88 research outputs found
Mechanism of magnetism in stacked nanographite: Theoretical study
Nanographite systems, where graphene sheets of the orders of the nanometer
size are stacked, show novel magnetic properties, such as, spin-glass like
behaviors and the change of ESR line widths in the course of gas adsorptions.
We theoretically investigate stacking effects in the zigzag nanographite sheets
by using a tight binding model with the Hubbard-like onsite interactions. We
find a remarkable difference in the magnetic properties between the simple A-A
and A-B type stackings. For the simple stacking, there are not magnetic
solutions. For the A-B stacking, we find antiferromagnetic solutions for strong
onsite repulsions. The local magnetic moments tend to exist at the edge sites
in each layer due to the large amplitude of wavefunctions at these sites.
Relations with experiments are discussed.Comment: PACS numbers: 75.30.-m, 75.70.Cn, 75.10.Lp, 75.40.Mg; E-mail:
[email protected]; http://www.etl.go.jp/~harigaya/welcome_E.htm
Magnetic Structure of Nano-Graphite Moebius Ribbon
We consider the electronic and magnetic properties of nanographite ribbon
with zigzag edges under the periodic or Moebius boundary conditions. The zigzag
nano-graphite ribbons possess edge localized states at the Fermi level which
cause a ferrimagnetic spin polarization localized at the edge sites even in the
very weak Coulomb interaction. The imposition of the Moebius boundary condition
makes the system non-AB-bipartite lattice, and depress the spin polarization,
resulting in the formation of a magnetic domain wall. The width of the magnetic
domain depends on the Coulomb interaction and narrows with increasing U/t.Comment: 4 pages; 6 figures; published at J. Phys. Soc. Jpn. Vol. 72 No. 5 pp.
998-1001 (2003
An improved competitive inhibition enzymatic immunoassay method for tetrodotoxin quantification
Quantifying tetrodotoxin (TTX) has been a challenge in both ecological and medical research due to the cost, time and training required of most quantification techniques. Here we present a modified Competitive Inhibition Enzymatic Immunoassay for the quantification of TTX, and to aid researchers in the optimization of this technique for widespread use with a high degree of accuracy and repeatability
Initial antibodies binding to HIV-1 gp41 in acutely infected subjects are polyreactive and highly mutated
Many HIV-1 envelope-reactive antibodies shortly after HIV-1 transmission may arise from crow-reactive memory B cells previously stimulated by non-HIV-1 host or microbial antigen
Exciton/Charge-transfer Electronic Couplings in Organic Semiconductors
Charge transfer (CT) states and excitons are important in energy conversion processes that occur in organic light emitting devices (OLEDS) and organic solar cells. An ab initio density functional theory (DFT) method for obtaining CTâexciton electronic couplings between CT states and excitons is presented. This method is applied to two organic heterodimers to obtain their CTâexciton coupling and adiabatic energy surfaces near their CTâexciton diabatic surface crossings. The results show that the new method provides a new window into the role of CT states in excitonâexciton transitions within organic semiconductors.United States. Dept. of Energy (DEFG02- 07ER46474)David & Lucile Packard Foundation (Fellowship
The impact of being homeless on the unsuccessful outcome of treatment of pulmonary TB in SĂŁo Paulo State, Brazil
Strong expression of polypeptide N-acetylgalactosaminyltransferase 3 independently predicts shortened disease-free survival in patients with early stage oral squamous cell carcinoma
Protein Free Energy Corrections in ONIOM QM:MM Modeling: A Case Study for Isopenicillin N Synthase (IPNS)
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