio (maximum value was about 0.8) seems to support sublimation growth of ice crystals. The lidar measurements showed a meaningful time lag between aerosol content increase and depolarization ratio increase. Considering the balloon observations made in early winter, it was speculated that an increase in large particle number concentration also contributed to the winter enhancement. The El Chichon cloud spread to the Antarctic region by the beginning of 1983. The temporal change of integrated backscatter coefficient shows a clear decay pattern, although strong winter enhancement superposes
Analytically Solvable Mean-Field Potential for Stable and Exotic Nuclei
Slater determinants built from the single-particle wave functions of the
analytically solvable Ginocchio potential are used to approximate the
self-consistent Hartree-Fock solutions for the ground states of nuclei. The
results indicate that the Ginocchio potential provides a good parametrization
of the nuclear mean field for a wide range of nuclei, including those at the
limit of particle stability.Comment: 11 pages, LateX, 3 postscript figures. Submitted to Physical Review
Letter
Lidar observation of the mesospheric sodium layer in Antarctica
The mesospheric sodium layer has been observed at Syowa Station in Antarctica during the wintering period of the 26th Japanese Antarctic Research Expedition. A lidar observation of the polar middle atmosphere at the station has been performed as a part of the Middle Atmosphere Program since 1983. At first stratospheric aerosols have been observed by the system based on a ruby laser. In 1985 a new transmitting system consisting of a tunable dye laser was added to that system to observe the sodium layer, too. The characteristics of the lidar system are given. The results of the mesospheric sodium layer observed on 42 nights during the period from March to October, 1985 are also given
An Experimental Study on Relationship Between Intellectual Concentration and Personal Mental Characteristics
1st International Conference on Human Systems Engineering and Design (IHSED2018): Future Trends and Applications, October 25-27, 2018, CHU-Université de Reims Champagne-Ardenne, France.As a proposal of new diagnosis for mental diseases, this study focused on the relationship between intellectual concentration and personal mental characteristics. It is expected that the measurement of concentration characteristics may help the diagnosis of the mental disorders because the mental characteristics such as psychiatric disease, developmental disorder and behavioral feature are supposed to be closely related to their mental activity such as concentration. When analyzing the relationship, the characteristics of concentration are expressed as 36 feature values by analyzing answering time distribution of cognitive task, and the values of concentration were compressed to 5 main factors by principal component analysis. Then the combination of the factors and one of 36 parameters of mental characteristics were given to a decision tree analysis tool
Multiple Polar Cap Arcs: Akebono (Exos D) Observations
Akebono (Exos D) observations demonstrate that polar cap arcs sometimes have a fine structure, that is, multiple (double or triple) arcs with spacing of a few tens of kilometers. The multiple polar cap arcs are dominantly observed in the nightside polar cap region, suggesting that low background conductance favors the appearance of the structured arcs. A relationship between the spacing and the average energy of the precipitating electrons is investigated. Results show that a higher energy leads to a wider spacing. Akebono observations also show the existence of a downward current region embedded between upward current regions (arcs). Comparison of the observations with results from a coupled magnetosphere-ionosphere Sun-aligned arc model is made, which shows good qualitative agreement between the modeling and observational results on the spacing-energy dependence and the effect of background ionospheric conductance
Investigation of initiation of gigantic jets connecting thunderclouds to the ionosphere
The initiation of giant electrical discharges called as "gigantic jets"
connecting thunderclouds to the ionosphere is investigated by numerical
simulation method in this paper. Using similarity relations, the triggering
conditions of streamer formation in laboratory situations are extended to form
a criterion of initiation of gigantic jets. The energy source causing a
gigantic jet is considered due to the quasi-electrostatic field generated by
thunderclouds. The electron dynamics from ionization threshold to streamer
initiation are simulated by the Monte Carlo technique. It is found that
gigantic jets are initiated at a height of ~18-24 km. This is in agreement with
the observations. The method presented in this paper could be also applied to
the analysis of the initiation of other discharges such as blue jets and red
sprites.Comment: 12th International Congress on Plasma Physics, 25-29 October 2004,
Nice (France
Shell Model Study of the Neutron-Rich Nuclei around N=28
We describe the properties of the neutron rich nuclei around N=28 in the
shell mode framework. The valence space comprises the shell for protons an
the shell for neutrons without any restriction. Good agreement is found
with the available experimental data. The N=28 shell closure, even if eroded
due to the large neutron excess, persists. The calculations predict that
S and S are deformed with and
respectively.Comment: 17 pages and 19 figures, LateX, RevTe
Hyperfine Anomaly of Be Isotopes and Anomalous Large Anomaly in Be
A new result of investigations of the hyperfine structure (hfs) anomaly in Be
isotopes is presented. The hfs constant for Be is obtained by using the
core plus neutron type wave function: . A large hfs anomaly of Be is found, which is mainly due
to a large radius of the halo single particle state.Comment: 14 pages, Late
Effective density dependent pairing forces in the T=1 and T=0 channels
Effective density dependent pairing forces of zero range are adjusted on gap
values in T=0,1 channels calculated with the Paris force in symmetric nuclear
matter. General discussions on the pairing force are presented. In conjunction
with the effective k-mass the nuclear pairing force seems to need very little
renormalization in the T=1 channel. The situation in the T=0 channel is also
discussed.Comment: 6 pages, 8 figures, to be published in PR
Transfer/Breakup Modes in the 6He+209Bi Reaction Near and Below the Coulomb Barrier
Reaction products from the interaction of 6He with 209Bi have been measured
at energies near the Coulomb barrier. A 4He group of remarkable intensity,
which dominates the total reaction cross section, has been observed. The
angular distribution of the group suggests that it results primarily from a
direct nuclear process. It is likely that this transfer/breakup channel is the
doorway state that accounts for the previously observed large sub-barrier
fusion enhancement in this system.Comment: 4 pages; 3 figure
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