14,470 research outputs found
Electronic Structures of Antiperovskite Superconductor MgCNi and Related Compounds
Electronic structure of a newly discovered antiperovskite superconductor
MgCNi is investigated by using the LMTO band method. The main contribution
to the density of states (DOS) at the Fermi energy comes from Ni
3 states which are hybridized with C 2 states. The DOS at is
varied substantially by the hole or electron doping due to the very high and
narrow DOS peak located just below . We have also explored
electronic structures of C-site and Mg-site doped MgCNi systems, and
described the superconductivity in terms of the conventional phonon mechanism.Comment: 3 pages, presented at ORBITAL2001 September 11-14, 2001 (Sendai,
JAPAN
Studies on the Density of Soybean Aphids in Different Cultivars, Planting Dates and Spacings
In order to evaluate the fluctuation of the soybean aphid (Aphis glycines Matsumura) population, six leading soybean cultivars were planted on five different planting dates with different plant densities. The survey of aphid population and climate condition was made from June through September in 1978. According to the differences of planting dates and plant density the soybean aphid populations were varied, and varietal response to the aphid was significantly different. Counting of aphid infestation on the top third trifoliate leaf seemed to be efficient for the estimation of soybean aphid population.Originating text in Korean.Citation: Chung, K. H., Kwon, S. H., Lee, Y. I. (1980). Studies on the Density of Soybean Aphids in Different Cultivars, Planting Dates and Spacings. Journal of the Korean Society for Crop Science, 25(3), 35-40
Charge and Orbital Ordering and Spin State Transition Driven by Structural Distortion in YBaCo_2O_5
We have investigated electronic structures of antiferromagnetic YBaCo_2O_5
using the local spin-density approximation (LSDA) + U method. The charge and
orbital ordered insulating ground state is correctly obtained with the strong
on-site Coulomb interaction. Co^{2+} and Co^{3+} ions are found to be in the
high spin (HS) and intermediate spin (IS) state, respectively. It is considered
that the tetragonal to orthorhombic structural transition is responsible for
the ordering phenomena and the spin states of Co ions. The large contribution
of the orbital moment to the total magnetic moment indicates that the
spin-orbit coupling is also important in YBaCo_2O_5.Comment: 4 pages including 4 figures, Submitted to Phys. Rev. Let
Electronic structures of doped anatase : (M=Co, Mn, Fe, Ni)
We have investigated electronic structures of a room temperature diluted
magnetic semiconductor : Co-doped anatase . We have obtained the
half-metallic ground state in the local-spin-density approximation(LSDA) but
the insulating ground state in the LSDA++SO incorporating the spin-orbit
interaction. In the stoichiometric case, the low spin state of Co is realized
with the substantially large orbital moment. However, in the presence of oxygen
vacancies near Co, the spin state of Co becomes intermediate. The
ferromagnetisms in the metallic and insulating phases are accounted for by the
double-exchange-like and the superexchange mechanism, respectively. Further,
the magnetic ground states are obtained for Mn and Fe doped ,
while the paramagnetic ground state for Ni-doped .Comment: 5 pages, 4 figure
Numerical simulation of pullout behavior of embedded suction anchors in clay
As the offshore wind power tends to locate farther from the coast for efficient generation of electricity,\ud
the interest of foundation systems of which construction sequence is economical and convenient under deep water\ud
circumstance is increasing. Mooring anchor system has been utilized as one of the most popular ways for anchoring of\ud
vessels or floating structures, and various types of anchor and mooring system have been investigated for large\ud
structures under diverse loading condition. In this paper, the pullout behavior of the modified embedded suction anchor\ud
(ESA) is studied using numerical analysis. The behavior of the embedded suction anchor is simulated using finite\ud
element method, and Adaptive Meshing (AM) technique approach incorporated in Abaqus/Explicit is applied to\ud
simulate the large deformation of soil caused by continuous pullout of anchor. The three dimensional modeling is\ud
performed to duplicate the round body shape with flanges of the embedded suction anchor. The anchor is assumed as\ud
rigid body and clay is considered as a linear elastic-perfectly plastic soil model with a Tresca yield criterion. The\ud
pullout capacities after different initial rotations show similar results with the maximum horizontal pullout capacity and\ud
the load inclination of 30?? or 40?? at the bottom point of the ESA has an advantage in that reduced pullout load can rotate\ud
the ESA
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